ML14055A329

Indian Point Unit Number 2 and 3, 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

ML14055A329
Person / Time
Site:	Indian Point
Issue date:	02/12/2014
From:	Ventosa J A Entergy Nuclear Northeast, Entergy Nuclear Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NL-14-025
Download: ML14055A329 (5)

Text

SEntergyEntergy Nuclear Northeast Indian Point Energy Center450 Broadway, GSBP.O. Box 249Buchanan, NY 10511-0249 Tel 914 254 6700John A VentosaSite Vice President NL-14-025 February 12, 2014U.S. Nuclear Regulatory Commission ATTN: Document Control Desk11545 Rockville Pike, TWFN-2 F1Rockville, MD 20852-2738

SUBJECT:

Update to Response to NRC 10 CFR 50.54(f)

Request for Information Regarding Near-Term Task Force Recommendation 2.3, Flooding

-Reviewof Available Physical Margin (APM) Assessments Indian Point Unit Number 2 and 3Docket Nos. 50-247 and 50-286License Nos. DPR-26 and DPR-64

REFERENCES:

1 NRC Letter, Request for Information Pursuant to Title 10 of the Codeof Federal Regulations 50.54(f)

Regarding Recommendations 2.1, 2.3,and 9.3, of the Near-Term Task Force Review of Insights from theFukushima Dai-lchi Accident; dated March 12, 2012, Accession No.ML12073A348.

2 NRC Letter to Nuclear Energy Institute, Endorsement of NuclearEnergy Institute (NEI) 12-07, "Guidelines for Performing Verification Walkdowns of Plant Flood Protection Features,"

dated May 31, 2012,Accession No. ML12144A142.

3. Entergy IP2 Letter to NRC (NL-1 2-169) Regarding Flooding WalkdownReport -Entergy's Response to NRC Request for Information Pursuant to 10 CFR 50.54(f)

Regarding the Flooding Aspects ofRecommendation 2.3 of the Near-Term Task Force Review of Insightsfrom the Fukushima Dai-lchi

Accident, dated November 27, 2012.4. Entergy IP3 Letter to NRC (NL-12-170)

Regarding Flooding WalkdownReport -Entergy's Response to NRC Request for Information Pursuant to 10 CFR 50.54(f)

Regarding the Flooding Aspects ofRecommendation 2.3 of the Near-Term Task Force Review of Insightsfrom the Fukushima Dai-lchi

Accident, dated November 27, 2012.

NL-14-025 Docket Nos. 50-247 and 50-286Page 2 of 55. NRC Letter, Request for Additional Information Associated with Near-Term Task Force Recommendation 2.3, Flooding Walkdowns; datedDecember 23, 2013, Accession No. ML13325A891.

Dear Sir or MadamOn March 12,

2012, the NRC staff issued Reference 1 requesting information pursuant to Title10 of the Code of Federal Regulations, Part 50.54(f).

Enclosure 4 of that letter contains specificRequested Information associated with Near-Term Task Force Recommendation 2.3 forFlooding.

The NRC endorsed Nuclear Energy Institute (NEI) 12-07, "Guidelines for Performing Verification Walkdowns of Plant Flood Protection Features,"

dated May 31, 2012, in Reference

2. IPEC submitted the final reports for Indian Point 2 (IP2) and Indian Point 3 (IP3) in responseto the request for information following the approved guidance in References 3 and 4.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 issmall, and evaluate any small margins that have potentially significant consequences throughthe corrective action process.

The results of this effort were to be maintained on site for futureNRC audits.Following the NRC staff's initial review of the walkdown

reports, regulatory site audits wereconducted at a sampling of plants. Based on the walkdown report reviews and site audits, thestaff 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 IPEC responses are provided below.RAI Number 1:Provide confirmation that the process for evaluating APM was reviewed.

Response

1PEC has completed a review of the process used at IP2 and IP3 to evaluate APMs.RAI Number 2:Provide confirmation that the APM process is now or was always consistent with the guidance inNEI 12-07 and discussed in this RAI.Response:

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 theinformation provided in this RAI.

