ML20195C169
| ML20195C169 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 10/26/1988 |
| From: | Chrzanowski R COMMONWEALTH EDISON CO. |
| To: | Murley T NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML19297H186 | List: |
| References | |
| 5266K, NUDOCS 8811020382 | |
| Download: ML20195C169 (13) | |
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,,r%. Commonwoahh Edison
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) One Fust National Plaza, Chicago, Ilknois
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O 7 Addr ss Reply tx Post Ofhco Box 767
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October 26, 1988 Mr. Thomas E. Murley U.S. Nuclear Regulatory Commission Washington, DC. 20555 t
Attna Document Control Desk
Subject:
Byron Station Units 1 and 2 Braldwood Station Units 1 and 2 THOT Reduction Program tiRC.DocinLRom. 50-454/455 and 50-416Z111 References (a) September 20, 1988, letter from L.N. 01shan to H.E. Bliss
Dear Mr. Murley:
This letter is in response to the request for additional information in reference (a).
Attachment A contains the proprietary version of the "Addendum to WCAp-11386 Rev. 2, Responses to Questions on T-hot Reduction".
Attachment B contains the non-proprietary version of the same responses.
Attachment C contains a Westinghouse f.pp11 cation for withholding (letter CAW-87-122), Accompany Atfidavit, and Proprietary Information Notice.
Since the "Addendum to WCAP-11386 Rev. 2, Responses to Questions on T-hot Reduction" contains information proprietary to Westinghouse Electric Company, it is supported by an affidavit signed by Westinghouse, the owner of the information. The affidavit sets forth the basis on which the information may be withheld from public disclosure by the Commission and addresses with specificity the considerations listed in paragraph (b) (4) of section 2.790 of the Commission's regulations.
Accordingly, it is respectfully requested that the information which is proprietary to Westinghouse be withheld from public disclosute in accordance with 10CTR Section 2.790 of the Connission's regulations, i
Correspondence with respect to the proprietary aspects of the Application for Withholding or the supporting Westinghouse affidavit should reference hl iM L,'
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PDR ADOCK 05000454 j
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i CAW-87-122 and should be addressed to R.A. Wiesemann, Manager Regulatory and
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Legislative Affairs, Westinghouse Electric Corporation, P.O. Box 355, i
Pittsburgh, Pennsylvania 15230.
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Please direct any questions regarding this matter to this office.
Very truly yours, I
Md7J)
R.A.
rsanowski Nuclear Licensing Administrator i
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Attachments.: (A):
Proprietary "Addendum to WCAP-11386 Rev.
2, Responses to j
Questions on T-hot Reduction" l
(B): Non-Proprietary "Addendum to PCAP-11386 f
Rev. 2, Responses to Questions on T-hot Reduction" r
(C): Westinghouse Application for Withholding h
cca Byron Resident Inspector Braldwood Resident Inspector S. Sands j
NRC Region III Office i
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L ATTACHMENT C Westinghouse Application of Withholding i
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Westinghouse PowerSystems a w:e Electric Corporation snaorm 80:355 PmsDuryiPennsyhna 152300355 Nov. 24, 1987 CAW-87-122 Dr. homas Murley, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Comission Wa.shington, D.C.
20555 APPLICATION FOR WITHHOLDING PROPRIETARY INR)RMATION FROM PUBLIC DISCLO5URE
Subject:
Byron /Braidwood T-hot Reduction Final Licensing Report (WCAP-11386 Rev.2)
Dear D. Murley:
The proprietary material for which withholding is being requested in the enclosed letter by Comonwealth Edison is further ideutified in an affidavit signed by the owner of the proprietary infonnation, Westinghouse Electric Corporation. The CTridavit, which accccpanies this letter, sets forth the basis on which the infonnation may be withheld from public disclosure by the Commission and addresses i
with specificity the considerations listed in paragraph (b)(4) of 10CFR Section 2.790 of the Comission's regulations.
1he proprietary material for which withholding is being requested is of the same technical type as that proprietary material previously sutaitted as Affidavit AW-77-018.
