SOLVING OF TASKS ON NONDESTRUCTIVE INSPECTION OF NUCLEAR REACTOR FUEL

Elaboration of nondestructive methods to define fissile material composition was started at Radium Institute in 1973. In that period nuclear industry was lacking of such methods.

Methods and equipment for nondestructive inspection of burn-up and nuclide composition of both spent and fresh nuclear fuel for NPPs and RosAtom enterprises are being developed and improved at the Laboratory also at the present time.

In order to determine fuel burn-up and composition in heat-producing assemblies for WWER and RBMK reactors by means of nondestructive methods, scan type installations are developed at Novovoronezh and Leningrad base nuclear-power plants and fabricated together with NPPs' crews. Measurements can be carried out by four methods:

• according to ¹³⁴Cs to ¹³⁷Cs activity ratio;
• according to ¹³⁷Cs content;
• according to specific neutron outflow;
• according to specific gamma-quantum outflow.

Adjustment of methods and equipment is realized at laboratory benches, which serve as prototypes of installations created at NPPs and enterprises of nuclear fuel cycle.

Nuclear fuel examination bench (SKAT) destined for adjustment of methods of nuclear fuel burn-up nondestructive analysis