Monte Carlo modelling and real-time dosemeter measurements of dose rate distribution at a 60Co industrial irradiation plant

The dose rate distribution in a MDS Nordion JS7500 60Co industrial irradiation plant has been calculated using the egspp Monte Carlo code. This code is a development of the established EGSnrc code developed and distributed by National Research Council of Canada.The coding method is described and absolute dose rates given for each of the dwell positions in the path through the irradiator. These calculated dose rates have been compared with measurements made using a radiation resistant electronic dosimetry system. In addition, the integral dose derived from calculated and measured dose rates has been compared to the value obtained using chemical dosimeters.