B10698, Forwards Addl Info Re Measurement Uncertainties Per NRC .Process Equipment Installed During Cycle 4/5 Refueling Outage Provided Excellent Operating Characteristics of Modified Channels W/Minimal Drift

Forwards Addl Info Re Measurement Uncertainties Per NRC .Process Equipment Installed During Cycle 4/5 Refueling Outage Provided Excellent Operating Characteristics of Modified Channels W/Minimal Drift

ML20071B582
Person / Time
Site:	Millstone
Issue date:	02/22/1983
From:	Counsil W, Sears C NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	Clark R Office of Nuclear Reactor Regulation
References
B10698, TAC-48063, NUDOCS 8302280431
Download: ML20071B582 (28)

Text

_ - _ _ _ _ _ _ _ _ _ _ - _ _

General Offices e Selden Street, Berlin, Connecticut

,w ca cian to., me.ow. cow = P.O. BOX 270 9 **ma =useamS etsc'ac co*= HARTFORD, CONNECTICUT 06141-0270

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(203) 666-6911 k k J .s Ewnovcow=

, February 22,1983 Docket No. 50-336 B10698 Director of Nuclear Reactor Regulation Attn: Mr. Robert A. Clark, Chief Operating Reactors Branch #3 U. S. Nuclear Regulatory Commission Washington, D. C. 20555

References:

(1) W. G. Counsil letter to R. A. Clark dated, November 4,1982.

(2) R. A. Clark letter to W. G. Counsil dated, August 19,1982.

(3) W. G. Counsil letter to R. A. Clark dated, January 4,1983.

(4) W. G. Counsil letter to R. A. Clark dated, March 4,1982.

Gentlemen:

Millstone Nuclear Power Station, Unit No. 2 Request for AdditionalInformation, Measurement Uncertainties ,

Response to Question 4 In Reference (1), Northeast Nuclear Energy Company (NNECO) provided a partial response to the Staff's Reference (2) regt est for additional information concerning measurement uncertainties utilized in the Millstone Unit No. 2 safety analysis. Additional time was necessary to complete our responses to Questions 4 and 6 of Reference (2) and a mutually agreed upon schedule for providing these responses was documented in Reference (2) and updated in Reference (3). As per our Reference (3) agreement, NNECO hereby provides the response to Question 4 of Reference (2).

During the 1981-1982 (Cycle 4/5) refueling outage, NNECO instated new process equipment for several of the measurement channels addressed in the uncertainty analyses of References (1) and (4). Modifications included changes to the safety pressurizer pressure and steam generator pressure channels. Additionally, NNECO plans modifications to the feedwater differential pressure (delta-P) measurement channels as well as changes to hot and cold leg Reactor Coolant System temperature measurement channels. Details concerning the modifications are attached.

In providing justification of drif t allowances assumed for the measurement channels under review, NNECO provided plant historical drift data obtained from a number of previous calibration cycles. NNECO also included drift allowances for process equipment installed during the Cycle 4/5 refueling outage. Since this 8302280431 830222 PDR ADOCK 05000336 ,

P PDR

. _ . . - __ ._ . _ __ m _. . _ .

O equipment was installed, the operating characteristics of the modified channels have been excellent with' minimal drif t experienced.- In addition, available -

historical data obtained from existing and replaced hardware, where applicable',

has been used to justify drift allowances for new process equipment installed during the Cycle 4/5 outage and hardware to be installed in the upcoming Cycle 5/6 refueling outage. In this way, all drif t assumptions were verified to be conservative relative to a 95% probability criteria based on the evaluation' of s additional plant calibration data.

'Ihe process equipment modifications and revised drif t allowances necessitated the reanalysis of the' measurement uncertainties provided in Reference (4). As such, the response to Question 4 also arovides the results of the measurement uncertainty reanalysis of primary pres;.ure, primary temperature, core power j (LCO), primary flow, axial shape . Index (ASI) and core power -(LSSS). -The l calculated uncertainties are based on conservative calibration allowances and o drif t assumptions as discussed above. A comparison of the revised uncertainty analyses results with the measurement uncertainty assumptions utilized in the Millstone Unit' No. 2 reload analysis demonstrates. the additional conservation inherent in the reload analysis assumptions.

i Our response to question 4 is complete and attached. This information continues to upport the measurement uncertainties utilized in the Millstone Unit No. 2 safety analysis. The conclusions presented herein have not as yet been QA-verified.- This verification is expected to be completed shortly and you will be notified promptly when this process is done.

