| 摘要 |
<p>PURPOSE:To reduce radioactive damage to a radiation detector, and to easily calibrate the radiation detector without removal of radioactive contamination. CONSTITUTION:A burn-up measuring device for measuring a burn-up of a used nuclear fuel 2 to be measured, submerged at a predetermined position in water, with the use of radioactive radiation, incorporates a detector guide pipe 11 having one end which is closed, and the other end which is opened, and which is exposed above the water surface. Further, it comprises a radiation detector 4 movably introduced in the detector guide pipe 11 from the opened end, and attached at a regulated position in the guide pipe, for detecting a radioactive radiation from the used nuclear fuel 2, and a measuring device 6 for carrying out a predetermined process in accordance with a detection signal from the detector 4 so as to measure a burn-up of the used nuclear fuel.</p> |
