ML14037A207
| ML14037A207 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 01/31/2014 |
| From: | Dent J Entergy Nuclear Operations |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML14037A207 (13) | |
Text
a Entergy
' Entergy Nuclear Operations, Inc.
Pilgrim Nuclear Power Station 600 Rocky Hill Road Plymouth, MA 02360 John A. Dent, Jr.
Site Vice President January 31, 2014 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852
SUBJECT:
Update to Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding the Flooding Aspects of Recommendation 2.3 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident - Review of Available Physical Margin (APM) Assessments Pilgrim Nuclear Power Station Docket No. 50-293 License No. DPR-35
REFERENCES:
- 1. NRC Letter, "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-ichi Accident", dated March 12, 2012 (ADAMS Accession No. ML12053A348)
- 2. NRC 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, (ADAMS Accession No. ML12144A142)
- 3. Entergy Letter to NRC, "Flooding Walkdown Report - Entergy's Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding the Flooding Aspects of Recommendation 2.3 of the Near-Term Task Force Review of Insights from Fukushima Dai-ichi Accident, dated November 27, 2012 (PNPS Letter 2.12.076)
- 4. Entergy Letter to NRC, "Supplemental Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding the Flooding Aspects of Recommendation 2.3 of the Near-Term Task Force Review of Insights from Fukushima Dai-ichi Accident, dated November 26, 2013 (PNPS Letter 2.13.086)
- 5. NRC Letter, "Request for Additional Information Associated with Near-Term Task Force Recommendations 2.3, Flooding Walkdowns", dated December 23, 2013 (PNPS Letter 1.13.072)
LETTER NUMBER 2.14.004
Dear Sir or Madam:
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 specific Requested Information associated with Near-Term Task Force Recommendation 2.3 for
PNPS Letter 2.14.004 Page 2 of 4 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, Pilgrim Nuclear Power Station (PNPS) submitted the Flooding Walkdown Report in response to the request for information. By Reference 4, PNPS submitted a supplemental response to the Flooding Walkdown Report where restricted areas prevented walkdown of certain flood protection features.
One of the requirements of NEI 12-07 is to identify the available physical margin (APM) associated with each flood protection feature, determine ifthe 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 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 necessary to allow them to complete its assessments.
Accordingly, by Reference 5 the NRC staff has issued a request for addition information (RAI).
The RAI questions and the PNPS responses are provided below.
RAI Number 1: Confirmation that the process for evaluating APM was reviewed.
Response 1: Entergy has completed a review of the process used at PNPS to evaluate APMs.
RAI Number 2: Confirmation that the APM process is now or was always consistent with the guidance in NEI 12-07 and discussed in this RAI.
Response 2: The original walkdown effort followed the guidance provided in NEI 12-07, including a definition for a small margin. Additional actions have been taken to make the process consistent with the information provided in this RAI.
RAI Number 3. If changes are necessary, a general description of any process changes to establish this consistency.
Response 3: As stated above, the original walkdown effort followed the guidance provided in NEI 12-07, including a definition for a small margin. However, a specific APM had not been assigned to the seals associated with flood protection features. These items have now been addressed in accordance with the guidance provided in this RAI and entered into the corrective action process, as appropriate, for further evaluation.
RAI Number 4: 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 NEI 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 NEI 12-07 Section 5.8 was followed.
PNPS Letter 2.14.004 Page 3 of 4 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 RAI response, state if either Approach A or Approach B was used as part of the initial walkdowns or as part of actions taken in response to this RAI. No additional actions are necessary if either Approach A or B was used.
If neither Approach A or B was used to determine the APM values for seals (either as part of the walkdowns or as part of actions taken in response to this RAI), 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 NEI 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 RAI response.
Response 4: Neither Approach A or B, as described above, were used to determine the APM values for seals. All seals were inspected as part of the original walkdowns for signs of degradation, and corrective actions were taken, if required. As part of the actions taken to address this RAI, the seals have been assigned an APM value of "undetermined" and have been entered into the CAP process for further evaluation of their available physical margin.
Implementation of interim actions will be pursued, if necessary.
Refer to Attachment "NTTF Recommendation 2.3: Flooding Walkdowns Available Physical Margin (APM) Summary Table" for flooding walkdown record forms.
This letter contains no new regulatory commitments.
Should you have any questions concerning the content of this letter, please contact Mr. Joseph R. Lynch, Manager, Regulatory Assurance at (508) 830-8403.
PNPS Letter 2.14.004 Page 4 of 4 I declare under penalty of perjury that the foregoing is true and correct; executed on January 31, 2014.
Sincerely, oh .Dent Jr.
Site Vice President JAD/rmb
Attachment:
"NTTF Recommendation 2.3: Flooding Walkdowns Available Physical Margin (APM) Summary Table" cc: Mr. William M. Dean Regional Administrator, Region 1 U.S. Nuclear Regulatory Commission 2100 Renaissance Boulevard, Suite 100 King of Prussia, PA 19406-1415 U. S. Nuclear Regulatory Commission Director, Office of Nuclear Reactor Regulation One White Flint North 11555 Rockville Pike Rockville, MD 20852 Ms. Nadiyah Morgan, Project Manager Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop O-8C2A Washington, DC 20555 U. S. Nuclear Regulatory Commission ATTN: Robert J. Fretz Jr.
Mail Stop OWFN/4A15A 11555 Rockville Pike Rockville, MD 20852-2378 U. S. Nuclear Regulatory Commission ATTN: Robert L. Dennig Mail Stop OWFN/10E1 11555 Rockville Pike Rockville, MD 20852-2378 NRC Senior Resident Inspector Pilgrim Nuclear Power Station Mr. John Giarrusso Jr.
Planning, Preparedness & Nuclear Section Chief Mass. Emergency Management Agency 400 Worcester Road Framingham, MA 01702
ATTACHMENT to PNPS Letter 2.14.004 PILGRIM NUCLEAR POWER STATION (PNPS)
NTTF RECOMMENDATION 2.3: FLOODING WALKDOWNS AVAILABLE PHYSICAL MARGIN (APM)
SUMMARY
TABLE