Concerning Reference (1), NNECO indicated that an evaluation of 'the feedwater measurement system was underway. The intent of this evaluation program is to identify possible areas of improvement in order to provide 'a more accurate -

) indication of feedwater temperature and thus a smaller core power uncertainty.

i At present this evaluation is nearly complete and NNECO plans to submit

] results of the program along with our response to Question 6 of Reference (2)in April,1983.

i We trust you will find this information responsive to the Reference (2) requests.

Very truly yours, 4

NORTHEAST NUCLEAR ENERGY COMPANY W O. C W. G. Counsil Senior Vice President b.

By: C. F. Sears j Vice President Nuclear and

Environmental Engineering

REQUEST FOR ADDITIONAL INFORMATION NORTHEAST NUCLEAR ENERGY COMPANY MILLSTONE NUCLEAR POWER STATION, UNIT NO. 2 DOCKET 50-336 OUESTION 4

'Information is supplied in Appendix A' to define instrument span drifts between calibrations. The data supplied are too few to support the assumption of 28' limit. Provide further historical data to confirm the 2r assumption.

1. Background Question 1 of Reference 1 provided the results of a measurement uncertainty analysis for primary pressure, primary temperature, core power (LCO),' primary flow, axial shape index (ASI), and core power (LSSS). -

Reference 2 provided the results of a reanalysis of the core power (LCO) and primary flow uncertainties to determine the effects of certain dependent error contributions.. These uncertainty analyses were done -to justify the uncertainties assumed in the Millstone Point Unit 2 Reload Analyses.

This question requests additional information to justify the drift uncertainties assumed in the above referenced analyses. Recently, Northeast Nuclear Energy Company installed new process equipment for some of the measurement channels under - review. Additional process equipment replacements are scheduled to be made during the Cycle 5/6 refueling outage. These process equipment changes necessitated a

-reanalysis of the above mentioned uncertainties.

Section 2 of this response will provide the results of the measurement uncertainty analysis including the effects of the process equipment change outs. Section 3 will justify the drift values. assumed in this analysis.

Justification is based on 'a review'of plant historical drift data obtained from a number of previous calibration cycles.. To date, operatin characteristics of channel modifications performed during the Cycle 4/g5 refueling outage have been excellent with minimal drift experienced. It is expected that further process equipment replacements will exhibit similiar operating characteristics meeting and in most cases . exceeding the performance of the replaced equipment. Therefore, the historical drift data used to justify drift allowances for-new equipment is conservatively bounding.

2.. Measurement Uncertainties This section provides the results of the measurement uncertainty reanalysis of - primary pressure, primary tempe,ature, core power (LCO), primary flow, axial shape index (ASI), and core power (LSSS). Figures 1-7 provide the block diagrams for those measurement channels under investigation. A listing of the equipment as well as the calibration accuracy, drift, range

. and span are specified on the block diagrams. Tables 1-11 summarize the

a' calculations of the individual measurement channel uncertainties as well as

, the overall uncertainties in core power (LCO), primary flow, ASI, and neutron power calibration. Table 13 provides a comparison of . the uncertainties calculated in this analysis and the uncertainties utilized in the Millstone Unit 2 Reload Analyses.

The attached figures and tables are similar to those previously provided in References I and 2. Figures 2, 3, 4, 5, and 7 provide the block. diagrams

for those measurement channels whose process equipment has been or will be changed during the Cycle 5/6 refueling outage scheduled for late-May, 1983. As noted on these figures, the Foxboro EllGM pressure transmitters are replaced with LOCA qualified Foxboro NEllGM transmitters. The main feedwater AP transmitters will be replaced with redundant Foxboro 823 o P transmitters for each of the ' two main feedwater flow measurement channels. For each train, either4P transmitter may be selected for input to the computer calorimetric core power calculation.

The redundant A P transmitters have been provided to increase the reliability of the main feedwater flow measurement. Foxboro SPEC 200 process equipment is provided to process the pressure and A P transmitter.

current output. This equipment consists of current to voltage (1/V) and voltage to current (V/I) converter rack modules. The processed current signal is converted to a voltage signal across a precision 250 ohm resistor which is then provided to either the computer or RPS.

