ML14169A239
| ML14169A239 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear, FitzPatrick  |
| Issue date: | 06/17/2014 |
| From: | Michael Balazik Japan Lessons-Learned Division |
| To: | Ford B Entergy Nuclear Operations |
| References | |
| Download: ML14169A239 (4) | |
Text
1 NRR-PMDAPEm Resource From:
Balazik, Michael Sent:
Tuesday, June 17, 2014 5:33 PM To:
Ford, Bryan (BFord@entergy.com)
Cc:
Jackson, Diane; Munson, Clifford; Uribe, Juan; DiFrancesco, Nicholas; nmosher@entergy.com; Bamford, Peter; Pickett, Douglas; Rodriguez, Ricardo
Subject:
DRAFT RAIs for ANO Unit 1 & 2 and FitzPatrick Seismic Hazard and Screening Report Mr. Ford, By letters to the Nuclear Regulatory Commission (NRC) dated March 31, 2014 (Agencywide Documents and Management System (ADAMS) (public) Accession No. ML14090A243) and March 28, 2014 (ADAMS Accession No. ML14092A021), Entergy (the licensee), submitted for NRC review the Entergy Seismic Hazard and Screening Report (CEUS Sites), Response NRC Request for Information Pursuant to 10 CFR 50.54(f)
Regarding Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident for James A. FitzPatrick (FitzPatrick) Nuclear Power Plant and Arkansas Nuclear One (ANO), Units 1 and 2, respectively.
The NRC staff has reviewed the information provided for both FitzPartick and ANO, Units 1 and 2, and has determined that additional information is required to complete its review. The draft requests for additional information (RAIs) related to the NRC staff review are provided below.
After reviewing the draft RAIs, please contact me by email or by phone at 301-415-2856 to discuss the need for a teleconference to clarify the draft RAIs and to establish a due date for the response.
Optionally, Entergy has an opportunity to discuss the RAIs in the upcoming public meeting with the NRC on June 19, 2014. There is no staff expectation for Entergy to provide a final answer at this venue.
Respectfully, Michael Balazik Project Manager U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Japan Lesson Learned Project Directorate michael.balazik@nrc.gov l Tel: (301) 415-2856 DRAFT REQUEST FOR ADDITIONAL INFORMATION ARKANSAS NUCLEAR ONE, UNIT NO 1 & 2 JAMES A. FITZPATRICK NUCLEAR POWER PLANT SEISMIC HAZARD AND SCREENING REPORT DOCKET NOS. 50-313, 50-368, and 50-333 Arkansas Nuclear One, Unit 1 & 2
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- 1) The licensee states, in Appendix B of the submittal, that the minimum plant level high-confidence-low-probability of failure (HCLPF) for Units 1 and 2 is 0.3 peak ground acceleration (PGA). Section 2.0 of the submittal states that individual plant examination of external events (IPEEE) commitments and modifications that were required to achieve the plant level HCLPF have been completed.
For the purpose of understanding the significant IPEEE commitments made by the licensee, staff reviewed the Staff Evaluation Report (SER) for Arkansas Nuclear One, Units 1 and 2, dated February 27, 2001 (ADAMS Accession No.ML010600244). Staff noted a few potential discrepancies between the SER and the licensees technical basis for assuming a 0.3 g plant HCLPF in the screening report.
For example, SER, Table 3.5-1, reported that Emergency Diesel (ED) Fuel Tanks A/B (Units 1 &2) have HCLPFs of 0.2 g PGA (capacity controlled by bolt shear). Another example is the Unit 2 480V load switchgear which has a reported HCLPF of 0.27 g PGA (controlled by tension on the plug welds).
In addition, SER Table 7-1, Opportunities for Plant Improvements, states that the ED fuel tank bolt and 480V switchgear issues were being resolved by either making plant improvements, or determining that further plant improvements are not cost beneficial relative to the corresponding safety improvement.
Based on the above staff observations, it is not clear if the current designs of the ED fuel tank and 480V switchgear have been enhanced to have a HCLPF greater than 0.3 g PGA. In order for the staff to confirm the licensees basis for satisfying the Seismic Evaluation Guidance Screening, Prioritization and Implementation Details (SPID) prerequisites (SPID, Section 3.0), the staff requests clarification on this issue.
- 2) In Section 4.7 of Appendix B to the licensees Near Term Task Force (NTTF) Recommendation 2.1 submittal, non-seismic failures and human actions are discussed, including Reference 6.13 (Entergy Letter to NRC Arkansas Nuclear One - Units 1 and 2 Docket Nos. 50-313 and 50-368 License Nos.
