Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Fast Flux Test Facility (FFTF) feedback reactivity components

Conference ·
OSTI ID:6736907
The static tests conducted during Cycle 8A (1986) of the FFTF have allowed, for the first time, the experimental determination of each of the feedback reactivities caused by the following mechanisms: fuel axial expansion, control rod repositioning, core radial expansion, and subassembly bowing. A semiempirical equation was obtained to describe each of these feedback components that depended only on the relevant reactor temperature (bowing was presented in a tabular form). The Doppler and sodium density reactivities were calculated using existing mechanistic methods. Although they could also be fitted with closed-form equations depending only on temperatures, these equations are not needed in transient analyses using whole core safety computer codes, which use mechanistic methods. The static feedback reactivity model was extended to obtain a dynamic model via the concept of ''time constants.'' Besides being used for transient analyses in the FFTF, these feedback equations constitute a database for the validation and/or calibration of mechanistic feedback reactivity models. 2 refs., 6 tabs.
Research Organization:
Westinghouse Hanford Co., Richland, WA (USA)
DOE Contract Number:
AC06-87RL10930
OSTI ID:
6736907
Report Number(s):
WHC-SA-0286; CONF-880506-26; ON: DE89001108
Country of Publication:
United States
Language:
English