! Figures 3 and 4 provide the : block diagrams for the new primary temperature measurement channels. - The primary sensor is a platinum RTD provided by the Weed Instrument Co. The Foxboro SPEC 200 process equipment consists of platinum resistance to voltage (R/V), and V/1 converter rack modules. The processed cu rent signal is converted to a voltage signal across a precision 250 ohm ren.istor which is then provided to either the RPS or to the computer for the primary flow calculation.

Figures 1 and 6 provide the block diagrams for the measurement channels ,

that are unaffected by the process equipment changeouts. The pressurizer

[. pressure channel shown in Figure 1 is used in the computer calculation of t primary flow. The main feedwater temperature channel shown in Figure 6 is used in the computer calculation of calorimetric core power.

The RTD accuracies . utilized in this analysis include the calibration accuracy as well as the small errors resulting from joule heating, friction heating, and stem conduction. The 100 ohm resistor error and computer uncertainties were previously discussed in Reference 1. It must be noted that the- Reference 1 and 2 analyses assumed an overly conservative calibration accuracy of 14% (1240F) for the main feedwater temperature i RTD sensor. As shown on Figure 6, the appropriate calibration accuracy for this type of RTD is 1 60F 1 which corresponds to 127% of span. This

! results in a slightly decreased overall channel uncertainty compared with the channel uncertainty utilized in the Reference 1 and 2 analyses.

The transmitter calibration and temperature effects uncertainties as well 4

as the feedwater venturi calibration uncertainties were previously 3-ce 3-a-n,, - -c.. . , , .y y o n -i. =+-,y., .----n.y,-.,.--g---.w ,,,,----,w,-,, w,,-.v.,y,, , .y %,, (E_,,,y- mm-,.-,.- +-,,--,----,.,.,-r------~ ,--,-.--,-,,,,,,--r-

_ _ ._ _ ~ . . _ _ .

a discussed in Reference 1. The pressurizer pressure (safety channels),

steam pressure and feedwater4P transmitter replacements do not effect these uncertainties.

The ' calibration accuracies for the Foxboro SPEC 200 rack modules are shown on the block diagrams for those channels utilizing Foxboro process equipment. It should be noted that for those channels which have more

' than one rack module mounted in series a reference calibration signal is input at the front end of the channel and all modules are " tuned" to the -

reference signal. . For this type of calibration, the rack module and precision resistor uncertainties need not be considered individually. The i Foxboro SPEC 200 rack calibration uncertainties utilized in this analysis

- bound any uncertainties associated with the "as left" setting tolerance as well as the small uncertainties associated with calibration equipment.

All drift uncertainties utilized in this analysis are justified in Section 3 of this response.

Tables 1-11 summarize the results of the calculation of the overall uncertainties for the parameters under investigation. The calculational methodology is the same as that provided in References 1 and 2. It must be noted that the calculation of the primary flow uncertainty summarized on Table 9 utilized slightly modified sensitivity factors to relate primary temperature and pressure uncertainties to flow uncertainties. The temperature measurement uncertainties result in enthalpy uncertainties equivalent to the following re. actor coolant flow i.ncertainties:

1 22% nominal flow /0F (THOT) i .95%

1 nominal flow /0F (TCOLD)

The 1 330F uncertainty in THOT and TCOLD results in the following reactor coolant flow uncertainties:

1 73% nominal flow (THOT) 1 65% nominal flow (TCOLD)

As discussed in Reference 1, an additional uncertainty of 1 50F is assumed to account for hot leg temperature gradient effects which results in a i 1.1% flow uncertainty.

The pressurizer pressure uncertainty results in enthalpy uncertainties equivalent to the following reactor coolant flow uncertainties

+ .0067% nominal flow / psi (hh)

.0022% nominal flow / psi (hc)

A +19 psi uncertainty in the primary pressure measurement results in the following reactor coolant flow uncertainties:

2

_4_.

+ .13% nominal flow (hh)

.042% nominal flow (hc)

Since the pressure errors are dependent, they are added to give an overall 1 encertainty of 2 088% nominal flow. The overall pressure uncertainty can be' combined statistically-' with the temperature and core power error contributions using the RMS method since the overall pressure uncertainty-is independent with . respect to these errors. ' As noted on Table 9, the reactor coolant flow uncertainty is 1238% of nominal flow.

