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LOFT Input Dataset Reference Document for RELAP5 Validation Studies (NUREG/IA-0072, AEEW–R2454)

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Publication Information

Date Published: April 1992

Prepared by:
J. C. Birchley

Winfrith Technology Centre
United Kingdom Atomic Energy Authority
Dorchester, Dorset, DT2 8DH
United Kingdom

Prepared as part of:
The Agreement on Research Participation and Technical Exchange
under the International Thermal-Hydraulic Code Assessment
and Application Program (ICAP)

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

Availability Notice

Summary

Analyses of LOFT experiment data are being carried out in order to validate the RELAP5 computer code for future application to PWR plant analysis. The dataset used in the analyses is based on the latest available information on the LOFT facility issued by the Idaho National Engineering Laboratory (INEL), operators of the LOFT experimental facility. The dataset was developed originally by INEL, for use with RELAP5/MOD1, to support planning and analysis of LOFT experiments. The MOD1 dataset was also used by CEGB Barnwood who subsequently converted the dataset to run with MOD2. The modifications included changes to the nodalisation to take advantage of the crossflow junction option at appropriate locations. Additional pipework representation was introduced for breaks in the intact (or active) loop. Further changes have been made by Winfrith following discussion of calculations performed by the CEGB and Winfrith. These concern the degree of noding in the steam generator, the fluid volume of the steam generator downcomer, and the location of the reactor vessel downcomer bypass path.

This document describes the dataset contents relating to the volume, junction, and heat slab data for the intact loop, reactor pressure vessel, broken loop, pressuriser, steam generator secondary, and ECC system. Also described are the control system for steady state initialisation, standard trip settings, and boundary conditions.

Reactor Physics Division
AEA Technology, Winfrith

January 1990

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