The use of concrete for shielding high-temperature reactors

The possibility is examined of constructing thermal shields of reactors from chromite and fireclay heat-resistant concretes. Neutron fluxes of different intensities (up to 10¹³ n/cm² sec, close in spectrum to the fission spectrum) absorbed by shields of these materials are examined. The passage of neutrons, y-ray fluxes and generation of heat in the shield are taken into account. The temperatures in the shield are calculated for different neutron fluxes, thicknesses of concrete and cooling conditions. A static calculation of the temperature stresses in a shield constructed from heat-proof reinforced concrete is carried out.

It is established that heat-resistant reinforced concrete can be used for the shields of nuclear reactors for neutron fluxes to the concrete up to 10¹³ n/cm² sec, temperatures up to 1000–1100°C and temperature drops of up to 900°C.