Classification of events with an off-site radiological impact at the Sellafield site between1950 and 2000, using the International Nuclear Event Scale

Abstract

The paper assesses unplanned operational events at the Sellafield nuclear installation,formerly Windscale and Calder Works, in Cumbria, England, over the period 1950–2000that had, or could have had, radiological implications for members of the generalpublic. A unified system of off-site impact rating has been developed using asite-specific application of the International Nuclear Event Scale (INES) that isapplied retrospectively to events since the start of operations at the site in 1950.Published and unpublished sources of information have been used to assemblewhat the authors believe to be a complete list of events over the period thatwould now be assessed as INES level 3 or above on the basis of off-site impact.The last such event occurred in 1984. The exercise also demonstrates that it ispossible to apply the current INES rating scheme to a wide variety of radiologicalevents.