NL-17-0053, Response to Request for Additional Information Regarding SNC License Amendment Request for TSTF-522 Revision 0

Response to Request for Additional Information Regarding SNC License Amendment Request for TSTF-522 Revision 0

ML17013A603
Person / Time
Site:	Vogtle
Issue date:	01/13/2017
From:	Pierce C Southern Nuclear Operating Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NL-17-0053
Download: ML17013A603 (2)

Text

~ Southern Nuclear Charles R. Pierce Regulatory Affairs Director 40 Inverness Center Parkway Post Office Box 1295 Binningham, AL 35242 205 992 7872 tel 205 992 7601 fax JAN 13 2017 crpierce@southernco.com Docket Nos.: 50-424 NL-17-0053 50-425 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Vogtle Electric Generating Plant -Units 1 and 2 Response to Request for Additional Information Regarding SNC License Amendment Request for TSTF-522 Revision 0 Ladies and Gentlemen:

By letter dated November 15, 2016, Southern Nuclear Operating Company (SNC) submitted a license amendment request to adopt TSTF-522, Revision 0, "Revise Ventilation System Surveillance Requirements to Operate for 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> per Month," for the Vogtle Electric Generating Plant (VEGP), Units 1 and 2. The proposed amendment would modify Technical Specification (TS) Surveillance Requirement (SR) 3.7.10.2 such that each control room emergency filtration (CREFS) train would be required to operate for 15 continuous minutes each month instead of 10 continuous hours each month.

Based on follow-up discussion with the Nuclear Regulatory Commission (NRC) staff, it was requested that SNC provide additional detail regarding the SR 3. 7.1 0.2 requirement to have the heater control circuit energized during this surveillance, and to provide detail regarding how the CREFS heaters are tested. This letter documents the discussion during the teleconference.

The CREFS contains heaters that are controlled by the relative humidity of the air flowing through the system. The heaters automatically turn on at a 70% relative humidity to limit the moisture content of the carbon adsorbers. Operation with the heater control circuit energized is verified by a red light at the filter unit. This provides indication the heater control circuit is available to operate if a signal from the moisture transmitter is received. During the surveillance, the red light ensures that the heaters will operate automatically on a high relative humidity signal when required.

The CREFS heater is also tested per the TS 5.5.11 Ventilation Filter Testing Program (VFTP).

Per TS 5.5.11.e, it is required that the heaters for the CREFS dissipate ~ 95 kW when corrected to 460 V when tested in accordance with ASME N510-1989. This VFTP procedure requires the power to the heaters be de-energized so that maintenance can physically inspect the heater elements for loose connections, damaged parts, damaged insulation, and missing parts. Continuity and resistance from phase to ground for each phase on all 3 phases of the heaters is verified. A signal generator is connected to simulate high relative humidity and to cause the SCR master and slave SCR's to turn on the heater (energized). With the heater energized voltage and amp measurements are taken. This data is used to calculate the minimum of 95 KW heat dissipation when the voltage is corrected to 460 V. TS SR 3.7.1 0.3 also requires CREFS filter testing in accordance with the Ventilation Filter Testing Program

U.S. Nuclear Regulatory Commission NL-17-0053 Page2 (VFTP) which includes CREFS heaters. In addition to the electrical test, temperature measurements are taken to ensure temperature rise in the air stream with the heaters energized per ASME N51 0-1989. VEGP operating experience has shown the CREFS heaters to be reliable.

This letter contains no new NRC commitments. If you have any questions, please contact Ken McElroy at 205.992.7369.

Mr. C. R. Pierce states he is Regulatory Affairs Director of Southern Nuclear Operating Company, is authorized to execute this oath on behalf of Southern Nuclear Operating Company and, to the best of his knowledge and belief, the facts set forth in this letter are true.

c.tz.

Respectf'R. ~ubmitted,

~

C. R. Pierce Regulatory Affairs Director ' )

CRP/GKM/GLS My commission expires:

JCl - ({ - ;liJ I I cc: Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. D. G. Bost, Executive Vice President & Chief Nuclear Officer Mr. D. R. Madison, Vice President- Fleet Operations Mr. M. D. Meier, Vice President- Regulatory Affairs Mr. B. K. Taber, Vice President- Vogtle 1 & 2 Mr. B. J. Adams, Vice President- Engineering Mr. D. D. Sutton, Regulatory Affairs Manager- Vogtle 1 & 2 RType: CVC7000 U. S. Nuclear Regulatorv Commission Ms. C. Haney, Regional Administrator Mr. M. D. Orenak, NRR Senior Project Manager- Vogtle 1 & 2 Mr. M. F. Endress, Senior Resident Inspector- Vogtle 1 & 2 State of Georgia Mr. R. E. Dunn, Director- Environmental Protection Division