NL-14-025 Docket Nos. 50-247 and 50-286Page 3 of 5RAI Number 3.If changes are necessary, a general description of any process changes to establish thisconsistency.

Response

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 theseals associated with flood protection features.

These items have now been addressed inaccordance with the guidance provided in this RAI and entered into the corrective actionprocess, as appropriate.

An Engineering Change is being developed in accordance with siteprocesses to further evaluate the seals associated with conduits that enter the 480V switchgear rooms and provide additional mitigation measures as appropriate.

RAI Number 4:As a result of the audits and subsequent interactions with industry during publicmeetings, 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 forAPM was documented.

No further action was performed if the APM value wasgreater than the pre-established small-margin threshold value. If the APM valuewas small, an assessment of "significant consequences" was performed and theguidance 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 isassumed to be greater than the pre-established small-margin threshold value ifthe following conditions were met: (1) the APM for the barrier in which the seal islocated is greater than the small-margin threshold value and there is evidencethat the seals were designed/procured, installed, and controlled as flooding sealsin 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 todetermine that the seal configuration has been governed by the plant's designcontrol process since installation.

In this case, the APM for the seal could havebeen documented as "not small".As part of the RAI response, state if either Approach A or Approach B was used as part of theinitial walkdowns or as part of actions taken in response to this RAI. No additional actions arenecessary 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 thewalkdowns or as part of actions taken in response to this RAI), then perform the following twoactions:

NL-14-025 Docket Nos. 50-247 and 50-286Page 4 of 5* Enter the condition into the CAP (note: it is acceptable to utilize a single CAP entry tocapture this issue for multiple seals). CAP disposition of "undetermined" APM values forseals should consider the guidance provided in NEI 12-07, Section 5.8. The CAPdisposition should confirm all seals can perform their intended safety function againstfloods up to the current licensing basis flood height. Disposition may occur as part of theIntegrated Assessment.

If an Integrated Assessment is not performed, determine whether there are significant consequences associated with exceeding the capacity ofthe seals and take interim action(s),

if necessary, via the CAP processes.

These actionsdo 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

At IPEC, Approach B was utilized for the penetration seals located in the Zurn Strainer pitswhich are part of the Intake Structures.

These penetrations are shown on plant drawings andsubject to the configuration control processes should any of these penetrations and associated seals be changed.

These penetrations and seals are periodically inspected as part of thestructural maintenance rule program and were submerged during Super Storm Sandy with noobserved leakage.For the conduit seals located in the 480V switchgear rooms, neither Approach A or B, asdescribed above, was used to determine the APM values for seals. These do not have a knowncapacity but they are above the current design basis flood levels (this is river flood levels onlysince probable maximum precipitation is not a design basis) by more than a small margin. Allseals were inspected as part of the original walkdowns for signs of degradation, and corrective actions were taken, if required.

These seals are also inspected as part of the structural maintenance rule walk downs in conformance with Entergy procedures.

As part of the actionstaken to address this RAI, mitigation measures are in place at IPEC to protect vital equipment atthe site from river levels up to 17'-11,"

through strategic placement of pre-filled sandbags andtiger dams. This protection level is 2'-11" above the current design basis flood level.This letter contains no new Regulatory Commitments and no revision to existing Regulatory Commitments.

Should you have any questions regarding this submittal, please contact Mr. Robert Walpole,Manager Regulatory

Affairs, at (914) 254-6710.

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

Executed on February I ;--, 2014Sincerely, JAV/spcc: next page NL-14-025 Docket Nos. 50-247 and 50-286Page 5 of 5cc: Mr. Douglas Pickett, Senior Project Manager, NRC NRR DORLMr. William Dean, Regional Administrator, NRC Region 1NRC Resident Inspector Mr. Francis J. Murray, Jr., President and CEO, NYSERDAMs. Bridget Frymire, New York State Dept. of Public Service