ML19347C989
| ML19347C989 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 03/04/1981 |
| From: | Lundvall A BALTIMORE GAS & ELECTRIC CO. |
| To: | Clark R Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19260G691 | List: |
| References | |
| NUDOCS 8103100445 | |
| Download: ML19347C989 (24) | |
Text
4 B ALTIMORE G AS AND ELECTRIC COMP ANY P O. B O X 1475 B A L T I M O F< E M A R Y L A N D 21203 NUCLE AR POWER DEPARTMENT COLVERT CLIFF 5 NUCLE A R POWER PLANT March 4, 1981 tussy,uaRyta~o 23 s2
,, /^!y F1 19 g
O fl)y Ng%g j
-f' V g Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission g
Washington, D. C. 20555 4
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q 3
f ATTENTION:
Mr. R. A. Clark, Chief Operating Reactors Branch #3 gh.
ff 6
Division of Licensing h[h(
.c 4'
D SUEJECT:
Calvert Cliffs Nuclear Power Plant Unit No. 1, Docket No. 50-317 Responses to NRC Questions on BASSS (CEN-119(B)-P1 REFERENCE (A):
R. A. Clark to A. E. Lundvall letter, dated December 30, 1980 Gentlemen:
Referenca (A) presented several NRC staff questions on Combustion Engineering, Inc.'s topical report, Better Axial Shape Selection (BASSS).
Enclosures (1) and (2) are Combustion Engincering's responses to those questions.
Enclosure (3) is an affidas't frem Combustion Engineering, Inc., requesting that information in E.losure (1) be withheld from public disclosure in accordance with 10 CFR 2.790.
Very truly yours,
[
BALTIM0?C GAS 1ND
_CT IC COMPANY A
mW f
A. E. Lun all, Jr.
Vice President - Supply AEL:WJL:mit Yt 8103100
Office of Nuclear Reactor Regulation March 4, 1981 Page 2
Enclosures:
(1) Responses to First Round Questions from NRC on the BASSS Report (CEN-119(B)-P), February 1981 (Proprietary)
Copies 1-25.
(2) Responses to First Round Questions from NRC on the BASSS Report (CEN-119(B)-NP), February 1981 (Non-Proprietary) 20 copies.
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(3) Proprietary Affidavit.
l Copy To:
J. A. Biddison, Esquire (w/out Encl)
G. F. Trowbridge, Esquire (w/out Encl) l E. L. Conner, Jr., NRC l
P. W. Kruse, CE (w/out Encl.)
i l
l l
l 1
ENCLOSURE (3)
AFFIDAVIT PURSUANT T0 10 CFR 2.790 Combustion Engineering, Inc.
)
State of Connecticut
)
County of Hartford
)
SS.:
I, A. E. Scherer depose and say that I am the Director, Nuclear Licensing, of Combustion Engineering, Inc., duly authorized to make this affidavit, and have reviewed or caused to have reviewed the information which is identified as proprietary and referenced in the paragraph immediately below.
'I am submitting this affidavit in conformance with the provisions of 10 CFR 2.790 of the Commission's regulations and in conjunction with the application of Baltimore Gas and Electric Company, for withholding this information.
The information for which proprietary treatment is sought is contained in the following document:
Responses to First Round Questions from the NRC on the Better Axial Shape Selection System (BASSS) Report CEN-119(B)-P.
l This document has been appropriately designated as proprietary.
I have personal knowledge of the criteria and procedures utilized by Combustion Engineering in designating information 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 Commission's regulations, the following is furnished for consideration by the Commission in determining whether the information sought to be withheld from public disclosure, included in the above referenced document, sh6uld be withheld.
1.
The information sought to be withheld from public disclosure are the theoretical basis, the equations and the numerical values utilized in developing BA555, which is owned and has been held in confidence by Combustion Engineering.
~
2.
The information consists of test data or other similer data concerning a process, method or component, the application of which results 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 tne public.
Combustion Engineering has a rational basis for determining the types of information customerily held in confidence by it and, in that connection, utilizes a system to determine when and whether to hold certcin types of information in confidence.
The details of the aforementioned systen were provided to the Nuclear Regulatory Comission via letter DP-537 from F.M. Stern to Frank Schroeder dated December 2, 1974.
This system was applied in determining that the subject documents herein 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 conf!dence 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.
6.
Public disclosure of the information is likely to cause substantial harm to the competitive position of Combustion Engineering because:
a.
A similar product is manufactured and sold by major pressurized water reactors competitors of Combustion Engineering.
3-b.
Development of this information by C-E required hundreds of manhours and tens of thousands of dollars.
To the best of my knowledge and belief a competitor would have to undergo similar expense in generating
[
equivalent information.
i c.
In order to acquire such information, a competitor would also require considerable time and inconvenience related to development of f
the theoretical basis and the methodology for BASSS.
[
d.
The information required significant effort and expense to obtain the licensing approvals necessary for application of the information.
