DS397 Saf Use Mod RRs with NUSSC comments 18-06-2010

5. PRE-IMPLEMENTATION PHASE OF A MODIFICATION OR UTILIZATIONPROJECTGENERAL5.1. Sections 5, 6 and 7 give detail guidance for the various phases in a typicalmodification or utilization project. The guidance should be followed for a project with majorsafety implications. For projects with lesser safety implications the guidance should be usedwith a graded approach as a basis for development of less restrictive requirements. Figure 1 isa flow chart for a project with major safety implications and shows the relationship betweenthe operating organization and the regulatory body during the execution of the project. Otherorganizations could be involved in the utilization or modification project, e.g. a designorganization or sub-contractors. For the design of a modification the operating organizationshould consult the designer to where possible. However, the overall responsibility remains atthe operating organization. The following paragraphs provide a detailed discussion of eachaspect of Figure 1.5.2. The extent of the involvement of the reactor safety committee and the regulatory bodydepends on the safety categorization of the utilization or modification and guidance for thesesteps are provided in Section 3.5.3. Projects with minor effect on safety should follow the same steps, but with a gradedapproach, especially regarding the extent and detail of the safety analysis, the documentationto be prepared and the review and approval route to be applied.5.4. Each stage of the project should be clearly defined and should be understood by allpersons involved. In particular, the transition points between stages should be formallyacknowledged5.5. At an early stage of the project the necessity to develop a mock-up should beconsidered to facilitate the development of procedures for the implementation, operatingprocedures, operator training or to ensure the feasibility of the modification or utilizationproject.PROJECT INITIATION5.6. The need for a modification or experiment can arise from different groups of persons,such as the reactor management, the regulatory body, experimenters and equipment suppliers.Modifications can involve changes to equipment, reactor operating conditions or procedures.21