ML20101F736

Application for Withholding Study Re ESF Actuation Sys Setpoint Methodology (Ref 10CFR2.790)

ML20101F736
Person / Time
Site:	Beaver Valley
Issue date:	11/06/1984
From:	Wiesemann R WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
To:	Knighton G Office of Nuclear Reactor Regulation
Shared Package
ML19274C553	List: ML20101F718 ML20101F736
References
CAW-84-97, NUDOCS 8412270286
Download: ML20101F736 (19)

Text

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[ Enclo:ure 5

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sJ Nuclear Technology D;nsion Westinghouse Water Reactor Electric Corporation Divisions Box 335 PittsburghPennsylvanta 15230 November 6,1984 Mr. George W. Knighton, Chief CAW-84-97

. Licensing Branch No. 3 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C. 20555 APPLICATION FOR WITHHOLDING PROPRIETARY INFORMATION FROM PUBLIC DISCLOSURE SUB.1ECT: Westinghouse Input to Beaver Valley Power Station Unit 2 Setpoint Study REF: Duquesne Light Company Letter, Woolever to Knighton, dated November 1984

Dear Mr. Knighton:

The proprietary material for which withholding is being requested is of the same technical type as that proprietary material previously submitted by Westinghouse concerning reactor Protection System / Engineered Safety Features Actuation System Setpoint Methodology. The previous application for withholding, AW-76-60, was accompanied by an affidavit signed by the owner of the proprietary information, Westinghouse Electric Corporation.

Further, the affidavit submitted to justify the previous material was approved by the Commission on April 17, 1978, and is equally applicable to the subject taterial.

Accordingly, it is respectfully requested that the subject information which is proprietary to Westinghouse and which is further identified in the affidavit be withheld from public disclosure in accordance with 10CFR Section 2.790 of the Consnission's regulations.

Correspondence with respect to the proprietary aspects of the application for withholding or the Westinghouse affidavit should reference CAW-84-97 and should be addressed to the undersigned.

B Very truly yours,

{jj22702k6$og&p ADOC o ~

PDR p y )

/Isb 86be A. Wiesemann, Manager -

p

• Reg atory & Legislative Affairs Attachment cc: E. C. Shomaker, Esq.

Office of the Executive Legal Director, NRC

i

• Enclosure No. 2 i TABLE 2.2-1 REACTOR TRIP SYSTEM INSTRUMENTATION TRIP SETPOIITTS FUNCTIONAL UNIT TRIP SETPOINT ALIDWABLE VAIRES

1. Manual Reactor Trip Not Applicable Not' Applicable

2. Power Range, Neutron Flux Iow Setpoint - < 25% of RAT ED Iow Setpoint - < 26% of RAT ED THERMAL POWER THERMAL POWER l

High Setpoint - < 109% of RATED High Setpoint - < 110% of RATED THERMAL POWER TH ERMAL POWER -

3. Power Range, Neutron Flux, High < 5% of RAT ED ThlERMAL POWER with < 5.5% of RATED THERMAL POWER with Positive Rate a time constant > 2 second a t ime cons t ant > 2 second

4. Power Range, Neutron Flux, High < 5% of RATED THERMAL POWER with < 5.5% of RAT ED THERMAL POWER with Cegative Rate a time constant > 2 second a t ime cons t ant > 2 second

5. Intermediate Range, Neutron Flux < 25% of RATED THERMAL POWER < 30% of RATID THERMAL POWER

6. Source Range, Neutron Flux < 105 counts per seconc < l.3 x 105 counts per second

7. Overtemperature Delta T See Note 1 See Note 2

8. Overpower Delta T See Note 3 See Note 4

9. Pressur izer Pressure--Low > 1945 psig > 1935 psig

10. Pressurizer Pressure--High < 2385 psig < 2395 psig

11. Pressur izer Water Iavel--High < 92% of instrument span < 93% of instrument span

12. Loss of Flow > 92% of design flow per loop * > 91% of design flow per loop *

• Design flow is 88,500 gym per loop. .

CEAVER VALLEY UNIT 2

. Enclosure No; 2--.

