Integration testing of safety-related systems: Lessons learnt from Dungeness B DPS replacement project

A major project is underway at Dungeness B nuclear power station in Kent, UK to replace the existing ´Data Processing System´ (DPS) with a modern equivalent system. The replacement project, being one of the major projects of its kind, is expected to provide many new lessons learnt in the areas of refurbishment/ replacement of large-scale C&I systems, particularly within the safety-related systems world of the nuclear industry. It is the purpose of this paper to report on a specific sub-activity within the project: on the ´integration testing´ of the higher integrity alarm and control applications within the replacement system. Over 300 test specifications are being produced currently for testing six separate control and alarm applications to be provided as part of the replacement system. The paper describes on the technical issues faced and the lessons learnt from this exercise, in particular from the efforts involved in the development of relevant test documentation. The paper reports on a work that is currently in progress and some of the observations made here may evolve as the work progresses to completion in coming months.