ML17332A850
| ML17332A850 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 05/26/1995 |
| From: | Liparulo N WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| To: | Russell W NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML17332A849 | List: |
| References | |
| CAW-95-830, NUDOCS 9507180140 | |
| Download: ML17332A850 (62) | |
Text
Ntestingho use Electric Corporation Energy Systems Nuclear Technology Oivlsion Box 355 Pitlsuurgh Pennsylvania 15230 0355 May 26, 1995 CAW-95-830 Document Control Desk US Nuclear Regulatory Commission Washington, DC 20555 Attention: Mr. WilliamRussell APPLICATIONFOR WITHHOLDINGPROPRIETARY F RMATI N FR BLI DI R
Subject:
"Westinghouse Setpoint Methodology for Protection Systems, Donald C. Cook Unit 2" WCAP-13801 (Proprietary)
Dear Mr. Russell:
'Ihe proprietary information for which withholding is being requested is further identified in Affidavit CAW-95-830 signed by the owner of the proprietary information, Westinghouse Electric Corporation.
The affidavit, which accompanies this letter, 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 10 CFR Section 2.790 of the Commission's regulations.
I Accordingly, this letter authorizes the utilization of the accompanying Affidavitby American Electric Power Service Corporation.
Correspondence with respect to the proprietary aspects of the application for withholding or the Westinghouse affidavit should reference this letter, CAW-95-830, and should be addressed to the undersigned.
Very truly yours, RSL/bbp Enclosures cc:
Kevin Bohrer/NRC (12H5)
N. J. Liparulo, anager Nuclear Safety Regulatory & Licensing Activities 9507180140 950707 PDR ADQCK 05000315 PDR Q
lk
Copyright Notice The reports transmitted herewith each bear a Westinghouse copyright notice.
The NRC is permitted to make the number of copies of the information contained in these reports which are necessary for its internal use in connection with geneiic and plant-specific reviews and approvals as well as the issuance, denial, amendment, transfer, renewal, modification, suspension, revocation, or violation of a license, permit, order, or regulation subject to the requirements of 10 CFR 2.790 regarding restrictions on public disclosure to the extent such information has been identifiied as proprietary by Westinghouse, copyright protection not withstanding.
With respect to the non-proprietary versions of these reports, the NRC is permitted to make the number of copies beyond those necessary for its internal use which are necessary in order to have one copy available for public viewing in the appropriate docket files in the public document room in Washington, DC and in local public document rooms as may be required by NRC regulations if the number of copies submitted is insufficient for this purpose.
Copies made by the NRC must include the copyright notice in all instances and the proprietary notice ifthe original was identified as proprietary.
Proprietary Information Notice Transmitted herewith axe proprietary and/or non-proprietaxy versions of documents furnished to the NRC in connection with requests for generic and/or plant-specific xeview and approval.
In order to conform to the requixements of 10 CPR 2.790 of the Commission's regulations concerning the protection of proprietary information so submitted to the NRC, the infoxmation which is proprietary in the proprietary versions is contained within brackets, and where the proprietary information has been deleted in the non-pxoprietaxy versions, only the brackets Iv xemain (the information that was contained withinthe 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 (f) contained within parentheses located as a superscript immediately followingthe brackets enclosing each item of information being identified as proprietary or in the margin opposite such infoxxnation.
These lower case letters refer to the types ofinformation Westinghouse customarily holds in confidence identified in Sections (4)(ii)(a) through (4)(ii)(f)of the affidavit accompanyingithis transmittal pursuant to 10 CFR 2.790(b)(1).
~t p
CAW-95-830 AFFIDAVIT COMMONWEALTHOF PENNSYLVANIA:
ss COUNTY OF ALLEGHENY:
Before me, the undersigned authority, personally appeared Henry A. Sepp, who, being by me duly sworn according to law, deposes and says that he is authorized to execute this Affidaviton behalf of Westinghouse Electric Corporation ("Westinghouse" ) and that the averments of fact set forth in this Affidavitare true and correct to the best of his knowledge, information, and belief:
Sworn to and subscribed before me this &
day of
, 1995 Henry A. Sepp, Manager Regulatory and Licensing Initiatives NdaNM K,HM~m."-iioM~
Mtwrcevp Bow.<W~
gy Ctm~~
t~~ K, 1
~oa@en ot NoLwes Notary Public l6QC-LtL I:0$2W
'X I
pA CAW-95-830 (1)
I am Manager, Regulatory and Licensing Initiatives, in the Nuclear Technology Division, of the Westinghouse Electric Corporation and as such, I have been specifically delegated the function of reviewing the proprietary information sought to be withheld from public disclosure in connection with nuclear power plant licensing and rulemaking proceedings, and am authorized to apply for its withholding on behalf of the Westinghouse Energy Systems Business Unit.
