NEA-1324 OREST.

1. NAME OR DESIGNATION OF PROGRAM:  OREST96

3. DESCRIPTION OF PROGRAM OR FUNCTION

In OREST, the 1-dimensional lattice code HAMMER and the isotope generation and depletion code ORIGEN are directly coupled for burnup simulation in light-water reactor fuels (GRS recommended).  Aditionally heavy water and graphite moderated systems can be calculated.

New version differs from the previous version in the following features:

An 84-group-library LIB84 for up to 200 isotopes is used to update the 3-group -POISON-XS. LIB84 uses the same energy boundaries as THERMOS and HAMLET in .  In this way, high flexibility is achieved in very different reactor models.

The coupling factor between THERMOS and HAMLET is now directly transferred from HAMMER to THERES and omits the equation 4 (see page 6 of the manual).

Sandwich-reactor fuel reactivity and burnup calculations can be started with NGEOM = 1.

Thorium graphite reactivity and burnup calculations can be started with NLIBE = 1.

High enriched U-235 heavy water moderated reactivity and burnup calculations can be started. HAMLET libraries in for U-235, U-236, U-238, Np-237, Pu-238, Pu-239, Pu-240, Pu-242, Am-241, Am-243 and Zirconium are updated using resonance parameters.

A new version of the module hamme97.f has replaced the old one.

4. METHOD OF SOLUTION

For the user-defined irradiation history, an input data processor generates program  loops over small burnup steps for the main codes HAMMER and ORIGEN. The user defined assembly description is transformed to an equivalent HAMMER fuel cell.
HAMMER solves the integral neutron transport equation in a four-region cylindrical or sandwiched model with reflecting boundaries and runs with fuel power calculated rod temperatures.  ORIGEN runs with HAMMER-calculated cross sections and neutron spectra and calculates isotope concentrations during burnup by solving the buildup-, depletion- and decay-chain equations. An output data processor samples the outputs of the program modules and generates tabular works for the printer-output.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

NEA version is limited for 100 loops, 1000 burnup timesteps and 10 postirradiation steps. GRS recommends the use of LWR fuels based on oxygen and on the main HAMMER isotopes 235-U, 236-U, 238-U, 237-NP, 238-PU, 239-PU, 240-PU, 241-PU, 242-PU, 241-AM and 243-AM. Gadolinium entries should be handled with care if singular positions of GD-rods in real assemblies are found.
Other mixture entries at start of calculation should only be impurities.  Cladding should be ZR, AL or stainless steel.  Special options for handling other materials can be found in the user description.  Activation of structure materials is not calculated.  Strong heterogeneous assembly problems outside of the input data processor should be precalculated by using more-dimensional codes to achieve a neutron spectra equivalent HAMMER lattice (FEC-method).  Coolant pressure, coolant temperatures and coolant steam contents are assumed to be constant during burnup.  During each program loop neutron spectra and cross sections are assumed to be constant.

6. TYPICAL RUNNING TIME:  Ca. 1 minute.

7. UNUSUAL FEATURES OF THE PROGRAM

OREST96, written for practical application, can easily be started with an appropriate input data processor, generating fully automated program loops. Time-dependent  boron concentrations may be used. Important isotopes for capture and fission reactions are analyzed. Problem-dependent rod temperatures, neutron multiplication factors and spectra, number of  neutrons and recoverable thermal energies per fission, and cross sections in one-group structure are generated during each run.
Updated and tested HAMMER-ORIGEN-libraries without adjusted data are used (see references); additional external libraries are not needed. Short running times are achieved with compressed nuclear libraries. Decay heat problems can also be solved for short time periods.
Reactivity neutron balance is calculated in order to check for fuel burnup.
OREST96 results can be saved for additional calculations (shielding, reprocessing simulations, tape backup).

8. RELATED AND AUXILIARY PROGRAMS

The GRS-updated library generation system LITHELP for the THERMOS library and for the HAMLET library is used for processing the binary HAMMER libraries.

