1. NAME AND TITLE

BURP2: Calculation of Buildup and Decay of Radioactive Fission Products.

2. CONTRIBUTOR

Babcock and Wilcox, Atomic Energy Division, Lynchburg, Virginia.

3. CODING LANGUAGE AND COMPUTER

FORTRAN IV; CDC 6600.

4. NATURE OF PROBLEM SOLVED

BURP2 calculates the activity of 237 radioactive fission products for up to 100 consecutive reactor operating and shutdown times. Fission products can be allowed to leak from the fuel at any specified rate. The activity of each nuclide is calculated in the fuel, coolant, and purification filter system. The total gamma-ray source strengths are calculated at each time step in the core, coolant, and purification filter system. For each time step, new values may be assigned to the reactor power, thermal neutron flux, fraction of the total fissions due to one or two fissioning isotopes, and the coolant and filter cleanup rates. The user must assign a filter purification efficiency, a fuel leak rate and a plate out rate for each fission product. Removal of fission products by neutron absorption is included in the fuel but not in the coolant or filter. The activated fission product is not returned to the fuel. Activation of structural materials is not considered. The user has the option of saving his data on tape for further processing.

5. METHOD OF SOLUTION

BURP2 obtains the analytical solution of up to 5 coupled differential equations describing the buildup and loss of radioactive fission products in a nuclear fuel or reactor system. The fission product concentration obtained from these equations is used to calculate activities and gamma-ray source strength. Gamma ray yields for six energy groups; fission yields for ²³⁵U; ²³⁹Pu, and ²³⁸U; thermal absorption cross sections; branching fractions; and decay constants are internally stored in the program.

6. RESTRICTIONS OR LIMITATIONS

Parameters are limited as follows: number of purification and leak rate tables ^nu24u 5, number of time steps < 100, number of photon energy groups = 6.

7. TYPICAL RUNNING TIME

No study has been made by RSIC of typical running times for BURP2.

8. COMPUTER HARDWARE REQUIREMENTS

BURP2 is operable on the CDC 6600 computer.

9. COMPUTER SOFTWARE REQUIREMENTS

A FORTRAN IV compiler is required.

10. REFERENCE

J. B. Perry and J. M. Alcorn, "BURPA Computer Program for Calculating Buildup and Decay of Radioactive Fission Products," Informal Notes (November 1966).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source code and sample problem input and output.

12. DATE OF ABSTRACT

May 1974; updated August 1975.