Accon11ngly, th.ts letter authorizes the utilization of the accompanying affidavit i
by em wealth Edison.
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Correspondence with respect to the proprietary aspects of the application for withholding or the Westinghouse affidavit should reference this letter, CAW-87-122, and should be addressed to the undersigned.
l Ve truly yours, 1
dt MM.
L Robert A. Wiesemann,i ager l
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/cker Regulatory & Legislative Affairs Enclosure (s) cc:
E. C. Sv:eaker, Esq.
Ofrice of the General Council, NRC l
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PROPRIETARY INFORMATION NOTICE TRANSMITTED HEREWITH ARE PROPRIETARY AND/0R NON-PROPRIETARY VERSIONS OF DOCUMENTS FURNISHED TO THE NRC IN CONNECTION WITH REQUESTS FOR GENERIC AND/0R PLANT SPECIFIC REVIEW AND APPROVAL, IN ORDER TO CONFORM TO THE REQUIREMENTS OF 10CFR 2.790 0F THE COMMISSION'S REGULATIONS CONCERNING THE PROTECTION OF PROPRIETARY INFORMATION SO SUBMITTED TO THE NRC. THE INFORMATION WHICH IS PROPRIETARY IN THE PROPRIETARY VERSIONS IS CONTAINED WITHIN BRACKETS AND WHERE THE PROPRIETARY INFORMATION HAS BEEN DELETED IN THE NON-PROPRIETARY VERSIONS ONLY THE BRACKETS REMAIN THE INFORMATION THAT WAS CONTAINED WITHIN THE BRACKETS IN THE PROPRIETARY VERSIONS HAVING BEEN DELETED.
THE JUSTIFICATION FOR CLAIMING THE INFORMATION SO DESIGNATED AS PROPRIETARY IS INDICATED IN BOTH VERSIONS BY MEANS OF LOWER CASE LETTERS (a) THROUGH (g) CONTAINED WITHIN PARENTHESES LOCATED AS A SUPERSCRIPT IMMEDIATELY FOLLOWING THE BRACKETS ENCLOSING EACH ITEM OF INFORMATION BEING IDENTIFIED AS PROPRIETARY OR IN THE MARGIN OPPOSITE SUCH INFORMATION. THESE LOWER CASE LETTERS REFER TO THE TYPES OF INFORMATION WESTINGHOUSE CUSTOMARILY HOLOS IN CONFIDENCE IDENTIFIED IN SECTIONS (4)(ii)(a) through (4)(ii)(g) 0F THE AFFIDAVIT ACCOMPANYING THIS TRANSMITTAL PURSUANT TO 10CFR2.790(b)(1).
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I AW-77-18 AFFIDAVIT COMMONWEALTH OF PENNSYLVANIA:
ss COUNTY OF ALLEGHENY:
Before me, the undersigned authority, personally appeared Robert A. Wiesemann, who, being by me duly sworn according to law, deposes and says that he is authorized to execute this Affidavit on behalf of Westingnouse Electric Corporation (~Westingnouse") and that the averments of fact set fo'rth in this Affidavit are true and correct to the best of his knowledge, infonnation, and belief:
hlll Robert A. Wiesemann. Manager Licensing Programs j
$ worn to and subscribed t
beforeime this 1 day of b'n l.
1977.
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Notary Public l
2928
3 AW-77-18 THE NATURE OF THE COMPETITION IN THE NUCLEAR BUSINESS Westinghouse's principal competitors in the nuclear steam supply business are Babcock & Wilcox, Combustion Engineering, and General Electric. The principal U. S. competitors in the nuclvar fuel fabrication business are Babcock & Wilcox, combustion Engineering, Exxon, and General Electric.
With the exception of General Electric, these competitors are new entries in the business with substantially smaller investments in technology.-
Westinghouse also has con. petition from foreign fabricators. This com-petition can drastically affect our ability to obtain contracts in the international market. Specific competitors include ASEA-ATOM (Sweden),
Kraftwerk AEG (Germany). Framatome (France), BNFL (Great Britain). Enusa (Spain), Mitsubishi (Japan), and Fabricazione Nucleari (Italy).
