ML14112A323

Public Meeting Concerning Concrete Degradation Due to Alkali-Silica Reaction

ML14112A323
Person / Time
Site:	Seabrook
Issue date:	04/22/2014
From:	Ray Lorson Division of Reactor Safety I
To:	Gavutis S C-10 Research & Education Foundation
Trapp J
References
Download: ML14112A323 (4)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION REGION I 2100 RENAISSANCE BLVD., SUITE 100 KING OF PRUSSIA, PA 19406-2713 April 22, 2014 Ms. Sandra Gavutis, Executive Director C-10 Research and Education Foundation 44 Merrimac St.

Newburyport, MA 01950

SUBJECT:

SEABROOK STATION PUBLIC MEETING CONCERNING CONCRETE DEGRADATION DUE TO ALKALI-SILICA REACTION

Dear Ms. Gavutis:

I am responding to your letter dated March 10, 2014, regarding the public meeting held on December 18, 2013, to discuss concrete degradation at Seabrook Station due to Alkali-Silica Reaction (ASR). Your letter stated NextEra staff made misstatements that warranted correction by the U.S. Nuclear Regulatory Commission (NRC) managers in attendance and requested the NRCs position regarding related ASR topics. As communicated in the public meeting, the NRC has independently reviewed NextEras prompt operability determinations and concluded the Seabrook ASR-affected structures remain capable of performing their intended safety functions.

While NextEra has developed and implemented research and testing to gain a better understanding of the impact of ASR on reinforced concrete structures similar in design to the Seabrook structures, the NRC has not approved NextEras plans or methods for resolving the ASR issue at Seabrook. We acknowledge that the views of NextEra and C-10 differ, but would not characterize the differences as misstatements as described in your letter. The following provides our responses to the specific issues you raised in your March 10, 2014 letter:

1. NextEras testing plans do not include cancelled Seabrook Unit 2 structure tests.

During the meeting NextEra described their in-progress plans to fabricate and test large scale anchor, shear and rebar anchorage control and ASR affected specimens. NextEras plans do not currently include testing of Seabrook Unit 2. The NRC has neither recommended nor required NextEra to pursue their large scale test program or testing of Seabrook Unit 2. We expect that NextEra will need to clearly establish that the results of their large scale test program are representative of actual conditions at Seabrook. NextEras process for correlating the test program results to Seabrook concrete structures has not been provided to the NRC.

Should NextEra elect to use the results of their large scale test program, or implement another approach to resolve the ASR non-conforming condition, the methodology and results will be subject to NRC review to resolve this non-conforming condition.

2. Why are there not more core tests in Seabrook Unit 1?

Our conclusions regarding NextEras core sampling and testing activities are described in NRC Inspection Reports 05000443/2012009 and 05000443/2012010 (available on the NRCs Seabrook Concrete degradation public webpage). For affected structures, NextEra staff assessed structural design attributes using bounding values for assumed ASR degradation derived from concrete industry test data. These evaluations were informed using the material

S. Gavutis 2 property test results from core samples from various Seabrook ASR-affected and non-affected structures. NRC inspectors reviewed these prompt operability determinations and concluded that there is reasonable assurance, considering the core bore results and bounding structural evaluations, to conclude Seabrook ASR-affected structures remain capable of performing their intended safety functions. As described above, the NRC Staff will evaluate NextEras approach to resolve this non-conforming condition.

3. NextEras characterization of groundwater surrounding the Seabrook Station.

During inspections completed in 2013, NRC inspectors reviewed NextEras structures monitoring program (SMP) with respect to infiltrating groundwater. The inspectors determined that NextEra staff integrated elements of their groundwater monitoring program (in place for other regulatory requirements) into the SMP. The inspectors further determined that NextEra staff had initiated actions to investigate the expansion of their groundwater water monitoring activities to include periodic analysis and trending of infiltrated groundwater to test for aggressive chemistry conditions such as elevated chlorides, sulfates and pH. These inspector observations were documented in Section 7.0 of NRC Inspection Report 2012010 dated August 9, 2013. The NRC similarly described the status of our inspection activities in this regard in a letter to The Union of Concerned Scientists (UCS) dated December 6, 2013. The NRC inspection report and NRCs response letter to UCS are both available on the NRCs Seabrook Concrete degradation public webpage.

The NRC will continue to review and inspect NextEras activities to address the ASR affected structures at Seabrook.

Thank you for your continued interest in the NRCs inspections and oversight of Seabrook Station. Please feel free to contact Mr. Mel Gray at (610) 337-5209 or Mr. William Cook at (610) 337-5074 should you have any further questions or comments to share with us.

Sincerely,

/RA/

Raymond K. Lorson, Director Division of Reactor Safety Docket No. 50-443 License No. NPF-86

ML14112A323 Non-Sensitive Publicly Available SUNSI Review OFFICE RI/DRS/SRA RI/DRS/EB1 RI/DRS NAME WCook/WAC MGray/MG RLorson DATE 04/09/2014 04/09/2014 04/22/2014 S. Gavutis 3 Distribution: via email (EDATS: RegionI-2014-0088)

W. Dean, RA (R1ORAMAIL Resource) G. Dentel, DRP, BC B. Reyes, DRP D. Lew, DRA (R1ORAMAIL Resource) R. Barkley, DRP A. Cass, DRP, AA R. Lorson, DRS (R1DRSMail Resource) M. Draxton, DRP N. McNamara, RI, SLO J. Trapp, DRS (R1DRSMail Resource) P. Cataldo, DRP, SRI D. Tift, RI, SLO M. Scott, DRP (R1DRPMAIL Resource) C. Newport, DRP, RI D. Screnci, RI, PAO E. Benner, DRP (R1DRPMail Resource) M. Gray, DRS, BC N. Sheehan, RI, PAO RidsNrrPMSeabrook Resource A. McMurtray, NRR M. Marshall, NRR RidsNrrDorlLpl1-2 Resource J. Nick, OEDO M. Khanna, NRR RIDSNRRDLR Resource RIDSEDOMailCenter Resource