ML15231A397
| ML15231A397 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 08/10/2015 |
| From: | Diane Jackson Office of New Reactors |
| To: | Mohamed Shams Office of Nuclear Reactor Regulation |
| References | |
| TAC MF5231, TAC MF5233 | |
| Download: ML15231A397 (10) | |
Text
1 NRR-PMDAPEm Resource From:
Jackson, Diane Sent:
Monday, August 10, 2015 5:31 PM To:
Shams, Mohamed Cc:
DiFrancesco, Nicholas; Wyman, Stephen; Spence, Jane; Devlin-Gill, Stephanie; Roche, Kevin; Yee, On; Rivera-Lugo, Richard; Patterson, Malcolm; Hoang, Dan; Le, Tuan; David Heeszel (david.heeszel@gmail.com); 50.54f_Seismic Resource; RidsNroDsea Resource
Subject:
CALVERT CLIFFS NUCLEAR POWER PLANT - TECHNICAL REVIEW CHECKLIST RELATED TO INTERIM ESEP SUPPORTING IMPLEMENTATION OF NTTF R2.1, SEISMIC (TAC NOS. MF5231 AND MF5232)
Attachments:
Calvert Cliffs R2.1 seismic ESEP NRC review.docx August 10, 2015 MEMORANDUM TO: Mohamed K. Shams, Chief Hazards Management Branch (JHMB)
Japan Lessons-Learned Division Office of Nuclear Reactor Regulation FROM: Diane T. Jackson, Chief Geosciences and Geotechnical Engineering Branch 2 (RGS2)
Division of Site Safety and Environmental Analysis Office of New Reactors
SUBJECT:
CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 AND 2 - TECHNICAL REVIEW CHECKLIST RELATED TO INTERIM EXPEDITED SEISMIC EVALUATION PROCESS SUPPORTING IMPLEMENTATION OF NTTF RECOMMENDATION 2.1, SEISMIC, RELATED TO THE FUKUSHIMA DAI-ICHI NUCLEAR POWER PLANT ACCIDENT (TAC NOS. MF5231 AND MF5233)
The NRC technical staff working through the Geosciences and Geotechnical Engineering Branches 1 and 2 (RGS1 and RGS2) completed the Technical Review Checklist of the CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 AND 2 response to Enclosure 1, Item (6) of the March 12, 2012, request for information letter issued per Title 10 of the Code of Federal Regulations, Subpart 50.54(f), to power reactor licensees and holders of construction permits requesting addressees to provide further information to support the NRC staffs evaluation of regulatory actions to be taken in response to Fukushima Near-Term Task Force (NTTF)
Recommendation 2.1: Seismic which implements lessons learned from Japans March 11, 2011, Great Thoku Earthquake and subsequent tsunami. This addresses the staff review of the interim Expedited Seismic Evaluation Process (ESEP) report in response to Requested Item (6) of Enclosure 1, Recommendation 2.1:
Seismic, of the 50.54(f) letter. Attached is a file containing the technical review checklist to prepare a response letter to the licensee.
The NRC staff reviewed the information provided and, as documented in the enclosed staff checklist, determined that sufficient information was provided to be responsive to this portion of the Enclosure 1 of the 50.54(f) letter. The application of this staff review is limited to the interim ESEP as part of NTTF R2.1: Seismic activities.
This electronic memo constitutes the DSEA concurrence provided that only editorial changes are made to the staff assessment that would not affect the technical conclusions or technical context of the assessment.
This concludes the NRCs efforts associated with TAC NOS. MF5231 and MF5233 for the review of the interim ESEP report for the CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 AND 2.
