ML20002A270
| ML20002A270 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 11/03/1980 |
| From: | Lundvall A BALTIMORE GAS & ELECTRIC CO. |
| To: | Clark R Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19260G385 | List: |
| References | |
| NUDOCS 8011050488 | |
| Download: ML20002A270 (21) | |
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'B AL.TIMOR'E G AS AND ELECTRIC COMPANY P.O. B O X ' 14 7 5
~ B A LTIM O R E. M A R Y L A N D 21203 i
DaTHun E. tA oval.,Jn..
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November 3, 1980 e
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. Office of Nuclear Reactor Regulation Oh; b
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U. S. Nuclear Regulatory Commission l6:,~is v.; -
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- Washington, D. C. 20535 Qa6 3
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ATTENTION:
Mr. R. A. Clark,' Chief M
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Operating Reactors Branch #3 C
y Division of Licensing
SUBJECT:
Calvert Cliffs Nuclear Power.'lant 4
Unit No.1, Docket No. 50-317 Amendment to Operating License DPR-53
~
Fif th Cycle License Application -
{
Responses to NRC Staff Questions Gentlemen:
3
' Enclosed are our reponses to questions posed by NRC staff on the subject' application.
l Very truly yours, l;
' BALTIMORE GA,5 A D TRIC COMPANY
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(y(A. E. Lun vall, Jr.
Vice President - Supply f
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Copy To:
- 3. A. Biddison, Esquire (w/out Encl.)
l G. F. Trowbridge, Est;uire (w/out Encl.1 Messrs.
E. L. Conner, Jr., NRC
- P. W. Kruse, CE
= Enclosure (Calvert Cliffs Unit 1, Cycle 5 NRC Reload Questions Response - Answers on Asymmetric ' Steam Generator Protective Type Function, 10/31/80)-
Proprietary Copies #00001 -' 000040; 20 Non-proprietary copies 4
3
,801'1050' g%
AFFIDAVIT PURSUANT TO 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 Commiss'on'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:
Calvert Cliffs Unit 1, Cycle 5, NRC Reload Question Responses (Answers on Asymmetric Steam Generator Protective Trip Function)
This document has been appropriately designated as proprietary.
I have personal knowledge of the criteria and procedures utilized by Coaoustion Engineering in designating ir. formation 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 regulatior,, the following is furnished for consideration by the Commission in dcLermining whether the information sought to be withheld from public disclosure, included-in the above referenced document, sL3uld be withheld.
1.
The information sought to be withheld from public disclosure are selected input data and results from the analysis of a Loss of '.oad to a Single Steam Generator event, which is owned and has been held in confidence by Combustion Engineering.
2.
The information consists of test data or other similar data concerning a process, method or component, the application of which results in a substantial competitive advantage to Combustion Engineering.
3.
Tre information is of a type customarily held in confidence by Combustion Engineering and not customarily disclosed to the public.
f Combustion Engineering 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 information in confidence. The details of the aforementioned system were provi;ed to the Nuclear Regulatory Commission via letter DP-537 from F.M. Stern to Frank Schroeder dated December 2,1974.
This system was i
applied in determinir.g 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 under:tanding 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 regu'..cory 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.
I
3-
.).
Development of this information by C-E required thousands of man-hours of effort and tens of thousands of dollars.
To the best of my knowledge and belief a competitor would have to undergo similar expense in
_ generating equiva!ent information.
c.
In order to acquire such information, a competitor would also require considerable time and inconvenience related to development of methodologies and determination of input parameters for Loss of Load to a Single Steam Generator analysis.
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' cost in applying the infc mation and marketing the product to which the information is-applic:ble.
e.
The information consists of selected input data and results from analyses of Calvert Cliffs, Unit 1 Cycle 5 Loss of Load to a Single Steam Generator event, the application of which provides a competitive economic advantage. The availability of such information to ccmpetitors 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 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, f
significant research, ac/elopment, 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 expenditare of resources may enable them to sell at orices
. reflecting significantly lower costs.
Use of the informa' ion by competitors in the international g.
t marketplace would increase their ability 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.
f_t
_r A. E. Sgpefer Director Nuclear Licensing Sworn to before me this day of /\\ & W s M L NL:M y 'h) l'l(; L3 Notary Public
)
P s
Calvert Cliffs Unit 1 Cycle 5 NRC Reload Ouestions Response (Answers on Asymetric Stean Generator Protective Trip Function)
October 31, 1980 G
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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, 4
COMPLETENESS, OR USEFULNESS 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. ASSUMES 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.
