ML14079A522

Response to Request for Additional Information Regarding License Amendment Request on Revising Section 3.6.5 of the Technical Specifications, Containment Air Temperature

ML14079A522
Person / Time
Site:	Ginna
Issue date:	03/14/2014
From:	Joseph Pacher Constellation Energy Group, EDF Group
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML14079A522 (6)

Text

Joseph E. Pacher Office: 585-771-5200 Site Vice President Fax: 585-771-3943 Email: Joseph.Pacher@cengllc.com

CENGO, a joint venture of O Constellation EnergyeDF e

March 14, 2014 U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 ATTENTION: Document Control Desk

SUBJECT:

R.E. Ginna Nuclear Power Plant Renewed Facility Operating License No. DPR-1 8 Docket No. 50-244 Response to Request for Additional hIformation regarding License Amendment Request on Revising Section 3.6.5 of the Technical Specifications, "Containment Air Temperature"

REFERENCES:

(a) Letter from J.E. Pacher (REG) to NRC Document Control Desk, 'License Amendment Request, Revise Section 3.6.5 of the Technical Specifications, "Containment Air Temperature,"' dated February 28, 2013 (MLI 3067A328)

(b) E-mail from M.C. Thadani (NRC) to T. Harding, Jr. (REG), "FW: Ginna RAI; MF0900," dated February 11, 2014.

By Reference (a), R.E. Ginma Nuclear Power Plant (REG) submitted a License Amendment Request to revise Section 3.6.5 of the Technical Specifications, "Containment Air Temperature," to increase the allowable containment average air temperature from 120OF to 125 0 F.

By Reference (b), the U.S. Nuclear Regulatory Commission (NRC) requested additional inform-ation from REG to complete its review.

The response to Reference (b) is provided in the Attachment.

R.E. Ginna Nuclear Power Plant, LLC 1503 Lake Road, Ontario, New York 14519-9364 oc)(

Document Control Desk March 14,2014 Page 2 Should you have any other questions regarding this submittal, please contact Thomas Harding at 585-77 1-5219.

I declare under penalty of perjury that the foregoing is true and correct. Executed on this 14 day of

_*__-__,-_ 2014.

Sincerely, JEP/JPO

Attachment:

Responses to Questions in Request for Additional Infonrmation (3 Pages) cc: NRC Regional Administrator, Region I NRC Project Manager, Ginna NRC Senior Resident Inspector

ATTACHMENT RESPONSES TO QUESTIONS IN REQUEST FOR ADDITIONAL INFORMATION R.E. Ginna Nuclear Power Plant, LLC March 14, 2014

ATTACHMENT RESPONSES TO QUESTIONS IN REQUEST FOR ADDITIONAL INFORMATION Question #1 Please discuss the impact that the increasedinitial containment temperature may have on the Ginna containment wall temperature. Discuss whether or not the containment wall temperature will surpass it design limit and assess any impact by a change in containment wall temperature on for both LOCA and MSLB analyses results (e.g. Peak Gas Temperature).

Response #1 Large-Break Loss-of-Coolant Accident (LBLOCA)

The containment design temperature limit is 286'F, and the peak temperature during a LBLOCA was determined not to exceed 283.6°F (Reference 1) when considering the increase in initial containment temperature. Therefore, for a LBLOCA the containment wall temperature will remain below the design temperature at all times.

Main Steam-Line Break (MSLB)

For the MSLB analysis, the peak gas temperature does peak above 286°F at approximately 355*F, but the peak only lasts for a few minutes such that the surface temperature of the containment wall will remain below the design temperature. The peak containment air temperature following a steam-line break was previously predicted to be as high as 375*F (Reference 2), which exceeds the currently analyzed peak air temperature. This evaluation, which was performed under the Systematic Evaluation Program and has been accepted by the NRC, determined that these elevated containment air temperatures would not result in a peak liner temperature above the LOCA transient (Reference 2). Therefore, the revised peak gas temperature for the MSLB analysis does not impact the previous evaluation of the containment wall temperature, and the containment wall temperature will remain below the design temperature at all times.

References:

1. Letter from J.E. Pacher (REG) to NRC Document Control Desk, 'License Amendment Request, Revise Section 3.6.5 of the Technical Specifications, "Containment Air Temperature,"' dated February 28, 2013 (ADAMS Accession No. ML13067A328)

2. Letter from J.E. Maier (RG&E) to D.M. Crutchfield (NRC), "SEP Topic 111-7.B, Load Combinations (Containment Liner Analysis)," dated April 28, 1983 (Accession No.

8305060271). Forwards "Containment Vessel Evaluation of Dome Liner & Studs."

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ATTACHMENT RESPONSES TO QUESTIONS IN REQUEST FOR ADDITIONAL INFORMATION Question #2 Please discuss the impact that the increasedinitial containment temperature may have on the Ginna sump water temperature. Please assess any impact on the NPSH availablefor ContainmentSpray and Residual Heat Removal pumps during post-LOCA cooling.

Response #2 Sump water temperature is increased slightly over the previous analysis due to the higher initial containment air temperature. Due to this increase, the NPSH margin for the Residual Heat Removal (RHR) pumps and Containment Spray (CS) pumps were evaluated.

NPSH Margin for RHR Pumps REG, consistent with the guidance of SRP Section 6.2.2, assumes the sump "B" water temperature and the containment atmosphere are saturated for both low-head (RHR) and high-head (Safety Injection) sump recirculation scenarios. This results in the available NPSH being independent of the sump water temperature (Reference la., p. 104). Hence, the small increase in peak recirculation sump water temperature will not impact the NPSH margin currently calculated for low-head and high-head recirculation. High-head recirculation is a piggyback alignment where the RHR pumps take suction from the containment sump and provide water to the suction of the high-head safety injection (SI) pumps. Furthermore, the most limiting conditions relative to RHR Pump NPSH, with and without SI, required during recirculation is conservatively taken as 0 psig Containment pressure and conservatively low Reactor Coolant System (RCS) pressure, which maximizes RHR Pump flow. This limiting condition is unaffected by the change in sump water temperature as the water is assumed saturated.

Ginna does assume a sub-cooled temperature four hours into sump recirculation when high head SI pumps must be re-started following a large break LOCA, i.e., low-head recirculation, to prevent boron precipitation. Normal high-head recirculation alignment requires some elevated RCS pressure; however, this alignment does not credit any RCS pressure, i.e., 0 psig, which results in a slightly elevated RHR flow over the high-head recirculation alignment discussed above. The containment pressure is set to 0 psig. Due to the increase in sump water temperature that resulted from the increase in initial containment air and accumulator temperature the RHR pumps maintain an NPSH margin of greater than 3.50 feet.

NPSH Margin for Containment Spray (CS) Pumps Ginna does not credit Containment Spray pump operation during sump recirculation following a design basis accident. The sump water temperature does not impact the NPSH margin for the Containment Spray pumps.

Therefore, the NPSH margin for the RHR and CS pumps are adequate for the increase in initial containment air temperature.

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ATTACHMENT RESPONSES TO QUESTIONS IN REQUEST FOR ADDITIONAL INFORMATION

References:

1. Letter from P.D. Milano (NRC) to M.G. Korsnick (REG), "R.E. Ginna Nuclear Power Plant -

Amendment Re: 16.8 Percent Power Uprate," dated July 11, 2006 (TAC No. MC7382)

(ADAMS Accession No. ML061380103) la. "Safety Evaluation, Table of Contents" (ADAMS Accession No. ML061380249) 3 of 3