Recent primary flow calculations performed at Millstone Unit 2 indicated a nominal measured flow of 118.5% of the design flow of 324800 GPM. The Reference 1 and 2 analyses .were based.on ar earlier measured nominal flow of 123.6% of design. The reduction in the nominal measured flow is attributed to a number of steam generator tube plugging operations performed at Millstone Unit 2 which slightly increased the overall primary coolant loop resistance. The ~ decrease in loop flow resulted in a slight variation in primary temperatures which resulted in the slight -

modifications to the above mentioned sensitivity factors.

It is preferable to express the reactor coolant flow uncertainty as a percent of the design volume flowrate. Multiplying the nominal flow uncertainty by 1.185 gives a reactor coolant flow uncertainty of 1 282% of design flow.

Tables 10 and 11 summarize the caMulation of -overall error in ASI calibration and neutron power calibration. - Reference 1 ' provided a description of the methodology to determine the overall errors. The only difference between the Reference 1 analysis and this response is the value of core power uncertainty and the ASI and neutron power drift allowances.

~

Table 9 provides the overall calorimetric core power uncertainty. All drift allowances utilized in this analysis are justified in the following section.

3. Justification of Drift Allowances In order to justify the drift allowances assumed in this analysis, a statistical evaluation was performed on the calibration data for those measurement channels under investigation. Drift is determined from the difference between "as found" and "as left" checks between calibration cycles.

Data for the Foxboro EllGM pressurizer (safety and control) and steam generator (safety) pressure transmitters were lumped together. These transmitters are recalibrated during- refueling outages. The drift value.

obtained from this data is applied to those pressure channels .which incorporate the new Foxboro ~ NEllGM transmitters since these transmitters are expected to exhibit less drif t than the Foxboro EllGM.

Drift data obtained from the GE MAC 555 feedwater A P transmitter calibration checks is used to estimate the drift for the new Foxboro 823 A P transmitters. These transmitters are calibrated quarterly. All historical

t L drif t data was used to justify the feedwater temperature transmitter drift assumption.

The Foxboro SPEC 200 rack module drift' assumption is justified from data obtained from-the monthly calibration checks'for the new pressurizer and

steam generator pressure channels installed during the Cycle 4/5 refueling-outage. This data is also used to justify the rack module drift associated with those channels to be installed during the Cycle 5/6 refueling outage.

The excore ASI measurement is calibrated to the incore value on a monthly basis.while the neutron power measurement determined from the excore neutron flux detectors is calibrated to the calorimetric core power

! reference value on a daily basis.

i A 95% probability. criteria is used to justify the drift limits used in this analysis. A review' of the calibration data' obtained for the above mentioned channels indicates that a normal or Gaussian distribution provides the best prediction of the actual distribution of the drift data.

, For a normal distribution, the 95% probability limits are defined by 1.96.

times the standard deviation of the data distribution.

Table 12 summarizes the results of the statistical evaluction of the drift data distributions. The standard deviation,' S, is calculated from the drif t data using a population parameter of "N-1", where N is the number of data points. The standard deviation for ASI and neutron power calibration is

!- given in terms of ASI units and percent power, respectively. The standard deviation for the remaining channels is given in~ percent of span. In all l cases the analysis assumptions are greater than the 95% probability limits

defined by the data. -

4. Conclusion Table 13 provides a comparison of the -uncertainties calculated in this analysis and the uncertainties utilized in' the Millstone Unit 2 Reload Analysis. The calculated uncertainties are based on conservative calibration allowances and drift assumptions. All drift assumptions were

, verified to be conservative relative to a 95% probability criteria based on an evaluation of additional plant calibration data.

Axial Shape Index and LSSS Power uncertainties are made up of a number of components which include measurement uncertainties ' as well as calculational allowances. This analysis only addressed the calibration / drift-error component. The ASI calibration / drift allowance is 101 asiu. The LSSS Power calibration / drift allowance is 12% power. The results shown on Tables 10 and 11 justify these allowances.

The results of the comparison shown on Table 13, therefore, justify the applicability and conservatism of the measurement uncertainties utilized in

the Millstone Unit 2 Reload Analysis.

t.

