L-2014-022, 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

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

ML14057A795
Person / Time
Site:	Turkey Point
Issue date:	01/29/2014
From:	Kiley M Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2014-022
Download: ML14057A795 (4)

Text

January 29, 2014 L-2014-022 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555-0001 Re: Turkey Point Units 3 and 4 Docket Nos. 50-250 and 50-251 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. 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. ML12053A340.

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, 2012, Accession No. ML12172A038.

3. FPL Letter, L-2012-417, Response to NRC 10 CFR 50.54(f) Request for Information Regarding Near-Term Task Force Recommendation 2.3, Flooding, dated November 20, 2012, Accession No.ML12340A410

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, Florida Power & Light Company (FPL) submitted the Turkey Point 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.

Florida Power & Light Company 9760 S.W. 344th Street Homestead, FL 33035

Turkey Point Units 3 and Unit 4 L-2014-022 Docket No. 50-250 and 50-251 Page 2 of 4 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 addition information (RAI). The RAI questions and the FPL responses for Turkey Point are provided below.

RAI No. 1 Provide confirmation that the process for evaluating APM was reviewed.

FPL Response to RAI No. 1 FPL has completed a review of the process used at Turkey Point to evaluate APMs.

RAI No. 2 Provide confirmation that the APM process is now or was always consistent with the guidance in NEI 12-07 and discussed in this RAI.

FPL Response to RAI No. 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 No. 3 If changes are necessary, provide a general description of any process changes to establish this consistency.

FPL Response to RAI No. 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 and below grade walls/floors 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 No. 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.

Turkey Point Units 3 and Unit 4 L-2014-022 Docket No. 50-250 and 50-251 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.

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

FPL Response to RAI No. 4 Neither Approach A or B, as described above, was used to determine the APM values for seals and below grade walls/floors. As part of the actions taken to address this RAI, the seals and below grade walls/floors have been assigned an APM value of undetermined and have been entered into the CAP process through Action Request No.1924760 for further evaluation of their available physical margin. The disposition of the Action Request will determine the APM as part of the integrated assessment. Implementation of interim actions will be pursued, if necessary during the integrated assessment process.