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==SUBJECT:== | ==SUBJECT:== | ||
DAVIS-BESSE NUCLEAR POWER STATION, UNIT 1-INTERIM STAFF RESPONSE TO REEVALUATED FLOOD HAZARDS SUBMITTED IN RESPONSE TO 10 CFR 50.54(f) INFORMATION REQUEST-CAUSING MECHANISM REEVALUATION (TAC NO. MF3721) | |||
DAVIS-BESSE NUCLEAR POWER STATION, UNIT 1-INTERIM STAFF RESPONSE TO REEVALUATED FLOOD HAZARDS SUBMITTED IN RESPONSE TO 10 CFR 50.54(f) | |||
INFORMATION REQUEST-CAUSING MECHANISM REEVALUATION (TAC NO. MF3721) | |||
==Dear Mr. Boles:== | ==Dear Mr. Boles:== | ||
The purpose of this letter is to provide a summary of the U.S. Nuclear Regulatory Commission (NRC) staff's assessment of the re-evaluated flood-causing mechanisms described in the March 11, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 14070A 108), flood hazard reevaluation report (FHRR) submitted by FirstEnergy Nuclear Operating Company (FENOC, the licensee) for the Davis-Besse Nuclear Power Station, Unit 1 (Davis-Besse), as well as supplemental information resulting from requests for additional information and audits. By letter dated March 12, 2012, the NRC issued a request for information pursuant to Title 10 of the Code of Federal Regulations, Section 50.54(f) (hereafter referred to as the 50.54(f) letter) (ADAMS Accession No. ML 12053A340). The request was issued as part of implementing lessons-learned from the accident at the Fukushima Dai-ichi nuclear power plant. Enclosure 2 to the 50.54(f) letter requested licensees to re-evaluate flood-causing mechanisms using present-day methodologies and guidance. Concurrently, with the reevaluation of flooding hazards, licensees were required to develop and implement mitigating strategies in accordance with NRC Order EA-12-049, "Requirements for Mitigation Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML 12054A735). On March 30, 2015, the Commission provided Staff Requirements Memoranda (SRM) (ADAMS Accession No. ML 15089A236) to COMSECY-14-0037, "Integration of Mitigating Strategies for Beyond-Design-Basis External Events and the Reevaluation of Flooding Hazards," dated November 21, 2014 (ADAMS Accession No. ML 14309A256), affirming that licensees need to address the reevaluated flooding hazards within their mitigating strategies for beyond-design-basis external events. The NRC staff has reviewed the information submitted by the licensee and has summarized the results of the review in the table provided as an Enclosure to this letter. Table 1 provides the current design-basis flood hazard mechanisms. Table 2 provides reevaluated flood hazard mechanisms; however, reevaluated flood hazard mechanisms bounded by the current basis (Table 1) are not included B. Boles The NRC staff has concluded that the licensee's reevaluated flood hazards information, as summarized in the Enclosure, is suitable for the assessment of mitigating strategies developed in response to Order EA-12-049 (i.e., defines the mitigating strategies flood hazard information described in guidance documents currently being finalized by the industry and NRC staff) for Davis-Besse. Further, the NRC staff has concluded that the licensee's reevaluated flood hazard information is a suitable input for other assessments associated with Near-Term Task Force Recommendation 2.1 "Flooding". The NRC staff plans to issue a staff assessment documenting the basis for these conclusions at a later time. In addition, NEI 12-06 "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide" is currently being revised. This revision will include a methodology to perform a Mitigating Strategies Assessment (MSA) with respect to the reevaluated flood hazards. Once this methodology is endorsed by the NRC, flood duration parameters and applicable