It looked like this:In 2002, the plant, Davis-Besse, in Oak Harbor, Ohio, developed leaks in parts on the vessel head, allowing cooling water from inside the vessel, at 2,200 pounds per square inch of pressure, to leak out. The cooling water contains boric acid, which is used to control the speed of the nuclear reaction, and the acid ate away a chunk of the steel the size of a football, leaving nothing but a thin stainless-steel liner to maintain the reactor's integrity.
Which is pretty horrifying. There was only 3/8 of an inch of stainless steel between safety and a repeat of Three Mile Island. The incident was labeled a "near-miss" and vessel heads were inspected around the country. While it was discovered that other units had experienced leakage, none had been as bad as the Ohio Davis-Besse plant. To this day, experts remain unsure why that plant experienced more severe leakage. And perhaps that's part of the reason that it's happening again:
The company assumed it had solved the problem. But recently the new vessel head showed the same leakage pattern. Once again, the parts prone to leaking are nozzles through which the control rods for the reactor pass. When the rods are inserted, they choke off the flow of neutrons that sustains the reaction; when they are withdrawn, the reactor starts up. But the nozzles are prone to a problem called "stress corrosion cracking,'' leading to the leaks.And despite the persistent leakage, the owner of the plant will continue operating it, albeit in a shorter production run. But the long-term fix to the leak -- installing a new vessel head with a sturdier alloy -- won't be done until 2014. Which is rather alarming, considering that last time these signs of leakage were observed, acid ended up eating a football-sized hole into the steel lid that supports the integrity of the nuclear reactor.
...these signs of leaks and other indicators of accidents-waiting-to-happen should be taken more seriously than ever, and regulatory agencies like the Nuclear Regulatory Commission should be put into action -- especially as the nuclear industry gets ready to build new plants for the first time in decades.
If there's any lesson to be learned from the BP Gulf spill, and the Massey coal mine tragedy before it, it's that functioning regulation must be firmly in place, and that we as a nation habitually underestimate the dangers inherent in our current energy policy. Nuclear power