NRC to OK Start-Up of Plant Despite Bolt Damage

Despite damage to bolts holding an important thermal shield in Unit 1 at the San Onofre nuclear power plant, federal regulators plan to give permission for the plant’s operators to start up the reactor.

Lando Zech, chairman of the Nuclear Regulatory Commission, said in a letter to four San Diego congressmen that problems with the bolts do not threaten safe operation of the reactor.

Nonetheless, Congressman Jim Bates (D-San Diego) continued to press Friday for officials to delay restarting the plant, arguing that the NRC in 1987 required operators of a Connecticut reactor with similar problems to do repairs before resuming operations.

Bates also has requested that the NRC hold a hearing on the issue before the reactor is fired up, suggesting that some critics may have misunderstood a deadline for requesting such a forum.

Typographical Error

Because of a typographical error, a notice published March 2 in the Federal Register said that hearing requests had to be filed by April 3, 1988, instead of the correct date of April 3, 1989.

Despite those arguments, an NRC spokesman in Washington said Friday that the agency will probably give the plant’s operators, Southern California Edison, permission early next week to start up Unit 1.

The thermal shield, a 2 1/2-inch-thick cylinder that absorbs gamma rays from the nuclear core, rests on six supporting blocks and is linked to the reactor floor by 30 bolts. Three of those bolts have come partly unscrewed, and others appear to be in a degraded condition.

Although critics worry that problems with the bolts could cause the shield to come loose and block the flow of reactor coolant, Zech said his staff agrees with an Edison assessment that such a scenario is highly unlikely.

“The analysis concludes that the thermal shield will remain safely in place, or, in the unlikely event it should move, flow to the reactor core would not be significantly affected,” Zech said.

Monitoring Condition of Shield

Zech also noted that Edison plans to carefully monitor the condition of the thermal shield and promises to shut down immediately if problems arise.

At the very latest, the utility will make repairs when the reactor is again shut down for servicing about January, 1991.

Southern California Edison officials discovered the problem bolts earlier this year during an inspection of the reactor core during refueling at Unit 1.

Greg Cook, the NRC’s Western Region spokesman, said Southern California Edison officials want to delay repairs because they would require removing all the fuel from the reactor core at a time when storage space for the spent material is scarce at Unit 1.