Summary of Recent Results from the Jaeri/U.S. Fusion Neutronics Phase I Experiments

Abstract

The tritium breeding ratio (TBR) in a fusion blanket is one of the most important parameters to be considered in the conceptual design of fuel-self-feeding deuterium-tritium (D-T) reactors. There are many factors, both physics and engineering, that affect the TBR value in a design. Efforts in the neutronics area are to provide data needed for identifying and selecting materials and configurations that achieve an optimal TBR, and to improve the accuracy of neutronics predictions. A program is in progress on integral neutronics experiments and their analyses in the collaboration between the Japan Atomic Energy Research Institute (JAERI) and the US Dept. of Energy. In the phase I experiments, a simplified blanket test module of Li/sub 2/O is set at a portion of an enclosure with a 14-MeV point neutron source at its center. The test module is composed of unit size blocks and is able to mock up the complexity of radial configurations of various blanket concepts in full size. Neutronic quantities are measured along the central axis of the module. Main concerns are the tritium production rate (TPR) and the neutron spectrum. New measuring techniques have been developed to meet the requirements of this program in both on-line typemore » and time-integrated type measurements.« less