Development of active nondestructive assay technique by photon interrogation for uranium bearing waste. (1) Development of code system for conceptual design study of assay system

A conceptual design study has been carried out in JAERI on an active nondestructive assay system by photon interrogation for uranium bearing waste. In this system, the uranium is detected by counting photoneutrons of a photonuclear reaction of uranium. This design study needs a coupled neutron/photon transport code which can calculate the photonuclear reaction. In the present work, the continuous energy Monte Carlo transport code MVP which has been developed in JAERI is modified and equipped with the function to calculate the photonuclear reaction and a resultant emission of photoneutrons. A photonuclear cross section library of more than 160 nuclides is also prepared for this code by processing evaluated photonuclear data files. Furthermore, the modified code is verified by analyzing an experiment. (author)