associated effects should be considered as part of the Davis-Besse MSA. The NRC staff will evaluate the flood event duration parameters (including warning time and period of inundation) and related associated effects developed by the licensee during the NRC staff's review of the MSA. As stated above, Table 2 of the enclosure to this letter describes the reevaluated flood hazards that exceed the current design-basis. In order to complete its response to the information requested by Enclosure 2 to the 50.54(f) letter, the licensee is expected to submit an integrated assessment or a focused evaluation, as appropriate, to address these reevaluated flood hazards, as described in the NRC letter, "Coordination of Request for Information Regarding Flooding Hazard Reevaluation and Mitigating Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML 15174A257). This letter describes the changes in the NRC's approach to the flood hazard reevaluations that were approved by the Commission in its SRM to COMSECY-15-0019, "Closure Plan for the Reevaluation of Flooding Hazards for Operating Nuclear Power Plants" (ADAMS Accession No. ML 15209A682). | The purpose of this letter is to provide a summary of the U.S. Nuclear Regulatory Commission (NRC) staff's assessment of the re-evaluated flood-causing mechanisms described in the March 11, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 14070A 108), flood hazard reevaluation report (FHRR) submitted by FirstEnergy Nuclear Operating Company (FENOC, the licensee) for the Davis-Besse Nuclear Power Station, Unit 1 (Davis-Besse), | ||
B. Boles If you have any questions, please contact me at (301) 415-3809 or e-mail at Juan.Uribe@nrc.gov. Docket No. 50-346 | as well as supplemental information resulting from requests for additional information and audits. By letter dated March 12, 2012, the NRC issued a request for information pursuant to Title 10 of the Code of Federal Regulations, Section 50.54(f) | ||
(hereafter referred to as the 50.54(f) letter) (ADAMS Accession No. ML 12053A340). | |||
The request was issued as part of implementing lessons-learned from the accident at the Fukushima Dai-ichi nuclear power plant. Enclosure 2 to the 50.54(f) letter requested licensees to re-evaluate flood-causing mechanisms using present-day methodologies and guidance. | |||
Concurrently, with the reevaluation of flooding | |||
: hazards, licensees were required to develop and implement mitigating strategies in accordance with NRC Order EA-12-049, "Requirements for Mitigation Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML 12054A735). | |||
On March 30, 2015, the Commission provided Staff Requirements Memoranda (SRM) (ADAMS Accession No. ML 15089A236) to COMSECY-14-0037, "Integration of Mitigating Strategies for Beyond-Design-Basis External Events and the Reevaluation of Flooding Hazards," | |||
dated November 21, 2014 (ADAMS Accession No. ML 14309A256), | |||
affirming that licensees need to address the reevaluated flooding hazards within their mitigating strategies for beyond-design-basis external events. The NRC staff has reviewed the information submitted by the licensee and has summarized the results of the review in the table provided as an Enclosure to this letter. Table 1 provides the current design-basis flood hazard mechanisms. | |||
Table 2 provides reevaluated flood hazard mechanisms; | |||
: however, reevaluated flood hazard mechanisms bounded by the current basis (Table 1) are not included B. Boles The NRC staff has concluded that the licensee's reevaluated flood hazards information, as summarized in the Enclosure, is suitable for the assessment of mitigating strategies developed in response to Order EA-12-049 (i.e., defines the mitigating strategies flood hazard information described in guidance documents currently being finalized by the industry and NRC staff) for Davis-Besse. | |||
