The current plan is to come up with a general idea for a fix shortly, have each plant design its own specific version of that general fix by May 2005, have the modifications all made by June 2007 and the paperwork all turned in by December 2007. So far, the agency's latest report adds, they're actually running a wee bit behind schedule.
But it turns out this long-known problem could be more serious than suspected.
Last year, a study the NRC commissioned from the Los Alamos National Laboratory looked at sixty-nine of America's 103 nuclear power reactors--those designed to keep coolant water under heavy pressure, and so designated Pressurized Water Reactors, or PWRs--and asked how likely it was that their collecting pool pumps ("containment sumps") might clog at critical moments. Los Alamos, which has looked at this issue repeatedly over the years for the NRC, came back with a startling answer: Very likely. So likely, in fact, that a disaster at a nuclear plant is one hundred times more likely than previously believed.
Lochbaum, the nuclear safety expert with the Union of Concerned Scientists, found the numbers shocking. He rearranged the equations to spread the year-to-year risk of a major loss-of-coolant catastrophe across all sixty-nine American pressurized water reactors. His numbers:
Chance of a disaster by next year: one in ten.
Chance by 2005: one in five.
By 2006: one in four.
By 2007: one in three.
And if the NRC, which plans to have the problem fixed by 2008, gets delayed until, say, 2010? The chance of catastrophe rises to one in two.
What if the problem was fixed this this year at all relevant reactors? Then, Lochbaum says, the NRC could truthfully tell the American public that their numbers show a 99.9 percent chance of not having a loss-of-coolant catastrophe in the next year.
NRC: Just "Remove the Conservatism"
The NRC, in a written reply to questions from The Nation, accepted Lochbaum's interpretation of the Los Alamos study. Yes, the NRC wrote, according to its own commissioned study there's a one-in-three chance of disaster by 2007, which is why, the agency explained, it sent the report back for more work.
"The reason that the NRC commissioned Los Alamos Laboratories to analyze the sump blockage issue was to determine the credibility of that safety issue and to determine whether the agency should move forward with requiring a solution," wrote Gregory Cranston, a staff member in--take a deep breath--the Office of Nuclear Reactor Regulation's Division of Systems Safety and Analysis.
"Upon receiving the August 2002 report from Los Alamos Laboratories, the NRC, based on the significance of the conclusions reached, requested that a second report be prepared," one that "removed some conservatism from the original risk analysis." No, it didn't just pull out the bad news: The second report looked at mitigating actions and technologies, "such as standard operator action to recover from the accident," and "appropriate consideration of general design criteria related to leak-before-break technology."
So the NRC got a shocking report from Los Alamos National labs, and sent it back. It told the Los Alamos team to plug in new assumptions and to consider the concept of "leak-before-break technology"--the idea that equipment is carefully monitored in a nuclear plant, so a pipe that starts to leak a bit will sound alarms long before it bursts, leaving time to head off potential problems.
Los Alamos duly served up a new report in February 2003, one that plugged in those new NRC-mandated assumptions.
"Therefore, by removing some of the conservatism and using the same formula that was used by the UCS, the one in three chance...is significantly reduced to less than one chance in 100 (or less than a one percent chance)," Cranston writes.
"Additionally," Cranston concludes, "it should be noted that the safety record of nuclear power reactors has been quite good and, in fact, since the Three Mile Island event nearly a quarter of a century ago, there has not been a serious accident at any nuclear power plant."