ML072700723
| ML072700723 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 09/12/2007 |
| From: | Bethay S Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| TAC MC9669 | |
| Download: ML072700723 (4) | |
Text
Im6ld- Entetg(Entergy Nuclear Operations, Inc.Pilgrim Nuclear Power Station 600 Rocky Hill Road Plymouth, MA 02360 Stephen J. Bethay Director, Nuclear Assessment September 12, 2007 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001
SUBJECT:
Entergy Nuclear Operations, Inc.Pilgrim Nuclear Power Station Docket No. 50-293 License No. DPR-35 License Renewal Application Commitment 47 Response
REFERENCES:
LETTER NUMBER:
Dear Sir or Madam:
- 1. Entergy Letter, Ucense Renewal Application, dated January 25, 2006 (TAC MC9669)2. Entergy Letter, Proposed Change to the Applicability of Pilgrim's Pressure-Temperature Curves, dated January 15, 2007 3. Entergy Letter, License Renewal Application Amendment 16, dated May 1, 2007 4. Entergy Letter, License Renewal Application Commitment 47 Response, dated August 23,2007 2.07.078 In Reference 1, Entergy Nuclear Operations, Inc. applied for renewal of the Pilgrim Nuclear Power Station operating license. In Reference 2, Entergy made a commitment to submit to the NRC an action plan to Improve benchmarking data to support approval of new P-T curves beyond cycle 18 for Pilgrim. This commitment was reaffirmed in Reference 3 as part of License Renewal Application Amendment
- 16. This letter supersedes Reference
- 4. Attachment A provides the action plan to address this commitment.
This letter contains no new commitments.
Please contact me at (508) 830-7800, if you have questions regarding this subject.I declare under the penalty of perjury that the foregoing is true and correct. Executed on September 12, 2007.Sincerely, Ste n J ethay Ste r J/leDir ctor, uclear Safe Assessment ERS/dl Attachment A: Action Plan to Improve Benchmarking Data (2 pages)/11 L6 Entergy Nuclear Operations, Inc.Pilgrim Nuclear Power Station Letter Number: 2.07.078 Page 2 cc: with Attachments Mr. Perry Buckberg Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Alicia Williamson Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 Susan L. Uttal, Esq.Office of the General Counsel U.S. Nuclear Regulatory Commission Mail Stop 0-15 D21 Washington, DC 20555-0001 Sheila Slocum Hollis, Esq.Duane Morris LLP 1667 K Street N.W., Suite 700 Washington, DC 20006 cc: without Attachments Mr. James S. Kim, Project Manager Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission One White Flint North O-8C2 11555 Rockville Pike Rockville, MD 20852 Mr. Jack Strosnider, Director Office of Nuclear Material and Safeguards U.S. Nuclear Regulatory Commission Washington, DC 20555-00001 Mr. Samuel J. Collins, Administrator Region I U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 NRC Resident Inspector Pilgrim Nuclear Power Station Mr. Joseph Rogers Commonwealth of Massachusetts Assistant Attorney General Division Chief, Utilities Division 1 Ashburton Place Boston, MA 02108 Mr. Matthew Brock, Esq.Commonwealth of Massachusetts Assistant Attorney General Environmental Protection Division One Ashburton Place Boston, MA 02108 Diane Curran, Esq.Harmon, Curran, and Eisenberg, L.LP.1726 M Street N.W., Suite 600 Washington, DC 20036 Mr. Robert Walker, Director Massachusetts Department of Public Health Radiation Control Program Schraft Center, Suite 1 M2A 529 Main Street Charlestown, MA 02129 Mr. Ken McBride, Director Massachusetts Energy Management Agency 400 Worcester Road Framingham, MA 01702 Mr. James E. Dyer, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatoiy Commission Washington, DC 20555-00001 ATTACHMENT A to Letter 2.07.078 Action Plan to Improve Benchmarking Data By letter dated January 15, 2007, Entergy made a commitment to submit to the NRC an action plan to improve benchmarking data to support approval of new P-T curves for Pilgrim Station for operation beyond cycle 18. In addition, the draft Safety Evaluation Report for Pilgrim's license renewal application Issued in March 2007 contained Open Item (01) 4.2 related to neutron fluence calculations necessary to support new Pressure-Temperature (P-T) curves for Pilgrim Station beyond cycle 18. By letter dated May 1, 2007 Entergy submitted license renewal application amendment 16 which contained a response to address 01 4.2 that included commitment
- 47 to submit to the NRC an action plan to improve benchmarking data to support approval of new P-T curves for Pilgrim Station.The benchmarking validation of the RAMA fluence calculation is ongoing for the Pilgrim reactor vessel and internals.
