ML20090G390

Proposed Tech Specs Bases Pages 3/4 3-3 & 3/4 3-4

ML20090G390
Person / Time
Site:	Byron, Braidwood
Issue date:	03/04/1992
From:	COMMONWEALTH EDISON CO.
To:
Shared Package
ML20090G388	List: ML20090G381 ML20090G390
References
NUDOCS 9203120219
Download: ML20090G390 (5)

Text

. _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ . - - _

ATTACilMENT B Changes to Technical Specification Bases s

ReylseLPages: Byron Braidwood B 3/4 3-3 8 3/4 3-3 B 3/4 3-4 0 3/4 3-4

?

9203120219 720304 PDR ADOCK 05000454 P PDR ZNLD/1571/11

.i'

INSTRUMENTATION BASES Engineered Safety Features Actuation Systes Interlocks The Engineered Safety Features Actuation System intorlocks perform the following functions:

P-4 Reactor tripped - Actuates Turbine trip, closes usin feedwater valves 4e-T,yg ble $+tpalat, prevents the opening of the main feedwater valves which were closed by a Safety Injection or High Steam Generator Water Level signal allowsSafetyInjectionblockso thatcomponentscanberesetortrIpped.

Reactor not tripped - prevents manual block of Safety Injection.

P-11 On increasing pressure, P-11 automatically reinstates Safety Injection actuation on low pressurizer pressure and low steamline pressure and automatically blocks steamline isolation on negative steamline pressure rate. On decreasing pressure, P-11 allows the manual block of Safety injection low pressurizer pressure and low steamline pressure and allows steamline isolation on negative steamline pressure rate to become active upon manual block of low steamline pressure $1. '

P-12 On increasing reactor coolant loop temperature, P-12 automatically provides an arming signal to the Steam Dump System. On decreasing reactor coolant loop temperature, P-12 automatically removes the arming signal from the Steam Dump System.

P-14 An increasing steam generator water level P-14 automatically trips all feecNater isolation valves and inhibits feedwater control valve modulation.

3/4.3.3 MONITORING INSTRUMENTATION 3/4.3.3.1 RADIATION MONITORING FOR PLANT OPERATIONS 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 reaches its Setpoint and (2) suffi-cient 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 system sends actuation signals to initiate alarms and automatic actuation of Emergency Exhaust or Ventilation Systems. The radiation monitor Setpoints given in the requirements are assumed to be values established above normal background radiation levels for the particular area. Radiation monitors ORE-AR055 and 56 serve a dual purpose for plant operations as criticality and fuel handling accident sensors. Although these monitors are designed primarily to detcet fuel handling accident releases, they are capable of detecting an inadvertent criticality incident. The Setpoint given in the requirement is established for the fuel handling butiding isolation function but is also adequate for an inadvertent criticality.

BRAIDWOOD - UNITS 1 & 2 B 3/4 3-3 J

INSTRUMENTATION BASES 3/4.3.3.2 W3VABLE 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.

ForthepurposeofmeasuringF(Z)orFhafullincorefluxmapisused.

9 Quarter-core flux maps, as defined in WCAP-8648, June 1976, may be used in 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.

.1/4. 3. 3. 3 SEISMIC INSTRUMENTATION The OPERABILITY of the seismic instrumentation ensures that sufficient capability is available to promptly determine the magnitude of a seismic event' and evaluate the response of those features important to safety. This capability is required to permit comparison of the measured response to that used in the design basis for the facility to determine if plant shutdown is required pursuant to Appendix A of 10 CFR Part 100.

The instrumentation consists of one time-history response spectrum analyzer, a playoack unit, three peak recording accelerometers, and six triaxial acceler-ometers. The above-mentioned equipment, excluding the sensors, is located in the Auxiliary Electrical Room. The remaining sensors are located as follows:

three in containment, two in the Auxiliary Building, and one at ths free field location 38 + 015, 34 + 15E. The peak recording acceleraeters ars passive g S

devices which have no interplay on the rest of the system ad are Ircated on reactor equipment, reactor piping, and outside-containment on tha C tegory I piping.

The triaxial accelerometer is based on three orthogonal force-balanced servo-accelerometers which generate a voltage signal upon stimulation. The voltage signals are transmitted to the time-history recorder in the Auxiliary Electrical Room, digitized, and recorded.e m;;= tic tepe, l The time-history recorder is the master control unit for all control timing signals and system data interface. It also contains the system triggers used to actuate the system. The master control unit continually monitors two of the-sensor inputs, which are processed through the trigger circuits for comparison to the system actuation level. The time-history recorder also has the abity to record both pre- and post-se umic event data. The other key component in the system is the response spectrum analyzer. This unit determines the variation in the maximum response of a single degree-of-freedom system system versus its natural frequency of vibration when either of two designated triaxial accelero-meters is subjected to a time-history motion of the accelerometer.

