ML20204H368

Proposed Tech Spec,Revising Definition of Operable & Specifying Time Allocated to Cold Shutdown When Required Safety Function Not Maintained Due to Equipment Failure or Maint Outage

ML20204H368
Person / Time
Site:	Rancho Seco
Issue date:	10/30/1984
From:	SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:
Shared Package
ML20204H344	List: ML20204H338 ML20204H368
References
TAC-43042, NUDOCS 8411120271
Download: ML20204H368 (4)

Text

... RANCHO SECO UNIT 1

i. TECHNICAL SPECIFICATIONS'

. Definitions

^

140 F. Pressure is defined' by Specification 3.1.2. A refueling shutdown refers'to a shutdown to replace or rearrar.]e all or a portion of the fuel assemblies and/or control rods.

1.2.7 Refueling Operation An operation involving a change in core geometry by manipulation of fuel or control rods when the reactor vessel head is removed.

1.2.8 Refueling Interval

. Time between nomal refuelings of the reactor, not to exceed 24 months for the first refueling and 18 months thereafter without prior approval of the NRC.

1.2.9 Startup The reactor shall be considered in the startup mode when the shutdown margin is reduced with the intent of going critical.

1.2.10 Remain Critical A technical specification that requires that the reactor shall not remain critical shall mean that an uninterrupted nomal hot shutdown procedure will be ' completed within 12- hours.

1.2.11 T ay At operating conditions TAVG is defined as the arithmetic average of the coolant temperatures in the hot and cold legs of the loop with the greater number of reactor coolant pumps operating, if such a distinction of loops can be made.

1.2.12 Heatup - Cooldown Mode The heatup-cooldown mode is the range of reactor coolant temperature greater than 200 F and less than 525 F.

1.3 OPERABLE A component or system is operable when it is capable of perfoming its intended function within the required range. 'The component or system shall be considered to have this capability when: (1) it satisfies the limiting conditions for operation defined in Specification 3, and (2) it has been tested periodically in accordance with Specification 4, and has met its perfomance requirements, (3) the system has available its nomal and emergency sources of power. When a system or component is determined to be inoperable solely because its nomal power source is inoperable or its emergency power source is inoperable, it may be considered OPERABLE for the purpose of satisfying the requirements of its applicable Limiting Condition for Operation provided its redundant system or couponent is OPERABLE with an 0PERABLE nomal and emergency power source, and (4) its required auxiliaries are capable 'of perfoming their intended function.

Proposed Amendment 101, Revision 1 1-2 8411120271 841030.

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r RANCHO SECO UNIT 1 TECHNICAL SPECIFICATIONS' Definitions 1.4 PROTECTION INSTRUMENTATION LOGIC 1.4.1 Instrument Channel An instrument channel is the combination of sensor, wires, amplifiers and output devices which are connected for the purpose of measuring the value of 8 process variable for the purpose of observation, control and/or protection. An instrument channel may be either analog or digital.

1.4.2 Reactor Protection System The reactor protection system is shown in figures 7.1-1 and 7.2-2 of the FSAR. It is that combination of protective channels and associated circuitry which fonas the automatic system that protects the reactor by control rod trip. It includes the four protection channels, their associated instrument channel inputs, manual trip switch, all rod drive control protective trip breakers and activating relays or coils.

l Proposed Amendment 101, Revision 1 1-2a

RAl4CHO SECO UNIT 1 TECHNICAL SPECIFICATIONS Limiting Concitions for Operation 3.3.3 Prior to initiating maintenance on any of the components, the duplicate (redundant) components shall be tested to assure operability, with the component on which maintenance is being perfccm. emoved from service.

3.3.4 During power operation, hot standby, hot shutdown or startup conditions, the primary coolant system pressure isolation valves shall be functional as follows:

1. All pressure isolation valves listed in Table 3.3-1 shall be functional as a pressure isclation device, except as specified in 3.3.4.2. Valve leakage shall not exceed the amounts indicated.

