PCTRAN/CND: Personal Computer Program for Predicting CANDU Reactor Thermalhydraulics

Abstract

Computer simulation codes are required to simulate accident induced nuclear reactor system transients. The prime objective of such simulations is to predict the thermohydraulic characteristics of the reactor system during an anticipated system transient. Canadian codes SOPHT [I] and FIREBIRD [2] are currently used to simulate thermohydraulic transient in CANDU reactor systems. These codes involve extensive modelling of the CANDU system, enormous computing time and are expensive to run. This paper deals with the development of the personal computer program PCTRAN/CND for predicting the CANDU thermohydraulics. This program is an extension of the software package PCTRAN developed by Po [3] that can simulate a variety of accident and transient conditions for nuclear power plants. This version operates on an IBM personal computer IBM-PC (or compatible). The mathematical formulation of this digital computer model is based on mass, momentum and energy balances applied to the fluid control volume representing the different components of the CANDU reactor. The majority of the nuclear reactor transient complicated phenomena are simulated at no computing cost. These phenomena are small, large break LOCA, natural circulation, steam generator tube rupture, steam line break, feedwater transient, and normal operation/reactor trip. Extensive validation runs of this program showed a fair agreement between the program predictions and plant data.