Current problems in the assessment of the effectiveness of radioiodine release control

In the opening session of the 19th DOE/NRC Nuclear Air Cleaning Conference R.M. Bernero demonstrated the environmental significance of iodine releases from normal operations and supported it with results of numerous field investigations. The behavior of airborne radioiodine in BWR and PWR operations, as presented in this paper, was similar in many aspects to its behavior observed in operational areas and gaseous effluent of PHW reactors. While the identity of airborne non-I2, non-CH3I species has not yet been conclusively identified, there cannot be any doubt on their presence in areas and effluent of nuclear facilities. Since only iodomethane and elemental iodine tests are currently available for the performance testing of radioiodine absorbers, the test results may not properly represent the adequacy of radioiodine effluent control under certain operational or release conditions. Data from field measurements of radioiodine at PHWRs are compared with data from similar measurements taken at US power plants, in order to relate the behavior pattern of airborne radioiodine and to assess the need for its effluent control under both typical operations and accidental conditions in nuclear power plants