ML20034B307

Proposed Tech Specs Re HPSI & LPSI Pump Surveillance Frequency

ML20034B307
Person / Time
Site:	Yankee Rowe
Issue date:	04/19/1990
From:	YANKEE ATOMIC ELECTRIC CO.
To:
Shared Package
ML20034B301	List: ML20034B300 ML20034B307
References
NUDOCS 9004260362
Download: ML20034B307 (4)

Text

PROPOSED CHANGE;234 SYNOPSIS This proposed change is prepared to bring the High Pressure Safety. Injection (HPSI) and LPSI pump surveillance f requency requirements in line with the Standard Technical Specifications for Westinghouse Pressurized Water Reactors (PWRs) contained in NUREG-0452. Revision 4, while providing for re-establishment of ASME XI inservice testing. reference values as provided for in'the code. NUREG-0452 requires surveillance of these pumps only when they are being tested to meet the in-service testing required by Section XI of the ASME Boiler and Pressure Vessel Code in effect for each' specific plant.

SUMMARY

The code in effect for Yankee is the 1977 edition through the 1978 summer addendum which requires monthly pump testing. However, editions and addenda to the code after this have changer pump testing to quarterly. Yankee's In-service Testing Program is being updated to a later edition of the code which will require quarterly pump testing.

Reference (c) requested specific code relief to perform quarterly pump inservice testing on an interim basis until.the program is formally updated. This proposed change will bring Yankee's pump testing requirements in line with the Westinghouse Standard Technical Specifications of NUREG-0452, the intent of which is to link the Emergency Core Cooling System (ECCS) pump surveillance to the ASME Section XI Program.

The minimum discharge pressure requirement is being deleted from surveillance requirement in 4.5.2a because ECCS pump operational readiness is verified through implementation of the Inservice Testing Program as delineated in Specification 4.0.5.

Removal of minimum discharge pressure values will provide for re-establishment of hydraulic reference values as allowed by ASME XI.without having to revise.

plant Technical Specification each time.

For example, plant modifications are scheduled to be implemented during the

('

next refueling outage which will facilitate more meaningful substantial flow 5

testing of the YNPS ECCS pumps. The resultant operating data will be more 1

'f indicative of the pump hydraulic and mechanical condition. These changes will necessitate establishing new ASME XI hydraulic reference values for differential pressure and flow for each pump. Since operational readiness of the pumps is demonstrated through compliance with Specification 4.0.5 by the plant Inservice Testing Program, there is no need for duplicate or supplemental Technical Specification surveillances.

The Inservice Testing Program at YNPS will continue to ensure that pump operational readiness criteria are consistent with the requirements of ASME XI.

System performance surveillance will continue to be conducted in accordance with plant Technical Specifications. 7 f WPP72/32 9004260362 900419 PDR ADOCK 05000029 P

PDC

c r

PROPOSED CHANGE 234 SYNOPSIS (Continued)

SAFETY CONSIDERATIONS This change is requested in order to revise the HPSI and LPSI pump surveillance requirements in Section 4.5.2a of the YNPS Technical Specifications. As such, this proposed change would not:

1.

Involve a significant increase in the probability or consequences of an accident previoucly evaluated. This change only revises the surveillance requirements for these pumps. -The purpose of these surveillance requirements is to prove that the pumps are operable. The revised surveillance requirements will continue to demonstrate pump operability.

2.

Create the possibility of a new or different kind of accident from any previously evaluated. Verification of pump operability is maintained while requiring no' system configuration changes in order to perform surveillance testing, which adversely affect system functional performance.

3.

Involve a.significant reduction in a margin of safety. Verification of pump operability is maintained. The Inservice Testing Program at YNPS will continue to ensure that pump operational readiness criteria are consistent with the requirements of ASME XI.

System performance surveillance will continue to be conducted in accordance with plant Technical Specifications.

Based on the discussion above, it is concluded that there is reasonable assurance that operation of the Yankee plant, consistent with the proposed Technical Specifications, will not endanger the health and safety of the public.

I WPP72/32

SyRVEILLANCE REQUIREMENTS 4.5.2 Each ECCS safety injection subsystem, the recirculation subsystem, and the long-term hot leg injection subsystem shall be demonstrated OPERABLE:

a.

By testing each of the following pumps pursuant to Specification 4.0.5:

1.

High Pressure Safety Injection Pumps 2.

Low Pressure Safety Injection Pumps b.

At least once per 31 days by:

1.

Verifying that the following valves are in the indicated positions with power to the valve operators removed by opening at least two breakers in series:

Valve Number Valve Function Valve Position

a. CH-MOV-522

a. Charging Header /LPSI

a. Closed Isolation YANKEE-ROWE 3/4 5-4 Amendment No. 35, 52, 92, 120, 13I

4 EMERGENCY CORE COOLING SYSTEMS BASES i

ECCS SUBSYSTEMS (Continued)

With the Main Coolant System temperature and pressure below 330*F, and i

1,000 psig,:respectively, one OPERABLE ECCS safety injection subsystem, with the OPERABLE recirculation subsystem and the OPERABLE long-term hot leg injection subsystem, is acceptable without single failure consideration on the basis of the stable reactivity condition of the reactor, the decreased probability of a LOCA, and the limited core cooling' requirements because of.

the neglf.gible energy stored in the primary coolant under these conditions.

The Surveillance Requirements provided to ensure OPERABILITY of each component ensures that, at a minimum, the assumptions used in the safety analyses are met and that subsystem OPERABILITY is. maintained.

Complete system tests cannot be performed when the reactor is operating because of their inter-relation with operating systems. The method of assuring operability of these systems is'a combination of complete system tests performed during refueling shutdowns and inservice testing of active system components (pumps and valves) during reactor operation. The test interval is based on the judgment that more frequent testing would not significantly increase reliability.

Some subsystems' power operated valves fail to meet single failure criteria and removal of power to these valves is required.

In order to eliminate potential for reactor vessel low temperature overpressurization by the inadvertent operation of ECCS pumps, the pump circuit breakers are opened and locked in the racked-out position or removed from the breaker cubicles.

Also selected SIS isolation valves are positioned to remove the possibility of an overpressurization event during that portion of MCS heatup and cooldown when an inadvertent injection could result in an overpressure event.

3/4.5.4 SAFETY INJECTION TANK The OPERABILITY of the Safety Injection Tank (SIT) as part of the ECCS ensures that a sufficient supply of borated water is available for injection by the ECCS in the event of a LOCA.

The limits on SIT minimum volume and boron concentration ensure that 1) sufficient water is available within containment to permit recirculation cooling flow to the core, and 2) the reactor will remain suberitical in the cold condition following mixing of the SIT and.the Main Coolant System water volumes with all control rods inserted except for the most reactive control assembly. These assumptions are consistent with the LOCA analyses, which is based on allowing a minimum of 77,000 gallons to be injected by the safety injection subsystems before the recirculation is manually established.

LOCA analyses show that an injection of 77,000 gallons is sufficient to limit core temperatures and containment pressure for the full spectrum of pipe ruptures.

This leaves up to 40,000 gallons in the SIT as reserve. The boron concentration of 2,200 ppm is the highest value assumed in any accident analysis. The SIT water temperature of 120*F to 130*F ensures that the reactor vessel is not subjected to conditions that could exceed the NDT provisions of the ASME Code after a severe transient.

YANKEE-ROWE B 3/4 5-2 Amendment No. 52, 59, $1

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