Question -- not necessarily for UCB Lab team

Submitted by Anonymous on Mon, 2011-04-04 13:30

I've been keeping up with the IAEA's daily (sometimes, more frequent) assessments of the ongoing nuclear event at the Fukushima Daiichi Plant. Here's a link to the most recent status report:

http://www.iaea.org/newscenter/news/tsunamiupdate01.html

Scrolling down to near the bottom of section one, I find the temperature and pressure information for Reactors 1, 2, and 3. (Reactor No. 4 was not in operation at the time of the earthquake and tsunami -- I don't even believe it was fueled, though the Spent Fuel Pool for that unit is QUITE full.) I've been watching these assessments for the past few days and I am seeing a (very encouraging) "downward trend" -- temperatures (if they're accurate, which there is apparently some doubt about) seem to be regularly decreasing, and pressures too. In fact, the Unit 3 Reactor Pressure Vessel's temperature is now approaching 100 degrees, Celsius. All this is being accomplished at the same time as (based on yesterday's, or the day before's, report -- I forget) the Plant operators have been able to (very slightly) REDUCE the amount of coolant water they're pumping in on a daily basis. I read this as: Not only are they keeping the Reactors STABLE, but they're needing less and less water to do so and in fact, whatever reactivity is taking place in those RPVs is continuing to gradually slow down / cool down.

My question is: Given this information, is it looking MORE LIKELY that they will eventually affect a "cold shutdown" of these reactors (barring some unforeseen complication / accident / disaster)? And, also: Would the decreasing temperatures and pressures -- theoretically as well, decreasing reactions taking place -- indicate that, over time, LESS AND LESS radionuclides are being / will be emitted, as the pot begins to simmer at lower and lower levels?

...Or is this just wishful thinking at this point?

Thanks to anyone who can answer this.

Rick Cromack.
Allen, Texas
www.facebook.com/lonestarplano

‹ Could you give us an overall idea of what has happened over the last couple weeks Tepco ›

If they get the temps down,

Submitted by Anonymous (not verified) on Mon, 2011-04-04 15:57.

If they get the temps down, the pressure goes down, as well as the need to vent steam. The goal is as cold a shutdown as possible and then holding that state unti the decay heat is exhausted. Once there the undamaged fuel can be relocated. If power and pumping can be resumed, then the longer they cool the cores, the easier it will be to contain the mess and wait 30 years to dismantle it.

I would be less worried about the plant's status proper as for any remediation work to clean up the affected area. It's a monumental and somewhat impossible task.

Thanks much

Submitted by R. Cromack (not verified) on Mon, 2011-04-04 16:06.

Thanks for your response, Anonymous.

In the long term, you're correct, of course (about "remediation") -- although it worries me that now there's some talk out there about the basements of various buildings on-site becoming SO full of radioactive water, that the electrical systems for Reactors 5 and 6, as well as the pumping systems for the Reactor 4 (and possibly the Combined) Spent Fuel Pool, may now be threatened. (And again, in the words of Egon from "Ghostbusters": "That would be BAD.")

...But there will be NO "remediation" possible of the Pacific Ocean, naturally. We're just going to have to deal with whatever the effects are.

Rick Cromack.
Allen, Texas
www.facebook.com/lonestarplano