ML15050A096

E-mail Re. Request for Additional Information Related to LAR to Ice Condendser Inc Mass Tech Spec

ML15050A096
Person / Time
Site:	Sequoyah
Issue date:	02/19/2015
From:	Andrew Hon Plant Licensing Branch II
To:	James Shea Tennessee Valley Authority
Hon A
References
Download: ML15050A096 (3)

Text

From: Hon, Andrew Sent: Thursday, February 19, 2015 11:21 AM To: Shea, Joseph W Owshea@tva.gov)

Cc: Sallman, Ahsan; Helton, Shana; Hess, Thomas A (tahess@tva.gov)

Subject:

SEQUOYAH NUCLEAR STATION, UNIT 1- REQUEST FOR ADDITIONAL INFORMATION RELATED TOLAR to Ice Condendser Inc Mass Tech Spec.

ADAMSAccessionNumber: ML15050A096 Mr. Joseph W. Shea Vice President, Nuclear Licensing Tennessee Valley Authority 6A Lookout Place 11 01 Market Street Chattanooga, TN 37402-2801

SUBJECT:

SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2,- REQUEST FOR ADDITIONAL INFORMATION RELATED TO LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATION ON ICE CONDENSER ICE MASS (TAC NOS. MF2446 AND MF2447)

Dear Mr. Shea:

In a letter dated July 3, 2013, (Agencywide Documents Access and Management System (ADAMS) Accession Nos. ML13199A281) (Reference 1), Tennessee Valley Authority (TVA or the licensee) requested an amendment to Operating Licenses (OLs) DPR-77 and DPR-79 for the Sequoyah Nuclear Plant (SQN), Units 1 and 2, respectively, in the form of changes to the Technical Specifications (TSs). TVA supplemented Reference 1 by letter dated February 13, 2014 (Reference 2).

The U.S. Nuclear Regulatory Commission (NRC) staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed below. The proposed questions were discussed by telephone with your staff on February 18, 2015. Your staff confirmed that these questions did not include proprietary or security-related information and agreed to provide a response by March 31, 2015 to this request for additional information (RAI).

1

The NRC staff considers that timely responses to RAls help ensure sufficient time is available for staff review and contribute toward the NRC's goal of efficient and effective use of staff resources. Please note that if you do not respond to this request by the agreed-upon date or provide an acceptable alternate date, we may deny your application for amendment under the provisions of Title 10 of the Code of Federal Regulations, Section 2.108. If circumstances result in the need to revise the agreed upon response date, please contact me at (301) 415-8480 or via e-mail Andrew.Hon@nrc.gov.

Sincerely, RIA Andrew Hon, Project Manager Plant Licensing Branch 11-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328 Accession No. ML15050A096 2

REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST TO CHANGE TO TECHNICAL SPECIFICATION TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (WBN), UNIT 1 AND UNIT 2 DOCKET NOS. 50-327 AND 50-328 SCVB-RAl-9 In UFSAR Section 6.2.1.3.4, under heading "Containment Pressure Calculation", the ice temperature used in the containment pressure calculation as per assumption (10) is 15°F. On the other hand, Surveillance Requirement (SR) 4.6.5.1a states:

"At least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> by verifying that the maximum ice bed temperature is less than or equal to 27°F."

The ice bed temperature is a key parameter for the ice condenser performance for pressure suppression, i.e.,

assuming a lower ice bed temperature for the long term pressure response is less conservative than using a higher temperature. For a conservative containment pressure calculation, please justify using a non-conservative assumption of ice temperature of 15°F instead of 27°F.

SCVB-RAl-10 In UFSAR Section 6.2.1.3.4, under heading "Containment Pressure Calculation", the input assumption (10) for containment pressure calculation states the initial containment air temperature of 100°F in the lower volume and dead-ended volumes, and 85°F in the upper volume. On the other hand, TS 3.6.1.5 states that the maximum values of 105°F in the upper volume and 125°F in the lower volume shall be maintained.

By sensitivity analyses, please justify these temperatures in the UFSAR would maximize the peak containment transient pressure compared to the transient pressure obtained by using the initial TS maximum values.

REFERENCES

1. Letter from TVA to NRC dated July 3, 2013, "Application to Modify Ice Condenser Technical Specifications to Address Revisions in Westinghouse Mass and Energy Release Calculation (SQN-TS-12-04)", (ADAMS Accession Number ML13199A281)

2. Letter from TVA to NRC dated February 13, 2014, "Response to NRC Request for Additional Information Regarding Sequoyah Nuclear Plant (SQN), Units 1 and 2 -Application to Modify Ice Condenser Technical Specifications to Address Revisions in Westinghouse Mass and Energy Release Calculation (SQN-TS-12-04)(TAC Nos. MF2446 and MF2447)", (ADAMS Accession Number ML14045A290) 3