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History of SQUG
SQUG Formed NRC Endorses Use of
Experience Data In early 1987, the NRC issued Generic Letter (GL) 87-02 [Reference 1] to owners of operating nuclear plants in the United States that were licensed prior to development of modern seismic qualification standards. The recipients of GL 87-02 are referred to as A-46 plants. Essentially, all owners of A-46 plants were members of SQUG. GL 87-02 required owners to take action to verify the seismic adequacy of important equipment in their plants. A number of International utilities with older nuclear power plant also joined SQUG to address the same type of concern that the NRC had for older U.S. nuclear power plants. GIP Developed A significant finding of the research upon which the GIP is based is that the conventional electrical and mechanical equipment included in the scope of the GIP will withstand earthquakes that are significantly higher than the design basis earthquakes for eastern U.S. nuclear plants, provided the criteria outlined in the GIP are met. The guidelines in the GIP provide a systematic, controlled, and well-documented method of applying the lessons learned from review of equipment performance during earthquakes and tests. The GIP screens out those types of conventional equipment that have been shown to be insensitive to earthquake motions expected in eastern U.S. plants and focuses on actual equipment and installation vulnerabilities identified in strong motion earthquakes and prior qualification tests. This process has been demonstrated to be cost-effective in identifying risk-significant seismic issues without reducing seismic design margins for the plants. In addition to addressing the issues associated with USI A-46, the GIP also explicitly addresses the issues associated with methods of analysis for aboveground, flexible, vertical storage tanks identified in USI A-40, “Seismic Design Criteria” [Reference 2]. Similarly, the GIP explicitly addresses the seismic adequacy of equipment and structures that are in close proximity to important-to-safety equipment identified in USI A-17, “Systems Interactions in Nuclear Power Plants” [Reference 3]. SQUG issued several revision of the GIP from 1988 to 1992 with new and improved criteria and guidelines. The version issued on February 14, 1992, (GIP-2) included criteria and guidelines that resulted from extensive discussions and subsequent agreements reached with the NRC staff and the Senior Seismic Review and Advisory Panel (SSRAP). As discussed below, the NRC identified this revision of the GIP as the definitive version for implementing the USI A-46 program. SSRAP Supported Use of
Experience Data Trial Plant Reviews NRC Accepts Use of GIP-2 GIP-2A Issued SQUG Training Program
More details on these courses and access to the training material associated for some of them are posted on SQUG Training section of this web site for use by members. SEQUAL Formed GIP-3 Issued GIP-3A Issued By using GIP-3A, SQUG members have a better chance of avoiding inadvertent errors that would result from omitting or misinterpreting the NRC’s clarifications, interpretations, positions, exceptions, and issues that are included in the two SSERs and their letter to SQUG on the NARE Guidelines. SQUG recommended that members use GIP-3A as a working level document for their day-to-day seismic qualification of equipment in their plants, including New and Replacement Equipment (NARE) [Reference 20]. In developing GIP-3A, SQUG endeavored to incorporate the NRC clarifications, interpretations, positions, exceptions, and issues in a manner that it believes would be acceptable to the Staff without adding new, substantive criteria or guidance into the document. Therefore, even though GIP-3A has not been formally reviewed and approved by the NRC Staff, SQUG considers this document to be an additional statement of the accepted criteria and guidance, not a change to the criteria and guidance provided in the baseline documents that had been reviewed and approved by the NRC Staff. NARE Application For SQUG members to use the GIP method for seismic qualification of new and replacement equipment (NARE), it is advisable, if not necessary, to modify the plant licensing basis to allow use of the GIP as an alternative (see NRC letter to SQUG dated 6/19/98, Reference 14). To assist members in changing the plant licensing basis, SQUG prepared Revision 0 of a 50.59 Template (Reference 17). This template is based upon the NEI guidance available at the time for preparing 50.59 safety evaluations (NEI 96-07, Revision 0). Specifically, Section 3 of the template offers suggested language to answer the seven questions from NEI 96-07, Revision 0. The template also reflected the guidance provided by the NRC in their letter to SQUG (Reference 14) in which the NRC agreed that the 50.59 process is an acceptable method to adopt the GIP, based