ML19312B809

Proposed Tech Spec 3.3 Incorporating New Tech Spec 3.3.8 Requiring Operability of Three HPI Pumps for Each Unit During Power Operation Above 60% Full Power

ML19312B809
Person / Time
Site:	Oconee
Issue date:	04/20/1978
From:	DUKE POWER CO.
To:
Shared Package
ML19312B805	List: ML19312B804 ML19312B809
References
NUDOCS 7911190588
Download: ML19312B809 (2)

Text

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() 3.*3.6 Exceptions to 3.3.5 shall be as follows: ,

(a) Both core flooding tanks shall be operational above 800 psig.

(b) Both motor-operated valves associated with the core flooding tanks shall be fully open above 800 psig.

(c) One pressurt <nstrument channel and one level instrument channel per core floc tank shall be operable above 800 psig.

(d) One reactor building cooling fan and associated cooling unit shall be permitted to be out of service for seven days provided both reactor building spray pumps and associated spray nozzle headers are in service at the same time.

(e) If the requirements of Specification 3.3.1(f) are not met, the borated water storage tank shall be considered unavailable and action shall be initiated in accordance with Specification 3.2.

3.3.7 Prior to initiating maintenance on any of the co=ponents, the dupli-cate (redundant) component shall be tested to assure operability.

3.3.8 (a) Reactor power shall not be increased above 60% FP unless three HPI pumps and two EPI flow paths are operable.

(b) During power operation above 60% FP, tests or =aintenance shall be allowed on any one HPI pu=p, provided two trains of the HPI system are operable. If the inoperable HPI pump is not restored to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, reactor power shall be reduced below 60% F? within an additional 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

(c) If during power operation above 60% FP a high pressure injection flow path becomes inoperable, reactor power shall be reduced below 60% FP within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

Bases The requirements of Specification 3.3 assure that, before the reactor can be

=ade critical, adequate engineered safety features are operable. Two high pressure injection pumps and two low pressure injection pu=ps are required (except as specified in Specification 3.3.8 and as discussed further on in these bases.) However, only one of each is necessary to supply emergency coolant to the reactor in the event of a loss-of-coolant accident. Both core flooding tanks are required as a single core flood tank has insufficient in-ventory to reflood the core. (1)

The barated water storage tanks are used for two purposes:

(a) As a supply of borated water for accident conditions.

(b) As a su7 ply of bor;ted water for flooding the fuel transfer canal during refueling operation. (2) i l

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O.J T[ tree-hundredandfiftythousand(350,000) gallons of borated water (a level of 46 feet in the BWST) are required to supply emergency core cooling and reactor building spray in the event of a loss-of-core cooling accident. This amount fulfills requirements for em'ergency core cooling. The borated water storage tank capacity of 388,000 gallons is based on refueling volume require-ments. Heaters maintain the borated water supply at a temperature to prevent freezing. The boron concentration is set at the amount of boron required to maintain the core 1 percent subcritical at 70 F0 without any control rods in the core. This concentration is 1,338 ppm boron while,the minimum value specified in the tanks is 1,800 ppm boron.

The spray system utili:es coc=on suction lines with the low pressure injection system. If a single train of equipment is removed from either system, the other train must be assured to be operable in each system.

When the reactor is critical, maintenance is allowed per Specification 3.3.5 and 3.3.6 provided requirements in Specification 3.3.7 are cet which assure operability of the duplicate components. Operability of the specified components shall be based on the results of testing as required by Techn' cal Specifi-cation 4.5. The maintenance period of up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is acceptable if the operability of equipment redundant to that removed from service is demonstrated immediately prior to removal. The basis of acceptability is a likelihood of failure within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following such demonstration.

It has been shown for the worst design basis loss-of-coolant accident (a 14.1 f t 2 hot leg break) that the reactor building design pressure vill not be exceeded with one spray and two coolers operable. Therefore, a =aintenance period of seven days is acceptable for one reactor building cooling fan and its associated cooling unit. (3)

In the event that the need for emergency core cooling should occur, functioning of one train (one high pressure injection pump, one low pressure injection pu=p, and both core flooding tanks) will protect the core and in the event of a main coolant loop serverence, limit the peak clad temperature to less than 2,2000 F and the =etal-water reaction to that representing less than 1 percent l of the clad.

Three low pressure service water pumps serve Oconee Units 1 and 2 and two low pressure service water pumps serve Oconee Unit 3. There is a =anual cross-connection on the supply headers for Units 1, 2, and 3. One low pressure service water pu=p per unit is required for normal operation. The normal operating requirements are greater than the emergency require =ents following a loss-of-coolant accident.

The require =ent to have three HPI pu=ps and two EPI flow paths operable during power operation above 60% FP (Specification 3.3.8) is based on considerations of a 0.04 square foot break at the reactor coolant pump discharge piping for which two HPI trains (two pumps and two flow paths) are required to assure adequate core cooling. The analysis of this break indicates that for operation at or below 60% FP only a single train of the HPI system is needed to provide the necessary core cooling.

REFERENCES (1) FSAR, Section 14.2.2.3 (2) FSAR, Section 9.3.2 (3) FSAR, Supplement 13 3.3-4