NExTera

ENERG-_7Y1

November 21, 2014

10 CFR 50.54

SBK-L-14196

Docket No. 50-443

U. S. Nuclear Regulatory Commission

Attn: Document Control Desk

Washington, DC 20555-0001

Seabrook Station

Revised Response to Follow up RAI B.2.1.31A-3 provided in SBK-L- 14086

Relating to the Alkali-Silica Reaction (ASR) Monitoring Program

References:

1. NextEra Energy Seabrook, LLC letter SBK-L- 10077, "Seabrook Station Application for

Renewed Operating License," May 25, 2010. (Accession Number ML101590099)

2. NRC Letter, Requests For Additional Information for the Review of the Seabrook Station,

License Renewal Application- Set 20 (TAC NO. ME4028), January 15, 2014, (Accession

Number ML 13357A628)

3. NextEra Energy Seabrook, LLC letter SBK-L-14086, "Requests for Additional Information

for the Review of the Seabrook Station, License Renewal Application- SET 20 (TAC NO.

ME4028) Relating to the Alkali-Silica Reaction (ASR) Monitoring Program," May 15, 2014

(Accession Number ML 14142A220).

In Reference 1, NextEra Energy Seabrook, LLC (NextEra) submitted an application for a

renewed facility operating license for Seabrook Station Unit 1 in accordance with the Code of

Federal Regulations, Title 10, Parts 50, 51, and 54.

In Reference 3, NextEra provided a response to NRC staff RAI B.2.1.31 A-3 related to Tier 2

qualitative and quantitative monitoring criteria. Based on a subsequent teleconference with the

staff on September 30, 2014, NextEra is providing additional clarifying detail. Enclosure 1

contains NextEra Seabrook revised response to RAI B.2.1.3 1A-3 previously provided in

Reference 3.

NextEra Energy Seabrook, LLC, P.O. Box 300, Lafayette Road, Seabrook, NH 03874
U.S. Nuclear Regulatory Commission

SBK-L-14196 / Page 2

This letter contains no revised or new commitments.

If there are any questions or additional information is needed, please contact Mr. Edward J.

Carley, Engineering Supervisor - License Renewal, at (603) 773-7957.

If you have any questions regarding this correspondence, please contact Mr. Michael Ossing

Licensing Manager, at (603) 773-7512.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on November W1, 2014.

bean Curtland

Site Vice President

NextEra Energy Seabrook, LLC

Enclosures:

Enclosure 1- Revised Response to Follow up RAI B.2.1.31A-3 provided in SBK-L-14086

Relating to the Alkali-Silica Reaction (ASR) Monitoring Program

cc: W. M. Dean NRC Region I Administrator

J. G. Lamb NRC Project Manager

P. C. Cataldo NRC Senior Resident Inspector

R. A. Plasse NRC Project Manager, License Renewal

L. M. James NRC Project Manager, License Renewal

Mr. Perry Plummer

Director Homeland Security and Emergency Management

New Hampshire Department of Safety

Division of Homeland Security and Emergency Management

Bureau of Emergency Management

33 Hazen Drive

Concord, NH 03305

Mr. John Giarrusso, Jr., Nuclear Preparedness Manager

The Commonwealth of Massachusetts

Emergency Management Agency

400 Worcester Road

Framingham, MA 01702-5399
Enclosure 1 to SBK-L-14196

Revised Response to Follow up RAI B.2.1.31A-3 provided in SBK-L-14086

Relating to the Alkali-Silica Reaction (ASR) Monitoring Program
U.S. Nuclear Regulatory Commission

SBK-L-14196 / Enclosure 1 / Page 2 of 4

RAI B.2.1.31A-3

Background:

The "acceptance criteria" program element of the applicant's ASR Monitoring Program states

that the program will use the thresholds stated in its report MPR-3727, Revision 0, "Seabrook

Station: Impact of ASR on Concrete Structures and Attachments" as the acceptance criteria for

evaluating ASR-affected structures. The acceptance criteria stated in that report is also described

in the ASR Monitoring Program description. The acceptance criteria chart in the AMP program

description indicates that there are two sub-categories of Tier 2 locations, one requiring

"quantitative monitoring and trending", one requiring only "qualitative monitoring".

Issue:

The staff noted that the applicant has performed a baseline inspection and that structural

evaluations were performed for locations exceeding the Tier 3 criteria, which require structural

evaluations. For the remaining areas, the staff noted that those locations exceeding the Tier 2

criteria for monitoring and trending will be inspected using crack indexing measurements and

trended to monitor the progression of ASR. However, it is not clear how new locations will be

identified for crack indexing at the Tier 2 frequency. If some of the Tier 2 locations are

"qualitatively monitored", (i.e., visual examination with no crack indexing), the staff is unclear

as to how the program will identify when new locations meet the threshold for quantitative

monitoring.

