ML19343D293

Forwards Results of 31 Effective Full Power Days Measurement for Uncertainty Factors & Details of Methodology Employed in Determination of Peaking Factors Uncertainties.Methodology Details Withheld (Ref 10CFR2.790)

ML19343D293
Person / Time
Site:	Fort Calhoun
Issue date:	04/24/1981
From:	William Jones OMAHA PUBLIC POWER DISTRICT
To:	Trammell C Office of Nuclear Reactor Regulation
Shared Package
ML19260H088	List: ML19343D293
References
NUDOCS 8105040202
Download: ML19343D293 (32)

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Omaha Public Power District -

1623 MARNEy e OMAHA, NESMASMA 68102 a TELEPHONE S36 4000 AREA CODE 402 April 24, 1981 b *< 42 'A b\M Mr. Charles M. Tramell g .

Project Manager T y '

U. S. Nuclear Regulatory Comission 29 Office of Nuclear Reactor Regulation , e Division of Licensing - k s Operating Reactors Branch No. 3 D

Washington, D.C. 20555 ['6'

Reference:

Docket No. 50-285

Dear Mr. Tramell:

The Comission's letter to the Omaha Public Power District dated February 2,1981, forwarded Amendment No. 55 to the Fort Calhoun Station Facility Operating License. This amendment added Interim Special Techni-cal Specification (ISTS) 6.4, allowing continued operation with less than 75',' operable incore nuclear detectors. The Comission's Safety Evaluation of the amendment specified that the District furnish the NRC Project Manager with the results of the 31 EFPD measurement for un-certainty factors required by ISTS 6.4. Attachment 1 sumarizes the results of the measurement. Attachment 2 details the methodology em-ployed in the determination of peaking factor uncertainties.

Please note that Attachment 2 is a proprietary Combustion Engi-neering report and includes the affadavit supporting a request for withholding this information from public disclosure, pursuant to 10 CFR Chapter 2.790, paragraph (b)(4).

Sincerely,

', . . -- .n ~ -- - .2=

W. C. Jones Division Manager Production Operations WCJ/KJM/TLP:jm Attach.nents cc: Mr. Dennis Kelley-NRC l LeBoeuf, Lamb, Leiby & MacRae l

8105040 W f

l 1

.. s ATTACHMENT I EVALUATION OF PEAKING UNCERTAINTIES With less than 75% of the incore detector strings operable. Interim Special Technical Specification (ISTS) 6.4 requires that the total

- planar radial peaking factor uncertainty (U x v), the total integrated radial peakin R uncertainty (g Uq factor uncertainty

) be assessed every(U 31 ), and the EFPD. total peaking Attachment factor 2 recomends that the previous total uncertainties be increased by 1% to:

7% for FR 8% for Fxy, Fq An analysis perfonned by Combustion Engineering, Inc. showed that a failure of up to 80% of all incere detectors resulted in an additional uncertainty of less than 1%, so the use of a 1% increase in the peaking factor uncertainties as above is conservative.

Attachment 2 also recommends that. rather than assess the total uncertainties every 31 EFPD, the measured pooled uncertainties should be calculated and compared to the pooled limit values in Table III (of this a ttachment) . If the measured pooled uncertainties are less than the pooled limit values, then the overall uncertainties are in compliance.

In addition to assessing the peaking factor uncertainties every 31 EFPO's, factors peaking ISTS 6.4F requires tgat the CECOR measured untilted radial M and F be corrected and be shown to be within their respective hechnicaiySpecification limits of 1.52 and 1.57. The correction is performed by:

FR = 1.01 FR Fxy = 1.01 FxyM On January 26, 1981, the limit of having less than 75% of the strings operable was reached. On February 2,1981, ISTS 6.4 was issued, with a Cycle 6 burnup of 5830 MWD /MTU. At the time of ISTS implement-ation, the measured pooled uncertainties and peaking factors were less than the upper limits. Thirty-one EFPD corresponds to 965 MWD /MTU, so the next required surveillance would be at 6795 MWD /MTU. This sur-veillance was performed at 6500 MWD /MTU and the measured pooled values SF and Sq found to be of lessSFxEa,n t t$e,ir respective limits of0.02690, 0.01905, 0.03210, 0.02691, and 0.02693 which are and 0.03211 .

