Fission Product Behavior in the Peach Bottom HTGR

摘要

The Peach Bottom high temperature, gas-cooled nuclear reactor, a 115-MW(t) power station, was placed in commercial operation on June 1, 1967. Operation with the initial core ended in October 1969 after 452 equivalent full power days (EFPD) had elapsed. Power production resumed on July 14, 1970 with the second core, and continued through October 31, 1974. During this period, Core 2 accumulated 897 EFPD operation. Fission product surveillance was intensified with the initiation of Core 2 operation. The Loop 1 coolant circuit was modified to accept probes for sampling the coolant at points upstream and downstream of the steam generator, and monitoring stations were established to measure gamma-emitting fission products which were deposited along the Loop 1 coolant circuit surfaces. The locations of the sampler probes and the gamma-ray monitoring stations are identified in the schematic representation of the reactor system in Fig. 1. The samplers operated continuously while the reactor was at power, and were replaced during reactor shutdowns. Shutdown periods likewise afforded opportunities for determinations of deposited activity at the gamma-ray monitoring stations and for the collection of dust samples from the cyclone separator in the loop. In addition, extensive postirradiation examinations were made of fuel elements which had been removed from the reactor at 385 EFPD, 701 EFPD, and end-of-life. (ERA citation 03:008346)