Task Force Conclusions The lessons learned task force (LLTF) concluded that the DBNPS VHP nozzle leakage and RPV head degradation event was preventable. While this review was primarily introspective, this question could not be answered without considering industry activities and DBNPS’s per- formance. At DBNPS, early indications of RPV corrosion were missed such as radiation element system filters being clogged by boric acid and corrosion fines, the build up of boric acid deposits on containment air cooler fins and large amounts of boric acid deposits on the RPV head. The task force concluded that the event was not prevented because: (1) the NRC, DBNPS, and the nuclear industry failed to adequately review, assess, and follow-up on relevant operating experience, (2) DBNPS failed to assure that plant safety issues received appropriate attention, and (3) the NRC failed to integrate known or available information into its assessments of DBNPS’s safety performance. Furthermore, an NRC investigation concluded that DBNPS did not adequately execute the boric acid corrosion control program in response to an NRC Generic Communication, and the NRC did not adequately review the industry implementation of long term commitments, such as the commitment to maintain a boric acid corrosion control program.
The problem is not the age of the reactor, but proper implementation of safety reviews. I hope this will be changed.
It's that easy. Why do people keep making prescriptions that would affect absolutely everyone, just because they personally don't like something?
If you want a small phone, buy one, period.
Anything else is just saying that your taste and your desires are more important than anybody else's. That's just not true and sure sign of pure arrogance.
The similarity ends right *after* the weight. This kit car also weighs 200kg. The engine is 600W and battery is a 1kWh affair (nominal - 36V, 38Ah).
The problem seems to be that everyone is using car technology to build electric vehicles - when you should in fact think of it as a 4-wheeled e-bike with minimum weight. I see no reason why, given the performance, such a kit car should weigh any more than 40-60kg (minus the batteries and driving).
Damnit, even the worst fearmongers tell us that temperatures will rise by 1 degree per 20 years. Even ignoring the fact that this kind of temperature rise is insignificant in terms of what we're talking about, that's decades or centuries to replace infrastructure.
Instead of worrying about asphalt on streets, I'm worring about brains already having melted in one-too-many climate change activists demonstration.
Just having access to books when you need it is reason enough to have tablets or netbooks in schools. Instead of talking about Adam Smith, you can just read his books. Instead of handing out 20-30 thousand page books to all the pupils in the class, all you need is have them download a 1-2MB file. Fully searchable. And that's just one example.
A single tablet can fit all books you'll ever need in school instantly accessible at any time.
Even if tablets do absolutely nothing in the way of improving education in any other way, that's reason enough.
What you're saying amounts to saying how many trees you can fell in a forest using nothing more than axes. Hint: It's a lot more than the number of trees growing back in the same time.
If you don't care about sustainabliity then say so.
Where sustainability is concerned, you must not extract more energy than is coming back from the interior of the earth - completely independent on whether or not you could extract more than that - because you can.
Actually, the inaccessible land is forest for the most part and the Japanese are quite proud of it and happen to like their landscape.
I also doubt that just putting solar on all roofs is enough. (Japan has multistory houses and rather dense urban settlements. Quite unlike american suburbs that are ideally suited for solar, but for all the wrong reasons - namely extremely high energy needs for driving, heating, air conditioning etc.) And roofing all roads is not really an option. Some of them perhaps (and parking lots of course!) , but I couldn't imaging not seeing the sky while traveling.
Then try an average heat flux of 100mW/m^2 for the whole country (which is roughly accurate). If you take out more than that, you simply cool down the rocks - fossil heat if you will. The heat flux is what you can take out sustainably.
An efficiency of 20% is actually too high for geothermal (most geothermal power stations have efficiencies well below 10%), but, whatever. You'll get 20mW/m^2 of electricity. 50.000km^2 per GW. For a country the size of Japan that's no more than 8 GW of electricity - and that's being extremely generous as you would have to install pipes below the whole of the country and the efficiency is too high.
That area is far too small. Even at 10W/m^2 you'd only get 1.28 GW on that area.