10. REFERENCES

- Suich, J.E., and H.C. Honeck:
The HAMMER-System - Heterogeneous Analysis by Multigroup Methods
of Exponentials and Reactors
TID-4500, U.S. Department of Energy (January 1967).
- M.J. Bell:
ORIGEN - The ORNL Isotope Generation and Depletion Code
ORNL-4628, UC-32-Mathematics and Computers (May 1973).
- Cross Section DATA/ENDF-B-V
Summary of ENDF/B-V-Data for Fission Products and Actinides
NP-3787 Final Report (1984).
(LWR-weighted cross sections and other nuclide properties for
reaction and decay)
- E. Brown and R.B. Firestone:
Table of Radioactive Isotopes
Lawrence Berkeley Laboratory, John Wiley and Sons, New York (1986)      (decay energies and gammaline spectra)
- J.A. Buchholz et al.:
SCALE - A Modular Code System for Performing Standardized Computer     Analysis for Licensing Evaluation
NUREG/CR-0200 (August 1980).
SCALE-Version 3: (remainder of LWR-weighted cross sections, other  nuclide properties for reaction and decay, and gammaline spectra
from libraries of ORIGEN-S)
- B.F. Rider:
Compilation of Fission Product Yields
Vallecitos Nuclear Center
NEDO-12154-3 (C) (October 31, 1981).
(fission yields including 241-PU)
- U.Hesse
Verifikation des programmsystems OREST (HAMMER-ORIGEN) an den Nachbestrahlungsanalysen von Mischoxidbrennstoff des Reaktors Obrigheim
BMU-1986-116, September 1986.
- U.Hesse
Verifikation des programmsystems OREST (HAMMER-ORIGEN) an den Nachbestrahlungsanalysen der Brennelemente BE-168, 1870, 171 und 176 des Reaktors Obrigheim.
BMU-1986-117, September 1986
- M.D.DeHart, M.C.Brady, C.V.Parks
OECD/NEA Burnup Credit Calculational Criticality Benchmark Phase I-B Results,
NEA/NSC/DOC(96)-06, ORNL-6901, June 1996
- Summary of ENDF/B-V-Data for fission Products and Actinides,
NP-3787, Final Report 1984
- M.Clemente, U.Hesse, S.Langenbuch, W.Zwermann
Einsatz von MOX-Brennelementen in LWR, GRS-A-2012
Februar 1993
- U.Hesse
OREST - The HAMMER-ORIGEN Burnup Program System : Method and Results, Nuclear Technology,
Vol.82, August 1988.
- AEN/NEA JEF Report 14,
Table of simple Integral Neutron Cross Section Data from JEF-2.2, ENDF/B-VI, JENDL-3.2, BROND-2 and CEND-2, OECD 1994.
- S.F.Mughabghab
Neutron Resonance Parameters and Thermal Cross Sections
Brookhaven National Laboratory, Upton New York
Academic Press, INC., 1984, Vol.1
- U.Hesse, W.Denk, H.Deitenbeck;
OREST - eine direkte Kopplung von HAMMER und ORIGEN zur Abbrandsimulation von LWR-Brennstoffen,
GRS-63, November 1986
- U.Hesse, H.Deitenbeck,
OREST-94, User-Instruction, Gesellschaft fur Anlagen und Reaktorsicherheit
(GRS) mbH, 1.Februar 1995

- U.Hesse, J.Sieberer:
USER-INSTRUCTION
6th July 1999

11. MACHINE REQUIREMENTS:  A clock is needed. 32MB CPU storage are needed.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:  Dec Unix

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:  None

15. NAME AND ESTABLISHMENT OF AUTHORS

          Ulrich Hesse, Johann Sieberer
          Waste Management Division
          Gesellschaft fuer Reaktorsicherheit mbh (GRS)
          Forschungsgelaende
          8036 Garching, Federal Republic of Germany

Input Directory
Library Directory
Printout Directory. Printouts of sample problems
Source Directory for LITHELP
Source Directory for OREST96
Temporary Directory
lithelp96.sh. Shell script to start library generation for HAMMER
Documentation in electronic form