TEPCO Unveils Plan To Deal With Fukushima Crisis

RedEaredSlider writes "Tokyo Electric Power Co. unveiled its plan for dealing with the crisis at the Fukushima Daiichi nuclear power plant, the worst nuclear disaster since Chernobyl. TEPCO said the radiation levels should drop over the next three months. It will take about six months for the reactors to achieve 'cold shutdown' in which the temperature of the water inside the reactor is less than 100 degrees Celsius (212 F). The current plan for cooling the reactors will mean injecting nitrogen into the reactor pressure vessel. All four damaged reactors experienced hydrogen explosions when water, heated by nuclear fuel, turned to steam and reacted with the zirconium alloy cladding of the fuel rods. Hydrogen, when exposed to oxygen, combusts. Nitrogen is an inert gas, so TEPCO hopes that it will prevent further explosions."

Comments

Best laid plans

[divec]

I wonder WTF their contingency plan is if a big tsunami hits now ...

I strongly believe we know how to set up technical systems for safe nuclear power. However I'm extremely sceptical of the idea that we know how to set up social / administrative systems for safe nuclear power. It's too easy to hide systemic weakness behind secrecy, or too embarrassing to identify and fix present failings, or the debate gets too polarised and ideological so people, politicians and regulatory systems lose sight of the actual safety issues because of the headline effect etc.

I wouldn't be quick to blame money or corruption or unscrupulous people, either. The key problem is secrecy -- even without malice, familiarity makes you blind to system flaws -- we software people know this very well. Only total transparency can ensure that flaws do not get hidden. On the other hand I don't know how this can be reconciled with security against sabotage.

There's a need for a sober, measured debate about all this and it's a pity that a few fundamentalists (on both sides) are making this impossible.

Re:Best laid plans

[BlueParrot]

To give you an idea of just how retarded political and administrative dealings with nuclear power is, consider what we've been doing in Sweden. Nuclear was bad, so we banned construction of new reactors, then we closed down one of our existing plants, replacing its energy generation by turning up the power on the other plants ( thereby reducing safety margins). Now because the renewables that were supposed to replace nuclear didn't make it (surprise surprise ), we will extend the reactor lifetimes by 50% or so.

I.e, rather than building newer and safer designs we have cranked up the power on the old ones and extended their operation permits beyond their design lifetime, and we still don't have any plausible way to replace them other than some wishful thinking about wind power. We're not building new reactors, so the obvious outcome will be further life extensions to our already ageing reactor fleet. Then when they finally do fall apart at 6+ decades of operation, it will all be because nuclear is inherently dangerous, and not at all because we stopped its development and improvement for 40 years and decided to go with a wind power pipe dream that saw the reactors pushed way beyond what they were ever designed for.

If it was down to me we would be building ESBWR or CANDU reactors for the short to medium term, with an aim of Lead or Molten Salt cooled breeders in the long term, but there's far too many people here who honestly think we will replace Petrol and Nuclear with Wind farms and Solar Photovoltaics. Yes, Solar, in Sweden ... It isn't even economical in California, but somehow we expect to do better because we're not Americans.

Re:Best laid plans

[lennier]

rather than building newer and safer design

There's a big unstated "if" in that phrase, and that's that newer reactor designs are in fact safer.

I mean, technically, on paper, sure, these third and fourth generation designs em>sound safer. Passive cooling, foolproof, failsafe, etc, etc. It's all very nice and clean and clinical. On paper.

But weren't last few generations of reactors also supposed to be literally failsafe? Never in a thousand years would we see the types of accidents we've had five or so of in the last forty years? We were assured that by people who literally swore on their childrens' lives that it would be perfectly safe.

And of course, the only way we can tell for sure if these new designs - which of course are going to be "lighter" and "cheaper" because they'll have smaller containments - is to build them and run them. And then there'll be pressure to rapidly deploy them. Oh, what does that remind me of? a little thing called the "boiling water reactor" which was a second generation model improved from the old clunky pressurised water systems and didn't need the big heavy containment, because it had this neat "torus" to suppress leakage?

But these new reactors are different you say? Of course they are. They're built by the same companies who made the old, inferior, should never have been deployed ones? Gee, now that's an odd coincidence. I'm sure there's nothing to it. I'm sure we can trust this new generation of nuclear advocates in exactly the way we couldn't trust their fathers.

Lie to me once, shame on me. Lie to me twice... don't let the spent fuel pool blow up and contaminate your farmland on the way out.

Re:Best laid plans

[lennier]

solar lobbies.

