Biological shielding calculation of the UCN super-source on the WWR-M reactor

The design and calculation of biological shielding at the output of the UCN source on superfluid helium for the WWR-M reactor was carried out. The configuration of the casemate - biological protection around the thermal column splitter is calculated. The calculation takes into account the flux density, the spectrum and the angular divergence of the neutron beam at the exit of the intercanal part of the UCN source, as well as the geometry and material composition of the elements inside the casemate. For layered protection made of steel, polyethylene and lead, the protection thickness varies from 85 cm to 92 cm. The maximum calculated dose rate for neutrons and gammas on the surface of the casemate does not exceed 1 mrem/h. With the maximum permissible dose rate (PDR) for the group A personnel - 1.2 mrem/h, the casemate design of the UCN source ensures the safe operation of the source. The calculation was carried out by the Monte Carlo method within the SCALE-6.2 complex using the MAVRIC program.