Table 1 shows a continuation of Table II from Attachment 2; i.e. ,

measured pooled uncertainties for FR, Fxy, and Fq versus burnup. The values of cr; and F xy were 1.43 and 1.47 which have margins 0.09 and 0.10 to their Technical Specification limits.

=

l and F versusFigures 1 and fuel burnup for 2Cycle show 6. nlots of the measured FxyThe triangularstep change upwt points to circular points) indicates the change to less than 75% of the strings operable and, consequently, the application of a 1.01 multiplier on the CECOR Fx v M and FRM values. These data show decreasing pe.sking factor values with fuel burnup and increasing margins to Technical Specification limits. This trend is expected to continue for the re-mainder of Cycle 6.

Figures 3, 4, and 5 show plots of Sr: SF , and Sp versus Cycle 6 burnup. These values show a decreasing tN5n,d wkich is c8nsistent with the failure of older detectors (with increased sensitivity uncertainties) and are less than the pooled limit values since the issuance of ISTS 6.4.

TABLE I .

ft. Calhoun Unit 1 Cycla 6 .

Summary of Measurement Uncertainty fer All Tinepoints - .

SFXY ,

Burnup Level 1 N(1)-1 Level 2 N(2)-1 Level 3 N(3)-1 Level 4 N(4)-1

.03450 26 .02848 27 .03459 26 .03124 24 300 MWD /T 500 MWD /T .03825 26 .02928 27 .03335 26 .03141 24

.03388 25 .03226 27 .03959 25 .03440 23 1000 MWD /T 2000 MWD /T .02619 25 .02893 27 .03698 23 .03130 22 3000 MWD /T .02745 24 .02657 26 .02901 21 .03002 21

.0270) 24 .02948 24 .03501 21 .03208 20 4000 MWD /T 5000 MWD /T .02639 24 .03046 24 .03130 19 .03178 19 5800 MWD /T .02594 24 .02807 22 .03144 19 .02652 18 6500 MWD /T 02773 23 .02480 19 .02752 19 .02754 16 SFXY Burnup Pooled NnEC SFQ NDEG SFR f4DEG 300 MWD /T .03229 103 .03228 103 .02692 22 500 MWD /T .03324 103 .03315 103 .02675 22 1000 MWD /T .03510 100 .03518 100 .03023 19 2000 MWD /T .03092 97 .03098 97 .02578 18 3000 MWD /T .02817 92 .02818 92 .02361 14 495 .03211 495 .02691 95 .-

Pooled .03210 4000 MWD /T .03085 89 .03079 89 .02772 12 5000 MWD /T .02988 86 .02982 86 .02341 11 5800 MWD /T .02797 83 .02796 83 .0E183 11 6500 MWD /T .02690 77 .02693 77 .01905 9 CYCLE BURituP (MWD /MTU) i

Figure 3 ,

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Fort Calhoun Cycle 6 Measured Unrodded Radial Peaking Factor ,

Uncertainty, S fxy -

3.50 . O vs Cye'.e Burnup 3.40 _

3.30 _

O

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c 3.20 ..

B .

M 3.10 .

o o cn

.5 3.00 o G

ET 2.90 2

2.80 ..

O o "E

ff 2.70 o Eb y 2.60

}R 2.50 .

j 2.40 _

2.30 -

2.20 .

2.10 .

2.00 ..

1.90 ' ' ' ' ' ' ' ' '

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10,000. 11,000 4

Cycle Burnup (MWD / Mill)

Figure 4 ,

O F rt Calhoun Cycle 6 Heasured Total Peaking Factor Uncertainty, Srq ,

vs Cycle Burnup -

3.50 3.40

. O 3.30 -o .

p 3.20 -

3.10 O s

8 O g 3.00 o

y 2.90 .

a*n O y.!!  ?.90 ..

5e p 5 2 ~ 2.70 3 2.60 e

u 2.50 _

E

=>

$ 2.40 -

l!

2.30 .

2.20 -

2.10 .

2.00 1.90 ' ' ' ' ' ' ' ' ' '

l 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10,000 11,000 Cycle Burnup (MWD /f1TU)

Figure 5 -

Fort Calhoun Cycle 6 Measured Integrated Radial Peaking Factor Uncertainty SFR

• 3.30 . vs Cycle Burnup 3.20 p 3.10 .

