Print View Posted on: 13 April 2015
On the 2nd December 2013 three radiation workers opened 4 metal drums filled with compacted radioactive wastes containing 241-Am. The purpose of opening the drums was sorting and compaction of waste. During this operation contamination occurred. The control measurements found the worker’s hands, cloths, and the waste compactor room contaminated. The workers were surveyed by whole body-counter. According to the measurements over the chest carried out on the 13th of December the activities of incorporated 241-Am were as follows: 0,95 kBq, 1,27 kBq and 3 kBq for the three workers, respectively. Further whole-body counting measurements and urine analysis were taken to get more accurate data and to confirm the first measurements. The results were concluded by three methods: 1, based on the gamma-spectrometry measurements carried out over the chest,2, based on the gamma-spectrometry measurements carried out on urine analysis,3, based on the summarized and geometrical average data of both above mentioned measurements.The below published data were selected in a conservative manner. According to the mentioned gamma spectrometry measurements performed on the 17th December over the chest the highest committed effective dose for the next one year term were 18, 34, 250 mSv, and the five year term were 37, 71, 520 mSv respectively. According to the Hungarian rules regarding the doses of employees “during the occupation it shall not exceed the effective dose of 100 mSv dose limit per 5 consecutive years. In any single calendar year the effective dose shall not exceed 50 mSv”. The person who received the highest dose rate during the event may receive 250 mSv/1 year and 520 mSv/5 years committed effective dose without decorporation treatment. In summary, based on the Hungarian rules, measurements and on dose rate estimations the exposure of each worker exceeds the statutory annual dose limit, but does not exceed it greater than ten times. For this reason the final rating of the event is INES 2.