[
Avoidance of this expense would decrease a competitor's ccst in applying the information and marketing the product to which the information is applicable.
(
e.
The information consists of the theoretical basis, the
[
equations and the numerical values utilized in d / eloping BASSS, the application of which provides a competitive economic advantage.
The availability of such information to competitors would enable them to modify their product to better compete with Combustion Engineering, take marketing or other actions to improve their product's position or impair the position of Combustion Engineeriig'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, manufacturing, licensing, quality assurance and other costs and expenses must be included.
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.
4
(
4-l l
g.
Use of the ir armation by competitors in the international marketplace would increase their aeility to market nuclear steam supply systems by reducing the costs associated with their technology development.
In addition, disclosure would have an adverse economic impact on Combustion Engineering's potential for obtaining or maintaining foreign licensees.
Further the deponent sayeth not.
/
/
e-A. E 4ch'Grer f
Director Nuclear Licensing Sworn to before me l
this 20th day of February 1981 LtieLu )
(U: n 9 :-)
Notary PublJc s
l CGFX ? ?7E'.!EL, NOT.iEY PUELIO h.c c' Con;4:!ct No. 53362 Comm!nca E::;.:res March 31. 1955 l
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_. - _ _ _. _. _.. _ _ _ _ _ _.. _,, _ _ _.. _ -. _.....,. _ - _. _ _ _ _ _ _ _..... _ _ _ _.. _ _. _. ~. _. _ _.. _ _.
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Responses to First Round Questions from the NRC on the Better Axial Shape Selection System (BASSS) Report CEN-119(B)-NP t
February 1981 l
Combustion Engineering, Inc.
I l
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b
,i LEGAL NOTICE This report was prepared as an account of work sponsored by Combustion Engineering, Inc. Neither Combustion Engineering nor any person acting on its behalf:
A.
Makes any warranty or representation, express or
\\
implied including the warranties of fitness for a particular purpose or merchantability, with respect to the accuracy, completeness, or usefullness of the information contained in this report, or that the use of any information, apparatus, method, or process disclosed in this report may not infringe
- privately owned rights; or B.
Assuaes any liabilities with respect to the use of, or for damages resulting from the use of, any information, apparatus, method or process disclosed in this report.
s l
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D.
i TABLE OF CONTENTS 2
i Page i
1.
Response to Question #1 I
1 Part a 3
Part b 4
Part c 5
Part d 6
2.
Response to Question #2
)
3.
Response to Question #3 7
Part a 8
Part b 9
l Part c l
r i -
4 e
Question 1.a How ware the empirical relationships derived for the equations and correlations on page 7?
Response
The axial shape index equation (1)
!ASI =
was derived from the standard axial shape index (ASI) equation L-U IASI = I
=
TW (2) where L is the power in the lower half of the core and U is the power in the upper 4
half of the core. The first term on the right hand side of equation (1) was developed by applying the method used in INCA (Reference 1) for synthesizing axial powers for instrumented assemblies in order to calculate a core-average i
axial power distribution. This fomulation consists of fitting three Fourier functions to the equivalent power for adjacent levels of incore detectors to synthesize the power distribution in each half of the core. Hence the power in the upper and lower halves of the core is given by af
+ bf
+ cf and U
=
j 2
3 f
+ b*f
+ c*f (3)
L = a*j )
2 3
where f, f and f are three simple Fourier modes and (a,b,c) and (a*,b*, c*)
j 2
3 are fitting constants. The fitting constants are detemined from the level-averaged powers of any three adjacent detector levels (See Figure 1). Using this methodology, equation (2) can be written as:
(4)
IASI
=
By collecting like terms containing the level averaged p'owers, equation (4) can be written in the same fom as the first term on the right hand side of equation (1).
The second term on the right hand side of equation (1) accounts for the difference between the calculation of ASI using the synthesized representation for L and U and calculation of ASI using actual values of L and U.
This term [
]
since only 45 of the 217 assemblies in the core are instrumented and the axial shape'index [
].
1
t PSINCA calculates BLIM in the following manner:
(5)
BLIM
=
The coefficients in this equation are described in Table 1.
This algorithm calculates the allowable power level (BLIM) and is [
] with coefficients that are [
~
].
I The ASI region of interest for the DNB LCO is divided into [
]
(see Figure 2).
The [
] of the BLIM equation [
]. A set of coefficients is calculated for [
].
The [
] adjust the values of the [-
] to account for [
] The same coefficients are applied to [
].
Coefficients [
] are defined by [
).
The'[
] to the DNB LC0 limit curves is obtained for the range of CEA insertions monitored by BASSS, [
] (see Figure 3). To account for the possibility that measured radial peaks are higher than [
] a factor [ ] is incorporated in the BLIM equation.
This factor [
] the technical specification limit.
l l
2
t Question 1.b Also, with what confidence are they applicable to what range?