Request:

If crack indexing will only be used for locations that exceed a CCI of .5 mm/m or individual

crack width of .2 mm (Tier 2 criteria), state how the program will identify when a location is

required to change from "qualitative monitoring" to "quantitative monitoring and trending".

Revised NextEra Energy Seabrook Response to RAI B.2.1.31A-3

Per the Structural Monitoring Program, B.2.1.31, which has been augmented by the plant

specific Alkali-Silica Reaction Monitoring Program, B.2.1.3 1A, visual inspections are initially

performed and subsequent crack width measurements are taken if the area exceeds Tier 1

criteria. In regards to monitoring ASR related degradation, if there is no visual presence of ASR

(ASR visual characteristics as defined in the U.S. Department of Transportation Federal

Highway Administration's publication FHWA-HIF- 12-022 "Alkali-Silica Reactivity Field

Identification Handbook"), the location is considered Tier 1 and no further evaluation is

performed. Tier 1 locations are deemed "Acceptable" and are monitored on a frequency set

forth by the Structural Monitoring Program.
U.S. Nuclear Regulatory Commission

SBK-L-14196 / Enclosure 1 / Page 3 of 4

Areas with visual presence of ASR are observed and individual crack widths are measured using

a Pocket-size Crack Comparator Card and/or an Optical Comparator with a magnifying power of

7X or more.

The change from Tier 2 qualitative monitoring to quantitative monitoring occurs when an area

exhibits visual presence of ASR and is accompanied by either individual crack widths equal to or

greater than 0.20 mm or the estimated summation, excluding craze cracking (fine random cracks

or fissures in the surface of the concrete; i.e. cracks less than 0.05 mm), of individual crack

widths in an area that could support a cracking index (CI) of equal to or greater than 0.50 mni/m

in either the vertical or horizontal direction. If either of these two criteria are observed along

with the visual presence of ASR, an indexing grid is laid out and a combined cracking index

(CCI) is calculated. All Tier 2 locations will be subject to re-inspection on a 2.5 year frequency.

Based on the above discussion, a new paragraph has been added to the end of the program

description of the Alkali-Silica Reaction Monitoring Program, B-2.1.31 A, and the table provided

in the program description of the Alkali-Silica Reaction Monitoring Program, B.2.1.3 1A has

been modified for clarification purposes, as follows:

Recommendation for

Tier Structural Monitoring Individual Concrete Combined Cracking Individual Crack

Program Category Components Index (CCI) Width

3 Unacceptable (requires Structural Evaluation 1.0 mm/m or greater 1.0 mm or greater

further evaluation)

Quantitative Monitoring and antoing a 0.5 mm/m or greater 0.2 mm or greater Trending

Any area with visual presence of ASR (as

2 Acceptable with defined in FHWA-HIF-12-022) DeficienciesQualitative Monitoring accompanied by individual crack widths less

than 0.2 mm and an estimated summation of

crack widths not supporting a 0.5 mm/m CI

in the vertical or horizontal direction.

Routine inspection as Area has no indications of pattern cracking

I Acceptable prescribed by the Structural

Monitoring Program or water ingress- No visual presence of ASR

Visual inspections are initially performed and subsequent crack width measurements are taken if

the area exceeds Tier 1 criteria. In regards to monitoring ASR related degradation, if there is no

visual presence of ASR (ASR visual characteristics as defined in FHWA-HIF-12-022 "AlkaliSilica Reactivity Field Identification Handbook"), the location is considered Tier 1 and no

further evaluation is performed. Tier 1 locations are deemed "Acceptable" and are monitored on

a frequency set forth by the Structural Monitoring Program.
1U.S. Nuclear Regulatory Commission

SBK-L-14196 / Enclosure 1 / Page 4 of 4

Areas with visual presence of ASR are observed and individual crack widths are measured using

a Pocket-size Crack Comparator Card and/or an Optical Comparator with a magnifying power of

7X or more.

The change from Tier 2 qualitative monitoring to quantitative monitoring occurs when an area

exhibits visual presence of ASR and is accompanied by either individual crack widths equal to or

greater than 0.20 mm or the estimated summation, excluding craze cracking (fine random cracks

or fissures in the surface of the concrete; i.e. cracks less than 0.05 mm), of individual crack

widths in an area that could support a cracking index (CI) of equal to or greater than 0.50 mm/m

in either the vertical or horizontal direction. If either of these two criteria are observed along

with the visual presence of ASR, an indexing grid is laid out and a combined cracking index

(CCI) is calculated. All Tier 2 locations will be subject to re-inspection on a 2.5 year frequency.