ML20137P756
| ML20137P756 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 03/31/1997 |
| From: | PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | |
| Shared Package | |
| ML20137P755 | List: |
| References | |
| NUDOCS 9704090313 | |
| Download: ML20137P756 (18) | |
Text
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a. - -, a ATTACHMENT 1 PEACH BOTTOM ATOMIC POWER STATION UNITS 2 AND 3 Docket No. 50-277 50-278 License Nos. DPR-44 DPR-56 License Change Request ECR 96-00627
" Surveillance Requirements for APRM Flow Units and Associated Flow Transmitters" Supporting information for changes - 3 pages F
9704090313 970331 PDR ADOCK 0500o277 P
RPS Instrumentation B 3.3.1.1 BASES i
4 SURVEILLANCE' SR 3.3.1.1.13 (continued)
REQUIREMENTS-Valve Fast Closure, Trip 011 Pressure-Low Functions are considered inoperable. Alternatively, the bypass channel can be placed in the conservative condition-(nonbypass).. If 1
placed in the nonbypass condition, this SR is met and the channel is considered OPERABLE.
I The Frequency of 24 months is based on engineering judgment and reliability of the components.
SR 3.3.1.1.17 i
The LOGIC SYSTEM FUNCTIONAL TEST demonstrates the l
OPERABILITY of the required trip logic for a specific.
channel. The functional testing of control rods (LCO 3.1.3), and SDV vent and drain valves (LCO 3.1.8),
overlaps this Surveillance to provide complete. testing of the assumed safety function.
The 24 month Frequency is based on the need to perfom this Surveillance under the conditions that apply during a plant outage and the potential' for an unplanned transient if the Surveillance were performed with the reactor at power.
Operating experience has shown that these components will pass the Surveillance when perfomed at the 24 month j
Frequency.
SR 3.3.1.1.18 i
This SR ensures that the individual channel response times are maintained less than or equal to the original design L
value. The RPS RESPONSE TIME acceptance criterion is included in Reference 11.
RPS RESPONSE TIME tests are'cenducted on a 24 month Frequency. The 24 month Frequency is consistent with the PBAPS refueling cycle and is based upon plant operating experience, which shows that random failures of instrumentation components causing serious responn time j
degradation, but not channel failure, are infrequent occurrences "A
(
(continued)
.PBAPS UNIT 3 B 3.3-35 Revision No. 3 i
1 l
RPS Instrumentaticn 1
B 3.3.1.1 i
BASES SURVEILLANCE SR 3.3.1.1.9 and SR 3.3.1.1.14 (continued) l REQUIREMENTS The 24 month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the i
Surveillance were performed with the reactor at power.
Operating experience has shown that these components will j
pass the Surveillance when performed at the 24 month j
Frequency.
SR 3.3.1.1.10. GR 3.3.1.1.11. SR 3.3.1.1.12.
SR 3.3.1.1.15. and SR 3.3.1.1.16
)
i i
4 A CHANNEL CALIBRATION is a complete check of the instrument l
-loop and the sensor. This test verifies that the channel
)
responds to the measured parameter within the necessary range and accuracy. CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drifts between successive calibrations, consistent with the current plant specific setroint methodology. SR 3.3.1.1.16, however, is only a calibration of the radiation detectors using a standard radiation source.
j As noted for SR 3.3.1.1.11 and SR 3.3.1.1.12, neutron 4
detectors are excluded from CHANNEL CALIBRATION because they i
are passive devices, with minimal drift, and because of the difficulty of simulating a meaningful signal. Changes in neutron detector sensitivity are suspensated for by performing the 7 day calorimetric calibration (SR 3.3.1.1.2) and the 1000 MWD /T LPRM calibration against the TIPS (SR3.3.1.1.8). A second note is provided for i
SRs 3.3.1.1.11 and 3.3.1.1.12 that allows the APRM and IRM SRs to be performed within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> of entering MODE 2 from i
MODE 1.
Testing of the MODE 2 APRM and IRM Functions cannot be performed in MODE 1 without utilizing jumpers, lifted leads or movable links. This Note allows entry into MODE 2 i
-from MODE 1, if the 184 day or 18 month Frequency is not met per SR 3.0.2.