Response
The IASI ranges discussed in page 7 of the BASSS report (see Table 1) are the range of [
], There is no specific probability or confidence level associated to these ranges except that the input is biased to be conservative and the [
]
are inherently conservative as described above.
T I
i
- f -
~
s d
3
Question 1.c Specifically, are C1, C2, C3 and C4 channel dependent?
i
Response
The constants C1, C2, C3 and C4 are not channel dependent since the derivation of equation (1) involved the core-average axial power distribution.
- These constants are derived from the three Fourier fitting functions and are burnup dependent.
9 l'
e D
4 L
,.-t Question 1.d How is [
] calculated?
i
Response
The [
] term is calculated by comparing the ASI determined from a [
] and the ASI determined by PSINCA using [
]forselectedoperatingstates of the reactor.
[
] is cycle-dependent.
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j.
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l..
~
... z..
.2.
I Question 2 The octant representation of incore detectors in the entire core as given in Figure 2, page 19, shows where the redundant readings are obtained using the assumption of eighth core symmetry.
The spread of detector signals within a given eighth core symmetric location is not accounted for in any analysis in this document. Justify why the spread in signal for all properly functioning incore detectors should not be used as a measure of octant asymetry and therefore treated as a penalty (or reduced margin) when determining the core operating limits.
Response
The spread in detector signals is included in the analysis in two ways.
First a total ASI uncertainty [
] was used in the calculation of the coefficients in equation (5) to account for several uncertainties involved in the calculation of I [
], Through a comprehensive uncertainty analysis (Reference 2),
a 95/95 confidence / probability value of the ASI uncertainty was combined with
~
uncertainties on other parameters involved in the calculation of BLIM to determine the total uncertainty on BLIM.
The second way that the spread of detector signals is included in the in the determination of allowable power level.
analysis is through the use of FR F
is defined on Page 13 of the BASSS report.
It includes the azimuthal tilt R
parameter. The azimuthal tilt is a measure of core asymetry. Technical Specification 3.2.3 allows an azimuthal tilt of no more than 3% at full power.
By including this factor, [
]toBLIMtoaccount for possible core power asymmetries.
t 6
L
Question 3.a When a nonredundant incore detector signal is missing, the signal is synthesized by using the nonredundant detector coupling pattern as given by Figure 3 on page 20 with appropriete coupling coefficients. How is this coupling calculated?
Response
The coupling coefficients are determined by calculating the ratio of the power in a nonredundant quarter-core location with the power in the coupled redundant location [
]. These ratios are calculated [
]. A [
] is made to this data to determine the coefficients used in PSINCA. This method of generating coupling coefficients is similar to that used in INCA (Reference 1).
l t
l
[
t Ouestion 3.b Also, since this signal has in effect been synthesized, one signal is in effect being used twice. Therefore, should not there be some penalty as a function of the number of synthesized signals?
j
Response
The effect of tt< presence of[
] detectors was taken into account in the ASI uncertainty analysis described in Reference 2.
It has 3
been included in the overall uncertainty and subsequently included in the l
calculation of allowable power level as explained in response #2.
L
(
8
Question 3.c Also, what is the maximum allowed number of missing signals?
Response
Technical Specification 3.3.3.2 allows a r:ximum of 25% failed detector 1
strings. A failure level of[
]was assumed in the development of the total uncertainty on ASI. This failure level [
]with respect to Technical Specification 3.3.3.2.
1 e
4 t
o r
l 9
Figure 1 Definition of Quantities Used in Equations (1) and (2) i i
i Synthesized Core Incore Instruments Average Power
^
r P1 u
k P2 I
s CDE MIDPLNE
~
~
i P3
{
\\g 1
h
?
COE l
I I
10 1
.9-,
w
-,-s-
-g e
Figure 2
^
Typical DNB LCO Calculated by PSINCA.
110 l
y e
ALL RODS OUT'
~
~
100
- 6 d
BLIM
//
BANK 5 BANK 5
(% POWER) 15% INSERTED
$5% INSERTED /
j l
i.-
' ' ' Il '
90 i
-0.30
-0.20
-0.10 0.0 0.10 0.20 0.30 n.40 IASI (ASIU)
Figure 3 Typical Fit of BASSS Algorithm to Actual Limit f
N 9
O e
9 4
e i
e e
N 12
r e
e
_TA41.F. 1 ALI.ONABLE POWER LEVEL CALCULATION
.The a gor t n used by PSitCA to calculate the allowabic power Icvel l
ih (BLIt0 uses the core averar,e axial shape index, the amount of insertion of the first. regulating bank, and the associated total integrated radial peaking factor.
PSI!1CA calculates BLIM in the following manner:
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i f
13 i
_ ~.__.
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)
4 REFERENCES i
- 1. " INCA /CECOR Power Peaking Uncertainty". CENPD-153-P, Revision 1-P-A, May 1980.
- 2. " Statistical Combination of Uncertainties, Part 3"CEN-124(B)-P, March 1980.
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