Development and upgradation of a neutron Well Coincidence Counter for Radio Metallurgy Division

摘要

A neutron well coincidence counter (NWCC) was developed for the nondestructive assay of plutonium in fuel materials and nuclear waste in Radio metallurgy Division, The doubly sealed waste packets are stored in 18.5 litre metal containers (28 cm dia x 30 cm height). The waste containers are to be routinely monitored to verify that the plutonium content is below the limits prescribed for safe disposal of the nuclear waste. Maximization of the neutron detection efficiency, flat response (+ - 5 percent) over the active volume of the waste container and minimization of response to ambient neutrons has been achieved in the design of the NWCC. The size of the well (30 cm Dia x 40 cm height) was optimized for comfortable positioning of the waste containers for routine assay. Twelve ~3He neutron proportional counters (25.4 mm Dia x 45cm sensitive length, 4 atm. fill pressure and sensitivity of 65 cpsv) were used for thermal neutron detection.