SECOND GENERATION RESEARCH REACTOR FUEL COUNTER (RRFC-II)

Year
2001
Author(s)
M. Abhold - Los Alamos National Laboratory
S.C Bourret - Los Alamos National Laboratory
D. Pelowitz - Los Alamos National Laboratory
Michael Baker - Los Alamos National Laboratory
W. Harker - Los Alamos National Laboratory
P. Polk - Los Alamos National Laboratory
Abstract
The second generation Research Reactor Fuel Counter (RRFC-II) has been developed to measure the remaining 235U content in foreign spent Material Test Reactor (MTR)-type fuel being returned to the Westinghouse Savannah River Site (WSRS) for interim storage and subsequent disposal. The fuel to be measured started as fresh fuel nominally with 93% enriched Uranium alloyed with Al clad in Al. The fuel was irradiated to levels of up to 65% burnup. The RRFC-II, which will be located in the L-Basin spent fuel pool, is intended to assay the 235U content using a combination of passive neutron coincidence counting, active neutron coincidence counting, and active-multiplicity analysis. Measurements will be done underwater, eliminating the need for costly and hazardous handling operations of spent fuel out of water. The underwater portion of the RRFC-II consists of a watertight stainless steel housing containing neutron and gamma detectors and a scanning active neutron source. The portion of the system that resides above water consists of data-processing electronics; electromechanical drive electronics; a computer to control the operation of the counter, to collect, and to analyze data; and a touch screen interface located at the equipment rack. The RRFC-II is an improved version of the Los Alamos-designed RRFC already installed in the SRS Receipts Basin for Offsite Fuel. The RRFC-II has been fabricated and is scheduled for installation in late FY 2001 pending acceptance testing by Savannah River Site personnel.