Well, to be fair, once a company is in the MS user pool, it is very hard to get out as MS Office is the norm in business. Now, the rent vs own is an interesting take on it. Most large businesses would rather not "own" software as it is often an asset that they have to track, amortize, and depreciate. Renting, or more ideally, annual licensing fits the fiscal year budgeting process much better. So having this as an option really fits the customer's business models better. However, for many companies, having your internet connection go down and losing the ability to function is far too much risk, so "owning" is the more prudent option. So long as MS offers both options, then they are addressing probably 90% of the market. Not really a big deal that they lost subscribers if people are still within the MS Office pool, but if it is a zero sum game (likely saturation) of Google docs vs Office 365 vs OpenOffice vs Other, then it becomes more of a question of whether "3rd party" office programs are slowly climbing their way to corporate acceptability. Having what I consider very few improvements, if any, since Office 2010, competition would be welcome to churn real innovation.
Scientific programming using Monte Carlo methods requires reproducibility based on some initial seed so that an analysis can be reconstructed. A good example of this is benchmarking a code for changes in compiler options. If the code is widely distributed, then a large set of random numbers is not as easily distributed as a Twister or other method. Also there would be problems with acceptability of the results of such a code if a developer were to distribute the code with a specific input and set of random numbers. The temptation to cherry pick results would be too high. For security purposes, where a one-time-pad approach is ideal, a truly random number is fine.
I don't particularly buy the authors approach though, because semiconductor physics is full of things that seem random at the moment, but then turn out to be entirely predictable once a suitable model is found. Sun Microsystems found this out years ago when they tried to base a random number generator based on the rate of soft failures from memory chips. They were using Boron as a dopant, which has a high probability of absorbing neutrons and decays with an alpha particle (He +2 atom), causing a hardware error. They claimed they had a perfect random number generator until they saw that the randomness was dependent on the location of the chips. Denver has more cosmic radiation than Miami, thus the randomness was actually Poisson (as are most things nuclear). The method was thus vulnerable to an attack based on the mean number of failures, which could be determined by knowing the physical location of the device.
Reactors are not becoming more complex, that is a key thing on which the industry, both vendors and utilities, can agree upon with the anti-nukes out there. Complex reactors cause accidents because humans aren't that great at dealing with pressure. So the next generation of reactors, termed Gen IV, are relying on passive safety systems that require little if any human interaction. If something goes wrong, the reactor defaults to a controlled state whether it be a huge loss of coolant accident (LOCA) or otherwise. Before you go saying that legacy reactors are overly complex, massive upgrades and plant optimizations in both control and safety systems have been performed over the last 15 years. Introduction of passive safety systems have significantly lowered PRA's (probabilistic risk assessment) across the board. No one is saying that nuclear power may be a cure all, but it is a prolonged solution that has proven to be quite viable whether people approve or disapprove of it.
Renewable energy would be great it if works. I would love nothing more than to have my house off-grid, if only because of the "coolness" factor. Unfortunately, some renewable forms aren't good everywhere, and people even complain about those. Wind power isn't favored by some because it kills birds or ruins their landscape. Some people don't like the look of solar panels, so many home owners associations have banned their use in their neighborhoods. So unfortunately, while renewables are a hot topic right now, they still have to contend with people's preferences, no matter how petty they are.
I'll say again, it is pretty hard to separate tritium. It's bound in water molecules first of all, so the only way you can really separate it is with gravity-derived methods as there are no chemical differences. The weight difference is fractional, 20g/mol for tritiated water vs 18g/mol for regular. Now, the Canadians use natural uranium reactors with heavy water, D20, well that component of the reactor is very expensive. Separating tritium out of water is ridiculously more expensive as the massive amount of cooling water that is passed through a centrifuge would require quite a large system with a low separation efficiency per CCF of water. Looking at the cross section of hydrogen then deuterium, this double absorption of a neutron isn't going to be a very large product, which is why it is chosen as the moderator in the first place, so very small quantities are produced. The activity is high because of the relatively short half life, not a massive quantity. Now if you do a separations facility for the tritiated water, you would have to either couple it directly to the coolant of the plant or devise a shielded transportation method. Obviously, the coupled method would work the best. Now, you'll also have water at elevated temperatures, probably saturated, so the density will be lower. The loss of thermal efficiency from the separations facility would be huge as you would either have to reheat the feedwater before it enters the reactor, otherwise you'll have a rather nasty reactivity swing, or run the reactor at a much lower power for control reasons. If you see where I'm going with this, you'll see why tritium isn't separated out like this in commercial reactors. The economic cost of producing tritium this way is far more than the benefits would be.
Carbon-14 is low in coal because of its short half-life and atmospheric origin. Uranium and thorium are present in coal, but do not undergo the accelerated fission that occurs in nuclear reactors and so release daughter species at the natural rate rather than concentrating the very hot waste produced by reactors. Owing to the long half-life of uranium, the radioisotopes of iodine or cesium are rarely produced. It would be better to not burn coal, but sulfur, carbon and mercury are much higher reasons to avoid it than trace uranium and thorium.
I'm not sure where you were trying to go with this, but C-14 is a very large release of coal burning, not uranium or thorium. C-14 really won't do too much to anyone in terms of dose, but in terms of total radioactivity, this release is far greater than any other from nuclear.
Braidwood is an example of what I was talking about in that plants releasing tritium. They released more than normal at a few given instances, but there is still quite a bit that is released that is under the radar of most people. Suppose that you only hear about the company that released 1.01 billion tons of sulfur when it is illegal to release more than 1 billion tons. Other companies can go along releasing.99 billion tons of sulfur without hearing any complaints, but is the one that released a little fraction more unsafe and a horrible example for the entire industry? I'm making up the sulfur example, but hopefully you see my point as it is true in the nuclear industry as in the chemical industry. The legal limit for tritium release is quite large, companies get around the limits by releasing in batches at various points down a river (if that is the method of release). This allows the water to diffuse most of the upstream tritium such that the concentration downstream is significantly lower, and thus well within legal limits. Braidwood released too much upstream and got caught. They should be rightly punished as it was technically against the law, but this is merely a law in semantics. Though shalt not steal turns into people borrowing things on a permanent basis.
Tritium isn't all that useful for the most part. The 12 year half life makes it have a short half life, and the cost of separations would be too large to extract it down to a concentration that may be useful. This is why tritium isn't used many places. I think even gun manufacturers moved away from tritium sights because it was too expensive. Helium-3 is different though. Tritium is hydrogen (1 proton) with 2 neutrons while helium 3 is a helium atom (2 protons) with 2 neutrons. There isn't much helium-3 so it is very valuable. After 9/11, it's become increasingly expensive because it is used in one type of neutron detector. Fusion people would be out of luck as helium-3 is too scarce to use as a fuel on this planet. However, the moon has quite a bit of helium-3 according to space nerds, so maybe the answer is mining the moon.
Well, the inert gas release at TMI is another of those law issues. Noble gases in a BWR build up into the water and must be removed. The question is, where does it go? Into the air of course, but when and how much depends on the air conditions that day. The gaussian plume model is still used (to the best of my knowledge) to calculate dispersion of radionuclides into the atmosphere. This looks like a hot air balloon rising from a tube. If the wind is blowing hard in the upper atmosphere, the balloon gets dispersed horizontally at that height, which is ideal because this lower the concentration very quickly as it spreads over a much larger area, but when the wind is faster at a lower altitude, the balloon would disperse over a much smaller area, which would not reduce the concentration as much, so a lower amount is allowed to be released. 13MCi is quite a bit of radiation; however, as this is dispersed over a large area, as was the case at TMI, the concentration is significantly small. Most of the inert radioactive gases have half lives well under a week, so this is essentially gone in a month before the high altitude air even has a chance to permeate the lower atmosphere. The final story on TMI is that the radiation released wasn't that bad, but because they couldn't get engineers in contact with the right people, the situation looked worse and worse.
