The Phenomenology of the PRT Pump Trip Events

Abstract

A detailed analysis of the PHT pump trip event.s has been performed using the 49 version of SOPHT77, as an assist to the conceptual trip coverage design for Point Lepreau and Gentilly-II. This paper reports on the analysis of the physical phenomena associated with the trip of a PHT pump. It also reports on the simulation of the PHT pump trip test at Point Lepreau, which is used to augment the validation of the model, previously done with commissioning data. The effects of a wide range of parameters, including initial circuit quality, initial reactor power and location of the tripped pump with respect to the pressurizer will be discussed, along with the effects of loop-to-loop interactions. The results of the average channel simulations will show the potential presence of flow instabilities following a single pump trip, whenever void is present in both reactor outlet headers of the affected loop, and stepback and trip are disabled. Since the trip coverage design for the loss of a single PHT pump also caters to the loss of Class IV power, the results of the analysis of the latter will also be discussed, with particular attention to the effects of the secondary side.