{g- 3.00 _

O

=a 2.90 _

s.

S o 2.co E O E 2.70 L= == -0 0 E~ 2.60 -

o

%E E* 2.50 -

E v 2.40 3 0 2 O.

g 2.30 -

c

[ 2.20 -

o ,

e .

R e

2.10 -

E 2.00 -

I -~

1.90 -

O 1.80 -

! 1.70 e a ' ' ' ' ' ' * * '

0 1000 2000 3000 4000 5000 6000 1000 8000 9000 10,000 11,000 Cycle Burnup (MWD /11TU)

ATTACHMENT 2 AFFIDAVIT PURSUANT TO 10 CFR 2.790 Combustion Engineering, Inc.- )

State of Connecticut )

County of. Hartford ) SS.:

I, P. L. McGill depose ard say that I am the Vice President, Commercial of Combustion Engineering, Inc., duly authorized to make this affidavit, and have reviewed or caused to have reviewed the information which is identified as propric-tary and referenced in the paragraph immediately below. I am submitting this affidavit in confomance with the provisions of 10 CFR 2.790 of the Comission's regulations and in conjunction with the application of Omaha Public Power District, for withholding this information.

The information for which proprietary treatment is sought is contained in the following document:

CEN-150(0) - P, Analysis of CECOR Power Peaking Uncertainties For Ft.

Calhoun Unit 1 Cycle 6, February, 1981.

This document has been appropriately designated as proprietary.

I have personal knowledge of the criteria and orocedures utilized by Combustion Engineering in designating infomation as a trade secret, privileged or as confidential commercial or financial information.

Pursuant to the provisions of paragraph (b) (4) of Section 2.790 of the Comission's regulations, the following is furnished for consideration l

by the Commission in determining whether the information sought to be withheld from public disclosure, included in the above referenced document, I should be withheld.

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1. The information sought to be withheld from public disclosure are the methodology related to the determination of power distribution measurement uncertainties and the statistical models used to determine the uncertainty estimate, which is owned and has been held in confidence by Combustion Engiaeering.

2. The information consists of test data or other similar data concerning a process,' method or component, the application of which results 4

in a substantial competitive advantage to Combustion Engineering.

3. The information is of a type customarily held in confidence by Combustion Engineering and not customarily disclosed to the oublic.

Combustion Engf aeering has a rational basis for determining the types of information customarily held in confidence by it and, in that connection, utilizes a system to determine when and whether to hold certain types of infomation in confidence. The details of the aforementioned system were provided to the Nuclear Regulatory Commission via letter DP-537 from F.M. Stern to Frank Schroeder dated December 2, 1974. This system was applied in detemining that the subject documents herain are proprietary.

4. The information is being transmitted to the Commission in confidence under the provisions of 10 CFR 2.790 with the understanding that it is to be received in confidence by the Commission.

5. The information, to the best of my knowledge and belief, is not available in public sources, and any disclosure to third parties has been made pursuant to regulatory provisions or proprietary agreements which provide for maintenance of the information in confidence. l l

l l

1

6. Public disclosure of the information is likely to cause substantial harm to the comoetitive position of Combustion Engineering because:

a. A similar product is manufactured and sold by major pressurized water reactors competitors of Combustion Engineering.

b. Development of this information by C-E required tens of thousands of manhours of effort and hundreds of thousands of dollars. To the best of my knowledge and belief a competitor would have to undergo similar expense in generating ~ equivalent information.

c. In order to acquire such information, a competitor would also require considerable time and inconvenience related to the development of methods and statistical models for determining power distribution measurement uncertainties,

d. The information required significant effort and expense .s obtain the licensing approvals necessary for application of the information.

Avoidance of this expense would decrease a competitor's cost in applying the information and marketing the product to which the information is applicable,

e. The information consists of methods and statistical models for the determination of power distribution measurement uncertainties, the application of which provides a competitive economic advantage. The availability of such information to competitors would enable them to modify their product -

i to better compete with Combustion Engineering, take marketing or other actions to improve their product's position or impair the cosition of Combustion Engineering's product, and avoid developing similar data and analyses in support of their processes. methods or apparatus.

f. In pricing Combustion Engineering's products and services, significant research, development, engineering, analytical, m:nufacturing, licensing, quality assurance and other costs and expenses must be included.

