| 摘要 |
PURPOSE:To shorten the time for measurement by impulsively executing the release of radiations from an external radiation source, measuring the radiations released from the inside of a vessel by a piece-by-piece pulse mode and measuring the radiations transmitted through the vessel from the gross integrated quantity by current mode. CONSTITUTION:The external X-rays 2a transmitted through the waste vessel 1 and the internal X-rays 2b radiated from the inside of the vessel 1 are converted 20 to light. The signal occurring in the X-rays 2a is sent via a photo multiplier 21 and selection switches 22a, 22b to a pulse height detector 60 by the current mode. The output signal occurring in an amplifier 50 is passed through a linear amplifier 51 and a multiple pulse height analyzer 52 and the intensity thereof is determined by nuclides in an internal radiation evaluating device 53. The intensity is sent to a radioactivity quantity evaluating device 100. On the other hand, the output of the detector 60 is subjected to A/D conversion 61 and the coefft. of radiation absorption is determined in an external radiation evaluating device 62 and is sent to the device 100. The distribution of the coefft. of radiation absorption in the vessel 1 is calculated in accordance with the output of the device 62 in the device 100. The radioactivity quantity of respective nuclides in the vessel is calculated from the result thereof and the output of the device 53. |