Both the nuclear steam supply and the nuclear fuel fabrication businesses involve high technology, and competition is on the basis of that high technology rather than on price. Only if competition continues based on technology will Westinghouse be able to recover its substantial invest-ments in technology and product development.
EFFECT OF RELEASE OF INFORMATION ON WESTINGHOUSE COMPETITIVE POSITION If, as a matter of general practice, cost or price infonnation or infor-mation about the basis on which Westinghouse makes its business judge-ments were made publicly available, it would have the generai effect of altering the nature of competition from a technology base to a price base. This would change the entire complexion of the business and drive it toward a low investment-low technology development business.
Under such circumstances, those in the business with heavy unrecovered invest-ments in technology such as Westinghouse would have difficulty competing successfully with those who have made relatively small investments since 2-9222
l AW-77-18 business would tend to go to the lowest qualified bidder. The general public would also suffer in that they would be deprived of the benefits of technclogical developmerts that would most likely far exceed any short-term benefits derived from lower prices. Likewi.u,, a general practice of making publicly available infortnation obtained from invest-ments in technology would enable competitors to benefit without having to make comensurate investments. This would stifle the incentive for further investments in technology and drive the business to price-based competition instead of competition on the basis of technology with the same end results as in the case of disclosure of cost or price infor-
- mation, WHAT WESTINGHOUSE SEEKS T0 PROT'ECT i
Westinghouse seeks to protect its ability to recover its investments in:
i (1) Basic data resulting from research and development.
(2) Analytical methods and models.
(3) Details of our designs including margins, tolerances, etc.
(4) The knowledge of what data to present and how to present the data to satisfy NRC licensing requirements. NOTE:
In the current licensing envirorsnent, the capability to obtain licensing approval has become very important in the market-place.
9 AW-77-18 The above identified information is of considerable corxnercial a'dvantage to the competitors of Westinghouse to the extent that it eliminates the need for similar investments in technology.
RELATIONSFIP OF INFORMATION SOUGHT TO BE WITHHELD FROM PUBLIC DISCLOSURE TO WHAT IS SOUGHT TO BE PROTECTED INFORMATION SOUGHT TO BE WITHHELD The infomation sought to be withheld consists of the details of the Westinghouse flow path model, analytical modeling techniques, testing programs, comparison of effects of modified initial cao oressure cal-culation, pump speed calculations, continuous flow path quality calculation 'simiting pump speed factor, and discussion of results.
The release of this infomation would result in the following competitor benefits:
POTEhTIAL ADVAh7 AGES TO COMPETITORS (1) It reduces or eliminates the amount of analysis, research and development work competitors would have to do by providing specific data which by reverse engineering together with other infomation, whether it be their own or that which is made publicly available, enables competitors to derive the results of research and develop-ment work with a much smaller investment of their own resources.
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(2) It enables competitors to learn details of our model, calculations.
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and testing programs.
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(3) It allows competitors to verify their own analytical techniques by using comparative testing arguments and with a much smaller investment of resources. l 6441
'O AW-77-18 (4) It enables competitors to define and justify the scope and contents of their testing programs based on a comparison with an accepted program and thereby reduce their costs.
(5) It would provide competitors with the opportunity to develop a similar model on a time schedule which would allow them to counter Westinghouse in the marketplace.
INVESTMENT BY WESTINGHOUSE IN WHAT IS SOUGHT TO BE PROTECT [0 A considerable amount of highly qualified development effort has been expended over a five year period in formulating the analytical models ind computer programs used to assess energency core cooling system performance during a loss-of-coolant accident. The investment involved in test components, testing facilities, direct labor and computer costs amounts to approximately $3 million dollars. Some specific examples of this effort include testing of pump performance under single and two phase flow conditions, transient testing and analytical formulations for blowdown heat transfer, single and multi-rod dynamic evaluations, and associated code oevelopment and calculations of system effects as they influence emergency core cocling system performance during loss-of-coolant accidents.
