TMI-1 restart underway.

concern over events that contributed to the March 1979 Three Mile Island (TMI) Unit 2 accident quickly cast doubts about whether its undamaged twin, Unit 1, could be operated safely. so that plant--shut down at the time of the accident for a routine refueling--was forced to remain idle. As the undamaged plant's safety was studied, debated, questioned in court and appealed, TMU-1 kept silent watch over its crippled twin. That vigil ended last week.

On Oct. 2, the Supreme Court's refusal to block TMI-1's restart effectively neded the appeals process (SN: 9/7/85, p.150). At 1:30 p.m. the next day, the plant's reactor "went critical," sustaining a controlled nuclear chain reaction. Low-power testing of the plant ended two days later. For the next three months, operators will run a battery of tests as they slowly bring the plant to full power.

But most important for the Parsippany, N.J.-based General Public Utilities (GPU) Corp., owner of the plant, TMI-1 may be back in the utility's rate-paying base within three weeks. According to Gordon Tomb, a plant spokesperson at the Three Mile Island nuclear station, it's an event GPU awaist anxiously, since buying replacement power to cover the electrical demand not met by the idled plant has--over the last six and one half years--increaed the utility's costs by an estimated $1.09 billion.