You forget about the unavoidable gaps you need between the solar panels to avoid casting a shadow on neighbouring panels. On houses that is no problem, because the shadow is where the other half of the house is and you don't count the area of the other half of the house. But when you try to saturate an area with solar panels that cannot be ignored.
The solar park i linked to delivers an annual average of 4W/m^2. That's 60MW peak, 6MW average, 160 hectars of land. That's the real numbers. Since Japan is further south, I used 6W/m^2.
In fact reactor #6, while shut down at the time of the tsunami, was the only reactor that still had a functioning power supply after the tsunami. It was the only BWR5 design (#1 was a BWR3, #2 to #5 were BWR4) - unlike the others, it had three separate subdivisions each capable of cooling the reactor in the event of a power outage. Redundancy works. Just as in the Tokai, Fukushima Daini and Onagawa nuclear power plants that were also hit by the tsunami.
However, neither TEPCO nor the Japanese Government should be spared any criticism for failing to upgrade the power plants. Hydrogen explosions were a known problem in those plants and could be prevented for a very modest sum of a few million dollar per reactor. Filtered containment vents were also implemented all over europe, Japan was attending the Paris conference on filtered containment vents in June 1988 and the only nation not to issue any official statement at all about them or initiate any studies on the problem.
Until 2011 I thought Japan was basically a modern country with decent safety standards - now I know better.
If you want to replace just Fukushima Daiichi with solar power, you'd have to blanket the whole evacuation zone with one huge solar power plant like that one. (Notice the incredible environmental friendliness of solar power in that place!). But in fact, you'll lose about half of that energy due to storage issues or inefficiency.
In order to replace all Japanese nuclear power plants with solar power, you need ten of those power plants - if you ignore storage losses.
Do the math. 40% of of the energy for 0.25% of the population means 0.1% of the total energy use of Japan if Japan used as much geothermal as Iceland.
No, Japan doesn't have enough geothermal.
Geothermal energy is an extremely limited resource, even though most people claim otherwise. New Zealand had to scale down several geothermal powerstations because they took too much heat from the reservoirs. Japan has about 30 times as many people as New Zealand. And New Zealand (itself the place of the largest volcanic eruption of the last 2500 years or so) only gets 10% of its energy from geothermal.
Well, if they'd design it now, they'd probably put an Allwinner A10 SoC into it. But that was only available at the end of last year. (With actual products shipping this year.) Pretty good graphics and a Cortex A8 with up to 1.5GHz for $7.
Most of it is rocket fuel to get from the transitionary orbit (GTO), where the satellite is released, to the geostationary orbit (GSO). The GTO is a highly elliptical orbit with the highest point already near the geostationary requirements and the lowest point some 300km above the surface. (This means that the upper stage of the rocket will eventually be slowed down and burn up in the atmosphere, otherwise it would stay in orbit and add to the waste.) This fuel is on the order of a third or a half the weight of the satellite.
That's why there is a) considerable interest in doing this with much more efficient ion engines and b) a huge amount of head shaking over why this hasn't already been done a decade ago.
Well, actually the Falcon 5 (way back when) has always been meant as a stepping stone to the Falcon 9 and eventually Falcon 9 Heavy. (That was before they developed the Merlin 1D and started referring to it as Falcon Heavy, increasing its mass and payload by about 50%.)
However, Falcon 5 was abandoned, most likely for lack of customers. It was a rather bold move to concentrate on building the Falcon 9 and the Dragon right away, but obviously justified in retrospect. (I thought they'd need it to practice, especially after the first three launches of Falcon 1 failed.)
All the Falcon X plans are a very different matter - those are not plans, but were referred to as "brainstorming ideas". (Which may be, and very often are, silly and unrealistic.) However, if Elon wants to go to Mars, he'd better build bigger rockets rather than smaller ones.
Slashdot Mirror
Quote:
Task Force Conclusions
The lessons learned task force (LLTF) concluded that the DBNPS VHP
nozzle leakage and RPV head degradation event was preventable. While
this review was primarily introspective, this question could not be
answered without considering industry activities and DBNPS’s per-
formance. At DBNPS, early indications of RPV corrosion were missed
such as radiation element system filters being clogged by boric acid and
corrosion fines, the build up of boric acid deposits on containment air
cooler fins and large amounts of boric acid deposits on the RPV head.
