AN INTERCOMPARISON OF RN-222 MEASUREMENT SYSTEMS IN EUROPEAN LABORATORIES

Recent years have seen an increase in awareness of the health hazards posed by environmental Rn-222. This has led to a large increase in the number of studies pertaining to this nuclide, which in turn has led t o a requirement for standards and calibration facilities. A recent mee ting of European national standards laboratories (under the EUROMET sc heme) revealed that many laboratories had developed (or were developin g) measurement systems for Rn-222. It was decided that an intercompari son of these systems would serve to demonstrate the consistency of mea surements being made within EUROMET laboratories and increase confiden ce among participants. A subsequent survey conducted by the National P hysical Laboratory led to the establishment of an intercomparison invo lving thirteen laboratories (including NPL itself). NPL conducted the intercomparison exercise by generating and standardizing a set of Rn-2 22 samples, and dispatching a unique subset of samples to each partici pating laboratory. The laboratories measured their samples and reporte d the results to NPL. The results of the exercise are presented and di scussed.