Twelve hours is based on operating experience and in consideration of providing a reasonable time in which to complete the SR. As noted for SR 3.3.1.1.10, radiation 2
(continued)
A +biral no+e. is provided Cr SR 3. 3.1. l.12 4ka+ ee c,lude s de, APRM Clow us+s and a s saceed Flow + mns m1 +-lers %m 4;s SR sinee,
+he. c.u l: bm+ ion reguira mun+
he
+hsse.
- n sf ru ene.n+s is sp c@ie.cl
- n SR 3.3.1.l. 69.
PBAPS UNIT 3 B 3.3-33 Revision No. 1 A
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RPS Instrumentatien 3.3.1.1
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Table 3.3.1.1 1 (page 1 of 3)
Reester Protection system Instrumentation i
ame APPLICRSLE EXIWIficus NSEs et PseJISS REFERENCED l
wmR Camsa8 Fem WECIFIOD PER TRIP RERJIRED REVEILLANCE minua4LE FlalCTION COWITIthJs STsfat ACTION D.1 REGUIREM NTS VALAE i
1.
I#vterendlete Renes mentters e.
Neutron FLw -alsh 2
3 e
st 3.3.1.1.1 s 120/125 st 3.3.1.1.3 divistens of i
st 3.3.1.1.5 futi scate-st 3.3.1.1.6 SR 3.3.1.1.11 SR 3.3.1.1.17 SR 3.3.1.1.18 5(e) 3 N
st 3.3.1.1.1 s 120/'.3 sa 3.3.1.1.4 divleiens of 3R 3.1.1.1.11 full acele,
SR 3.11.1.17 st 3.3.1.1.18 b.
Insp 2
3 e
at 3.3.1.1.3 mA st 3.3.1.1.17 5(e) 3 N
st 3.3.1.1.4 NA SR 3.3.1.1.17 2.
Averess Power Range i
Monitors e.
Start y Nish Fitet 2
2 s
at 3.3.1.1.1 s 15.05 RTP seren sa 3.3.1.1.3 sa 3.3.1.1.6 sa 3.3.1.1.s i
sa 3.3.1.1.12 st 3.3.1.1.17 SR 3.3.1.1.18 b.
Flow sleoed Nish 1
2 F
SR 3.3.1.1.1 s 0.66 W Ib) scree SR 3.3.1.1.2
+ 63.9E RTP st 3.3.1.1.7 st 3.3.1.1.8 6 R. 3 3.1. I 8 't E!:!:I:l:I2 st 3.3.1.1.17 st 3.3.1.1.18 c.
seren Cleg 1
2 F
st 3.3.1.1.1 s 118.01 RTP st 3.3.1.1.2 st 3.3.1.1.8 st 3.3.1.1.9 sa 3.3.1.1.12 BR 3.3.1.1.17 st 3.3.1.1.18 d.
Deunecele 1
2 F
st 3.3.1.1.8 t 2.5E RTP j
at 3.3.1.1.9 st 3.3.1.1.17 e.
Inap 1,2 2
a st 3.3.1.1.8 NA st 3.3.1.1.9 SR 3.3.1.1.17 (continued)
(e) With any centrol red withdrom free e core cett centelnins one er more fuel assemblies.
(b) 0.66 W + 63.9E 0.66 AW RTP then reset for single leap operation per Lto 3.4.1, "Recirculotten Leops Operatire."
2 PBAPS UNIT 3 3.3-7 Amendment No. 214
i l
RPS Instrumentaticn 3.3.1.1 l
SURVEILLANCE REQUIRENENTS (continued)
SURVEILLANCE FREQUENCY SR 3.3.1.1.14 Perform CHANNEL FUNCTIONAL TEST.
24 months I
SR 3.3.1.1.15 Perform CHANNEL CALIBRATION.
24 months 1
SR 3.3.1.1.16 Calibrate each radiation detector.
24 months SR 3.3.1.1.17 Perform LOGIC SYSTEM FUNCTIONAL TEST.