Coal does release more radioactivity into the air every year (as C-14 et al) than any nuclear plant does. This usually gets a pass, but now that people are looking into emissions, they're seeing this and wondering why they haven't heard this before. Nuclear isn't the answer for all our power either. In many cases, it's more useful to go with wind, geothermal, or hydroelectric; however, depending on the location, these type
Most people don't know it, but tritium is constantly released from every boiling water reactor during normal operation, and not in insignificant amounts either; however, the effect to people/animals/plants is negligible. At TMI slightly greater amounts, than normally licensed for release, did diffuse into the ground, but with such a short half-life and it being a primary component of water, it makes people feel uneasy. In the health physics industry, tritium largely isn't considered that much of a health hazard, especially when it is diffused over a large area making the concentration rather small, as was the case with TMI and is the case with every BWR in the world. In fact, were it to be ingested in large amounts at once, it would still be far less dosage than flying a plane cross-country. Most people think of contamination breaching the reactor as being radioactive iodine or some other fission product. None of that was released in TMI, thus containment designs worked as they were intended.
Unions aren't always to blame for this, I do agree that this seems like an issue with their management. The us-vs-them mentality kills any large work environment regardless of the industry. Their stockholders will be furious if the plant gets a NRC infraction causing a long downtime, thus reducing their profits greatly. If it turns out to be a problem at all of their plants, then I hope you don't have money invested in the energy sector because the entire industry will suffer. Generally, plants do pretty darn well with maintenance, but problems do happen. At the Shearon Harris plant outside of Raleigh, NC, there were quite a few problems years ago when the company was still Carolina Power and Light. Operators would press the wrong button when hearing an alarm (which happens about every 15 seconds as something needs to be bumped somewhere on an older instrumentation plant, which isn't the case with updated computer instrumentation mechanisms), causing an unplanned shutdown. The NRC told them to clean their act up, and since then it's had a pretty flawless record. So hopefully this won't cause too much harm to the industry, but it could if they let this kind of thing happen.
As far as reactor design goes, TMI was a overwhelming success as far as the containment structure went. On the other hand, their public relations was a abysmal failure, which is why people generally think that nuclear power may be unsafe. Had their incident response been better planned, it would not have snowballed into as big an event as it did. During and after the event, no radioactivity of any significance was released as a result of the safety mechanisms built into the design. So really, it was proof that even in the event of a loss of coolant accident, the design is still safe. After that incident in 1979, mind you that it was nearly 3 decades ago when nuclear power was in its adolescence, what other large failures have happened outside of fuel processing facilities? None.
A SCRAM is nothing on the safety of the plant, the safety is in the design of the redundant active and passive safety systems and containment. A SCRAM usually means operator error, which is why most plants are moving to digital instrumentation, control, and logging. Now I grant you that SCRAM's are not good events, as they cost the utility quite a bit of money and require NRC approval to restart after review of the events leading to the shutdown. With a reactor operating at nearly 1 GWe, that is quite a bit of revenue lost just in electricity production, not to mention the more expensive coal systems that have to be started to support the grid during the outage. So utilities don't want unplanned shutdowns, so their maintenance and operations records are usually spotless. That is why the industry as a whole have achieved a capacity factor over 90%, greater than any other type of electricity production. Utilities want clean safety records and to have their plants running as long as possible because it's more profitable that way. An ungreased valve at this plant was a maintenance error, and will probably result in that guy being fired (if he can be). I completely agree that redundancy in checking of work is necessary, and it is required in every plant so I'm not sure why they missed this (my guess is below). The risk of losing millions as opposed to hiring another maintenance worker at $50,000 per year is insignificant, so there really is no excuse for an ungreased valve.
My own opinion, after seeing how some plants get screwed when dealing with unionized workers, is that the maintenance crew had a few issues with workers taking sick days during the outage as a retaliation for something, resulting in fewer people to work. Instead of delaying the restart, they chose to over-task those fewer workers and try to make the scheduled restart, resulting in their loss of millions of dollars of revenue, not to mention the bad PR. Bad PR in the nuclear industry is something no utility can afford, so they'll likely be on the S-list of the NRC for a while. In my opinion, unions in this country should take a good hard look at how the auto workers signed their own pink slips by screwing the manufacturers into moving overseas and south of the border. Forcing your employers hand is only going to raise the risk of putting many people out of a job.
Refuelings can be performed faster these days because employees go through multiple dry-runs for the refueling and repairs before the system is brought off-line. This reduces exposure to maintenance crews and engineers. I can't fault them for going faster as the methods used across the entire industry are nearly identical and work over 99% of the time (103/104). Could it be a systematic problem at the plant? Maybe, as the number of tasks increase while the time each employee spends in the containment area decreases, you are bound to get a forgetful maintenance worker here and there; however, the goal of the dry-runs and checklists is to make sure that there are no forgetful maintenance workers. So this could be an issue with the administration there. If you have enough plants, the chances are that there will be issues like this at one of them at some point. The better part of this is that as these issues arise, the industry takes measures so that they don't happen again. Overall, the safety of nuclear plants in the US is spectacular.
Think back to grade school. You're sitting there taking a course that you didn't want to take but had to because the school chose it for you. You have no freedom of choice. I'm all for core curriculum as in math, science, language, and social studies, which is primarily what your first year of college is spent doing anyway. It does make you more balanced and gives a reasonable baseline. Students involved in AP or gifted programs have more options to study what they want, but it's those kids who aren't that need something to work towards. If you're interested in science and math, you have a science curriculum, if you're interested in business, then you have a mixture of economics and social studies. The idea of having targeted paths for students is great, in my opinion. For students that may change their minds, make the "major" be more like a minor. You take so many science classes for a science concentration, etc, while the core classes make up the real "major." In this case, the school seems to be making this a bit harder than it needs to be, but I think they're on the right track at least. High school is bad enough, so let the kids at least take classes that they want.
From an IT perspective, I completely understand Microsoft's shift towards having the home basic, home premium, business, enterprise, and ultimate versions. Why do you need media center capability in the office? And why would anyone at home need remote desktop? Well, I do and I'm sure a lot of other people do too. I don't want to be charged the Windows Tax on a new laptop and get an inferior product when compared to good ol' XP. I don't care if it has swoopy graphics, Beryl does that for free in Linux, but few retailers are willing to offer a no-OS/Linux option on a new machine for fear of upsetting the powers that be. I don't think I should have to pay the huge premium for the Ultimate version either, especially when it isn't offered by an OEM source to come pre-installed, but rather through the ridiculous upgrade program. Because I want to sit at the computer twice as long to get my desktop back if windows has a hiccup and won't boot. Lastly, why price the ultimate version at $399 MSRP? Are they banking on the idea that "gamers" or "power users" will have extra money to dish out for an OS that wastes their hardware resources? Or would that money be better spent on more ram or faster processor and an un-neutered copy of XP? I love Linux and have been a fan of Windows for years (since WFW 3.11), so I have no hatred of Windows (which may get this modded down), but their new sales plan is silly and annoying. I don't want to spend hundreds of dollars on a full version (I abhor upgrade versions and have since Windows 98), let alone select whether or not I want to go 64-bit with it at time of purchase if I don't want to wait/pay for MS to ship another DVD installer. I'll be staying away from Vista until the prices drop and problems start to disappear. Right now I have machines that all work, so why risk the headache?
