MEASUREMENT OF FISSION PRODUCT ACTIVITY IN THE PEACH BOTTOM REACTOR PRIMARY COOLANT LOOP

摘要

The distribution of gamma-emitting radionuclides deposited in the primary circuit of the Peach Bottom High-Temperature Gas-Cooled Reactor (HTGR) at- end-of-life has been determined by in situ gamma scanning. The work was part of the Peach Bottom End-of-Life Program and was performed by the IRT Corporation under subcontract to General Atomic Company. The measurements were made to support a design method veri-fication exercise. The specific activity on the ducts was measured by external scans at local points with a Ge(Li) detector and by internal scans with a travelling intrinsic germanium detector (after destructive removal of trepan samples); the activity on the steam generator tube bundle was determined by traversing selected tubes with travelling CdTe detectors from the water side. Calibration measurements on mockups allowed reduction of the spectra to specific activity.