San Onofre Tampering Under Investigation

Two recent cases of tampering with equipment at the San Onofre nuclear power plant are being investigated by utility officials, the Nuclear Regulatory Commission and the FBI, plant officials disclosed Wednesday.

The two cases, neither of which involved safety-related equipment, were discovered Saturday and Tuesday, said David Barron, a spokesman for Southern California Edison Co., which operates the seaside plant.

In the first incident, someone switched colored lenses on lights that indicate the status of a ventilation system in the containment building for reactor Unit 1, Barron said. The change caused the lights to indicate that the system was not working when it actually was, he said.

In the second case, the vandal opened 10 circuit breakers in a motor control center in Unit 3, shutting off several motors that were not in service at the time. When operating, the motors run fans, pumps and valves that are part of the reactor cooling system but are not used at all times and are not critical to safety, Barron said.

“Every single pump and valve in the plant is important,” Barron said. “But you can do without a lot of them at any given time.”

Barron said the incidents did not result in any damage to plant equipment or affect the status of equipment necessary for the safe operation of the plant or for the control of radioactive material.

Nevertheless, he said the company views all tampering as a “serious matter,” whether related to safety or not. The company notified the NRC of the problem Tuesday, and the FBI visited the plant Wednesday to assist in the investigation.

Phil Johnson, a supervisor in the NRC’s western region office in Walnut Creek, said federal regulators are taking the matter seriously. Johnson said the NRC’s resident inspectors at the plant are checking other parts of the reactors to determine if any other tampering took place. In addition, an NRC official in charge of security arrived at the plant Wednesday to participate in the investigation.

“You don’t know why this person is doing the tampering, what his motivation might be,” Johnson said. “Maybe he doesn’t want to take the plant down or cause any safety problems and just wants to harass the utility. On the other hand, when you’ve got somebody who’s unhappy or disturbed, you have to assume the possibility that he or she could tamper with something that would affect safety.”

Barron said plant operators did not know who might be responsible for the tampering or why it might have been done.