(2)
I am making this Affidavitin conformance with the provisions of 10CFR Section 2.790 of the Commission's regulations and in conjunction with the Westinghouse application for withholding accompanying this Affidavit.
(3)
I have personal knowledge of the criteria and procedures utilized by the Westinghouse Energy Systems Business Unit in designating information as a trade secret, privileged or as confidential commercial or financial information.
(4)
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 should be withheld.
(i)
The information sought to be withheld from public disclosure is owned and has been held in confidence by Westinghouse.
(ii)
The information is of a type customarily held in confidence by Westinghouse and not customarily disclosed to the public.
Westinghouse 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 application of that system and the substance of that system constitutes Westinghouse policy and provides the rational basis required.
Under that system, information is held in confidence ifit falls in one or more of several types, the release of which might result in the loss of an existing or potential competitive advantage, as follows:
Ib53C RSL 2Ã52&$
CAW-95-830 (a)
The information reveals the distinguishing aspects of a process (or component, structure, tool, method, etc.) where prevention of its use by any of Westinghouse's competitors without license from Westinghouse constitutes a competitive economic advantage over other companies.
(b)
It consists of supporting data, including test data, relative to a process (or component, structure, tool, method, etc.), the application of which data secures a competitive economic advantage, e.g., by optimization or improved marketability.
(c)
Its use by a competitor would reduce his expenditure of resources or improve his competitive position in the design, manufacture, shipment, installation, assurance of quality, or licensing a similar product.
(d)
It reveals cost or price information, production capacities, budget levels, or commercial strategies of Westinghouse, its customers or suppliers.
(e)
It reveals aspects of past, present, or future Westinghouse or customer funded development plans and programs of potential commercial valise to Westinghouse.
(f)
It contains patentable ideas, for which patent protection may be desirable.
There 'are sound policy reasons behind the Westinghouse system which include the following:
(a)
The use of such information by Westinghouse gives Westinghouse a
competitive advantage over its competitors.
It is, therefore, withheld from disclosure to protect the Westinghouse competitive position.
(b)
It is information which is marketable in many ways.
The extent to which such information is available to competitors diminishes the Westinghouse ability to sell products and services involving the use of the information.
p7"
CAW-95-830 (c)
Usp by our competitor would put Westinghouse at a competitive disadvantage by reducing his expenditure of resources at our expense.
(d)
Each component of proprietary information pertinent to a particular competitive advantage is potentially as valuable as the total competitive advantage.
Ifcompetitors acquire components of proprietary information, any one component may be the key to the entire puzzle, thereby depriving Westinghouse of a competitive advantage.
(e)
Unrestricted disclosure would jeopardize the position of prominence of Westinghouse in the world market, and thereby give a market advantage to the competition of those countries.
(f)
The Westinghouse capacity to invest corporate assets in research and development depends upon the success in obtaining and maintaining a competitive advantage.
(iii)
The information is being transmitted to the Commission in confidence and, under the provisions of 10CFR Section 2.790, it is to be received in confidence, by the Commission.
(iv)
The information sought to be protected is not available in public sources or available information has not been previously employed in the same original manner or method to the best of our knowledge and belief.
(v)
The proprietary information sought to be withheld in this submittal is the report entitled "Westinghouse Setpoint Methodology for Protection Systems: D. C. Cook Unit 2", WCAP-13801 (Proprietary), August, 1993, being transmitted by the American Electric Power Service Corporation letter and Application for Withholding Proprietary Information from Public Disclosure, to Document Control Desk, Attention Mr. WilliamT. Russell.
The proprietary information as submitted for use by American Electric Power Service Corporation is expected to be applicable in other licensee submittals in response to certain NRC requirements for justification of continued operation.
ISQC RS Lr4452$95 CAW-95-830 This infonpation is part of that which will enable Westinghouse to:
(a)
Provide documentation of the methods for determination of reactor protection system setpoints.
(b)
Establish applicable methods for treatment of uncertainties used in the development of reactor protection system setpoints.
(c)
Assist the customer to obtain NRC approval.
Further this information has substantial commercial value as follows:
(a)
Westinghouse plans to sell the use of similar information to its customers for purposes of meeting NRC requirements for licensing documentation.
(b)
Westinghouse can sell support and defense of the technology to its customers in the licensing process.
Public disclosure of this proprietary information is likely to cause substantial harm to the competitive position of Westinghouse because it would enhance the ability of competitors to provide similar documentation and licensing defense services for N
commercial power reactors without commensurate expenses.
