AMS measurements of 14C, 36Cl, and 239/240Pu samples taken in a ‘small facility’

The release of nuclear facilities from regulatory control is commonly addressed by demonstrating that contaminations are below ‘clearance values’. AMS is commonly too laborious for a large number of samples, especially if nuclide vectors have been established, but it might be of interest for the release of a so-called ‘small facility’. For this case study, a radiochemistry laboratory in Cologne, Germany was chosen. It was known that 14C, 36Cl as well as 240Pu had been handled openly in this lab. There were no apparent contaminations, i.e., no alpha/beta contaminations that could be detected using a hand-held radiation monitor. Elevated values of 14C were measured in three, increased values of 36Cl in all and 239Pu in only one of the examined samples. All measured activities are well below the release values, but it can be proven that the elements 14C, 36Cl, 239Pu were handled openly in the ‘small facility’.