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

{{Adams
| number = ML18025B515
| issue date = 01/25/2018
| title = Submittal of the Mitigating Strategies Assessment and Focused Evaluation for the Reevaluated Flooding Hazard
| author name = Javorik A L
| author affiliation = Energy Northwest
| addressee name = 
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000397
| license number = 
| contact person = 
| case reference number = GO2-18-010
| document type = Environmental Monitoring Report, Letter type:GO
| page count = 27
}}

=Text=
{{#Wiki_filter: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,&deg;: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
 ...........................................................
10 6.2.2 Adequate APM Justification and Reliability of Flood Protection
 ..... 10 6.2.3 Adequate Overall Site Response
 ....................................................
11 7 CONCLUSION
 .................................................................................
12 8 REFERENCES
 ..................................................................................
13 ENGNW~00460
-REPT-001 Page 4 of 14 COLUMBIA GENERATING STATION FLOODING FOCUSED EVALUATION 

==SUMMARY==

1EXECUTIVE 

==SUMMARY==

ENGNW~00460
-REPT-001 Page 5 of 14 2BACKGROUND

ENGNW~00460
-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

ENGNW~00460
-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 

ENGNW~00460
-REPT-001 Page 12 of 14 7CONCLUSION

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-REPT-001 Page 13 of 14 8REFERENCES

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