Development of Neutron Detection Module of Unified Non-Destructive Assay System for Pyroprocessing Facility Safeguards

Year
2013
Author(s)
Dae Yong Song - Korea Atomic Energy Research Institute
Dong Young Kim - Korea Atomic Energy Research Institute
S.Y. Lee - Korea Atomic Energy Research Institute
S. H. Park - Korea Atomic Energy Research Institute
Hee-Sung Shin - Korea Atomic Energy Agency
Hee Seo - Korea Atomic Energy Research Institute
Sang-Ho Na - Korea Atomic Energy Research Institute
Abstract
The Korea Atomic Energy Research Institute (KAERI) has made an effort to develop a pyroprocessing technology to resolve an on-going problem in Korea, i.e., the management of spent nuclear fuels. To this end, a test-bed facility for pyroprocessing, called PRIDE (PyRoprocessing Integrated inactive DEmonstration facility), is being constructed at KAERI. The main objective of PRIDE is to evaluate the performance of unit processes, remote operation, maintenance, and proliferation resistance. In addition, integrating all unit processes into a onestep process is also one of the main goals. PRIDE can also provide a good opportunity to test safeguards instrumentations for a pyroprocessing facility such as nuclear material accounting device, surveillance system, radiation monitoring system, and process monitoring system. In the present study, a non-destructive assay (NDA) system for the test of nuclear material accountancy of PRIDE was designed by integrating three different NDA techniques, i.e., neutron, gamma-ray, and mass measurement. The developed neutron detection module consists of 56 3He tubes and 16 AMPTEK A111 signal processing circuits. The amplifiers were matched in terms of the gain and showed good uniformity after gain matching procedure (%RSD=0.37%). The axial and radial efficiency distribution within the cavity was then measured using 252Cf neutron source and compared with the MCNPX calculation results. The measured efficiency distributions were well agreed with calculations.