1. NAME AND TITLE

PREST: Calculator of Pressure and Temperature Transient in Containment Studies.

2. CONTRIBUTOR

European Atomic Energy Community, EURATOM, through the OECD NEA Data Bank, Gif-sur-Yvette, France.

3. CODING LANGUAGE AND COMPUTER

Fortran IV; IBM 360-370.

4. NATURE OF PROBLEM SOLVED

PREST determines transient pressure and temperature inside the containment building following a loss-of-coolant accident due to a rupture in the primary cooling system of a nuclear power plant having water as the primary coolant. The model includes the calculation of the radiation doses incurred to the thyroid due to inhalation of radioactive iodine released outside the containment building.

The mathematical model adopted allows both the blowdown phase of the primary coolant and the subsequent phase of the accident to be studied. The program may account for the presence of the consequence-limiting engineered safeguards, such as internal and/or external Spray Systems.

5. METHOD OF SOLUTION

The energy equation is solved at each time step by using the Newton Method. In order to determine the heat exchange with structures inside the containment building as well as with the outside atmosphere, the structures are treated in slab geometry. The resulting Fourier equations for heat conduction are solved numerically by using an implicit form to avoid stability problems. Plots of pressure, temperature, and integrated dose-rate versus time may be obtained by means of the Calcomp Device.

6. RESTRICTIONS OR LIMITATIONS

Maximum number of internal slabs 6

Maximum number of external slabs 4

Maximum number of meshes in each slab 100

7. TYPICAL RUNNING TIME

PREST requires about 10 minutes of running time for a typical 24-hour transient.

8. COMPUTER HARDWARE REQUIREMENTS

PREST is operable on the IBM 360/370 computers.

9. COMPUTER SOFTWARE REQUIREMENTS

A Fortran IV compiler is required. The code is executed under the IBM 360/65 operating system.

10. REFERENCE

G. Gaggero, P. M. Gerini, G. Leoni, and J. B. van Erp, "MACACO-PREST, An Analog Model and a Digital Code for Containment Studies," EUR 3927.e (1968).

11. CONTENTS OF CODE PACKAGE

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

12. DATE OF ABSTRACT

January 1982.