. . - , -n, .- - , . , ,

f j 4

5. References

1. W. G. Counsil to R. A.' Clar k, " Millstone Unit 2 Measurement Uncertainties," March 4,1982. ,.

2. W. G. Counsil to -R. A. Clark, " Millstone Unit 2 - Additional Information, Measurement Uncertainties," November 4,1982.

i 6

I t

1

i FIGURE 1-l Pressurizer Pressure Span 1000 psi (Control _ Channels) Range 1500-2500 psia ,

)

Transmitter -+ .5% Calibration Foxboro EllGM ][.5%TemperatureEffects

+ 1.75% Drift Resistor ~'+ .0125%

(100 ohm)

Computer

(') + .2%

Errors in percent of span l

l

FIGURE 2 Pressurizer Pressure Span 1000 psi (Safety Channels) Range-1500-2500 psia Transmitter + .5% Calibration Foxboro NE11GM i.5%'TemperatureEffects

+ 1.75% Drift I/V Converter Foxboro N-2AI-I2V V/I Converter Foxboro N-2A0-VAI

)

./

+ .5% Calibration 1 5% Drift Resistor (250 ohm)

Bistable Trip Unit O.

Errors in percent span

FIGURE 3 TCOLD (Safety Channels) Span 150 F Range 465-615 F RTD-Weed -1 1% Calibration SP612 2BC4C1800 0 R/V Converter Foxboro N-2AI-P2V Selector Foxboro N-2AP + 1 25% Calibration SS1 i .5% Drift i .25% Calibration i .5% Drift O V/I Converter (

Foxboro N-2A0-VAI (

Resistors C (250 ohm) 1/

1 2% computer RPS Errors in percent span

FIGURE 4 TH0T (Safety Channels) Span 150 F Range 515-665 F

+ .1% RTD - Weed + .1% Calibration SP612-2BC4C1800 R/V Converter Foxboro N-2AI-P2V SUM & AVE Foxboro N-2AP + SUM i .25% Calibratioa 1 5% Drift i .25% Calibrati an V/I Converter Foxboro N-2AO-VAI 1 5% Drift O Resistor (250 ohm) v i .2% computer Errors in percent span r -- ~ ,

FIGURE 5 Main Feedwater a P Span 100% AP Range 0-100% AP

. t v (3 + .25% of flow Lab Calibration UM. i l + .25% of flow Installation Allowance

(

l Un r al Calibration Coefficient' e V 1 1% of flow Extrapolation-Tube Transmitters + .5% Calibration Foxboro 823 1 5% Temperature Effects i 1.0% Drift I/V Converter Foxboro N-2AI-I2V

+ .5% Calibration 7 switch 1 5% Drift i V/I Converter Foxboro N-2A0-VAI Resistor (

l (250 ohm) (

Computer + .2%

Note: All errors in percent of a P span unless specified otherwise l

FIGURE 6 Feedwater Temperature Span 600 F Range 0-600 F RTD 1 1.6 F 0 Tp = 435 F Rosem7unt 104MD 1 27%

Transmitter + .5% Calibration Rosemount 442ARG ][1.5% Drift Resistor ~~+ .0125%

(100 ohm) t Computer i .2%

Errors in percent span i I I

L _ _ _ _ _ _ _ _ _ _ _ _ ._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ l

' FIGURE 7 Steam Pressure Span 1000 psi Range 0-1000 psia Transmitter i .5% Calibration Foxboro NE11GM i .5% Temperature Effects i 1.75% Drift I/V Converter Foxboro N-2AI-I2V V/I Converter Foxboro N-2A0-VAI

)

/

-+ .5% Calibration

.5% Drift Resistor )/

(250 ohm)

Computer i .2%

Errors in percent span

. TABLE 1 1

Errors in Pressurizer Pressure (Control Channels) P-100 X, Y Span 1000 psi Range 1500-2500 psia

1. Transmitter (Foxboro E11GM)

Calibration' Accuracy + .5%

Temperature Effects + .5%

Drift + 1.75%

i

2. Precision Resistor (100 ohm) + .0125%

3. Computer. Accuracy + .2%

f 9

Total Error =

[~ .52 + .52 + 1.752 + .01252 + .22 31

= + 1.9% of span

= + 19. psi

- Errors in percent span f

4

TABLE 2 Errors in Pressurizer Pressure (Safety Channels)- P-102 A,B,C,D Span 1000. psi Range 1500-2500 psi

1. Transmitter (FoxboroNE11GM)

Calibration Accuracy + .5%

Temperature Effects + .5%

Drift + 1.75%-

2. Foxboro SPEC 200 Rack Modules (Including Bistable Trip Unit)

Calibration + .5%

Drift + .5%

Total Error =

[ .52 + .52 + 1.752 + .52 + .52 31

= + 2.02% of span

= + 20.2 psi Errors in percent span I

b 4

l.