It should also be recognized that, in the course of these efforts.
WestinghouJe has. generated additional information regarding emergency core cooling system design bases to improve our product and ultimately enhance our competitive position.
Furthermore, it is felt that the extensive eff ort expended in obtaining comprehensive analytical and experimental information on system and component emergency core cooling system performance could directly affect our sales performance with respect to the Itcensing service for which it is provided.
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O AW-77-18 POTENTIAL HAP.M TO WESTINGHOUSE We believe there is a likelihood of substantial harm to the compe,titive position of Westinghouse if the information sought to be withheld is publicly disclosed, which could result in a minimum loss of approxi-mately $10,000.000 to $12.000.000 annually in potential reload fuel sales and reload emergency core cooling systen analyses.
An example of Westinghouse infomation publicly disclosed and serving to the advantage of our competitors is an instance where information submitted to the NRC by Westinghouse was used by the NRC practically i
verbatim in the issuance of the regulatory guide concerning the rod ejection accident. There was no attempt by Westinghouse to protect snis infomation from disclosure in this instance, but it serves to illus-trate the value which can accrue to competitors from the release of the more sensitive infomation which Westinghouse does seek to protect.
A further example--a licensee, a customer of a Westinghouse competitor, concluded that power spikes due to fuel densification in both the LOCA c
and DNB analyses need not be considered.
In both cases, justification was based upon Westinghouse topical reports. The NRC Staff concluded this was acceptable. This situation was further aggravated by the fact that the licensee had not considered the effects of rod bowing on DNB and LOCA analyses. However, based upon experimental data in another Westinghouse topical report which had been reviewed and accepted by the l
5taff, the licensee was able to eliminate penalties.
Further the deponent sayeth not, t
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l ATTACHMENT B Non-Proprietary "Addendum to'WCAP-11386 Rev.
2, Responses to Questions on T-hot Reduction" t
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-o Addendum to WCAP-ll387 Rev. 2 WESTINGHOUSE CLASS 3 RESPONSES TO NRC QUESTIONS ON T-HOT REDUCTION OCTOBER 1988 1
ATTACHMENT A RESPONSES TO NRC_ QUESTIONS ON T-HOT REDUCTION Question 1:
In Section 3.6 of Attachment C of the above reference, which pertains to the impact of the Thot reduction program on the Technical Specifications, you state that "A Statistical setpoint study performed previously for Byron Units 1 and 2 provided increased margin in total allowance to various Technical Specification related instrumentation setpoints. Based on an evaluation of the sensitivities of the study for the reduced temperature parameters, it has been concluded that the setpoint allowances accounted for in the statistical evaluation remain valid."
Please provide the references for the stated statistical setpoint study and the evaluation. Was this reviewed and approved by the NPC7 What is the value of the increased margin in total allowance to the various Technical Specification related instrument setpoints? Provide the summary of the study for which you state that the statistical evaluation remains valid.
RESPONSE: A statistical setpoint study for protection system setpoints was completed for the Byron and Braidwood Units 1 and 2 in December, 1982 and documents the instrument uncertainties and the safety 1
analysis limits used in the development of the Byron /Braidwood technical specification protection system setpoints. This report has been submitted by Ceco.
4 A combined RTO Bypass Elimination /T-hot Reduction instrument uncertainty analysis was recently completed for the Byron /Braidwood units. Since this is a combined analysis Westinghouse cannot provide specific documentation solely for the T-hot reduction.
It is Westinghouse's judgment that the previous instrument uncertainties determined in the statistical setpoint study are valid for the T hot reduction.
l The value of the increased margin in total allowance to the l
various technical specification related instrument setpoints from the statistical setpoint study is that there is a greater allowance for error before a safety limit is reached.
