DAVIS-BESSE NUCLEAR PLANT Anti-explosion equipment is broken

Nuclear plant workers had been turning knobs, but valves were frozen.
KNIGHT RIDDER NEWSPAPERS
AKRON -- Equipment designed to prevent a hydrogen gas explosion similar to what happened during the Three Mile Island partial nuclear meltdown has been inoperable at FirstEnergy Corp.'s Davis-Besse plant since it opened in 1977, a report shows.
For all those years, Davis-Besse technicians had followed procedures to turn knobs on the equipment that indicated interior valves were working, but the valves had actually frozen closed.
Davis-Besse workers discovered the broken equipment during a safety systems check in early May, according to the report given to the Nuclear Regulatory Commission. The Union of Concerned Scientists on Tuesday released copies of the report, which was filed June 30 with the NRC.
Other safety problems
The broken equipment is the latest in a long list of other safety problems discovered at the troubled plant in Oak Harbor, Ohio, about 25 miles east of Toledo.
FirstEnergy said backup systems likely would have detected a hydrogen gas buildup if there was a major accident inside the containment chamber, warding off the likelihood of an interior explosion. The massive concrete and steel containment chamber is the last line of defense between a malfunctioning or damaged reactor and the environment.
Valve replacement
The Akron utility will permanently replace the faulty valves with open piping, spokesman Todd Schneider said. The problem should not slow down FirstEnergy's efforts to get the plant ready to restart by the end of summer, he said.
The Nuclear Regulatory Commission will look into the matter, spokesman Jan Strasma said.
Davis-Besse and NRC inspectors are conducting thorough reviews of the plant's safety systems, Strasma said.
What happened then
At Three Mile Island, large amounts of hydrogen were created when the Pennsylvania plants' nuclear fuel overheated on March 28, 1979, David Lochbaum, the Union of Concerned Scientists' nuclear expert. About 10 hours after the accident started, the hydrogen blew up inside the containment chamber, causing the interior pressure to jump from about 3 pounds per square inch to 28 pounds per square inch, he said. That's the equivalent of putting 36 tons of pressure on a containment door that is 3 by 6 feet, he said.