on their expectation that a detailed comparison of a plant’s licensing basis with comparable elements of the GIP will be performed to support the 50.59 evaluation. Appendix A of the template compares typical elements in the licensing basis for A-46 plants to comparable elements in GIP-3. This comparison is intended to show that there is no reduction in the plant safety margin. Appendix B of the template provides suggested language which may be included in the plant’s USAR for adopting the GIP method as an alternative seismic qualification method. Subsequently, SQUG updated the 50.59 Template to Revision 1 (Reference 19) to make it consistent with the amendments made by the NRC to 10 CFR 50.59 that became effective March 13, 2001, and the NEI guidance for applying this new 50.59 process, as contained in NEI 96-07, Revision 1. The 50.59 Template was also revised to reference GIP-3A and make other improvements. SQUG’s Future References 1. Generic Letter 87-02, “Verification of Seismic Adequacy of Mechanical and Electrical Equipment in Operating Reactors, Unresolved Safety Issue (USI) A-46,” U.S. Nuclear Regulatory Commission, Washington, DC, February 19, 1987. 2. USI A-40 “Seismic Design Criteria Short-Term Program”, USNRC, Washington, D.C. 3. USI A-17 “Systems Interactions in Nuclear Power Plants” USNRC, Washington, D.C. 4. Sandia National Laboratories Report SAND92-0140, UC-523, June 1992, containing two reports originally published by the Senior Seismic Review and Advisory Panel (SSRAP) on (1) Use of Seismic Experience and Test Data to Show Ruggedness of Equipment in Nuclear Power Plants, and (2) Review Procedure to Assess Seismic Ruggedness of Cantilever Bracket Cable Tray Supports. 5. Part I of Sandia Report SAND92-0140, UC-523 [Reference 0 above]: SSRAP Report, “Use of Seismic Experience and Test Data to Show Ruggedness of Equipment in Nuclear Power Plants,” originally published by SSRAP on 2/28/91. 6. Part II of Sandia Report SAND92-0140, UC-523 [Reference 0 above]: SSRAP Report, “Review Procedure to Assess Seismic Ruggedness of Cantilever Bracket Cable Tray Supports,” originally published by SSRAP on 3/1/91. 7. Generic Letter 87-02, Supplement No. 1, Transmitting Supplemental Safety Evaluation Report No. 2 (SSER No. 2) on SQUG Generic Implementation Procedure, Revision 2, as Corrected on February 14, 1992 (GIP-2), U.S. Nuclear Regulatory Commission, Washington, DC, May 22, 1992. 8. SQUG (N. Smith) letter to NRC (J. Partlow), dated 8/21/92, describing SQUG’s understanding of SSER No. 2. 9. NRC (J. Parlow) letter to SQUG (N. Smith), dated 10/2/92, with enclosure containing NRC Staff comments on SQUG’s 8/21/92 letter. 10. SQUG (N. Smith) letter to NRC (J. Partlow), dated 3/26/93, forwarding Revision 2A of the Generic Implementation Procedure (GIP-2A) along with a description of how SQUG addressed the NRC comments in SSER No. 2 (Enclosure 2) and an explanation of the clarifications made in GIP-2A (Enclosure 3). 11. NRC (W. Butler) letter to SQUG (N. Smith), dated 5/24/93, NRC Response to SQUG Letter Dated March 26, 1993, on GIP-2A. 12. SQUG (N. Smith) memorandum to SQUG members, dated 8/4/93, Use of GIP Revision 2A. 13. NRC (J. Stolz) Letter to SQUG (N. Smith), dated December 4, 1997, forwarding the NRC’s “Supplemental Safety Evaluation Report No. 3 (SSER No. 3) on the Review of Revision 3 to the Generic Implementation Procedure for Seismic Verification of Nuclear Power Plant Equipment, Updated May 16,1997, (GIP-3).” 14. NRC (B. Sheron) letter to SQUG (N. Smith), dated 6/19/1998, NRC Position of Use of 10 CFR 50.59 Process to Change Plant Licensing Basis to Adopt GIP Methodology. 15. SQUG (N. Smith) letter to NRC (R. Capra) dated 7/15/1998, forwarding the Report on the Use of the GIP for New and Replacement Equipment and Parts (NARE). 16. NRC (E. Adensam) letter to SQUG (N. Smith) dated 6/23/99, forwarding the NRC’s Review of SQUG’s Report on the Use of the Generic Implementation Procedure for New and Replacement Equipment and Parts (NARE). 17. SQUG (J. Richards and R. Kassawara) memorandum to SQUG members, dated 7/24/2000, forwarding the 50.59 Template, Revision 0, “Template for 50.59 Safety Evaluations to Adopt the GIP as a Licensing Basis Method. 18. SQUG (J. Richards and R. Kassawara) memorandum to SQUG members, dated 7/25/00, forwarding the NARE Guidelines, Revision 4, “Implementation Guidelines for Seismic Qualification of New and Replacement Equipment/Parts (NARE) Using the Generic Implementation Procedure (GIP).” 19. SQUG (J. Richards and R. Kassawara) memorandum to SQUG members, dated 10/23/2002, forwarding the updated NARE Guidelines, Revision 5 and the updated 50.59 Template, Revision 1. 20. SQUG (J. Richards) memorandum to SQUG members dated 6/14/2005, “Use of GIP Revision 3A,” recommending that SQUG members use GIP-3A for future work, including NARE applications. Last Updated: 11/19/2018 |
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