Question 2:
You have stated in Section 3.1 of Attachment C of the above Reference that both the small break and large break LOCA conditions have been reanalyzed and that the reanalyses are presented in Appendix A of your report. Appendix A contains marked up sections of Chapters 6.2.1.5 and 15.6.4 of the Byron /Braidwood FSAR.
For the large break LOCA you state, in insert 4, that the chopped cosine power shape results in the most severe calculated consequence as required for LOCA analysis in 10 CFR 50 Appendix K.
For the Small break LOCA you state on page 15.6-19 that "Figure 15.6 48 presents the hot rod power shape utiU zed to i
perform the small break analysis presented here. This
l power shape was chosen because it provides an appropriate distributien of power versus core height and also local power is maximized in the upper regions of the reactor core (10 ft. to 12 ft.). This power shape is skewed to the top of the core with the peak local power occurring at the 10.0 ft core elevation".
Please explain how the hot rod power shape was arrived at for both the large and small break LOCA to satisfy the requirements of 10 CFR 50.46 Appendix K which states that,
.... A range of power distribution shapes and peaking factors representing power distributions that may occur over the core lifetime shall be studied and the one selected should be that which results in the most severe calculated consequences....".
RESPONSE: Small break LOCA: Before responding to the question it must be pointed out that Figure 15.6-48 of WCAP ll386 Rev. 2 is in error. That figure mistakenly shows the power shape of the hot assembly average rod and not the hot rod. A revised figure has been provided (Attachment B) which shows the hot rod power shape.
In regards to satisfying the requirements of 10 CFR 50.46 Appendix K, although it is true that Westinghouse has never presented a power shape study for small break for NRC review, the NRC has approved WCAP 9500 A which does show a representative small break power sha >e in Volume 3.
In addition, the power distribution mecianisms which govern the peak clad temperature (PCT) for small break are:
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,)a.c In examining the revised Figure 15.6 48 (Attachment B) as well it is evident that the above criteria as Figure 1 (attached) lso, as evidenced in Figure 1, the hot have been satisfied. A rod power shape used is not a specific power shape which can be expected to occur in the Byron /Braidwood plants wt an envelope of several power shapes which peak at the 10.0 and 10.5 foot elevations, and have much lower power at elevations above 10.5 feet.
Large break LOCA: k. NRC requireeent in the 1981 Evaluation Model (EM) + BASH NRC SER was for Westinghouse to demonstrate that the most limiting power shape was being used in 1981 EM +
BASH 1arge break LOCA analyses. Westinghouse letter
NS NRC 87-3237 (June 22, 1987) to James Lyons of the NRC Technical & Operations Support Branch presented in a Westinghouse proprietary attachment the results of power shape studies for Fq equal to 2.32 and 2.50. This study is also Addendum 1 (Rev.1) to WCAP-10266-P-A. These studies showed the chopped cosine power shape to be most limiting at both peaking factors. Thus the 2.40 peaking factor used for Byron /Braidwood is bounded by this study and the chopped cosine power shape used in the analysis satisfies the requirements of 10 CFR 50.46 and Appendix K to 10 CFR 50.
Question 3:
In Attachment C. Appendix B of the above Reference, the Technical Specification change for Figure 3.2 2 is provided. This figure shows K(Z) normalized Fn(Z) as a function of core height.
In comunts to this Pevision you have stated in Attachment D of Reference 1 that "This revision to the third line segment of the K(Z) curve will allow reactor operation with an increased heat flux hot channel factor at high core location."
In order to compare the results of your analysis with the revised K(Z) curve please provide figures similar to Figure 3.2 2 with the results of your analysis imposed for the power shape. This should include curves of linear heat generation rate (kw/ft) vs. elevation (ft) including core average and hot rod values and the K(Z) limit for the SBLOCA.
RESPONSE: Figure 1 is proviried in response to this question.
Question 4:
On P.6 is a statement that the increases in F and F-delta-HwereaddressedonlyintheLOCAanakysis. Will these increases be addressed for other accident analyses l
where they may affect (1) Ic:a1 power density, (2) minimum DNBR7 RESPONSE: In order to take full advantage of the margin for increased Fg and F-delta H that was built into the LOCA analysis, similar reanalysis in the affected non LOCA transients must be performed. This has not yet been done and therfore changes to the technical specifications to reflect these new values cannot be made.
