METHOD AND DEVICE FOR CONTROLLING RADIATION DAMAGE OF MATERIAL OF CASING OF WATER-WATER REACTOR Russian patent published in 1998 - IPC

FIELD: radiation material engineering. SUBSTANCE: invention focuses on material damage under hot-neutron irradiation. To increase resource of irradiated materials, the latter are submitted to radiation annealing by irradiating them with 0.2 MeV gamma-ray beam while maintaining temperature of material below thermal annealing level using simultaneous additional heat removal from materials under irradiation. To decrease radiation damage, screens effectively absorbing gamma-rays are placed between hot-neutron source and material being irradiated. Simultaneously, gamma-emission intensity range is varied from $$$ to $$$ depending on purpose of control, type of material under irradiation, and neutron irradiation conditions. According to invention, in radiation damage control device containing nuclear reactor casing, active zone, and screens between them, material of these screens is replaced by water to reduce absorption of gamma-rays of active zone reaching the casing or isotopes or their compounds efficiently converting hot neutrons into gamma radiation. To control radiation damage, proportion of flaxes of neutron and gamma radiations is optimized by means of varying geometrical dimensions of reactor. EFFECT: increased lifetime of materials. 7 cl, 6 dwg, 3 tbl