Seabrook Station Seabrook Station

Safety Performance in 201

&

Seabrook Station Safety in light 

Alkali-Silica Reaction Occurrin

Plant Structures Plant Structures

2011 Reactor Oversight Process

Nuclear Regulatory Commission – Reg
NRC Representatives

• Chris Miller – Director of Reactor Safet•

Arthur Burritt - Branch Chief

• William Raymond – Senior Resident Inspec• Joe DeBoer Joe DeBoer– Acting Resident Inspecto

Acting Resident Inspecto

• Meena Khanna – Branch Chief

Art Bill Joe Meena Chris
Agenda

• Introduction• Discussion of safety performance at 

Seabrook in 2011 Seabrook in 2011

• Discussion of Seabrook plant safety 

of ASR i i it t t f ASR occurring in site structures

• Closing remarks Closing remarks• NRC to address public questions
NRC Assessment Summary 

NextEra operated the plant safely

Seabrook for 2011

operated the plant safely

Seabrook remained in the Licensee Response ColumnNo substantive cross No substantive cross

-cutting issues 

cutting issues 

identified

The NRC plans to perform baseline The NRC plans to perform baseline

inspections in 2012
NRC Inspection Activities

8111 hours of ins

pection and 

Seabrook for 2011

related activitiesTwo resident inspectors on site –resid t f i ti iden

ts perform inspections 

daily and can respond to plant events at any timeThree team inspections

License Renewal InspectionT i i l Fi P t ti T

riennial Fire 

Pro

tection 

Operational 

Safety 

And

Review

Team
Seabrook PIs and Findin

g

s

January 1 through December 31, 2

All Green PerformancIndicatorsSeven Green findings 

Maintenance Rule strusystems and componemonitoringOperability determinatControl of transient coReactor trip
2011 Seabrook

Assessment Summary

Licensee 

Response

Regulatory 

Response

Degraded 

Cornerstone

Multiple Repetitive 

Degraded 

Cornerstone

Unaccepta

Performan

All Inputs are 

Green;

1 or 2 White 

Inputs;

2 White or 1 Yellow 

Input; Cornerstone

Multiple Yellow Inputs 

or 1 Red Input;

Overall Unacce

Green; Performance; 

Cornerstone 

Objectives 

Fully Met

Inputs;

Cornerstone 

Objectives 

Fully Met

Input; Cornerstone

Objectives Met w/ 

Moderate 

Degradation in 

Safety 

Performance

or 1 Red Input;

Cornerstone 

Objectives Met w/ 

Significant 

Degradation in Safety 

Performance 

Performance; 

not permitte

Operate w/in 

Column; 

Unacceptable 

to Safety

• Seabrook was operated safely• Licensee Response column of the Action M• Baseline inspections planned for 2011
S b k St ti S f t i li ht 

Sea

broo

k St

ation 

S

a

f

e

ty in li

ght 

Alkali-Silica Reaction Occurrin

Plant Structures

2011 Reactor Oversight Process

Nuclear Regulatory Commission – Reg
Alkali-Silica Reaction (ASR)

What is ASR?

• ASR is a slow chem

in concrete, which presence of water, alkaline cement ansilica found in some 

• ASR forms a gel th

causing micro causing micro

-crac

crac

concrete properties

ASR Gel Ring

Reactive Aggregate

Gel Ring

Cracking through Aggregate
Alkali-Silica Reaction 

( ) ASR

)

Where is ASR Confirmed to be Occat Seabrook? at Seabrook?

• Affected Structures 

include:

– B Electrical tunnel– Containment 

enclosure building

– RHR vault– EDG b ildi EDG

b

uilding

– EFW building
Alkali-Silica Reaction 

( ) ASR

)

• Conservative safety factors and assumptions u

Why is Seabrook Still Safe?

Conservative safety factors and assumptions u

plant design

• No significant visible deformation distortion or No significant visible deformation, distortion, or

displacement was identified in the affected struc

• No indications of rebar corrosion No indications of rebar corrosion• ASR limited to localized areas of the affec

st t ruc

tures

• ASR and the degradation it causes 

occurs sl l ow

y
Alkali-Silica Reaction (ASR)

What are the Next Steps?

• NRC continually reviews the Structural 

assessments to verify safety as more info

becomes available becomes available

• NRC ongoing inspections continue to cov

aspect f th i d th t li ts o

f the issue un

der the curren

t lice

(short term), and long term aging manage

• C di t d ff t b lti l NRC ffi Coordina

t

e

d effor

t

by multi

ple NRC offices

• Future public meeting close to site
Meeting Ground Rules

1. Please be respectful 

speaker – onl 

y one s

a time

2. S NRC t ff if 

See NRC staff if you procedural questionsor still want to sign u

3. NRC staff members 

available after the mtalk to those intereste
Contacting the NRC

• Report a safety conc

• 1-800-695-7403• allegation@nrc.g

• General questions

• www.nrc.gov• Region I Public A

• Diane Screnci, 610-33

diane.screnci@nrc.go

• Neil Sheehan, 610-33

neil.sheehan@nrc.gov