TABLE 2.2-1 (Continued)

REACTOR TRIP SYSTDI INSTRUMBITATION TRIP SETPOINTS FUNCTIONAL UNIT TRIP SETPOINT ALIDWABLE VAIRES

13. Steam Generator Water Level--Iow-Low > 14.2% of narrow range instrument > 13.2% of narrow range instrument span-each steam generator span-each steam generator

14. Steam /Feedwater Flow Mismatch and Iow ~< 40% of full steam flow at RATED THERMAL < 42.5% of full steam flow at . RATED Steam Generator Water 'Invel POWER coincident with stean generator THERMAL POWER coincident with steam .

water level generator water level

> 25% of narrow range instrument span-- > 24% of narrow range instrument each steam generator span--each stems ' ge nerator

15. Undervoltage-Reactor Coolant Pumps 75% _+If of nominal bus voltage- > 70% of nominal bus voltage-each eachhus Tus -

16. Under frequency-Reactor Coolant Pumps > 58.0 H, -each bus > 57.5 H, -each bus

17. Turbine Trip

a. Auto Stop Oil Pressure 45 psig + 5 psig-l l b. Turbine Stop Valve > 1% open > 1% open

18. Safety Injection Input from ESF Not Applicable Not Applicable 1

19. Reactor Coolant Pump Breaker Not Applicable Not Applicable Position Trip BEAVER VALLEY UNIT 2 '2-7

c -

TABLE 2.2-1 (Continued)

REACTOR TRIP SYSTEM INSTRUMENTATION TRIP SETPOINTS -l NOTATION NOTE 1: OVERTEMPERATURE Delta T (1 + tgS) 1 (1 + t 4)

S 1 Delta T ( ) < Delta To K1-K2 .

[T ( )- TI ] + K3 - (P - PI ) - fh -(Delta I)

(1 + t 2)

S I + C3S (I + t SS) 1 + e68

~

Where: Delta T = Measured Delta T by RTD Manifold Instrumentation;-

l+tS 1

= Lead-lag compensator on measured Delta T; I + t2S ti, t2 = Time constants utilized in lead-lag controller for Delta T, t1 = 8 seconds, t2 = 3 seconds; 1

= Lag compensator on measured Delta T; I+tS 3 t3 = Time constants utilized in the lag compensator for Delta T, t3 = 0 seconds; Delta To = Indicated Delta T at RATED THERMAL POWER;

= 1.2261 for 3 loop operation Kg K2

= 0.01747; BEAVER VALLEY UNIT 2 2-9

i ,

Enclosure:

No.'2'

! TABLE 2.2-1 1 (Cont inued) l

. REACTOR TRI_P SYSTEM INSrRUMENTATION TRIP SETPOINTS ~

NOTATION (Cont inued)

Nor E 1: (Continued) i 1 + t4S

= The function generated by the lead-lag controller for T - dynamic compe ns at ion; .

'* 8 1 + tSS t4, t5 =

Time constants utilized in the lead-lag controller for T ,,8, t4 = 30 seconds , . t5 "

4 seconds; T = Average temperature. *F;

=

1 Lag compensator on measured T,y ;

1 + t6S t6 =

Time constant utilized in the measured T,y lag compensator, t6 = 0 seconds; ,

TI -

< -576.2*F (Nominal T avg at RKT ED THERMAL POWER);

K3

= 0.000823; P = Pressurizer pressure, psig; PI = 2235 psig (Nominal RCS operating pressure); and,

~

BEAVER VALLEY UNIT 2

Enclosure No; 2' TABLE 2.2-1 (Cont inued)

REACTOR TRIP SYSTEM INSTRUMENT _ATION TRIP SETPOINTS NOTATION (Cont inued)

NOTE 1: (Continued)

S = Laplace trans form operator, second-l; and f3 (Delta I) is a function of the -indicated difference between top and bottom detectors of the power-range-nucle ar ion chambers; with gains to be selected based on measured instrument response during plant startup tests such that:

(i) For at ' 9 between -34% and + 10% f -(Delta I) = 0, where q and q 8re Percent RAT ED THERMAL' POWER

~

b i b

in the top and bottom halves of the core respectively, and q + qb ts total THERMAL POWER in percent:

of RATED THERMAL POWER; (ii) For each percent that the magnitude of q qb exceeds -34% the Delta T Trip Setpoint shall be' automatically reduced by 1.439% of its value at RATED THERMAL POWER; and (iii) For each percent that the magnitude of q exceeds +10% the Delta T Trip Setpoint shall be automatically reduced by 1.789% of its value at t ~9b RAT ED THERMAL POWER.

