ML20126J085

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Proposed Tech Specs 3.2.1 & 3.2.4,increasing Action Time from 1 H to 4 H When COLSS Out of Svc
ML20126J085
Person / Time
Site: San Onofre  Southern California Edison icon.png
Issue date: 12/31/1992
From:
SOUTHERN CALIFORNIA EDISON CO.
To:
Shared Package
ML20126J030 List:
References
NUDOCS 9301060029
Download: ML20126J085 (15)
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Text

{{#Wiki_filter:- I ATTACHMENT A-- EXISTING. TECHNICAL. SPECIFICATIONS AND BASES - UNIT 2 7 9302060029~921231' 

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3/4.2 POWER DISTRIBUTION LIMITS 3/4.2.1'tINEAR HEAT RATE LIMITING CONDITION FOR OPERATION 3.2.1 The linear heat rate shall not exceed 13.9 kw/ft. . APPLICABILITY: MODE 1 above 20% of RATED THERMAL POWER. ACTION: With the linear heat rate exceeding its limits, as indicated by either (1) the COLSS calculated core power exceeding the COLSS calculated core power operating limit based on kw/ft; or (2) when the COLSS is not being used, any OPERABLE Local Power Density channel exceeding the linear beat rate limit, within 15 minutes initiate corrective action to reduce the linear heat rate to within the limits and either:

a. Restore the linear heat rate to within its limits within one hour,.

or

b. Be in at least HOT STANDBY within the next 6 hours.

SURVEILLANCE REQUIREMENTS 4.2.1.1 The provisions of Specification 4.0.4 are not applicable. 4.2.1.2 The linear heat rate shall be determined to be within its limits when THERMAL POWER is above 20% of RATED THERMAL POWER by continuously monitoring the core power distribution with the Core Operating Limit Supervisory System (COLSS) or, with the COLSS out of service, by verifying at least once per 2 hours that the linear heat rate, as indicated on all OPERABLE Local Power Density channels, is within the limit of 13.9 kw/ft. 4.2.1.3 At least once per 31 days, the COLSS Margin Alarm.shall be verified to actuate at a THERHAL POWER level less than or equal to the core power operating limit based on kw/ft. SAN ONOFRE-UNIT 2 3/4 2-1 FEB13i BBT

POWER O!STRIBUTION LIMITS 3/4.2.41 0NBR MARGIN LIMITING CON 0! TION FOR OPERATION 3.2.4 The DNBR margin shall be maintained by one of following methods:

a. Maintaining COLSS calculated core power less than or equal to COLSS calculated core power operating limit based on DNBR (when COLSS is in service, and either one or both CEACs are operable); or
b. Maintaining COLSS cal ulated core power less than or equal to COLS$

calculated core power operating limit based on DNBR decreased by 13.0% RATED THERHAL POWER (when COLSS is in service and neither CEAC is operable): or

c. Operating within the region of acceptable operation of Figure 3.2-1 using any operable CPC channel (when COLSS is out of service and either one or both CEACs are operable); or ,

I

d. OperatingwithintheregionofacceptableoperationofFigure3.2-2usini l any operable CPC channel (when COLSS is out of service and neither CEACs is operable).

APPLICABILITY: H00E 1 above 20% of RATED THERMAL POWER. ACTION: t With the DNBR margin not being maintained, as indicated by: (1) COLSS calculated core power exceeding the appropriate COLSS calculated operating limit, or (2) Witn COLSS out of service, operatton outside the region of acceptable operation of Figure 3.2-1 or 3.2-2. Within 15 minutes initiate corrective action to restore the ONBR to within I its limits, and either:-

a. Restore the DNBR to within its limits within one hour, or
b. Be in at least HOT STANDBY within the next 6 hours.

SURVEILLANCE REQUIREMENTS 4.2.4.1 The provisions of Specification 4.0.4 are not applicable. 4.2.4.2 The DNBR shall be determined to be within its limits when THERHAL POWER is above 20% of RATED THERMAL POWER by continuously monitoring the core power distribution with the Core Operating Limit Supervisory System (COLSS) or, with the COLSS out of service, by verifying at least once per 2 hours that the ONBR, as indicated on any OPERABLE ONBR channel, is within the limit shown on Figures 3.2-1 or 3.2-2, as applicable. 4'.2.4.3' At least once per 31 days, the COLSS Margin Alarm shall be verified to actuate at a THERMAL POWER level less than or equal to the core power operating limit based on DNBR. 3/4 2-5 AMEN 0 MENT NO. 47 SAN ONOFRE-UNIT 2 

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1 3/4.2 POWER DISTRIBUTION LIMITS BASES 3[4.2.1 LINEAR HEAT RATE The limitation on linear heat rate ensures that in the event of a LOCA, the peak temperature of the fuel cladding will not exceed 2200*F. Either of the two core power distribution monitoring systems, the Core Operating Limit Supervisory System (COLSS) and the Local Power Density channels in the Core Protection Calculators (CPCs), provide adequate monitoring of the core power distribution and are capable of verifying that the linear heat rate does not exceed its its limits. The COLSS performs this function by continuously monitoring the core power distribution and calculating a core power operating limit corresponding to the allowable peak linear heat rate. Reactor operation at or below this calculated power level assures that the limits of 13.9 kw/ft are not exceeded. The COLSS calculated core power and the COLSS calculated core power operating limits based on linear heat rate are continuously monitored and  : displayed to the operator. A COLSS alarm is annunciated in the event that the core power exceeds the core power operating limit. This provides-adequate margin to the linear heat rate operating limit for normal. steady state opera-tion. Normal reactor power transients or equipment failures which do not require a reactor trip may result in this core power operating limit being exceeded. In the event this occurs, COLSS alarms will be annunciated. If.the event which causes the COLSS limit to be exceeded results in conditions which approach the core safety limits, a reactor trip will be initiated by the Reactor Protective Instrumentation. The COLSS calculation of the linear heat rate includes appropriate penalty factors which provide, with a 95/95 probability / confidence level, that the maximum linear heat rate calculated by COLSS is conservative with respect to the actual maximum linear heat rate existing in the' core. These penalty factors are determined from the uncer-tainties associated with planar radial peaking measurement, engineering design factors, axial densification, sof tware algorithm modelling, computer processing, rod bow and core power measurement. Parameters required to maintain the operating limit power level based on linear heat rate, margin to DNB and-total core power are also monitored by the-CPCs assuming minimum core power of 20% RATED THERHAL POWER. The 20% Rated Thermal Power threshold is due to the neutron flux detector system being inaccurate below 20% core power. Core noise level at low power is too large to obtain usable detector readings. Therefore, in the event that the COLSS is not being used, operation within the limits of Figure 3.2-2 can be maintained by utilizing a predetermined local power density margin and a total core power limit in the CPC trip channels. The above listed uncertainty penalty factors plus those associated with startup test acceptance criteria are also included in the CPCs. l- SAN ONOFRE-UNIT 2 B 3/4 2-1 l 'C:... i 682 

