ML14129A149

05/09/2014 Fort Calhoun Station/Cooper Nuclear Station - Meeting Slide for Flood Hazard Reevaluation Report Schedule Extension Review

ML14129A149
Person / Time
Site:	Cooper, Fort Calhoun
Issue date:	05/09/2014
From:	Nebraska Public Power District (NPPD), Omaha Public Power District
To:	Joseph Sebrosky Plant Licensing Branch IV
Sebrosky J
References
Download: ML14129A149 (21)

Text

Fort Calhoun Station/Cooper Nuclear Station Flood Hazard Reevaluation Report Schedule Extension Review NRC Headquarters Rockville, MD May 9, 2014 5/6/2014 1

Agenda

• Introductions

• Purpose

• Basin Overview

• Project Scope and Schedule

• Answers to Questions from NRC Staff

• Summary

• Questions 5/6/2014 2

Introductions

• OPPD

• NPPD

• HDR and S&L

• NRC 5/6/2014 3

Meeting Purpose

• OPPD and NPPD Requests to Extend Flood Hazard Reevaluation Report (FHRR) Submittal Dates

• History

- NTTF Recommendation 2.1 Flooding

- NPPD/OPPD letters to NRC

• Unable to obtain USACE information

• Proceeding with FHRR w/o USACE information

- NRC letter to NPPD/OPPD - USACE to provide dam failure analysis input

- OPPD/NPPD FHRR extension request based on receipt of USACE analysis 5/6/2014 4

Basin Overview 5/6/2014 5

Basin Overview FCS/CNS Upstream Drainage Basins 5/6/2014 6

Project Scope Develop FHRR and supporting analysis

• Joint OPPD and NPPD contract with S&L o Calculations to be performed in accordance with 10 CFR 50 Appendix B QA Requirements o Combines the expertise of two firms S&L provides calculation packages and the FHRR in accordance with their QA requirements HDR (Non-Appendix B vendor) serves as subcontractor for Missouri River hydrologic calculations 5/6/2014 7

Project Scope

• S&L (10 CFR 50 Appendix B Approved) scope Project deliverables are calculation packages and the FHRR Local Intense Precipitation (LIP)

Debris impact forces and ice-induced flooding Appendix B review and structure for HDR calculations 5/6/2014 8

Project Scope

• HDR (Non-Appendix B vendor) subcontractor scope Probable Maximum Precipitation Probable Maximum Flood (PMF)

Dam Failure Analysis Wind Setup, Wind-Wave, Hydrostatic and Hydrodynamic Forces related to the PMF and Dam Failure Flood Site Specific Erosion Sedimentation and debris type and velocities related to the PMF and Dam Failure Missouri River Channel Geomorphic Analysis related to the dominant flood hazard 5/6/2014 9

Project Scope Final Hazard Hazard Flood Hazard Task Task Task Reevaluation Calculations Report LIP Geomorphic and Ice Wind, Wave, Hydrodynamic Flood Events 2D Detailed Forces 1D Hydraulic PMF Calculation PMF Hydraulic Flood Routing Packages Analyses Associated Effects Non Critical Dams Wind, Wave, Dam Failure Hydrodynamic Forces Dam Failure Flood Hazard USACE Dam 1D Hydraulic Calculation Reevaluation Hydrographs Flood Routing Packages Report Associated Effects 5/6/2014 10

Project Schedule (As of May 1, 2014) 5/6/2014 11

Responses to NRC Questions

• Lines discussed in the questions refer to lines in the Gantt Chart in the licensees extension request letters 5/6/2014 12

Questions from NRC Staff with Responses Q1 Part1:

Please explain how the TUFLOW 2D model (lines 8-11) results will be used versus the HEC-RAS 1D results (lines 22-27). These seem duplicative since both mention erosion/sedimentation/debris.

R1 Part 1:

Lines 8-11 are the analysis for the PMF and lines 22-27 are the analysis for the dam failure. Associated effects of erosion, sedimentation and debris impact are calculated for each hazard.