NOTE 2: The channel's maximum Trip Setpoint shall not exceed its computed Trip Setpoint by more than 3.8%.

BEAVER VALLEY UNIT 2 2

,5 _ 5-.. .

_g . .  ; :, y; =;;: ,;; ' :::. _

~~ w V

. , Enclosure No. '2 TABLE 2.2 (Cont inued) . ,.

REACTOR TRIP SYSTEM INSTRUMBtr_ATION TRIP _SErPOIlfrS '

- N0 RATION (Cont inued)

NOT E 3: OVERPOWER De1ta T 1 + tgS I t7S 1 1 Delta T ( )( )< Delta To

~

K4~K5( )( )T-K6 [T ( ~ )-Til] - f2 (Delta T)

-1 + t2S l + C3S 1+t7S 1 +"t68 l' + C68 Where: Delta T = As defined in Note 1; I + tgS

= As defined .in Note 1; I+t28

= As defined in Note 1; -

tt, t2 1

= - As defined in Note 'l; I + t3S t3 = As de[ined in Note 1;

= As defined in Note 1; Delta TO K4

= 1.0851 2~

BEAVER VALLEY UNIT 2 ,

. Enclosure'Ns.l2

. TABLE 2.2-1 (Cont inued)

REACTOR TRIP SYSTEM INSTRUMENTATION TRIP _ SETPOINTS NOTAT ION (Cont inued)

NOT E 3: (cont inued)

K5

=

0.02/*F for increasing average ' temperature and 0 for decreasing average temperature; t7S

=

The function generated by the rate-lag controller. for T, ' dynamic compensation; t7 =

Time constants utilized in the rate-lag controller for T,yg, t7 = 10 seconds; 1

= As defined in Note 1; I + t6S

=

t6 As defined in Note I; K6

=

0.00ll5/*F for T > TIl and K6 = 0 for T < TII; T = As defined in Note 1; Til = As indicated T at RATED THERMAL POWER (Calibration temperature for Delta T instrumentat io$"8< 576.2*F);

2-13 BEAVER VALLEY UNIT 2

r < - -

3

,1 ,

. . Enclosure No. 2 ,

TABLE 2.2-I~

(Cont inued) .

REACTOR TRIP SYSTEM INSTRUMENTATION TRIP - SETPOIlff S NOTATION

- (Cont inued)

NOTE 3: (Continued) i S = As defined in Note 1; and f2 (Delta I) = 0 for all I a

~

NOT E 4: The channel's maximum Trip Setpoint shall not exceed its computed Trip Setpoint by.more than 3.0%.

BEAVER VALLEY UNIT 2 2-14

3

' TABLE.3.3-4 ENGINEERED SAFETY FEATURE' ACTUATION SYSTEM INSTRUMENTATION TRIP SETPOINTS Functional Unit Trip Setpoint -Allowable Values

1. SAFETY INJECTION AND FEEDWATER ISOLATION

a. Manual Initiation Not Applicable LNot Applicable

b. Automatic Actuation Logic Not Applicable Not Applicable:

e. Containment Pressure - High f 1.5 psig i 2.0.psig d.-Pressurizer Pressure - Low 1 1,875 psig > 1,866 psig

e. Steam Line Pressure - Low > 525 psig >'510 psig-steam line pressure- steam line pressure 1.1 SAFETY INJECTION - TRANSFER FROM INJECTION TO THE RECIRCULATION MODE

a. Automatic Actuation Logie Coincident with Not Applicable Not Applicable Safety Injection Signal

b. Refueling Water Storage Tank Level - Low 37'2" '37'2" + 1.9" BEAVER VALLEY UNIT 2 3/4 3-23

