LAPUR 5.2 Verification and User's Manual (NUREG/CR-6696)

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Publication Information

Manuscript Completed: November 2000
Date Published: February 2001

Prepared by:
A. Escrivd,* J. March-Leuba

Oak Ridge National Laboratory
Managed by UT-Battelle, LLC
Oak Ridge, TN 37831-6004

*Polytechnic University of Valencia
46022 Valencia, Spain

T.L. Huang, NRC Project Manager

Prepared for:
Division of Systems Safety and Analysis
Office of Nuclear Reactor Regulation
U.S. Nuclear Regulatory Commission
Washington, DC 20555-0001

NRC Job Code J6042

Availability Notice


This report documents a series of programming upgrades to increase the available number of thermal-hydraulic regions (i.e., channels) and other parameters in LAPUR. LAPUR, a computer program in FORTRAN, is a mathematical description of the core of a boiling water reactor. Its two linked modules, LAPURX and LAPURW, respectively solve the steady state governing equations for the coolant and fuel and the dynamic equations for the coolant, fuel, and neutron field in the frequency domain. General implementation descriptions are followed by a detailed description of input and output parameters of LAPURX and LAPURW. Sample inputs are included and stability benchmarks are noted. The original version of LAPUR was limited to seven channels; the current version, LAPUR 5.2, has been verified with up to 200 channels, each of which can have its own axial and radial power shape. Other significant parameter upgrade is the calculation of the transfer functions for up to 100 frequencies. All code dimensions are now parameterized and can be increased if necessary.

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