Uncertainties between the calculated and measured results from the dosimetry are still being examined to determine a possible cause for the discrepancy.
The following is the current plan that identifies all actions Entergy is pursuing to resolve the issue.Some of the actions have been completed.
- 1. Perform a sensitivity study to validate accuracy of the Input data lor the fluence model.This effort is two-fold:
Based on the fact that most of the core power history Is from dosimetry that was removed from the Pilgrim vessel during refueling outage (RFO) 4, Entergy is performing a detailed review of the power history developed to determine if adjustments are warranted.
In addition, our vendor is reviewing the RAMA fluence model to assure that input assumptions are not compounding the calculated to measured (C/M) bias. This effort is being undertaken to refine the original model, however, it is recognized that it will not lead to resolution of the Issue.2. The copper flux wires from the RFO 4 capsule pull were recently retested and results were similar to the original measurements.
Entergy has also Independently reviewed and validated the dosimetry counting methods used by the contracted vendor. They are considered to be accurate and correct. This effort was undertaken to verify that the original results were valid.3. Determine whether it would be useful to analyze jet pump swing gate samples that were removed from the Pilgrim vessel during RFO 16 In 2007 to obtain fluence Information for the required benchmark to resolve the issue.4. Review data from a similar EPRI sponsored BWR-3 to determine if it can be used to document an acceptable Regulatory Guide 1.190 C/M bias for a BWR-3 using the RAMA code. This could ultimately lead to resolution of the issue.5. Confirm with precision, the as-built dimensions for the location of the remaining dosimetry capsules In the Pilgrim reactor vessel. If the C/M bias Is not adequately resolved by the preceding actions, then evaluate the removal of dosimetry from a surveillance capsule In the Pilgrim vessel during RFO 17 scheduled for the spring of 2009. This dosimetry would then be analyzed to obtain an accurate fluence history for use in developing new P-T curves. This could ultimately lead to resolution of the issue.6. Consider contracting an independent vendor to model the vessel and perform a fluence calculation as a verification of the current results. Use of the data from action 3, 4 or 5 above would be required as input. This could ultimately lead to resolution of the issue.I of 2 I ' * -, ATTACHMENT A to Letter 2.07.078 Action Plan to Improve Benchmarking Data (continued)
This action plan contains a number of potential success paths that were developed from a Kepner-Tregoe analysis conducted by Entergy. Although there are several actions identified, Entergy believes that one of the following two approaches in the action plan, pursued in parallel, will be successful.
As identified in Action 4, an EPRI sponsored BWR-3 iis currently being modeled using the RAMA code. It is anticipated that the fluence results lfrom the EPRI sponsored plant will provide the successful benchmark required by Regulatory Guide 1.190 for the BWR-3 design eliminating the need for a Pilgrim specific benchmark.
In case Action 4 is not successful, Entergy is working in parallel to that effort (Action 5) to obtain precise measurements of an existing capsule location in the Pilgrim reactor vessel to support removal of dosimetry in the spring 2009 refueling outage for use in developing a new fluence calculation benchmark.
Although Action 3 may also lead to resolution of the issue, Entergy currently believes that one of the two approaches outlined in Actions 4 and 5 will be successful in meeting the Regulatory Guide 1.190 benchmark requirements for the BWR-3 design.This letter meets the commitment made by Entergy in the two letters referenced above and will allow for successful resolution of the data benchmarking issue to support the development of new P-T curves for Pilgrim.2 of 2