: Further, the NRC staff has concluded that the licensee's reevaluated flood hazard information is a suitable input for other assessments associated with Near-Term Task Force Recommendation 2.1 "Flooding". | |||
The NRC staff plans to issue a staff assessment documenting the basis for these conclusions at a later time. In addition, NEI 12-06 "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide" is currently being revised. | |||
This revision will include a methodology to perform a Mitigating Strategies Assessment (MSA) with respect to the reevaluated flood hazards. | |||
Once this methodology is endorsed by the NRC, flood duration parameters and applicable associated effects should be considered as part of the Davis-Besse MSA. The NRC staff will evaluate the flood event duration parameters (including warning time and period of inundation) and related associated effects developed by the licensee during the NRC staff's review of the MSA. As stated above, Table 2 of the enclosure to this letter describes the reevaluated flood hazards that exceed the current design-basis. | |||
In order to complete its response to the information requested by Enclosure 2 to the 50.54(f) letter, the licensee is expected to submit an integrated assessment or a focused evaluation, as appropriate, to address these reevaluated flood hazards, as described in the NRC letter, "Coordination of Request for Information Regarding Flooding Hazard Reevaluation and Mitigating Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML 15174A257). | |||
This letter describes the changes in the NRC's approach to the flood hazard reevaluations that were approved by the Commission in its SRM to COMSECY-15-0019, "Closure Plan for the Reevaluation of Flooding Hazards for Operating Nuclear Power Plants" (ADAMS Accession No. ML 15209A682). | |||
B. Boles If you have any questions, please contact me at (301) 415-3809 or e-mail at Juan.Uribe@nrc.gov. | |||
Docket No. 50-346 | |||
==Enclosure:== | |||
Summary of Results of Flooding Hazard Re-Evaluation Report -ML 15238B865 cc w/encl: Distribution via Listserv Juan F. ribe, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation ENCLOSURE: | |||
SUMMARY TABLES OF REEVALUATED FLOOD HAZARD LEVELS Davis-Besse, Unit 1 Table 1. Current Design Basis Flood Hazards for Use in the MSA Mechanism I Stillwater Waves/ Design Basis Reference I I Elevation Run up Hazard Elevation Local Intense Precipitation LIP -Turbine Building 584.5 ft Minimal 584.5 ft FHRR Section 2.1.1 IGLD55 IGLD55 Streams and Rivers i River and Streams 579.0 ft Not 579.0 ft FHRR Section 2.1.2 IGLD55 applicable IGLD55 Failure of Dams and Onsite I Water Control/Storage Structures Dam Failure No Impact No Impact No Impact FHRR Section 2.1.3 Identified Identified Identified Storm Surge Storm Surge 583.7 ft 6.6 ft 590.3 ft FHRR Section 2.1.4 IGLD55 IGLD55 FHRR Section 2.1.8 ' Seiche Seiche Not included Not included Not included FHRR Table 3 in DB in DB in DB Tsunami 1 Not included Not included Not included FHRR Table 3 in DB in DB in DB I Ice-Induced Flooding No Impact No Impact No Impact FHRR Table 3 Identified Identified Identified Channel Migrations/Diversions No Impact No Impact No Impact FHRR Table 3 Identified Identified Identified Note: Reported values are rounded to the nearest one-tenth of a foot. | |||
