Mechanistic Prediction of Fission-gas Behavior During In-cell Transient Heating Tests on LWR Fuel Using the GRASS-SST and FASTGRASS Computer Codes
Mechanistic Prediction of Fission-gas Behavior During In-cell Transient Heating Tests on LWR Fuel Using the GRASS-SST and FASTGRASS Computer Codes

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Published: 1979

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GRASS-SST and FASTGRASS are mechanistic computer codes for predicting fission-gas behavior in UO2-base fuels during steady-state and transient conditions. FASTGRASS was developed in order to satisfy the need for a fast-running alternative to GRASS-SST. Althrough based on GRASS-SST, FASTGRASS is approximately an order of magnitude quicker in execution. The GRASS-SST transient analysis has evolved through comparisons of code predictions with the fission-gas release and physical phenomena that occur during reactor operation and transient direct-electrical-heating (DEH) testing of irradiated light-water reactor fuel. The FASTGRASS calculational procedure is described in this paper, along with models of key physical processes included in both FASTGRASS and GRASS-SST. Predictions of fission-gas release obtained from GRASS-SST and FASTGRASS analyses are compared with experimental observations from a series of DEH tests. The major conclusions is that the computer codes should include an improved model for the evolution of the grain-edge porosity.

Mechanistic Prediction of Transient Fission-gas Release from LWR Fuel. [UO/sub 2/].
Mechanistic Prediction of Transient Fission-gas Release from LWR Fuel. [UO/sub 2/].

Author:

Publisher:

Published: 1978

Total Pages:

ISBN-13:

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The steady-state and transient gas release and swelling subroutine (GRASS-SST) is a mechanistic computer code for the prediction of fission-gas behavior in UO/sub 2/-base fuels. GRASS-SST treats fission-gas release and fuel swelling on an equal basis and simultaneously treats all major mechanisms that influence fission-gas behavior. The GRASS-SST transient analysis has evolved through comparisons of code predictions with the fission-gas release and physical phenomena that occur during reactor operation and transient direct-electrical heating (DEH) testing of irradiated light-water reactor fuel. The GRASS-SST steady-state analysis has undergone verification for end-of-life fission-gas release and intragranular bubble-size distributions. The results of GRASS-SST predictions for transient fission-gas release during DEH tests are in good agreement with experimental data.

Mechanistic Prediction of Transient Fission-gas Release from LWR Fuel. [UO2].
Mechanistic Prediction of Transient Fission-gas Release from LWR Fuel. [UO2].

Author:

Publisher:

Published: 1978

Total Pages:

ISBN-13:

DOWNLOAD EBOOK

The steady-state and transient gas release and swelling subroutine (GRASS-SST) is a mechanistic computer code for the prediction of fission-gas behavior in UO2-base fuels. GRASS-SST treats fission-gas release and fuel swelling on an equal basis and simultaneously treats all major mechanisms that influence fission-gas behavior. The GRASS-SST transient analysis has evolved through comparisons of code predictions with the fission-gas release and physical phenomena that occur during reactor operation and transient direct-electrical heating (DEH) testing of irradiated light-water reactor fuel. The GRASS-SST steady-state analysis has undergone verification for end-of-life fission-gas release and intragranular bubble-size distributions. The results of GRASS-SST predictions for transient fission-gas release during DEH tests are in good agreement with experimental data.