~

I The ability of Combustion Engineering's competitors to utilize such information without similar expenditure of resources may enable them to sell at prices reflecting significantly lower costs.

g. Use~ of the information by competitors in the international marketplace would increase their ability to market nuclear steam supply systems by reducing the costs associated with their technology development.

In acdition, disclosure would have an adverse economic impact on Combustion Engineering's potential for c'ataining or maintaining foreign licensees.

Further the deponent sayeth not.

f. / ns <

' } k f, (//- (, yj P. L. McGill Vice President Comercial Sworn to before me thisJC day of fiI LLu/: C /If I

/

' . :w, l I L. ~. : j Notary Public y -

CAREY J. 'T2F6.L, NOTA 2Y PUBLIC Sta:s :l Ca.1.ca:Sc;tf4.59962 Commission Exp)tes Mart.a 31,1985 l

l

C0t@USTION ENGINEERItC, INC.

Report CEN-150(0)-NP Analysis of CECOR Power Peaking Uncertainties For Ft. Calhoun Unit 1 Cycle 6 February 1981 l

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.0 LEGAL l'0TICE This report was prepared as an account of work sponsored by Combustion Engineering, Inc. Neither Corabustien Engineering nor any persen acting cn its. behalf:

A. Makes any warranty or representation, expressed or icplied including the warranties of fitness for a particular purpose or merchantability, with respect to the accuracy, completeness, or usefulness of the informatien contained in this report, or that the use of any informat-ion, apparatus, method, or process disclosed in this report may not infringe privately owned rights; or

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B. Assumes any liabilities with respect to the use of, or for damages resulting frem the use of, any information, apparatus, method or process disclosed in this report.

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. ,* 1 1.0 Introduction This report presents the results of an analysis of the CECOR po er peaking uncertainties for Ft. Calhoun Unit 1 Cycle 6. The analysis was performed to assist The Omaha Public Power District (OPPD) in establishing a program

- for compliance with requirements of the Interim Special Technical Specifications (Reference 1) approved in February 1981. The revised

- technical specifications allow for an increased number of failed in-core detector strings (up to 80% of the total) and at the same time impose a periodic requirement to evaluate of the CECCR uncertainties. .

The analysis of the CECOR power peaking uncertainties is based on calculational and operating data for Ft. Calhoun Unit 1 Cycle 6 available up to . December 1980. At that time 5 of 28 (or 18% of total) detector strings had failed.* In view of the history of detector failures for Cycle 6, the analysis considered both the observed failures and extrapolated future failures to determine the expected effect on the CECOR uncertainties.

The analysis was performed in three parts: The first part evaluated the basic measurement uncertainties for F, F and F based on r q xy core-follow calculations for Cycle 6. The second part evaluated the box synthesis uncertainties for the configuration with all observed failed

.ietectors, and for configurations with extrapolated f ailed detectors. The final part of the analysis evaluated the overall CECOR uncertainties using results of the first two parts and the methodology in Refererce 2. The overall uncertainties were ccmpared against the present Cycle i Technical

, Specification values of 6% for Fr '

7% for Fq, F xy

+ A detector string is defined as failed if two detectors in the axial string have failed signals.

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In additicn, the expected effect of extrapolated detector failures on the overall- uncertainty was evaluated. Recommendations for conservative

, compliance with the Interim Special Technical ,

Specificatiens were developed based on the results of the analysis.

. 1.1 Summary of Results

- A detailed description of the analysis is given in Chapter 2. The major results are as follow:

i) The calculation of the overall CECOR uncertainties based on observed f ailed detectors and operating data thrcugh 3000 MWD /T cycle burnup indicates ccmpliance with the Technical Specification =. The calculated uncertainties are for Fr

for F ,

q for F xy.

ii) The basic measurement uncertainty values show a decreasing trend after 1000 MWD /T cycle burnup. This may be attributable to the more likely failure of instruments (e.g., the most aged instruments) which have greater than average errors in calculated sensitivity. This trend is expected to continue through Cycle 6.

iii) The box synthesis uncertainties were found to increase by less than

( above reference calculation values for uncertainties sub2tantial extrapolatec detectcr failures. The ccabined CECOR

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showeo an increase of or less for the extrapolated failure analysis.