~..- -

Enclosure No.'2 TABLE 3.3-4 (Continued)

ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMENTATION TRIP SETPOINT S Functional Unit Trip Setpoint Allowable Values

2. CONTAINMENT SPRAY

c. Manual Initiat ion Not Applicable -- Not Applicable

b. Automatic Actuation Logic Not Applicable ' Not Applicable

c. Containment. Pressure - High-High i8.0psig .I 8.8 psig i

3, CONTAINMENT ISOLAT ION

a. Phase "A" Isolation

1) Manual Not Applicable - Not Applicable-

2) From Safety Injection Automatic Not Applicable Not Applicable Actuation Logic

b. Phase "B" Isolation

1) Manual Not Applicable _ Not Applicable

2) Automatic Actuation Logic Not Appliceble Not Applicable Actuation Logic

3) Containment Pressure - High High i 8.0 psig i 8.8'psig BEAVER VALLEY UNIT 2 3/4 3

-Enclosure No.'2 TABLE 3.3-4 (Continued)

ENGIN EERED SAFETY FEATURE ACrUATION SYSTEM INSrRUMENTATION TRIP SETPOINT S Functional Unit Trip Setpoint Allowable Values

4. Sr EAM LINE ISOLATION

a. Manual Not Applicable Not' Applicable L _

b. Automatic Actuation Log .ci Not Applicable ' Not Applicable L

c. Containment Pressure - Intermediate High High < 3.0 psig -< 3.8.psig

-d. Steam Line Pressure - Low > 525 psig > 510 psig steam line pressure steam line . pressure

e. High Steam Pressure Rate -100 psi -110 psi

5. TURBINE TRIP AND FEEDWATER ISOLATION

a. Steam Generator Water' Level - High-High < 75% of narrow range < 76% of- narrow range Ins tr ume nt span each Ins trume nt span each stean generator stema generator BEAVER VALLEY UNIT 2 3/4 3-25

cl Enclosura Ns. 2' '

TABLE 3.3-4 (Continued)

ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMDITATION TRIP SETPO_ INT S

Functional Unit '

Tr ip Setpoint - Allowable Values

6. LOSS OF : POWER

a. 1) 4.16kv Bnergency Bus Undervoltage 75% !jf of nominal' bus > 70% of nominal bus (Loss of Voltage) (Trip Feed) voltage with a 1 + 0.1 voltage with a 1 + 0.1 second time delay second time delay

2) 4.16kv Bnergency' Bus ( Start Diesel) 75%1If > 70% of nominal bus volta $e,of 20nominal cycles +bus 2 cycles voltage, 20. cycles + 2 cycles

b. 4.16kv Emergency Bus Undervoltage 90% [ff of nomiani bus > 89% of nominal bus (Degr aded Voltage) voltage with a 90 1 5 voltage with a 90 + 5 second time delay second time delay

c. 480v Emergency dus Undervoltage 90% 1}f of nominal bus > 89% of nominal bus (Degr aded Voltage) voltage with a 90 ~+ 5 . voltage with a 90 + 5 -

second time delay second time delay BEAVER VALLEY UNIT 2 3/4 3-26

g- ,

, -y - -

. q..

3 r

.. Enclosure No. 2-TABLE 3.3-4 (Continued) .

ENGINEERED SAFETY FEATURE ACTUATION SYSTEM INSTRUMBrrATION <

. TRI_P SETPOINT S ,

Functional Unit Trip Setpoint IAllowable Values

7. AUXILIARY FEEDWATER

a. Steam Generator Water Level - Low-Low > l4'j2%of narrow range >l3.2%of, narrow' range Ins tr ument span each Ins tr ume nt span each steam generator . steam generator

b. Undervoltage - RCP 75% !ff of ' nominal bus.. > 70% of nominal. RCP bus voltage voltage

c. S. I. See 1 ab ove ' ( al l S. I. .. Setpoints ) -

d. Turbine-Driven Auxiliary Feed Pump Disch pressure > 150 psig Disch pressure > 140 psig Discharge Pressure Low with Steam with stean inlet valves open with stean -. inlet . valves open Valves Open

e. Te ip of Main Feedwater Pumps Not Applicable Not Applicable

f. Snergency Bus Undervoltage 75% ll of nominal bus > 70% of nominal bus voltage voltage