Tests with liquid sodium have been very successful. In France, the Phenix/Superphenix designs have used liquid sodium for over 3 decades without incident. EBR-I and EBR-II used liquid sodium without problems (~1960's to 70's if I remember correctly). Oddly enough, the stainless steel (SS-304) assemblies came out of EBR-II after nearly 200 GWd of burnup looking brand new and shiny, which is kind of creepy when comparing that to spent assemblies from a LWR (light water reactor) after 33 to 60 GWd of burnup. The sodium cooled design is actually better in a LOCA (loss of coolant accident) than a traditional LWR. I agree there are some drawbacks to the sodium cooled design, such as keeping the coolant hot during fuel shuffles and potential water reactions in the secondary steam cycle, but as far as materials go, the sodium works much better with longer lasting burnups for fuel. Right now, from a fuels standpoint, we could manage the fuel in a LWR to burn up to nearly 100 GWd, which would use less fuel and reduce cost to utilities, but it's a materials limitation on the zircaloy cladding and assemblies. Water/steam at high temperatures is about the nastiest stuff imaginable when mixing with standard materials and it gets even worse as it is exposed to radiation (creates multiple free radicals during the neutron moderation process and gamma shielding). It literally eats away the cladding, giving a theoretical fuel lifetime (before failure and release of fission gasses into primary coolant) of ~70GWd/mton of fuel. Of course, that's without the safety factors added, which reduces to around 55GWd/mton (mton being metric tonne). There's an old NUREG (NRC regulations so should be a public document), number 1368 I think, that is an initial safety evaluation report on the viability of then GE/ANL designed ALMR (Advanced Liquid Metal Reactor, later termed PRISM and subsequently Super PRISM). If you want to see some of the nuclear side of it, there's a paper from ICONE-8 in 2002 on the design of the reactor giving some basic core specs but no fuel composition as that would be in the applied technology report that is kept as a trade secret. In any case, sodium cooling may seem counter-intuitive, but it's actually a very tested and mature technology.
The US designed sodium cooled reactor, SuperPRISM (formerly PRISM and ALMR), does create plutonium during a 150-180GWd burnup for both metal and oxide fuels. The question is which plutonium does it create. Only Pu-239 is useful in a bomb, while the other isotopes act primarily as fissionable poisons (low nu-bar value), but that's what you have in your driver fuel, so you have to separate that out anyway before fuel fabrication to make sure the isotopic concentrations are correct for startup. This requires a plutonium separating reprocessing step, which is exactly what the non-proliferation crowd doesn't want (IMHO, they really don't see that stable countries have no diversion, but refuse to leave their "treat every country equally" stance even though it's a long term economic and environmental benefit). The SuperPRISM design creates higher n- isotopes of plutonium. In fact, Pu-241 is the only produced in significant numbers that isn't further transmuted into Am-241, -242m, -243 or Cm-244. PUREX will probably not be used for commercial purposes (given the civilian reluctance to use certain military technologies), but rather some other modified form of the Japanese DIDPA or French DIAMEX solvent extraction processes. The disposal problems for spent LWR fuel have to go through the politics before anything can happen. After years of work, I have come to the conclusion that it's politicians who will make the decision based on whichever engineer has the flashiest powerpoint presentation and promise of pork for their state rather than an engineer who has an optimal and well constructed plan.
In the US, many jobs require using a computer every day for 8 hours while at the office. In the opinion of many that I know and have worked with, they don't see why they would want to sit in front of a computer for a few more hours when they get off work. This isn't a US vs rest of the world thing, it's apathy! Why sit in front of the computer typing away every night when you do it all day at work? That's what it comes down to for most of the baby boomer generation. For younger generations, it is probably borrowing their neighbor's wifi connection. For the 22% who said that they can't afford a computer, they didn't ask them if they could afford smoking either. So it's my opinion that the survey is somewhat incomplete and skews results in a certain way to make it look like much of the US is a backwards society when that's really not case. Some people just don't care about technology. Having other priorities and interests is not a bad thing.
For as much as I've been flying in the past few years, I've come into contact with cases of "Parents won't make their kid shut up rage," "Baby won't stop crying rage," or my favorite "that damn kid behind you won't stop kicking your seat and if you say anything else the flight attendant is going to ground the airport and have you arrested rage." I can only imagine where the "Teenaged girl won't stop saying 'like oh my god she did not!' while on the phone with each of her moron friends rage" might take us. I bet this is really a build up to airlines offering a new class of seating on the planes, "Quiet First Flass: where cell phones and children are not allowed."
I couldn't agree with you more. Just because something is correlated does not mean that they are actually related. Just because a country has cable means that children born and raised there have an elevated risk of mental disorders? What about the fact that cable is more prevalent in more affluent nations? I would assume that GDP be well correlated to a chance of autism. Why not look at amount of prenatal health care and draw a correlation from that. At a conference I heard a good argument that the increase in prenatal tampering (oversampling of ambiotic fluid, administering certain drugs to induce labor, excessive ultrasound images) in the US could be related to chances of childhood illnesses. Actual relations between administration of some oft prescribed drugs during a pregnancy have proven damaging to a child, but I'm sure TV is the real cause (a little sarcasm). You said it, this is scientific pornography.
I got my fiance stuck on linux after making her laptop run with kde on gentoo using the xcomposite module to make it look pretty (that and she thinks the penguin is cute). I've tried to explain to her why I have to compile everything, but she still says "Isn't it easier to just make one file that will run on all of them?" As much as I hate to say it, she's right, which is why windows has the advantage. As the variations on hardware are seemingly infinite, the possibility of compatibility is much larger when the executables aren't optimized for each individual platform, but rather run in a compatibility mode (rather -mcpu=i386). While it may not seem too hard to compile our systems, the average person doesn't want to. Instead, they just want it to work with minimal effort. So I figure that every normal user needs a personal tech support person to set up and support their linux box if it's going to take off the way most linux zealots think it should.
Ahhh nostalgia.... Here's my story, after I picked up a 286 computer with an EGA monitor and a whopping 210 megs of hard disk space off of a building company when their power flickered, I changed out the power supply and I was online shortly with a 2400 baud modem. I was 12 at the time (1993). I found the Southeastern Information Depot (SID) and downloaded a list of atlanta area BBS's (Hacker's Layer, the Brick Wahl, etc). After that, it was onto some hacking and warez BBS's. I stayed on those until internet services weren't pay by the minute. Well I didn't feel old until just now:-) Anyone else frequent Atlanta area BBS's back in the day?
There's quite a bit of money being dumped into enclosed nuclear power sources that can be deployed to third world countries or disaster areas. The basic design is a trailer type (surprisingly not designed in the South) self contained core/coolant/generator using a rankine regen cycle to output a few megawatts of electricity. Low power core, but enough to create viable heat using helium. Do I think it'll make its way off paper? Of course not, who would? But you're right, RTG's on earth are a thing of the past (save some older pacemakers and oceanic beacons).
That might be possible. (I am thinking about the radioactive materials used as power sources on some spacecraft.) Unfortunately we couldn't get a whole lot of energy out of the process (or get very much "wattage"), so no one would bother.
Not much wattage using an RTG? This is how our deep space satellites have worked for over 30 years when the initial lifetime was expected to be less than half that. When the temperature of space is around 3K, the temperature gradient between a large mass of plutonium can be large enough to generate more than enough electricity for modern electronics to function. A few kW can power a large amount of electronics.
We could also put it back in the reactor, and we do this already. Not all of the useful uranium is gone after the spent fuel rods are pulled from the reactor, and what is left can be reprocessed and used again. That can't be repeated forever, though.
Just about all of the "useful" uranium is gone. Initial enrichment is between 4 and 5% U-235 with the rest being U-238 which converts into a decent amount of plutonium and higher actinides. Fuel at discharge has around 1-1.5% U-235 since we can't run the reactors that long due to degradation of the cladding (structural material). Reprocessing doesn't exist to reuse uranium, it's to harvest plutonium and higher actinides which can be burned in a mixed oxide (MOX) core or a fast reactor (uses only transuranic fuel). You're right that the reprocessing cycle cannot last forever, but as it stands, we barely do it now. Much of the MOX fuel we use now is from an agreement with Russia to destroy weapons grade plutonium by burning it in commercial reactors. After that, MOX probably won't be used since it is expensive and somewhat unnecessary since the cost of fresh uranium is pretty darned cheap. Once the costs go up, then reprocessing will be back in vogue again. Another consideration to your comment that reprocessing cannot last forever, is that we don't use fast reactors. A fast reactor uses higher actinides in a much smaller core to produce a much smaller amount of energy, but it burns that pesky plutonium, thus increasing repository space for long lived fission products. Fast reactors can either burn, break even, and even produce plutonium (and anywhere in between). This lengthens the potential nuclear fuel cycle quite a bit, assuming that oil and coal disappear and other power forms remain as weak as they are. But right now, it's economics and politics as to why this isn't done, because technology is there.
