Reggie-

People in Japan are far more vulnerable to radiation leaks from this troubled nuclear power complex than people in the States or in Europe.


The transcript of from the Union of Concerned Scientists conference call on Monday, March 21, has now been posted. I find it all interested (go to the website and click on "nuclear") but here are some excepts:

INTRODUCTION

"MR. LOCHBAUM: Good morning. The power line that was run to the site on last Friday has allowed workers to attempt to start reenergizing safety equipment on Units 1 and 2. Those efforts have been slowed by the need to initially proceed cautiously because of the water-spraying efforts, both from the ground and from the air, into the spent fuel pools on Units 3 and 4. That required workers to shield the electrical cables and connections from the water that was being sprayed about. Then the efforts were further complicated by the fact that the hydrogen explosions or some damage within the reactor buildings hence required workers to run temporary lines to connect power from the line that was run to individual components in those structures. So, that's slowing down the efforts to restore a more conventional cooling system for Units 1 and 2. Units 3 and 4 continue to be the -- the priority continues to be spent fuel pool. Efforts over the weekend to get water back into the spent fuel pools largely succeeded. The radiation levels have gone down. There are indications that water in those pools has been restored and the temperatures have stabilized, whereas before, they were heading upwards. So, those conditions on 3 and 4, the spent fuel pools, have been much better than they were just a few days ago. On Units 5 and 6, the spent fuel pools have been -- their cooling systems have been reenergized. They're running. The temperatures have not only decreased, but there's now plenty of margin available that wasn't there just last week. So, conditions are improving across the board.

(snip!)

SPENT FUEL POOL DISCUSSION

REPORTER: Hi, folks. Thanks again for having these briefings. They're really useful. I'm going to ask sort of a design question. Can you talk really about whether the design of the Mark I, or Mark I, specifically the placement of the spent fuel rods containing fuel at a position that's largely above the reactor, made this situation worse. There's been a lot of sort of graphics about how these things are arranged. And in answering, if you could address whether the United States should be worried about this design in installed U.S. reactors.

MR. LOCHBAUM: This is Dave Lochbaum. The arrangement with the spent fuel pool up in upper elevations of the reactor building was a contributing factor, but the larger factors were the fact that the spent fuel pool cooling system was not -- or the spent fuel pool cooling system was not designed to withstand earthquakes. A lot of support systems are also not designed to be powered off of anything other than the electrical grid. So, when the earthquake and tsunami took out the formal power and the backup power, it caused a lot of damage to equipment, nonsafety-related equipment or nonseismically supported equipment, at the plant, the pools were left with nothing that could cool the water.
In addition, the loss of some of the support systems, like the air system, meant that it was possible that the inflatable seals around the gates in the pools deflated and allowed water to leak out of the pool, plus that's in a not very robust building. Unlike the reactor core that's within a concrete wall that's four to five foot thick, it's up there with sheet metal siding around it.

So, in addition, if the water level in the spent fuel pool did drop below the top of the irradiated fuel and hydrogen was generated, inside the main containment building, there is systems to deal with hydrogen, to detect it, to measure what the concentration is, and to do something about it. In the reactor building, there is no such equipment to deal with hydrogen that's produced, and, therefore, the hydrogen explosions occurred. If we were in the situation that they were, the design didn't give the workers much chance to deal with the situation they faced."

I was shocked to read that these plants were licensed to function with no back-up coolant system for their spent fuel pools, in the event of a loss of power to the complex.

Evidently the 7th spent fuel pool, referred to as the common spent fuel pool, the one that is stuffed with older fuel rods, has elevated temperatures but not high enough to attract any concern on the part of plant supervisors.

Charley Noble