W3F1-2014-0003, Response to Request for Additional Information Associated with Near-Term Task Force Recommendation 2.3, Flooding Walkdowns, Regarding Review of Available Physical Margin (APM) Assessments

Response to Request for Additional Information Associated with Near-Term Task Force Recommendation 2.3, Flooding Walkdowns, Regarding Review of Available Physical Margin (APM) Assessments

ML14031A164
Person / Time
Site:	Waterford
Issue date:	01/31/2014
From:	Chisum M Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
W3F1-2014-0003
Download: ML14031A164 (7)

Text

Entergy Operations, Inc.

17265 River Road Killona, LA 70057-3093 Tel 504-739-6660 Fax 504-739-6678 mchisum@entergy.com Michael Chisum Site Vice President Waterford 3 W3F1-2014-0003 January 31, 2014 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852

SUBJECT:

Response to Request for Additional Information Associated with Near-Term Task Force Recommendation 2.3, Flooding Walkdowns, Regarding Review of Available Physical Margin (APM) Assessments Waterford Steam Electric Station, Unit 3 (Waterford 3)

Docket No. 50-382 License No. NPF-38

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. ML12073A348)

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. Waterford 3 letter to NRC, Revised Flooding Walkdown Report -

Entergys 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, dated November 11, 2013 (ADAMS Accession No. ML13317A076)

4. NRC Letter, Request for Additional Information Associated with Near-Term Task Force Recommendation 2.3, Flooding Walkdowns, dated December 23, 2013 (ADAMS Accession No. ML13325A891)

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 Flooding.

W3F1-2014-0003 Page 2 Per Reference 2, the NRC endorsed Nuclear Energy Institute (NEI) 12-07, Guidelines for Performing Verification Walkdowns of Plant Flood Protection Features. By Reference 3, Waterford Steam Electric Station, Unit 3 (Waterford 3) 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 on site for future NRC audits.

Following the NRC staffs 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 4 the NRC staff has issued a request for additional information.

The purpose of this letter is to provide, by attachment, the Waterford 3 response to the request for additional information.

This submittal contains no new regulatory commitments. Should you have any questions regarding this submittal, please contact John P. Jarrell, Regulatory Assurance Manager, at (504) 739-6685.

I declare under penalty of perjury that the foregoing is true and correct. Executed on January 31, 2014.

Sincerely, MC/LEM

Attachment:

Waterford 3 Response to Flooding Walkdown RAI Regarding APM

W3F1-2014-0003 Page 3 cc: Attn: Director, Office of Nuclear Reactor Regulation U. S. NRC RidsNrrMailCenter@nrc.gov Mr. Mark L. Dapas, Regional Administrator U. S. NRC, Region IV RidsRgn4MailCenter@nrc.gov NRC Project Manager for Waterford 3 Alan.Wang@nrc.gov Michael.Orenak@nrc.gov NRC Senior Resident Inspector for Waterford 3 Marlone.Davis@nrc.gov

Attachment to W3F1-2014-0003 Waterford 3 Response to Flooding Walkdown RAI Regarding APM

Attachment to W3F1-2014-0003 Page 1 of 3 RAI Responses Associated with Near-Term Task Force Recommendation 2.3, Flooding Walkdowns, Regarding Review of Available Physical Margin (APM) Assessments RAI Question Number 1: Confirmation that the process for evaluating APM was reviewed.

Response Number 1: Entergy has completed a review of the process used at Waterford Steam Electric Station, Unit 3 (WF3) to evaluate APMs.

RAI Number Question 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 Number 2: The original walkdown effort followed the guidance provided in NEI 12-07 and this RAI, including a definition for a small margin.

RAI Question Number 3: If changes are necessary, a general description of any process changes to establish this consistency.

Response Number 3: As stated above, the original walkdown effort followed the guidance provided in NEI 12-07 and this RAI for the applicable flood protection features, including a definition for a small margin. No changes are necessary.

RAI Question 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.

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

Attachment to W3F1-2014-0003 Page 2 of 3 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.

• Report the APM as "undetermined" and provide the CAP reference in the RAI response.

Response Number 4: Approach B, as described above, was used to determine the APM values for seals. No interim actions are necessary.

Attachment to W3F1-2014-0003 Page 3 of 3

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, Accession No. ML12073A348.

(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, Accession No. ML12144A142.

(3) Entergy letter to NRC, Revised Flooding Walkdown Report - Entergys 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, dated 11/11/13, Accession No. ML13317A076 (4) NRC Letter, Request for Additional Information Associated with Near-Term Task Force Recommendation 2.3, Flooding Walkdowns; dated December 23, 2013, Accession No. ML13325A891