Question 5:
In Section 3.4 (P.13) on Non-LOCA transients - Please explain why the parameters modified differ as shown below:
19.3 degrees F reduction in nominal RCS Tave (P.13),
19.6 degrees F in Table 2.1-1 (P.5)
RESPONSE: The two temperature values do not represent the same number. The 19.3 degree value on page 13 is the reduction in vessel average temperature. The 19.6 degree value on page 5 is derived from the two values presented for g u t average temperature. The non LOCA transient analyses input the vessel average temperature.
l which show solid (P.31) - No labels are shown on the curves In Figure 3.4 1 j
Question 6:
and dashed lines for curves of delta T vs.
Tave. Please identify what the solid and dashed lines represent.
RESPONSE: Figure 3.4 1 represents the impact of T-hot reduction on the overtemperature and Overpower delta-T trip functions. The solid, somewhat vertical, lines represent the core limits at pressures of (from left to right) 1860, 20rJ 2250, and 2400 psia, respectively. The solid line intersecting the 4 core limit lines represents the steam generator safety valve line.
The somewhat horizontal dashed line at the top of the figure is the protection provided by the Overpower delta-T trip function.
The remaining 4 dashed lines represent the calculated trip setpoints for Overtemperature delta-T at the same four pressures identified above. This is discussed in greater detail in Section 15.0 and Figure 15.0-1 of the Byron /Braidwood FSAR.
Question 7:
In Table 15.6 1 (Sheet 1 of 5) P.15.6 30, why is the event of ' rods begin to drop" (42.6 seconds) listed after the event of 'sinimum DNBR occurs" (43.7 seconds)?
RESPONSE: The descriptions are presented in the correct order, however, the times reported are backwards. Note that this event was not reanalyzed for the T hot reduction; it merely showed up on the same page as part of the LOCA changes.
Question 8:
In Table 15.6 (P. 15.6-35), ' Input parameters used in the ECCS Analysis", there are listing for initial loop flow, inlet and outlet temperature and steam pressure. Reduced and nominal T hot values are given. Whrt are the nominal and reduced T hot values? Provide a background for the values stated and explain why the nominal values differ from the crossed out values used initially.
Is this due to increases in peak linear power and peak;ng factors Fq and Fr? Was the original analysis with no steam generator tube plugging? Does the 18 F reduction in T-het require such a large steam pressure reduction of about 200 PSI from 977 PSIA? Is the safety injection flow input for the ECCS analysis reduced by 5% as mentioned on page 67 RESPONSE: The Nominal and Reduced designations used in Table 15.6 were intended to differentiate between the as designed operating conditions for Byron /Braidwood and the condit<ons creoted by the T hot reduction program. The values appearing in Table 15.6 are numbers generated to support LOCA assumptions. The ' Nominal T het" is 622.3 F and tse "Reductd T hot' is 600 F.
The nominal values appearing in Table 15.6 of h3 '-11386 differ from the previous analysis values for several 4asons. The previous analysis was perfomed with M steam generator tube plugging and used best estimate T-ave to determine T hot and T cold at the LOCA conditions of 10M thermal design flow and 102% of core power. The T-hot reduction analysis again used best estimate T ave, but 98% of thermal design flow and assumed 10% steam J
generator tube plugging. Steam generator tube plugging affects best estimate flow which affects best estimate T ave. A 10%
plugging level assum> tion accounts for about 5 F of the difference seen in tie previous analysis T-hot and the WCAP-11386 analysis. Additionally, the 2% reduction in the thernal design flow assumption accounts for the remaining difference. A decision was made to use 98% of thermal design flow as a hedge against the potential for a flow short fall at the Braidwood units which had not yet operated at the time the T-hot reduction analysis was performed.
