RSICC CODE PACKAGE CCC-839

1.         NAME AND TITLE

MEGA

2.         CONTRIBUTOR

KAERI (Korea Atomic Energy Institute), Daejeon, South Korea, through the OECD NEA Data Bank, Boulogne-Billancourt, France.

3.         CODING LANGUAGE AND COMPUTER

Fortran source code and Perl scripting (C839MNYCP00).

4.         NATURE OF PROBLEM SOLVED

MEGA is a mechanistic and engineering fission gas release prediction model for UO2 fuel. It is based upon the diffusional release of fission gases from inside the grain to the grain boundary, and the release of fission gases from the grain boundary to the external surface by an interconnection of the fission gas bubbles in the grain boundary. The capability of the MEGA model was validated by a comparison with the fission gas release data base and sensitivity analyses of the parameters. It was found that the MEGA model could correctly predict the fission gas release in the broad range of a fuel burnup up to 98 MWd/kgU. Especially, the enhancement of fission gas release in a high burnup fuel, and the reduction of fission gas release at a high burnup by increasing the UO2 grain size are found to be correctly predicted by the MEGA model.

5.         METHOD OF SOLUTION

MEGA solves numerically the time and space-dependent differential equations.

 

6.         RESTRICTIONS OR LIMITATIONS

None stated.

7.         TYPICAL RUNNING TIME

Input file dependent, generally a few seconds.

8.         COMPUTER HARDWARE REQUIREMENTS

Minimal

9.         COMPUTER SOFTWARE REQUIREMENTS

Fortran compliant compiler.

10.        REFERENCES

Documentation included in package:

Jin-Sik Cheon an Chan Bock Lee: How to make MEGA executable with CVF and ifort, KAERI, 2015/11

Chan Bock LEE, Yong Sik YANG, Dae Ho KIM, Sun Ki KIM and Je Geun BANG, A New Mechanistic and Engineering Fission Gas Release Model for a Uranium Dioxide Fuel”, Journal of NUCLEAR SCIENCE and TECHNOLOGY, Vol. 45, No. 1, p. 60–71, 2008.

11.        CONTENTS OF CODE PACKAGE

Included in CD distribution are documents, Fortran source, data files, and Windows executable. (C839MNYCP00)

12.        DATE OF ABSTRACT

July 2016

KEYWORDS:RADIOACTIVITY RELEASE; FISSION PRODUCTS