Davis-Besse, Unit 1 Table 2. Reevaluated Flood Hazards for Flood-Causing Mechanisms for Use in the MSA Mechanism Stillwater Waves/ Reevaluated Reference Elevation Run up Hazard Elevation Local Intense Precipitation Turbine Building 585.5 ft Minimal 585.5 ft FHRR Section 3.8 IGLD55 IGLD55 Intake Structure 585.5 ft Minimal 585.5 ft FHRR Section 3.8 IGLD55 IGLD55 Auxiliary Buildings 585.4 ft Minimal 585.4 ft FHRR Table 1 IGLD55 IGLD55 Storm Surge 585.8 ft 0.1 ft 585.9 ft FHRR Section 3.7.4 IGLD55 IGLD55 i Note 1: The licensee is expected to develop flood event duration parameters and applicable flood associated effects to conduct the MSA. The staff will evaluate the flood event duration parameters (including warning time and period of inundation) and flood associated effects during its review of the MSA. Note 2: Reevaluated hazard mechanisms bounded by the current design basis (see Table 1) are not included in this table. Note 3: Reported values are rounded to the nearest one-tenth of a foot. | |||
B. Boles If you have any questions, please contact me at (301) 415-3809 or e-mail at Juan.Uribe@nrc.gov. | |||
Docket No. 50-346 | |||
==Enclosure:== | ==Enclosure:== | ||
PKG ML 152398210 LTR: ML 152398212 ENCL: ML 152388865 *via email OFFICE NRR/JLD/JHMB/PM NRR/JLD/LA N RO/DSEA/RH M2/TR* NAME JUribe Slent Mlee DATE 8127 /15 8 / 27 /15 8 / 26 /15 OFFICE NRO/DSEA/RHM2/BC* NRR/JLD/JHMB/BC NRR/JLD/JHMB/PM NAME CCook MShams JUribe DATE 8 / 26 /15 8 / 28 /15 9 / 3 /15}} | Sincerely, IRA! Juan F. Uribe, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation Summary of Results of Flooding Hazard Re-Evaluation Report cc w/encl: Distribution via Listserv DISTRIBUTION: | ||
PUBLIC JUribe, NRR RidsNrrDorllpl3-2 Resource RidsRgn3MailCenter RidsOpaMail Resource ARivera-Varona, NRO MWillingham, NRO MShams, NRR JLD R/F LQuinn-Willingham, NRO RidsNrrDorl Resource ResourceRidsNrrLA RidsAcrsAcnw_MailCtr Resource KErwin, NRO RRivera-Lugo, NRO Slent RidsNRRJLD Resource RidsNroDsea Resource RidsNrrPMLaSalle Resource RidsOgcMailCenter Resource CCook, NRO ACampbell, NRO BHarvey, NRO ADAMS Accession No.: PKG ML 152398210 LTR: ML 152398212 ENCL: ML 152388865 | |||
*via email OFFICE NRR/JLD/JHMB/PM NRR/JLD/LA N RO/DSEA/RH M2/TR* NAME JUribe Slent Mlee DATE 8127 /15 8 / 27 /15 8 / 26 /15 OFFICE NRO/DSEA/RHM2/BC* | |||
NRR/JLD/JHMB/BC NRR/JLD/JHMB/PM NAME CCook MShams JUribe DATE 8 / 26 /15 8 / 28 /15 9 / 3 /15 OFFICIAL RECORD COPY}} | |||
Revision as of 21:48, 30 June 2018
| ML15239B212 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 09/03/2015 |
| From: | Uribe J F Japan Lessons-Learned Division |
| To: | Boles B D FirstEnergy Nuclear Operating Co |
| Uribe J F, NRR/JLD, 415-3809 | |
| Shared Package | |
| ML15239B210 | List: |
| References | |
| TAC MF3721 | |
| Download: ML15239B212 (7) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. Brian D. Boles Site Vice President FirstEnergy Nuclear Operating Company c/o Davis-Besse NPS 5501 N. State Route 2 Oak Harbor, OH 43449-9760 September 3, 2015
SUBJECT:
DAVIS-BESSE NUCLEAR POWER STATION, UNIT 1-INTERIM STAFF RESPONSE TO REEVALUATED FLOOD HAZARDS SUBMITTED IN RESPONSE TO 10 CFR 50.54(f)
INFORMATION REQUEST-CAUSING MECHANISM REEVALUATION (TAC NO. MF3721)
Dear Mr. Boles:
The purpose of this letter is to provide a summary of the U.S. Nuclear Regulatory Commission (NRC) staff's assessment of the re-evaluated flood-causing mechanisms described in the March 11, 2014 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 14070A 108), flood hazard reevaluation report (FHRR) submitted by FirstEnergy Nuclear Operating Company (FENOC, the licensee) for the Davis-Besse Nuclear Power Station, Unit 1 (Davis-Besse),
as well as supplemental information resulting from requests for additional information and audits. By letter dated March 12, 2012, the NRC issued a request for information pursuant to Title 10 of the Code of Federal Regulations, Section 50.54(f)
(hereafter referred to as the 50.54(f) letter) (ADAMS Accession No. ML 12053A340).
