The approach to legacy systems within the non-nuclear power station sector

During 2007 the management of legacy protection systems (ie those developed and implemented prior to the IEC 61508 standard) came to the fore. As almost every UK power station pre-dates the IEC 61508 standard they have a large number of such legacy protection systems to manage - hence the industry sector has a strong interest in this topic. All 9 UK generators have come together to form a technical working group to develop an approach and guidelines for the management of these systems on non- nuclear power stations. One of the principle issues addressed has been whether there is a need to retrospectively apply the whole safety life cycle of IEC 61508 to all of the legacy protection systems within the power stations - the conclusion has been no, only to a representative sample. The presentation describes the consideration leading to this conclusion and then go through the requirements of the approach and guidelines developed for the non-nuclear power station sector.