24 months SR 3.3.1.1.18 Verify the RPS RESPONSE TINE is within 24 meaths limits.
i m.
SR 3.3.1. t. l ci Calbf e, APRM plu usNs ancJ 2,4 rnonfh3 a sse cta4e.cl flow + ran s mi +4 e.ca.
t i
4 PBAPS UNIT 3 3.3-6 Amendment No. 214
RPS Instrumentaticn 3.3.1.1 j
SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY SR 3.3.1.1.9 Perform CHANNEL FUNCTIONAL TEST.
92 days i
i j
SR 3.3.1.1.10
NOTE-------------------
Radiation detectors are excluded.
i j
l Perform CHANNEL CALIBRATION.
92 days SR 3.3.1.1.11
NOTES------------------
'l 2
1.
Neutron detectors are excluded.
j 2.
Not required to be perfomed when
)
entering MODE 2 from MODE 1 until i
12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after entering MODE 2.
l Perfom CHANNEL CALIBRATION.
184 days SR 3.3.1.1.12
NOTES------------------
1.
Neutron detectors are excluded.
2.
For Function 2.a. not required to be performed when entering MODE 2 from
- 3. APRM flow MODE 1 until 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after entering u R5 and W.. MODE 2.
a.,,. c; a+ ed
$lo w wu,3 3,,,a ter, Perform CHANNEL CALIBRATION.
18 months arc <.tc, luted SR 3.3.1.1.13 Verify Turbine Stop Valve-Closure 'and 24 months lurbine Control Valve Fast Closure, Trip 011 Pressure-Low Functions are not bypassed when THERMAL POWER is a: 30% RTP.
i (continued)
PBAPS UNIT 3 3.3-5 Amendment No. 214 i
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.o SR 3.3.1.1;19 The Average Power Range Monitor Flow Biased High Scram Function uses the recirculat. ion loop drive flows to vary the trip setpoint.i This SR ensures that the flow unit instrumentation that supplies the recirculation flow signal to the' APRM system responds to the measured recirculation flow within the necessary range and accuracy by use of a standard pressure source.. CHANNEL CAllBRATION ieaves the channel adjusted to account for instrument drifts between successive calibrations.
The Frequency of 24 ' months is based on the need to perform this Surveillance under the conditions that apply during 'a plant outage and the potential for an i
unplanned transient if the Surveillance were performed with the reactor at power.
Operating expedence has shown that these components will pass the Surseillance when performed at the 24 month Frequency.
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RPS Instrumentaticn B 3.3.1.1 l
BASES i
SURVEILLANCE SR 3.3.1.1.18 REQUIREMENTS (continued)
This SR ensures that the individual channel response times are maintained less than or equal to the original desigt, value. The RPS RESPONSE TIME acceptance criterion is included in Reference 11.
RPS RESPONSE TIME tests are conducted on a 24 month i
Frequency. The 24 month Frequency is consistent with the PBAPS refueling cycle and is based upon plant operating experience, which shows that random failures of
.f n;ef t instrumentation components causing serious response time degradation, but not channel failure, are infrequent o
Te d n A occerrences.
REFERENCES 1.
UFSAR, Section 7.2.
2.
UFSAR, Section Chapter 14.
3.
NEDO-23842, " Continuous Control Rod Withdrawai in the Startup Range," April 18, 1978.
4.
NEDC-32183P, " Power Rerate Safety Analysis Report for Peach Bottom 2 & 3," dated May 1993.
5.
UFSAR, Section 14.6.2.
6.
UFSAR, Section 14.5.4.
7.
UFSAR, Section 14.5.1.
8.
P. Check (NRC) letter to G. Lainas (NRC), "BWR Scram Discharge System Safety Evaluation," December 1,1980.
9.
NED0-30851-P-A, " Technical Specification Improvement Analyses for BWR Reactor Protection Systes,"
March 1988.
10.
MDE-87-0485-1, " Technical Specification Improvement Analysis for the Reactor Protection System for Peach Botton Atomic Power Station Units 2 and 3," October 1987.
11.
