1. NAME AND TITLE OF DATA LIBRARY

MATXS70-JEF87: JEF/EFF Based 70 Group Neutron Data Library in MATXS Format.

2. NAME AND TITLE OF DATA RETRIEVAL PROGRAMS

BBC Computer Code for Converting Library to Binary Form.

3. CONTRIBUTORS

Swiss Federal Institute For Reactor Research, Würenlingen, Switzerland, through NEA Data Bank, Gif-sur-Yvette Cedex, France.

4. HISTORICAL BACKGROUND AND INFORMATION

The Joint European File (JEF) is a computer-readable repository of neutron and photon data in the energy range up to 20 MeV. Together with the recently evaluated fusion file (EFF), it is rapidly becoming the standard European data source for thermal reactors, fast reactors, fusion, shielding and controlled thermonuclear analysis. JEF is administered by the Nuclear Energy Agency (NEA Data Bank). The file has evolved through several updates, the current one being called JEF-1.

Discrete ordinate transport codes that solve the Boltzmann equation for the distribution of neutrons and photons in nuclear systems have reached a high level of development. Major users of these codes demand up-to-date, documented cross section data as input. Therefore, new multigroup nuclear data libraries based on JEF/EFF were generated for general applications. For this purpose, the NJOY (6/83) nuclear data processing system was used.

5. APPLICATION OF THE DATA

The cross section libraries can be read into the codes TRANSX-CTR (PSR-206) or TRAMIX. These are codes which read nuclear data from a MATXS library and produce problem specific transport tables compatible with many discrete ordinates and diffusion codes.

6. SOURCE AND SCOPE OF DATA

The 70-group WIMS-BOXER GENDF library contains P1 neutron data pertaining to 100 JEF-1 nuclides and 19 JEF-1.1 nuclides. The energy structure of the WIMS-BOXER library consists of the standard 69 WIMS structure and one additional group from 10 MeV to 14.918 MeV.

The GENDF format of the 70-group WIMS-BOXER library has been put into the MATXS format. NJOY (6/83) modules have been used to combine the individual isotope GENDF's for all materials and to reformat the resulting GENDF file into MATXS format. The MATXS file is a generalized cross section library in a flexible format similar to the CCCC standard cross section file ISOTXS.

7. DISCUSSION OF THE DATA RETRIEVAL PROGRAM

A computer code, BBC, is included to convert the data library to binary form and vice versa.

8. DATA FORMAT AND COMPUTER

Card images; VAX family of computers. A total of about 28 megabytes of disk storage is required.

9. TYPICAL RUNNING TIME

On the VAX 8810, the library was converted to binary form in 4 minutes, 34 seconds. The conversion from binary to BCD form took 5 minutes and 36 seconds.

10. REFERENCES

a. Included in the package:

P. Vontobel and S. Pelloni, JEF/EFF Based Nuclear Data Libraries, EIR-Bericht Nr. 636, Swiss Federal Institute for Reactor Research, Würenlingen, Switzerland, December 1987.

11. CONTENTS OF PACKAGE

The package contains the reference listed above, the data library and a conversion program. The data library is transmitted on eight DS/HD 5.25-inch diskettes (1.2 mb).

12. DATE OF ABSTRACT

January 1991.