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

3.27. Modifications and experiments having significance effect on safety should bereviewed by the reactor safety committee and send to the regulatory body for review andapproval following approved procedures.Changes with minor safety significance3.28. Many experiments and modifications fall into this category. Besides the smallmodifications to structures, systems and components, research reactors are, by their nature,often used for repetitive sample irradiations or for repetitive experiments with minormodifications. The criteria for repetitive experiments, isotope production or modificationshaving only minor changes from the original approved design, which might be approved bythe reactor manager without re-submission to the safety committee or to the regulatory body,should be defined. The guidance given in Sections 5, 6 and 7 should be applied using a gradedapproach.3.29. Clear criteria should be defined, which irradiation of large number of samples, (e.g.for isotope production or activation analyses) may be regarded as a repetitive experiment. Theirradiation facility and the irradiation position (maximum allowable flux) should be specified.The information and documentation, which should be prepared to support the irradiationrequest and the review and approval route should also be specified in the procedure. Thisprocedure should be submitted to the safety committee for review.3.30. Records of experiments and minor modifications approved by the reactor managershould be periodically reviewed by the safety committee to ensure that there are nodisagreements in the interpretation of the criteria for approval.Changes with no effect on safety3.31. Careful consideration should be given to a proposed change before classifying it as amodification or utilization with no effect on safety. Such consideration should be based on adescription of the change, together with an assessment of its implications, and these should besubmitted to the reactor manager for approval.3.32. Records of all such approvals should be kept, together with the related documentation.3.33. The safety committee should periodically review the approval records, in order toensure that no disagreement exists in the interpretation of the criteria for approval.14