Contra-expertise on the determination of radioactivity of waste water and ventilation air of NRG : Period 2011
Contra-expertise op bepalingen van radioactiviteit van afwalwater en ventiliatielucht van NRG : Periode 2011
03 May 2013, PDF |
25 pages |
Kwakman PJM, Overwater RMW
RIVM Report 610330135
Within the framework of a monitoring programme, RIVM measures the release of radioactivity into the waste water and atmosphere of NRG. Measurements are carried out eight times per year. This form of counter-expertise is aimed at verifying and supporting the reliability of the analyses carried out by NRG. In 2011, the two different sets of measurements are generally in agreement for gammaspectrometry and gross alpha results in waste water. The few discrepancies that were observed concern the presence of gross beta emitters in waste water. This is partly explained by the presence of short-lived betaemitters in waste water of NRG, and partly because of differences in the analytical methods applied by NRG and RIVM. The agreement in 3H in waste water needs some improvement.
The results obtained by RIVM and NRG in ventilation air samples are in good agreement. Gross alpha and gross beta results are all close to the detection limit. There is no significant difference between these results and the results obtained in outside air in Bilthoven. In the only case where the gammaspectrometry result can be compared the agreement for 131I in the first sample is good.
The RIVM analyzed eight waste water samples and eight samples of ventilation air taken by NRG at various time points dispersed throughout 2011. The analyses were carried out on behalf of the Department of Nuclear Safety, Security and Safeguards of the Dutch Ministry of Infrastructure and Environment.