Nuclear Reactor Eaten by Leaky Acid, Again by

[Robbien]

Back in 2002, an Ohio nuclear power plant developed a leak that allowed highly pressurized cooling water containing boric acid to seep out. That acid ate away a football-sized hole into the 6-inch steel lid to the nuclear reactor, leaving the reactor's integrity at grave risk. The cause of the narrowly averted disaster was thought to have been fixed, but the New York Times reports that signs of even more leakage have been showing up again -- again stoking fears of poor safety.

Nuclear Near-Catastrophe
The New York Times reports:

a nuclear reactor where a hidden leak caused near-catastrophic corrosion in 2002 has experienced a second bout of the same problem.

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.

It looked like this:



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 When the rods are inserted, they choke off the flow of neutrons that sustains the reaction; when they are withdrawn, the reactor starts up.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.

more . . .

http://www.treehugger.com/files/2010/06/nuclear-reactor-eaten-leaky-acid-again.php

[WHEN CRABS ROAR]

1. Are we learning anything yet?

[Tesha]

2. But DU's resident pro-nuke "expert" *ASSURES US* all is well! (NT)

[WhiteTara]

3. and if you don't agree with him/her

you will be severely bashed about the head and shoulders with "facts" about how much more terrible coal is.