RSICC CODE PACKAGE PSR-470

1. NAME AND TITLE

NORMA-FP: Code System to Perform Neutronic and Thermal-Hydraulic Subchannel Analysis from Converged Coarse-Mesh Nodal Solutions.

2. CONTRIBUTORS

Synthesis Srl, Milano, Italy and ENEL SpA, Milano, Italy through the OECD Nuclear Energy Agency Data Bank, Issy-Les Molineaux, France.

3. CODING LANGUAGE AND COMPUTER

Fortran 77; PC 486 (P00470PC58600).

4. NATURE OF PROBLEM SOLVED

NORMA-FP is an auxiliary program which can perform a neutronic and thermal-hydraulic subchannel analysis, starting from global core calculations carried out by both PSR-471/NORMA or PSR-492/QUARK codes. Detailed flux and power distributions inside homogenized nodes are computed by a two-stage bivariate interpolation method, upon separation of the axial variable for which an analytical solution is adopted. The actual heterogeneous structure of a node is accounted for by fuel rod power factors computed as functions of burnup, burnup-weighted coolant density, and instantaneous coolant density.

5. METHOD OF SOLUTION

The computational procedure requires node-averaged cross-sections and group fluxes and nodal face-averaged partial currents and discontinuity factors, all of which are supplied by the restart files of NORMA or QUARK. The outgoing partial currents are the basic unknowns of the Polynomial Nodal Method (PNM) of NORMA, whilst they are to be unfolded from the nodal net leakages which are dealt with by the Analytic Nodal Method of QUARK (the unfolding is performed in the output section of QUARK.) When required, a detailed three-dimensional fuel rod power distribution for a whole channel can be obtained; and a thermal-hydraulic subchannel analysis can be performed by a program section based on the COBRA-EN model.

6. RESTRICTIONS OR LIMITATIONS

The data-dependent arrays are contained in the named common block BLANK whose standard length can be changed by modifying a PARAMETER statement in the source file (see the Installation Directions).

7. TYPICAL RUNNING TIME

The test cases ran in about 20 seconds on a Pentium III processor of 500 MHZ.

8. COMPUTER HARDWARE REQUIREMENTS

NORMA runs on a Personal Computer with 486 or Pentium processor and at least 8 Mb of RAM.

9. COMPUTER SOFTWARE REQUIREMENTS

The code is written almost entirely in FORTRAN 77 and was developed with MS FORTRAN Power Station Compiler. The included PC executables were created with Digital Visual Fortran Version 6.0A and tested at RSICC on a Pentium/266 under Windows95.

10. REFERENCES

a) Included in documentation:

E. Brega, R. Fontana, E. Salina, "The NORMA-FP Program to Perform a Subchannel Analysis from Converged Coarse-Mesh Nodal Solutions (Rev. 3)," ENEL-DSR-CRTN-N5/91/05/M (September 1991).

b) Background references:

E. Salina, G. Alloggio, E. Brega, "QUARK: a Computer Code for the Neutronic and Thermal-Hydraulic Space- and Time-Dependent Analysis of Light Water Reactor Cores by Advanced Nodal Techniques," Synthesis Srl, rep. 1034/1 prepared for ENEL-ATN/GNUM (September 1994).

E. Salina, E. Brega, "The NORMA Program for Simulating the Long-Term Neutronic and Thermal-Hydraulic Behavior of Large LWR's by Three-Dimensional Coarse-Mesh Diffusion Methods," Synthesis Srl, rep. 1034/2 prepared for ENEL-ATN/GNUM (July 1995).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document in (10.a) and two DS/HD diskettes containing the FORTRAN source files, the documentation files (in WinWord 2.0C) and the input/output files for the sample problem described in User's Manual transmitted as self-extracting compressed DOS files.

12. DATE OF ABSTRACT

June 2000.

KEYWORDS: LWR; REACTOR SAFETY; THERMAL HYDRAULICS