Detection device for control rod failures

Purpose: To reliably detect the control rod failures by continuously and automatically measuring the tritium amount in primary coolants at the downstream of the condensate desalters. Constitution: Primary coolants are continuously sampled from a branched pipe disposed to the downstream of a condensate desalter. Since the sampled primary coolants have been removed with impurities and salts, no pre-treatment is required. A fluorescent reagent injection pipeway for tritium detection, a specimen and reagent mixing coil and a liquid scintillation detector are connected to the primary coolant sampling pipe. The thus constituted device can continuously and automatically measure the tritium amount in the primary coolants. Accordingly, if tritium formed through the reaction of boron and neutrons in the control rod abnormally be increased in the primary coolants due to the failures, it can be detected rapidly. (Kamimura, M.)