| 摘要 |
<p>PURPOSE:To perform the measurement of a radioactivity level with high accuracy and high efficiency and to minimize the quantity of waste contaminated with radioactivity, by detecting radioactive rays at two or more positions and calculating the difference between the detection valves at said positions. CONSTITUTION:A radiation detector 1 and a radiation detector 2 are respectively arranged at positions separated by distances l1, l2 from the concrete disassembling waste at disassembling work site of a nuclear facility such as an atomic reactor successively carried by a belt conveyor 4. The count values of the detectors 1, 2 respectively consist of the contribution part due to the concrete disassembling waste 3 and that due to a background but, by calculating the difference between the count values of the detectors 1, 2, the contribution part from the concrete disassembling waste 3, that is, a radioactivity level can be known regardless of the contribution parts due to the background.</p> |