The current solution is waste vitrification where we seal the spent fuel into a borated glass mixture. Boron absorbs decay neutrons from the transuranics, so criticality issues are avoided when lumping lots of actinides. The problem is heat. Fission product heat loads are effectively gone within 200 years. The current idea of letting the waste sit in a spent fuel pool for 30 years (30 years is the usual cutoff for short/long lived fission produts), is the best and only option we have if we don't want to fill the maximum heat capacity of the repository within 20 years. The repository as it stands can fit as much mass as was removed from it to create the tunnels and storage area. Since there are structural materials and criticality checks all through there, the masses are somewhat spread out, but still rather close together until you look at the decay heat. After the first 30 years, the integral heat load is all actinides. The heat doesn't drop off for thousands upon thousands of years. In a mountain with passive cooling (meaning natural conduction through rock, not a good conductor), an integral heat load that is too high can raise the temperature of the repository to dangerous levels. To keep the temperature down, the waste is spread out, which decreases the actual mass capacity by far. Any reprocessing can raise the capacity of the repository from a factor of 4 to around 80 when removing the actinides from the long and short lived FP's. The reality hasn't changed one bit in the past 30 years, reprocessing is still not going to happen until the cost of uranium increases to the point where it's more economical to reprocess than to purchase new fuel. Eventhough Carter tossed aside the american reprocessing efforts, the main factor for why it hasn't come back is pure economics.
To cite a good presentation at a conference: Preston, Jeff. "The Influence of Fuel Cycle and Spent Fuel Characteristics on Repository Heat Loads." Transactions of the American Nuclear Society, Vol 94. 2006.
It is pretty easy to shield using water, since that's how spent fuel is stored after discharge from commercial plants until it's cool enough to move to dry storage (temperature cool, not radiation). Dry storage works just fine once the thermal loadings are low enough. Casks such as this are present at nearly every nuclear facility that hasn't moved fuel offsite.
My question about doing this on a large scale, is how are you going to keep this much material cool enough to reduce the half life assuming that this works in the first place? Alpha emission of transuranics has around 6.5 MeV of energy per particle, which translates into a large amount of heat for not so large amounts of material. The coolant material to waste ratio would be enormous! Also, the refrigerant energy to do this would probably render the entire process even more inefficient than the current idea of reprocessing (remember that reprocessing has lots of particularly nasty chemicals associated in large quantities). Since alpha emitting isotopes are neutron rich, meaning they are either fissile or fissionable, they can be used as fuel. Why destroy fuel when you can burn it? At worst, continue MOX reprocessing as is currently done. At best, fuel some RTG's for space exploration. In my mind, this type of research is "neat" at best, but if the purpose is trying to force schrodinger's cat back into the bag, they can forget it now that global warming is becoming a hot issue with nuclear power the sole possibility for continuing the current growth rate of electricity demand (way too many puns there, I apologize).
For learning purposes, you can save a lot of headaches by setting up a VWware linux setup and do snapshots so you can roll back when you do something that screws up the system (had a guy try to set up an NFS server and ended up formatting the/usr directory, how that happened, I don't know). It's also quite nice as a testing platform since the vmplayer is free. What that means, is if you have a room full of computers that never get used (as I do in my undergraduate student's computer lab), I can run the vmplayer over windows as my user and let the students login separately. This is also kinda nice so that I can do a scripted active hosts file that updates the cluster setup so that I can have 2 or 20 machines without touching a conf file myself. Surprisingly, there isn't much cpu power lost when running the VM over windows, just network lag since I do the NAT option so I don't have to register new IP's. I run MPI to drive a distributed version of MCNP (neutron transport code) on my personal cluster (Rocketcalc with extra OTS PC's as extra nodes) and do the VM for fun/testing. Other than that, look at the Gentoo HPC howto's, MPI/PVM/LAM manuals, and try to plan out your cluster before starting. It's much easier to get things to work when you know what you're trying to do beforehand than to bumble through it and say "wouldn't it be cool if..."
Not encrypting the password hashes seems more like an ethical question for a sysadmin. First off, why even put yourself in the position to potentially have access to your user's personal info? I say this will full knowledge that there are people out there who use the same password for every single site they use thinking it's secure (no, I don't mean you mom). So even if a sysadmin doesn't do this with unethical intentions, he's still leaving his users info out in the open should a more unscrupulous fellow gain access to the system. At least hash with something as a deterrant. Best case scenario the person who breaks in will have to waste time cracking with john. Say myspace or facebook did this and the entire userbase had their passwords taken. How many college students probably use the same password on there that they do everywhere else? It would be a nightmare for some and a wet dream for spammers, carders, and others. There's just no reason that with all the hashing API's and OSS projects out there, that a sysadmin would be lazy enough not to encrypt the password list/database.
Cancer gene is misleading? That's where cancer comes from! Radiation and chemical effects of cancer change are present in the restructuring of DNA strands during the dna replication phases of cellular reproduction. That's why you have multiple treatments of x-rays for a cancer treatment, to kill cells that were in between reproductive cycles. And what rubber band is stretched? The replication sequence follows a straight path on the individual rna strands. It doesn't look at multiple locations on different strands before deciding to create a protein. If they created a stop codon that blocks unrestricted, accelerated cellular reproduction (cancer), then great. But if this affects the "soul gene," then I think James Brown might sue.
You're referring to low level waste. Water around a spent fuel pool is monitored and deionized constantly to keep it clean of contaminants that might get irradiated and create a health hazard, so there isn't a lot of associated activity with it, which is why it is called low level waste. Low level waste is sent to a processing/storage facility where it sits until the activity monitors drop to EPA's (or equivalent's) allowable levels, time scale less than 5 years usually. After that the stuff can be thrown in the garbage or recycled. Depending on the type of reactor, the water never leaves the core (PWR) or can leave the core (BWR). In the case that it does leave the core, the big issues are tritium (12 yr hl), nitrogen-16 (~14 minutes), and a few other short lived nuclides. Sites actively monitor material outputs, such as water, to make sure tritium levels are not exceeding the EPA limits. In the case of a few BWR's that have exceeded the limits, they have to go back and figure out where and how to fix it so that it doesn't happen. In any case, tritium has a biological half life of less than 5 days, so humans get a very tiny dose ( 1mSv) from a few mCi ingested. Other material such as structural supports for fuel bundles and cladding are stored with the fuel in the pool (of course) and in the dry storage after enough time has elapsed. The long term view, for Yucca (or any other geologic repository for that matter), is to store all of the material in a vitrified (borated glass) form. This means they would break all the waste down in either an acid or crusher and mix with molten glass to add a neutron absorbing, solid material around the waste to prevent any criticality accidents since we can't fight off the stigma that plutonium is evil. With this kind of long term waste storage, it would be a few thousand years before the radioactivity levels drop to that of natural uranium (cutoff for safe material is uranium ore). With large scale reprocessing using PUREX (Pu-Uranium-Extraction) and a few fast reactors the long term storage activity level drops from many thousands of years to around 300 years, if we do it right that is. That help?
From a dose assessment aspect, this is no surprise at all. The initial release was horrible on the wildlife populations; however, take a base assumption that biological effects of radiation differ for all species. As the Russell's found out in their "mega mouse" experiment at Oak Ridge, what is harmful to mice isn't necessarily harmful to humans and same thing with bears, deer, pigs, birds, etc. The initial release consisted largely of I-131, Cs-134/7, Sr-90, tritium, some actinides, and some other shorter lived fission products that primarily followed a modified gaussian plume model for the initial distribution to the air/soil. The I-131 was a huge dose at first, but with an 8 day half life, it was gone after a few weeks. Also keep in mind that not all species have large iodine uptake to the thyroid as do humans, so the initial release of I-131 would not have affected local populations as much in the first few weeks while the I-131 was still present. The Cs-134 and tritium is gone as well, and the Cs-137 will be around for another 100 years if the initial estimates were correct. Cross sectional species tests for osteosarcoma should be done to check for effects of Sr-90 in the bone to see how healthy the animals truly are (leukemia and blood disorders could be present), but even Sr-90 drops straight to the water table and I doubt these animals are drinking out of wells so their water supply is relatively clean compared to what a human would expect there. The external dose from actinide contamination in soil is extremely low as well, not as low as uranium ore, obviously, which is the standard, but still low enough not to cause a problem to wildlife since the uptake factor to plants is very low for actinides since they're so massive and the chemistry doesn't allow much at all. That said, leaves coated with dust from the fallout would be a large addition to the soil/vegetable ingestion dose for animals, but after a few generations of plants and many rinses in rain would render the leaves relatively clean of actinides. Nature finding a way to survive isn't surprising at all.
