ML18141A580

Proposed Tech Specs Changing Status of Opposite Unit Auxiliary Feedwater Pump from Operable to Available & Adding Spec to Provide Opposite Unit Auxiliary Feedwater Pump Down Time

ML18141A580
Person / Time
Site:	Surry
Issue date:	04/05/1984
From:	VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML18141A579	List: ML18141A578 ML18141A580
References
NUDOCS 8404130218
Download: ML18141A580 (8)

Text

e e TS 3.6-1 3.6 TURBINE CYCLE Applicability Applies to the operating status of the Main Steam and Auxiliary Feed Systems.

Objective To define the conditions required in the Main Steam System and Auxiliary Feed System for protection of the steam generator and to assure the capa-bility to remove residual heat from the core during a loss of station power.

Specification A. A unit's Reactor Coolant System temperature or pressure shall not exceed 350°F or 450 psig, respectively, or the reactor shall not be critical unless the five main steam line code safety valves asso-ciated with each steam generator in unisolated reactor coolant loops are operable.

B. To assure residual heat removal capabilities, the following condi-tions shall be met prior to the commencement of any unit operation that would establish reactor coolant system conditions of 350°F and 450 psig which would preclude operation of the Residual Heat Removal System.

1. Two motor driven auxiliary feedwater pumps shall be operable, and one of three auxiliary feedwater pumps for the opposite unit shall be available*.

• Available means (1) operable except for automatic initiation instrumentation, (2) offsite or emergency power source may be inoperable in cold shutdown, and (3) it is capable of being used with the opening of the cross-connect.

( 84 041302 ia--040405 PDR ADOCK 05000280 p PDR

e TS 3.6-2

2. A minimum of 96,000 gallons of water shall be ~vailable in the tornado missile protected condensate storage tank to supply emergency water to the auxiliary feedwater pump suctions. A minimum of 60,000 gallons of water shall be available in the tornado protected condensate storage tank of the opposite unit to supply emergency water to the auxiliary feedwater pump suction of that unit.

3. All main steam line code safety valves, associated with steam generators in unisolated reactor coolant loops, shall be oper-able.

C. Prior to reactor power exceeding 10%, the steam driven auxiliary feedwater pump shall be operable.

D. System piping, valves, and control board indication required for the operation of the components enumerated. in Specifications 3. 6. B. 1, 3.6.B.2, 3.6.B.3 and 3.6.C shall be operable with the system piping, valves, and control board indication required for the operation of the opposite unit auxiliary feedwater pump available*.

E. The iodine - 131 activity in the secondary side of any steam gene-rator, in an unisolated reactor coolant loop, shall not exceed 9 curies. Also, the specific activity of the secondary coolant system shall be~ 0.10 µCi/cc DOSE EQUIVALENT I-131. If the specific activity of the secondary coolant system exceeds O.10 µCi/ cc DOSE EQUIVALENT I-131, the reactor shall be shut down and cooled to 500°F or less within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> after detection and in the cold shutdown condition within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

• Available means (1) ope.rable except for automatic initiation instrumentation, (2) offsite or emergency power source may be inoperable in cold shutdown, and (3) it is capable of being used with the opening of the cross-connect.

e e TS 3.6-3 F. With one auxiliary feedwater pump inoperable, restore at least three auxiliary feedwater pumps (two motor driven feedwater pumps and one steam driven feedwater pump) to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in hot shutdown within the following 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

G. The requirements of Specifications 3.6.B.l and 3.6.D above con-cerning the opposite unit's auxiliary feed water pumps and associated piping, valves, and control board indications may be modified to allow the following components to be unavailable.

1. The opposite unit's auxiliary feed water pumps may be unavail-able for a period not to exceed 7 days provided immediate attention is directed to making repairs. If not available within 7 days, be in at least hot shutdown within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in cold shutdown within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

2. The system piping, *valves, and control board indication for operation of the opposite unit's auxiliary feed water pumps may be unavailable for a period not to exceed 7 days provided immediate attention is directed toward making repairs. If not available within 7 days, be in at least hot shutdown within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in cold shutdown within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

H. The requirements of Specification 3.6.B.2 above may be modified to allow utilization of protected condensate storage tank water with the auxiliary steam generator feed pumps provided the water level is maintained above 60,000 gallons, sufficient replenishment water is available in the 300,000 gallon condensate storage tank, and replen-ishment of the protected condensate storage tank is commenced within two hours after the cessation of protected condensate storage tank water consumption.

Basis A reactor which has been shutdown from power requires removal of core residual heat. While reactor coolant temperature or pressure is> 350°F or 450 psig, respectively, residual heat removal requirements are normal-

e e TS 3.6-4 The capability to supply feedwater to the generators is normally provided by the operation of the Condensate and Feedwater Systems. In the event of complete loss of electrical power to the station, residual heat removal would continue to be assured by the availability of either the steam driven auxiliary feedwater pump or one of the motor driven auxil-iary feedwater pumps and the 110,000-gallon condensate storage tank. In the event of a fire which would render the auxiliary feedwater pumps inoperable, residual heat removal would continue to be assured by the availability of either the steam driven auxiliary feedwater pump or one of the motor driven auxiliary feedwater pumps from the opposite unit.