UFSAR, Section 7.2.3.9.
PBAPS UNIT 2 B 3.3-35 Revision No. 1
.~
RPS Instrumentation B 3.3.1.1 j
BASES SURVEILLANCE SR 3.3.1.1.10. SR 3.3.1.1.11. SR 3.3.1.1.12.
REQUIREMENTS SR 3.3.1.1.15. and SR 3.3.1.1.16 (continued) are passive devices, with minimal drift, and because of the difficulty of simulating a meaningful signal.
Changes in neutron detector sensitivity are compensated for by r
perfoming the 7 day calorimetric calibration (SR 3.3.1.1.2)and the 1000 MWD /T LPRM calibration against the TIPS (SR 3.3.1.1.8).
A second note is provided for a
SRs 3.3.1.1.11 and 3.3.1.1.12 that allows the APRM and IRM SRs to be performed within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> of entering MODE 2 from MODE 1.
Testing of the MODE 2 APRh and IRM Functions cannot i
be performed in MODE 1 without utilizing jumpers, lifted leads or movable links. This Note allows entry into MODE 2 from MODE 1, if the 184 day or 18 month Frequency is not met i
per SR 3.0.2.
Twelve hours is based on operating experience l
and in consideration of providing a reasonable time in which i
j to complete the SR. A third note is provided for SR 3_.3.1.1.12 that s Ine APRM SR to be perfo out fentering the associat nditions an ed Actions for
[up to six hours provided s maintained at or above 82% where the AP setpoin asas clamped.
Once 1
core flow d low 82%, and the APRM se oints bec biased, associated Conditions and Reau i
ns must be entered.f As noted for SR 3.3.1.1.10, t
radiation detectors are excluded from CHANNEL CALIBRATION due to ALARA reasons (when the plant is operating, the u clAs +be, APRio radiation detectors are generally in a high radiation area; U * "".Y S "g the steam tunnel; This exclusion is acceptable because the radiation detectors are passive devices, with minimal drift.
a.n o cis h d Ela w The radiation detectors are calibrated in accordance with l
+ mn g m; ++e rs Am SR 3.3.1.1.16 on a 24 month Frequency.
g,;s S R.3inc.c the The 92 day Frequency of SR 3.3.1.1.10 is conservative with ye'*4 respect to the magnitude of equipment drift assumed in the cali b ra+..on setpoint analysis. The Frequencies of SR 3.3.1.1.11 and h : p,r +We inshmeds SR 3.3.1.1.12 are based upon the assumption of a 184 day or
/
an 18 month calibration interval, respectively, in the d b 5,'"
. )
13 sP determination of the magnitude of equipment drift in the S R. 3*3.1 I
- icl, setpoint analysis.
The Frequencies of SR 3.3.1.1.15 and L
j i
SR 3.3.1.1.16 are based upon the assumption of a 24 month l
calibration interval in the determination of the magnitude j
of equipment drift in the applicable setpoint analysis.
J (continued) l PBAPS UNIT 2 B 3.3-33 Revision No.
l Amendment No. 216 i
1
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RPS Instrtmentation 3.3.1.1
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Table 3.3.1.1 1 (gese 1 of 3)
Reactor ProtectlJn System Instrissentation i
i APPLICABLE CouDITIous NSEs W R$EllEED REFEREhCED OTIER CNAINELs PAM sPECIFIED PER TRIP REGUIRED REVEILLANCE ALLindh8LE FUNCTION CouDITIONS HsTBI ACTION D.1 ReeUIAGENTS VALUE 1.
Intermediate aanse Monitors a.
Neutron Flux -Hish 2
3 s
at 3.3.1.1.1 5 120/125 sa 3.3.1.1.3 divielens of t
at 3.3.1.1.5 full eseLe sa 3.3.1.1.6 sa 3.3.1.1.11
-i sa 3.3.1.1.17 sa 3.3.1.1.18 5(e) 3 N
sa 3.3.1.1.1 s 120/125 st 3.3.1.1.4 divialens of sa 3.3.1.1.11 futt scale 1
sa 3.3.1.1.17 1
sa 3.3.1.1.18 b.