DPR-51 and NPF-6 Additional Information Pertaining to GL 87-02 and 88-20, dated March 30, 1999
[0CAN039901], ADAMS Accession Number ML080070325) as an IPEEE Request for Additional Information (RAI) response on this topic. However, the subsequent text in the NTTF Recommendation 2.1 submittal that describes what the licensee did to address this topic appears to differ from the IPEEE RAI response description. Specifically, the NTTF Recommendation 2.1 submittal states that the developed fault tree took no credit for components on the IPEEE Safe Shutdown Equipment List (SSEL) in calculating a conditional core damage probability. However, the IPEEE RAI response states that the fault tree was developed by removing components not on the IPEEE SSEL and, as such, the calculation only credits the IPEEE SSEL components. Please clarify how non-seismic failures were determined to be insignificant contributors for the IPEEE seismic evaluation.
James A. FitzPatrick Nuclear Power Plant
- 1) Appendix B of the seismic hazard screening report states that criteria in Table 2-3 from Electric Power Research Institute (EPRI) NP-6041 which is intended for use with structures designed as Seismic Category I structures was applied to the Seismic Category II turbine building as a basis for screening out the turbine building from the seismic margin analysis. Justifications provided for application of EPRI NP-6041 Table 2-3 in this manner include the use of lower damping values and other constraints used in the Operating Basis Earthquake (OBE) analysis of the turbine building.
- a. The turbine building, as a Seismic Category II structure, could have been designed using local building codes. The seismic performance of buildings designed using local building codes may differ significantly compared to buildings designed in accordance with NRC guidance for Seismic Category I structures. Due to these potential differences, similar design peak ground acceleration is not considered a sufficient justification for screening. Provide additional explanation to justify the application of the EPRI NP-6041 screening criteria intended for Seismic Category I structures as applied to the Seismic Category II turbine building.
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- b. It is unclear in Appendix B what is meant by constraints used in the OBE analysis. Provide additional clarification and explanation on what is meant by constraints used in the OBE analysis and how that affects the design of the turbine building.
- c. The damping value used in the OBE analysis was not clearly indicated. Describe what was the damping value used in the OBE analysis and why is it appropriate for your site.
- 2) The submitted IPEEE HCLPF Spectrum (IHS) is anchored to a peak ground acceleration of 0.22g. The anchor of 0.22g is dependent on block wall HCLPF values. Appendix B of the seismic hazard screening report notes that EPRI NP-6041 guidance was not followed exactly in the assessment of the HCLPF of the block walls in the IPEEE seismic margin assessment. Provide a description and basis of the reassessment of the HCLPF for the modified block walls that resulted in increasing the plant HCLPF to 0.22g. Specifically, did you deviate from the EPRI NP-6041 guidance in the development of the fragilities? And, if so, describe the implications of the deviations from that guidance.
- 3) Section 3.3 of Appendix B of the seismic hazard screening report states that the full scope detailed review of relay chatter required in SPID (EPRI, 2013a) Section 3.3.1 has not been completed. The results of the review will be provided in a future submittal. However, Section 4.2, High Frequency Screening (> 10 Hz), states that above 10 Hz, the IHS exceeds the ground motion response spectra.
Therefore, a High Frequency Confirmation will not be performed. Clarify this apparent contradiction as to whether they are the same or different reports and to confirm that a review of relay chatter will be submitted as stated in Section 3.3.
Hearing Identifier:
NRR_PMDA Email Number:
1386 Mail Envelope Properties (Michael.Balazik@nrc.gov20140617173200)
Subject:
DRAFT RAIs for ANO Unit 1 & 2 and FitzPatrick Seismic Hazard and Screening Report Sent Date:
6/17/2014 5:32:31 PM Received Date:
6/17/2014 5:32:00 PM From:
Balazik, Michael Created By:
Michael.Balazik@nrc.gov Recipients:
"Jackson, Diane" <Diane.Jackson@nrc.gov>
Tracking Status: None "Munson, Clifford" <Clifford.Munson@nrc.gov>
Tracking Status: None "Uribe, Juan" <Juan.Uribe@nrc.gov>
Tracking Status: None "DiFrancesco, Nicholas" <Nicholas.DiFrancesco@nrc.gov>
Tracking Status: None "nmosher@entergy.com" <nmosher@entergy.com>
Tracking Status: None "Bamford, Peter" <Peter.Bamford@nrc.gov>
Tracking Status: None "Pickett, Douglas" <Douglas.Pickett@nrc.gov>
Tracking Status: None "Rodriguez, Ricardo" <Ricardo.Rodriguez@nrc.gov>
Tracking Status: None "Ford, Bryan (BFord@entergy.com)" <BFord@entergy.com>
Tracking Status: None Post Office:
Files Size Date & Time MESSAGE 8147 6/17/2014 5:32:00 PM Options Priority:
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