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Samurai-Sword Maker May Cool Nuclear Revival
NobleSavage sends a story from Bloomberg about Japan Steel Works Ltd., a company that still makes Samurai swords, and how it may control the fate of the global nuclear-energy renaissance. "There stands the only plant in the world, a survivor of Allied bombing in World War II, capable of producing the central part of a nuclear reactor's containment vessel in a single piece, reducing the risk of a radiation leak. Utilities that won't need the equipment for years are making $100 million down payments now on components Japan Steel makes from 600-ton ingots. Each year the Tokyo-based company can turn out just four of the steel forgings that contain the radioactivity in a nuclear reactor. Even after it doubles capacity in the next two years, there won't be enough production to meet building plans."
Swords are not exactly a growth industry. If they are genuine samurai swords, they can't be exported, and if they aren't, they are practically worthless (about the same price as the cheap Spanish ones they sell on QVC).
The 5 year gap is important because during that 5 years, they'd expect to be able to increase capacity while other forgers would still be getting started.
However, the problem is China and its vast natural resources. Japan, unfortunately doesn't have the natural resources to do this cheaply for very long. As China (and I suppose Korea) get their furnaces running, the customers will start looking to cheaper pastures.
Depleted uranium is still bad for you. See this.
This article is from 2006. Surely there's more recent news, even about this topic?
New nuclear build is not going to grind to a halt because this plant can't keep up.
"Physics is to math as sex is to masturbation." -R. Feynman
Yeah, I read that article. But if you honestly think that I was replying to an earnest post with anything but jest, you should really find a new sense of humor. Also, having a density of about 19.1g/cm3, it tends to be just over twice as heavy as sword steel (at 7.8g/cm3). Your 2kg sword would be 4.8kg and tire you and your four arms out quite nicely.
This sig isn't original enough, it's time to come up with something witty...
The wiki article you linked states itself that DU is less toxic then many other common materials like arsenic. The statistical evidence linking birth defects to soldiers is dubious at best. This is pretty much a case of DHMO-itis, i.e., irrational fear over something not inherently dangerous. DU, like DHMO, are feared because of their mystique (in the case of DHMO-a ominous sounding acronym).
And the reason why the CANDU was designed was because it runs on natural, unenriched uranium. It had nothing to do with the design of the pressure vessel. When the first CANDU's were being built, the US was still manufacturing PWR pressure vessels and there was no problem in that area.
The problem here is not wanting to stick with currently proven designs, but the hideous cost of certifying a new design. It is so expensive to re-certify a project after a design change people really don't want to do it often.
The certification process probably makes the design safer, but it also disincentives innovation in ways that would horrify someone used to the rapid pace of consumer electronics.
On the other hand, the kind of reliability standards we see on consumer electronics would horrify me if they ever happened be applied to a nuclear facility or an airplane.
http://www.dieblinkenlights.com
I think the article confuses the reactor vessel with the containment vessel.
A reactor vessel is a large-room-sized steel vessel, that holds the fuel and steam transfer pipes and so forth and is subjected to huge internal pressures in normal operation.
A containment vessel is the building-sized concrete structure that gives many reactors buildings their impressive dome shape. It is only important in the case of an accident, when it might be subjected to pressures on the order of an atmosphere or so. It is intended to hold in or contain any radioactive materials released after an accident has occurred.
Interestingly enough, in light of his demonization by anti-nuclear factions, it was Edward Teller who was largely responsible for insisting on containment vessels, a nice simple brute-force protection measure.
Every reactor has a reactor vessel, but not all reactors have containment vessels. Some reactors, such as Chernobyl, and, in the United States, GE boiling-water reactors such as the one in Plymouth, Massachusetts have very ordinary-looking block-like buildings rather than containment domes. These reactors are designed to "suppress" pressure in an accident rather than "contain" it, by the use of engineered mechanisms that open valves at the right time and direct steam through big tanks of water, cooling it down and condensing it.
"How to Do Nothing," kids activities, back in print!
The CANDU was designed with two main differences: Heavy Water Moderator -Lets you use natural uranium -Safer than graphite Pressure Tube Design -To avoid needing heavy manufacturing capabilities -This has nothing to do with ability to use natural uranium The Caladria is indeed big but does not need to be forged in one piece (or be as thick) as it does not have to hold in a significant amount of pressure (unlike the pressure vessel, naturally).
