ML20085L969
| ML20085L969 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 06/08/1995 |
| From: | - No Known Affiliation |
| To: | |
| Shared Package | |
| ML20085L973 | List: |
| References | |
| NPF-68-A-086, NPF-81-A-064 NUDOCS 9506280766 | |
| Download: ML20085L969 (2) | |
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3/4.3 INSTRtMENTATION
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BASES
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3/4.3.1 and 3/4.3.2 REACTOR TRIP SYSTEM and ENGINEERED SAFETY FEATURES i
ACTUATION SYSTEM INSTRUMENTATION The OPERABILITY of the Reactor Trip System and the Engineered Safety Features Actuation System instrumentation and interlocks ensures:
(1) the associated ACTION and/or Reactor trip will be initiated when the parameter monitored by each channel or combination thereof reaches its Setpoint (2) the 1
specified coincidence logic and sufficient redundancy is maintained to permit a channel to be out-of-service for testing or maintenance consistent with main-taining an appropriate level of reliability of the Reactor Trip System and Engineered Safety Features Actuation System instrumentation, and (3) sufficient system functional capability is available from diverse parameters.
The OPERABILITY of these systems is required to provide the overall reli-ability, redundancy, and diversity assumed available in the facility design for the protection and mitigation of accident and transient conditions. The inte-grated operation of each of these systems is consistent with the assumptions used in the safety analyses. The Surveillance Requirements specified for these systems ensure that the overall system functional capability is maintained com-parable to the original design standards. The periodic surveillance tests per-formed at the minimum frequencies are sufficient to demonstrate this capability. Specified surveillance intervals and surveillance and maintenance outage times have been determined in accordance with WCAP-10271, "Evaluatia o" Surveillance Frequencies and Out of Service Times for the Reactor Protection Instrumentation System," and supplements to that report.
Surveillance intervals and out of service times were determined based upon maintaining an appropriate level of reliability of the Reactor Protection System and Engineered Safety Features instrumentation. The NRC Safety Evaluation Report for WCAP-10271 and its supplements were provided in letters dated February 21, 1985, from C. O. Thomas (NRC) to J. J. Sheppard (WOG-GP); February 22, 1989, from C. E. Rossi (NRC) to R. A. Newton (WOG); and on April 30, 1990, from C. E.
Rossi to G. T. Goering.
The engineered safety features actuation system does not include an explicit functional unit for the automatic load sequencer. An inoperable load sequencer would affect the ability to detect and respond to a loss of power or undervoltage and thus is included with the instrumentation that must be available to meet the requirements of functional units 6.d.i. and 1.1., as well as 8.a and b.
Since the hardware is the same for each of these functional units, a common action statement is used. The mode of applicability for functional unit 6.d does not include mode 4 since the AFW is not required to be operable in mode 4; therefore, a footnote has been added that r e s to functional unit 8.a and b. which requires the instrumentation to 5. operable in mode 4.
An inoperable automatic load sequencer does. not impact the operability of the automatic actuation logic and actuation relays (functional unit 1.b).
The hardware referred to by this functional unit is not contained within the automatic load sequencer, but in the solid-state protection system. The effects of an inoperable automatic load sequencer is that the associated on site or offsite 4.16 kV emergency power sources may not correctly respond to an ESF or loss of power signal. The appropriate action for an inoperable automatic load sequencer is closely related to the action for an inoperable diesel generator and an associated offsite source with an energized 4.16 kV V0GTLE UNITS - 1 & 2 8 3/4 3-1 Amendment No. 86 (Unit 1)
Amendment No. 64 (Unit 2) 9506280766 950608 DR ADOCK 050004 4
INSTRUMENTATION l
BASES l
REACTOR TRIP SYSTEM AND ENGINEERED SAFETY FEATURES ACTUATION SYSTEM INSTRUMENTATION (Continued)
P-11 With pressurizer pressure below the P-11 setpoint, allows manual block of safety injection actuation on low pressurizer pressure i
signal. Allows manual block of safety injection actuation and steam line isolation on low compensated steam line pressure signal and allows steam line isolation on high steam line negative pressure rate. With pressurizer pressure above the P-11 setpoint, defeats manual block of safety injection actuation on low pressurizer pres-sure and safety injection and steam line isolation on low steam line pressure and defeats steam line isolation on high steam line negative pressure rate.
P-14 On increasing steam generator water level, P-14 automatically trips all feedwater isolation valves, initiates a turbine trip, and i
inhibits feedwater control valve modulation.
The Source Range High Flux at Shutdown Alarm Setpoint is an analysis assumption for mitigation of a Boron Dilution Event in MODES 3, 4, and 5.
3/4.3.3 MONITORING INSTRUMENTATION 3/4.3.3.1 RADIATION MONITORING FOR PLANT OPERATIONS j
The OPERABILITY of the radiation monitoring instrumentation for plant operations ensures that:
(1) the associated action will be initiated when the radiation level monitored by each channel or combination thereof reaches its Setpoint, (2) the specified coincidence logic is maintained, and (3) sufficient redundancy is maintained to permit a channel to be out-of-service for testing or maintenance. The radiation monitors for plant operations senses radiation levels in selected plant systems and locations and determines whether or not predetermined limits are being exceeded.
If they are, the signals are combined into logic matrices sensitive to combinations indicative of various accidents and abnormal conditions. Once the required logic combination is completed, the system sends actuation signals to initiate alarms or automatic isolation action and actuation of Emergency Exhaust or Ventilation Systems.
3/4.3.3.2 MOVABLE INCORE DETECTORS The OPERABILITY of the movable incore detectors with the specified minimum complement of equipment ensures that the measurements obtained from use of this system accurately represent the spatial neutron flux distribution of the core. The OPERABILITY of this system is demonstrated by irradiating each detector used and determining the acceptability of its voltage curve.
For the purpose of measuring F (Z) or F" a full incore flux map is used.
Quarter-core flux maps, as defined in WCAP-808, June 1976, may be used in q
recalibration of the Excore Neutron Flux Detection System, and full incore flux maps or symmetric incore thimbles may be used for monitoring the QUADRANT POWER TILT RATIO when one Power Range channel is inoperable.
V0GTLE UNITS - 1 & 2 8 3/4 3-4 Amendment No. 86 (Unit 1)
Amendment No. 64 (Unit 2)