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Well, to be fair, once a company is in the MS user pool, it is very hard to get out as MS Office is the norm in business. Now, the rent vs own is an interesting take on it. Most large businesses would rather not "own" software as it is often an asset that they have to track, amortize, and depreciate. Renting, or more ideally, annual licensing fits the fiscal year budgeting process much better. So having this as an option really fits the customer's business models better. However, for many companies, having your internet connection go down and losing the ability to function is far too much risk, so "owning" is the more prudent option. So long as MS offers both options, then they are addressing probably 90% of the market. Not really a big deal that they lost subscribers if people are still within the MS Office pool, but if it is a zero sum game (likely saturation) of Google docs vs Office 365 vs OpenOffice vs Other, then it becomes more of a question of whether "3rd party" office programs are slowly climbing their way to corporate acceptability. Having what I consider very few improvements, if any, since Office 2010, competition would be welcome to churn real innovation.
Scientific programming using Monte Carlo methods requires reproducibility based on some initial seed so that an analysis can be reconstructed. A good example of this is benchmarking a code for changes in compiler options. If the code is widely distributed, then a large set of random numbers is not as easily distributed as a Twister or other method. Also there would be problems with acceptability of the results of such a code if a developer were to distribute the code with a specific input and set of random numbers. The temptation to cherry pick results would be too high. For security purposes, where a one-time-pad approach is ideal, a truly random number is fine.
I don't particularly buy the authors approach though, because semiconductor physics is full of things that seem random at the moment, but then turn out to be entirely predictable once a suitable model is found. Sun Microsystems found this out years ago when they tried to base a random number generator based on the rate of soft failures from memory chips. They were using Boron as a dopant, which has a high probability of absorbing neutrons and decays with an alpha particle (He +2 atom), causing a hardware error. They claimed they had a perfect random number generator until they saw that the randomness was dependent on the location of the chips. Denver has more cosmic radiation than Miami, thus the randomness was actually Poisson (as are most things nuclear). The method was thus vulnerable to an attack based on the mean number of failures, which could be determined by knowing the physical location of the device.
Renewable energy would be great it if works. I would love nothing more than to have my house off-grid, if only because of the "coolness" factor. Unfortunately, some renewable forms aren't good everywhere, and people even complain about those. Wind power isn't favored by some because it kills birds or ruins their landscape. Some people don't like the look of solar panels, so many home owners associations have banned their use in their neighborhoods. So unfortunately, while renewables are a hot topic right now, they still have to contend with people's preferences, no matter how petty they are.
I'll say again, it is pretty hard to separate tritium. It's bound in water molecules first of all, so the only way you can really separate it is with gravity-derived methods as there are no chemical differences. The weight difference is fractional, 20g/mol for tritiated water vs 18g/mol for regular. Now, the Canadians use natural uranium reactors with heavy water, D20, well that component of the reactor is very expensive. Separating tritium out of water is ridiculously more expensive as the massive amount of cooling water that is passed through a centrifuge would require quite a large system with a low separation efficiency per CCF of water. Looking at the cross section of hydrogen then deuterium, this double absorption of a neutron isn't going to be a very large product, which is why it is chosen as the moderator in the first place, so very small quantities are produced. The activity is high because of the relatively short half life, not a massive quantity. Now if you do a separations facility for the tritiated water, you would have to either couple it directly to the coolant of the plant or devise a shielded transportation method. Obviously, the coupled method would work the best. Now, you'll also have water at elevated temperatures, probably saturated, so the density will be lower. The loss of thermal efficiency from the separations facility would be huge as you would either have to reheat the feedwater before it enters the reactor, otherwise you'll have a rather nasty reactivity swing, or run the reactor at a much lower power for control reasons. If you see where I'm going with this, you'll see why tritium isn't separated out like this in commercial reactors. The economic cost of producing tritium this way is far more than the benefits would be.
I'm not sure where you were trying to go with this, but C-14 is a very large release of coal burning, not uranium or thorium. C-14 really won't do too much to anyone in terms of dose, but in terms of total radioactivity, this release is far greater than any other from nuclear.
Braidwood is an example of what I was talking about in that plants releasing tritium. They released more than normal at a few given instances, but there is still quite a bit that is released that is under the radar of most people. Suppose that you only hear about the company that released 1.01 billion tons of sulfur when it is illegal to release more than 1 billion tons. Other companies can go along releasing .99 billion tons of sulfur without hearing any complaints, but is the one that released a little fraction more unsafe and a horrible example for the entire industry? I'm making up the sulfur example, but hopefully you see my point as it is true in the nuclear industry as in the chemical industry. The legal limit for tritium release is quite large, companies get around the limits by releasing in batches at various points down a river (if that is the method of release). This allows the water to diffuse most of the upstream tritium such that the concentration downstream is significantly lower, and thus well within legal limits. Braidwood released too much upstream and got caught. They should be rightly punished as it was technically against the law, but this is merely a law in semantics. Though shalt not steal turns into people borrowing things on a permanent basis.
Tritium isn't all that useful for the most part. The 12 year half life makes it have a short half life, and the cost of separations would be too large to extract it down to a concentration that may be useful. This is why tritium isn't used many places. I think even gun manufacturers moved away from tritium sights because it was too expensive. Helium-3 is different though. Tritium is hydrogen (1 proton) with 2 neutrons while helium 3 is a helium atom (2 protons) with 2 neutrons. There isn't much helium-3 so it is very valuable. After 9/11, it's become increasingly expensive because it is used in one type of neutron detector. Fusion people would be out of luck as helium-3 is too scarce to use as a fuel on this planet. However, the moon has quite a bit of helium-3 according to space nerds, so maybe the answer is mining the moon.
Well, the inert gas release at TMI is another of those law issues. Noble gases in a BWR build up into the water and must be removed. The question is, where does it go? Into the air of course, but when and how much depends on the air conditions that day. The gaussian plume model is still used (to the best of my knowledge) to calculate dispersion of radionuclides into the atmosphere. This looks like a hot air balloon rising from a tube. If the wind is blowing hard in the upper atmosphere, the balloon gets dispersed horizontally at that height, which is ideal because this lower the concentration very quickly as it spreads over a much larger area, but when the wind is faster at a lower altitude, the balloon would disperse over a much smaller area, which would not reduce the concentration as much, so a lower amount is allowed to be released. 13MCi is quite a bit of radiation; however, as this is dispersed over a large area, as was the case at TMI, the concentration is significantly small. Most of the inert radioactive gases have half lives well under a week, so this is essentially gone in a month before the high altitude air even has a chance to permeate the lower atmosphere. The final story on TMI is that the radiation released wasn't that bad, but because they couldn't get engineers in contact with the right people, the situation looked worse and worse.
Coal does release more radioactivity into the air every year (as C-14 et al) than any nuclear plant does. This usually gets a pass, but now that people are looking into emissions, they're seeing this and wondering why they haven't heard this before. Nuclear isn't the answer for all our power either. In many cases, it's more useful to go with wind, geothermal, or hydroelectric; however, depending on the location, these type
Most people don't know it, but tritium is constantly released from every boiling water reactor during normal operation, and not in insignificant amounts either; however, the effect to people/animals/plants is negligible. At TMI slightly greater amounts, than normally licensed for release, did diffuse into the ground, but with such a short half-life and it being a primary component of water, it makes people feel uneasy. In the health physics industry, tritium largely isn't considered that much of a health hazard, especially when it is diffused over a large area making the concentration rather small, as was the case with TMI and is the case with every BWR in the world. In fact, were it to be ingested in large amounts at once, it would still be far less dosage than flying a plane cross-country. Most people think of contamination breaching the reactor as being radioactive iodine or some other fission product. None of that was released in TMI, thus containment designs worked as they were intended.
