RADIOACTIVITY INSPECTION DEVICE AND RADIOACTIVITY DETECTION METHOD

PROBLEM TO BE SOLVED: To provide an accurate and inexpensive radioactivity inspection device and radioactivity inspection method having high detection efficiency, using a plastic scintillation detector.SOLUTION: A radioactivity inspection device comprises: a plastic scintillator 10; a photomultiplier 20; a multichannel analyzer 30; and a computer 40 comprising a region setting unit 41 for setting a channel range for characterizing radioactive cesium as a cesium region and a channel range for characterizing radioactive potassium as a potassium region, a correction factor computing unit 42 for obtaining a correction factor (α=(nk-nb)/(nkk-nbk)), a conversion factor computing unit 43 for obtaining a conversion factor (K=C*W/nth), and a radioactivity quantity computing unit 44 for obtaining a radioactivity quantity (D=nt*K/W') of radioactive cesium per unit mass of a sample using the correction factor and the conversion factor. This configuration enables an accurate and inexpensive radioactivity inspection device and radioactivity inspection method having high detection efficiency to be provided.