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Question 1 In Section 1.0, justify the statement that Loss of Load to one steam generator (LL/ISG) caused by a single main steam isolation valve (MSIV) closure is the most limiting event. What other events were analyzed?
Answer The four asymmetric events considered are:
1.
L ss of Load to one steam generator 2.
Loss of feedwater to one steam generator 3.
Excess load to one stean generator 4.
Excess feedwater to one steam generator.
' Studies such as those documented in CENPD-199-P (Reference 1),
have shown that the Loss of Load to one steam generator event produces by far the largest margin degradation and thus is the most limiting asymmetric event.
Since thic event is most limit-ing, it was the only asyrnetric event analyzed for Cycle 5 to establish the ASGPTF setpoints.
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Question 2 Provide a comparison of the key parameters such as DNBR, CTM, etc.,
for the most limiting event uith and without RPS ASGTPF.
Answer The limiting asynnetric transient is the Loss of Load to one steam generator (LL/ISG) event.
This event was analyzed assuming the existence of an ASGPTF trip for Cycle 5 to determine the Steam Cencrator dif ferential pressure analysis trip setpoint.
Previous analysis assumed a low steam generator level trip (see CENPD-199-P) to determine the margin that nust be maintained by Tech Spec Limiting condi-tions for operation for this and other asymmetric events.
The closure of a single Main Eteam Isolation Valve causes an asymmetric core inlet temperature distribution.
The DNBR and CTM margin degradation during the LL/lSG cvent is largely due t, the increase in hot channel integrated r7/ial peak associated u..h the inlet temperature asymnetry.
Figure 1 presen*- the integrated radial peak increase as a function of the core inlet temperature tilt.
This figure presents both the enveloped data used in the Cycle 5 safety analyses and the Cycle 5 specific data.
Figure 2 presents the core inlet tenperature tilt as a function of time for the LL/ISG cvent initiated at the conditions given in Table 1.
This figure presents the temperature tilt obtained assuming the ASGPTF and the low steam generator level trip intervenes.
The use of the above data in combination with other key parameters listed in Table 1, results in transient minimum DNBR's presented in Table 2.
Table 3 presents the corresponding maximum Peak Linear Heat Generation Rate (PLHGR) obtained during this event.
Tables 4 and 5 present the sequence of events for the LL/lSG event with ASGPTF and with low steam generator water level trip respectively.
As shown in Table 2, the DNBR limit of 1.19 would have been exceeded for the case waich used enveloped data and which did not use ASGPTF. Under these circumstances, either cycle specific data for the integrated radial peak changes as a function of core inlet temperature tilt would have been used or other parameters such as Axial Shape Index band or the initial FR would have been made more restrictive and thereby limiting ocarational flexibility.
Table 3 shows that for Cycle 5, the LL/ISC... tysis based on cycle specific data for the integrated radial peak changes would have shown accept able resulta without imposing further restrictions on opera-tional flexibility. However, the use of cycle specific data would require extensive reanalysis and possibly restrict operational ficxibility for future reload cycles if the data was determined to be more adverse.
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Tables 2 and 3 show that acceptable' resul t s (l.c., DNBR 31.19 and PLIIGR j21.0 KW/ft) with' enveloped data can be obtained-for the LL/lSG cvent provided one can credit the ex*stence of the RPS ASGPTF.
- Thus,
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the ASGPTF enables the use of' envelop.'ng data for the integrated radial p k changes, minimizes future reload cycle analysis and i
provides enhanced plant safety.
The ASGPTF also climinates the asymmetric events from possibly becoming limiting and thereby imposing restrictions on operational flexibility.