Docket Nos: 50-317 and 50-318 CONTACT: Stephanie Devlin-Gill Office of New Reactors 301-415-5301 Copy: Nicholas DiFrancesco, Steve Wyman, Jane Spence, Stephanie Devlin-Gill, Kevin Roche, On Yee, Richard Rivera-Lugo, Malcolm Patterson, Dan Hoang, Tuan Le, David Heeszel, 50.54f Seismic Resource, RidsNroDsea Resource
Hearing Identifier:
NRR_PMDA Email Number:
2310 Mail Envelope Properties (e1a969a3465c45db9ee370b6c697e006)
Subject:
CALVERT CLIFFS NUCLEAR POWER PLANT - TECHNICAL REVIEW CHECKLIST RELATED TO INTERIM ESEP SUPPORTING IMPLEMENTATION OF NTTF R2.1, SEISMIC (TAC NOS. MF5231 AND MF5232)
Sent Date:
8/10/2015 5:31:22 PM Received Date:
8/10/2015 5:31:23 PM From:
Jackson, Diane Created By:
Diane.Jackson@nrc.gov Recipients:
"DiFrancesco, Nicholas" <Nicholas.DiFrancesco@nrc.gov>
Tracking Status: None "Wyman, Stephen" <Stephen.Wyman@nrc.gov>
Tracking Status: None "Spence, Jane" <Jane.Spence@nrc.gov>
Tracking Status: None "Devlin-Gill, Stephanie" <Stephanie.Devlin-Gill@nrc.gov>
Tracking Status: None "Roche, Kevin" <Kevin.Roche@nrc.gov>
Tracking Status: None "Yee, On" <On.Yee@nrc.gov>
Tracking Status: None "Rivera-Lugo, Richard" <Richard.Rivera-Lugo@nrc.gov>
Tracking Status: None "Patterson, Malcolm" <Malcolm.Patterson@nrc.gov>
Tracking Status: None "Hoang, Dan" <Dan.Hoang@nrc.gov>
Tracking Status: None "Le, Tuan" <Tuan.Le@nrc.gov>
Tracking Status: None "David Heeszel (david.heeszel@gmail.com)" <david.heeszel@gmail.com>
Tracking Status: None "50.54f_Seismic Resource" <50.54f_Seismic.Resource@nrc.gov>
Tracking Status: None "RidsNroDsea Resource" <RidsNroDsea.Resource@nrc.gov>
Tracking Status: None "Shams, Mohamed" <Mohamed.Shams@nrc.gov>
Tracking Status: None Post Office:
HQPWMSMRS07.nrc.gov Files Size Date & Time MESSAGE 3131 8/10/2015 5:31:23 PM Calvert Cliffs R2.1 seismic ESEP NRC review.docx 48622 Options Priority:
Standard Return Notification:
No Reply Requested:
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Recipients Received:
TECHNICAL REVIEW CHECKLIST BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO EXPEDITED SEISMIC EVALUATION PROCESS INTERIM EVALUATION IMPLEMENTING NTTF RECOMMENDATION 2.1 SEISMIC CALVERT CLIFFS NUCLEAR POWER PLANT, UNITS 1 AND 2 DOCKET NOS. 050-317 AND 050-318 By letter dated March 12, 2012 (USNRC, 2012a), the U.S. Nuclear Regulatory Commission (NRC) issued a request for information to all power reactor licensees and holders of construction permits in active or deferred status, pursuant to Title 10 of the Code of Federal Regulations (10 CFR), Section 50.54(f) Conditions of License (hereafter referred to as the 50.54(f) letter). Enclosure 1 of the 50.54(f) letter requests addressees to reevaluate the seismic hazard at their site using present-day methods and guidance for licensing new nuclear power plants, and identify actions to address or modify, as necessary, plant components affected with the reevaluated seismic hazards. Requested Information Item (6) in Enclosure 1 to the 50.54(f) letter requests addressees to provide an interim evaluation and actions taken or planned to address a higher seismic hazard relative to the design basis, as appropriate, prior to completion and submission of the seismic risk evaluation.
Additionally, by letter dated April 12, 20131, the Electric Power Research Institute (EPRI) staff submitted EPRI TR 3002000704 Seismic Evaluation Guidance: Augmented Approach for the Resolution of Fukushima Near-Term Task Force (NTTF) Recommendation 2.1: Seismic (hereafter referred to as the guidance). The Augmented Approach proposed that licensees would use an Expedited Seismic Evaluation Process (ESEP) to address the interim actions as requested by Information Item (6) in the 50.54(f) letter. The ESEP is a simplified seismic capacity evaluation with a focused scope of certain key installed Mitigating Strategies equipment that is used for core cooling and containment functions to cope with scenarios that involve a loss of all AC power and loss of access to the ultimate heat sink to withstand the Review Level Ground Motion, which is up to two times the safe shutdown earthquake (SSE).
