Irradiation of Be12Cr Under Reactor Conditions at Specified Temperature-Dose Regimes

Abstract

This work is dedicated to studying the properties of chromium beryllide (Be₁₂Cr), a promising neutron multiplier material for the blankets of future fusion reactors. As is known, the operation of fusion reactor blanket materials is characterized by high temperatures and radiation, which makes radiation resistance a primary requirement for such materials. The relevance of this work is driven by the need to conduct reactor tests of Be₁₂Cr samples manufactured by the hot vacuum pressing method. The aim of the study is to substantiate safety and determine the temperature-dose irradiation regimes at the WWR-K research reactor. The research methodology is based on coupled numerical modeling: neutron-physical analysis using the Monte Carlo method in MCNP 6 and thermophysical calculations using computational fluid dynamics methods in ANSYS Fluent 2024 R1.

As a result, detailed distributions of neutron fluxes, energy release fields, and temperatures were obtained. It was established that the dose accumulated over 6 irradiation cycles reaches 0.14 dpa. Thermophysical analysis showed that with a change in helium pressure in the range of 10–101325 Pa, the volume-averaged temperature of the samples varies in the range of 157–428 °C for the lower position and 135–499 °C for the upper position, respectively. Analysis of the data revealed a temperature inversion effect: at a pressure of 10 Pa, the temperature of the upper samples is 71 °C higher than that of the lower ones due to a change in the nature of heat transfer in the system. The scientific value of the research lies in obtaining the first set of calculated data for a specially developed irradiation device designed for the reactor irradiation of chromium beryllide samples. The practical significance of the work consists in the creation of a verified tool for predictive analysis and planning of long-term reactor tests of Be₁₂Cr samples, ensuring compliance with the thermophysical safety limits of the experiment under WWR-K reactor conditions at specified temperature-dose regimes.