The request was issued as part of implementing lessons-learned from the accident at the Fukushima Dai-ichi nuclear power plant. Enclosure 2 to the 50.54(f) letter requested licensees to re-evaluate flood-causing mechanisms using present-day methodologies and guidance.
Concurrently, with the reevaluation of flooding
- hazards, licensees were required to develop and implement mitigating strategies in accordance with NRC Order EA-12-049, "Requirements for Mitigation Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML 12054A735).
On March 30, 2015, the Commission provided Staff Requirements Memoranda (SRM) (ADAMS Accession No. ML 15089A236) to COMSECY-14-0037, "Integration of Mitigating Strategies for Beyond-Design-Basis External Events and the Reevaluation of Flooding Hazards,"
dated November 21, 2014 (ADAMS Accession No. ML 14309A256),
affirming that licensees need to address the reevaluated flooding hazards within their mitigating strategies for beyond-design-basis external events. The NRC staff has reviewed the information submitted by the licensee and has summarized the results of the review in the table provided as an Enclosure to this letter. Table 1 provides the current design-basis flood hazard mechanisms.
Table 2 provides reevaluated flood hazard mechanisms;
- however, reevaluated flood hazard mechanisms bounded by the current basis (Table 1) are not included B. Boles The NRC staff has concluded that the licensee's reevaluated flood hazards information, as summarized in the Enclosure, is suitable for the assessment of mitigating strategies developed in response to Order EA-12-049 (i.e., defines the mitigating strategies flood hazard information described in guidance documents currently being finalized by the industry and NRC staff) for Davis-Besse.
- Further, the NRC staff has concluded that the licensee's reevaluated flood hazard information is a suitable input for other assessments associated with Near-Term Task Force Recommendation 2.1 "Flooding".
The NRC staff plans to issue a staff assessment documenting the basis for these conclusions at a later time. In addition, NEI 12-06 "Diverse and Flexible Coping Strategies (FLEX) Implementation Guide" is currently being revised.
This revision will include a methodology to perform a Mitigating Strategies Assessment (MSA) with respect to the reevaluated flood hazards.
Once this methodology is endorsed by the NRC, flood duration parameters and applicable associated effects should be considered as part of the Davis-Besse MSA. The NRC staff will evaluate the flood event duration parameters (including warning time and period of inundation) and related associated effects developed by the licensee during the NRC staff's review of the MSA. As stated above, Table 2 of the enclosure to this letter describes the reevaluated flood hazards that exceed the current design-basis.
In order to complete its response to the information requested by Enclosure 2 to the 50.54(f) letter, the licensee is expected to submit an integrated assessment or a focused evaluation, as appropriate, to address these reevaluated flood hazards, as described in the NRC letter, "Coordination of Request for Information Regarding Flooding Hazard Reevaluation and Mitigating Strategies for Beyond-Design-Basis External Events" (ADAMS Accession No. ML 15174A257).
This letter describes the changes in the NRC's approach to the flood hazard reevaluations that were approved by the Commission in its SRM to COMSECY-15-0019, "Closure Plan for the Reevaluation of Flooding Hazards for Operating Nuclear Power Plants" (ADAMS Accession No. ML 15209A682).
