Seabrook Station

Alkali-Silica Reaction Testing Program

December 18, 2013

Public Meeting
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 NextEra’s actions 

to resolve the ASR non-conforming condition (PI&R 

Samples)

• Inspections and monitoring of NextEra’s 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:

• Remaining safety review milestones are TBD

• Safety review is ongoing

• No regulatory decision made on the application

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
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

• NextEra’s 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 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

CAL Follow-Up Inspection Report No. 

05000443/2012010
• 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
18

What is ASR?

Chemical Reaction

alkali (in cement) 

reacts with silica (in 

aggregate) and 

water

silica gel forms

K

+

Na+

cracking occurs 

as gel expands

gel

gel

SiO2

SiO2

SiO2

OHOHforms + H2O
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

ASR Gel Ring

Reactive Aggregate

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
Annulus area 

between Primary 

Containment and 

Containment 

Enclosure Building

21

Base Slab

30-inch Thick 

Enclosure Wall 

48-inch Thick 

Containment 

Wall

TOUR OF PLANT
TOUR OF PLANT

Other locations where ASR identified

 Primary Auxiliary 

Building

 Main 

Steam/Feedwater 

Pipe Chase East

 Alternate Cooling 

Tower

 Service Water Pump 

House

 Containment

VISUAL CRITERIA

Pattern cracking

Secondary deposits

Staining and discoloration

Deposits of alkali silica gel 
Pattern Cracking (approx. 3 ft x 3 ft area)

TOUR OF PLANT
ASR Monitoring Method

24

TOUR OF PLANT