ML13353A296

Response to Request for Additional Information Regarding License Amendment Request to Revise Technical Specification 6.8.4.F for Peak Calculated Containment Internal Pressure

ML13353A296
Person / Time
Site:	Millstone
Issue date:	12/11/2013
From:	Mark D. Sartain Dominion Nuclear Connecticut
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
13-621
Download: ML13353A296 (6)

Text

Dominion Nuclear Connecticut, Inc.

5000 Dominion Boulevard, Glen Allen, VA 23060 Domiion Web Address: www.dom.com December 11, 2013 U.S. Nuclear Regulatory Commission Serial No.13-621 Attention: Document Control Desk NSSL/MLC RO Washington, DC 20555 Docket No. 50-423 License No. NPF-49 DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 3 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATION 6.8.4.F FOR PEAK CALCULATED CONTAINMENT INTERNAL PRESSURE By letter dated April 25, 2013, Dominion Nuclear Connecticut, Inc. (DNC) submitted a license amendment request (LAR) for Millstone Power Station Unit 3 (MPS3). The proposed amendment would revise the peak calculated containment internal pressure for the design basis loss of coolant accident described in Technical Specification (TS) 6.8.4.f, "Containment Leakage Rate Testing Program." The peak calculated containment internal pressure, Pa, would increase from 41.4 psig to 41.9 psig. In a letter dated August 8, 2013, the Nuclear Regulatory Commission (NRC) transmitted a request for additional information (RAI) to DNC related to the LAR. DNC responded to the RAI in a letter dated September 19, 2013. In a letter dated November 6, 2013, the NRC transmitted another RAI. DNC agreed to respond to the RAI by December 23, 2013.

The attachment to this letter provides DNC's response to the NRC's RAI.

If you have any questions regarding this submittal, please contact Wanda Craft at (804) 273-4687.

Sincerely, VICKI L. HULL Mark D. Sartain Notary Public Vice President - Nuclear Engineering and Development Commonwealth of Virginia 140542 COMMONWEALTH OF VIRGINIA ) My Commission Expires May 31, 2014 COUNTY OF HENRICO The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Mark D. Sartain, who is Vice President - Nuclear Engineering and Development of Dominion Nuclear Connecticut, Inc.

He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that Company, and that the statements in the document are true to the best of his knowledge and belief.

Acknowledged before me this ___.day of L)C(A,7 ,t, 2013.

My Commission Expires: -1&1,4 31 -,04 .

Notary Public Lu,17-L

Serial No.13-621 Docket No. 50-423 Page 2 of 2 Commitments made in this letter: None

Attachment:

Response to Request for Additional Information Regarding License Amendment Request to Revise Technical Specification 6.8.4.f for Peak Calculated Containment Internal Pressure cc: U.S. Nuclear Regulatory Commission Region I 2100 Renaissance Blvd, Suite 100 King of Prussia, PA 19406-2713 J. S. Kim Project Manager U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 08-C2A 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station Director, Radiation Division Department of Energy and Environmental Protection 79 Elm Street Hartford, CT 06106-5127

Serial No.13-621 Docket No. 50-423 ATTACHMENT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO REVISE TECHNICAL SPECIFICATION 6.8.4.F FOR PEAK CALCULATED CONTAINMENT INTERNAL PRESSURE DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 3

Serial No.13-621 Docket No. 50-423 Attachment 1, Page 1 of 3 By letter dated April 25, 2013, Dominion Nuclear Connecticut, Inc. (DNC) submitted a license amendment request (LAR) for Millstone Power Station Unit 3 (MPS3). The proposed amendment would revise the peak calculated containment internal pressure for the design basis loss of coolant accident (LOCA) described in Technical Specification (TS) 6.8.4.f, "Containment Leakage Rate Testing Program." The peak calculated containment internal pressure, Pa, would increase from 41.4 psig to 41.9 psig. In a letter dated August 8, 2013, the Nuclear Regulatory Commission (NRC) transmitted a request for additional information (RAI) to DNC related to the LAR. DNC responded to the RAI in a letter dated September 19, 2013. In a letter dated November 6, 2013, the NRC transmitted another RAI. This attachment provides DNC's response to the NRC's RAI.

Question EEEB-1 In the LAR, the licensee states the following:

Change in Pa does not affect environmentally qualified equipment.

The containment temperatures,using the correctedlarge break LOCA mass and energy (M&E) releases, remain within the bounding containment temperature profile used to qualify equipment.

a. Provide a discussion of the Environmental Qualification (EQ) re-analysis performed to show that the equipment remained qualified. In addition,provide a comparison of the EQ overlays with containment temperature and pressureprofiles.

b. Explain how margins are being maintained for qualified equipment in accordance with 10 CFR 50.49.

DNC Response

a. The EQ bounding temperature profile taken from the MPS3 Environmental Specification (SP-M3-EE-0333) is used for the environmental qualification of plant equipment. The most limiting LOCA for peak containment pressure and temperature is a double-ended guillotine break of the hot leg. The containment peak pressure for this break has resulted in the current request to increase Pa. Figure 1 shows that the EQ bounding temperature profile envelopes the containment temperature profile from the double-ended hot leg break analysis. Therefore, there is no impact on the existing MPS3 EQ program, and the EQ program remains in compliance with 10 CFR 50.49.

Similarly, the EQ bounding pressure profile taken from the MPS3 Environmental Specification (SP-M3-EE-0333) is used for the environmental qualification of plant equipment. Figure 2 shows that the EQ bounding pressure profile envelopes the

Serial No.13-621 Docket No. 50-423 Attachment 1, Page 2 of 3 containment pressure profile from the double-ended hot leg break analysis.

Therefore, there is no impact on the existing MPS3 EIQ program, and the EQ program remains in compliance with 10 CFR 50.49.

b. Temperature and pressure margins in the MPS3 EQ program are applied in accordance with 10 CFR 50.49 and Regulatory Guide 1.89. These margins are applied in addition to the EQ bounding (SP-M3-EE-0333) temperature and pressure profiles for equipment qualified to 10 CFR 50.49. This combination of EQ bounding profiles plus temperature and pressure margins is considered bounded by the MPS3 equipment test profiles, which are tested to harsher environmental conditions.

Therefore, there is no impact on the existing MPS3 EQ program.

Figure 1 400 350 33500 00 il....

.. -1...

250 i............................. -. 4 ------

I.J-i .4 i 4.

/

m _*^ i 20.

I*

.... Double Ended Hot Leg Break E N* N.

2150 ..

-EQ Temperature 100 Envelope 50 4.

.1.........................

I.............

1 10 100 1000 10000 100000 Time, Seconds

Serial No.13-621 Docket No. 50-423 Attachment 1, Page 3 of 3 Figure 2 70

'I 60 I

I J#

50 ...

-~i 1

Lf~

40 I 0~ 40 / ...- Double C-. Ended Hot I

IA I Leg Break I  %............................

30 t 1

'I EEQ I Pressure 20 '/ Envelope 10 .....................................

0 "i...........................................

I 10 100 1000 10000 100000 Time, Seconds Question EEEB-2 Provide a discussion on any impact of the proposed change on areas of the plant outside of containment (e.g., changes to EQ parameters such as temperature and pressure).

DNC Response The proposed change in calculated peak containment internal pressure for the design basis loss of coolant accident does not result in any impact on any area of the plant outside containment. As a result, environmental conditions outside containment remain bounded by existing site calculations.