NRC 2014-0005, NextEra Energy Point Beach, LLC, Update to Response to NRC 10 CFR 50.54(f) Request for Information Regarding Near-Term Task Force Recommendation 2.3. Flooding- Review of Available Physical Margin (APM) Assessments
| ML14031A246 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 01/31/2014 |
| From: | Mccartney E Point Beach |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NRC 2014-0005 | |
| Download: ML14031A246 (5) | |
Text
January 31, 2014 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Point Beach Nuclear Plant, Units 1 and 2 Docket 50-266 and 50-301 Renewed License Nos. DPR-24 and DPR-27 NEXT era~*
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POINT BEACH NRC 2014-0005 50.54(f)
NextEra Energy Point Beach. LLC. Update to Response to NRC 10 CFR 50.54(f) Request for Information Regarding Near-Term Task force Recommendation 2.3. Flooding-Review of Available Physical Margin (APM) Assessments
References:
- 1. U.S. Nuclear Regulatory Commission, Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3 and 9.3 of the Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident, dated March 12, 2012 (ML12073A348)
- 2. U.S. Nuclear Regulatory Commission letter to Nuclear Energy Institute, Endorsement of Nuclear Energy Institute (NEI) 12-07, "Guidelines for Performing Verification Walkdowns of Plant Flood Protection Features," dated May 31, 2012 (ML12144A142)
- 3.
NextEra Energy Point Beach, LLC, letter to U.S. Nuclear Regulatory Commission, Response to 10 CFR 50.54(f) Request for Information Regarding Near-Term Task Force Recommendation 2.3, Flooding, dated November 20,2012 (ML12326A713)
- 4. U.S. Nuclear Regulatory Commission, Request for Additional Information Associated With Near-Term Task Force Recommendation 2.3, Flooding Walkdowns, dated December 23, 2013 (ML13325A891)
On March 12, 2012, the NRC staff issued Reference 1 requesting information pursuant to title 10 of the Code of Federal Regulations 50.54(f). Enclosure 4 of that letter contains a specific Requested Information associated with Near-Term Task Force Recommendation 2.3 for Flooding. Per Reference 2, the NRC endorsed Nuclear Energy Institute (NEI) 12-07, "Guidelines for Performing Verification Walkdowns of Plant Flood Protection Features,"
dated May 31, 2012. By Reference 3, NextEra Energy Point Beach, LLC, submitted the final report in response to the request for information.
One of the requirements of NEI 12-07 is to identify the available physical margin (APM) associated with each applicable flood protection feature, determine if the margin provided is small, and evaluate any small margins that have potentially significant consequences through the corrective action process. The results of this effort were to be maintained NextEra Energy Point Beach, LLC, 6610 Nuclear Road, Two Rivers, WI 54241
Document Control Desk Page 2 on site for future NRC audits.
Following the NRC staff's initial review of the walkdown reports, regulatory site audits were conducted at a sampling of plants. Based on the walkdown report reviews and site audits, the staff identified additional information is necessary to allow them to complete its assessments.
Accordingly, by Reference 4 the NRC staff has issued a request for information (RAI). The RAI questions and the NextEra Energy Point Beach, LLC, responses are provided in the enclosure to this letter.
This letter contains no new regulatory commitments.
If you have any questions, please contact Mr. Michael Millen, Licensing Manager, at 920/755-7845.
I declare under penalty of perjury that the foregoing is true and correct. Executed on January 31, 2014.
Very truly yours, NextEra Energy Point Beach, LLC Eric McCartney Site Vice President Enclosure cc:
Administrator, Region Ill, USNRC Resident Inspector, Point Beach Nuclear Plant, USNRC Project Manager, Point Beach Nuclear Plant, USNRC NextEra Energy Point Beach, LLC, 6610 Nuclear Road, Two Rivers, WI 54241
ENCLOSURE NEXTERA ENERGY POINT BEACH, LLC POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 UPDATE TO RESPONSE TO NRC 10 CFR 50.54(f) REQUEST FOR INFORMATION REGARDING NEAR-TERM TASK FORCE RECOMMENDATION 2.3, FLOODING - REVIEW OF AVAILABLE PHYSICAL MARGIN (APM) ASSESSMENTS The NRC staff has identified that additional information is necessary for assessment of Near-Term Task Force Recommendation 2.3 responses and has issued the following requests for information (RAI).
