Undamaged TMI Reactor Is Restarted

Technicians triggered a nuclear chain reaction Thursday to restart the undamaged Unit 1 reactor at Three Mile Island, dormant since its sister reactor caused the nation’s worst commercial nuclear accident 6 1/2 years ago.

“The process went very smoothly. There weren’t any problems,” Lisa Robinson, spokeswoman for the plant’s operator, GPU Nuclear Corp., said after the self-sustaining chain reaction started shortly before 2 p.m.

Over the protests of demonstrators but with the U.S. Supreme Court’s approval, operators began lifting some of the 69 control rods out of the reactor at 4:30 a.m. to allow the radioactive uranium fuel to build up to the chain reaction.

‘Performing Very Well’

Technicians also removed boron from the core’s cooling water. That element is often called a nuclear poison because it soaks up neutrons, the subatomic particles fired out by dividing uranium atoms that otherwise would make more atoms split.

“The plant is performing very well. We’re very pleased,” said Philip R. Clark, president of GPU, which operates the plant for General Public Utilities Corp. “The instructions to the crew are to proceed deliberately and safely with emphasis on safety.”

TMI Unit 1 was shut down for routine refueling during the March 28, 1979, accident that damaged the adjacent Unit 2.

A combination of human and mechanical errors allowed cooling water to drain out of Unit 2. The reactor overheated, some of its uranium fuel rods melted and radioactive materials escaped into the environment.

Unit 1 Not Affected

Although Unit 1 was not affected by the accident, the Nuclear Regulatory Commission ordered it shut down pending hearings on whether it could be operated safely.

The NRC approved the restart on May 29, but it was delayed pending court appeals by an anti-nuclear group, Three Mile Island Alert.

Final NRC approval came Thursday morning after Wednesday’s favorable ruling by the U.S. Supreme Court.

A three-member panel of the U.S. 3rd Circuit Court of Appeals in Philadelphia rejected a last-ditch plea Thursday from Three Mile Island Alert Inc. to stop the restart.

The restart of Unit 1, built in 1974 at a cost of $400 million, will mean a savings of $72 million a year by GPU ratepayers in Pennsylvania and New Jersey.