Mark T. Finley 750 East Pratt Street, Suite 1400Baltimore, Maryland 21202

Senior Vice President, Regulatory Affairs & Engineering

UJniotar 10 CFR 50.4

NUCLEAR ENERGY 10 CFR 52.79

June 21, 2013

UN#1 3-080

ATTN: Document Control DeskU.S. Nuclear Regulatory CommissionWashington, DC 20555-0001

Subject: UniStar Nuclear Energy, NRC Docket No. 52-016Response to Request for Additional Information for theCalvert Cliffs Nuclear Power Plant, Unit 3,RAI 390, Stability of Subsurface Materials and Foundations

References: 1) Surinder Arora (NRC) to Paul Infanger (UniStar Nuclear Energy), "CCNPP3- FINAL RAI 390 RGS2 7074," email dated April 25, 2013

2) UniStar Nuclear Energy Letter UN#13-071, from Mark T. Finley toDocument Control Desk, U.S. NRC, Response to Request for AdditionalInformation for the Calvert Cliffs Nuclear Power Plant, Unit 3, RAI 390,Stability of Subsurface Materials and Foundations, dated May 21, 2013

The purpose of this letter is to respond to the request for additional information (RAI) identifiedin the NRC e-mail correspondence to UniStar Nuclear Energy, dated April 25, 2013(Reference). This RAI addresses Stability of Subsurface Materials and Foundations, asdiscussed in Section 2.5.4 of the Final Safety Analysis Report (FSAR), as submitted in Part 2 ofthe Calvert Cliffs Nuclear Power Plant (CCNPP) Unit 3 Combined License Application (COLA),Revision 9.

Reference 2 indicated that a response to RAI 390, Question 02.05.04-32, would be provided tothe NRC by June 21, 2013.

Enclosure 1 provides our response to RAI No. 390, Question 02.05.04-32, and includes revisedCOLA content. A Licensing Basis Document Change Request has been initiated to incorporatethese changes into a future revision of the COLA.

Enclosure 2 provides a table of changes to the CCNPP Unit 3 COLA associated with thisRAI 390 response.

UN#1 3-080Page 2

Our response does not include any new regulatory commitments. This letter, and itsenclosures, does not contain any sensitive or proprietary information.

If there are any questions regarding this transmittal, please contact me at (410) 369-1907 or

Mr. Wayne A. Massie at (410) 369-1910.

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

Enclosures: 1) Response to NRC Request for Additional Information RAI No. 390, Question02.05.04-32, Stability of Subsurface Materials and Foundations, CalvertCliffs Nuclear Power Plant, Unit 3

2) Table of Changes to CCNPP Unit 3 COLA Associated with Response to RAINo. 390

cc: Surinder Arora, NRC Project Manager, U.S. EPR Projects BranchLaura Quinn-Willingham, NRC Environmental Project Manager, U.S. EPR COL ApplicationAmy Snyder, NRC Project Manager, U.S. EPR DC Application, (w/o enclosures)Patricia Holahan, Acting Deputy Regional Administrator, NRC Region II, (w/o enclosures)Silas Kennedy, U.S. NRC Resident Inspector, CCNPP, Units 1 and 2,David Lew, Deputy Regional Administrator, NRC Region I (w/o enclosures)

UN#13-080

Enclosure 1

Response to NRC Request for Additional InformationRAI No. 390, Question 02.05.04-32,

Stability of Subsurface Materials and Foundations,Calvert Cliffs Nuclear Power Plant, Unit 3

Enclosure 1UN#1 3-080Page 2 of 4RAI No. 390

Question 02.05.04-32

This Question is a follow up of Question 02.05.04-31 (RAI 307, eRAI 5741)

Although the applicant responded to several RAIs regarding the settlement evaluation for theCCNPP Unit 3 site, actual settlement at this site still remains an unresolved concern. Settlementis an important stability issue at a deep soil site and large foundation settlement is expected forthe CCNPP Unit 3 site. Additionally, with many uncertainties and variations related to theproperties of subsurface materials and the models used in settlement analysis, different modelsprovided a wide range of settlement estimates and there is no model that can exactly predictwhat will actually occur in the field. To confirm that the actual settlements of the safety relatedstructures during and after construction meet the design requirements, in accordance with 10CFR 100.23, please provide specific inspection, testing analysis and acceptance criteria onsettlement control.

Response

An Inspections, Tests, Analyses, and Acceptance Criteria (ITAAC) for settlement has beenincorporated into Part 10 of the CCNPP Unit 3 COLA as indicated in new ITAAC Table 2.4-36.