2

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e -9 1.2 Recocmendaticns Based on the results of the analysis, the following recommendations are made for complying witn the Interi : Special Technical Specifications:

i) Increase the CECCR uncertainties used for ' Cycle 6 to 1% above the values in the - Tcchnical Specifications. This will: conservatively allow for increased synthesis errors due to future detector failures. The recommended CECOR uncertainty values are 7% for Fr, 8% for F , F q xy.

ii) Calculate the basic measurement uncertainties at the periodic intervals required. If the measurement uncertainties do. not exceed the values in the reference calculation (Section 2.1), it is then conservative to concluce that the overall CECOR uncertainties are.

within the reccmmended values above, provided that expected normal core - operation is maintained. This procedure replaces the need to periodically calculate the synthesis and combined uncertainties. In the event that either the measurement uncertainties exceed- the reference calculation values, the core power distribution departs I

significantly frem nominal, or detector f ailures approach the limits in the Interim Special Technical Specifications, then the synthesis and combined uncertainty calculations should be performed.

- 2.0 Analysis The loading and instrument pattern for Ft. Calhoun Unit 1 Cycle 6 is shown in Figure 1 and the history of failed instruments through December 1980 is given in Table I. These data show the detector failures to be )

concentrated among the most aged instruments (MOC2/BOC3 batches) and in (

the BOC5 batch. Additionally, it is seen that over half (15 of 28) of the j in-core locations for Cycle 6 have MCC2/B0C3 batch detectors, while six locations have 80C5 batch detectors. In this analysis, extrapolated future failures through Cycle 6 were considered to be within these instrument batches.

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2.1 Basic Measurement Uncertainty The basic measurement uncertainty values were obtained from ins'trument box power Ecortparisons of ROCS and CECOR calculations, "following the method described in Part I of Reference 2. The ROCS and CECOR calculations used represent the Cycle 6 core operation from 300 to 3000 MWD /T, as indicated in Table II. The 2000 MWD /T time potat includes all detector f ailures

. through October.1980.

The ROCS-CECOR ccmparison results over instrumented locations for the five time points are summarized in Table III. These results show that the greatest measurement uncertainty values occur at the 1000 MWD /T time point, while the values decrease for both the 2000 and 3000 MWD /T time points. _

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The measurement uncertainty values are given in ~able IV.

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The values for each parameter include the estimated standard deviation (S), number of degrees of freedom, the 95/95 probability / confidence factor (k95/95) and upper tolerance limit (kS). The standard deviation values are given in units of percent of peak assembly value. (

) The_

values l

were used in the calculation of combined CECOR uncertainties described in Section 2.3. The k 95/95 f actors shown in Table IV were obtained using Reference 4.

1 Additional ROCS-;.ECOR instrument location ccmparisons were performed for extrapolated detector failures in the MOC2/ SOC 3 end BCC5 batches. The results showed lower uncertainty values than the reference calculation

above, consistent 'with the expectation that the basic measurement uncertainty may inprove slightly by elimination of instruments with greater than average ~ errors in calculated sensitivity. The actual i I

core-follow calculaticns for Cycle 6 show a decreasi-ng trend in the basic measurement uncertainty with burnup, as indicated in Table III.

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2.2 Box Pcwer Synthesis Uncertainty The ' box power synthesis analysis was performed using a reference design ROCS depletion 'calculatica and CECOR synthesis calculations representing various failed detector configurations. The methodology used for the synthesis analysis'is described in Part II of Reference 2.

The ROCS reference calculation was a three-dimensional, quarter-core, nominal depletion calculation to 10,000 MWD /T based on the core configuration shcwnin Figure 1. A full core CECCR synthesis model was _

constructed which utilized the ROCS calculation depletion structure .

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The first CECOR synthesis calculation

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treated all detectors listed in Table I as failed thrcughout the depletion. This case is the source of the basic synthesis uncertainty values used in the ccmbineo uncertainty analysis in Section 2.3.

l Additional synthesis calculations were performed for extrapolated detector failures in the M0C2/BOC3 and BCC5 batches.

