Investigations on the Improvement of the Iodine Filtration Concept of Boiling Water Reactors

The measurements performed in the exhaust air streams of two FRG boiling water reactors (BWRs) during normal operation show that the radioecologically decisive elemental ¹³¹ I is largely released to the environment by the unfiltered reactor and turbine building exhausts (order of magnitude of throughput: 100 000 m³/h each). It is concluded that, with respect to the release of elemental ¹³¹I, a reasonable improvement of the iodine filtration concept implemented in the two BWRs is not possible.