Supply air filters after the nuclear reactor accident at Chernobyl

In the case of increased activity concentration in the air supply air filters are the facility compounds where enhanced activity is collected. Therefore, it was understandable that the people put questions about the doses caused by supply air filters after the nuclear reactor accident at Chernobyl. When comparing the local dose rate at a distance of 1 m in front of filters with the outdoor local dose rate due to dry deposited radionuclides, nearly the same local dose rate results assuming an air flow rate of approx. 60 m3/h. Supposing a 10 hours stay at a distance of 1 m in front of filters and an air flow rate of approx. 5000 m3/h the same dose is obtained after a 10 days delay as the dose due to outdoor inhalation. At Aachen, the local dose rate near to filters increased up to approx. 10 μSv/h. After a suitable time delay of one month filters could be rejected like normal waste. A review is given on individual measured values