A REVIEW OF NPL ENVIRONMENTAL-RADIOACTIVITY MEASUREMENT INTERCOMPARISON EXERCISES - 1989-95

Since 1989 the National Physical Laboratory (NPL) has conducted a seri es of five intercomparison exercises directed initially at the environ mental radioactivity measurement community in the UK, but now open to overseas participants. The complexity of the intercomparison samples h as increased with time. In general the results have been encouraging, but some problems have been highlighted, such as cascade summing and t he sources of nuclear data. The intercomparisons are reviewed and the changes and improvements observed over time are discussed. The implica tions for quality assurance are also addressed. Copyright (C) 1996 Pub lished by Elsevier Science Ltd.