      ~

POWER DISTRIBUTION L1 HITS BASES DNBR Margi_n (Continued) The ONBR penalty f actors listed in section 4.2.4.4 are penalties used to accommodate the effects of rod bow. The amount of rod bow in each assembly is dependent upon the average burnup experienced by that assembly. fuel assemblies that incur higher average burnup will experience a greater magnitude of rod bow. Conversely, lower burnup assemblies will experience less rod bow. The penalty for each batch required to compensate for rod bow is determined from a batch's maximum average assembly burnup applied to the batch's maximum integrated planar-radial power peak. A single net penalty for COLSS and CPC is then determined from the penalties associated with each batch, accounting for the offsetting margins due to the lower radial power peaks in the higher burnup batches. 3/4.2.5 RCS FLOW RATE This specification is provided to ensure that the actual RCS total flow. rate is maintained at or above the minimum value used in the LOCA safety analyses. 3/4.2.6 REACTOR COOLANT COLD LEG TEMPERATURE This specification is provided to ensure that the actual value of reactor coolant cold leg temperature is maintained 'vithin the range of values used in the safety analyses. 2.4.2.7 AXIAL SHAPE INDEX The Axial Shape Index (ASI) is a measure of the power generated in the lower half of the core less the power generated in the upper half of the core divided by the sum of these powers. This specification is provided to ensure that the core average ASI is maintained within the range of values assumed as an initial condition in the safety analyses. This range is specified as 

        -0.3 1 ASI $ 0.3.

The ASI can be determined by utilizing either the Core Operating Limit Supervisory System (COLSS) or any operable Core Protection Calculator (CPC) channel. The real time monitoring capability and accuracy of COLSS allows COLSS to monitor power limit margins closely. Consequently, the ASI limit is broader than it would be with the same core without COLSS. The COLSS cen-tinuously calculates the ASI and compares the calculated value to the param-eter established for the COLSS ASI alarm limit. In addition, there is an uncertainty associated with the COLSS calculated ASl; therefore the COLSS ASI alarm limit includes this uncertainty. If the LCO is exceeded, COLSS alarms are initiated. The .31 safety setting is selected so that no safety limit will be exceeded as a result of an anticipated operational occurrence, and so I that the consequence of a design basis accident will be acceptable. l 1 SAN ONOFRE - UNIT 2 8 3/4 2-4 AMENDHENT NO. 62 

                                                                                                      \

l l POWER DISTRIBUTION LIMITS BASES AXIAL SHAPE INDEX (Continued) With COLSS out of service, any operable CPC channel may be used to calcu-late the ASI (using three axially spaced excore detectors). The axial shape synthesis in the CPC's shows the relative power produced as a function of core height in each third of the core. Due to the uncertainty associated with the CPC estimate, the ASI is restricted to a smaller range than the range cal-culated using the COLSS. The 20% rated thermal power threshold is imposed due to the inaccuracy of the neutron flux detector below the threshold. Core noise level is too large to obtain usable detector readings. 3/4.2.8 PRESSURIZER PRESSURE This specification is provided to ensure that the actual value of pressurizer pressure is maintained within the range of values used in the

  • safety analyses. .

SAN ONOFRE - UNIT 2 B 3/4.2-5 AMEN 0 MENT NO. 62

i l . i I a u ATTACHMENT B l EXISTING TECHNICAL SPECIFICATIONS  : AND BASES  ; UNIT 3 i e l r l i 

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3/4.*2. POWER OISTRIBUTION LIMITS 3/4.2.1 LINEAR HEAT RATE LIMITING CONDITION FOR OPERATION 3.2.1 The linear heat rate shall not exceed 13.9 kw/ft. APPLICABILITY: MODE 1 above 20% of RATED THERMAL POWER. ACTION: With the linear heat rate exceeding its limits, as indicated by either (1) the COLSS calculated core power exceeding the COLSS calculated core power operating limit based on-kw/f t; or (2) when the COLSS is not being used, any OPERABLE Local Power Density channel exceeding the linear _ heat rate limit, within 15 minutes initiate corrective action to reduce the linear heat rate to within the limits and either:

a. Re tore the linear heat rate to within its limits within one hour, or
b. Be in at least HOT STANDBY within the next 6 hours.

SURVEILLANCE REQUIREMENTS 4.2.1.1 The provisions of Specification 4.0.4 are not applicable. 4.2.1.2' The linear heat rate shall be determined to be within its limits when THERMAL POWER is above 20% of RATED THERMAL POWER by continuously monitoring the core power distribution with the Core Operating Limit Supervisory System (COLSS) or, with the COLSS out of service, by verifying at least once per 2 hours that the linear heat rate, as indicated on all OPERABLE Local Power Density channels, is within the limit of 13.9 kw/ft. 4.2.1.3 At least once per 31 days, the COLSS Margin Alarm shall be verified l to actuate at a THERMAL POWER level less than or equal to the core power l-operating limit based on kw/ft. l l l l NOV 151982 SAN ONOFRE-UNIT 3 3/4 2-1 __ ,- -. __ __ _ _ - . _ - . _ , s

~ POWER DISTRIBUT!0N LIMITS 3/4.2.4 DNBR MARGIN LlHITING CONDITION FOR OPERATION 3.2.4 The DNBR margin shall be maintained by one of following methods;

a. Maintaining COLS$ calculated core power less than or equal to COLSS l calculated core power operating limit based on DNBR (when COLSS is in service, and either one or both CEACs are operable,'; or I'
b. Maintaining COLSS calculated core power less than or equal to COLSS calculated core power operating limit based on DNBR decreased by .

13.0% RATED THERMA 1. POWER (when COLSS is in service and neither CEAC i is operable): or l

c. Operating within the region of acceptable operation of Figure 3.2-1 using ,

any operable CPC channel (when COLSS is out of service and either one or both CEACs are operable); or

d. Operating within the region of acceptable operation of Figure 3.2-2 usin'g' any operable CPC channel (when COLSS is out of service and neither CEACs is operable).

APPLICABILITY: H00E 1 above 20% of RATED THERMAL POWER. ACTION: With the DNBR margin not being maintained, as indicated by: (1) COLSS calculated core power exceeding the appropriate COLSS calculated operating limit, or (2) With COLSS out of service, operation outside the region of acceptable operation of Figure 3.2-1 or 3.2-2. Within 15 minutes initiate corrective action to restore the DNBR to within its limits, and either: ,

a. Restore the DNBR to within its limits within one hour, or
    #           b. Be in at least HOT STANOBY within the next 6 hours.