-TABLE 3 Errors in TCOLD (Safety Channels) T-112C. A,B,C,D

.T-122C 'A,B,C,D Span 150 F Range 465-615 F' 4-

1. RTD (Weed SP612 2BC4C1800) Calibration .

.1%

f

2. Foxboro SPEC 200 Rack Modules

! Calibration + .25%

Drift + .5%

3. ' Computer 3,. 2%

Error (to RPS) = [ .12 + .252 + .52 ]E = j,.57% span-

= + .86 F Error in TCOLD Associated with RV Flow Determination:

1 Error (tocomputer) =

[ .12 + .252 + .52 + .22 3

= + .61% span

+ .92 F l

l -Error (Average of 8 TCOLD measurements) = + .61%

l Y8' l = + .22%

' = + .33 F i Errors in percent span l

i l

TABLE 4 t

Errors in TH0T (Safety Channels) T-112H A,B,C,D~

T-122H A,B,C,D

~ Span 150 F Range 515-665 F

1. RTD (Weed SP612 2BC4C1800) Calibration .1%

2. Foxboro SPEC 200 Rack Modules Calibration i .25%

Drift .5%

3. Computer .2%

Error (to RPS)- = [ .12 + .252 + .52 gi = .57% span

= .86 F Error in TH0T associated with RV flow determination:

1 Error (tocomputer) =

[ .12 + .252 + .52 + .22 3= .61% span

= .92 F Srror (Average of 8 TH0T measurements) = .61%

4 vf 8

= .22%

• = .33 F Errors in percent span I

TABLE 5 Errors in Main Feedwater AP. F-5268, F-5269

-Span 100% AP Range 0-100% AP

1. BIF Universal Venturi Tube i .25% of nominal flow

~

j- Laboratory Calibration Installation Allowance' i .25% of nominal flow.

Calibration Coefficient Extrapolation Allowance i .1% of nominal flow

2. AP Transmitter (Foxboro823) f i Calibration Accuracy .5%

Temperature Effects .5%

Drift i 1.0%

3. Foxboro SPEC 200 Rack Modules I

i Calibration .5%

j Drift i .5%

i

4. Computer .2%

1 Errors in Venturi calibration coefficient (K) = [ .252 + .252 + .12 3 4- = .37% of nominal flow ,

I Errors in Venturi AP measurement = [ .52 + .52+ 12 + .52 + .52 + .2 321

j. = i 1.43% of AP span The AP measurement error is converted to percent of nominal measured feed-

water flow at 100% power conditions by multiplying by a factor of .567.

L AP measurement error = .567 x ( 1.43% AP span)

[

= .81% of nominal flow NOTE: Individual component errors are in percent of AP span unless specified

-_._Lotherwise _ . ,, _ . ___,__ , _ __ , _ _ , . . ._. _ _ _ . __

TABLE 6 Errors in Feedwater Temperature T-5262 Span 600 F Range 0-600 F

1. RTD (Rosemount 104MD) Calibration i 1.6 F 0 Tp = 435

.27%

< 2. Transmitter (Rosemount 442 ARG)

Calibration Accuracy .5%

Drift 1.5%

3. Precision Resistor (100 ohm) .0125%

4. Computer Accuracy .2%

1 j

Total Error =

[ .27 + .52 + 1.52 + .01252 + .22 3

= 1 1.62% of span

= 1 9.72 F j

f Errors in percent span T

TABLE 7 Errors in Steam Generator Pressure P-1013 A P-1023 A

Span 1000 psi i Range 0-1000 psia 1

1. Transmitter (FoxboroNE11GM)

Calibration Accuracy .5%

Temperature Effects .5%

Drift 1.75%

2. Foxboro SPEC 200 Rack Modules Calibration .5%

Drift ' .5%

3. Computer . 2%

2 Error =

[ .52 + .52 + 1.752 + .52 + .52 + .2 _31

= 2.03% span

= 20.3 psi Errors in percent span I

e- + , , -

-,..--r- . .-,.--v.<w- -er-n,. , , , - - , , , ,- ~- ., ,,n-,-- ,-, , --m-- e-

TABLE 8 Errors in Steam Generator Thermal Output and Core Thermal Power Errors in Steam Generator Thermal Output Error Component Error (% SG Thermal Output)

