Heat transfer analysis of the pressure vessel steel irradiation capsules in the Oak Ridge Research Reactor-Pressure Vessel Benchmark Facility

The purpose of this study was to determine a design for irradiation capsules for the Light Water Reactor (LWR) Pressure Vessel (PV) Wall Simulation experiment in the Poolside Facility (PSF) of the Oak Ridge Research Reactor (ORR). The experiment structural configuration is based on the actual configuration of an LWR PV wall, the surveillance specimen capsule, and the thermal shield. The design temperature at which the metallurgical test specimens are to be maintained in the experiment is based on the operating temperature of an LWR PV of 288°C.

A detailed investigation of the thermal behavior of the proposed design configuration was performed in order to arrive at an "optimum flexibility" design that will ensure a uniform temperature distribution of 288°C ± 10°C for all the test specimens while allowing for uncertainties in nuclear heating rates in the iron, thermal behavior and component dependability.

The conclusions of these studies determined the final design parameters for these irradiation capsules. Currently the experiment is operating within the specified design criteria.