ML14184A334
| ML14184A334 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 02/01/1983 |
| From: | Varga S Office of Nuclear Reactor Regulation |
| To: | Utley E CAROLINA POWER & LIGHT CO. |
| References | |
| REF-GTECI-A-49, REF-GTECI-RV, TASK-A-49, TASK-OR NUDOCS 8302170434 | |
| Download: ML14184A334 (4) | |
Text
DISTRIBUTUN Docket File NRC PDR Local PDR FEB ORB 1 File 1983 D. Eisenhut OELD Docket No. 50-261 E. L. Jordan G. Requa C. Parrish Mr. E. E. Utley, Executive Vice President NSIC Power Supply and Engineering & Construction ACR (Taylor Carolina Power and Light Company J. Hles P. 0. Box 1551 PTS Distribution Raleigh, North Carolina 27602 G. isig G. Vissing
Dear Mr. Utley:
At the December 9, 1982 meeting with the Commissioners, the. staff presented results of its Pressurized Thermal Shock (PTS) studies as described in SECY P2-465. The staff was subsequently directed to develop a Notice of Proposed Rulemaking that would establish an RTNDT screening criterion, require licensees to submit present and projected values of RTNDT, require early analysis and implementation of such flux reduction programs as are reasonably practicable to avoid reaching the screening criterion, and require plant-specific PTS safety analyses before plants are within three calendar years of reaching the screening criterion. The staff's proposed screening values are an RTNDT of 270*F for plates and axial welds, and 300OF for circumferential we ds. The Commission also noted and concurred that the staff should meet with licensees of plants for which near-term flux reductions of factors of two to five would ensure that the screening criterion would not be exceeded throughout service life, to determine the licensees' plans for such programs, and propose issuance of 10 CFR 50.54(f) letters to such licensees, if appropriate, following the meetings. Based on the information available to us at that time, we requested such a meeting with you.
On November 8 and 12, 1982, your personnel along with personnel from Westinghouse and EPRI met with the staff and on January 25, 1983, your personnel again met with the staff at our request to discuss the program for ensuring that the screening criterion for PTS for Robinson 2 would not be exceeded. Based on your presentations and our discussion, we understand that Carolina Power and Light Company has already initiated a program intended to achieve a significant flux reduction in the next few years.
The current cycle 9 fuel contains a low leakage core that reduces the peak fluence on the reactor vessel walls by a factor of 2. Your staff also indicated that studies are underway for a cycle 10 reload that would achieve further flux reductions and that studies are planned for future fuel cycles with a goal of achieving the maximum reasonable flux reduction. We under stand that in order to achieve greater flux reduction with cycle 10 and future fuel loadings that you will require higher thermal margin limits.
During the January 25 meeting, your staff agreed to submit the information presented in the several meetings covering the present status and program schedule for flux reduction at your-facility. We request that the submittal include the following information, Most of which was addressed in your presentations during the November 8 and 12, 1982 and January 25, 1983 meetings.
oFFICE J...............................
SURNAMEb....
8302170434 830201 PDR ADOCK 05000261 DATE NRC FORM 318 (10-0) NRCM 0240 OFFICIAL RECORD COPY USGPO: 1981-335-960
FEB 1 18 Mr. E. E. Utley
- 2
- 1. Provide your assessment of the fluence experienced to date by the welds and plates in your pressure vessel, the rate of increase expected assuming future fuel cycles to which you are already committed, and a detailed description of the bases for the above (including surveil lance capsule data and analysis methods, and generic methods or correlations used).
- 2. Using the above fluence information, provide your assessment of-the RTNDT presently existing in your pressure vessel welds and plates utilizing the methodology outlined in Appendix E to Enclosure A of SECY-82-465, and the expected future rates of increase, and the expected dates when the applicable proposed screening criterion will be exceeded.
- 3. Provide a description of the flux reduction measures that you have instituted and additional measures that you are considering for your plant. Indicate your estimated schedule for the studies in progress. Include for each option:
- a. Description of fuel management and/or fuel removal and/or fuel replacement with dummy elements including an indication of power level of outer assemblies in the axial and radial directions for future cycles;
- b. Quantitative assessment of resulting flux reduction to critical welds and plates;
- c. Parametric study showing future RTNDT values resulting from both the earliest practicable implementation of the option, and from the latest possible implementation of the plan that will still avoid exceeding the RTNDT screening criterion at the expiration of your operating license.
- d. Discussion of advantages and disadvantages of the options particu larly emphasizing power reductions caused by the option. With respect to power reduction, discuss the magnitude of the reduction and the particular limit (e.g., hot channel factor, DNBR, etc.)
causing the power reduction. Also analyze how much relief would be necessary (with respect to the particular limit) to allow full power operation, and assess whether such relief would be an improve ment to overall plant safety (considering LOCA, PTS, transients, etc.).
- 4. Discuss any alternatives you may be considering to flux reduction that will result in delaying or avoiding exceeding the RTNDT screening criterion.
These would include topics such as archival materials research, plans to sample and analyze as-built materials, etc.
OFFICE SURNAME DATE I........................
NRC FORM 318 (10-80) NRCM 0240 OFFICIAL RECORD COPY USGPO: 1981-335-960
We request that the above information be provided within 60 days of your receipt of this letter. We plan to meet with Yout :t.fff in March to discuss FAHaand FQ,imit revisions for cycle 10 reload and we may request a meeting with you to discuss your options and plans after we have reviewed the above requested information, atid as your studies progress.
OMB clearance is not required for this request since it is being transmitted to fewer than 10 addressees.
Sincerely, Orxiginal signed bYi A. A. Varga Steven A. Varga, Chief Operating Reactors Branch No. 1 Division of Licensing cc:
See next page ORB OR D/~6TD OFFICE F.
.D SURNAME I
DATE j *...
- 83.
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NRC FORM 318 (10-80) NRCM 0240 OFFICIAL R ECORD COPY USGPO:1981-335-960
Mr. E. E. Utley Carolina PoWer and Light Company cc: G. F. Trowbridge, Esquire Shaw, Pittman, Potts and Trowbridge 1800 M Street, N.W.
Washington, D. C. 20036 U. S. Nuclear Regulatory Commission Resident Inspector's Office H. B. Robinson Steam Electric Plant Route 5, Box 266-1A Hartsville, South Carolina 29550 James P. O'Reilly Regional Administrator - Region II U. S. Nuclear Regulatory Commission 101 Marietta.Street - Suite 3100 Atlanta, Georgia 30303