ML14183A393
| ML14183A393 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 04/07/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML14183A392 | List: |
| References | |
| NUDOCS 9904130319 | |
| Download: ML14183A393 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATING TO AMENDMENT NO. 181 TO FACILITY LICENSE NO. DPR-23 CAROLINA POWER & LIGHT COMPANY H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT 2 DOCKET NO. 50-261
1.0 INTRODUCTION
By letter dated August 28, 1997, as supplemented by letters dated June 17, 1998, October 29, 1998, and February 11, 1999, Carolina Power and Light Company (the licensee) requested NRC approval for a revision to the H. B. Robinson Steam Electric Plant, Unit 2 (HBRSEP) Updated Final Safety Analysis Report (UFSAR) that changes the design basis for fuel cask handling operations. The scenario concerns movement of spent fuel shipping cask model IF-300 from the decontamination facility at the HBRSEP to the shipping railcar using a crane in a non-single-failure-proof configuration, i.e using a non-redundant cask lifting yoke, without the cask valve covers installed. The analysis also considered a second scenario of potential damage by lateral movement of the cask into plant equipment that results in damage to the valves. The proposed revision would add a discussion in the UFSAR for the handling of an IF-300 fuel cask with less than the full designed cask integrity as above.
Spent fuel in an IF-300 shipping cask is routinely shipped from HBRSEP to another nuclear plant in the licensee's system for storage. When used within the limitations listed in its Certificate of Compliance (CoC)(with valve covers installed), the IF-300 shipping cask is designed to withstand being dropped from 30 feet onto an unyielding surface. In concert with review criteria in Section 15.7.5 of the NRC's NUREG-0800, Standard Review Plan (SRP), the consequences of a cask drop accident were not analyzed for HBRSEP since the potential drop of a spent fuel cask is limited to less than an equivalent 30-foot drop onto a flat, essentially unyielding, horizontal surface. However, recently the licensee has identified that some portions of the cask lifts used in removing the spent fuel from the spent fuel pool are performed with the protective exterior valve covers removed using a non single-failure-proof configuration, i.e, while using a non-redundant cask lifting yoke. Although these portions of the cask movements do not represent a potential drop of more than 30 feet, the licensee realized that such drops with less than the full cask integrity (valve covers removed) are outside the analyzed cask design and constitute an unreviewed safety question.
The licensee has analyzed the consequences of a cask drop accident with the cask configured as used at HBRSEP. This analysis indicates that, even without full cask integrity, dropping an IF-300 cask (30-foot equivalent drop) loaded with the maximum fuel loading results in offsite doses that are well within the acceptance criteria in the SRP. The licensee concluded that the cask drop analysis bounds any consequences that would be incurred due to cask impact during lateral movement during any part of the cask handling operation.
9DO4 1 3D39 990407 ADPCK 05000261 FOR PDR
2.0 EVALUATION The staff's evaluation of the proposed change -to the HBRSEP licensing basis consisted of reviewing the assumptions and methods in the licensee's radiological consequence analysis to ensure they are conservative, bounding, and consistent with the HBRSEP design basis. As a sample check, the staff also performed calculations for the control room using the HABIT Code with the licensee's input assumptions. The HABIT calculations gave doses consistent with the licensee's results. The licensee's consequence analysis assumed the bounding condition that the IF-300 cask was loaded with pressurized-water reactor fuel assemblies with maximum burn-up (45,000 MWd/MTU). In concert with item 10 of the IF-300 cask CoC (Certificate number 9001 Rev. 31), a minimum decay time of 5 years was assumed. The fuel pin gap activity and chemical composition assumptions were consistent with the guidance in Regulatory Guide (RG) 1.25. In addition, the maximum reactor power level (with a radial peaking factor of 1.65) consistent with the RG 1.25 guidance was assumed for each assembly. The licensee's analysis used the bounding assumption that 100% of the fuel pin gap activity in the fully loaded cask was released to the environment with no filtration. The worst case, short-term, ground level atmospheric dispersion values for the Exclusion Area Boundary listed in the HBRSEP FSAR were also applied.
The staff concludes, based on this evaluation, that the licensee has demonstrated with reasonable assurance that the maximum radiological consequences of dropping an IF-300 cask at HBRSEP are radiation doses to members of the public that are a small fraction of the numerical criteria in 10 CFR Part 100 and are well within the acceptance criteria in the SRP. The staff also finds that the licensee's analysis is reasonable in its conclusion that the consequences of the cask drop accident bound those that might be incurred due to impact from lateral movement. Therefore, they are acceptable.
3.0 STATE CONSULTATION
In accordance with its stated policy, on February 17, 1999, the staff consulted with the South Carolina State official, Virgil Autry, South Carolina Department of Health, Bureau of Radiological Health and Environmental Control. The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
Pursuant to 10 CFR 51.21, 51.32 and 51.35, an environmental assessment and finding of no significant impact has been prepared and published in the Federal Register on April 7, 1999 (64 FR 17019). Accordingly, based upon the environmental assessment, the staff has determined that the issuance of the amendment will not have a significant effect on the quality of the human environment.
5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that (1) there is reasonable assurance that the health and safety of the public will not be endangered by
operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: Roger Pedersen Date:
April 7, 1999