ML20085N026

Application for Amends to Licenses NPF-4 & NPF-7,revising Current Tech Specs to Ensure Adequate Monitoring of Groundwater Level for Svc Water Reservoir

ML20085N026
Person / Time
Site:	North Anna
Issue date:	11/07/1991
From:	Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20085N030	List: ML20085N026 ML20085N032
References
91-659, NUDOCS 9111140018
Download: ML20085N026 (7)

Text

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YlRGINIA EllCTRIC AND l'0Wl:R COht!'ANY HICllh10ND, VIRGINIA 23261 November 7, 1991 U.S. Nuclear Regulatory Commission Serial No. 91659 Attention: Document Control Desk NAPS /JYR Washington, D.C. 20555 Docket Nos. 50 338 50 339 License Nos. NPF 4 NPF-7 Gentlemen:-

y_lBGINIA ELECTRIC AND POWER COMPANY MQRTH ANNA POWER STATION UNITS 1 AND 2 PROPOSED TECHNICAL SPECIFICATION CHANGES Pursuant to _10 CFR 50.90, the Virginia Electric and Power Company requests

, ameiidm9nts, in the form of changes to the Technical Specifications, to Operating License Numbers NPF 4 and NPF 7 for North Anna Power Station Units 1 and 2, respectively. The proposed changes will revise the current Technical Specifications to ensure adequate monitoring of groundwater level for the service water reservoir.

A discussion of the proposed changes is provided in Attachment 1. The proposed changes are presented in Attachment 2 for Units 1 and 2, '

respectively.

This request has been reviewed by the Station Nuclear Safety and Operating Committee and the Management Safety Review Committee. It has been determined that this request does not involve an unreviewed safety question as defined in 10 CFR 50.59 or a significant hazards consideration as defined in 10 CFR 50.92. The basis for our determination that no signification hazards consideration is involved is presented in Attachment 3.

Should you have any_ questions or require additional information, please contact us at your earliest convenience.

Very truly urs,

/ I i/

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W. L. St art Senior Vice President - Nuclear-9111140o18 911107

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Attachments

1. Discussion of Proposed Changes

2. Proposed Technical Specification Change for North Anna Units 1 and 2

3. 10 CFR 50.92 Evaluation oc: U.S. Nuclear Regulatory Commission Region ll 101 Marietta Street, N.W.

Suite 2900 Atlanta, GA 30323 Mr. M. S. Lesser NRC Senior Resident Inspector North Anna Power Station Commissioner Department of Health Room 400 109 Governor Street Richmond, Virginia 23219 l

COMMONWEALTH OF VIRGINIA )

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COUNTYOF HENRICO - )

Tho foregoing document was acknowledged before _ me, in and for the County and Cominonwealth aforesaid, today by E. W. Harrell, who is Vice President - Nuclear Operations, for W. L. Stowart, who is Senior Vice President - Nuclear, of Virginia. Electric and Power Company. He is duty authorized to e,Mecute and file the foregoing document in behalf of that Company, and the- statements in the document are true to the best of his knowledge and belief.

Acknowledged b'efore me this 'T day of \M n W. An, 19 "\ \.  ;

My Commission Expires: jhoA 3\ ,19 %

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Attachment 1 Discussion of Proposed Changes North Anna Units 1 and 2 Virginia Electric and Power Company l

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DISAUSS10F OF PROPOSED CHAT 1GES Introduction The proposed changes described herein are being made as a result of the replacement of several plezometers with open tubo devices that use a conductivity coll. These devices were Installed under design change package DCP 90 0013," Service Water Reservoir Addition."

Currently, Technlcal Specification 3/4.7.13, " Groundwater Level Service Water Recorvoir," requires monitoring various pneumatic piezometers around the service water reservoir as listed in Technical Specification Table 3.7 6. This amendment will delete several plezometers which have boon replaced by the open tube devices and add the replacement devices. The Surveillance Requirements will also be modified to clarify that at least one OPERABLE piezomoter or open tubo device in each zone listed in the specification (pump house, valve house, and southeast side of reservoir) must be monitored. In addition, the Action statement will address the action to be taken if surveillance requirement 4.7.13.1 can not be met. Action statement 3.7.13.c has been added to specify that the provisions of Specification 3.0.4 are not applicable.