Provide confirmation that the process for evaluating Available Physical Margin (APM) was reviewed.
NextEra Response NextEra Energy Point Beach, LLC, has completed a review of the process used to evaluate APMs.
Provide confirmation that the APM process is now or was always consistent with the guidance in NEt 12-07 and discussed in this RAt.
NextEra Response The original walkdown effort followed the guidance provided in NEI 12-07, including a definition for a small margin. However, it was noted that probable maximum precipitation (PMP) event site drainage feature flood heights were recorded as "Not Applicable" (N/A) instead of "Unknown" and the protection heights were not recorded. Condition Report (CR) 01930711 was initiated and actions are being taken to correct this data.
A new analysis based on the current licensing basis was recently performed that documents PMP flood elevations at potential ingress paths. This resulted in some previously unknown APM values to be defined. The new flood elevations and associated APMs have been recorded. Flood locations with no margin or small APM have been entered into the Corrective Action Program (CAP) for disposition (CR 01932789, CR 01935048).
If changes are necessary, provide a general description of any process changes to establish this consistency.
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NextEra Response As stated in response to RAI 2 above, a correction is being made to the walkdown records for the PMP event site drainage features.
As a result of the audits and subsequent interactions with industry during public meetings, NRC staff recognized that evaluation of APM for seals (e.g., flood doors, penetrations, flood gates, etc.) was challenging for some licensees. Generally, licensees were expected to use either Approach A or Approach B (described below) to determine the APM for seals:
a) If seal pressure ratings were known, the seal ratings were used to determine APM (similar to example 2 in Section 3.13 of NEt 12-07). A numerical value for APM was documented. No further action was performed if the APM value was greater than the pre-established small-margin threshold value. If the APM value was small, an assessment of "significant consequences" was performed and the guidance in NEt 12-07 Section 5. 8 was followed.
b) If the seal pressure rating was not known, the APM for seals in a flood barrier is assumed to be greater than the pre-established small-margin threshold value if the following conditions were met: (1) the APM for the barrier in which the seal is located is greater than the small-margin threshold value and there is evidence that the seals were designed/procured, installed, and controlled as flooding seals in accordance with the flooding licensing basis. Note that in order to determine that the seal has been controlled as a flooding seal, it was only necessary to determine that the seal configuration has been governed by the plant's design control process since installation. In this case, the APM for the seal could have been documented as "not small".
As part of the RAt response, state if either Approach A or Approach B was used as part of the initial wa/kdowns or as part of actions taken in response to this RAt. No additional actions are necessary if either Approach A orB was used.
If neither Approach A orB was used to determine the APM values for seals (either as part of the wa/kdowns or as part of actions taken in response to this RAt), then perform the following two actions:
Enter the condition into the CAP (note: it is acceptable to utilize a single CAP entry to capture this issue for multiple seals). CAP disposition of "undetermined" APM values for seals should consider the guidance provided in NEt 12-07, Section 5. 8. The CAP disposition should confirm all seals can perform their intended safety function against floods up to the current licensing basis flood height. Disposition may occur as part of the Integrated Assessment. If an Integrated Assessment is not performed, determine whether there are significant consequences associated with exceeding the capacity of the seals and take interim action(s}, if necessary, via the CAP processes. These actions do not need to be complete prior to the RAt response.
Report the APM as "undetermined" and provide the CAP reference in the RAt response.
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NextEra Response Neither Approach A or 8, as described above, was used to determine the APM values for seals.
Currently, no seals are credited for external flooding protection. However, CR 01935230 has been initiated to evaluate whether additional flood design features are required as a result of the new PMP analysis.
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