BRAIDWOOD - UNITS 1 &-2 B 3/4 3-4 =AMNwMT=M. ,28'

INSTRUMENTATION

. BASES Engineered Safety Features Actuation System Interlocks The Engineered Safety Features Actuation System interlocks perfore the following functions:

P-4 Reactor tripped - Actuates Turbine trip, closes main feedwater valves on-T,yg bd ow-Setpoint, prevents the opening of the main feedwater valves which were closed by a Safety Injection or High Steam Generator Water Level signal, allows Safety Injection block so that components can be reset or tripped.

Reactor not tripped prevents manual block of Safety Injection.

P-11 On increasing pressure P-11 automatically reinstates Safety Injection actuation on low pressurizer pressure and low steamline pressure and automatically blocks steamline isolation on negative steamline pressure rate. On decreasing pressure; P-11 allows the manual block of Safety Injection low pressurizer pressure and low steamline pressure and allows steamline isolation on negative steamline pressure rate to become active upon manual block of low steamline pressure SI.

P-12 On increasing reactor coolant loop temperature, P-12 automatically provides an arming signal to the Steam Dump System. On decreasing reactor coolant loop temperature, P-12 automatically removes the arming signal from the Steam Dump System. ,

P-14 An increasing steam generator water level, p-14 automatically trips all feedwater isolation valves and inhibits feedwater control valve modulation.

3/4.3.3 MONITORING INSTRUMENTATION i

3/4.3.3.1 RADIATION MONITORING FOR PLANT OPERATIONS 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 reaches its Setpoint and (2) suffi-cient redundancy is maintained to permit a channel to be out-of-service for testing or maintenanco. The radiation monitors for plant operations senses

.! radiation icvels in selected plant systems and locations and determines whether or not predetermined limits are being exceeded. If they are, the ?ystem sends actuation signals to initiate alarms and automatic act,uation of Emergency Exhaust or Ventilation Systems. The radiation monitor Setpoints given in the requirements are assumed to be values established above normal background radiation levels for the particular area. Radiation monitors ORE-AR055 and 56

serve a dual purpose for plant operations as criticality and fuel handling accident sensors. Although these monitors are designed primarily to detect fuel handling accident releases, they are capable of detecting an inadvertent criticality incident. The Setpoint given in the requirement is established for the fuel handling building isolation function but is also adequate for an inadvertent criticality.

BYRON - UNITS 1 & 2 B 3/4 3-3

INSTRUMENTATION

. i BASES _

3/4.3.3.2 MdVABLE INCORE DETECTOPS 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 measuringnF (Z) or Fh a full incore flux map is used.

, Quarter-core flux maps, as defined in WCAP-8648, June 1976, may be used in 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.

3/4.3.3.3 SEISMIC INSTRUMENTATION The OPERABILITY of the seismic instrumentation ensures that sufficient capability is available to promptly determine the magnitude of a seismic event and evaluate the response of those features important to safety. This capability is required to permit comparison of the measured response to that used in the design basis for the facility to detertnine if plant shutdown is required pursuant to Appendix A of 10 CFR Part 100.

The instrumentation consists of two time-history response spectrum analyzers,

, a playback unit, three peak recording accelerometers, and six triaxial acceler-ometers. One time-history recorder and one sensor are located down at the River Screen House. The rest of the equipment, excluding the sensors, is located in the Auxiliary Electrical Room. The remaining sensors are located as follows:

three in containment, one in the Auxiliary Building, and one at the free field location 27 + 00N, 41 + ODE. The peak recording accelerometers are passive devices which have no interplay on the rest of the system and are located on reactor equipment, reactor piping, and outside containment on the Category I piping. .

The triaxial accelerometer is based on three orthogonal force-balanced servo-accelerometers which generate a voltage signal upon stimulation. The voltage signals are transmitted to the time-history recorder in the Auxiliary

, Electrical Room, digitized, and recordedmagnetic-tapex l l l The time-history recorder is the master control unit for all control timing signals and system data interface. It also contains the system triggers used to t.ctuate the system. The master control unit continus11y monitors two of the sensor inputs, which are processed through the trigger circuits for comparison to the system actuation level. The time-history recorder also has the ability to record both pre- and post-seismic event data. The other key component in the system is the response spectrum analyzer. This unit deter 1 nines the variation in the maximum response of a single-degroe-of-f reedom system system versus its natural frequency of vibration when either of two designated triaxial accelero-meters is subjected to a time-history mation of the accelerometer.

BYRON - UNITS 1 & 2 8 3/4 3-4

..- - - -.