That's incorrect. The US Military admitted there were 'some unknown dangers' associated with DU after Dr. Doug Rokke (US Army Physicist) got cancer and is suffering numerous other ill effects from radiation poisoning whilst leading efforts to clean up the radiation after the first Iraq war. He also has explained that the US Military actively suppressed a WHO study which showed DU has the same effects as normal uranium on the human body. I only know because his brother, General Irving Rokke was the Dean of my college and I got to speak with him. I also learned about how the US and UK have been pressed about the issue numerous times in the UN and have used their comfy chairs on the UN Security Council to veto any sort of punitive action.
As I understand it CANDU reactors don't even use a pressure vessel as such, but instead uses an assembly of pressurized tubes. One for each fuel bundle.
True. You get complete separation of the coolant and the moderator. Most reactor designs don't do that.
This design was chosen precisely because it eliminated the need for this type of technological bottleneck and it is still in use today.
No, it was designed for very high safety, and (more importantly) that it can run on naturally occurring uranium without isotope enrichment. There are 2 kinds of uranium, U-238 and U-235. Only the U-235 is fissionable, and it naturally occurs about 0.7% of the time. Most nuclear reactor designs need enrichment to around 2-3% to function. To build bombs, you need to enrich to over 90%.
Of course, the same enrichment technology to go to 3% can be used to go to 90%. What is stopping you from enriching further? Nothing. That is why so many people are concerned about Iranian claims of only enriching uranium for nuclear reactors.
If your country is planning to secretly develop nuclear bombs under the cover of peaceful nuclear technology, CANDU is not the way to go, because you don't need enrichment.
Strangely enough, the CANDU reactor doesn't do so well with international sales.
Exactly right. The reason that CANDU uses pressurized tubes rather than a large reactor vessel is because Canada lacks the ability to manufacture a large vessel. It hasn't been too much of an issue though because Canada has built enough CANDU reactors for a peak of 100+ TWh of power, and currently around 85 TWh of power
The outer Calandria is a Steel Vessel with a low pressure rating -- rupture disks that blow at 35 kPa or so. It is about 10 meters in diameter. It is full of heavily tritiated heavy water, so it is well sealed for personnel safety. The Calandria is on its side, so fuel is loaded from one side, and pushed out the other.
/in Candu land
There are 380 (or so, depending on model) pressure tubes (6" diameter?) made of Zirconium/Niobium Alloy that will withstand the 13 MPa and contain 12 (again, or so) fuel bundles that can be changed out online.
A straight pressure tube is much easier to make, but the alloys are a pain to work with, and the QA/QC for Nuclear class 1 materials are very rigorous.
The JSW's containment vessel is a one-piece unit. Containment vessels made from more than one piece can (and are) manufactured all over the world. The advantage of the one-piece unit is that it has no seems, preventing radiation leaks. There are other methods of controlling radiation for the multiple-piece CVs.
It is dangerous to be right when the government is wrong.
So.. it's less toxic than one of the world's most famous deadly poisons
That's really reassuring.
ADVENTURERS! - ANTIHERO FOR HIRE - CARDMASTER CONFLICT
The newer designs (eg. breeder reactors) can run essentially for forever and do not produce much waste at all (they eat their own waste in fact).
Depleated Uranium would have the same effect as lead poisoning, but at least lead is harder to get into the air as it is more ductile and lead bullets tend to break into a few small pieces and deform, whereas Uranium is harder and will shatter causing smaller bits to flake off and become airborne.
We are talkign the "chemical" properties of Uranium, not the radioactive properties, so many people think nuclear when they think of uranium, they forget uranium has chemical properties and can form checmical compounds like every other element.
The main problem with Depleted Uranium is heavy metal poisoning. We should use Bismuth instead that way we shoot someone in their gut and we cure their stomach ache, but they die of blood loss, Bismuth is the main ingredient of Pepto-Bismal and is one of the few heavy metals that is non-toxic in it's metalic form. It is also quite dense and can be used like lead, but again it is brittle like Uranium.