The synthesis uncertainty estimate; for F, F and F,, were obtained

. r q by comparing the CECOR synthesis and ROCS reference calculation box power distributions at each depletion time point in accordance with the procedures in Reference 2. The ROCS-CECOR comparison results for the

-basic synthesis case using all observed failed detectors are summarized in Table V. The worst-case time point value _

is indicated for each parameter.

The synthesis uncertainty values for Cycle f, derived from these data are

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given in Table VI. _

The values of standard deviation (S), bias (D) and the number of degrees of freedom given in Table VI were used in the ccmbined uncertainty analysis in Section 2.3. The S and D values are quoted in units of percent of peak box value. _

The probability / confidence factor values were (k95/95) obtained using Reference 4.

Additional synthesis comparisons were made for cases extrapolating extensive f ailures among the MOC2/ SOC 3 and 80C5 instrument batches. The ROCS-CECOR ccmparisen results for these cases showed small, progressive synthesis errors due to additional f ailed detectors. The case with the maximum extrapolated failures treated all M0C2/BCC3 and 80C5 batch instruments, or 3/4 of all detectors, as failed. The results of the ROCS-CECOR ccmpariscns for this case are summarized in Table VII.

. Comparison of these results against the results for the case of observed failures in Table V show that the maximum synthesis errors attribuiable to

.mo be

the' extrapolated detector failures are about ,,

for . F ,

q . -

for F r

and for F .

These errors are considered small in magnitude, and

. - xy may be indicative of more separable radial and axial power distributions for Ft. Calhoun Unit 1 Cycle 6 than for the larger later cycle cores used for-the data base in Reference 2.

2.3 Combined Uncertainty.

basic The combined uncertainty analysis was performed using the measurement and synthesis uncertainty results described in Sections 2.1 and 2.2, and the procedure given in Part III of Reference 2. 'The pin peak calculative and synthesis uncertainty components from Reference 2, which are-not affected by detector failures, were included in the combined uncertainty calculations.

The values of the ccif.penents used for the ccmbined uncertainty calculation representing the operation of Ft. Calhoun Unit 1 Cycle 6 up to December 1980 are given in Table VIII. The overall CECOR uncertainties are given by the 95/95 probability /cenfidence upper one-sided tolerance limit (0+kS) for each parameter. The values,

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for F' r

for F, q

for F xy, are within the Technical Specification values of 6% for F r and 7% for Fq and F xy.

The combined uncertainties were also analyzed for cases with extrapolated failed detectors. These evaluations assumed no change in the basic measurement uncertainties, based on the analysis described in Section 2.1, and incorporated synthesis calculation results for extrapolated detector failures. The results of this analysis projected ,a maximum increase in the overall uncertainty value of for F ,

q . .

for F, and for Fx , fcr extrap0 lated failures in the .M0C2/30C3 and r , ,

80C5 instrun.ent batches. Based on this analysis it is judged conservative to allow for increased synthesis errors in the event of future detector

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failures in Cycle 6 by adding a 1% penalty to the existing uncertainty values for Fr

• Iqand F .

2.4 Compliance .

Based 'on the analysis in this report it-is recommended that the following procedures be . adopted by CPPD for compliance with the Interim Special

. Technical Specifications (ISTS): First, as a conservative measure to allow for expected. future in-core detector failures, the overall CECOR uncertainties should be increased uniformly . by 1% above t5e ISTS values.

Thus it is recommended that the uncertainty values utilized in the ISTS be assigned values of 7% for U, p

8% for U,U xy.

o q The basic measurement uncertainties should be evaluated periodically (every 31 EFPD of aperation) using the procedure in Section 2.1. _

If the standard deviation ve' .es obtained do not exceed tne rererence ~

values in Table III, then it can be reported , en th2 basis "of the analysis in Sections 2.2 and 2.3, that the overall unce-tainties are less then the above recommended values, in compliance with the ISTS requirement. This measure eliminates the need to periodically reevaluate the' synthesis uncertainties for future expected normal core cperation of Cycle 6. If the basic measurement uncertainty values obtained exceed the reference values in Table III, then it wculd be necessary to perform the synthesis and combined uncertainty calculations as in Sections 2.2 and 2.3 to comply with the ISTS.

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3.0 References-

1. " Application For Amendccnt of Operating License," U.S. i:RC Docket tto.

50-285, Omaha Public Power District, January 1981.