Inop 2
3 s
sa 3.3.1.1.3 mA i
sa 3.3.1.1.17 l
5(s) 3
,, 3,3,3,3,4
,g 4
sa 3.3.1.1.17 2.
Average Power Range Monitors a.
Starte Nigh Flux 2
2 s
sa 3.3.1.1.1 s 15.01 RTP e
1 Scram sa 3.3.1.1.3 st 3.3.1.1.6 i
sa 3.3.1.1.8 1
sa 3.3.1.1.12 SR 3.3.1.1.17 st 3.3.1.1.18 b.
Flow Blased High 1
2 F
sa 3.3.1.1.1 s 0.66 W Scram sa 3.3.1.1.2
+ 63.9E RTP(b) sa 3.3.1.1.7 sa 3.3.1.1.8 st 3.3.1.1.9 SR 3.3. i.l. R sR 3.3.1.1.12 SR 3.3.1.1.17 sa 3.3.1.1.18 c.
Scram Clag 1
2 F
sR 3.3.1.1.1 5 118.05 RTP sa 3.3.1.1.2 sa 3.3.1.1.8 SR 3.3.1.1.9 i
at 3.3.1.1.12 st 3.3.1.1.17 sa 3.3.1.1.18 d.
Downscale 1
2 F
st 3.3.1.1.8 2 2.55 RTP 3R 3.3.1.1.9 sa 3.3.1.1.17 t
e.
Inap 1,2 2
s at 3.3.1.1.8 mA sa 3.3.1.1.9 4
st 3.3.1.1.17 i
r (continur' (a) With any control rod withdraun from a core cett containing one or more fuel assembtles.
L (b) 0.66 W + 63.9%
- 0.66 AW RTP adien reset for single loop operation per LCD 3.4.1, " Recirculation Loops operatins."
PBAPS UNIT 2 3.3-7 Amendment No. 210
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RPS Instrumentati(En 3.3.1.1 SURVEILLANCE REQUIREMENTS (continued)
SURVEILLANCE FREQUENCY 24 months SR 3.3.1.1.13 Verify _. Turbine Stop Valve-Closure and l
Turbine Control Valve Fast Closure, Trip 011 Pressure-Low Functions are not bypassed when THERMAL POWER is := 30% RTP.
24 months SR 3.3.1.1.14 Perform CHANNEL FUNCTIONAL TEST.
SR 3.3.1.1.15 Perform CHANNEL CALIBRATION.
24 months SR 3.3.1.1.16 Calibrate each radiation detector.
24 months SR 3.3.1.1.17 Perform LOGIC SYSTEM FUNCTIONAL TEST.
74 months SR 3.3.1.1.18 Verify the RPS RESPONSE TINE is within 24 months limits.
i
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~
SR. 3.3.1. t.19 Calibra+e, APRM Slow udfs and assocta hl flow f ransm:++ e.rs.
1 i
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FBAPS UNIT 2 3.3-6 Amendment No.2IO, 216
RPS Instrumentation 3.3.1.1 i
SURVEILLANCE REQUIRENENTS (continued)
SURVEILLANCE FREQUENCY SR 3.3.1.1,9 Perform CHANNEL FUNCTIONAL TEST.
92 days SR 3.3.1.1.10
NOTE-------------------
Radiation detectors are excluded.
Perform CHANNEL CALIBRATION.
92 days SR 3.3.1.1.11
NOTES------------------
1.
Neutron detectors are excluded.
2.
Not required to be performed when entering MODE 2 from MODE 1 until 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after entering MODE 2.
Perform CHANNEL CALIBRATION.
184 days SR 3.3.1.1.12
NOTES------------------
i 1.
Neutron detectors are excluded.
2.
For Function 2.a not required to be performed when entering MODE 2 from MODE 1 until 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after entering MODE 2.
3.
(P nction 2.b, until complet p f ref tage 2R11, entry ipte APR M flow associa nditions # Required gg Actions may
~(layid for up to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> provided-tof low is a55ccicded maintair. edit or above This is St.w
! an excijition to Surveillan
+rans mM+ws (Re6uirements Note 2 f L m acWJ.