A minimum of 92,000 gallons of water in the 110,000-gallon condensate tank is sufficient for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of residual heat removal following a reactor trip and loss of all offsite electrical power. If the protected condensate storage tank level is reduced to 60,000 gallons, the immedi-ately available replenishment water in the 300,000-gallon condensate tank can be gravity-fed to the protected tank if required for residual heat removal. An alternate supply of feedwater to the auxiliary feedwater pump suctions is also available from the Fire Protection System Main in the auxiliary feedwater pump cubicle.

The five main steam code safety valves associated with each steam gene-rator have a total combined capacity of 3,725,575 pounds per hour at their individual set pressure; the total combined capacity of all fifteen main steam code safety valves is 11,176,725 pounds per hour. The ultimate power rating steam flow is 11,167,923 pounds per hour. The combined capacity of the safety valves required by Specification 3. 6 always exceeds the total steam flow corresponding to the maximum steady state power than can be obtained during one, two, or three reactor coolant loop operation.

The availability of the auxiliary feedwater pumps, the protected condensate storage tank, and the main steam line safety valves adequately assures that sufficient residual heat removal capability will be avail-able when required.

e e TS 3.6-5 The availability of the auxiliary feedwater pwnps, the protected condensate storage tank, and the main steam line safety valves adequately assures that sufficient residual heat removal capability will be avail-able when required.

The limit on steam generator secondary side iodine - 131 activity is based on limiting inhalation thyroid dose at the site boundary of 1.5 rem after a postulated accident that would result in the release of the entire contents of a unit's steam generators to the atmosphere. In this accident, with the halogen inventories in the* steam generator being at equilibriwn valves, I-131 would contribute 75% of the resultant thyroid dose at the site boundary; the remaining 25% of the dose is from other isotopes of iodine. In the analysis, one-tenth of the contained iodine is asswned to reach the site boundary, making allowance for plate out and retention in water droplets.

The inhalation thyroid dose at the site boundary is given by:

Dose (rem)= (C) (X/Q) (Doo/At) (B.R.)

(.75) (P.F.)

where: C = steam generator I-131 activity (curies)

X/Q = 8.14 x 10- 4 sec/m 3 Doo/At = 1.48 x 10 6 rem/Ci for I-131 B.R. = breathing rate, 3.47 x 10- 4 m3 /sec from TID 14844 P.F. = plating factor, 10 Asswning the postulated accident, the resultant thyroid dose is 1.5 rem.

The steam generator's specific iodine - 131 activity limit is calculated by dividing the total activity limit of 9 curies by the water volwne of a steam generator. At full power, with a steam generator water volwne of 47.6 M3 , the specific iodine - 131 limit would be .18 µCi/cc; at zero power, with a steam generator water volwne of 101 M3 , the specific iodine - 131 limit would be .089 µCi/cc.

The limitation on secondary system specific activity ensures that the resultant offsite radiation dose will be limited to a small fraction of 10 CFR Part 100 limits in the event of a steam line rupture.

e e TS 3.6-6 REFERENCES FSAR Section 4, Reactor Coolant System FSAR Section 9.3, Residual Heat Removal System FSAR Section 10.3.1, Main Steam System FSAR Section 10.3.2, Auxiliary Steam System FSAR Section 10.3.5, Auxiliary Feedwater System FSAR Section 10.3.8, Vent and Drain Systems FSAR Section 14.3.2.5, Environmental Effects of a Steam Line Break

1 - .- * ~ -

e Attachment 2

e e SAFETY EVALUATION This proposed change revises Specifications 3.6.B.1 and 3.6.D. In the event of a fire on one unit which would render that unit's auxiliary feedwater pumps inoperable, residual heat removal would continue to be assured by the availability of either the steam driven auxiliary feedwater pump or one of the motor driven auxiliary feedwater pumps from the opposite unit. 'This proposed change revises the status of the opposite unit's auxiliary feedwater pump from "operable" to "available". Available is defined as "(1) operable except for automatic inj.tiation instrumentation, (2) offsite or emergency power may be inoperable in cold shutdown, and (3) it is capable of being used with the opening of the cross-connect." This proposed change defines the condition where the opposite unit's auxiliary feedwater pump is available and capable of performing its intended function but not required to meet the strict definition of operable as defined in the Technical Specifications.

This proposed change also adds a specification which allows the opposite unit auxiliary feedwater pump down time for maintenance and repairs. Specific action is provided to be in hot shutdown within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in cold shutdown within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> in the event that the opposite unit auxiliary feedwater pumps and associated piping, valves and controls are unavailable for a period of more than seven days.

This proposed change does not involve a significant hazards consideration.

This change is best encompassed by Example (vi) of the examples provided for guidance by the NRC in the April 6, 1983 FR[14870]; a change which either may result in some probability or consequences of a previously analyzed accident or may reduce in some way a safety margin, but where the results of the change are clearly within the acceptance criteria for the system or component. This proposed change does not degrade the use of the system. Any change to the margin of safety is insignificant because essentially the status of the opposite unit auxiliary feedwater pump is unchanged. The component is still required to be able to perform its intended function. This change is to avoid the possibility of violating a definition of the Technical Specification when the opposite unit is in cold shutdown.

In addition, the editorial changes in this proposed change are encompassed by Example (i) , of the examples provided for guidance by the NRC to determine that a significant hazards consideration is not involved. Example (i) states, A purely administrative change to technical specifications, for correction of errors;in this instance, typographical and minor editorial errors.