Due to the expedited and interim nature of the ESEP, the assessment does not include many considerations that are part of a normal risk evaluation. These deferred items, include but are not limited to, structures, piping, non-seismic failures, and operator actions, as well scenarios such as addressing loss of coolant accidents. By letter dated May 7, 20132, the NRC staff endorsed the guidance. Central and eastern United States licensees with a reevaluated seismic hazard exceeding the SSE submitted an ESEP interim evaluation in December 2014.
Consistent with the interim nature of this activity, the staff performed the review of the licensees submittal to assess whether the intent of the guidance was implemented. A multi-disciplined team checked whether the identified methods were consistent with the guidance. A senior expert panel reviewed the teams questions, if any, and checklist for consistency and scope.
New or updated parameters (e.g., In-Structure Response Spectra, High Confidence of Low Probability of Failure calculations) presented by the licensees were assessed only based on licensee statements for acceptability for the Item (6) response. The application of this staff review is limited to the ESEP interim evaluation as part of NTTF R2.1: Seismic activities.
1 ADAMS Accession No. ML13102A142 2 ADAMS Accession No. ML13106A331
NTTF Recommendation 2.1 Expedited Seismic Evaluation Process Technical Review Checklist for Calvert Cliffs Nuclear Power Plant, Units 1 and 2 2
By letter dated December 17, 2014,3 Calvert Cliffs Nuclear Power Plant, LLC (the licensee) provided an Expedited Seismic Evaluation Process (ESEP) report in a response to Enclosure 1, Requested Information Item (6) of the 50.54(f) letter, for the Calvert Cliffs Nuclear Power Plant, Units 1 and 2 (Calvert Cliffs).
I.
Review Level Ground Motion The licensee:
described the determination of the review level ground motion (RLGM) using one of the means acceptable by the guidance identified location of the control point and is consistent with March 2014 Seismic Hazard and Screening submittal compared the site ground motion response spectra used to select the ESEP RLGM to the SSE.
Yes Yes Yes Calvert Cliffs used a scaled SSE at a ratio of 1.17 Notes from the Reviewer: None Deviation(s) or Deficiency(ies), and Resolution:
No deviations or deficiencies were identified.
The NRC staff concludes:
the licensees RLGM meets the intent of the guidance the RLGM is reasonable for use in the interim evaluation Yes Yes II.
Selection of the Success Path The licensee:
described the success path described normal and desired state of the equipment for the success path ensured that the success path is consistent with the plants overall mitigating strategies approach or provided a justification for an alternate path stated that the selection process was in accordance with the guidance or meets the intent of the guidance used installed FLEX Phase 1 equipment as part of the success path included FLEX Phase 2 and/or 3 connections considered installed FLEX Phase 2 and/or 3 equipment Yes Yes Yes Yes Yes Yes Yes Notes from the Reviewer: None Deviation(s) or Deficiency(ies), and Resolution:
No deviations or deficiencies were identified.
The NRC staff concludes that:
the selected success path is reasonable for use in the interim evaluation the licensee considered installed Phase 2 and 3 connections or equipment in the interim evaluation.
Yes Yes 3 ADAMS Accession No. ML14365A138
NTTF Recommendation 2.1 Expedited Seismic Evaluation Process Technical Review Checklist for Calvert Cliffs Nuclear Power Plant, Units 1 and 2 3
III.
Selection of the Equipment List The licensee:
developed and provided the ESEL by applying the ESEP identified equipment considering the following functions:
o Core cooling (with focus on Mode 1) function o Available, sustainable water source o Containment function and integrity Yes Yes Yes Yes Notes from the Reviewer: None Deviation(s) or Deficiency(ies), and Resolution:
No deviations or deficiencies were identified.
For PWR Plants ONLY The licensee included indicators / instrumentation for the following functions: level, pressure, temperature, that would be indicative of (but not explicitly identified to specific instruments): water level of the steam generator (SG), pressure of SG, containment, and reactor coolant system (RCS); and temperature of the RCS..
Yes For BWR Plants ONLY The licensee considered indicators for the following functions:
level, pressure, temperature that would be indicative of (but not explicitly identified to specific instruments): Temperature of suppression pool, RCS, containment); Pressure of suppression pool, RCS, and drywell; water level of the suppression pool.
N/A Notes from the Reviewer: None Deviation(s) or Deficiency(ies), and Resolution:
No deviations or deficiencies were identified.