Unions aren't always to blame for this, I do agree that this seems like an issue with their management. The us-vs-them mentality kills any large work environment regardless of the industry. Their stockholders will be furious if the plant gets a NRC infraction causing a long downtime, thus reducing their profits greatly. If it turns out to be a problem at all of their plants, then I hope you don't have money invested in the energy sector because the entire industry will suffer. Generally, plants do pretty darn well with maintenance, but problems do happen. At the Shearon Harris plant outside of Raleigh, NC, there were quite a few problems years ago when the company was still Carolina Power and Light. Operators would press the wrong button when hearing an alarm (which happens about every 15 seconds as something needs to be bumped somewhere on an older instrumentation plant, which isn't the case with updated computer instrumentation mechanisms), causing an unplanned shutdown. The NRC told them to clean their act up, and since then it's had a pretty flawless record. So hopefully this won't cause too much harm to the industry, but it could if they let this kind of thing happen.
As far as reactor design goes, TMI was a overwhelming success as far as the containment structure went. On the other hand, their public relations was a abysmal failure, which is why people generally think that nuclear power may be unsafe. Had their incident response been better planned, it would not have snowballed into as big an event as it did. During and after the event, no radioactivity of any significance was released as a result of the safety mechanisms built into the design. So really, it was proof that even in the event of a loss of coolant accident, the design is still safe. After that incident in 1979, mind you that it was nearly 3 decades ago when nuclear power was in its adolescence, what other large failures have happened outside of fuel processing facilities? None.
A SCRAM is nothing on the safety of the plant, the safety is in the design of the redundant active and passive safety systems and containment. A SCRAM usually means operator error, which is why most plants are moving to digital instrumentation, control, and logging. Now I grant you that SCRAM's are not good events, as they cost the utility quite a bit of money and require NRC approval to restart after review of the events leading to the shutdown. With a reactor operating at nearly 1 GWe, that is quite a bit of revenue lost just in electricity production, not to mention the more expensive coal systems that have to be started to support the grid during the outage. So utilities don't want unplanned shutdowns, so their maintenance and operations records are usually spotless. That is why the industry as a whole have achieved a capacity factor over 90%, greater than any other type of electricity production. Utilities want clean safety records and to have their plants running as long as possible because it's more profitable that way. An ungreased valve at this plant was a maintenance error, and will probably result in that guy being fired (if he can be). I completely agree that redundancy in checking of work is necessary, and it is required in every plant so I'm not sure why they missed this (my guess is below). The risk of losing millions as opposed to hiring another maintenance worker at $50,000 per year is insignificant, so there really is no excuse for an ungreased valve.
My own opinion, after seeing how some plants get screwed when dealing with unionized workers, is that the maintenance crew had a few issues with workers taking sick days during the outage as a retaliation for something, resulting in fewer people to work. Instead of delaying the restart, they chose to over-task those fewer workers and try to make the scheduled restart, resulting in their loss of millions of dollars of revenue, not to mention the bad PR. Bad PR in the nuclear industry is something no utility can afford, so they'll likely be on the S-list of the NRC for a while. In my opinion, unions in this country should take a good hard look at how the auto workers signed their own pink slips by screwing the manufacturers into moving overseas and south of the border. Forcing your employers hand is only going to raise the risk of putting many people out of a job.
Refuelings can be performed faster these days because employees go through multiple dry-runs for the refueling and repairs before the system is brought off-line. This reduces exposure to maintenance crews and engineers. I can't fault them for going faster as the methods used across the entire industry are nearly identical and work over 99% of the time (103/104). Could it be a systematic problem at the plant? Maybe, as the number of tasks increase while the time each employee spends in the containment area decreases, you are bound to get a forgetful maintenance worker here and there; however, the goal of the dry-runs and checklists is to make sure that there are no forgetful maintenance workers. So this could be an issue with the administration there. If you have enough plants, the chances are that there will be issues like this at one of them at some point. The better part of this is that as these issues arise, the industry takes measures so that they don't happen again. Overall, the safety of nuclear plants in the US is spectacular.
Think back to grade school. You're sitting there taking a course that you didn't want to take but had to because the school chose it for you. You have no freedom of choice. I'm all for core curriculum as in math, science, language, and social studies, which is primarily what your first year of college is spent doing anyway. It does make you more balanced and gives a reasonable baseline. Students involved in AP or gifted programs have more options to study what they want, but it's those kids who aren't that need something to work towards. If you're interested in science and math, you have a science curriculum, if you're interested in business, then you have a mixture of economics and social studies. The idea of having targeted paths for students is great, in my opinion. For students that may change their minds, make the "major" be more like a minor. You take so many science classes for a science concentration, etc, while the core classes make up the real "major." In this case, the school seems to be making this a bit harder than it needs to be, but I think they're on the right track at least. High school is bad enough, so let the kids at least take classes that they want.
From an IT perspective, I completely understand Microsoft's shift towards having the home basic, home premium, business, enterprise, and ultimate versions. Why do you need media center capability in the office? And why would anyone at home need remote desktop? Well, I do and I'm sure a lot of other people do too. I don't want to be charged the Windows Tax on a new laptop and get an inferior product when compared to good ol' XP. I don't care if it has swoopy graphics, Beryl does that for free in Linux, but few retailers are willing to offer a no-OS/Linux option on a new machine for fear of upsetting the powers that be. I don't think I should have to pay the huge premium for the Ultimate version either, especially when it isn't offered by an OEM source to come pre-installed, but rather through the ridiculous upgrade program. Because I want to sit at the computer twice as long to get my desktop back if windows has a hiccup and won't boot. Lastly, why price the ultimate version at $399 MSRP? Are they banking on the idea that "gamers" or "power users" will have extra money to dish out for an OS that wastes their hardware resources? Or would that money be better spent on more ram or faster processor and an un-neutered copy of XP? I love Linux and have been a fan of Windows for years (since WFW 3.11), so I have no hatred of Windows (which may get this modded down), but their new sales plan is silly and annoying. I don't want to spend hundreds of dollars on a full version (I abhor upgrade versions and have since Windows 98), let alone select whether or not I want to go 64-bit with it at time of purchase if I don't want to wait/pay for MS to ship another DVD installer. I'll be staying away from Vista until the prices drop and problems start to disappear. Right now I have machines that all work, so why risk the headache?
Tests with liquid sodium have been very successful. In France, the Phenix/Superphenix designs have used liquid sodium for over 3 decades without incident. EBR-I and EBR-II used liquid sodium without problems (~1960's to 70's if I remember correctly). Oddly enough, the stainless steel (SS-304) assemblies came out of EBR-II after nearly 200 GWd of burnup looking brand new and shiny, which is kind of creepy when comparing that to spent assemblies from a LWR (light water reactor) after 33 to 60 GWd of burnup. The sodium cooled design is actually better in a LOCA (loss of coolant accident) than a traditional LWR. I agree there are some drawbacks to the sodium cooled design, such as keeping the coolant hot during fuel shuffles and potential water reactions in the secondary steam cycle, but as far as materials go, the sodium works much better with longer lasting burnups for fuel. Right now, from a fuels standpoint, we could manage the fuel in a LWR to burn up to nearly 100 GWd, which would use less fuel and reduce cost to utilities, but it's a materials limitation on the zircaloy cladding and assemblies. Water/steam at high temperatures is about the nastiest stuff imaginable when mixing with standard materials and it gets even worse as it is exposed to radiation (creates multiple free radicals during the neutron moderation process and gamma shielding). It literally eats away the cladding, giving a theoretical fuel lifetime (before failure and release of fission gasses into primary coolant) of ~70GWd/mton of fuel. Of course, that's without the safety factors added, which reduces to around 55GWd/mton (mton being metric tonne). There's an old NUREG (NRC regulations so should be a public document), number 1368 I think, that is an initial safety evaluation report on the viability of then GE/ANL designed ALMR (Advanced Liquid Metal Reactor, later termed PRISM and subsequently Super PRISM). If you want to see some of the nuclear side of it, there's a paper from ICONE-8 in 2002 on the design of the reactor giving some basic core specs but no fuel composition as that would be in the applied technology report that is kept as a trade secret. In any case, sodium cooling may seem counter-intuitive, but it's actually a very tested and mature technology.