8. ESF INTERLOCKS

a. P-4 N/A' N/A

b. P-ll . < 2000 psig < 2010 psig

- c. P-12 .(later), .(later)

BEAVER VALLEY UNIT 2 3/4 3-27

g -. ,

/

ENCLOSURE 1 JNRC. Draft SER Information' Request Section 7.2.2.4: -Trip Setpoints and. Margins-The _ staf f ' requested detailed information on the methodology used to estab--

-lish the Technical- Specification (TS) trip setpoints and allowable values for. the reactor protection system _(RPS) . (including reactor trip and engi-

~

neered - - s afe ty > fe ature channels) assumed to operate in the FSAR ' accident -

and transient analyses. This includes'the following information:

-(1) The. trip setpoint and allowable value for the TS.

(2) The safety -limits necessary. to protect the integrity .of the physical-barriers which guard against. uncontrolled release of radioactivity.

t (3) The . values ~ assign'ed to .' each ~ component of the combined ch annel error s allowance f. e . g . , modeling uncertainties, analytical' uncertainties, transient overshoot , . response time, trip unit setting accuracy, , test

. equipment accuracy, primary element accuracy, sensor drif t, nominal Land harsh environmental allowances, trip unit drift), the basis for these. values, and the method used to sum the individual errors. W ere zero:is assumed: for an error, a justification that the error is .negli-gible.should be provided.

(4)'The margin (i.e., the ~ dif ference between the safety limit and the setpoint-less the combined channel error allowance). *

~~

Response

'.(1) The recommended Nominal- Trip . Setpoints and the Allowable Values fo r .

the TS are as identified on Enclosure 2. Enclosure 2 is a :reproduc .

. t ion ~of Table . 2.2-1 for the RPS -trips and of Table 3.3-4 for the ESF actuations ' from the draf t Beaver Valley Power Station Unit 2 (BVPS-2)

TS.

(2) For those trips assumed to function in the accident analyses, the Safety Analysis Limit is as identified on Enclosures 3 and _4. ' Trips not assumed to function in any safety analyses are identified as "Not Used."

._ (3) The- values assigned to individual uncertainty components are as ide n-tified on Enclosures 3 and 4. The uncertainties are broken down into s component uncertainties using the standard Westinghouse nomenclature, which isidefined below:

-(a) Process Measurement Accuracy (PMA)

P Includes plant variable me'asurement errors up to but not including the sensor. Examples are the effect of fluid stratification on temperature measurements and the ef feet of changing fluid density on . level measurements. An' inaccuracy due to a non-ins trument effect.

-(b) Primary Element Accuracy (PEA),

This ' accuracy is defined as the accuracy exhibited by the primary

' element in the measurement of a process parameter. Used for ventures (flow), orifices, or elbow elements and accounts for noise.

(c) Sensor Allowable Deviation The - accuracy that can be expected in the field. It includes drift, temperature of fects, field calibration and, for the case of d/p transmitters, an allowance for the ef fect of static pressure variations. Sensor is interchangeable with transmitter.

The tolerances are as follows:

1) Reference (calibration) accuracy (SCA): This accuracy is the-SAMA reference accuracy as de fined in SAMA standard PMC-20 1973 2,

2) Temperature ef fect (STE): Base on nominal temperature coef fi-cient and a maximum assumed charge of 50*F.

3) Pressure effect (SPE): Usually calibrated out because pressure is constant. If not constant, a nominal value is used.

4) Drift (SD): Change in input-output relationship over a period of time at reference conditions.