Through a sampling of the ESEP key components, the NRC staff concludes that:
the licensees process to develop the ESEL meets the intent of the guidance for the interim evaluation the desired equipment state for the success path were identified the licensee considered the support equipment for the ESEL both front-line and support systems appeared to be included in the ESEL as evidenced by inclusion of SSCs on the success path and of support systems (e.g., batteries, motor control center, inverters).
Yes Yes Yes Yes IV.
Walkdown Approach The licensee:
described the walkdown screening approach, including walkbys and walkdowns performed exclusively for the ESEP, in accordance with the guidance credited previous walkdown results, including a description of current action(s) to verify the present equipment condition and/or configuration (e.g., walk-bys), in accordance with the guidance stated that the walkdown was performed by seismically trained personnel Yes Yes Yes
NTTF Recommendation 2.1 Expedited Seismic Evaluation Process Technical Review Checklist for Calvert Cliffs Nuclear Power Plant, Units 1 and 2 4
Notes from the Reviewer: None Deviation(s) or Deficiency(ies), and Resolution:
No deviations or deficiencies were identified.
The licensee:
described, if needed, adverse material condition of the equipment (e.g., material degradation) credited previous walkdown results, included a description of current action(s) to verify the present equipment condition (e.g., walk-bys), meeting the intent of the guidance Yes Yes The licensee:
described the conditions of structural items considered for the interim evaluation, including:
o spatial interactions (i.e. interaction between block walls and other items/components) o anchorage o piping connected to tanks (i.e. differential movement between pipes and tanks at connections)
Yes Yes Yes Notes from the Reviewer: None Deviation(s) or Deficiency(ies), and Resolution:
No deviations or deficiencies were identified.
The licensee reported no deviations for Calvert Cliffs.
Any deviations identified were addressed, and there is a discussion of how the deficiencies will be addressed in the ESEP submittal report.
N/A The NRC staff concludes that:
the licensee described the performed walkdown approach, including any credited previous efforts (e.g., Individual Plant Examination of External Events(IPEEE) consistent with the guidance the licensee addressed identified deviations consistent with the guidance, if any Yes N/A
NTTF Recommendation 2.1 Expedited Seismic Evaluation Process Technical Review Checklist for Calvert Cliffs Nuclear Power Plant, Units 1 and 2 5
V.
Capacity Screening Approach and HCLPF Calculation Results The licensee:
described the capacity screening process for the ESEL items, consistent with the guidance (e.g., use of EPRI NP-6041 screening table) presented the results of the screened-out ESEL items in the ESEP report described the development of in-structure response spectra (ISRS) based on scaling described the development of ISRS based on new analysis consistent with the guidance described the method for estimating HCLPF capacity of screened-in ESEL items, including both structural and functional failure modes consistent with the guidance:
o use of Conservative Deterministic Failure Margin (CDFM) o use of fragility analysis (FA) o use of experience data or generic information credited IPEEE spectral shape for HCLPF capacity estimates is similar to or envelopes the RLGM, and anchored at the same control point presented the results of HCLPF capacities including associated failure modes for screened-in ESEL items reviewed the ESEL items with the lowest HCLPF values to ensure that their capacities are equal or greater than the RLGM Yes Yes Yes N/A Yes Yes N/A Yes N/A Yes Yes Notes from the Reviewer:
The staff requested clarification regarding the methodology followed to screen out components in the ESEL using SMA analysis and seismic review team (SRT) analysis.
In the response dated June 18, 2015 (ML15218A411), the licensee explained the difference between the methods and clarified that this was a quantitative analysis performed by the SRT based on previous design basis calculations to ensure that each component has sufficient margin to address the 17% increase between the RLGM and the SSE. The staff finds the approach acceptable and determined that the intent of the guidance was met for the purposes of this interim evaluation.
The staff requested clarification regarding the analysis method used for those items located above 40 ft and the considerations taken. The methodology followed by the licensee was performed in accordance with guidance NP 6041-SL, as explained in the licensees response dated June 18, 2015 (ML15218A411). The staff finds the approach acceptable and determined that the intent of the guidance was met for the purposes of this interim evaluation.
Deviation(s) or Deficiency(ies), and Resolution:
No deviations or deficiencies were identified.