-1. Independent Errors

- Due to venturi calibration coefficient (K) .37%

- Due to venturi area expansion factor (F) i .034%

(linear tllermal expansion coefficientuncertainty)

- Due to AP measurement .81%

Subtotal of Independent Errors-(RMS) i .9%

2. Errors due to steam Pressure (Ps )

.091%

- Error in feedwater steam enthalpy enthalp (h))(hf) -

.002%

- Error in feedwater density (Pf) + .008%

Total of PsErrors i .085%

3. Errors Due to Feedwater Temperature (Tf)

- Error in feedwater enthalpy (hp) - 1.37%

- Error in feedwater density (Pf) - ~.41%

l - Error in F a + .02%

Total of Tf Errors 1.76%

2 f 9 + ,f l.76 -+ 1.76\2 - 1

% Core Thermal Power Uncertainty =

2 t%

2j

+2 j.085

( 2j i 2 2j_

l l -

1.87%

The t 1.87% uncertainty is the error in core thermal power expressed as a percent of the nominal measured core thermal power of 2700 MW.

l l

l 1

l

TABLE 9 Errors in Reactor Coolant Flow Detennination Error Component Error (% Nominal Flow)

1. Core Thermal Power Uncertainty. (+ 1.87%) 1.87%

2. Error Due to Average TH0T Error in hot leg enthalpy (hh) .73%

3. Error Due to Temperature Gradient Effect Error in hot leg enthalpy (hh) 1.1%

4. Error Due to Average TCOLD Erro- in cold leg enthalpy (hc.) .65%

5. Error Due to Pressurizer Pressure (Pp )

Error in hot leg enthalpy (h ) + .13%

Error in cold leg enthalpy h(hc) .042%

Total of P errors .088%

p TOTAL ERROR (RMS) 2.38%

Typical measured flow is 118.5% of the design flow of 324800 GPM, therefore:

% Reactor Coolant Flow Uncertainty = 1.185 x 2.38%

= 2.82 % of design flow

TABLE 10' i

a Error in Axial shape Index Due to Calibration of Excore Detector. Voltage Signals Error Contribution Error (asiu)

1. Error in upper detector voltage (U) calibration -i. 00096 l

2. Error in lower detector voltage (L) calibration i .0008

3. Axial Shape Index drift allowance .00891

4. Total Error (RSS) i .009 I

l

TABLE 11 Error in Nuclear Power and AT Power Calibration to Calorimetric Power Error Contribution Error (% Power)

1. Calorimetric Power Uncertainty 1.87

2. RPS Digital Panel Meter (Newport Series 2000-3) .06

3. Calibration Setting Tolerance -

.1

4. Drift Allowance .5

5. Total Error (RSS) 1.94 i

f t..

TABLE 12 JUSTIFICATION OF DRIFT ASSUMPTIONS EQUIPMENT # DRIFT STANDARD 95% PROBABILITY ANALYSIS-DATA POINTS DEVIATION LIMITS -ASSUMPTION (S) (1.96S) s Pressure Transmitters 39 .88% 1.73% 1.75%

! Feedwater a P Transmitters 8 .36% .71% .

1.0%

Feedwater Temperature Transmitter. 10 .61% i 1.196%' 1.5%

, Foxboro SPEC E00 Rack Modules 84 .18% i .353% i .5%

! ASI' Calibration 140 .0042.asiu i .0083 asiu -

.00891 asiu Neutron Power Calibration 57 .132% .26% - . 5%

9 J

l l

4

r -

T

.O TABLE 13 Comparison of Uncertainties s

Uncertainties Utilized Parameter Calculated Uncertainties in Reload Analyses Pressure i 20.2 psi i 22 psi -

Temperature i .86*F 1 2*F Power (LCO) i 1.87% i 2%

Primary Flow i 2.82% i 4%

Axial Shape Index 4 i .06 asiu i .06 asiu 4

Power (LSSS) < 1 5%- 5%