Improvement of the Iodine Monitoring System at McMaster Nuclear Reactor

Abstract

Iodine-125 is one of the radioactive isotopes produced at the McMaster Nuclear Reactor (MNR). It is used especially for thyroid treatment and prostate cancer therapy. However, chronic doses of small quantities of I-125 for workers can harm the body especially the thyroid organ. I-125 gamma photons are very difficult to detect since they have a very low energy. A suitable detection system is required to enable the monitoring of very small concentrations of I-125 in the air. The purpose of this paper is to describe the production and monitoring of I-125 at MNR and to demonstrate an improved monitoring system for the concentration of I-125 released to the air. A computer program, with appropriate peripherals run within the LabVIEW* environment, has been employed to improve the monitoring and advising system, finding the count rate, and analyzing the data. All these are to give the nuclear reactor operators a computerized, simple, safe and flexible monitoring facility.