CY-98-127, Provides Clarifying Info Re Spent Fuel Pool make-up Capability at Hnp.Conclusions Reached by NRC Staff in SER Contained in Issuance of License Amend 193 Not Impacted & & Remain Valid

Provides Clarifying Info Re Spent Fuel Pool make-up Capability at Hnp.Conclusions Reached by NRC Staff in SER Contained in Issuance of License Amend 193 Not Impacted & & Remain Valid

ML20236X125
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	07/30/1998
From:	Mellor R CONNECTICUT YANKEE ATOMIC POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
CY-98-127, NUDOCS 9808070153
Download: ML20236X125 (3)

Text

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CONNECTICUT YANKEE ATOMIC POWER COMPANY HADDAM NECK PLANT 362 INJUN HOLLOW ROAD EAST HAMPTON, CT 06424-3099 July 30,1998 Docket No. 50-213 CY-98-127 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Haddam Neck Plant Information on Spent Fuel Pool Makeuo Capability The purpose of this letter is to provide clarifying information on the spent fuel pool make-up capabilit Amendment 193'y was at the by issued Haddam the NRCNeck basedPlant (HNP). Recently, upon information provided byLicense 2

Connecticut Yankee Atomic Power Company (CYAPCO) on May 30,1997 . The Safety Evaluation Report (SER) for this license amendment stated in part that "if offsite power cannot be reestablished within approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> after a loss of normal power, limited makeup water to the fuel pool could be provided by the gravity .

feed from a tank.. ." This specific statement is no longer accurate as the function of j the refueling water storage tank (RWST), which was originally designated for this )

purpose, was replaced by the demineralized water storage tank (DWST) on October 7,1997, using the 10CFR50.59 process. However, the overall conclusion contained in the license amendment SER is correct.

Discussion O

Prior to the submittal in May 1997, the licensing basis for spent fuel pool makeup was discussed, in part, in the SER for License Amendment 188 . The licensing i basis included a normal makeup from the non-seismic primary water storage tank <)

(1) USNRC Letter to R. A. Mellor, " Issuance of Amendment No.193 to Facility Operating License No. DPR-61, Connecticut Yankee Atomic Power Station",

dated June 30,1998.

(2) CYAPCO Letter CY-97-006 to USNRC, " Proposed Revision to Operating License and Technical Specifications Defueled Operating License and Technical Specifications", dated May 30,1997.

(3) USNRC Letter to R. E. Busch, " Issuance of Amendment", dated January 22,1996.

98o807o153 98073o PDR ADOCK 0500o213 M PDR

, Unit:d Stat:s Nuclser Regulatory Commission CY-98-127/Page 2

. (PWST), with contingency makeup capability from either a seismically qualified tank l with or without a loss of offsite power or the fire water system powered by a diesel i pump. The RWST was designated as this seismically qualified tank. A purification l pump, which can be manually energized from an on-site diesel generator, could have )

been used to transfer water from the RWS1 to the fuel pool when the RWST was in '

service. This mnkeup methodology was described in plant procedures. )

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The preparation of the license amendment submittal letter for the defueled technical '

specifications contained the statement that " limited make-up water to the fuel pool could be provided by gravity feed". The limited capability was available by gravity feed only if the RWST was nearly full. Lower water levels in the spent fuel pool would allow more of the water in the RWST to gravity feed. While this gravity feed  ;

capability was an available alte.rnative through a valvo alignment, the primary method of transfer during a loss of normal power was repowering the system purification pump. The other " backup" supply was river water via the fire water system. This

" backup" has not changed.

On October 7,1997, CYAPCO approved a safety evaluation to delete the RWST as I the seismically qualified source of spent fuel pool makeup and substitute the DWST -  :

as the seismically qualified source. This safety evaluation also provided the basis for revising plant procedures to i_nclude a section that describes the methodology for i transferring demineralized water from the DWST to the fuel pool using hoses and a i portable gasoline-driven pump. This methodology provides a means to add sufficient '

water flow to the spent fuel pool to provide for makeup due to maximum evaporative losses during or following a seismic event without the need for on-site or off-site power sources. This safety evaluation changed the design basis for post-seismic fuel pool makeup of demineralized water from the RWST to the DWST. The normal  ;

makeup source of demineralized water remains the PWST. Note that the RWST, although not in service, is currently classified as available.

A brief description of this safety evaluation was included in the annual report submitted to the NRC on February 23,19984.

Conclusion Multiple fuel pool makeup capabilities are provided to replace evaporative losses during a loss of offsite power event and are not dependent on the limited gravity feed capability. Makeup water to the pool is available from the DWST using hoses and a portable gasoline-driven pump, and the backup supply using the river water via the fire water system.

(4) CYAPCO Letter CY-98-010 to USNRC, " Annual Report", dated February 23,1998.

Unit:d Stat s Nucl ar Regul: tory Commission CY-98-127/Page 3

. Based on the above discussion on the adequacy of spent fuel pool makeup capability to replace evaporative losses in the event of a loss of offsite power event, the conclusions reached by the NRC staff in the SER are not impacted and remain valid.

Should you have any questions on the above, or desire additional information, please contact Mr. G. P van Noordennen at (860) 267-3938.

Very truly yours, CONNECTICUT YANKEE ATOMIC POWER COMPANY

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U R. A. Mellor Vice President - Operations and Decommissioning cc: H. J. Miller, Region i Administrator T. L. Fredrichs, Project Manager, Haddam Neck Plant W. J. Raymond, Senior Resident Inspector, Haddam Neck Plant D. Galloway, CT DEP Monitoring and Radiation Division l

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