PLUTONIUM (PU) ACCOUNTING SYSTEM AND METHOD FOR PYROPROCESSING OUTPUT MATERIAL OF U/TRU (URANIUM/TRANSURANIUM) INGOT

摘要

The present invention relates to a plutonium (Pu) accounting system for measuring plutonium in an uranium/transuranium (U/TRU) ingot, which is an output material from pyroprocessing, and to a measurement method thereof. More specifically, a system for measuring plutonium contained in an U/TRU ingot, which is an output material from pyroprocessing, by measuring energy multiplication of fast induced fission neutron occurring in the U/TRU ingot, which comprises: a cylindrical body (10) having an opening on the top thereof; the U/TRU ingot (1) disposed in a space unit (20) formed inside the body (10); one or more inner detecting units (110) disposed at predetermined intervals from the outer diameter of the space unit (20) to detect neutrons emitted from the U/TRU ingot (1); one or more outer detecting units (120) disposed at predetermined intervals from the inner diameter of the body (10) to detect the neutrons emitted from the U/TRU ingot (1); a neutron measuring device (100) including a neutron moderator (130) filling the inside of the body (10) to reduce the speed of fast neutrons; and a Pu measuring unit (200) calculating a ratio of neutron signals through the neutrons detected by the inner detecting unit (110) and the outer detecting unit (120), and determining average neutron energy using the calculated ratio of neutron signals to determine the amount of plutonium in the U/TRU ingot (1).