Evaluation of Thermal Devices for Detecting In-Vessel Coolant Levels in PWRs.

摘要

Thermal sensors proposed for use in pressurized-water reactor (PWR) vessels were tested and evaluated. The thermal devices tested use pairs of K-type thermocouples or resistance temperature detectors to sense the cooling capacity of the medium surrounding the device. One sensor of the pair is heated by an electric current, while the unheated one senses the ambient fluid temperature. The temperature difference between the heated and unheated sensors provides an indication of the cooling capacity of the surrounding fluid. Experiments that simulated the thermal-hydraulic conditions of a postulated PWR loss-of-coolant accident (LOCA) were run, including both natural- and forced-convection two-phase flow tests.