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TABI.C 1 KEY PARR4ETERS USED I!: Tilt LL/ ISG EVE:iT Parameter Units Value Core Power FNt 2754 Initial Core Inlet Temperature F
550 Initial RCS Pressure psia 2200 Initial F (Lead bank inserted 25%)
1.67 Axial Shape Index ASI
.18 Initial Core !! ass Flow Rate X10 lbm/hr-ft 133.9 Initial Steam Generator Pressure psia 865 Low Steam Generator Level Inches Below 10.0 Tris Setpoint Feedwater Ring Moderator Temperaturc X10~
iO/ F
-2.5 Coefficient Doppler Multiplier 0.85 Scram Uorth at Trip
%ss
-4.3 Initial Peak Linear Heat KW/ft 16.0 Generator Pate e
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TAltl.1: 2 D!illR RESULTS FOR LL/ ISC EVF.!;T Tine of At Time of Mininun DNBR flinimum Trip Function Minimum DNiiR OT ("F)
AFn DNBR ASGPTF 5.5
[
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[
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1.39 l
Low Stean Generator 10.3
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[
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1.20 Level Trip Low Stean Generator 10.3
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1.09 Level Trip (1)DNBR's calculated using cycle specific data (2)DNBR's calculated using enveloped data 4
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TABLE 3 PLilGR RESULTS FOR LL/ISG EVENT Trip Function Time of PLilGR uT ( F)
PLIIGR ASGPTF( }
5.5
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17.46 Lou Steam Generator 10.3
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18.78 Level Trip Low Steam Gr,rator(
10.3
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19.87 Level Trip tilR's calculated using cycle specific data (2)LilR's calculated using enveloped data 5
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.-SEQUEitCE.0 f EVEllTS TOR LOSS 0 F LOAD TO OilE STER 1-GE!!ERATOR UliH ASGPTF
.i Time (secl Event p'elloint or Value 5
0.0
-Spurious closure of a single main steam
. isolation valve 0.0
, Steam flow from unaffected steani generator
. increases to maintain turbine power 2.6
-ASGPT* setpoint reached (differential pressure) 175 psid 3.2 Duap and typass valves are open 1
3.4
' Safety w.tves open.on isolated, steam generator 1000 psia l
l 3.5 Trip breakers open 4.0,
...__CEAs begin to insert Minimum D:iBR occurs
".l.39 5.5 9.6 Maximum steam generator pressure 1054 psia
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Question,1 j
J Clarify the logic used in the' equation:
1 i
(Figure 1)
P
=uqDNB +
cal r-Tl =T1+kB ca e
Q
=M x (Y, B)
Answer-The calculated TM/LP trip limit is dependent.upon the' measured.
value of core inlet temperature (Teal), axial shape index (Y) and Lthe auctioneered higher of the core neutron power (1) and core thermal power (b). The correlation between core power at the DNB SAFDL for the reactor coolant inlet temperature and RCS ranges of interest is expressed by a linear equation of the form:
P
=3QDNB +
cal +
where:
. QDNB " ^1 1
and:
P
= calculated TM/LP trip limit at the DNB var SAFDL expressed in psia-T,7 = measured reactor coolant inlet temperature ( F)'
c A
= function that defines the variation of over-g power with axial shape index (Y)
QR
= function that defines the variation of over-g power with measured core power (Q) h, D and Y = appropriate constants The signal used-to represent the reactor coolant inlet ' temperature is determined-from the equation:
T
=T~+k B
cal e
c where:
T =' measured cold leg temperature C
kf=calibrationconstant=Off a
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The signal used to represent core power (Q) for the QR1 function is the auctioneered higher o.f neutron power (9), determined from the ex-core detectors, and the core thermal power (B), determined from the OT power calculator (i.e.,
Q=> tax (f,B)).
The actual trip limit (Ptrip) is the higher of the calculated 'll!/LP trip limit and the low pressure trip limit (Pmin)-
The low pressure trip limit is a fixed quantity.
The trip limit (P rip) is compared to the measured reac_ar coolant r, stem pressure t
to generate a reactor trip.
A detailed explanation of the logic and methodology employed to determine the coefficients in the Tif/LP trip system is found in Reference 1.
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Ouestion 4 In Table 2.2.1, provide the supporting analysis for the following:
Iten Functional Allowable No.
Unit Trip Setpoint Values 6
Steam Cencrator 1570 psia 1570 psia Pressure - Low Trip Mannually 1685 psia 1685 psia bypassed
~)a Steam Generator
$135psid
<135 psid Pressure Difference liigh Answer The Steam Line Rupture analysis took credit for a low steam generator pressure trip with an analysis trip setpoint of 548.0 psia.
Allowing for measurement uncertainties, corresponding minimum equipment setpoint to assume a trip at 548 psia is 570.0 psia.
The low steam generator trip manual hypass setpoint of 685.0 psia is to provide operational flexibility and is not credited in the safety analysis. Thus, this setpoint does not impact the results of any Design Basis Event which took credit for a low steam generator pressure trip.
The transients resulting from malfunction to one steam generator (i.e., Loss of Load to one steam generator) took credit for an Asymmetric Steam Generator Protective Trip (i.e., Steam Generator i
Pressure Difference High) with an analysis setpoint of 175 psid.
Allowing for measurement uncertainties, the corresponding mininun equipment setpoint is 135 psid.
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CD;PD-199-P, "C-E Setpoint Methodology," April, 1976.
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