SURVEILLANCE REQUIREMENTS 4.2.4.1 The provisions of Specification 4.0.4 are not applicable. 4.2.4.2 The ONBR shall be determined to be within its limits when THERMAL POWER is above 20% of RATED THERMAL POWER by continuously monitoring the core power distribution with the Core Operating Limit Supervisory System (COLSS) or, with the COLSS out of service, by verifying at least once per 2 hours that the ONBR, as indicated on any OPERABLE ONBR channel, is wi+hin the limit shown on Figures 3.2-1 or 3.2-2, as applicable. , 4.2.4.3 At least once per 31 days, the COLS$ Margin Alarm shall be verified to actuate at a THERMAL POWER level less than or equal to the core power operating ~ limit based on DNBR. SAN ONOFRE-UNIT 3 3/4 2-5 AMENOMENT NO.36 

                                                                                         -]

1 t J l DELETED INTENTIONALLY I I SAN ONOFRE-UNIT:3 3/4 2-6 AMENDMENT-~NO. 36 _ = . , . , _

3/4. 2: POWER DISTRIBUTION LIMITS BASE 5 3/4.2.1 LINEAR HEAT RATE The limitation on linear heat rate ensures that in the event of a LOCA, the peak temperature of the fuel cladding will not exceed 2200*F. Either of the two core power distribution monitoring systems, the Core Operating Limit Supervisory System (COL 55) and the Local- Power Density channels in the Core Protection Calculators (CPCs), provide adequate monitoring of the core power distribution and are capable of verifying that the linear heat rate does not exceed its its limits The COLSS performs this function by continuously monitoring the core power distribution and calculating a core power operating limit corresponding to the allowable peak linear heat rate. Reactor operation at or below this calculated power level assures that the limits of 13.9 kw/ft are not exceeded. . The COLS5 calculated core power and the COL 55 calculated core power operating limits based on linear heat rate are continuously monitored and displayed to the operator. A COL 55 alarm is annunciated in the event that the core power exceeds the core power operating limit. This provides adequate margin to the linear heat rate operating limit for normal steady state opera-tion. Normal reactor power transients or equipment failures which do not require a reactor trip may result in this core power operating limit being l- exceeded. In the event this occurs, COLSS alarms will be annunciated. If the event which causes the COLS5 limit to be exceeded results in conditions whicn approach the core safety limits, a reactor trip will be initiated by the Reactor Protective Instrumentation. The COL 55 calculation of the linear heat rate includes appropriate penalty factors which provide, with a 95/95 probability / confidence level, that the maximum linear heat rate calculated by COL 55 is conservative with respect to the actual maximum linear heat rate existing in the core. These penalty factors are determined from the uncer-tainties associated with planar radial peaking measurement, engineering design factors, axial densification, software algorithm modelling, computer processing, ! rod bow and core power measurement. ) Parameters required to maintain the operating limit power level based on l linear heat' rate, margin to DNB and total core power are also monitored by the ! CPCs assuming minimum core power of 20% RATED THERMAL POWER. The 20% Rated Thermal Power threshold is due to the neutron flux detector system being-inaccurate below 20% core power. Core noise level at~ low power is too large to obtain usable detector readings. Therefore, in the event that the COL 55 is not being used, operation within the limits of Figure 3.2-2 can be maintained by utilizing a predetermined local power density margin and a total core power  ! limit in the CPC trip channels. The above listed racertainty penalty factors plus those associated with startup test acceptance criteria are also included in the CPCs. gy; i b 6E1 SAN ONOFRE-UNIT 3 B 3/4 2-1

4 POWER DISTRIBUTION L! HITS BASES ONBR Margin (Continued) A DNBR penalty factor has been included in the COLSS and CPC ONBR calculation to accommodate the effects of rod bow. The amount of rod bow in each assembly is dependent upon the average burnup experienced by that assembly. Fuel assemblies that incur higher average burnup will experience a greater magnitude of rod bow. Conversely, lower burnup assemblies will experience less rod bow. In design calculations, the penalty for each batch required to compensate for rod bow is determined from a batch's maximum average assembly burnup applied to the batch's maximum integrated planar-radial power peak. A single net penalty for COLSS and CPC is then determined from the penalties associated with each batch, accounting for the offsetting margins due to the lower radial power peaks in the higher burnup batches. 3/4.2.5 RCS FLOW RATE This specification is provided to ensure that the actual RCS total flow rate is maintained at or above the f.;inimum value used in the LOCA safety analyses. 3/4.2.6 REACTOR COOLANT COLD LEG TEMPERATURE This specification is provided to ensure that the actual value of reactor coolant cold leg temperature is maintained within the range of values used in the safety analyses. 2.4.2.7 AXIAL SHAPE INDEX The Axial Shape Index (ASI) is a measure of the power generated in the lower half of the core less the power generated in the upper half of the core divided by the sum of these powers. This specification is provided to ensure ~ that the core average ASI is maintained within the range of values assumed as an initial condition in the safety analyses. This range is specified as 

                -0.3 1 ASI 1 0.3.

The ASI can be determined by utilizing either the Core Operating Limit Supervisory System (COLSS) or any operable Core Protection Calculator (CPC) channel. The real time monitoring capability and accuracy of COLS$ allows COLSS to monitor power. limit margins closely. Consequently, the ASI-limit is broader than it would be with the same core without COLSS. The COLSS con-tinuously calculates the ASI and compares the calculated value to the param-eter established for the COLSS ASI alarm limit. In addition, there is an uncertainty associated with the COLSS calculated ASI, therefore the COLSS ASI alarm limit includes this uncertainty. If the LC0 is exceeded, COLSS alarms are initiated. The ASI safety setting is selected so that no safety limit will be exceeded as a result of an anticipated operational occurrence, and so that the consequence of a design basis accident will be acceptable. SAN ONOFRE - UNIT 3 8 3/4 2-4 AMENDMENT NO. 51

POWER DISTRIBUTION LIMITS 

               , BASES AxlAL SHAPE INDEX (Continued)

With COLSS out of service, any operable CPC channel may be used to cal-culate the ASI (using three axially spaced excore detectors). The axial shape synthesis in the CPC's shows the relative power produced as a function of core height in each third of the core. Due to the uncertainty associated with the CPC estimate, the ASI is restricted to a smaller range than the range calcu-lated using the COLSS. The 20% rated thermal power threshold is imposed due to the inaccuracy of 

                                                                                                                  ~

the neutron flux detector below the threshold. Core noise level is too large to obtain usable detector readings. 3/4.2.8 PRESSURIZER PRESSURE This specification is provided to ensure that the actual value of , pressurizer pressure is maintained within the range of values used in the - safety analyses.

  • SAN ONOFRE - UNIT 3 8 3/4 2-5 AMENOMENT NO. 51

ATTACHMENT C PROPOSED TECilNICAL SPECIFICATIONS AND BASES UNil 2 l' 1

3/4.2 POWER DISTRIBU110N LIMITS 3/4.2.1 LINEAR HEAT RATE 11MITING CONDITION FOR OPERATION 

         -3.2.1       The linear heat rate shall not exceed 13.9 kw/ft.