(d) Environmental Allowance (EA)

This allowance is defined as the maximum channel ' deviation that is expected to occur solely due .to the ef fects of being exposed to a high energy line break environment. The ef fects of a high energy live break environment include temperature, pres sur e , humidity, radiation , chemical spray, acceleration, and vibration. This ,

error also includes allowances, whe re applicable, for reference leg heatup on level delta P sensors.

(e) Rack Allowable Deviation The. tolerances are as follows:

1) Rack . calibration accuracy (RCA): The accuracy that can be expected during a calibration at reference conditions. This accuracy is the SAMA reference accuracy as ' defined in SAMA standard PMC-20-1-19732 This includes all nodules in a rack.

For simple loops where a power supply (not used as a converter) is the only rack module, this accuracy may be ignored.

2) Rack environmental ef fects (RTE): Includes effects of tr.mpera-ture, humidity, volt age , and frequency ch ange s , of which temperature is the most significant.

.a, . . -- . , . - , -. - -- _. . . - - . . _ . . - . -

3) Comparator setting accuracy (RCSA): Assuming an exact elec-tronic input, note that the "channel accuracy" takes care of deviations from this ide al), the tolerance on the precision with which a comparator trip value can be set, within such practical constraints as time and ef fort expended in making the setting. RCSA is interchangeable with trip unit setting accuracy.

~The tolerances consider the following:

a) Fixed: setpoint with a single input: This assumes that comparator nonlinearities are compensated by the setpoint.

+

b) Dual input: An additional error must be added for compara-tor nonlinearities between two inputs.

4) Rack drif t- (instrument channel drif t) (RD): Change in . input-output relationship . over a period of time at reference conditions.

' The method used by Duquesne Light Company to calculate the trip.

setpoint meets the intent of References 1, 2 , and 3. The method-ology is as summarized below:

Safety Limit (Referen'ec 1)

A Allowable Value TS Reportable Occurrence Upper Setpoint Readjustment Limit Required Trip Setpoint No Readjusting Necessary Lower Setpoint Readj us tment Limit h Required Upper Band of Normal Operation Plant Availability Normal Operation T (' p- p 4 v - - + - me -.m-e--,um . e--g ,r >ymen > g y--y .g. w g -ip.,* - -we-- --- g -- ---

Comp _utation of Instrume_nt, Inaccuracies (II)*

11 = PMA + E A + l [PE A2 + SCA2 + SPE2 + STE2 .+ SD2 + RCA2 + RCSA2#

RTE 2'+'RD 2 ]1/2,*

. Computation of Nominal' Safety System Setting (hereaf ter refered to as

-Trip.Setpoint)

Trip Setpoint = Safety Limit.+. (II and Margin) x Span Where Trip. Setpoint = The ' desired setpoint for the vari ab le .

Initial c alibration . and subsequent. calibrations should reset the trip setpoint to this value.

Safety Limit ' = The trip setpoint value assumed in safety analyses (S.L.)

Margin = The - dif ference be tween the safe ty limit and . the trip setpoint le s s the II. The margin is a param-eter used to account- for unknown or inaccurately computed parameter accuracies.

+

-_ = de termined by conservative direction of safaty limit' Span = Span of instrument channel Computation of Allowable Value (AV)

AV = Trip Setpoint + [(RD + 0.5 x Margin) x Span]

• . Error .. values stated in terms of perce nt of span (unless indicated otherwise)

• • Square root of the som of the squares is a standard acceptable means for combining errors (see Reference 1)

REFERENCES:

1. ISA-567.04, - dated September, 1981, "Setpoints for Nuc le ar Safety-Related' Instrumentation Used in Nuclear Power Plants"

2. Scientific Apparatus Manu f acturers Association (SAMA),

S tandard PMC 20.1-1973, " Process Measurement and Control Terminology"

3. Regulatory Guide 1.105, Rev. 1, dated November 1976,

" Instrument Setpoints"

r; (4) The margin in the ' trip setpoint - (the '~dif ference between the . Safety

~

~ Analysis Limit and the~ Nominal Trip Setpoint less the combined channel error allowance) is a parameter used to account : for unknown or inaccu-rately . computed parameter accuracies. The minimum value of margin used was 0.35% of span.

.