ML20205L169

Proposed Tech Specs,Removing Description of High Pressurizer Water Level & Modifying Description of Main Coolant Sys High Pressure

ML20205L169
Person / Time
Site:	Yankee Rowe
Issue date:	10/21/1988
From:	YANKEE ATOMIC ELECTRIC CO.
To:
Shared Package
ML20205L166	List: ML20205L163 ML20205L169
References
NUDOCS 8811010499
Download: ML20205L169 (3)

Text

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LIMITING SAFETY SYSTEM SETTINGS BASES Low Main Coolant Flow (Steam Generator 6P)

The Low Main Coolant Flow trips provide core protection in the event of a loss of one or more main coolant pumps.

Above a power of 15 MWE, with 4 main coolant pumps operating, an automatic reactor trip will occur if the flow in any two loops drops below 80%

of nominal full loop flow and, with 3 main coolant pumps operating, automatic reactor trip will occur if the flow in any single operating loop dropa below 80% of nominal full loop flow.

The setpoints specified are consistent with the value assumed in the accident analysis.

Low Main Coolant Flow (Main Coolant Pump Current)

The Low Main Coolant Flow trips provide core protection in the event of a loss of one or mor main coolant pumps.

Above a power of 15 MWE, with 4 main coolant pumps operating, an automatic trip will occur if the main coolant pump motor current is outside the limits on any two pumps, and with 3 main coolant pumps operating, automatic trip will occur if the main coolant pump motor current is outside the limits on any operating pump. The setpoints specified are consistent with the value assumed in the accident analysis.

Main Coolant System Low Pressure The Main Coolant System Low Pressure trip is provided to prevent operation in the pressure range in which DNBR is less than 1.30 ensuring that the thermal and hydraulic limits assumed in the accident analysis are not exceeded. This Low Pressure trip provides protection by tripping the reactor in the event of a loss of main coolant pressure.

YANKEE-ROWE B 2-4 Amendment No. 69

] ?l2 $d10499 883023 ADOCK 05000029 PNV 1

r LIMITING SAFETY SYSTEM SETTINGS jfg1S__

Steam Generator Water Level The Low Steam Generator Water Level trip provides core protection by preventing operation with the steam generator water level below the minimum volume required for adequate heat removal capacity. The specified setpoint provides allowance that there will be sufficient water inventory in the steam generators at the time of trip to provide 15 minutes, as assumed in the accident analysis, for starting delays of the emergency feedwater. system.

Turbine and Generator Trip A Turbine or Generator Trip causes direct reactor trip when operating above 15 MWe, Each of the turbine trips provide turbine protection and reduce the severity of the ensuing transient. No credit was taken in the accident analyses for operation of these trips. Their functional capability is required to enhance the overall reliability of the Reactor Protection System.

Main Steam Isolation Trip A Main Steam Isolation Trip closes the main steam line nonreturn valves and causes a direct reactor trip.

This trip reduces the severity of the cooldown and the ensuing transient effects resulting from a main steam line break. This trip also serves to assure the availability of a secondary system heat sink following a seismic event, until the Safe Shutdown System is available to provide feedwater to the steam generators.

Its functional capability enhances the overall reliability of the Reactor Protection Syster..

Hain Coolant System High Pressure The Main Coolant System High Pressure trip acts in conjunction with the pressurizer safety valves to ensure protection against Main Coolant System overpressurization caused by a loss of load incident or an uncontrolled rod withdrawal event.

YANKEE-ROVE B 2-5 Amendment No di 94

g N

7;p TABLE 4.3-1 a

REACTOR PROTECTIVE SYSTEM INSTRUMENTATION SURVEILLANCE REQUIREMENTS s:

m CHANNEL MODES IN WHICH CHANNEL CHANNEL FliNCTIONAL SURVEILIANCE FUNCTIONAL UNIT CHECK CALIERATION

_ TEST REQUIRED 1.

h nual Reactor Trip NA NA S/U(I)

NA 2.

Power Range. Neutron Flux and Intermediate Power Range.

Neutron Flux S

D(2). R(5) g(6)

1. 2 and

• 3.

Intermediate Range. Neutron Flux.

High Startup Rate S

R(5)

M

1. 2 and

• w 4.

Source Range Neutron Flux S

R(5)

S/U(I)

2. 3. 4. 5 and

• s.

w 5.

Iow hin Coolant Flow (SCAP)

S R(4)

M(3) 1 a

co 6.

Iow h in Coolant Flow. Systems A and B (MC Pump Current)

S R

M 1

7.

High h in Coolant System Pressure S

RI4)

M

1. 2 8.

Iow hin Coolant System Pressure S

RIO)

M

' 2 9.

Intentionally Blank l

10.

Iow steam Cenerator Water Iovel S

R(4)

M 1

S.

Eo ew O

k h

.