5/6/2014 13

Questions from NRC Staff with Responses Q1 Part 2:

HEC-RAS modeling was performed by USACE. Why model this reach again?

How do you expect the results to change and why?

R1 Part 2:

The ISG prescribes that the effects of the non-critical dam failures must be added to the effects of the critical dam (USACE System dams) failures to determine the flood effects at each plant location. This reach of the Missouri River was modeled to combine the hydrographs from the non-critical dams with the USACE supplied hydrograph below Gavins Point to analyze the flood effects.

We are currently running these calculation per the ISG guidance and do not have results.

5/6/2014 14

Questions from NRC Staff with Responses Q2: Wind setup-, run-up, etc on Lines 29-30 are linked to the 1D HEC-RAS model, not the TUFLOW 2D model. Please explain why this step appears to be done twice (compare with lines 14-15 under the 2D model).

R2: Items 8-11 are for the PMF Flood Hazard and items 22-27 are for the Dam Failure Flood Hazard. The wind setup-, run-up, etc. are calculated for each flood.

5/6/2014 15

Questions from NRC Staff with Responses Q3: All modeling results should be completed to observed data, such as the 2011 flood event. Please describe which events you will be using to calibrate the model, as described on line 9 for the 2D model. Also describe which line captures this step for the HEC-RAS model.

R3: The HEC-RAS Steady and Unsteady models were calibrated using data from the 2011 flood and other data from over 100 years of record at gage sites within the modeled reach of the Missouri River. The more detailed 2D hydraulic modeling also utilized high water marks in the vicinity of the sites from the 2011 flood. This is captured in Lines 4 and 7 for both FCS and CNS; both items are complete.

5/6/2014 16

Questions from NRC Staff with Responses Q4: Channel Geomorphic assessment could have been performed while waiting receipt of the USACE results. Please describe why lines 33-36 were not started earlier.

R4: The FCS and CNS Missouri River Channel Geomorphic Analyses were performed while awaiting the USACE results. Both calculations are currently undergoing technical review.

5/6/2014 17

Questions from NRC Staff with Responses Q5: Item 24, report, preparation, qa review, client review and approval is scheduled to take 3 months - dont understand the need for this time frame.

R5: An examination of the submitted schedule shows a duration for Item 24 of 38 working days or about 7.5 weeks. The preparation, review and comment resolution duration factors in the combination of two vendors and two clients.

5/6/2014 18

Questions from NRC Staff with Responses Q6: GANTT chart items 37 through 43 Major item is flooding hazard reevaluation report, and sub-items include vendor preparation, vendor review and approval, licensee technical review and comment resolution, licensee owner acceptance, licensee NRC submittal review, and NRC submittal. Time to complete these tasks is over 5 months -

seems to be an inordinate amount of time given much of the FHR is based on information supplied by the Corps.

R6: The information supplied by the USACE is one of the inputs to the flooding analyses due to the dam failure portion of the FHRs. The FHRs assess flooding from multiple sources including upstream dam failures. The current schedule allocates 7 weeks between completion of the last calculation report and issuance of the FHRR to OPPD and NPPD for technical review. Three weeks are allocated for OPPD/NPPD technical review, comment resolution and issuance of the FHRR. One month is allocated to process the FHRR submittal by each licensee. This total is less than 4 months.

5/6/2014 19

Summary

• The USACE information constitutes one input to one portion of the FHR

• Project combines expertise of a firm highly knowledgeable of the Missouri River System with a firm familiar with licensees QA requirements

• The FHR is being performed in accordance 50.54(f) letter, NRC Dam Failure ISG, and NUREG/CR-7046

• The schedule reflects activities being done in parallel to support the FHRR for each plant

• Current schedule end-date is 5 weeks earlier than previously submitted schedule 5/6/2014 20

Questions?

5/6/2014 21