Telescopic Measuring Method for Specific Activities of Structural Components in Reactor Pressure Vessel

Abstract

A nondestructive and quantitative method has been developed for telescopically measuring specific activities of neutron-activated structural components and the inner wall of a reactor pressure vessel (RPV) without interference from other extremely strong radioactivity. The method has been named the “Telescopic Measuring Method”. Evaluations of the measuring method were carried out in the Japan Power Demonstration Reactor (JPDR). It has been confirmed that the telescopic measuring method has an accuracy of 10~15% in the activity measurement for a reactor core shroud and an inner wall of a RPV when compared with specific activities determined by a sampling method.

KEYWORDS:

• nondestructive measuring method
• gamma spectroscopy
• specific activity
• activated structural component
• reactor vessels
• radionuclide inventory
• accuracy