ML12131A431
| 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 Seabrook Station Safety Performance in 2011 Seabrook Station Safety in light of the Alkali-Silica Reaction Occurring in Plant Structures 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 Acting Resident Inspector
- Joe DeBoer-Acting Resident Inspector
- Meena Khanna - Branch Chief Art Bill Joe Meena Chris
Agenda g
- Introduction
- Discussion of safety performance at Seabrook in 2011 Seabrook in 2011
- Discussion of Seabrook plant safety in light f ASR i
i it t
t of 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 NextEra operated the plant safely Seabrook remained in the Licensee Response Column No substantive cross-cutting issues were No substantive cross cutting issues were identified The NRC plans to perform baseline The NRC plans to perform baseline inspections in 2012
NRC Inspection Activities 8111 hours0.0939 days <br />2.253 hours <br />0.0134 weeks <br />0.00309 months <br /> of inspection and Seabrook for 2011 p
related activities Two resident inspectors on site -
id t
f i
ti residents perform inspections daily and can respond to plant events at any time Three team inspections License Renewal Inspection T i i l Fi P
t ti Triennial Fire Protection Operational Safety And Review Team 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
Response
Regulatory
Response
Degraded Cornerstone Multiple Repetitive Degraded Cornerstone Unacceptable Performance All Inputs are Green; 1 or 2 White Inputs; 2 White or 1 Yellow Input; Cornerstone Multiple Yellow Inputs or 1 Red Input; Overall Unacceptable Performance; Plants Green; 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; Plants not permitted to Operate w/in this Column; Unacceptable Margin to Safety
- Seabrook was operated safely
- Licensee Response column of the Action Matrix p
- Baseline inspections planned for 2011
S b
k St ti S f t i li ht f th Seabrook Station Safety in light of the 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 that affects causing micro cracks that affects concrete properties ASR Gel Ring Reactive Aggregate ASR Gel Ring Cracking through Aggregate
Alkali-Silica Reaction (ASR)
(
)
Where is ASR Confirmed to be Occurring at Seabrook?
at Seabrook?
- Affected Structures include:
include:
- B Electrical tunnel
- Containment enclosure building
- EDG building
- EFW building
Alkali-Silica Reaction (ASR)
(
)
- Conservative safety factors and assumptions used for Why is Seabrook Still Safe?
- Conservative safety factors and assumptions used for plant design
- No significant visible deformation distortion or
- No significant visible deformation, distortion, or displacement was identified in the affected structures No indications of rebar corrosion
- No indications of rebar corrosion
- ASR limited to localized areas of the affected t
t structures
- ASR and the degradation it causes l
l occurs slowly
Alkali-Silica Reaction (ASR)
What are the Next Steps?
- NRC continually reviews the Structural assessments to verify safety as more information becomes available becomes available
- NRC ongoing inspections continue to covering all t
f th i
d th t li aspects of the issue under the current license (short term), and long term aging management C
di t d ff t b lti l NRC ffi
- Coordinated effort by multiple NRC offices
- Future public meeting close to site
Meeting Ground Rules g
1.
Please be respectful to the k
l k
t speaker - only one speaker at a time 2
S NRC t ff if h
2.
See NRC staff if you have 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 the NRC g
- 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