NTTF Recommendation 2.1 Expedited Seismic Evaluation Process Technical Review Checklist for Calvert Cliffs Nuclear Power Plant, Units 1 and 2 6
The NRC staff concludes that:
the licensee described the implementation of the capacity screening process consistent with the intent of the guidance the licensee presented capacity screening and calculation results, as appropriate, in the ESEP report the method used to develop the ISRS is consistent with guidance for use in the ESEP for HCLPF calculations, the licensee used HCLPF calculation methods as endorsed in the guidance no anomalies were noted in the reported HCLPF Yes Yes Yes Yes Yes VI.
Inaccessible Items The licensee:
provided a list of inaccessible items provided a schedule of the planned walkdown and evaluation for all inaccessible items provided Regulatory Commitment to complete walkdowns.
Yes N/A N/A Calvert Cliffs will provide results or complete walkdown by: N/A N/A Notes from the Reviewer:
- 1. The staff requested clarification on which ESEL items were inaccessible and to provide additional detail for making similarity determinations. In the response dated June 18, 2015 (ML15218A411), the licensee provided the list of inaccessible items, a table summarizing the HCLPF capacity of these components, and recent 2014 and 2015 photographs used. The staff finds the response and provided information acceptable for the purposes of this interim evaluation.
Deviation(s) or Deficiency(ies), and Resolution:
No deviations or deficiencies were identified.
The NRC staff concludes that the licensee:
listed inaccessible items committed to provide the results (e.g., walkdowns, walkbys, etc) of the remaining inaccessible items consistent with the guidance substitutions, if needed, were appropriately justified Yes N/A Yes VII.
Modifications to Plant Equipment The licensee:
identified modifications for ESEL items necessary to achieve HCLPF values that bound the RLGM (excluding mitigative strategies equipment (FLEX)), as specified in the guidance provided a schedule to implement such modifications (if any),
consistent with the intent of the guidance provided Regulatory Commitment to complete modifications provided Regulatory Commitment to report completion of modifications.
N/A N/A N/A N/A Calvert Cliffs will:
complete modifications by: N/A report completion of modifications by: N/A
NTTF Recommendation 2.1 Expedited Seismic Evaluation Process Technical Review Checklist for Calvert Cliffs Nuclear Power Plant, Units 1 and 2 7
Notes from the Reviewer:
- 1. No modifications are required as part of the ESEP.
Deviation(s) or Deficiency(ies), and Resolution:
No deviations or deficiencies were identified.
The NRC staff concludes that the licensee:
identified plant modifications necessary to achieve the target seismic capacity provided a schedule to implement the modifications (if any) consistent with the guidance N/A N/A VIII.
==
Conclusions:==
The NRC staff assessed the licensees implementation of the ESEP guidance. Due to the interim applicability of the ESEP evaluations, use of the information for another application would require a separate NRC review and approval. Based on its review, the NRC staff concludes that the licensees implementation of the interim evaluation meets the intent of the guidance. The staff concludes that, through the implementation of the ESEP guidance, the licensee identified and evaluated the seismic capacity of certain key installed Mitigating Strategies equipment that is used for core cooling and containment functions to cope with scenarios that involve a loss of all AC power and loss of access to the ultimate heat sink to withstand a seismic event up to the Review Level Ground Motion (RLGM) and thus, provides additional assurance while the plant seismic risk evaluation is being conducted. In the case of Calvert Cliffs, in accordance with the guidance, the RLGM used a scaled SSE at the ratio of 1.17. The application of this staff review is limited to the ESEP interim evaluation as part of NTTF R2.1: Seismic activities. As noted in the review checklist, the staff did not identify deviations or exceptions were taken from the guidance. The licensee did not identify any necessary modification of equipment from this evaluation.
In summary, the licensee, by implementing the ESEP interim evaluation, has demonstrated additional assurance which supports continued plant safety while the longer-term seismic evaluation is completed to support regulatory decision making. The NRC staff concludes that the licensee responded appropriately to Enclosure 1, Item (6) of the 50.54(f) letter, dated March 12, 2012, for Calvert Cliffs, Units 1 and 2.
Principal Contributors: Malcolm Patterson, Dan Hoang, On Yee, Tuan Le, David Heeszel, Richard Rivera-Lugo, Richard Morante (NRC Consultant)