Estimation of radiation dose rate in new polypropylene strainer in primary heat transport system

Heavy water is used in Primary Heat Transport system at Dhruva research reactor. It contains suspended and ionic impurities, therefore it is required to purify heavy water for removal of impurities and to maintain grade of heavy water. For enhancing performance of purification system testing of new polypropylene filters is planned for removal of suspended impurities at flow rate of 400 lit/min. Physical properties of polypropylene changes after exposure to radiation after radiation dose of 1.0E+05 Gy it becomes brittle. Calculations of beta and gamma radiation dose rate are based on the activity of radionuclides present in heavy water used as main coolant system. Assessment of service life of new filters is carried out by calculating the radiation dose rate to polypropylene filters during in service and radiation dose rate of existing removed stainless steel strainer. (author)