1CAN031003, Deviation from NEI Guideline - RCS Leakage Action Levels
| ML100830647 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 03/24/2010 |
| From: | David Bice Entergy Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 1CAN031003 | |
| Download: ML100830647 (5) | |
Text
1CAN031003 March 24, 2010 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
SUBJECT:
Deviation from NEI Guideline - RCS Leakage Action Levels Arkansas Nuclear One, Unit 1 Docket No. 50-313 License No. DPR-51
REFERENCES:
- 1.
NEI 03-08, Guideline for the Management of Materials Issues, April 2007 Addenda, Materials Initiative Guidance, Addendum E, Rev. 3
- 2.
Pressurized Water Reactor Owners Group, Standard RCS Leakage Action Levels and Response Guidelines for Pressurized Water Reactors, WCAP-16465-NP
Dear Sir or Madam:
In accordance with Nuclear Energy Institute (NEI) 03-08 (Reference 1), Entergy Operations, Inc. (Entergy) is informing the NRC of a needed deviation from the Pressurized Water Reactor Owners Group (PWROG) WCAP-16465-NP (Reference 1) relating to Reactor Coolant System (RCS) leakage for Arkansas Nuclear One, Unit 1 (ANO-1). Addendum E of NEI 03-08 states:
Utilities shall notify the NRC of any approved deviations from Mandatory and Needed guideline elements. This notification is for information; NRC approval or other actions are not expected. The notification shall summarize:
the guidance being deviated from, the justification for the deviation, and any actions undertaken in lieu of the guidance.
Entergy Operations, Inc.
1448 S.R. 333 Russellville, AR 72802 Tel 479-858-4710 David B. Bice Acting Manager, Licensing Arkansas Nuclear One
1CAN031003 Page 2 of 2 Note that the attached justification is an internal Entergy document and was not written in a manner requesting NRC approval. As stated above, this justification is for informational purposes only.
This letter does not include any new commitments.
If you have any questions or require additional information, please contact me.
Sincerely, DBB/rwc
Attachment:
Technical Justification and Compensatory Measures and Controls for Deviation cc:
Mr. Elmo E. Collins Regional Administrator U. S. Nuclear Regulatory Commission Region IV 612 E. Lamar Blvd., Suite 400 Arlington, TX 76011-4125 NRC Senior Resident Inspector Arkansas Nuclear One P. O. Box 310 London, AR 72847 U. S. Nuclear Regulatory Commission Attn: Mr. Kaly Kalyanam MS O-8 B1 One White Flint North 11555 Rockville Pike Rockville, MD 20852
Attachment to 1CAN031003 Technical Justification and Compensatory Measures and Controls for Deviation
Attachment to 1CAN031003 Page 1 of 2 Technical Justification and Compensatory Measures and Controls for Deviation Guidance Deviated From Arkansas Nuclear One, Unit 1 (ANO-1) has three High Pressure Injection (HPI) pumps, one of which is normally in service to provide Reactor Coolant System (RCS) Makeup and Reactor Coolant Pump (RCP) seal injection.
Elevated RCS leakage was determined to exist on December 29, 2008. Unidentified RCS leakage was 0.182 gallons per minute (gpm). This correlates to a 0.134 gpm rise above the 5-day average of 0.048 gpm. Total RCS leakage was elevated to 0.203 gpm, 0.135 gpm higher than the previous days total leakage. This elevated leakage is well within the ANO-1 Technical Specification limits.
Elevated leakage is only present when the green train HPI system is in service and results in leakage from the Letdown System to the Borated Water Storage Tank (BWST) and varies slightly with Makeup Tank Pressure. Changes have been made to the RCS leak rate procedure which acknowledges this issue. In lieu of entering the inflated green train unidentified leak rate (ULR) into the RCS trend spreadsheet, the operator is directed to use the previous 7-day average instead. This ensures the inflated ULR daily values will not result in non-conservatively raising the average ULR value in an upward direction, potentially masking a small leak when the system is realigned to red train.
The normal ANO-1 RCS leak detection procedure provides guidance for most instances of increased leakage. The actions listed with associated trigger points in the Operational Decision-Making Issue (ODMI) process are actions that are not addressed in the normal procedures.
During a recent assessment of ANO / Entergy Primary Systems Materials program, it was recognized that ANO-1 is not in full compliance with Reference 1. Specifically, the foundation for the procedural trigger points and actions, superseded by the ODMI, was based upon standardized RCS leakage guidelines, established by the PWROG (Reference 2). It was determined that non-compliance with Reference 2, results in non-compliance with Reference 1.
This deviation exists only when the green train HPI system is in service.
Justification for Deviation RCS leakage is quantified on a daily basis through the performance of the appropriate procedure. It has been noted that the RCS leakage is elevated while a green train HPI pump was in service. Green train stop check valve BW-2 and BWST outlet valve CV-1408 were found to be leaking by, resulting in leakage from the Makeup Tank to the BWST at the rate of
~0.15 gpm. The guidance and direction given to Operations in this condition introduces the deviation from the PWROG guidelines. The specific guidance provided considered Technical Specification limits s and actions levels which currently exist in Operations procedures.
Additional considerations included the radiological impact upon the BWST and potential offsite dose consequences.
Attachment to 1CAN031003 Page 2 of 2 Absolute quantification of leakage can only be achieved by rendering one train of HPI inoperable and making an entry into a 72-hour Limiting Condition of Operations and stationing a dedicated operator.
Actions Undertaken in Lieu of Guidance Document No direct compensatory measures are required to be taken as a result of this condition. RCS leak rate determination will continue to be performed daily and the values compared to trigger points. In the unlikely event that a failed fuel condition develops while a green train HPI pump is operating, monitoring of the BWST and associated outlet piping will be initiated in accordance with station guidance.
The system alignment allowing this condition is being minimized to allow only mandatory surveillance testing and maintenance activities until the condition can be corrected.
This guidance will be in place until the Spring 2010 refueling outage for ANO-1. At that time, repairs will be implemented on CV-1408 and BW-2.
References
- 1.
NEI 03-08, Guideline for the Management of Materials Issues, April 2007 Addenda, Materials Initiative Guidance, Addendum E, Rev. 3
- 2.
Pressurized Water Reactor Owners Group, Standard RCS Leakage Action Levels and Response Guidelines for Pressurized Water Reactors, WCAP-16465-NP