In case the acceptance criteria values are challenged, measures will be taken to control thedifferential settlements, such as extending the duration of dewatering, delaying connections,and rearranging backfill.

There are no combined license (COL) items in the US EPR Design Certification that limit theamount of total settlement. However, impact control measures to control the possible largesettlements include delaying the connections between the building(s), adjusting the plant grade,reassessing surface drainage features, and delaying connections to pipelines that connect thePowerblock with external facilities. Total settlement is continuously monitored duringconstruction in order to promptly implement settlement control measures.

COLA Impact

CCNPP Unit 3 COLA Part 10, ITAAC, Section 2.4, has been revised as follows:

2.4 Site-Specific ITAAC

The Site-Specific ITAAC are provided in {Table 2.4-1 through Table 2.4-3__6}. Site-specificsystems were evaluated against selection criteria in {CCNPP Unit 3} FSAR Section 14.3.

Enclosure 1UN#13-080Page 3 of 4

A new Settlement Control Table 2.4-36 has been added to the CCNPP Unit 3 COLA Part 10,

ITAAC, as follows:

Table 2.4-36 - (Settlement Control InsDections. Tests. Analyses, and Acceptance Criterial

1 Settlement of NuclearIsland (NI) structuresmeasured 3 months prior tofuel load shall besatisfactory by meeting thevalues in the acceptancecriteria.

Field measurements ofsettlements of the NI commonbasemat will be taken 3 monthsprior to fuel load.

Settlement of NI structures issatisfactory by either:

* Measured tilt 1 being lessthan 1/2" in 50 ft (1/1200)and

* Angular distortion of thebasemat, using methodsdescribed in U.S. ArmyEngineering Manual 1110-1-1904, being less thanthe U.S. EPR FSARFigure 3.8-134

or" Performing an analysis to

demonstrate that thestructural design isadequate based on thefield measurements.

-I-2 Settlement of Emerqency

Power Generatina BuildinaField measurements ofsettlements of the EPGB will betaken 3 months prior to fuel load.(EPGB) structures

measured 3 months prior tofuel load shall besatisfactory by meeting thevalues in the acceptancecriteria.

Settlement of EPGB structures issatisfactory by either:

* Measured tilt 1 being lessthan 1/2" in 50 ft (1/1200)and

" Angular distortion of thebasemat, using methodsdescribed in U.S. ArmyEngineering Manual 1110-1-1904, being less thanthe U.S. EPR FSARFigure 3.8-135

or* Performing an analysis to

demonstrate that thestructural design isadequate based on thefield measurements.

3 Settlement of Essential Field measurements of Settlement of ESWB structures isService Water Building settlements of ESWB will be satisfactory by either:(ESWB) structures taken 3 months prior to fuel load. 0 Measured tilt1 being lessmeasured 3 months prior to than 3/4" in 50 ft (1/800)fuel load shall be andsatisfactory by meeting the 0 Angular distortion of thevalues in the acceptance basemat, using methodscriteria. described in U.S. Army

Engineering Manual 1110-1-1904, being less than

Enclosure 1UN#13-080Page 4 of 4

Table 2.4-36 - (Settlement Control Inspections, Tests, Analyses, and Acceptance Criteria)

the U.S. EPR FSARFigure 3.8-136

or* Performing an analysis to

demonstrate that thestructural design isadequate based on thefield measurements.

4 Settlement of Common Field measurements of Settlement of CBIS structures isBasemat Intake Structures settlements of the CBIS will be satisfactory by either:(CBIS) structures taken 3 months prior to fuel load. 0 Measured tilt' being lessmeasured 3 months prior to than 1/2" in 50 ft (1/1200)fuel load shall be orsatisfactory by meeting the * Performing an analysis tovalues in the acceptance demonstrate that thecriteria. structural design is

adequate based on thefield measurements.

NOTE:' Tilt is the difference in settlement measured in the East-West and North-South (building coordinates)directions from edge to edqe of the foundation footprint.

UN#13-080

Enclosure 2

Table of Changes to CCNPP Unit 3 COLA Associated with Response to RAI No. 390

Enclosure 2UN#1 3-080Page 2 of 2

Table of Changes to CCNPP Unit 3 COLA Associated with Response to RAI No. 390

Change Subsection Type of Change Description of ChangeID # 1Part 10- Inspections, Tests, Analyses, and Acceptance Criteria (ITAAC) and ITAACClosureCC3-13- Appendix B, Incorporate COLA markups The RAI No. 390, Question 02.05.04-0098 Section 2.4 associated with the response 32 response (this response) involved

and new to RAI No. 390, Question the addition of new Settlement ControlTable 2.4-36 02.05.04-32 (this response). ITAAC Table 2.4-36.