" Safety Evaluation by the Office of fluclear Reactor Regulation Supporting Amendment tio. 55 to Facility Operating License ?!o. OPR-40, Omaha Public' Pcwer District, Fort Calhoun Station, Unit flo.1, Docket

- No. 50-285," . S. NRC, February 2, 1981.

2. A. Jonssen, W. B. Terney and M. W. Crump, " Evaluation of Uncertainty in the Nuclear Powr.r Peaking Measured by the Self-Powered Fixed Lin-core Detecter System," CENPD-153-P, Rev. 1-P-A, May 1980.

3. W. J. Dixon, 4F. J. Massey, Jr., " Introduction to Statistical Analysis," McGraw Hill Book Co., 1969.

4. " Factors for One-Sided Tolerance Limits and for Variables Sampling Plans, "

Sandia Corporatic n Monograph, SCR-607, 1963.

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TABLE I I!:C3RE DETECTCR FAILURES Occember, 1980 -

Date Failed Instr.# -Level Batch #

BOC6 3-4 Cycle 5 (80CS)

BOC6 10-1 Cycle 3 (80C3)

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BOC6 14-4 Cycle 3 (80C3)

BOC6 20-3 Cycle 3 (SOC 3) 6/16/80 21-4 Cycle 5 (SOCS) 7/11/80 17-4 Cycle 5 (80C5) 7/15/80 25-3 Cycle 3 (80C3) 7/16/80

^

. 18-1 Cycle 3 (80C3) 8/20/80 21-3 Cycle 5 (80C5) 8/22/80 3-3 Cycle 5 GCCS) 8/25/80 ' 12-4 Cycle 5 (EOCS) 9/1/80 26 erratic Cycle 2 (POC2) 9/8/80 23-3 Cycle 5 (80CS) 9/8/80 7 erratic Cycle 3 (BOC3) 9/23/80 4-4 Cycle 2 (MOC2) 10/6/80 18-2 Cycle 3 (SOC 3) 11/11/80 20-2 Cycle 3 (80C3)

. 12/3/80 17-3 Cycle 5 (SOC 5)

T

• • M - * ' " " " * -

OW e P+-e 44 -9 *4e- **#4 I O h mgg 6 g6y M S&JG O h9 Mf*

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4 TABLE II Fort Calhoun Unit 1 Cycle 6 Comparison Snapshot Operating Data Faile,d Detectors ,

Power Rod

• Level 4 Burnup Level Insertion Level 1 Level 2 Level 3 10 none 20 3, 14, 21 b:.300 99% 0%

8 10 none 20 3, M. M 500 100% 0%

10, 18 none 20, 25 3, 14, 17, 21 1000 100% 0%

10, 18 .none 3, 20, 21, 25 3, 12, 14, 17, 21

.2000 99% 0%

7, 10, 18 18 3,-20, 21, 23, 25, 26 3, 4, 12, 14, 17, 21 3000 66% 0%

1

• All rods out 4

1

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TABLE III Ft. Calhoun Unit 1 Cycle 6 Sumary of Measurement Uncertainty for All Timepoints SFXY Level 1 Level 2 N(2)-1 Level 3 N(3)-1 Level 4 N(4) Burnup 'N(1)-1

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- ~

~

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27 26 24 300 MHD/T 26 27 26 24 500 MWD /T 26 27 25 23 1000 MWD /T 25 27 23 22

.' 2000 MWD /T 25 .

26 21 21 Y 3000 MWD /T 24 _ _

. SFXY

~

NDEG SFR NDEG Burnup _

HDEG SFQ

- ~

~ ~

~

103 103 22 300 MWD /T 103 103 22 500 MWD /T 100 100 19 1000 MWD /T 97 97 18 ,

j 2000 MUD /T 92 92 14 3000 MWD /T .

_ , - = .

495 95

_j [ 495 ., _

6

4

-. ..,i ...

3 TABLE IV

• Summary of Uncertainties For the Measurement of Peak Assembly Pcwer k .kS Number of Degrees of Freedom 95/95 Quantity S F

r F

xy F

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• Quoted in percent of peak assembly value 4

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TABLE V Ft. Calhoun Unit 1 Cycle 6 Synthesis - Observed Failed Instruments Bias and Standard Deviation of Difference Between ROCS and CECOR Calculations F F F q r m Burnup r

(MWD /T) D S N 6 S N 6 S N _,

133 133 11 500 1000 133 133 11 2000 133 133 11 3000 133 133 11

~

4000 133 133 11 5000 133 133 11 6000 133 133 11

^

7000 133 133 11 8000 133 133 11 9000 133 133 11 10000 133 133 11 4

I

+ Worst-case Value l 1

i

..7.