Tsukasa: All I really want, is to be left alone...
According to this, Russia can produce two reactor pressure vessel forgings per year, with plans to double by 2011.
But all this delay in "evolutionary" boiling water reactors could be good news for pebble bed reactors. This Blog has a handy summary of the advantages and disadvantages of pebble beds. Last November, Westinghouse bought a pebble bed company called IST Nuclear. Some nice diagrams.
--- Often in error; never in doubt!
Have you ever tried to destroy a nice big steel vessel inside of a 3 foot steel reinforced concrete containment building?
From the wikipedia article...
In 1988, Sandia National Laboratories conducted a test of slamming a jet fighter into a large concrete block at 481 miles per hour (775 km/h) [10][11]. The airplane left only a 2.5-inch deep gouge in the concrete. Although the block was not constructed like a containment building missile shield, it was not anchored, etc., the results were considered indicative. A subsequent study by EPRI, the Electric Power Research Institute, concluded that commercial airliners did not pose a danger. [12]
The Turkey Point Nuclear Generating Station was hit directly by Hurricane Andrew in 1992. Turkey Point has two fossil fuel units and two nuclear units. Over $90 million of damage was done, largely to a water tank and to a smokestack of one of the fossil-fueled units on-site, but the containment buildings were undamaged [13][14].
http://en.wikipedia.org/wiki/Containment_building
I can think of far easier targets...
Nuclear reactor pressure vessels are a real problem. Most of the larger ones are in fact built up from welded sections. This isn't an easy welding job, and inspection of welds is a big headache. Several Japanese nuclear plants have had problems with cracks in pressure vessel welds, although in internal reactor components welded to the shell, not the shell itself. So making the pressure vessel and its internal support structures from one big forging makes a better product.
The environment of a reactor pressure vessel is tough. First, there's "embrittlement". Neutrons are constantly blasting apart the atoms in the pressure vessel, and over a period of years, this structural damage adds up. Then there's corrosion. There have been major corrosion problems requiring reactor shutdowns from carbon dioxide and boric acid corrosion inside the pressure vessel. Remember, this is a steam pressure vessel; at steam temperatures and pressures, minor corrosive effects at room temperature become big problems.
High quality welding of thick steel sections is a tough problem. Many approaches have been tried. The general idea is to make a V-shaped notch and fill it in during the welding process. Doing this in a way that's no weaker than the surrounding material is hard. Electric arc welding under an inert gas is the usual approach. Electron beam welding and laser welding have been tried. Then there's the problem of approach angle - welding on a vertical surface is not easy. Quality control requires X-rays, ultrasonic tests, and regulators that aren't corrupt.
So there's much to be said for building the pressure vessel as one big forging. Of course, then there's the problem of delivering a 550-ton object to the job site. There are companies that can do that, if you can find them a clear path from a seaport.
Sword making technology is relevant to the making of big forgings. Swords are built-up forgings. This is unusual in modern metalworking; most modern forged objects, like tools, are banged out in one piece by equipment much larger than the thing being manufactured. Big pressure vessels are built-up forgings; the scale requires it. In Japan, it's considered a good doctoral thesis in metallurgy to improve on sword making technology. So smart people are still thinking about the technology of built-up forgings. Nobody else bothers much.
Here's a US NRC fact sheet. on pressure vessels, and a similar European document.
Of course depleted uranium and "regular" uranium have the same effect on the body - they are the SAME thing. It would be like saying that there is this regular Oxygen that is different from the special Oxygen-16 and Oxygen-18. Chemically, they are identical, just like Uranium vs. U-235 vs. U-238.
Furthermore, "regular" Uranium and "depleted" Uranium and "enriched" Uranium have nothing to do with it being Uranium or not. It only has to do with Uranium-235 abundance. Regular just has under 1% of the U-235 and the depleted has "less". But it is still Uranium!!! Heck, the two types have virtually identical radioactivity (depleted vs. natural)
And chemically, they pose the same problems because they have identical chemical properties (because both are Uranium!)
Anyone saying that DU is safe is full of *shit*. We all know that Uranium mining and smelting can be hazardous tasks. Spreading it around in dust form and saying the opposite in light of the truth and past experiences is criminal.