2. In the event that integrity of any pressure isolation valve specified in Table 3.3-1 cannot be demonstratea, reactor operation raay continue, provided that at least two valves in an each remainhigh in, pressure the modeline having a non-functional corresponding valve to the isolated condition. are in(a)d

3. If Specifications 3.3.4.1 and 3.3.4.2 cannot be met, a shutcoun shall be initiated, the reactor shall not remain critical and shall oe brought to a cold shutdown condition within an additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

3.3.5 Should the redundant equipment or system as specifiec in Section 3.3.3 become inoperable, as defined in Specification 1.3, the reactor shall not remain critical and be placed in colo shutuown condition within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.

Bases The requirements of Specification 3.3.1 assure that, before the reactor can be made critical, adequate safety features are operable. Two high pressure injection pumps and two decay heat removal pumps are specified. 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 g a single core flood tank has insufficient inventory to reflood thecore.LgI The borated water storage tank is used for two purposes:

A. As a supply of borated water for accident conditions.

B.

As a supply during of borated refueling water (2)for flooding the fuel transfer canal operation.

390,000 gallons of borated water are supplied for emergency core cooling and Reactor Building spray in the event of a loss-of-core coolant accident. This amount fulfills requirements for emergency core cooling. The borateo water storage tank minimum volume of 390,000 gallons is based on refueling volume requi rements. Heaters maintain the borated water supply at 6 temperature to prevent f reezing. The boron concentration is set at the amount of boron required to maintain the core 1 percent subcritical at 70'F without any control rods in the core. This concentration is 1585 ppm boron while the minimum value specified in the tanks is 1,600 ppu boron.

(a) Motor operated valves shall be pieceu in the clusea position ar.u power supplies deenergized.

F.rcposed Amendaent 101, Revision 1 1M - - - - - - - - - - - - - - - - - - _ _

~ RANCHO SECO UNIT 1 TECHNICAL SPECIFICATI0W g , ing Conditions for Operation The requireinent that one BWST isolation valve shall be open assures a static head to the injection pump not l'ined up to the makeup tank.

The post accident Reactor Building cooling may be accomplished by two spray units or by a combination of two emergency cooling units and one spray unit.

u The specified requirements assure that the reouired post accident components are available'.

Tite spray system utilizes common suction lines with the decay heat removal system. If a single train of equipment is removed from either system, the other train must be assored to be operable in each system.

When the. reactor is critical, maintenance is allowed per Specification 3.3.2 provided requirements in Specification 3.3.3 are uet which assure operability of the duplicate components. Operability of the specified components shall-be based on the results of testing as required by Technical Specification 4.5.

The maintenance period of up to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> is acceptable if the opera!ility of

' equipment redundant to that removed from service is oemonstrated immediately subsequent to removal. The basis of acceptability is a low likelihood of failure within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> following such demonstration.

In the event that the need for emergency core cooling should occur, functioning .of one train (one high pressure injection pump, una decay heat

, removal pump anii both core flooding tanks) will protect the core and in the event of a main coolant loop severance, limit the peak clad tempe ature to less than 2,200*F and the metal-water reaction to less than 1 percent of the clad.

The nuclear service ' cooling water system consists of two independent, full capacity removal.

(3sLOO percent redundant systems, to. ensure continuous heat The requirements of Specification 3.3.4 assure that the decay heat removal system will not be overpressurized, reculting in a LOCA that bypasses containment. Two in-series check valves function as a pressure isolation barrier between the high pressure reactor coolant system and the lower pressure . decay heat removal system extending beyond containment. Valve leakage limits provide assurance that the valves are perfoming their intended f ' isolation function.

The requirements of Sp'ecification 3.3.5 assure that, should all trains of a Safety Features equipment.or system specified in this section 3.3 become inoperable as defined in Specification 1.3,'the reactor will be placed in a cold shutdown condition. It is necessary for a component or system to have available its normal and emergency sources of power. When a system or component is detemined to be inoperable solely because its nomal or emergency power source is inoperable, it may be considered OPERABLE for the purpose of satisfying the requirements of its applicable Limiting Conditions for Operation provided its redundant system or component is OPERABLE with an OPERABLE nomal and emergency power source.

REFERENCES (1) FSAR, paragraph 6.2.1 (2) FSAR, paragraph 9.5.2 (3)- FSAR, paragraph 9.4.1 Proposed Amendment 101, Revision 1 3-22

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