The reduction in hot leg temperature from 622.3 F to 600 F does result in the reduction of steam generator secondary pressure from 977 PSIA to 775 PSIA. A rough estimate of the effect can be determined by comparing the change in saturation pressure for the change in cold leg temperature from 560.1 F to 535.1 F.
This change in temperature results in a 206.2 PSI change in saturation pressure which is roughly equivalent to the steam generator pressure change.
Safety injection flow rates were reduced by 5% over the values assumed in the previous analysis. However, most of this margin has been used in a recent safety evaluation to support new pump acceptance curves at Byron 1 for the charging and safety injection pumps. The low head SI (RHR) pumps still retain 5%
margin to the FSAR requirement.
Question 9:
In Table 15.6 3, Page 15.6 36a - Large Break LOCA Results Fuel Cladding Data:
For the column heading Nominal T-hot, why is the temperature 622.3 F instead of 618.4 F7 Is the max ECCS column 'he ECCS flow without 5% reduction in safety injecti, i flow as stattd on page 6 for LOCA accidents?
RESPONSE: The hot leg temperature value of 622.3 F is the nominal value as explained in the answer to question 8.
The difference between 1
622.3 F and 618.4 F due to the LOCA assumptions of 102% power, I
98% thermal design flow and 10% steam generator tube plagging.
Parameters for Byron /Braidwood using 0% steam generator tube l
plugging, thermal design flow and 100% power result in a hot leg temperature 618.4 F.
Thus, 618.4 F would be the expected l
nominal hot leg temperature for Byron /Braidwood at 0% steam I
generator tube plugging and thersal design flow. As tube I
plugging levels increase the hot leg temperature would also increase, approaching 622 F.
I No reduction in maximum ECC5 flow was assumed in the analyses.
l The maximum flows are conservatively high flows based on increased pump head and minimum system resistance and therefore I
l are not realistic.
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Question 10:
In Table 15.6 4, page 15.6 37, - SBLOCA Results Fuel Cladding Data, why is the T hot - 422.3 F instead of 618.4 F as used originally?
RESPONSE: The response to this question is identical to the response for question g part a, that is, the hot leg temperature value of 622.3 F is the nominal value as explained in the answer to question 8.
The difference between 622.3 F and 618.4 F due to the LOCA assumptions of 102% power, 98% thermal design flow and 10% steam generator tube plugging. Parameters for Byron /Braidwood using 0% steam generator tube plugging, thermal design flow and 100% power result in a hot leg temperature of 618.4 F.
Thus, 618.4 F would be the expected nominal hot leg temperature for Byron /Braidwood at 0% steam enerr:.or tube plugging and thermal design flow. As tube p uggiry levels increase the hot leg temperature would also nerease approaching 622 F.
Question 11:
On page 15.6 19, why is there a decrease in the elevation for peak power from 10.5 ft to 10.0 ft.?
RESPONSE: The previous small break LOCA methodology (WFLASH) allowed for analyses to be performed at several actual power shapes peaked to the top of tie core with the limiting results (in terus of PCT) being reported in the FSAR. As stated in the response to question 2 and demonstrated in Figure 1, the power shape used for this analysis using NOTRUMP is an envelope of several power shapes including the actual power which would peak at 10.5 f t.
Also, as can be seen in Figure 1, an actual power shape which would peak at '.0.5 ft, would have a lower linear power at 10.0 ft, than the power shape used for this analysis as well as lower linear power above 10.5 ft.
Question 12:
Have any other Westinghouse plants had a:
a)
Mod of T hot reduction? Which ones?
b)
Mod of 3rd line segment of K(Z) curve removed? Which ones?
RESPONSE: Programs siellar in scope to the Byron /Braidwood T hot reduction have been initiated for D.C. Cook 1 & 2, Indian Point 3 & 4 and V.C. Sussner. The analysis to support this operating mode is still underway for these plants.
Third line segment removal has been incor> orated in the technical specifications by Callaway. Otiers that have had the same analysis perfomed include Diablo Canyon and Trojan, however the Itcensing status of these efforts is not known.
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