Also, public disclosure of the information would enable others to use the information to meet NRC requirements for licensing documentation without purchasing the right to use the information.
The development of the technology described in part by the information is the result of applying the results of many years of experience in an intensive Westinghouse effort and the expenditure of a considerable sum of money.
IbQC RSL 5452$ 95
CAW-95-830 In order fit competitors of Westinghouse to duplicate this information, similar technical programs would have to be performed and a significant manpower effort, having the requisite talent and experience, would have to be expended for determining uncertainties used in the development of reactor protection system setpoints.
Further the deponent sayeth not.
ATTACHMENT 3 TO AEP:NRC:1184H2
RESPONSE
TO ITEMS 2.AND 3 WESTINGHOUSE LETTER AEP-95-120, DATED JUNE 14, 1995
Westinghouse Electric Corporation Energy Systems AEP-95-120 Box 355 Pittsburgh Pennsytvania t5230 0355 NTD-NSRLA-OPL-95-295 June 14, 1995 Mr. Mark Ackerman Nuclear Licensing and Fuels Section American Electric Power Service Corporation One Riverside Plaza Columbus, OH 43216-6631 AMERICANELECTRIC POWER SERVICE CORPORATION DONALDC. COOK NUCLEARPLANT Revi ed R o
e to NR S
tern Based I&CAudit
Dear Mr. Ackerman:
Attached for your information and use are the revised responses to two requests for additional information resulting from the NRC System Based I&CAuditof Donald C. Cook Nuclear Plant Units 1 and 2.
Original responses were provided in AEP-95491., The responses were revised to incorporate your
~
comments.
The requests are repeated below:
"Provide a discussion on the exclusion of environmental allowances (pressure, temperature, and seismic) for those functional units/loops considered as back-up or secondary).
For example; pressurizer pressure high reactor trip, low reactor trip, low safety injection, steam generator water level low, level low-low and level high-high, and main steam flow high/feedwater flow low mismatch.
Inspection report item ¹3.1.1."
~
"Discuss the use of containment pressure to detect a steamline break inside containment rather than steam line flow high and its conformance to IEEE 279-1968.
Inspection report item
¹3.2.1b."
AEP-95-120 NTD-NSRLA-OPL-95-295 June 14, 1995 This work was performed under the Licensing and Engineering Blanket Order (AEPSC PO¹ 00684-040-SN) as Task ¹95-006. Ifyou have any questions, please call Ms. Robin Lapides (412-374-5683) or me.
Very truly yours, RSL/bbp Attachment K. F. Matthews Senior Sales Engineer North American Field Sales CC:
D. Malin - AEPSC J. Kingseed - AEPSC V. VanderBurg - AEPSC S. Farlow - AEPSC D. Schmader - AEPSC B. Bastian - AEPSC T. Georgantis - AEPSC E. Lewis - AEPSC ABPSCl 14/NSRLh281L
WESTINGHOUSE PROPRIETARY CLASS 2C Donald C. Cook Nuclear Plant RAI Question 2. Provide a discussion on the exclusion ofenvironmental allowances (pressure, temperature and seismic) for those functional units/loops considered as back-up or secondary.
For example; pressurizer pressure high reactor trip, low reactor trip, low safety injection, steam generator water level low, level low-low and level high-high, and main steam flow high/feedwater flowlow mismatch.
Inspection report item 83.1.1 Suggested Response:
1.0 Introduction The Westinghouse philosophy with respect to protection systems is multi-level, placing emphasis on appropriate design and utilization ofprimary trip and actuation functions with inclusion, to the extent practical, offunctional diversity, i.e., backup trip and actuation functions. It is Westinghouse practice to design the protection system with the primary trip and actuation functions meeting necessary and required design criteria, e.g., redundancy, equipment qualification and testability. Westinghouse verifies through various reviews and aaalyses that the primary trip and actuation functions provide the means ofsatisfying the appropriate criteria for termination and mitigation ofAnticipated Operational Occurrences (AOO) and Design Basis Events (DBE) required as part ofthe normal plant licensing process.
Westinghouse has determined to the extent practicable, for a postulated common mode failure ofthe primary trip or actuation function, that an appropriate and reasonable diverse backup trip and actuation function exists.
However, as the regulations and NRC guidance on the requirements ofdiverse backup functions are vague, Westinghouse has applied a separate set ofcriteria on these functions.
IM)oCS85-370. WPF June l4, l995
WESTINGHOUSE PROPRIETARY CLASS 2C 2.0 Regulations and Reports 2.1 Regulations The primary references cited for regulation in this area for the Donald C. Cook Nuclear Plant are the draft design criteria, noted as Appendix H ofthe UI'SAR, Criterion 20 - Protection Systems Redundancy and Independence and Criterion 23 - Protection Against MultipleDisability for Protection Systems.