The US designed sodium cooled reactor, SuperPRISM (formerly PRISM and ALMR), does create plutonium during a 150-180GWd burnup for both metal and oxide fuels. The question is which plutonium does it create. Only Pu-239 is useful in a bomb, while the other isotopes act primarily as fissionable poisons (low nu-bar value), but that's what you have in your driver fuel, so you have to separate that out anyway before fuel fabrication to make sure the isotopic concentrations are correct for startup. This requires a plutonium separating reprocessing step, which is exactly what the non-proliferation crowd doesn't want (IMHO, they really don't see that stable countries have no diversion, but refuse to leave their "treat every country equally" stance even though it's a long term economic and environmental benefit). The SuperPRISM design creates higher n- isotopes of plutonium. In fact, Pu-241 is the only produced in significant numbers that isn't further transmuted into Am-241, -242m, -243 or Cm-244. PUREX will probably not be used for commercial purposes (given the civilian reluctance to use certain military technologies), but rather some other modified form of the Japanese DIDPA or French DIAMEX solvent extraction processes. The disposal problems for spent LWR fuel have to go through the politics before anything can happen. After years of work, I have come to the conclusion that it's politicians who will make the decision based on whichever engineer has the flashiest powerpoint presentation and promise of pork for their state rather than an engineer who has an optimal and well constructed plan.
In the US, many jobs require using a computer every day for 8 hours while at the office. In the opinion of many that I know and have worked with, they don't see why they would want to sit in front of a computer for a few more hours when they get off work. This isn't a US vs rest of the world thing, it's apathy! Why sit in front of the computer typing away every night when you do it all day at work? That's what it comes down to for most of the baby boomer generation. For younger generations, it is probably borrowing their neighbor's wifi connection. For the 22% who said that they can't afford a computer, they didn't ask them if they could afford smoking either. So it's my opinion that the survey is somewhat incomplete and skews results in a certain way to make it look like much of the US is a backwards society when that's really not case. Some people just don't care about technology. Having other priorities and interests is not a bad thing.
For as much as I've been flying in the past few years, I've come into contact with cases of "Parents won't make their kid shut up rage," "Baby won't stop crying rage," or my favorite "that damn kid behind you won't stop kicking your seat and if you say anything else the flight attendant is going to ground the airport and have you arrested rage." I can only imagine where the "Teenaged girl won't stop saying 'like oh my god she did not!' while on the phone with each of her moron friends rage" might take us. I bet this is really a build up to airlines offering a new class of seating on the planes, "Quiet First Flass: where cell phones and children are not allowed."
I couldn't agree with you more. Just because something is correlated does not mean that they are actually related. Just because a country has cable means that children born and raised there have an elevated risk of mental disorders? What about the fact that cable is more prevalent in more affluent nations? I would assume that GDP be well correlated to a chance of autism. Why not look at amount of prenatal health care and draw a correlation from that. At a conference I heard a good argument that the increase in prenatal tampering (oversampling of ambiotic fluid, administering certain drugs to induce labor, excessive ultrasound images) in the US could be related to chances of childhood illnesses. Actual relations between administration of some oft prescribed drugs during a pregnancy have proven damaging to a child, but I'm sure TV is the real cause (a little sarcasm). You said it, this is scientific pornography.
I got my fiance stuck on linux after making her laptop run with kde on gentoo using the xcomposite module to make it look pretty (that and she thinks the penguin is cute). I've tried to explain to her why I have to compile everything, but she still says "Isn't it easier to just make one file that will run on all of them?" As much as I hate to say it, she's right, which is why windows has the advantage. As the variations on hardware are seemingly infinite, the possibility of compatibility is much larger when the executables aren't optimized for each individual platform, but rather run in a compatibility mode (rather -mcpu=i386). While it may not seem too hard to compile our systems, the average person doesn't want to. Instead, they just want it to work with minimal effort. So I figure that every normal user needs a personal tech support person to set up and support their linux box if it's going to take off the way most linux zealots think it should.
Ahhh nostalgia.... Here's my story, after I picked up a 286 computer with an EGA monitor and a whopping 210 megs of hard disk space off of a building company when their power flickered, I changed out the power supply and I was online shortly with a 2400 baud modem. I was 12 at the time (1993). I found the Southeastern Information Depot (SID) and downloaded a list of atlanta area BBS's (Hacker's Layer, the Brick Wahl, etc). After that, it was onto some hacking and warez BBS's. I stayed on those until internet services weren't pay by the minute. Well I didn't feel old until just now :-) Anyone else frequent Atlanta area BBS's back in the day?
There's quite a bit of money being dumped into enclosed nuclear power sources that can be deployed to third world countries or disaster areas. The basic design is a trailer type (surprisingly not designed in the South) self contained core/coolant/generator using a rankine regen cycle to output a few megawatts of electricity. Low power core, but enough to create viable heat using helium. Do I think it'll make its way off paper? Of course not, who would? But you're right, RTG's on earth are a thing of the past (save some older pacemakers and oceanic beacons).
That might be possible. (I am thinking about the radioactive materials used as power sources on some spacecraft.) Unfortunately we couldn't get a whole lot of energy out of the process (or get very much "wattage"), so no one would bother.
Not much wattage using an RTG? This is how our deep space satellites have worked for over 30 years when the initial lifetime was expected to be less than half that. When the temperature of space is around 3K, the temperature gradient between a large mass of plutonium can be large enough to generate more than enough electricity for modern electronics to function. A few kW can power a large amount of electronics.
We could also put it back in the reactor, and we do this already. Not all of the useful uranium is gone after the spent fuel rods are pulled from the reactor, and what is left can be reprocessed and used again. That can't be repeated forever, though.
Just about all of the "useful" uranium is gone. Initial enrichment is between 4 and 5% U-235 with the rest being U-238 which converts into a decent amount of plutonium and higher actinides. Fuel at discharge has around 1-1.5% U-235 since we can't run the reactors that long due to degradation of the cladding (structural material). Reprocessing doesn't exist to reuse uranium, it's to harvest plutonium and higher actinides which can be burned in a mixed oxide (MOX) core or a fast reactor (uses only transuranic fuel). You're right that the reprocessing cycle cannot last forever, but as it stands, we barely do it now. Much of the MOX fuel we use now is from an agreement with Russia to destroy weapons grade plutonium by burning it in commercial reactors. After that, MOX probably won't be used since it is expensive and somewhat unnecessary since the cost of fresh uranium is pretty darned cheap. Once the costs go up, then reprocessing will be back in vogue again. Another consideration to your comment that reprocessing cannot last forever, is that we don't use fast reactors. A fast reactor uses higher actinides in a much smaller core to produce a much smaller amount of energy, but it burns that pesky plutonium, thus increasing repository space for long lived fission products. Fast reactors can either burn, break even, and even produce plutonium (and anywhere in between). This lengthens the potential nuclear fuel cycle quite a bit, assuming that oil and coal disappear and other power forms remain as weak as they are. But right now, it's economics and politics as to why this isn't done, because technology is there.
