Regulatory challenges of decommissioning safety assessments: lessons learned frominternational experience (DeSa project)

摘要

As the number of facilities undergoing decommissioning world-wide increases, thechallenges associated with the conduct and regulation of decommissioning become more apparent. This isparticularly the case in smaller countries, where there may be no internal experience to draw upon other than theexperience gained during operation. In recognition of the need to share experience and to improve the guidanceavailable to organizations and countries undertaking decommissioning projects, the IAEA is coordinating theDecommissioning Safety Assessment (DeSa) project. One of the principal themes within the work of the DeSaproject has been the development of practical guidance on the regulatory review of safety assessments, based onthe experience of Member States. During this work, representatives of regulatory agencies in participatingcountries have exchanged information on their experiences and lessons learned from the regulation ofdecommissioning projects. This exchange of experience has demonstrated that the successful regulation of adecommissioning project requires a different approach than simply applying the same processes that were usedto regulate the construction and operation of the facility. The regulatory approval process must take into accounttime at risk arguments and the existence and effectiveness of procedural controls, rather than relying on designfeatures. The risk profile for a decommissioning facility often involves short duration increases in risk in order tomove the facility into a lower risk configuration in the long term. The management of safety changes from arelatively steady condition during operation to a fully dynamic situation where change is the only constant.Therefore safety assessment, for both the operator and the regulator, becomes increasingly focused onorganizational processes rather than purely technical matters. These organizational processes include proceduralcontrols for the conduct of work as well as internal review and authorization systems to reduce the need forregulatory approval of short-lived configuration changes.