| 摘要 |
PURPOSE:To measure specific radioactivity of the entire container accurately, by placing a ray source for measuring self-shielding effect in the container to correct the self-shielding effect from the difference in the intensity of the radiation depending on the presence of waste. CONSTITUTION:A measuring container 1 in which a ray source 7 for measuring self-shielding effect is placed is filled with a metal waste and moved to a measuring device 2. The measuring device 2 measures the weight of the metal waste with a load cell 4 and the intensity of radiation from the metal waste and that from the ray source 7 are measured with radiation measuring devices 5 and 6. The relationship which was previously determined between the level of radioactivity and the intensity of radiation when radioactive substance exists evenly in the measuring container 1 is compared with the measured values of the measuring devices 5 and 6 thereby enabling the level of radioactivity of the metal without self-shielding. Thus, the results are multiplied by the shielding effect due to the metal waste and divided by the weight of the metal waste thereby enabling the evaluation of the specific radioactivity of the metal waste in the measuring container 1.
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