B. Boles If you have any questions, please contact me at (301) 415-3809 or e-mail at Juan.Uribe@nrc.gov.
Docket No. 50-346
Enclosure:
Summary of Results of Flooding Hazard Re-Evaluation Report -ML 15238B865 cc w/encl: Distribution via Listserv Juan F. ribe, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation ENCLOSURE:
SUMMARY TABLES OF REEVALUATED FLOOD HAZARD LEVELS Davis-Besse, Unit 1 Table 1. Current Design Basis Flood Hazards for Use in the MSA Mechanism I Stillwater Waves/ Design Basis Reference I I Elevation Run up Hazard Elevation Local Intense Precipitation LIP -Turbine Building 584.5 ft Minimal 584.5 ft FHRR Section 2.1.1 IGLD55 IGLD55 Streams and Rivers i River and Streams 579.0 ft Not 579.0 ft FHRR Section 2.1.2 IGLD55 applicable IGLD55 Failure of Dams and Onsite I Water Control/Storage Structures Dam Failure No Impact No Impact No Impact FHRR Section 2.1.3 Identified Identified Identified Storm Surge Storm Surge 583.7 ft 6.6 ft 590.3 ft FHRR Section 2.1.4 IGLD55 IGLD55 FHRR Section 2.1.8 ' Seiche Seiche Not included Not included Not included FHRR Table 3 in DB in DB in DB Tsunami 1 Not included Not included Not included FHRR Table 3 in DB in DB in DB I Ice-Induced Flooding No Impact No Impact No Impact FHRR Table 3 Identified Identified Identified Channel Migrations/Diversions No Impact No Impact No Impact FHRR Table 3 Identified Identified Identified Note: Reported values are rounded to the nearest one-tenth of a foot.
Davis-Besse, Unit 1 Table 2. Reevaluated Flood Hazards for Flood-Causing Mechanisms for Use in the MSA Mechanism Stillwater Waves/ Reevaluated Reference Elevation Run up Hazard Elevation Local Intense Precipitation Turbine Building 585.5 ft Minimal 585.5 ft FHRR Section 3.8 IGLD55 IGLD55 Intake Structure 585.5 ft Minimal 585.5 ft FHRR Section 3.8 IGLD55 IGLD55 Auxiliary Buildings 585.4 ft Minimal 585.4 ft FHRR Table 1 IGLD55 IGLD55 Storm Surge 585.8 ft 0.1 ft 585.9 ft FHRR Section 3.7.4 IGLD55 IGLD55 i Note 1: The licensee is expected to develop flood event duration parameters and applicable flood associated effects to conduct the MSA. The staff will evaluate the flood event duration parameters (including warning time and period of inundation) and flood associated effects during its review of the MSA. Note 2: Reevaluated hazard mechanisms bounded by the current design basis (see Table 1) are not included in this table. Note 3: Reported values are rounded to the nearest one-tenth of a foot.
B. Boles If you have any questions, please contact me at (301) 415-3809 or e-mail at Juan.Uribe@nrc.gov.
Docket No. 50-346
Enclosure:
Sincerely, IRA! Juan F. Uribe, Project Manager Hazards Management Branch Japan Lessons-Learned Division Office of Nuclear Reactor Regulation Summary of Results of Flooding Hazard Re-Evaluation Report cc w/encl: Distribution via Listserv DISTRIBUTION:
PUBLIC JUribe, NRR RidsNrrDorllpl3-2 Resource RidsRgn3MailCenter RidsOpaMail Resource ARivera-Varona, NRO MWillingham, NRO MShams, NRR JLD R/F LQuinn-Willingham, NRO RidsNrrDorl Resource ResourceRidsNrrLA RidsAcrsAcnw_MailCtr Resource KErwin, NRO RRivera-Lugo, NRO Slent RidsNRRJLD Resource RidsNroDsea Resource RidsNrrPMLaSalle Resource RidsOgcMailCenter Resource CCook, NRO ACampbell, NRO BHarvey, NRO ADAMS Accession No.: PKG ML 152398210 LTR: ML 152398212 ENCL: ML 152388865
- via email OFFICE NRR/JLD/JHMB/PM NRR/JLD/LA N RO/DSEA/RH M2/TR* NAME JUribe Slent Mlee DATE 8127 /15 8 / 27 /15 8 / 26 /15 OFFICE NRO/DSEA/RHM2/BC*
NRR/JLD/JHMB/BC NRR/JLD/JHMB/PM NAME CCook MShams JUribe DATE 8 / 26 /15 8 / 28 /15 9 / 3 /15 OFFICIAL RECORD COPY