ML14176A129

Clarification to April 7, 2014 Supplement to Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)

ML14176A129
Person / Time
Site:	Ginna
Issue date:	05/16/2014
From:	Korsnick M Constellation Energy Nuclear Group, Exelon Generation Co, Ginna
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-12-049
Download: ML14176A129 (5)

Text

G n a i Exe!.on Maria Korsnick l O Exelon Generation, Senior Vice President, Northeast Operations Chief Nuclear Officer, CENG 100 Constellation Way Suite 200C, Constellation Energy Nuclear Group, LLC Baltimore, MD 21202 410-470-5133 Office 443-213-6739 Fax www.exeloncorp.com maria.korsnick@exeloncorp.com May 16, 2014 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852 R.E. Ginna Nuclear Power Plant Renewed Facility Operating License No. DPR-18 Docket No. 50-244

Subject:

Clarification to April 7, 2014 Supplement to Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049)

References:

(1) Letter from M. Korsnick (CENG) to NRC Document Control Desk, Supplement to Response to March 12, 2012, Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design Basis External Events, dated April 7, 2014 (Order Number EA-12-049)

(2) Letter from J. S. Bowen (NRC) to M. G. Korsnick (CENG), R. E. Ginna Nuclear Power Plant - Interim Staff Evaluation Relating to Overall Integrated Plan in Response to Order EA-12-049 (Mitigating Strategies)

(TAC NO. MF1152), dated February 19, 2014 (ML14007A704)

On April 7, 2014, Constellation Energy Nuclear Group, LLC (CENG) submitted a supplement (Reference 1) to the response to the.March 12, 2012 Commission Order modifying licenses with regard to requirements for mitigation strategies for beyond design-basis external events. Reference 1 clarified and amplified several statements in the Overall Integrated Plan (OIP) which were reflected in the NRC Interim Safety Evaluation (ISE) issued to CENG (Reference 2). R. E. Ginna Nuclear Power Plant, LLC (Ginna) is providing this letter to clarify statements made in the Attachment to Reference (1).

In the first bullet of item 1 of the Attachment to Reference (1), CENG stated that "Robust structures housing the "N" set of FLEX mitigation equipment, as well as communications equipment, will be designed / evaluated to withstand the Regulatory Guide 1.76, [Rev. 1]

tornado wind speed and suite of tornado missiles."

U. S. Nuclear Regulatory Commission May 16, 2014 Page 2 For conservatism, Ginna designed the structural walls and roof of the new "robust structure" to the Regulatory Guide 1.76, Rev. 1 tornado wind speed and suite of tornado missiles. However, the building's entranceway and openings (e.g., as needed for ventilation) are designed to withstand the plant's design basis tornado (i.e., 132 miles per hour wind speed) and tornado missile spectrum. This is consistent with NEI 12-06, Section 7.3.1.1.a.

Furthermore, the "+1" equipment (high and low pressure FLEX pumps, hoses and fittings; and 100 kilowatt generator, cables and connectors) and support equipment (fuel trailer, debris remover, and tow truck) will generally be housed in a New York State (NYS)

Building Code commercial structure, an "evaluated storage location" per NEI 12-06, Section 7.3.1.1.c. Distance separation is not applicable in this situation, since the means used to minimize the probability that a single event would damage all FLEX mitigation equipment is the use of a robust structure to house the N sets. Any stored mitigation equipment exposed to the wind will be adequately tied down to prevent it from being damaged or becoming airborne, in accordance with NEI 12-06, Section 7.3.1.1.b.

The above design criteria are consistent with the Ginna's current design basis, and therefore meets the requirements of NEI 12-06, Section 7.3.1.1.

Based on the above, Ginna will revise the Mitigating Strategies OIP to reflect the above FLEX equipment storage design criteria, and will design tornado protection based on these design criteria. This change to the Ginna Mitigating Strategy OIP will be incorporated in the next 6-month update report.

In Item 2 of the Attachment to Reference (1), Ginna requested that the NRC staff evaluate the approach of using the decay heat models in current licensing basis / engineering calculations, used to support mitigation strategies at Ginna, as being consistent with the guidance found in NEI 12-06. To support that request an example of a decay heat model used in a current licensing basis / engineering calculation is provided.

Calculation 109682-M-026, "Steam Generator Dry-Out Time Assuming No Feedwater Addition under EPU," uses the decay heat model taken from Branch Technical Position ASB 9-2, "Residual Decay Energy for Light Water Reactors for Long Term Cooling," which is contained in NUREG-75/087, "Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition," Revision 1. For additional conservatism the reactor was assumed to be operating at 102% rated thermal power, which is above the 100% rated thermal power criteria stated in NEI 12-06, Section 3.2.1.2.

Attachment (1) lists the regulatory commitments contained within this correspondence.

If there are any questions regarding this submittal, please contact Bruce Montgomery, Acting Manager - Licensing, at 443-532-6533.

U. S. Nuclear Regulatory Commission May 16, 2014 Page 3 I declare under penalty of perjury that the foregoing is true and correct. This statement executed on the 16th day of May, 2014.

Sin cerely SincerelvC Mary G. Korsnick Chief Nuclear Officer Constellation Energy Nuclear Group, LLC MGK/GW/STD Attachment (1) - Regulatory Commitments Contained Within this Correspondence cc: Regional Administrator, Region I, USNRC Resident Inspector, USNRC Project Manager, USNRC S. Gray, DNR J. Boska, PM Mitigation Strategies, NRR/MSD

ATTACHMENT (1)

REGULATORY COMMITMENTS CONTAINED IN THIS CORRESPONDENCE R. E. Ginna Nuclear Power Plant, LLC May 16,2014

ATTACHMENT (1)

REGULATORY COMMITMENTS CONTAINED IN THIS CORRESPONDENCE The following table defines the R. E. Ginna Nuclear Power Plant, LLC (Ginna) regulatory commitments contained in this correspondence.

DESCRIPTION DUE DATE

1. Ginna will revise the Mitigating Strategies Overall Integrated Plan August 28, 2014 (OIP) to reflect the FLEX equipment storage design criteria regarding the protection of FLEX equipment for high wind hazards in accordance with Section 7.3.1.1 of NEI 12-06, and will design tornado protection based on these design criteria. This change to the Ginna Mitigating Strategy OIP will be incorporated in the next 6-month update report.

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