Perform CHANNEL CALIBRATION.
18 months (continued)
PBAPS UNIT 2 3.3-5 Amendment No. 2IO, 216
ATTACHMENT 2 PEACH BOTTOM ATOMIC POWER STATION UNITS 2 AND 3 Docket Nos. 50-277 50-278 License Nos. DPR-44 DPR-56 License Change Request ECR 96-00627 i
List of Attached Pages i
.V. Gill Unit 3 3.3-5 3.3-5 3.34 3.34 3.3-7 3.3-7 B3.3-33 B3.3-33 B3.3-35 B3.3-35 m.
Docket Nos. 50-277 50-278 Ucense Nos. DPR-44 DPR-56
- 0 APRM system provides monitoring and accident mitigation functions to limit peak
- flux in the core during Modes 1 and 2. No pressure boundary interfaces or process control parameters will be challenged in any way as to create the possibility of a new or different type of accident than any previously evaluated.
Also, failure of the sensing line associated with flow transmitters to measure recirculation drive flow has already been accounted for in the initial plant design by includmg excess flow check valves for sensing line break isolation.
Therefore, these changes will not create the possibility of a new or different kind of accident from any accident previously evaluated.
lii)
The orooosed changes do not involve a sianificant reduction in a marain of g[gty because the APRM flow biased high flux scram is not credited in the
' PBAPS safety analysis. Because the proposed changes do not impact safety analysis assumptions, these proposed changes will not involve a significant reduction in a margin of safety.
Information Sucoortina an Environmental Assessment An environmental impact assessment is not required for the changes proposed by this appik:stion because the changes conform to the criteria for " actions eligible for categorical exclusion," as provided for under 10CFR51.22(c)(9). The requested changes will have no impact on the environment. The proposed changes do not involve a Significant Hazards Consideration as discussed in the preceding section.
The proposed changes do not involve a significant change in the types or significant i
increase in the amounts of any effluents that may be released offsite. The proposed i
changes do not authorize any change in the authorized power level of the facility. In addition, the proposed changes do not involvo a significant increase in individual or cumulative occupation radiation exposure.
Conclusion The Plant Operation Review Committee and the Nuclear Review Board have reviewed i
the proposed changes to the TS and have concluded that the changes do not involve an unroviewed safety question and will not endanger the public health and safety.
)
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i Docket Nos. 50-277 50 278 License Nos. DPR-44 DPR-56 Changes are proposed to TSSR 3.3.1.1.12 and TS Table 3.3.1.1-1 and a new TSSR 3.3.1.1.19 is proposed to allow calibration of the APRM flow bias instrumentation during an outage and avoid the risk of a scram associated with on-line calibration. Associated Bases changes are also proposed.
i 3
Safety Assessment i
The APRM flow biased high flux scram is not credited in the PBAPS safety analysis.
The design basis for the APRM flow bias scram is toprovide additional margin to the clamped high flux scram setpoint.
I
' implementation of the proposed TS changes will not impact the function of the APRM
-flow bias instrumentation. The new hardware employed in the APRM flow bias i
- instrumentation has the documented performance characteristics necessary to
)
accurately perform its design function on a 24 month calibration interval. The 24 month calibration interval would match the 24 month operating cycle. The calibrations i
can then be done between operating cycles and avoid the risk of an unnecessary scram.
I informatien Suooortina a Findina of No Sianificant Hazards Consideration The changes proposed in this application do not constitute a Significant Hazards consideration in that:
i)
The orooosed chanaes do not involve a sianificant increase in the probability or
)
consecuences of an accident previously evaluated because the accidents previousiy evaluated take credit only for the clamped 120% high neutron flux scram setpoint. Credit is not taken for the flow biased APRM scram setpoint.
Failure or inaccuracy of the flow biased feature of the APRM scram setpoint will in no way affect the clamped high flux scram setpoint. The 120% high flux scram j
setpoint is derived internal to the APRM circuitry and calibrated separately as part of the APRM trip circuitry. The APRM clamped high flux scram setpoint is not being impacted by the' proposed changes and will be automatically enforced regardless of the status or accuracy of the APRM flow bias circuitry.