The task force concluded that the event was not prevented because: (1)
the NRC, DBNPS, and the nuclear industry failed to adequately review,
assess, and follow-up on relevant operating experience, (2) DBNPS
failed to assure that plant safety issues received appropriate attention,
and (3) the NRC failed to integrate known or available information into
its assessments of DBNPS’s safety performance. Furthermore, an NRC
investigation concluded that DBNPS did not adequately execute the
boric acid corrosion control program in response to an NRC Generic
Communication, and the NRC did not adequately review the industry
implementation of long term commitments, such as the commitment to
maintain a boric acid corrosion control program.
The problem is not the age of the reactor, but proper implementation of safety reviews. I hope this will be changed.
It's that easy. Why do people keep making prescriptions that would affect absolutely everyone, just because they personally don't like something?
If you want a small phone, buy one, period.
Anything else is just saying that your taste and your desires are more important than anybody else's. That's just not true and sure sign of pure arrogance.
Driver, not driving ...
The similarity ends right *after* the weight. This kit car also weighs 200kg. The engine is 600W and battery is a 1kWh affair (nominal - 36V, 38Ah).
The problem seems to be that everyone is using car technology to build electric vehicles - when you should in fact think of it as a 4-wheeled e-bike with minimum weight. I see no reason why, given the performance, such a kit car should weigh any more than 40-60kg (minus the batteries and driving).
Damnit, even the worst fearmongers tell us that temperatures will rise by 1 degree per 20 years. Even ignoring the fact that this kind of temperature rise is insignificant in terms of what we're talking about, that's decades or centuries to replace infrastructure.
Instead of worrying about asphalt on streets, I'm worring about brains already having melted in one-too-many climate change activists demonstration.
Just having access to books when you need it is reason enough to have tablets or netbooks in schools. Instead of talking about Adam Smith, you can just read his books. Instead of handing out 20-30 thousand page books to all the pupils in the class, all you need is have them download a 1-2MB file. Fully searchable. And that's just one example.
A single tablet can fit all books you'll ever need in school instantly accessible at any time.
Even if tablets do absolutely nothing in the way of improving education in any other way, that's reason enough.
> And they stole all our rocket secrets in the 90's.
Says an American - from a country whose most used rocket is running on a Russian RD-180 engine.
For successful technology, reality must take precedence over public relations, for nature cannot be fooled.
No matter who you are, that's true for any technology.
... in the process.
This is neither the first nor in any way exceptional, but in every single instance, it is a disgrace!
You might also want to refer to this map to see that 100mW/m^2 is realistic.
I prefer real numbers. You might want to start with the geothermal map of Japan, instead of waving your hands about impressively.
What you're saying amounts to saying how many trees you can fell in a forest using nothing more than axes. Hint: It's a lot more than the number of trees growing back in the same time.
If you don't care about sustainabliity then say so.
Where sustainability is concerned, you must not extract more energy than is coming back from the interior of the earth - completely independent on whether or not you could extract more than that - because you can.
The area is supposed to be heath land? In the middle of a forest?
Actually, the inaccessible land is forest for the most part and the Japanese are quite proud of it and happen to like their landscape.
I also doubt that just putting solar on all roofs is enough. (Japan has multistory houses and rather dense urban settlements. Quite unlike american suburbs that are ideally suited for solar, but for all the wrong reasons - namely extremely high energy needs for driving, heating, air conditioning etc.) And roofing all roads is not really an option. Some of them perhaps (and parking lots of course!) , but I couldn't imaging not seeing the sky while traveling.
Then try an average heat flux of 100mW/m^2 for the whole country (which is roughly accurate). If you take out more than that, you simply cool down the rocks - fossil heat if you will. The heat flux is what you can take out sustainably.
An efficiency of 20% is actually too high for geothermal (most geothermal power stations have efficiencies well below 10%), but, whatever. You'll get 20mW/m^2 of electricity. 50.000km^2 per GW. For a country the size of Japan that's no more than 8 GW of electricity - and that's being extremely generous as you would have to install pipes below the whole of the country and the efficiency is too high.
