1. NAME AND TITLE
EASY 4.1: A Multipurpose Activation and Transmutation Code System.
2. CONTRIBUTOR
UKAEA, Culham, Abingdon, Oxfordshire, United Kingdom.
3. CODING LANGUAGE AND COMPUTER
FORTRAN 77 and C; UNIX (C00662/MYWS/00).
4. NATURE OF PROBLEM SOLVED
The European Activation System (EASY) is a complete tool for the calculation of activation in materials exposed to neutrons. It can be used for any application (fusion, transmutation, fission and accelerator) where the neutron energy does not exceed 20 MeV. EASY-4.1 consists of the inventory code FISPACT-4.10 and the FENDL-2.0 activation file, which contains various libraries of nuclear data. FISPACT is an inventory code that solves a set of stiff 1st order differential equations by means of a numerical method.
The FENDL/A-2.0 library contains 13006 excitations functions involving 739 targets from 1H to 248Cm, in the incident energy range up to 20 MeV. The FENDL/D-2.0 library contains decay data for 1867 nuclides. Uniquely, an uncertainty file, FENDL-2.0_UN is also provided. A set of four different multigroup libraries are provided, available group structures are: WIMS (69), GAM-II (100), XMAS (172) and VITAMIN-J (175). Various choices of micro flux weightings are available for particular application. Other data libraries are included: fission yield, ingestion and inhalation indices, A2 values for the transport of radioactive material. Particle emission spectra, stopping power and cross sections libraries for alpha, deuteron, helium, proton and triton allow secondary charge particle activation contributions to be calculated. Special features: uncertainties, pathways analysis, sequential charge particle contributions, pulses or continuous irradiation, gas production (as daughter and emitted particle).
5. METHOD OF SOLUTION
The basic equations solved by the FISPACT code are those giving the rate of change of nuclide number density with time: the Batemen equation. The method of solution used is basically that of Sidell, that is a numerical solution. The number densities are calculated by the Taylor series expansion in a modified form.
6. RESTRICTIONS OR LIMITATIONS
Having a numerical solver there is no restriction but the limitations imposed by the nuclear data made available to the solver. The convergence of the solution is checked regularly and tested against internal and user defined limits.
7. TYPICAL RUNNING TIME
Running time are rather platforms dependent but, typically, span from tenth to hundreds of sections.
8. COMPUTER HARDWARE REQUIREMENTS
UNIX workstation: IBM RS/6000, IBM SP2, SUN, HP, DEC ALPHA.
9. COMPUTER SOFTWARE REQUIREMENTS
FORTRAN and C compilers are required to build executables. Visual Numerics PV-WAVEŽ visualization software is optional. At RSICC the system was tested on the following machines:
IBM RS/6000 Model 590 running Aix 4.2 with XLF Version 3.2.2.
HP/9000 Model 715 running HPUX-10.20 with f77 version 10.20.01.
Dec Alpha 3000 running DEC OSF/1 3.2 with Dec Fortran 90 4.2.
10. REFERENCES
a: Included in the document:
J-Ch. Sublet, "EASY-4.1 README File" (hard and electronic copy) (February 1998).
R. A. Forrest and J-Ch. Sublet, "FISPACT 4 User Manual, UKAEA FUS 287 (hard and electronic copy) (April 1995).
"Atlas of Neutron Capture Cross Sections," INDC(NDS)-362 (electronic copy only) (April 1997).
b: Background information:
"FENDL/A-2.0" IAEA-NDS-173 (draft March 1997).
11. CONTENTS OF CODE PACKAGE
Included are the referenced documents in (10.a) and a CD-ROM with a compressed Unix tar file which contains scripts, source files, test cases, data libraries and documentation files.
12. DATE OF ABSTRACT
December 1998.
KEYWORDS: ACTIVATION; CTR; ISOTOPE INVENTORY; WORKSTATION