SOME ASPECTS OF THE WTR AND SL-1 ACCIDENTS

Abstract

For presentation at International Atomic Energy Agency Symposium on Reactor Safety, Vienna, Austria, May 14The Westinghouse Testing Reactor (WTR), a privately owned 60 megawatt tank type reactor, underwent a fuel element failure on April 3, 1960. A meltdown of one fuel element occurred causing the spread of fission products through the reactor cooling system. There were no casualties or overexposures. The cause of the accident could not be established beyond a reasonable doubt, but the possible cause appeared to be a cladding failure at a bonding defect. The Stationary Low Power Reactor No. 1 (SL-1), a 3 megawatt prototype reactor, underwent a nuclear excursion at the U. S. Atomic Energy Commission's National Reactor Testing Station (NRTS), Idaho, on January 3, 1961. The three military operators on duty at the time received fatal injuries and the core experienced severe damage. Large amounts of radioactivity were released inside the reactor building; however, release of radioactivity from the building to the atmosphere was slight. This was the first fatal reactor accident in the history of reactor operation in the United States. Prior to the accident, the reactor had operated for 931 megawatt days, approximately 40% of its core life. Primary efforts subsequent tomore » the SL-1 accident consisted of removal of the victims from the reactor building, determination of the nuclear status of the reactor, and analysis of the cause of the accident, including dismantling of the facility. Since the cause of the SL-1 accident was not known, work on the dismantling and decontamination of the reactor building had to proceed slowly lest some important evidence might be overlooked. The high radiation levels inside the reactor building also played an important part in slowing up the recovery operations. By the end of November 1961, the pressure vessel with the SL-1 core had been removed from the reactor building and transported 40 miles to a large hot cell on the testing station previously used to disassemble large experimental reactors. In the hot cell more detailed examination of the disarranged core proceeded. (auth)« less