Evaluation of discrepancies in assembly cross-section generator codes. Volume 4, Doppler evaluation, Final report

Technical Report · Thu Jul 01 00:00:00 EDT 1993

OSTI ID:10181299

Fisher, J R; Grow, R L ^[1]

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1. Utility Resource Associates, Rockville, MD (United States)

Utilities employ different cross section generators (EPRI-CELL, CPM, CASMO), different versions of these generators and different libraries in the generators, to produce input to different nodal codes. Phase I of this project utilized available data from utility calculations to identify the areas of differences in calculated results and to make an initial assessment of the potential impact and/or consequence of these differences. Phase II of this project investigated these differences via a consortium of utilities performing calculations for pin cells and multi-pin cells using controlled input data and options. The Phase II goal was to quantify differences and to determine if the differences were due to cross section library, cross section code methodology or the procedure for utilizing a code. The Phase III goal was to investigate the significant differences from Phase II in an assembly environment to determine if the differences changed in size. The goal of the final phase of the project was to investigate the significant differences previously identified to determine the root causes of the differences and to determine which code/library best agrees with actual physical behavior. The Doppler investigation results are contained in Volume 4. This investigation has shown that large differences, up to 30%, exist in the Doppler defect and coefficients as calculated by the various cross section generator codes. The magnitude of the differences are dependent upon exposure, presence of burnable poison, and the H{sub 2}O/UO{sub 2} ratio. The root cause of the differences has been established to be the difference in the change in the U-238 resonance integral with fuel temperature change, as calculated by the various codes.

• Research Organization: Electric Power Research Inst., Palo Alto, CA (United States); Utility Resource Associates, Rockville, MD (United States)
• Sponsoring Organization: Electric Power Research Inst., Palo Alto, CA (United States)
• OSTI ID: 10181299
• Report Number(s): EPRI-NP-6147-Vol.4; ON: UN93019962; TRN: AHC29311%%32
• Resource Relation: Other Information: PBD: Jul 1993
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
PWR TYPE REACTORS
FUEL MANAGEMENT
BWR TYPE REACTORS
ENRICHED URANIUM REACTORS
COMPUTERIZED SIMULATION
CROSS SECTIONS
FUEL ASSEMBLIES
COMPARATIVE EVALUATIONS
DATA COVARIANCES
DOPPLER COEFFICIENT
DOPPLER EFFECT
BURNABLE POISONS
TEMPERATURE COEFFICIENT
TEMPERATURE DEPENDENCE
URANIUM DIOXIDE
WATER
EPRI
FUEL ELEMENTS
210100
210200
POWER REACTORS
NONBREEDING
LIGHT-WATER MODERATED
BOILING WATER COOLED
POWER REACTORS
NONBREEDING
LIGHT-WATER MODERATED
NONBOILING WATER COOLED