TABLE VI

. Summary of Synthesis Uncertainties Number of Degrees

- Box Power + 6 S of Freedom k95/95 6 + kS

, F r

F xy F

9 _.

~

• Quoted in percent of peak box value.

1 4

4 I

e a

,, , . , y- - . . - - - - - ., , , , , - , , , , , . , , . - , , , , , . . . - - , , , , - - - , - - , -

.. 4 ..

TABLE VII

- Ft. Calhoun Unit 1 Cycle 6 Synthesis -Extrapolated Failed Instruments Bias and Standard Deviation of Difference Between ROCS and CECOR Calculations F F F

q r xy Burnup

. (MWD /T) 6 S N 6 S N D S N 133 11

-500 133 133 133 11 1000 133 133 11 2000 133 11 3000 133 133 133 < 11 4000 133 133 11 5000 133 133 11 6000 133 133 11 7000 133 133 11 8000 133 133 11 9000 133 133 11 10000 _ _ _ _

9

+ Worst-case Value

TABLE VIII -

Ft. Calhoun Unit 1 Cycle 6 Summary of Uncertainty Components Parameter li S f k95/95 li+ks

(%) (%) (%)

F Box Meas.

q Synth.

Pin Calc.

Synth . . . . _ . . ..

~ ~ ~ - ~ ~ ' ~ ~

Combined - l

_ _ _ J _ _ _ _ _ .

F Box Meas.

r 1 . Synth.

Pin Calc.

Synth. . _ _ _ _ _ ._

Combined l _ -- . _ _ . . . .

F Box Meas.

xy Synth.

Pin Calc.

Synth. _ _ _ _ ,__, . _ _

Combined

\

l 4

l

' Figure 1 .

LOADING a INSTRU.'.1ENT PATTERN FORT CALHOUN UNIT 1 CYCLE G BOX No.

CH --

_ ] NINSTR.No.

I H 1 H 2 H 3 H 4 INSTR.

BATCH

' H 5 H 6 H 7 F/ 8 G 9 FI 10 H 11 H 12 H 13 H 14 G 15 E 16 F/ 17 ' G 18 F 10 G 20 F/ 21 E 22 G 23 H 24 2 1 BOC3 BOC3 H 25 E 26 G 27 G 23 F 29 C 30 F 31 G 32 G 33 E 34 H 35 6 5 4 3 BOCS f.tO C2 f.iOC2 BOCS H 36 F/ 37 G 38 F 39 G 40 F 41 G 42 l F 43 G 44 F/ 45 H 46 H 47 ., H 43 10 BOC3 F/ 49 G 50 F 51 G 52 E 53 G 54 E 55 G SG F 57 G 58 F/ 59 BOC6 f.*0 C2 BOC3 G 62 F G3 ' G 64 F 65 G G6 0 67 G 63 F 63 G 70 F 71 G 72 17 BCC4 16 15 14 13 12 H 73 BOC5 BOC6 H 74 BOC3 BOC3 BOC6 BOCS F/ 75 G 7G F 77 G 73 E 79 1 G SC E C1 G 82 F 83 G 84 F/ 85 20 19 1B H as BOC3 H 87 f.10C2 BOC3 H 83 F/ 89 G 90 F 91 G 92 F 93 G 94 F 95'G 96 F/ 97 H 98 22 21 BOC6 BOC5 H 99 E 100 G 101 G 102 F 103 G 1C4 F 105 G 106 G 107 E 1C3 H 109 26 25 24 23 MOC2 BOC3 BOC5 BOC5 H 110 G 111 E 112 F/ 113 G 114 F 115 G 116 F/ 117 E 118 G 119 H 120 23 27 BOC4 BOC3 H 121 H 122 H 123 F/ 124 G 125 F/ 12S H 127 H 123 H 129 H 130 H 131 H 132 H 133

. l i

I 1

4 P00RORISNAl.