Yeah, who do those freaking sun-lovers think they are? Don't they realise if we all use the sun it will go out faster?

Re:Half-life

[blair1q]

You would hope. But given that they don't seem to have been prepared for foreseen circumstances*, I'm not betting on their team until I see management make some trades.

* - the 10-meter tsunami was the unforeseen circumstance. Everything after it was foreseeable, and there were design choices that guaranteed a destructive cascade once the power went out. Allowing the buildings to explode and damage the systems used to keep the buildings from exploding more is a pretty major fuckup in the realm of reliability engineering. The use of zinc cladding, the lack of effective venting for the hydrogen, the proximity of the explosion to components that could be damaged in a hydrogen explosion, blockage of access by debris from the explosion... Someone 40 years ago said that having backup generators would prevent these things from happening, and didn't consider what if the generators simply broke and couldn't be replaced. Even though they may have known what could be done.

Oh, and there's the part about how they did get generators rushed to the site, but the electrical connections didn't match up so they couldn't use them. I'm still not sure that's been reported right, because what the fuck?

Cold shutdown is supposed to take a few days

[Animats]

Normally, cold shutdown takes a few days. At Three Mile Island, it took two weeks. Six months is worrisome. Too many more things can go wrong during that period.

They still have so little information about what's going on inside the reactors. Check the latest JAIF status report. Pressure is unknown. Temperature is unknown. Water level is unknown. "Fuel rods exposed partially or fully". Reactors 1 and 3 are buried under piles of rubble. And they have to fix the plumbing under that debris.

Re:Not inert at all.

[blair1q]

Sigh.

N2 is inert, unless they're planning on planting peanuts in the reactor room...

Re:Liquid N2?

[Solandri]

Liquid nitrogen is less effective than water at extracting heat. I ran through the calcs a few weeks ago:
http://news.slashdot.org/comments.pl?sid=2039038&cid=35501128

Re:Half-life

[camperslo]

I'm saying they don't really have to do anything else, and basically aren't, besides keeping stasis until the thing cools off.

Uh no. They can't just keep doing what they're doing and wait. It's more urgent than that. With the rupture in unit 2 (believed to be in the suppression tank), that water they have to keep pumping in keeps coming out bringing highly radioactive particles from the damaged fuels rods along. They pumped over 100 tons of it out of one tunnel only to have it fill back up within two days. They may have briefly interrupted what's getting into the ocean, but it is piling up and needs to be dealt with soon.

They're injecting nitrogen into unit 1 hoping to reduce the chance of a hydrogen explosion, but the pressure not rising indicates a leak. They've said it may be venting contaminated gases. (but don't be too surprised if it turns out they are unintentionally pushing more contaminated water out somewhere)

For some pretty good articles check out what the media over there are saying.

Here's a six part series on how Tepco and the government have complicated matters.
It has many details no covered by most U.S. media.

http://www.yomiuri.co.jp/dy/national/T110416002672.htm
http://www.yomiuri.co.jp/dy/national/T110415004983.htm
http://www.yomiuri.co.jp/dy/national/T110414006040.htm
http://www.yomiuri.co.jp/dy/national/T110413004031.htm
http://www.yomiuri.co.jp/dy/national/T110412006319.htm
http://www.yomiuri.co.jp/dy/national/T110411004567.htm

Re:I was more impressed by:

[fuzzyfuzzyfungus]

It's no noble gas; but N2 is pretty mild mannered. Nitrogen fixation generally requires either really clever enzymes(as with nitrogen fixing bacteria) or fairly abusive temperature and pressure along with a catalyst(as with the Haber Process). It is commonly used as a shield gas for welding of many of the less zesty metals; because it is probably the best-placed material on the cost/inertness curve. Nitrogen, liquid or compressed gas, is dirt cheap compared to any genuinely inert gas, and is inert enough for quite a few applications.

Compounds with a high proportion of nitrogen atoms, on the other hand, are to be considered guilty until someone who loves their fingers less than you do has finished proving them innocent...

Re:reactor lifetimes

[fnj]

So you don't think the metal pressure vessels, piping and fittings corrode and degrade under conditions of very high temperature, pressure, and nuclear radiation? They will never be as safe as the day they were built because it's not practical to inspect constantly and thoroughly enough to catch every single flaw before it becomes the least bit dangerous. The difference is if a coal, oil, or gas plant blows a pipe, a bunch of non-radioactive steam escapes, maybe kills some personnel on site, and maybe causes some fairly expensive damage. In a nuclear plant, there is always that possibility that a failure may progress to the catastrophic complete devastation of the entire site and some of the surrounding area.