The current solution is waste vitrification where we seal the spent fuel into a borated glass mixture. Boron absorbs decay neutrons from the transuranics, so criticality issues are avoided when lumping lots of actinides. The problem is heat. Fission product heat loads are effectively gone within 200 years. The current idea of letting the waste sit in a spent fuel pool for 30 years (30 years is the usual cutoff for short/long lived fission produts), is the best and only option we have if we don't want to fill the maximum heat capacity of the repository within 20 years. The repository as it stands can fit as much mass as was removed from it to create the tunnels and storage area. Since there are structural materials and criticality checks all through there, the masses are somewhat spread out, but still rather close together until you look at the decay heat. After the first 30 years, the integral heat load is all actinides. The heat doesn't drop off for thousands upon thousands of years. In a mountain with passive cooling (meaning natural conduction through rock, not a good conductor), an integral heat load that is too high can raise the temperature of the repository to dangerous levels. To keep the temperature down, the waste is spread out, which decreases the actual mass capacity by far. Any reprocessing can raise the capacity of the repository from a factor of 4 to around 80 when removing the actinides from the long and short lived FP's. The reality hasn't changed one bit in the past 30 years, reprocessing is still not going to happen until the cost of uranium increases to the point where it's more economical to reprocess than to purchase new fuel. Eventhough Carter tossed aside the american reprocessing efforts, the main factor for why it hasn't come back is pure economics.
To cite a good presentation at a conference:
Preston, Jeff. "The Influence of Fuel Cycle and Spent Fuel Characteristics on Repository Heat Loads." Transactions of the American Nuclear Society, Vol 94. 2006.
It is pretty easy to shield using water, since that's how spent fuel is stored after discharge from commercial plants until it's cool enough to move to dry storage (temperature cool, not radiation). Dry storage works just fine once the thermal loadings are low enough. Casks such as this are present at nearly every nuclear facility that hasn't moved fuel offsite.
My question about doing this on a large scale, is how are you going to keep this much material cool enough to reduce the half life assuming that this works in the first place? Alpha emission of transuranics has around 6.5 MeV of energy per particle, which translates into a large amount of heat for not so large amounts of material. The coolant material to waste ratio would be enormous! Also, the refrigerant energy to do this would probably render the entire process even more inefficient than the current idea of reprocessing (remember that reprocessing has lots of particularly nasty chemicals associated in large quantities). Since alpha emitting isotopes are neutron rich, meaning they are either fissile or fissionable, they can be used as fuel. Why destroy fuel when you can burn it? At worst, continue MOX reprocessing as is currently done. At best, fuel some RTG's for space exploration. In my mind, this type of research is "neat" at best, but if the purpose is trying to force schrodinger's cat back into the bag, they can forget it now that global warming is becoming a hot issue with nuclear power the sole possibility for continuing the current growth rate of electricity demand (way too many puns there, I apologize).
For learning purposes, you can save a lot of headaches by setting up a VWware linux setup and do snapshots so you can roll back when you do something that screws up the system (had a guy try to set up an NFS server and ended up formatting the /usr directory, how that happened, I don't know). It's also quite nice as a testing platform since the vmplayer is free. What that means, is if you have a room full of computers that never get used (as I do in my undergraduate student's computer lab), I can run the vmplayer over windows as my user and let the students login separately. This is also kinda nice so that I can do a scripted active hosts file that updates the cluster setup so that I can have 2 or 20 machines without touching a conf file myself. Surprisingly, there isn't much cpu power lost when running the VM over windows, just network lag since I do the NAT option so I don't have to register new IP's. I run MPI to drive a distributed version of MCNP (neutron transport code) on my personal cluster (Rocketcalc with extra OTS PC's as extra nodes) and do the VM for fun/testing. Other than that, look at the Gentoo HPC howto's, MPI/PVM/LAM manuals, and try to plan out your cluster before starting. It's much easier to get things to work when you know what you're trying to do beforehand than to bumble through it and say "wouldn't it be cool if..."
Not encrypting the password hashes seems more like an ethical question for a sysadmin. First off, why even put yourself in the position to potentially have access to your user's personal info? I say this will full knowledge that there are people out there who use the same password for every single site they use thinking it's secure (no, I don't mean you mom). So even if a sysadmin doesn't do this with unethical intentions, he's still leaving his users info out in the open should a more unscrupulous fellow gain access to the system. At least hash with something as a deterrant. Best case scenario the person who breaks in will have to waste time cracking with john. Say myspace or facebook did this and the entire userbase had their passwords taken. How many college students probably use the same password on there that they do everywhere else? It would be a nightmare for some and a wet dream for spammers, carders, and others. There's just no reason that with all the hashing API's and OSS projects out there, that a sysadmin would be lazy enough not to encrypt the password list/database.
Cancer gene is misleading? That's where cancer comes from! Radiation and chemical effects of cancer change are present in the restructuring of DNA strands during the dna replication phases of cellular reproduction. That's why you have multiple treatments of x-rays for a cancer treatment, to kill cells that were in between reproductive cycles. And what rubber band is stretched? The replication sequence follows a straight path on the individual rna strands. It doesn't look at multiple locations on different strands before deciding to create a protein. If they created a stop codon that blocks unrestricted, accelerated cellular reproduction (cancer), then great. But if this affects the "soul gene," then I think James Brown might sue.
You're referring to low level waste. Water around a spent fuel pool is monitored and deionized constantly to keep it clean of contaminants that might get irradiated and create a health hazard, so there isn't a lot of associated activity with it, which is why it is called low level waste. Low level waste is sent to a processing/storage facility where it sits until the activity monitors drop to EPA's (or equivalent's) allowable levels, time scale less than 5 years usually. After that the stuff can be thrown in the garbage or recycled. Depending on the type of reactor, the water never leaves the core (PWR) or can leave the core (BWR). In the case that it does leave the core, the big issues are tritium (12 yr hl), nitrogen-16 (~14 minutes), and a few other short lived nuclides. Sites actively monitor material outputs, such as water, to make sure tritium levels are not exceeding the EPA limits. In the case of a few BWR's that have exceeded the limits, they have to go back and figure out where and how to fix it so that it doesn't happen. In any case, tritium has a biological half life of less than 5 days, so humans get a very tiny dose ( 1mSv) from a few mCi ingested. Other material such as structural supports for fuel bundles and cladding are stored with the fuel in the pool (of course) and in the dry storage after enough time has elapsed. The long term view, for Yucca (or any other geologic repository for that matter), is to store all of the material in a vitrified (borated glass) form. This means they would break all the waste down in either an acid or crusher and mix with molten glass to add a neutron absorbing, solid material around the waste to prevent any criticality accidents since we can't fight off the stigma that plutonium is evil. With this kind of long term waste storage, it would be a few thousand years before the radioactivity levels drop to that of natural uranium (cutoff for safe material is uranium ore). With large scale reprocessing using PUREX (Pu-Uranium-Extraction) and a few fast reactors the long term storage activity level drops from many thousands of years to around 300 years, if we do it right that is. That help?
From a dose assessment aspect, this is no surprise at all. The initial release was horrible on the wildlife populations; however, take a base assumption that biological effects of radiation differ for all species. As the Russell's found out in their "mega mouse" experiment at Oak Ridge, what is harmful to mice isn't necessarily harmful to humans and same thing with bears, deer, pigs, birds, etc. The initial release consisted largely of I-131, Cs-134/7, Sr-90, tritium, some actinides, and some other shorter lived fission products that primarily followed a modified gaussian plume model for the initial distribution to the air/soil. The I-131 was a huge dose at first, but with an 8 day half life, it was gone after a few weeks. Also keep in mind that not all species have large iodine uptake to the thyroid as do humans, so the initial release of I-131 would not have affected local populations as much in the first few weeks while the I-131 was still present. The Cs-134 and tritium is gone as well, and the Cs-137 will be around for another 100 years if the initial estimates were correct. Cross sectional species tests for osteosarcoma should be done to check for effects of Sr-90 in the bone to see how healthy the animals truly are (leukemia and blood disorders could be present), but even Sr-90 drops straight to the water table and I doubt these animals are drinking out of wells so their water supply is relatively clean compared to what a human would expect there. The external dose from actinide contamination in soil is extremely low as well, not as low as uranium ore, obviously, which is the standard, but still low enough not to cause a problem to wildlife since the uptake factor to plants is very low for actinides since they're so massive and the chemistry doesn't allow much at all. That said, leaves coated with dust from the fallout would be a large addition to the soil/vegetable ingestion dose for animals, but after a few generations of plants and many rinses in rain would render the leaves relatively clean of actinides. Nature finding a way to survive isn't surprising at all.