A study of temperature coefficients of reactivity for a Savannah River Site tritium-producing charge
Temperature coefficients of reactivity have been calculated for the Mark 22 assembly in the K-14 charge at the Savannah River Site. Temperature coefficients are the most important reactivity feedback mechanism in SRS reactors; they are used in all safety analyses performed in support of the Safety Analysis Report, and in operations to predict reactivity changes with control rod moves. The effects of the radial location of the assembly in the reactor, isotope depletion, and thermal expansion of the metal components on the temperature coefficients have also been investigated. With the exception of the dead space coefficient, all of the regional temperature coefficients were found to be negative or zero. All of the temperature coefficients become more negative with isotopic depletion over the fuel cycle. Coefficients also become more negative with increasing radial distance of the assembly from the center of the core; this is proven from first principles and confirmed by calculations. It was found that axial and radial thermal expansion effects on the metal fuel and target tubes counteract one another, indicating these effects do not need to be considered in future temperature coefficient calculations for the Mark 22 assembly. The moderator coefficient was found to be nonlinear with temperature; thus, the values derived for accidents involving increases in moderator temperature are significantly different than those for decreases in moderator temperature, although the moderator coefficient is always negative.
- Research Organization:
- Westinghouse Savannah River Co., Aiken, SC (United States)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC09-89SR18035
- OSTI ID:
- 5667435
- Report Number(s):
- WSRC-MS-91-303; CONF-920308-15; ON: DE92009440
- Resource Relation:
- Conference: Advances in reactor physics, Charleston, SC (United States), 8-11 Mar 1992
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
PRODUCTION REACTORS
REACTOR PHYSICS
REACTIVITY
TEMPERATURE COEFFICIENT
SAVANNAH RIVER PLANT
BURNUP
FEEDBACK
G CODES
MODERATORS
REACTOR CONTROL SYSTEMS
REACTOR SAFETY
COMPUTER CODES
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NATIONAL ORGANIZATIONS
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