#1: [转帖] Japan Crisis Puts Spotlight on Reactors in U.S. (1865 reads) 作者: nanonano, 时间: 2011-3-17 周四, 11:43 — 作者：nanonano 在 海归商务 发贴, 来自【海归网】 http://www.haiguinet.com
"Though the exact causes of the Japanese problems remain unclear, experts said several areas appeared to be a probable focus of regulatory attention in coming months.
One key lesson, Mr. Gasser said, was that plants need to be able to restore power quickly in the event of an emergency. The Fukushima Daiichi plant lost power in the tsunami that followed Friday's massive quake, leaving reactors without normal water-circulation cooling. As a result, fuel rods inside the reactors overheated, leading to a series of explosions and radiation releases.
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Another focus could be the adequacy of containment structures—a last line of defense to prevent radiation release. So-called Mark I containment structures surround the nuclear reactors at Fukushima Daiichi and the 23 U.S. reactors. But they are smaller and weaker than containment structures built later —Mark IIs and Mark IIIs—which can withstand greater internal pressure. In an emergency, operators of the later plants would have more ability to vent heat from a crippled reactor and hold it within containment structures without needing to release it to the atmosphere to relieve pressure, as Daiichi's owners have done repeatedly. Venting has led to at least three hydrogen explosions and radioactive release.
General Electric Co. said modifications were made to Mark I structures, at least in the U.S., in the 1980s after tests of Mark III designs exposed weaknesses common to all the structures. GE said it suggested similar changes in Japanese units but was still trying to determine if they were made."