APPLICABillTY: MODE 1 above 20% of RATED THERMAL POWER. ACTION: With-the44near-heat-rate-exceeding-41s44mit+r-as-4ndicated4y-e4ther-(1)- the COL 4S-salcu la t ed-co re-powee-exceedi ng-t he-COL 4&-calculo t ed-c ore-power ope ra t4 ng 44 ml44a sed-+n-k wH4+-or-(2bwhen-t he-COL 4S-4+-not4eing-used ,-any OP ER A Bl:E-local-Powee-Den s44y-c ha nnel-e *ceedi ng-t he44 nea r-hea t-ra te44 mi+r wi thin-4 G-m i nu tes-4 n444 a te-co rr+c44ve-a el4 on-to-reduc +-t he44 nea r-hea t-ra te-t o - within-t he44mits-and-e44her4 a r--Res t ore-t he44 nea e-hea t-ra t e-t o-w i t hi n4t s-14 mi4+-within-one-houer - OF

b. h - i n-a t4 east 440T4T ANDBY-within-the-nex t-6-hours,
a. 'With COLSS in service and the linear heattrate'not'being-maintainedTas
                  ' indicated by.COLSS calculated 7. ore power exceeding the"COLSS calculated
                                                       ~

core. power operating limit based on -linear heat rate;(kw/f t):' l '. Restorethe^11nearheatrate'towithiniitsflimitslwithin111hourf or 2;- ' Reduce THERMAL" POWER to'less'than' ori e'qualTto '20% ofjRA1ED 

                                    ' THERMAL POWER within the next 6 hoursi_
b. ;With COLSS nothintservice and:the linear-heatTrate not being/ maintained:as'
                 ' indicated by any OPERABLE Local Power Density;channeliexceeding ~thellineap
                                                                  ' ~      ' ~                               ~~

heat: rate limit: 

                    '11             :Within 15 minutesTinitiate surveillance? requirement 74.2;113fand                    -
                                    'restorethelinearheat'ratetowithi_n.limitswithinj4; hours;iof 2;-             2 Reduce THERMAL' POWER to"less?thanlor~ equal? to{20C of/ RATED       '

THERMAL:. POWER within thelnext-6 hours; ~ SURVFill ANCE RE001REMENTS 4.2.1.1 The provisions of Specification 4.0.4 are not applicable. 

         -4.2.1.2          The linear heat rate shall be determined to be within its limits when THERMAL POWER is above 20% of RATED THERMAL POWER by continuously monitoring the core power distribution with the Core Operating Limit Supervisory System                                        .

(COLSS) or, with the COLSS out of service, by verifying at least-once per 2 hours that the linear heat rate, as indicated on all OPERABLE Local Power Density channels, is within the limit of 13.9 kw/ft. 4.2t1 39 WIth'COLSSinotM n1 service and#theTlinear~heatTrate'not7being maintained 

          'as indicated 1by'any 0PERABLE: Local Power 0'ensity Channel t.xcer. ding {the linear ~ ^
                         ~

heat ratetlimitiverify"every;15 minutes that therefi'sLnofedverseittendliphe linear: heat rate.

i 4.2.1.34 At least once per 31 days,- the COLSS Hargin Alann ,nall be verified to , actuate ~at a TilERMAL POWER level less than'or equal to the core power operating limit based on kw/ft. -! 

                                                                                                                                   .i i

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h i SAN ONOFRE-UNIT 2' 3/4 2 AMENDHENT'NO. 

                                       <    -           ,                        ,.  .w. ., . ,   .      . = . - . , , . . - . . -

POMER DISTRIBUTION LIMITS 3/4.2.4 DNBR MARGIN LlHITING CONDITION FOR OPERATION ,, 3.2.4 The DNBR margin shall be maintained by one of following methods:

a. Maintaining COLSS calculated cote power less than or equal to COLSS calculated core >ower operating limit based on DNBR (when COLSS is in service, and eitler one or both CEACs are operable); or
b. Maintaining COLSS calculated core power less than or equal to COLSS calculated core power operating limit based on DNBR decreased by 13.0% RATED THERMAL POWER (when COLSS is in service and neither CEAC isoperable): or
c. Operating within the region of acceptable operation of Figure 3.2-1 using any operable CPC channel (when COLSS is out of service and either one or both CEACs are operable); or
d. Operating within the region of acceptable operation of Figure 3.2-2 using any operable CPC channel (when COLSS is out of servi:e and neither CEACs is opera' ole).

APPLICABill1Y: MODE 1 above 20% of RATED THERMAL POWER. ACTION: W Ft h-t he-DN BR-ea rgin-no t-being-ma in ta inedr-a s-indi ca ted-by+ tl)-COL-S S-c a lc+14 ted-<-o re-power-ex ceed i ng-the-a ppropet a te-G01:SS oalculated-operat4n944mi+r-or 43)-W it h-001-SS-ou t-o f-ser44 ee r-ope Fa t4e n-ou ttide-t he-region-o f-aGEeptdle-opera (4en-of-f49 ure-M-1-or - 3.2 -2 r W 4 t h i n--16-minu t es-4n tt4 a te-correc44ve-est4en-t o-resto re-the-ON BR-to-wit hin4ts 44m14+r-and-e4 then

4. Res to re-the-DN BR-t o-wit hi n-44-s44 mit-s-M 4 h 4 n-one-ho'4 r1--o r
b. Be-i n-a t-least-HOT-STANDBY-w i t hin-the-nex t-6-hou r+r ai 7With~COLSSfin service"and the DNBR limitinotJbeing maintained:asEindicated
                                       '"byiCOLSSLcalculated core power exceedingt^^ theTCOLSS calculated
                                                                                                      '~    "      ~ '" core 1p"ower' operating:li.mit based on:DNBR:~

l'.1Restorej the; DNBRf toTwithi.nfits limit.s1withiL1l hour;for

2.'Feduce THERMAL 2POWERitoilessithanlor equalbto 20C ofLRATE01THERMAlj " ~
                                              ~ POWER within-theinext-6 hours.

b.' , L With?COLSS'notlinLservice and the: DNBRilimitt not:betag" maintained as 

                                ~
                                         ~indilcated by!operationDoutside; the1 region ofiacceptableLoperati.0,n'of
                                                                                                                 ~

Figure:3.2al;or>3.242 usingfany. operable CPClchannelp 1;;Within71S'minuteslinitiateL surveillance}equirement?4;2T4:37and ' ~ ~ restore 

                                                                                                                                ^ ' ~ '
                                              ~the DNBR to withintI.ts limitsfwithin:41hoursfor" 2.lReduce THERMAL? POWER;tonless!than?orfeqdalito; '

20_%r of7ATEDfTHERMAll POWER;withinfthernext 6 hours'. i SAN ONOFRE-UNIT-2 3/4 2-5 AMENDMENT NO.

