ML12131A431

Aam ROP-12 Slides-Safety Performance & Alkali-Silica Reaction - r9 Revised Format

ML12131A431
Person / Time
Site:	Seabrook
Issue date:	05/10/2012
From:	Arthur Burritt Reactor Projects Branch 3
To:
BURRITT, AL
References
Download: ML12131A431 (14)

Text

Seabrook Station Safety Performance in 2011 Seabrook Station Safety in light of the Alkali-Silica Reaction Occurring in Plant Structures 2011 Reactor Oversight Process Nuclear Regulatory Commission - Region I

NRC Representatives

• Chris Miller - Director of Reactor Safety

• Arthur Burritt - Branch Chief

• William Raymond - Senior Resident Inspector

• Joe DeBoer DeBoer- Acting Resident Inspector

• Meena Khanna - Branch Chief Art Bill Joe Meena Chris

Agenda g

• Introduction

• Discussion of safety performance at Seabrook in 2011

• Discussion of Seabrook plant safety in light off ASR occurring i iin site it structures t t

• Closing remarks

• NRC to address public questions

NRC Assessment Summary Seabrook for 2011 NextEra operated the plant safely Seabrook remained in the Licensee Response Column No substantive cross-cutting cross cutting issues were identified The NRC plans to perform baseline inspections in 2012

NRC Inspection Activities Seabrook for 2011 8111 hours0.0939 days <br />2.253 hours <br />0.0134 weeks <br />0.00309 months <br /> of inspection p and related activities Two resident inspectors on site -

residents id t perform f i inspections ti daily and can respond to plant events at any time Three team inspections License Renewal Inspection Ti Triennial i l Fi Fire P Protection t ti Operational Safety And Review Team

Seabrook PIs and Findings g January 1 through December 31, 2011 All Green Performance Indicators Seven Green findings related to:

Maintenance Rule structure, systems and component monitoring Operability determinations Control of transient combustibles Reactor trip

2011 Seabrook Assessment Summary Licensee Regulatory Degraded Multiple Repetitive Unacceptable Response Response Cornerstone Degraded Performance Cornerstone All Inputs are 1 or 2 White 2 White or 1 Yellow Multiple Yellow Inputs Overall Unacceptable Green; Inputs; Input; Cornerstone or 1 Red Input; Performance; Plants Cornerstone Cornerstone Objectives Met w/ Cornerstone not permitted to Objectives Objectives Moderate Objectives Met w/ Operate w/in this Fully Met Fully Met Degradation in Significant Column; Safety Degradation in Safety Unacceptable Margin Performance Performance to Safety

• Seabrook was operated safely

• Licensee Response p column of the Action Matrix

• Baseline inspections planned for 2011

Seabrook S b k St Station ti Safety S f t in i light li ht off the th Alkali-Silica Reaction Occurring in Plant Structures 2011 Reactor Oversight Process Nuclear Regulatory Commission - Region I

Alkali-Silica Reaction (ASR)

What is ASR?

• ASR is a slow chemical reaction in concrete, which occurs 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 micro cracks that affects concrete properties Reactive Aggregate ASR Gel Ring Cracking through Aggregate

Alkali-Silica Reaction (ASR)

( )

Where is ASR Confirmed to be Occurring at Seabrook?

• Affected Structures include:

- B Electrical tunnel

- Containment enclosure building

- RHR vault

- EDG building b ildi

- EFW building

Alkali-Silica Reaction (ASR) ( )

Why is Seabrook Still Safe?

• Conservative safety factors and assumptions used for plant design

• No significant visible deformation, deformation distortion distortion, or displacement was identified in the affected structures

• No indications of rebar corrosion

• ASR limited to localized areas of the affected structures t t

• ASR and the degradation it causes occurs slowly l l

Alkali-Silica Reaction (ASR)

What are the Next Steps?

• NRC continually reviews the Structural assessments to verify safety as more information becomes available

• NRC ongoing inspections continue to covering all aspects t off the th issue i under d ththe currentt license li (short term), and long term aging management

• Coordinated C di t d effort ff t by b multiple lti l NRC offices ffi

• Future public meeting close to site

Meeting g Ground Rules

1. Please be respectful to the speaker k - only l one speakerk att a time 2 S

2. See NRC stafft ff if you have h

procedural questions/concerns or still want to sign up.

3. NRC staff members will be available after the meeting to talk to those interested

Contacting g 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

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