The U.S. Nuclear Regulatory Commission (NRC) has released a "Near Term Report" this week that calls for a wide range of safety improvements for the U.S. fleet of 104 nuclear reactors. (Summary & Full text in PDF format at US NRC blog)The report ominously calls for "redefining the level of protection that is regarded as adequate." If that's the case, just exactly what has the agency been doing up to now? This is not gratuitous skepticism. If a federal regulatory agency calls for moving the goal posts, it's time to take a close look at its reasons for doing so.
Yet at the same time the NRC calls for change, it acknowledges that the information it has on what happened at Fukushima is "unavailable, unreliable, or ambiguous because of damage to equipment at the site." In short, the report is vulnerable to criticism that it appears to be a case of shoot first and ask questions afterwards.
The 90 page report was written in response to the earthquake and tsunami of March 11 which resulted in partial or complete meltdowns of three reactors and the destruction of the infrastructure supporting six reactors at Fukushima, Japan.
Two key areas stand out in the report. The first is the question of how nuclear utilities will deal with multiple reactors impacted by the same natural disaster and second how to address "station blackout" when both internal and external electrical power is lost. It is clear from the experience at Fukushima that four-to-eight hours of battery power and a few days of diesel generator emergency power are not good enough. See also Reuters Fact Box list of subjects covered in the NRC report.
There are lots of reasons why the 40-year old Japanese reactors would never be built in the current era. The report takes pains to point out there is "no imminent risk" for U.S. nuclear reactors. The NRC needs to take care that it doesn't over-react to problems in Japan that don't affect the U.S. fleet.
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6 comments:
Dan, why do you say this?
"It is clear from the experience at Fukushima that four-to-eight hours of battery power and a few days of diesel generator emergency power are not good enough."
The batteries and diesels were not lost due to eventual depletion (which would happen if they were undersized like your words suggest). They were lost due to a common cause (seawater) shorting them out.
It is a paradox. Infrequent events like the 1000-year tsunami that hit Fukushima do not require design mitigation to prevent core damage or partial breach of the containment.
Now that it has happened, it is no longer a 1000-year tsunami. That is the paradox.
So many people died in Japan because 101 evacuation sites were flooded. People had time to keep running but stopped because they thought they were safe.
So recent events have moved the goal posts. What are the ramifications? A relatively small air cooled SBO diesel could pump 100 gpm of ground water into the core. I have been at nukes that used well water for drinking water. It does not have to be safety related to get the job done.
Kit-
If the equipment is used to mitigate the consequences of an accident, doesn't that by definition make it safety related? Yes, commercial grade products can get the job done, and the advantages of having the "safety grade" qualification often only add a little more assurance the thing will work. But we are talking the NRC here.
Obviously, we do not understand the true risk associated with 1000 year events. If the risk associated with a 1000 year event can be reasonably expected to kill your entire industry, you would expect industry leaders to take action. Turns out that a scientist named Sishikura was predicting that the 1000 year event was overdue and TEPCO ignored him the first time he told them. Some details lifted from another Web News Source:
"[Shishakura] figured it out by looking at rocks. Looking at the rich soil in the area, he found layers of sand and pebbles that appeared to have been carried inland by tsunamis. This gave him rough dates for killer waves dating back 3,500 years. The sediment samples revealed a pattern, with the telltale strips of tsunami evidence separated by several centuries of soil buildup.
Did he warn Japanese authorities?
Yes. Shishikura and his colleagues told the government that northeastern Japan was overdue for a huge wave. The Trade Ministry dismissed the evidence, and the Tokyo Electric Power Co. did nothing to beef up defenses at Fukushima. "At the time, we thought it was unfortunate they didn't take us seriously, but we figured it was just a matter of making a better presentation," Shishikura said, as quoted by The Sydney Morning Herald. "If only the tsunami had waited a little longer, we might have been ready." He had an appointment to explain his research to Fukushima officials on March 23; the earthquake and tsunami hit March 11.
Was there any way to predict the extent of the damage?
Yes. Japan has been hit by 195 tsunamis since the year 400. In the last three decades, there have been three waves that were more than 30 feet high. Yet Tokyo Electric's seawall defenses at Fukushima were built to protect the nuclear reactors from waves reaching only 17 feet high. "That is ridiculous," says Ryohei Morimoto, a retired volcanology professor at the University of Tokyo, as quoted by The Japan Times. "Even if they couldn't predict the size of tsunami, they should have at least prepared for waves similar to those in the past.""
If that is true (In the last three decades, there have been three waves that were more than 30 feet high), someone at TEPCO and the Ministry of Trade and Industry needs to go to prison.
Keep in mind Anonymous that there was not a design basis accident in Japan. There was a natural disaster that created a ‘beyond design basis accident’. Safety related equipment is to mitigate a DBA that would prevent core damage and breaching containment. For example, hydrogen recombiners used to prevent a hydrogen detonation after a severe accident is classified as ‘non-safety related augmented quality’.
For what ever reason, human error or natural disaster, once you are not confident that core damage is not imminent; the emergency plan goes into effect and evacuation begins. Protecting people is the important issue not the cost of the cleanup.
Robin you will have to excuse me but as of late I get a little irritated those who lecture about the risk of radiation while ignoring a mountain of dead bodies. If the concept of a killer wave being much worse than predicted had been communicated such that people increased their margin of safety by running until they were out of time not just thought they were high enough.
I do not think anyone in the nuclear industry is arguing against doing the right thing whatever that might be. We are arguing against shutting down the nuclear industry because we understand the risk compared to other ways of making electricity.
So Robin if I give you $10 million, would you spend it on a break water around a nuke in Japan, a coastal city in Japan, or to prevent a cholera epidemic in Haiti?
“a case of shoot first and ask questions afterwards”
Sort of like Jaczko’s unilateral declaration of a 50-mile evacuation zone for American citizens around Fukushima, which is now being used (by design?) as a tool for antis to promote the shutdown of all plants (especially Indian Point) within that distance of a metropolitan area.
Despite an unprecedented earthquake, a thousand-year tsunami, three core meltdowns, and three large hydrogen explosions, the score is still - none dead from radiation and two with sunburned ankles.
And if the Japanese government wasn’t held hostage to the disproven Linear Non-Threshold hypothesis, the residents could return to the evacuation zone and begin rebuilding their lives with no more radiological consequences than the people of Ramsar, Iran (which, despite intense study, have been found to be none).
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