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Fast Flux Test Facility Reactor Initial Criticality Predictions and Measurements

Conference · · Transactions of the American Nuclear Society
OSTI ID:7231797

The Fast Flux Test Facility (FFTF) was designed to test fast-reactor fuels and other nonfuel materials. In its 37 reactor cycles of operations, the FFTF reactor has performed very well and successfully completed all the irradiation testings with an operating efficiency factor as high as 98%. Since FFTF is an experimental reactor, its core loading changed from cycle to cycle. Depending on the number of test assemblies in the core and their location, the core loading can change significantly from an essentially homogeneous core loading to a relatively nonhomogeneous or even highly localized heterogeneous loading. Consequently, the core reload design and initial criticality analyses were required for each operating cycle. The zero power initial critical control rod bank height was predicted before each reactor startup. The initial critical prediction depends on the reactivity conditions at the end of the previous cycle, the temperature feedback reactivities, the individual and total control rod bank worths for the current cycle, the differential rod worth profile, and the refueling reactivity for the current cycle core loading. The predicted and the measured initial critical control rod bank heights for the recent cycles are summarized.

Research Organization:
Westinghouse Hanford Co., Richland, WA (United States)
Sponsoring Organization:
USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
OSTI ID:
7231797
Report Number(s):
CONF-920606--
Journal Information:
Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 65; ISSN TANSA; ISSN 0003-018X
Publisher:
American Nuclear Society
Country of Publication:
United States
Language:
English