SURVElltANCE RE001REHfNTS .. 4.2.4.1 The provisions of Specification 4.0.4 are not applicable. 4.2.4.2 The DNDR shall.be determined to be within its limits when THERMAL POWER is above 20% of RATED THERMAL POWER by continuously monitoring the core power distributionwiththeCoreOperatingLimitSupervisorySystem(COLSS)or,with the COLSS out of service, by verifying at least once per 2 hours that the DNBR, as indicated on any OPERABLE DNBR channel, is within the limit shown on Figures 3.2-1 or 3.2-2, as appilcable. , 4;2.4'.3'.lWith COLSS?not in service and the'DNBRimargin'not' being" maintained"as?^ indicated by operation outside the' region of. acceptable._ operation of figure" 3.2 1 or.3'.2-2 using any operable CPC channel, verify.ever jl5l minutes that-there is._no adverse; trend _.in 0NBR margin; 4.2.4.34 At least once per 31 days, the COLSS Margin Alarm shall be verified to actuate at a THERMAL POWER level less than or equal to the core power operating limit based on DNBR. i l l SAN ON0FRE-UNIT 2 3/4 2-6 AMENDMENT NO.- L-

3/4.2 POWER DISTRIBUTION LIMITS BASIS 3/4.2.1 LINEAR tlEAT RATE The limitation on linear heat rate ensures that in the event of a LOCA, the peak temperature of the fuel cladding will not exceed 2200*f. Either of the two core power distribution monitoring systems, the Core Operating Limit Supervisory system (COLSS) and the Local Power Density channels in the Core Protection Calculators (CPCs), provide adequate monitoring of the core power distribution and are capable of verifying that the linear heat rate does not exceed its 4t+ limits. The COLSS performs this function by continuously monitoring the core power distribution and calculating a core power operating limit corresponding to the allowable peak linear heat rate. Reactor operation at or below this calculated power level assures that the limits of 13.9 kw/ft are not exceeded. The COLSS calculated core power and the COLSS calculated core power operating limits based on linear heat rate are continuously monitored and displayed to the operator. A COLSS alarm is annunciated in the event that the core power exceeds the core power operating limit. This provides adequate margin to the linear heat rate operating limit for normal steady state opera-tion. Normal reactor power transients or equipment failures which do not require a reactor trip may result in this core power operating limit being exceeded. in the event this occurs, COLSS alarms will be amunciated. if the event which causes the COLSS limit to be exceeded results in conditions which approach the core safety limits, a reactor trip will be initiated by the Reactor Protective Instrumentation. The COLSS calculation of the linear heat rate includes appropriate penalty factors which provide, with a 95/95 probability / confidence leve!, that the maximum linear heat rate calculated by COLSS is conservative with respect to the actual maximum linear heat rate existing in the core. These penalty factars are determined from the uncertainties associated with planar radial peaking measurement, engineering design factors, axial densification, software algorithm modelling, computer processing, rod bow and core power measurement. The core. power distribution and a corresponding power operating L11mit based on Linear lleat Rato'(LHR) are more accurately 1 determined byLthe>COLSS using;the incore detector system.1 ~ The: CPCs determine LilRsless accurately:with thetexcore detectors.E When COLSS is nottavailable'the TS LCOs-are:more' ^

  • restrictive due to the uncertainty off the CPCs. Jiow~ever, when1COLSS:becoines inoperable the added margin associated with CPC; uncertainty 11sonot11mmediately required and-a 4 hour ACIl0N is provided for appropriate corrective:actinn.

Paratreters required to maintain the operating limit power level based on linear heat rate, margin to DNB and total core power are also monif.ored by-the CPCs assuming minimum core power of 20% RATED 1HERMAL POWER- The 20% Rated Thermal Power threshold is due to the neutron flux detector system being inaccurate below 20% core power. Core noise level at low power is too large to obtain usable detector readings. Therefore, in the event that the COLSS is not being used, operation within-the limits of Figure 3.2-2 can be maintained by utilizing a predetermined local power density margin and a total core power limit in the CPC trip channels. The above listed uncertaint) penalty factors plus those associated with startup test acceptance criteria are also included in the CPCs. SAN ON0ERE-UNIT 2 B 3/4 2-1 AMENDMENT NO.

3/4.2+ POWER-DISTRIBUTION L1H1T5 

                                                                                                   ~

BAsrs- -' _ 3/4;2;1 "L % / HEAT RATEG-(Continued) 1 Wilile operating with the; COL 55 cut of service,'the CPC calculated!LHRiis a - monitored every 15 minutes to -identify any adverse trendi f.nlthermalimargini: The ~ of LHR duri_ngithe14 hour:--actio'n -period ensures that' jncreased monitoring:in11s apegete: safety _ marg maintained for anticipated operationalfoccurrences'and no;rd '- d accident results in consequences more'severeithanithose described ~ 

                                                                                          ~
                                                                                              "'     '  ~                   '

l *:.g A the-UFSAR.; i nan 

   --      --a_-._---_______              _           _ _ _ _ _ _          _ _ _ _ _ ____        _

POWER DISTRIBUTION LIMITS BASES , DNBRMarcin(Continued) T he rc o re jowe r; d i s t ri bb ti on~a nd 7a t c 6 rre s po n d i ng ~iowe rWp e rht i nfl imi t based on DNBRiare morelaccuratelyEdetermined by1the:CO.SS utingGtheNncore" detector; sys' tem.: ?The: CPCs idetermine<DNBRiless accurately with the. excore" detectorskiln<additionktheCOLSSreserves:'aDNBRioverpowermarginitofensures r that the? specifiedl acceptable s fuelf designilimitsv are"notieiceededlirnthe event offan'! anticipated; operational! occurrenceM1herefore, thetCOLSS?06t3f Tservice TS LCOs areimoreL restrictive ldue;to the uncertaintyfofithe: CPCsf andjLthe" ~"' overpower!marginireserved for?anticipatedLoperationalioccorrences;)!However? When-COLS$ becomesainoperable>tholadded' margin 1 associated!withithe?CPCsCisinot immediatelyfrequiredandia34 h'our ACTIONEis provided foriappropriateicofrectjje betion.' . The DNBR penalty factors listed in section 4.2.4.4 are penalties used to accommodate the effects of rod bow. The amount of rod bow in each assembly is dependent upon the average burnup experienced by that assembly. Fuel assemblies that incur higher average burnup will experience a greater magnitude of rod how. inversely, lower burnup assemblies will experience less rad bow. The penalty r each batch required to compensate for rod bow is determined from a batch's 

     ,aximum average assembly burnup applied to the batch's maximum integrated alanar-radial power peak. A single net penalty for COLSS and CPC is- then determined from the penalties associated with each batch, accounting for the offsetting margins due to the lower radial power peaks in the higher burnup batches.