In addition, there are two administrative changes to Specification 3/4.13 for North Anna Units 1 and 2 and are as follows:

1) Specification 4.7.13.1 has been divided into two parts, 4.7.13.1 for groundwater level determination, and 4.7.13.2 to measure the outflow of groundwater from the drainage galleries. Both of those requirements are currently presented in Specification 4.7.13.1. This change is administrative in nature only to enhance clarity.

2) Specification 3.7.13, has the phrase "(shared by Units 1 and 2)" added for consistency with the current Unit 2 Specification.

Backaround The service water reservoir is sized to provido a thirty-day supply of cooling water for the safe shutdown and cooldown of the reactor units, in determining the required cepacity of the reservoir, seepage losses were reflected in the mass balance of water in the service water reservoir. The purpose of Technical Specification 3/4.7.13 is to identify either an abnormally high groundwater level that might signify increased seepage of leakage rates from the reservoir which could diminish the supply of cooling water, or a decrease in officiency of either l of the two drainage systems installed to remove accumulated subterranean ground water.

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Technical Sp.tcillcation ChangtA General All Technical Specification changes described herein apply to North Anna Units 1 and 2 unless otherwise noted.

Technical Soecification 3.7.13 The phrase *(shared by Units 1 and 2)"is added to the Limiting Condition for Operation for Unit 1. The phrase "(common to Units 1 and 2)" in the Unit 2 Specification was modified to reflect the same proposed wording as Unit 1.

This was done for consistency and clarification.

The Applicability is unchanged.

The Action statement has been separated into 3.7.13.a and 3.7.13 b and changed to explicitly state that if at least one measurement from each of the zones listed in SR 4.7.13.1 can not be obtained, then a special report should be prepared and submitted to the Commission within 90 days.

Because Action 3,7.13.b specifically addresses not being able to complete S.R. 4.7.13.1 and does not require a reduction in Modes, Action statement 3.7.13.c has been added to specify that the provisions of Specification 3.0.4 are not applicable.

Surveillance Requirement 4.7.13 is divided into two parts, 4.7,13.1 for groundwater level determination, and 4.7.13.2 to measure the outflow of groundwater from the drainage galleries. Both of these requirements are currently presented in Specification 4.7.13.1. These changes enhance clarity and will provide flexibility in the Surveillance Requirement, it is not necessary to monitor all of the measurement locations in order to detect an increasing rate of seepage from the reservoir. An engineering evaluation was performed in DCP 90-0013 showing that a reliable 'eading. from one location in each of the three zones of the dike (the pump house, valve house and the southeast side of the reservoir)is sufficient for detecting leakage from the reservoir. However, the Periodic Test procedure will continue to require that all OPERABLE measurement locations be monitored in order to obtain as much information as possible.

Technical Soecification Table 3.7-6 Table 3.7 6 deletes the piezometers that were removed under DCP 90-001 3 and adds the replacement measurement devices that were installed under the same design change package.

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The replacement devices are of an open tubo design which responds more slowly to changing water levels than the original pneumatic plezometers that ';

were removed. Although the pneumatic type piezometers are better suited for measuring rapidly changing groundwater levels, groundwater levels have historically fluctuated slowly, responding to the seasonal variation in rainfall since the installation of the horizontal drains beneath the pump house and the trench drain which is located at the southeastern toe of the dike. Such slow fluctuations can be readily monitored by open tube devices. Out flow from the drainage galleries drain outlets, which may not exceed the Technical Speeltication Table 3.7 6 limit of 8.5 gallons por minute, can be used to detect a rapidly increasing leakage situation. ,

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