Real enough?
Ahh, I see your mistake:
1ha = 0.01 km^2
160ha = 1.6 km^2
That area is far too small. Even at 10W/m^2 you'd only get 1.28 GW on that area.
You forget about the unavoidable gaps you need between the solar panels to avoid casting a shadow on neighbouring panels. On houses that is no problem, because the shadow is where the other half of the house is and you don't count the area of the other half of the house. But when you try to saturate an area with solar panels that cannot be ignored.
The same thing happens everywhere? How come, then, that most european countries did in fact upgrade their safety systems?
The solar park i linked to delivers an annual average of 4W/m^2. That's 60MW peak, 6MW average, 160 hectars of land. That's the real numbers. Since Japan is further south, I used 6W/m^2.
In fact reactor #6, while shut down at the time of the tsunami, was the only reactor that still had a functioning power supply after the tsunami. It was the only BWR5 design (#1 was a BWR3, #2 to #5 were BWR4) - unlike the others, it had three separate subdivisions each capable of cooling the reactor in the event of a power outage. Redundancy works. Just as in the Tokai, Fukushima Daini and Onagawa nuclear power plants that were also hit by the tsunami.
However, neither TEPCO nor the Japanese Government should be spared any criticism for failing to upgrade the power plants. Hydrogen explosions were a known problem in those plants and could be prevented for a very modest sum of a few million dollar per reactor. Filtered containment vents were also implemented all over europe, Japan was attending the Paris conference on filtered containment vents in June 1988 and the only nation not to issue any official statement at all about them or initiate any studies on the problem.
Until 2011 I thought Japan was basically a modern country with decent safety standards - now I know better.
If you want to replace just Fukushima Daiichi with solar power, you'd have to blanket the whole evacuation zone with one huge solar power plant like that one. (Notice the incredible environmental friendliness of solar power in that place!). But in fact, you'll lose about half of that energy due to storage issues or inefficiency.
In order to replace all Japanese nuclear power plants with solar power, you need ten of those power plants - if you ignore storage losses.
Do the math. 40% of of the energy for 0.25% of the population means 0.1% of the total energy use of Japan if Japan used as much geothermal as Iceland.
No, Japan doesn't have enough geothermal.
Geothermal energy is an extremely limited resource, even though most people claim otherwise. New Zealand had to scale down several geothermal powerstations because they took too much heat from the reservoirs. Japan has about 30 times as many people as New Zealand. And New Zealand (itself the place of the largest volcanic eruption of the last 2500 years or so) only gets 10% of its energy from geothermal.
Well, if they'd design it now, they'd probably put an Allwinner A10 SoC into it. But that was only available at the end of last year. (With actual products shipping this year.) Pretty good graphics and a Cortex A8 with up to 1.5GHz for $7.
Most of it is rocket fuel to get from the transitionary orbit (GTO), where the satellite is released, to the geostationary orbit (GSO). The GTO is a highly elliptical orbit with the highest point already near the geostationary requirements and the lowest point some 300km above the surface. (This means that the upper stage of the rocket will eventually be slowed down and burn up in the atmosphere, otherwise it would stay in orbit and add to the waste.) This fuel is on the order of a third or a half the weight of the satellite.
That's why there is a) considerable interest in doing this with much more efficient ion engines and b) a huge amount of head shaking over why this hasn't already been done a decade ago.
Well, actually the Falcon 5 (way back when) has always been meant as a stepping stone to the Falcon 9 and eventually Falcon 9 Heavy. (That was before they developed the Merlin 1D and started referring to it as Falcon Heavy, increasing its mass and payload by about 50%.)
However, Falcon 5 was abandoned, most likely for lack of customers. It was a rather bold move to concentrate on building the Falcon 9 and the Dragon right away, but obviously justified in retrospect. (I thought they'd need it to practice, especially after the first three launches of Falcon 1 failed.)
All the Falcon X plans are a very different matter - those are not plans, but were referred to as "brainstorming ideas". (Which may be, and very often are, silly and unrealistic.) However, if Elon wants to go to Mars, he'd better build bigger rockets rather than smaller ones.