Newspaper: The Sentinel
Date: April 11, 1979
Article: Moving from a troubled past …
Author: Kathy Liebler
Three Mile Island is three miles long, located three miles south of Middletown.
The property, owned by Metropolitan Edison Co. since 1906, is the site of two pressurized water nuclear reactors, Three Mile Island units 1 and 2, the 44th and 21st largest atomic reactors in the world.
Unit 1, a 792 – megawatt reactor, started commercially operating in 1974, after seven years of construction.
In 1970, construction of the larger Unit 2, a 905 – megawatt reactor, began, with commercial operation underway in December 1978.
Unit 2 became critical, that is operational when a sustained reaction was begun in the reactor core, March 28, 1978, at 4:37 a.m. Exactly one year later, almost to the hour, Three Mile Island’s Unit 2 would be the site of the world’s worst nuclear accident.
SOME CRITICS of nuclear power say, considering repeated mechanical failure during its testing period, Met-Ed should have never started up the power generating plant.
Although commercial operations of Unit 2 would not begin until Dec. 30, 1978, the reactor during its nine-month testing period prior to that time was shut down 195 of 274 days, consumer advocate Ralph Nader says. Public Citizen, a Nader “watchdog” group, has charged that Unit 2 was rushed into commercial operation Dec. 30 so the plant’s owners could save $40 million in taxes in 1978.
Nader’s report concludes that from the time Unit 2 went critical to the time it was placed in commercial service, problems and malfunctions occurred that contributed to the March 28 accident.
According to the investigation, the problems included 12 accidental trips, or malfunctions, including four that activated the emergency core cooling system, and seven shutdowns of the entire system for repairs.
The Nader report points out that despite the fact the unit was experiencing continual mechanical failures, in the nine-month period before Dec.30, Metropolitan Edison reported it had successfully completed start up tests and procedures required under the terms of its license and thereafter declared Unit 2 to be in commercial service.
THE LONG and troubled history of mechanical malfunctions is recorded in detail in records of the Nuclear Regulatory Commission.
Unit 2 has been cited for as many as 22 safety violations, with the NRC claiming that two auxiliary coolant valves, under maintenance for at least two weeks before the accident, had been kept closed until the accident occurred.
The NRC has noted the seriousness of the violation stating “there would have been an entirely different outcome if the valves would have been operating as they should have been.”
Facts compiled by Public Citizen and the staff of syndicated columnist Jack Anderson tell the story of Three Mile Island Unit 2 during its 1978 testing period and its short-lived history of commercial service.
Date and mechanical failures include:
April 1 – Unit 2 reactor trips in response to signal indicating pump failure in a primary coolant loop.
April 18 – Reactor trips due to electrical indication.
April 23 – Another electrical signal causes reactor trip and consequent turbine trip. Five of 12 main steam valves open and fail to close. Together with overfeeding of the steam generators, there is rapid loss of pressure in cooling system. Inspections later show failure of bellows due to design error and unsatisfactory performance of main steam relief valves. Plant is shut down for five months for redesign and parts replacement.
Sept. 18 – Plant is regenerated.
Sept. 20 and 25 – Reactor trips due to problems with main feed pumps.
Oct.13 – Valve in pressurizer in primary coolant system breaks down requiring shutdown of reactor.
Oct. 14 – Turbine trips due to loss of main feed water pump.
Oct. 20 – 21 – Turbine trips due to problems with power grid.
Oct. 28 – Turbine shut down for 3 ½ days for repair. Reactor is also shut down to repair a valve in the primary coolant.
Nov. 7 – Pump failure causes reactor to trip.
Nov. 21 – Feedwater system found contaminated with turbine lubricating oil, requiring 11-day clean up.
Dec. 16 – Turbine is shut down to repair main feedwater pump that will take six days.
Dec. 30 – 11 a.m.: Turbine is shut down to repair steam leak. 2:15 p.m.: Turbine is started. 11 p.m.: Plant is declared commercial, 25 hours before the end of the year.
Jan. 2, 1979 – Turbine is shut down to repair leaky valve.
Jan. 14 – Turbine shut down again because of leaky valve, also reactor is shut down to repair leaks in isolation valves connected with pressurizer.
Jan. 15 – Reactor is restarted. During a turbine trip test, the steam is released due to a loss of vacuum in condenser. A steam expansion bellows ruptures, venting steam to the control building. Power to pressurize is lost and reactor trips. Reactor is cooled to make repairs and is out of service for 17 days.
Feb. 2 – A heater pump breaks down.
Feb. 6- A main feedwater pump trips twice causing automatic reduction to 55 percent power.
Feb. 10 – Turbine is shut down to repair leaky valve in the secondary coolant system.
March 28 – Series of malfunctions occurs at Three Mile Island Unit 2 releasing significant amounts of radiation and creating significant danger of core meltdown.
Met-Ed officials, asked to comment on the plant shutdowns and mechanical failures, said, “Material is not available to confirm or deny the reports at this time.”
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