GO2-18-010, Submittal of the Mitigating Strategies Assessment and Focused Evaluation for the Reevaluated Flooding Hazard

Submittal of the Mitigating Strategies Assessment and Focused Evaluation for the Reevaluated Flooding Hazard

ML18025B515
Person / Time
Site:	Columbia
Issue date:	01/25/2018
From:	Javorik A Energy Northwest
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GO2-18-010
Download: ML18025B515 (27)

Text

G02-18-010 Page 2 of 2 documented in Reference 3 and summarized the results in Table 1. Table 2 of Reference 3 describes the reevaluated flood hazards that exceed the current design basis. Reference 3 required Columbia to perform a mitigating strategies assessment (MSA) of the reevaluated flood hazards that exceed the current design basis and stated that based on the guidance provided in Revision 2 of NEI 12-06, flood event duration parameters and applicable flood associated effects should be considered as part of the MSA. Reference 3 stated that Columbia is also expected to submit an integrated assessment (IA) or a focused evaluation (FE), as appropriate, to address the reevaluated flood hazards identified in Table 2. Enclosure 1 of this letter provides Columbia's flooding MSA and Enclosure 2 of this letter provides Columbia's FE. Both were performed using the using the guidance identified in Reference

3. No new commitments are identified in this letter. If you have any questions or require additional information, please contact Ms. L. L. Williams at (509) 377-8148. I declare under penalty of perjury that the foregoing is true and correct. Executed on the 2 5 /l,day of .;-;;n<<a f' J , 2018 Respectfully, A L. Javori Vice President, Engineering Enclosures As stated cc: NRC RIV Regional Administrator NRC NRR Project Manager NRC Senior Resident lnspector/988C CD Sonoda -BPA/1399 (email) WA Horin -Winston & Strawn

.c ENERCON , , PROJECT REPORT COVER SHEET PAGE 1 OF 9 Exceflence-fve r y pro1ecr Every doy. Title: REPORT NO.: ENGNW-00460-REPT-002 MITIGATING STRATEGIES ASSESSMENT FOR FLOODING DOCUMENTATION REQUIREMENTS REVISION:

0 AT COLUMBIA GENERATING STATION Client: Energy Northwest Project Identifier:

ENGNW-00460 Item Cover Sheet Items Yes No 1 Does this Project Report contain any open assumptions , including preliminary information that require confirmation? (If YES, identify the assumptions.)

D 2 Does this Project Report supersede an existing Project Report? (If YES , identify the superseded Project Report.) D Superseded Project Report No. Scope of Revision:

Initial Issue Revision Impact on Results: N/A Safety-Related D Non-Safety-Related Originator:

Brian Froese ~f-------Design Verifier 1 (Reviewer for Non-Safety-Related):

Dora Garcia ~~1!1~-w ~y Digital1y~gnedbyAnuG.1ur SME Reviewer:

Anu Gaur ON: cn.=AnuGaur,o:fne-rconServlctslnc

., OtJ:P rojectM.inager , email~au r@enercon.com, c:US ---Dat e: 2017.11.2809

1 8: 40-06'00' Approver:

Jared Monroe Date: 11/29/2017 I ( .. Note 1: Design Venf1cat1on 1s required for all safety-related Proiect Reports. A review 1s adequate for safety-related Project Reports.

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f,°:d ENERCON PROJECT REPORT COVER SHEET PAGE 1 OF 14 E:.x,;ell~r.c

~-~vt 1 y p rojt r:: l:.vrry d oy Title: REPORT NO.: ENGNW-00460-REPT

-001 COLUMBIA GENERATING STATION FLOODING REVISION:

0 FOCUSED EVALUATION

SUMMARY

Client: Energy Northwest Project Identifier:

ENGNW-00460 Item Cover Sheet Items Yes No 1 Does this Project Report contain any open assumptions , including prelim i nary information that require confirmation? (If YES , identify the assumptions

.) D 2 Does this Project Report supersede an existing Project Report? (If YES , identify the superseded Project Report.) Superseded Project Report No. D Scope of Revision:

Initial Issue Revision Impact on Results: N/A Safety-Related D Non-Safety-Related Originator:

Brian Froese ,t:_ ------Design Verifier 1 (Reviewer for Non-Safety-Related):

Mickey Hamby /Ju. '_/,/_ ()_J -..-,--,,,--/ SME Reviewer:

Freddy Dahmash Approver:

Jared Monroe ~-I Date: 11/29/2017 r / -\ .. Note 1: Design Venf1cat1on 1s required for all safety-related ProJect Reports. A review 1s adequate for safety-related Project Reports.

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-REPT-001 Page 3 of 14 TABLE OF CONTENTS 1 EXECUTIVE

SUMMARY

..................................................................... 4 2 BACKGROUND

................................................................................. 5 3 TERMS AND DEFINITIONS ................................................................ 6 4 FLOOD HAZARD PARAMETERS FOR UNBOUNDED MECHANISMS

..... 7 5 OVERALL SITE FLOODING RESPONSE

................................................ 8

5.1 DESCRIPTION

OF OVERALL SITE FLOODING RESPONSE .......................... 8 5.2

SUMMARY

OF PLANT MODIFICATIONS AND CHANGES .......................... 8 6 FLOOD IMPACT ASSESSMENT

.......................................................... 9 6.1 LOCAL INTENSE PRECIPITATION

- PATH 2 .......................................... 9 6.1.1 Description of Flood Impact

............................................................. 9 6.1.2 Adequate APM Justification and Reliability of Flood Protection

....... 9 6.1.3 Adequate Overall Site Response

....................................................

10 6.2 STREAMS AND RIVERS - PATH 2 ...................................................

10 6.2.1 Description of Flood Impact

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10 6.2.2 Adequate APM Justification and Reliability of Flood Protection

..... 10 6.2.3 Adequate Overall Site Response

....................................................

11 7 CONCLUSION

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12 8 REFERENCES

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13 ENGNW~00460

-REPT-001 Page 4 of 14 COLUMBIA GENERATING STATION FLOODING FOCUSED EVALUATION

SUMMARY

1EXECUTIVE

SUMMARY

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-REPT-001 Page 5 of 14 2BACKGROUND

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-REPT-001 Page 6 of 14 3TERMS AND DEFINITIONS ENGNW~00460

-REPT-001 Page 7 of 14 4FLOOD HAZARD PARAMETERS FOR UNBOUNDED MECHANISMS

Table 1 - Unbounded Flood Mechanisms

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-REPT-001 Page 8 of 14 5OVERALL SITE FLOODING RESPONSE

5.1DESCRIPTION

OF OVERALL SITE FLOODING RESPONSE 5.2

SUMMARY

OF PLANT MODIFICATIONS AND CHANGES ENGNW~00460

-REPT-001 Page 9 of 14 6FLOOD IMPACT ASSESSMENT 6.1LOCAL INTENSE PRECIPITATION

- PATH 2 6.1.1Description of Flood Impact 6.1.2Adequate APM Justification and Reliability of Flood Protection

ENGNW~00460

-REPT-001 Page 10 of 14 6.1.3Adequate Overall Site Response 6.2STREAMS AND RIVERS - PATH 2 6.2.1Description of Flood Impact 6.2.2Adequate APM Justification and Reliability of Flood Protection

Table 2 - Local Drainage Basin PMF APM ENGNW~00460

-REPT-001 Page 11 of 14 6.2.3Adequate Overall Site Response

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-REPT-001 Page 12 of 14 7CONCLUSION

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-REPT-001 Page 13 of 14 8REFERENCES

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