COLSS outiof service Wthe"CP_C?cEl:ulatddiDNBR?fs WhileLoperating;;With2the: moni16 red (every 15.'mindtes?tolidentifylany1advsrsettrend%ihithermslfmargin!M~The ^ 

   .increnedimonitoringLoffDNBRrduring:thej4"hourdaction? period [ ensures that"'

adequate? safety margin 1Mmaintained for'anticipatedfoperationalfoccurrence"sTarid 

   .no; postulated4 accidentfresul;ts in consequences 7more severeQhanytt                      ! osydesc,ribef

_iniChapterf15)off the;UFSAR. 3/4.2.5 RCS FLOW RATE This specification is provided to ensure that the actual RCS total flow rate is maintained at or above the minimum value used in the LOCA safety analyses. 3/4.2.6 REACTOR COOLANT COLD LEG TEMPERATURE l This specification is provided to ensure that the actual value of reacter coolant cold leg temperature is maintained within the range of values used in the safety analyses. 2.4,2.7 AXIAL SHAPE INDEX The Axial Shape Index (ASI) is a measure of the power generated in the

lower half of the core less the power generated in the upper half of the core divided by the sum of these powers. This specification is provided to ensure that the-core average ASI is maintained within the range of values assumed as an initial condition in_the safety analyses. This range is sp'ecified as
   -0.3 s ASI 5 0.3.

SAN ON0FRE - UNIT 2 B 3/4 2-4 AMENDMENT N0.

POWER DISTRIBUTION LIMITS BASES 2.4.2.7 AX1AL SHAPE INDEX (Continued) The ASI can be determined by utilizing either the Core Operating Limit Supervisory System (COLSS) or any operable Core Protection Calculator (CPC) channel. The real time monitoring capability and accuracy of COLSS allows COLSS to monitor power limit margins closely. Consequently, the ASI limit is broader than it would be with the same core without COLSS. The COLSS continuously calculates the ASI and compares the calculated value to the parameter established for the COLSS ASI alarm limit. In addition, there is an uncertainty associated with the COLSS calculated ASl; therefore the C0'_SS ASI alarm limit includes this uncertainty. If the LC0 is exceeded, COLSS alarms are initiated. The ASI safety setting is selected so that no safety limit will be exceeded as a result of an anticipated operational occurrence, and so that the consequence of a design basis accident will te acceptable. With COLSS out of service, any operable CPC channel may be used to cal-culate the ASI (using three axially spaced excore detectors). The axial shape synthesis in the CPC's shows the relative power produced at a function of core height in each third of the core. Due to the uncertainty associated with the CPC estimate, the ASI is restricted to a smaller range than the range calculated using the COLSS. The iO2 rated thermal power threshold is imposed due to the inaccuracy of the neut" a flux detector below the threshold. Core noise level is too large to obtain usable detector readings. 3/4.248 PRESSURIZER PRESSURE This specification is provided to ensure that the ac*uai value of ' pressurizer pressure is maintained within the range of valuai used in the safety analyses. SAN ONOFRE - UNIT 2 B 3/4 2-5 AMENDMENT NO. l

S ATTACllMENT 0 PROPOSED TECHNICAL SPECIFICATIONS AND BASES UNIT 3-M 

                                         ?

b &

3/4.2 POWER DISTRIBUTION LIMITS 3/4.2.1- LINEAR HEAT RATE LIMITING CONDITION FOR OPERATION l 

    .3.2.1 The linear heat rate shall not exceed 13.9 kw/ft.

APPLICABILITY: MODE 1 above 20% of RATED THERMAL POWER. ACTION: W4h-the-14near-heat-rate-exeeeding,41e.r-14 mms, as indleated-by-ekher-{43--the COL 4S-salculated-core-power-exceeding-the-COL-SS-edeukted-core power Operating 14 m i t-ba sed-on-4 w/4t-t-o r-($ + hen-the-GOL-SS-4+-not-be4 ng-usedr-any-OPERABh6 Local Power-Gens 4ty-channel-exceeding-the-44near-heat-rate-14e4r-wMbie-45 mi nutes--in44a te-c o r rec t i ve-ae14on-to-reduce-the-44near-hea t--ra te-tc - w I t h i n 14te 44mus-and-el-ther+ Restore-the linear-heat-rate-to-*Mbin-4te -44mR+-*4hin One heuer

a. e or
b. Se in-at-least-HOT-STANDBY-wkh4n-the-next-G-hour +r
u. 7Wi thTCOLS$ (inherViceland ithe211near? heatt rateTnot? baing'niaintained Ts indicated by,COLSSicalculated corecposer:exceedi.nghthe:TCOLSSicalculated ~ ~"

core power operating 311mit basedjon linear l heat (ratel(kW/ft)[ ^ 1 M_J~ Re sm t o re-st hcl _i n ea_r ? h_es t? ra t.e -<t- oi 

                                                           .     .       _           - -wi t h_i n ei _t s ?l i mi tsWi t_hi
                                                                                                                           -- n T it ho_lfr if i Re d u c eXTi1ERMAl'POWERit ol l e s si t hanTo r'eq u a li to? 20Wo      f? RATE 07 TH ERMAL 2 '. ~ '                                                                          " * ' " " " " ~ " ~~
                          ]OWER jithinkt,hefnext!6thours ~  ' ~ ' ' '

bb EWith'COLSS:notfin?serViceTand therlinear7hebt7 rate (notybeing!maintainedlai F 

            ~ indicated byXanyc0PERABLEllocal
  • P6Wer; Den lsity"%channekexcee." ding theilissiF
                                                                                             '                          ~"

heatiratej. limit? 

                                                       ~

11 TWithinT15" minutes 1 initiate surveillance"requiredsnt?4?2f113fand 

                           -restore    - , . 7theilin,
                                             ~ -        ear heatirateltbiwithin, ~tlimitswith.

_ . mm inl4_thourshor m __m

21. Reduce? THERMAL 1 POWER to'less EthahTor'eq"dalitd7200 ' ~ 'oflRATEDiTHERMAL
                                                                                                        " '"'            ^
                         " POWER withinTtheinext:!6thours; ' " ' ~

SURVEILLANCE REQUIREMENTS $ 4.2.1.1 The provisions of Specification 4.0.4 are not applicable. 4.2.1.2 The linear heat rate shall be determined to be within its limits when THERMAL POWER is above 20% of RATED THERMAL POWER by continuously l- monitoring the core power distribution with the Core Operating Limit Supervisory L System (COLSS) or, with the COLSS_out of service, by verifying at least-once per I 2 hours- that the linear heat rate, as indicated on all OPERABLE Local Power. , Density channels, is within the limit of 13.9 kw/ft. p ! 4;2:1!3! JWith C0l.SS?not7in' service 7andithe?lineaMheatWatein6t;being i - maintainediaslindicated byEany? OPERABLE 1LncaliPoWeKDensit[yRhantielsexceeding l theilineaHheattratesliinitRverify^Tever ~ ~ 915 

                                                                     " '   minutesithatithereTis:WoFadysrse~
                                                                                  ~ ~ ~' " '""" ~""

trehdin/the11inearTheat?ratel UMw u #' ' 

                          .3.: ' A ' '    -*h'3 # k
                                                           ~

!E

At least .once per 31 days; the COLSS Margin ~ Alarm shall, be verit ed 4.2.1.34 to actuite at a THERMAL POWER level less than:or equal to the core power-operating limit based-on kw/f t. i , , l l i-I l 

  .                                                                                                             M SAN ONOFRE-UNIT 31                      3/4 2-1                     AMENDMENT NO.
       *_                                                                j

POWER DISTRIBUTION' LIMITS 3/4.2.4 DNBR MARGIN 1IMITING CONDITION FOR OPERATION 3.2.4 The DNBR margin shall be maintained by one of following methods:

a. Maintaining COLSS calculated core power less than or equal to COLSS calculated core power operating limit based on DNBR-(when COLSS is-in service, and either one or both CEACs are operable); or-
b. Maintaining COLSS calculated core power less than or equal to COLSS calculated core power operating limit based on DNBR decreased by 13.0% RATED THERMAL POWER (when COLSS is in -service and neither CEAC is operable): or c.- Operating within the region of acceptable operation of Figure 3.2-1 using any operable CPC channel (when COLSS is out of service and either one or both CEACs are operable); or'
d. Operating within the region of acceptable operation of Figure 3.2-2 using any operable CPC channel (when COLSS is out of service and neither CEACs is operable).

