ML20141A800
| ML20141A800 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 05/08/1997 |
| From: | ENTERGY OPERATIONS, INC. |
| To: | |
| Shared Package | |
| ML20141A798 | List: |
| References | |
| NUDOCS 9705150015 | |
| Download: ML20141A800 (3) | |
Text
.~.
. - ~ -
~.
d
-3/4.3 INSTRUMENTATION f.
BASES' l
3/4.3.1 and 3/4.3.2 PROTECTIVE AND ENGINEERED SAFETY FEATURES (ESP)
INSTRUMENTATION i
The OPERABILITY of the protective and ESF instrumentation systems and bypasses ensure that 1) the associated ESF action and/or reactor trip will be initiated when the parameter monitored by each channel or combination thereof reaches its setpoint, 2) the specified coincidence logic is
~
maintained, 3). sufficient redundancy is maintained to permit a channel to be j
-out of-service for testing or maintenance,' and 4) sufficient system functional capability is available for protective and ESF purposes from diverse parameters, j
The OPERABILITY of these systems is required to provide the overall reliability, redundancy and diversity assumed available in the facility design for the protection and mitigation of accident and transient conditions. _The integrated operation of each of these systens is consistent with the assumptions used in the accident analyses.
The surveillance requirements specified for these systems ensure that j
the overall system functional capability is maintained comparable to the j
original design standards. The periodic surveillance tests performed at the minimum frequencies are sufficient to demonstrate this capability. The triannual channel functional testing frequency is to be performed on a j
j STAGGERED TEST BASIS.
The measurement of response time at the specified frequencies provides assurance that the protective and ESF action function associated with each channel is completed within the time limit assumed in the accident analyses.
j No credit was taken in the analyses for those channels with response times indicated as not applicable, i
t Response time may be demonstrated by any series of sequential, l
overlapping or total channel test measurementa provided that such testa j
t demonstrate the total channel response time as defined.
Sensor response time verification may be demonstrated by either 1) in place, onsite or offsite test measurements or 2) utilizing replacement sensors with certified response times.
RTD response time is defined as the time interval required for the RTD output to achieve 63.2% of its total change when subjected to a step change in RTD temperature. The RTD response time for the Core Protection Calculator System (CPCS) is expressed as an effective time constant.
For hot leg temperatures, the effective time constant for a given CPC channel is defined l
as the mean time constant for averaged pairs of hot leg RTD inputs to the channel. This is done because the CPCS utilizes the mean hot leg temperature in its calculations. The maximum hot leg effective time constant allowable for use in the CPCS is 13.0 seconds.
For cold leg temperatures, the effective time constant to be used in Figure 3.3-1 is the maximum time constant of the two cold leg RTD inputs for a given channel. The CPCS utilizes the more i
conservative cold leg temperature in the various DNBR and LPD calculations.
3 The maximum cold leg effective time constant allowable for use in the CPCS is 13.0 seconds.
t l
i 970515KX)15 9705C6 PDR ADOCK 05000368 P
PEWt j
1 l
ARKANSAS'- UNIT 2.
B 3/4 3-1 Amendment No. 46,79, 4
a
O e
MABKUP OF CURRENT ANO-2 TECHNICAL SPECIFICATION BASEE (FOR INFO ONLY) 4 l
I
]
l 3/4.3 INSTRUMENTATION i
BASES i
3/4.3.1 and 3/4.3.2 PROTECTIVE AND ENGINEERED SAFETY FEATURES (ESP) i INSTRUMENTATION The OPERABILITY of the protective and ESF instrumentation systems and bypasses ensure that 1) the associated ESF action and/or reactor trip will i
be initiated when the parameter monitored by each channel or combination j
thereof reaches its setpoint, 2) the specified coincidence logic is maintained, 3) sufficient redundancy is maintained to permit a channel to be out of service for testing or maintenance, and 4) sufficient system functional capability is available for protective and ESF purposes from diverse parameters.
The OPERABILITY of these systems is required to provide the overall reliability, redundancy and diversity assumed available in the facility 1
design for the protection and mitigation of accident and transient conditions. The integrated operation of each of these systems is consistent with the assumptions used in the accident analyses.
The surveillance requirements specified for these systens ensure that the overall system functional capability is maintained comparable to the original design standards. The periodic surv6tilanca tests performed at the minimum frequencies are sufficient to demonstrate this capability.
The triannual-channel functional testino frecuency is to_ be Derformed on a STAGGERED TESI BASIS.
Thi; te; tin ;;t r.ij;10 7 i; b ::d ;n th: relieb' lit, On:lv;i: :::::nted
[n t;;1;;l r;;; t C5 "PSO 575. "PPS/ESF?.S Eg, tend:j T::t Interval Ev:lu;ti:n F::
}20 0;^. !;;;;;.;d T : tin;".
+
The measurement of response time at the specified frequencies provides assurance that the protective and ESF action function associated with each channel is completed within the time limit assumed in the accident analyses.
No credit was taken in the analyses for those channels with response times indicated as not applicable.
i Response time may be demonstrated by any series of sequential, overlapping or total channel test measurements provided that such tests demonstrate the total channel response time as defined.
Sensor response time verification may be demonstrated by either 1) in place, onsite or t
offsite test measurements or 2) utilizing replacement sensors with certified response times.
l RTD response time is defined as the time interval required for the RTD i
output to achieve 63.2% of its total change when subjected to a step change In RTD temperature. The RTD response time for the Core Protection Calculator System (CPCS) is expressed as an effective time constant.
For hot leg temperatures, the effective time constant for a given CPC channel is defined as the mean time constant for averaged pairs of hot leg RTD inputs to the channel. This is done because the CPCS utilizes the mean hot leg temperature in its calculations. The maximum hot leg effective time constant allowable I
for use in the CPCS is 13.0 seconds.
For cold leg temperatures, the effective i
time constant to be used in Figure 3.3-1 is the maximum time constant of the two cold leg RTD inputs for a given channel. The CPCS utilizes the more conservative cold leg temperature in the various DNBR and LPD calculations.
The maximum cold leg effective time constant allowable for use in the CPCS i
is 13.0 seconds.
ARKANSAS - UNIT 2 B 3/4 3-1 Amendment No. 33,79,
)
. ~
_ _ _ _.