Year
2013
Abstract
A development program of gamma-ray nondestructive assay for nuclear material has been launched at Japan Atomic Energy Agency (JAEA). The NDA system utilizes a laser Compton scattered (LCS) gamma-ray source and nuclear resonance fluorescence (NRF). In the program, we are aiming at demonstration of high-flux gamma-ray generation via laser Compton scattering and design of NDA systems for the measurement of fissile materials in melted nuclear fuels at Fukushima Daiichi Nuclear Power Station and other nuclear security and nuclear safeguards applications. The gamma-ray generation is planned to be demonstrated at a test facility of the energy-recovery linac, the Compact ERL (cERL), at KEK. The construction of the cERL is ongoing as scheduled and the electron gun and superconducting accelerators have been installed. The commissioning of the cERL will be started from April, 2013 and the gamma-ray generation experiment is scheduled in 2014 (JPFY). The cERL is designed to produce an electron beam of small emittance and high average current suited for LCS gamma-ray generation. A high-power mode-locked laser and a laser enhancement cavity to realize high-density laser photons at the LCS collision spot are under development in collaboration with Kansai Photon Science Institute JAEA, KEK and Hiroshima University. The NDA system for Fukushima melted fuels must be designed to mitigate highly radioactivity of debris, which may cause large background signals in NRF measurements. We are proposing NDA systems based on different methods: resonance scattering, resonance transmission, integral resonance transmission and photo-fission. We are developing a Monte Carlo simulation code, NRFGeant4, to evaluate the performance of these measurement methods. A benchmarking study of NRFGeant4 and MCNP-X is in progress under a collaboration program between JAEA and US-DOE. We present status of the above R&D’s in detail.