APPLICABILITY: MODE 1 above 20% of RATED THERMAL POWER. ACTION: WMh-the-DNBR-marg 4n-not-beiag maintaincd, as ind4cated4y+ 

               -(1)     COL-SS-ealeuhted-sore-p0wer exceeding = the-appropr4atc COLSS sakuhted-oper+t4eg4imMer
               -(2)    With-G0LSS Out of service. Operat40n outs 4de-the-reglen of asseptable-oper+t4en-of-44              9 urc 3.2 1 Or-3r2-2r Wi-th4n-45-minutes-inM4 ate-correctivc aet4on-to-rester +-ttc DNSR t0 Within 4 t+-MaM s , and - e Mher+
a. Restore-the-DNBR t0 .,itMn it; 1imMs-w&tMn-ene-hearr-OF
h. Je in-at-leasrt HOT STANDBY-*MMn-the-ne*t-6-hour +r
i. at 5WithrCOLSSiirissediceiand1thEDNBR71imitr nbtTbsi~ngimdi6thinedlWQin'didtsd l byfCOLSScalhulatsdLcoreipowerJex6eeding"thei.COLSSical501atedfcoreip"osef
                                                                         ~             "'"                ~ ~'           "'   ~

operating;11mitFbasedlon(DNBR:f l lb JRes toreithe7 DNBR?toTWi - - - ~ thi ni. .f ts fl imi ts ?wi thi 

                                                                                       -   n11(hourN. _or

! 2h _"5 Reduce?THERMALY POWERitots'ssthanTor* e' 'ualNtoT20W6f! " ' " ^ " ~'"# RATED 3THERflAC l ,POWERfwithin(the. 

                                ~   _.-

n_extT6IhoursI _m 

                                                                                    ' ' ~ ^^q b?

iWith7COLSSinbt(infserVicefandith'elDNBR511mitsnotibeilngimiinthindd?is - l ~ indicated byLoperationLostsidefthelregion?ofia:heptabl% op"eration:of ~"* ! Figure 

               -        23f
                          + ~tlifor
                               - . 3W2f.d_ sing ~lanyioperable!CPC?ch_anneld.

a---~ u f. E T 7Withir615' min 6tesEiiittiatsisurveT1hndeliequiF#msntT412?4?3?in'd 

               "                                                                                                            ^
                    " Yes
                       -~   to r.Fthe ~_~ DNBR i to ? wi th     ~ i. nl i  v tsil imi .ts
                                                                                       .- ii thi rF4 ? hoirsWor~

L 2? TReducchiHERMAL; POWER "to51 es s? thsnV equal 7 "to? 20Fo f? RATEDITHERMAL' 

                                                                                                                ~ ~ ~ ~~

i, ". POWER m Wi. thin m. i 7the nextr6thour.s; m i SAN ON0FRE-UNIT 3 3/4 2-5 - AMENDMENT- N' O. - L \

SURVElllANCE REQUIREMENTS- _ 4.2.4.1 The provisions of Specification 4.0.4 are not applicable. 4.2.4.2 lThe DNBR shall be determined to be within its limits when-THERMAL POWER is above 20% of RATED THERMAL POWER by continuously monitoring the core power distribution with the Core Operating Limit Supervisory System (COLSS) or, with the COLSS out of service, by verifying at least once per 2 hours that the DNBR, as indicated _on any OPERABLE ONBR channel, is within the limit shown on Figures 3.2-1 or 3.2'-2, as applicable. 4;2;4'.35With COLSS not?inTservic?'and the _DNBR"margi_ninotEbeing':^niaintainedsssil indicated by operation 1outside:the/ region of acceptablejoperationfoWFigure* ~' 3:2-1C ort 3.2-2.. using janyToperablef CPC; channel .4 veri fy)~every'L 

                                                                    "~

IS? miilutes' that 

                                                                           ' " ~ " ' '
                                                                             '               ~
 }herel-is'~ noja_dvers'eftrend in DNBR. margin;.

4.2.4.33 At least once per 31 days, the COLSS Margin Alann shall be verified to actuate at a THERMAL POWER level less than or equal to the core ' power operating limit based on DNBR. , SAN ONOFRE-UNIT 3 3/4 2-6 AMENDMENT N0.

3/4.2 POWER DISTRIBUTION LIMITS BASES __ 3/4,2 11 LINEAR HEAT RATE The limitation on linear heat rate ensures that in the event of a LOCA, the peak temperature of the fuel cladding will not exceed 2200'F. Either of the two core power distribution monitoring systems, the Core Operating Limit Supervisory System (COLSS) and the Local Power Density channels in the Core Protection Calculators (CPCs), provide adequate monitoring of the core power distribution and are capable of verifying that the linear heat' rate does not exceed its 4h limits. The COLSS performs this function by continuously monitoring the core power distribution and calculating a core power operating limit corresponding to the allowable peak linear heat rate. Reactor operation at or below this calculated power level assures that the limits of 13.9 kw/ft are not exceeded. The COLSS calculated core power and the COLSS calculated core power operating limits based on linear heat rate are continuously monitored and displayed to the operator. A COLSS alarm is annunciated in the event that the core power exceeds the core power operating limit. This provides adequate margin to the linear heat rate operating limit for normal steady state opera-tion. Normal reactor power transients or equipment failures which do not require a reactor trip may result in this core power operating limit being exceeded. In the event this occurs, COLSS alarms will be annunciated. If the event which causes the COLSS limit to be exceeded results in conditions which approach the core safety limits, a reactor trip will be initiated by the Reactor Protective Instrumentation. The COLSS calculation of the linear heat rate includes appropriate penalty factors which provide, with a 95/95 probability / confidence level, that the maximum linear heat rate calculated by COLSS is conservative with respect to the actual maximum linear heat rate existing in the core. These penalty factors are determined from the uncertainties associated with planar radial peaking measurement, engineering design factors, axial densification, software algorithm modelling, computer processing, rod bow and core power measurement. ! The core powerTdistributionfandHalorresponding'; power?oseratingslimit b'asedYontLinearJHeat Rate (LHR)"arelmoreia'ccurately? determined?ay%thelCOLSS-usingithelincore detectorisystema 4h'eiCPCsideterminefLHRiles's facc~uratelysith thesexcore'detectorse rWhen COLSSLis not5availableithelT5KLCOs7areimoret ~ ~^" restrictiveduetto;theuncertaintfofLthelCPCsMHowevefWwhenlCOLSSjbechef inoperable 1theLa'dded margintassociated with C PC ! U n c e rt a i_ n tyli s yno t%i mmed i a tel y required:andfa(4 hourLACTIONii sj provided; fonappppripte/ corrective { action;; Parameters required to maintain the operating limit power level based on linear heat rate, margin to DNB and total core power are also monitored by the CPCs assuming minimum core power of 20% RATED THERMAL POWER. The 20% Rated L Thermal Power threshold is due to the neutron flux detector system being 

