ML13357A041

Public Meeting on Seabrook Station Testing Program

ML13357A041
Person / Time
Site:	Seabrook
Issue date:	12/23/2013
From:	Division of Reactor Safety I
To:
Floyd N
References
Download: ML13357A041 (24)

Text

Public Meeting Seabrook Station Alkali-Silica Reaction Testing Program December 18, 2013

Agenda

• Introductions and Opening Remarks

• Large Scale Testing Program

• Continuing NRC Oversight Activities

• License Renewal Activities

• Transition to Public Question & Answer (After ten minute break)

NRC Representatives

• David Lew - Deputy Regional Administrator

• James Trapp - Deputy Director, Division of Reactor Safety (DRS)

• Michael Marshall, Chief, Aging Management of Structures, Electrical and Systems Branch, Division of License Renewal

• Glenn Dentel - Chief, Projects Branch 3, Division of Reactor Projects (DRP)

• Mel Gray - Chief, Engineering Branch 1, DRS

• William Cook - Inspection Team Leader

Testing Program Presentation by NextEra

Continuing Regulatory Oversight Activities

• Periodic onsite inspections focused on NextEras actions to resolve the ASR non-conforming condition (PI&R Samples)

• Inspections and monitoring of NextEras large-scale specimen testing at the Ferguson Structural Engineering Laboratory, University of Texas - Austin

• Coordinate NRC Review of ASR via the Seabrook ASR Issue Technical Team (SAITT)

• Resident inspectors onsite

Continuing Regulatory Activities License Renewal Application

• Need reasonable assurance aging effects can be managed

• Recent license renewal activities concerning ASR:

June 2010 NextEra submit ted Seabrook license renewal application ML101590094 Feb 2013 Public meeting on actions/programs in application ML13066A488 Sep 2013 NextEra supplemented application ML13261A145 Nov 2013 NRC conducted license renewal audit Pending

• Remaining safety review milestones are TBD

• Safety review is ongoing

• No regulatory decision made on the application

Transition to Public Question and Answer Session

• 10 Minute Break to Set-up

Contacting the NRC

• Report a safety concern

• 1-800-695-7403

• allegation@nrc.gov

• General questions

• www.nrc.gov

• Region I Public Affairs

• Diane Screnci, 610-332-5330 diane.screnci@nrc.gov, or

• Neil Sheehan, 610-332-5331 neil.sheehan@nrc.gov

Key Points

• Seabrook Structures Remain Operable

• NextEra has detailed plans for additional research and testing

• Significant NRC oversight will continue

• Resolution of the Seabrook ASR issue will require further NRC review

Back-Up Slides SAFETY RELATED STRUCTURES REMAIN OPERABLE

• NextEras structural engineering analysis (independently reviewed by NRC team) provides reasonable assurance of adequate design (safety) margin for ASR-affected reinforced concrete structures

• No significant visible deformations, distortions, or displacement identified in affected structures

• No indications of rebar degradation

• ASR limited to localized areas of the effected structures

• ASR degradation progressed slowly

Reference Documents ADAMS Ascension Numbers

• Confirmatory Action Letter (CAL) Closure Letter, dated October 9, 2013 (ML13274A670)

• CAL Follow-Up Inspection Report No.

05000443/2012009, dated December 3, 2012 (ML12338A283)

• CAL Follow-Up Inspection Report No.

05000443/2012010, dated August 9, 2013 (ML13221A172)

CAL Follow-Up Inspection Report No.

05000443/2012009 CAL Items Closed Prompt Operability Determinations for B Electrical Tunnel and Extent of Condition identified structures (CAL Nos. 1, 5)

Interim Structural Assessment (CAL No. 3)

Completed Mortar Bar Test (CAL No. 6)

Initial six-month interval crack measurement results from 26 locations (CAL No. 10)

CAL Follow-Up Inspection Report No.

05000443/2012010 CAL Items Closed Revised the Root Cause Evaluation (CAL No. 2)

Revised the Integrated Corrective Action Plan (CAL No. 4)

Cancelled the Prism Test (CAL No. 7)

Technical details for Large-scale Beam Testing Program (CAL No. 8)

Revised the Structures Monitoring Program (CAL No. 9)

Technical details for Anchor Testing Program (CAL No. 11)

Review of open issues from IR 05000443/2012009

• Part 50.59 - this regulation outlines the processes by which a licensee may make changes to their facility, procedures, tests, experiments or evaluation methods as described in the Final Safety Analysis Report

• Part 50.90 - this regulation outlines the process by which a licensee requests an amendment to their operating license

What is ASR?

Concrete Ingredients

What is ASR?

Chemical Reaction K+ gel OH-SiO2 SiO2 forms + H2O SiO2 OH-Na+ gel alkali (in cement) silica gel forms cracking occurs reacts with silica (in as gel expands aggregate) and water 18

What is ASR?

Indications of ASR

• ASR has been identified in localized areas of Seabrook concrete structures

• ASR is a chemical reaction in concrete, which occurs over time in the presence of water, between the alkaline cement and reactive silica found in some aggregates.

• ASR forms a gel that expands causing micro-cracks that effect concrete material properties Reactive Aggregate ASR Gel Ring Cracking through Aggregate

TOUR OF PLANT Confirmed localized areas of ASR

• Effected Structures include:

- B Electrical Tunnel

- Containment Enclosure Building

- Residual Heat Removal Vault

- Emergency Diesel Generator Building

- Emergency Feedwater Building

TOUR OF PLANT 30-inch Thick Enclosure Wall Annulus area between Primary Containment and Containment Enclosure Building 48-inch Thick Containment Base Slab Wall 21

TOUR OF PLANT Other locations where ASR identified Primary Auxiliary Building VISUAL CRITERIA Pattern cracking Main Secondary deposits Steam/Feedwater Staining and discoloration Pipe Chase East Deposits of alkali silica gel Alternate Cooling Tower Service Water Pump House Containment

TOUR OF PLANT Pattern Cracking (approx. 3 ft x 3 ft area)

TOUR OF PLANT ASR Monitoring Method 24