No abstract

This report was prepared as an account of work sponsored by the United States Goverllment. Neither the United States nor the Department of Energy. nor any of their employe es. nor dny of their contractors. subcontractors. or their employees. makes any warranty. express or implied, or ass u mes any legal liability or responsibili ty for the accuracy. completeness or usefulness of any information, apparatus. product or process disclosed. or represents that its use would not infringe privately owned rights. The views. opinions and conclusions contained in this report are those of the contractor and do not necessarily represent those of the United States Government or the United States Department of Energy.

No abstract

A finite difference computer code, named HYDRA-I, has been developed to simulate the three-dimensional performance of a spent fuel assembly contained within a cylindrical canister. The code accounts for the coupled heat transfer modes of conduction, convection, and radiation and permits spatially varying boundary conditions, thermophysical properties, and power generation rates. This document is intended as a manual for potential users of HYDRA-I. A brief discussion of the governing equations, the solution technique, and a detailed description of how to set up and execute a problem is presented. HYDRA-I is designed for operation on a CDC 7600 computer. An appendix is included that summarizes approximately two dozen different cases that have been examined. The cases encompass variations in fuel assembly and canister configurations, power generation ratEs, filler materials, and gases. The results presented show maximum and various local temperatures and heat fluxes illustrating the changing importance of the three heat transfer modes. Finally, the need for comparison with experi-Inental data is emphasized as an aid in code verification although the limited data available indicate excellent agreement. iii SUMMARY A finite difference computer code, named HYDRA-I, has been developed to simulate the three-dimensional thermohydraulic performance of a spent fuel assembly contained within a vertical cylindrical canister. The code accounts for the coupled heat transfer modes of conduction, convection, and radiation and permits spatially varying boundary conditions, thermophysical properties, and power generation rates. This document is intended as a manual for potential users of HYDRA-I. A brief discussion of the governing equations, the solution technique, and a detailed description of how to set up and execute a problem is oresented. This documented version of HYDRA-I is "intended primarily for the simulation of steady-state conditions within those fuel assembly/canister configurations considered most likely to be of current interest. The code, in its present form, is restricted to fuel assemblies that have an odd number of rods and models one quadrant of the canister with a 45° line of symmetry. The above restrictions can be removed, but their implementation is not described in this document. HYDRA-I is designed for operation on a CDC 7600 computer. An appendix is included that summarizes approximately two dozen different cases that have been examined. The cases encompass variations in fuel assembly and canister configurations, power generation rates, filler materials, and gases. The results presented show maximum and various local temperatures and heat fluxes illustrating the changing importance of the three heat transfer modes. Finally, the need for comparison with experimental data is emphasized as an aid in code verification although the limited data available indicate excellent agreement. v CONTENTS ABSTRACT SUMMARY 1.0 INTRODUCTION 2.0 GOVERNING EQUATIONS 2.1 CONSERVATION OF MOMENTUM 2.1.1 Discrete Form of the Mom...

No abstract