        -inaccurate below 20% core power. Core noise level-at low power is too large to obtain usable detector readings. Therefore, in the event that the COLSS is not-being used, operation within the limits of figure 3.2-2 can-be maintained by-utilizing a predetermined local power density margin and a total core power limit in the CPC trip channels. The above listed uncertainty penalty factors l        plus those associated with startup test acceptance criteria are also included in                      '

I the CPCs. SAN ON0FRE-UNIT 3 B 3/4 2-1 AMENOMENI' NO. L 

    }/A T ~ POWER DISTRIQUTION LIMITS BAQ3?

3/4,2,1 LINEARHEAT" RATE;;(Continued) While" operating With1the' COLSS'outloff servicVthe~; CPCl calculated LHRiis moni_tored every 15 minutes- to identify any adverse trend in thermallmargin;:g)The the 4 hour action period ~ ensures'.that ~ ladequate increased monitoring safety. margin;is of-'LHR during 'd for anticipated operational' occurrences tand-niaintaine no _postul_ated accident resultsili) consequences mote: severe thanLthose:' described' in' Chapter 115; of the UFSAR. k 

                                                '       '        B;3/4 2-la"                       MiENDMENT NOE~

SAN 0NOFRE-UNIE3': ,

POWER DISTRIBUTION LIMITS BASES DNBR Marain (Continued) TheTc6re powerTdistributi6n andiaLcorresp6.nding4oserTnpsrdling311mit basedfon' DNBRiaretmore accurately' determined byithe;COLSS usingTtheiincore' " detecto'r system.JihelCPCsidetermine DNBRLless accurately;with the'excore" i detectors.1 In' addition,4thelCOLSSLreserves valDNBRToverpower margin toiensure  ! that? therspect fied iacceptablef fuelfdesignElimi ts/areinotsexceedeOin Lthe r even1 ' bflan1anticipatedToperationalf occurrence.: LThereforef the1COLSS;loutloff service; TSiLCOs rare' morer restrictive;due sto the: uncertainty : oft the"CPCsia'n'dthe" ~ ~~~~ i o whenTCOLSSibecomesYinoperablethe?addedmarginassoci)ated"withithe' CPCsbis n6t- ver immediateltreguirsd andla 4 hourLACTION;(is froyided;forJspprpriatefeofrectjvj action; A DNBR penalty factor has been included in the COLSS and CPC DNBR calculation to accommodate the effects of rod bow. The amount of rod bow in each assembly is dependent upon the average burnup experienced by that assembly. Fuel assemblies that incur higher average burnup will experience a greater magnitude of rod bow. Conversely, lower burnup assemblies will experience less rod bow. In design calculations, the penalty for each batch required to compensate for rod bow is determined from a '.atch's maximum average assembly burnup applied to the batch's maximum integrated planar-radial power peak. A single net penalty for COLSS and CPC is then determined from the penalties associated with each batch, accounting for the offsetting margins =due to the lower radial power peaks in the higher burnup batches. Whilej operatinglwith2thef COLSSEcutf ofisdrvisb?the%PCicaleslatedMRiis monitored (every115 minutes!tolidentifyjanyladversel trend (initherma1*inarginQhle increased monitorjng of DNBR duringJtheL4 ho action period 3nsures(that' adequate safety margin 1simaintainedifor! ant @icipatedl operational 70ccurrencesT bo) postulated rl accident?[{esultsfin y consequences morey 

         ;inChapter15;ofthe)UFSAR;.

e 3/4.2.5 RCS FLOW RATE This specification is provided to ensure that the actual RCS total flow rate is maintained at or above the minimum value used in the LOCA safety. analyses. 3/4.2.6 REACTOR COOLANT COLD LEG TEMPERATURE l ...is specification is provided to ensure _that the actual value of l reactor coolant cold leg temperature is maintained within'the range of values used in the safety analyses. l 2.4.2.7 AXIAL SHAPE-INDEX l l- The Axial Shape Index (ASI) is a measure of the power generated in the-lower half of the core less the power generated in the upper half of the core divided by the sum of these powers. This-s)ecification is provided to ensure that the core average ASI is maintained wit 1in the range of values assumed as an l-initial condition in the safety analyses. This range is specified as 

         -0.3 < ASI < 0.3.

SAN ON0FRE-UNIT 3 8 3/4 2-4 AMENDMENT NO.

  • I P0':!ER DISTRIBUTION LIMITS BASES 2.4.2.7 AXIAL SHAPE INDEX (Continued)

The ASI can be determined by utilizing either the Core Operating Limit Supervisory Systen-(COLSS) or any operable Core Protection (alculator (CPC) channel. The real time monitoring capability and accuracy of. COLSS allows COLSS to monitor power limit margins closely. Consequently .the ASI limit-is broader than it would be with the same core without COLSS. The C0oSS continuously calculates the ASI and compares the calculated value to the parameter established for the COLSS ASI alarm limit. In addition, there is an uncertainty associated with the COLSS calculated ASI, therefore the COLSS ASI alarm limit includes this uncertainty. If the LC0 is exceeded, COLSS alarms are initiated.- The ASI safety setting is selected so that no safety limit will be exceeded as a result of an-anticipated operational occurrence, and so that the consequence of a design basis accident will be acceptable. With COLSS out of service, any operable CPC channel may be used to cal-culate the ASI (using three axially spaced excore detectors). The axial shape-synthesis in the CPC's shows the relative power produced as a function cf core height in each third of the core. Due to the uncertainty associated with the CPC estimate, the ASI is restricted to a smaller range than :he range calculated using the COLSS. The 20% rated thermal power threshold is imposed duc to the inaccuracy of the neutron flux detector below the thieshold. Core noise 1(vel-is too large to obtain usable detector readings. ' 3/4.2.8 PRESSURIZER PRESSURE This specification is provided to ensure that the actual value of pressurizer pressure is maintained within the range of values used in the safety analyses. SAN ON0FRE - UNIT 3_ 8 3/4 2-5 AMENDMENT N0.  : 

                                                                                                              =
                                                      -                              _ . _ _ _ _ _ _ _ . _ }}
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