Cappiello ‘11 (Dina, reporter for the AP March 29, 2011 “AP IMPACT: Long Blackouts Pose Risk to US Reactors” The Post and Courier http://www.postandcourier.com/news/2011/mar/29/ap-impact-long-blackouts-pose-risk-us-reactors/?print)
Long before the nuclear emergency in Japan, U.S. regulators knew that a power failure lasting for days at an American nuclear plant, whatever the cause, could lead to a radioactive leak. Even so, they have only required the nation’s 104 nuclear reactors to develop plans for dealing with much shorter blackouts on the assumption that power would be restored quickly. In one nightmare simulation presented by the Nuclear Regulatory Commission in 2009, it would take less than a day for radiation to escape from a reactor at a Pennsylvania nuclear power plant after an earthquake, flood or fire knocked out all electrical power and there was no way to keep the reactors cool after backup battery power ran out. That plant, the Peach Bottom Atomic Power Station outside Lancaster, has reactors of the same older make and model as those releasing radiation at Japan’s Fukushima Dai-ichi plant, which is using other means to try to cool the reactors. And like Fukushima Dai-ichi, the Peach Bottom plant has enough battery power on site to power emergency cooling systems for eight hours. In Japan, that wasn’t enough time for power to be restored. According to the International Atomic Energy Agency and the Nuclear Energy Institute trade association, three of the six reactors at the plant still can’t get power to operate the emergency cooling systems. Two were shut down at the time. In the sixth, the fuel was removed completely and put in the spent fuel pool when it was shut down for maintenance at the time of the disaster. A week after the March 11 earthquake, diesel generators started supplying power to two other two reactors, Units 5 and 6, the groups said. The risk of a blackout leading to core damage, while extremely remote, exists at all U.S. nuclear power plants, and some are more susceptible than others, according to an Associated Press investigation. While regulators say they have confidence that measures adopted in the U.S. will prevent or significantly delay a core from melting and threatening a radioactive release, the events in Japan raise questions about whether U.S. power plants are as prepared as they could and should be. A top Nuclear Regulatory Commission official said Tuesday that the agency will review station blackouts and whether the nation’s 104 nuclear reactors are capable of coping with them. As part of a review requested by President Barack Obama in the wake of the Japan crisis, the NRC will examine “what conditions and capabilities exist at all 104 reactors to see if we need to strengthen the regulatory requirement,” said Bill Borchardt, the agency’s executive director for operations. Borchardt said an obvious question that should be answered is whether nuclear plants need enhanced battery supplies, or ones that can last longer. “There is a robust capability that exists already, but given what happened in Japan there’s obviously a question that presents itself: Do we need to make it even more robust?” He said the NRC would do a site-by-site review of the nation’s nuclear reactors to assess the blackout risk. “We didn’t address a tsunami and an earthquake, but clearly we have known for some time that one of the weak links that makes accidents a little more likely is losing power,” said Alan Kolaczkowski, a retired nuclear engineer who worked on a federal risk analysis of Peach Bottom released in 1990 and is familiar with the updated risk analysis. Risk analyses conducted by the plants in 1991-94 and published by the commission in 2003 show that the chances of such an event striking a U.S. power plant are remote, even at the plant where the risk is the highest, the Beaver Valley Power Station in Pennsylvania. These long odds are among the reasons why the United States since the late 1980s has only required nuclear power plants to cope with blackouts for four or eight hours. That’s about how much time batteries would last. After that, it is assumed that power would be restored. And so far, that’s been the case. Equipment put in place after the Sept. 11, 2001, terrorist attacks could buy more time. Otherwise, the reactor’s radioactive core could begin to melt unless alternative cooling methods were employed. In Japan, the utility has tried using portable generators and dumped tons of seawater, among other things, on the reactors in an attempt to keep them cool. A 2003 federal analysis looking at how to estimate the risk of containment failure said that should power be knocked out by an earthquake or tornado it “would be unlikely that power will be recovered in the time frame to prevent core meltdown.” In Japan, it was a one-two punch: first the earthquake, then the tsunami.
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