A Boron-10 Analyzer Engineered for CANDU Power Station Applications

Abstract

During the first year of operation of CANDU power reactors, boron is added to the moderator to compensate for the excess reactivity available in the fresh fuel. To assess the nuclear performance of the reactor in this period, precise measurements of several parameters are required, one of which is the concentration of the B-10 isotope in the moderator. This paper describes a transportable analyzer which is capable of measuring the concentration of B-10 in CANDU reactor moderator samples in the range of 0 to 5 ppm B-10. The measurement is based on the B-10(n,α)Li-7 reaction, where the induced alpha particle activity of evaporated samples can be related to the B-10 concentration of the moderator.