Because there is no impact on the clamped 120% high neutron flux scram setpoint which is the only APRM scram setpoint with any analytical safety basis, the proposed changes will not involve a significant increase in the probability or consequences gf an accident previously evaluated.
i I
li)
The orooosed chanaes do not creets the possibility of a new or different kind of accident from any accident previousiv evaluated because the proposed changes c
. do not allow plant operation in any mode that is not already evaluated. The m
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_ _ _ _ _ ~ _ _
Docket Nos. 50-277 50-278 License Nos. DPR 44
~
DPR-56 i
PECO Energy Company (PECO Energy) requests that the Technical Specifications (TS) for the Peach Bottom Atomic Power Station (PBAPS) Units 2 and 3, be amended 1
as proposed below for extending the surveillance interval for calibration of Average Power Range Monitor (APRM) flow bias instrumentation from 18 months to 24 months.
l Provided below is a discussion and description of the proposed changes, a safety 1
assessment, information supporting a finding of No Significant Hazards Consideration, and information supporting an Environmental Assessment.
The marked-up pages indicating the proposed changes are provided in Attachment 2.
We request that, if approved, the changes be effective by August 17,1997. This date is the last day thrit the frequency for TS Surveillance Requirement (SR) 3.3.1.1.12 is met in accordance with TSSR 3.0.2 as measured from the previous performance.
Discussion and Descriotion of the Proposed Chanaes Calibration of APRM flow bias instrumentation is governed by TSSR 3.3.1.1.12. The frequency is specified as every 18 months. Because PBAPS utilizes 24 month operating cycles between refuelings, TSSR 3.3.1.1.12 is required to be performed on line. Performance of APRM flow bias instrumentation calibration on-line causes one complete division of APRMs to be inoperable during the course of the surveillance which is nominally four to six hours per division. This condition causes entry into TS Condition 3.3.1.1C which requires that Reactor Protection System (RPS) trip capability l
be restored within one hour. In order to restore RPS trip capability for the flow bias instrumentation, the ARM division undergoing test must be placed in a tripped condition which results in a half scram. Having the plant in a half scram condition for this period
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of time is undesirable due to the risk of perturbations on the opposite RPS channel causing a full scram that challenges equipment and operations personnel.
The APRM safety design basis does not require the flow biasing signal to fulfill it purpose. Furthermore, the Updated Final Safety Analysis Report accident and transient analyses do not nke credit for the flow bias function in the mitigation of any accidents or transients.
The APRM flow bias instrumentation has recently been upgraded. The original equipment has been replaced with new equipment that exhibits performance characteristics that enable it to operate for 24 months between calibration checks. The assessment is based on actual 24 month calibration interval results; therefore, no extrapolation of data is necessary. This assessment is based on a review of PBAPS historical,24 month interval calibration data of components identical to, or from the same component line, as that used in the flow bias instrumentation design. The review showed all as-found data to be within limits without any need for recalibration.
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ATTACHMENT 1 PEACH BOTTOM ATOMIC POWER STATION UNITS 2 AND 3 Docket No. 50-277 50-278 6
License Nos. DPR-44 4
DPR-56 6
License Change Request i
ECR 96-00627 i
" Surveillance Requirements for APRM Flow Units and Associated Flow Transmitters" Supporting information for changes - 3 pages e
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SR 3.3.1.1.19 The Average Power Range Monitor Flow Biased High Scram Function uses the recirculation loop drive flows to vary the trip setpoint; This SR ensures that the flow unit instrumentation that supplies the recirculation flow signal to the APRM system responds to the measured recirculation flow within the necessary range j
and accuracy by use of a standard pressure source. CHANNEL CALIBRATION leaves the channel adjusted to account for instrument drifts between successive 1
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calibrations.
The Frequency of 24 months. is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an 4
l unplanned transient if the Surveillance were performed with the reactor at power.
' Operating experience has shown that these components will pass the Surveillance when performed at the 24 month Frequency.
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