Modification of USNRC's FRAP–T6 Fuel Rod Transient Code for High Burnup VVER Fuel (NUREG/IA-0164, RRC KI 2180, IPSN 99/10)

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Publication Information

Date Published: May 1999

Prepared by:
A. Shestopalov, K. Lioutov, L. Yegorova, G. Abyshov, NSI–RRC
K. Mikitiouk, INR–RRC

Nuclear Safety Institute of Russian Research Center "Kurchatov Institute"
Institute of Nuclear Reactors of Russian Research Center "Kurchatov Institute"
Kurchatov Square 1
Moscow 12382

Prepared for:
U.S. Nuclear Regulatory Commission, Institute for Protection and Nuclear Safety
(France), and Ministry of Science and Technologies of Russian Federation

Office of Nuclear Regulatory Research
U.S. Nuclear Regulatory Commission
Washington, DC 20555-0001

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The USNRC's transient fuel rod code, FRAP-T6, has been modified to analyze pulse tests with high burnup VVER fuel rods in the Impulse Graphite Reactor (IGR). New and modified models of separate phenomena have been developed, including models for heat transfer from the cladding to the stagnant coolant, the effect of fission gas swelling on the fuel–cladding gap, and the conditions of base irradiation. Thermal and mechanical properties for the VVER's Zr-1%Nb cladding were added to MATPRO-V11, which is used by the FRAP-T6 code. Changes in the input data file are described, and a sample calculation is presented with the modified code. A FORTRAN listing for the new and modified models is given in an Appendix A.

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