PLA-7123, 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 PLA-7123

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 PLA-7123

ML14029A640
Person / Time
Site:	Susquehanna
Issue date:	01/29/2014
From:	Rausch T Susquehanna
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
PLA-7123
Download: ML14029A640 (4)

Text

Timothy S. Rausch PPL Susquehanna, LLC Senior Vice President & Chief Nuclear Officer 769 Salem Boulevard Berwick, PA 18603 Tel. 570.542.3345 Fax 570.542.1504 tsrausch@ pplweb.com JAN 2 9 2014 TM U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 SUSQUEHANNA STEAM ELECTRIC STATION 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 Docket Nos. 50-387 PLA-7123 and 50-388

References:

( 1) NRC Letter, "Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(]) 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 Peiforming Verification Walkdowns of Plant Flood Protection Features,"

dated May 31, 2012, Accession No. ML12144A142.

(3) PPL Letter (PLA-6938), "Response to Request for Information Pursuant to 10 CFR 50.54(])

Regarding Results of the SSES Flooding Walkdown," dated November 21, 2012.

(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.

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. 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, PPL Susquehanna, LLC (PPL) submitted the final Flooding Walkdown 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 flood protection feature, determine if the margin provided is small,

Document Control Desk PLA-7123 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 4 the NRC staff has issued a request for addition information (RAI). The RAI questions and the PPL's responses are provided below.

RAI Number 1: Confirmation that the process for evaluating APM was reviewed.

Response: PPL has completed a review of the process used at Susquehanna Steam Electric Station (SSES) 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: The original walkdown effort followed the guidance provided in NEI 12-07.

Additional actions will be 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: As stated above, the original walkdown effort followed the guidance provided in NEI 12-07. A specific APM had been assigned to the seals associated with flood protection features. However, a value for small APM was not specifically determined. This action will be 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:

Document Control Desk PLA-7123 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 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.

Document Control Desk PLA-7123

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

Response: Approach A was used to determine APM at SSES. A numerical value for APM was documented for each penetration seal in the station flood walkdown records. Penetrations with inadequate APM were entered in the corrective action process and an assessment of "significant consequences" performed.

As part of the actions taken to address this RAI, a value for small APM will be determined and the impact assessed (AR-2014-01305). Implementation of interim actions will be pursued, if necessary.

This letter contains one new Regulatory Commitment and no revision to existing Regulatory Commitments.

Regulatory Commitment Completion Date CAP Tracking Number PPL will determine a value for small 03/14/2014 AR-2014-01305 APM and assess the impact.

If you have any questions regarding the content of this letter, please contact Mr. John L. Tripoli, Manager, Nuclear Regulatory Affairs, at (570) 542-3100.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on: D \ ( 7...'7 I 2..0 I L(

T. S. Rausch Copy: J. E. Greives, NRC Sr. Resident Inspector J. A. Whited, NRC Project Manager L. J. Winker, PA DEP/BRP Region I Administrator, NRC