Criterion 20 "Redundancy and independence designed into protection systems shall be sufBcient to assure that no single failure or removal Rom service ofany component or channel ofa system willresult in loss ofthe protection function. The redundancy provided shall include, as a minimum, two channels ofprotection for each protection function to be served."
Criterion 23 "The efFects ofadverse conditions to which redundant channels or protection systems might be exposed in common, either under normal conditions or those ofan accident, shall not result in loss ofthe protection function."
2.2 Regulatory Reports A regulatory report issued by the NRC which notes some requirements on diversity design is NUIKG-0493, nA Defense-in-Depth and Diversity Assessment ofthe RESAR-414 Integrated Protection System," issued as part ofthe review ofthe Westinghouse RESAR-414"'esign.
ltlReference Safety Analysis Report - Westinghouse four loop, 3820 MWtNSSS design SAR submitted to the NRC for generic application and approval.
IM)ocs85-370.wp F Junc l4, 1995
WESTINGHOUSE PROPRIETARY CLASS 2C nSufficient diversity should be provided in the design so that, for each anticipated operational occurrence in the design basis... occurring in conjunction with each single CMF" postulated...,
the plant response calculated using conservative analyses should not result in a non-eoolable geometry ofthe core or violation ofthe integrity ofthe primary coolant pressure boundary or violation ofthe integrity ofthe containment."
2.3 Westinghouse Documents One ofthe principle Westinghouse documents supporting the design ofthe protection system is WCAP-7306, "Reactor Protection System Diversity in Westinghouse Pressurized Water Reactors."
This WCAP was issued in 1969 and is a summary ofthe analysis that was performed as part ofWestinghouse commitments made to the AEC and ACRS during meetings held in 1968 and 1969 on protection system design.
This document demonstrates that the protection system design provides adequate functional diversity such that "failed fission product bamersu do not occur as a result ofpostulated initiating events even ifthe protection system primary trip or actuation function is not assumed to actuate during the course ofthe event. Demonstration of this capability was sufBcient to convince the regulatory organization that total andiphysical separation ofthe control and protection systems were not required as part ofthe Westinghouse design.
3.0 Westinghouse Protection System Diversity Bases Westinghouse utilizes five guidelines in determining the acceptability ofthe diversity in the protection system trip and actuation functions. It should be noted that as a general rule no specific protection function is designated as a primary function or a backup function. Instead, each protection function may be a primary actuator for some event or events and may be a backup actuator for other events.
Thus all portions ofthe protection system are classified as 1E and l l Common Mode Failure IM)OCS85-370.WPF June 14, l995
WESTINGHOUSE PROPRIETARY CLASS 2C qualified for up to 103 'F (process racks) or 130 'F (sensor/transmitters) environmental and SSE seismic conditions.
Where necessary as a primary trip or actuation function, sensor/transmitters are qualified for adverse (330 'F) environmental conditions.
a)
Where technically feasible, each AOO and DBE should have a qualified primary and backup (diverse) protection function identified.
b)
The diverse protection function is not required to meet the same licensing criteria as the primary protection function, i.e., a less conservative safety limitmay be applied.
As noted in NUREG-0493, "Suf5cient diversity should be provided in the design so that, for each anticipated operational occurrence in the design basis... occurring in conjunction with each single CMF"'ostulated..., the plant response calculated using conservative analyses should not result in a non-eoolable geometry ofthe core or violation ofthe integrity ofthe primary coolant pressure boundary or violation ofthe integrity ofthe containment."
It is also noted in WCAP-7306, "... the second trip reached (the backup) generally does not prevent the design safety limit&om being exceeded.
In this context, the design safety limit... is itselfa highly conservative limit; exceeding this limitdoes not imply intolerable consequences."
c)
Manual operator action may be assumed as a means ofmeeting the protection system diversity criteria. Various guidelines have been promulgated for this purpose.
For operating plants, the reference cited most often is ANSI/ANS 58.8-1984, "Time Response Design Criteria for Nuclear Safety Related Operation Actions."
Common Mode Failure lADOCS85-370.1VPF lunc l4, l995
WESTINGHOUSE PROPRIETARY CLASS 2C d)
The protection functions identified as diverse protection functions are qualified as Class 1E systems for the environment they are nominally expected to perform in. Functions which are credited as primary actuators for adverse environmental conditions are qualified for that environment and EA terms included in the uncertainty calculations.
It should be noted that for a diverse protection function, Westinghouse generally attempts to utilize a function which is already qualified for the environmental conditions it may experience ifit were the AOO/DBE primary trip or actuation function. Where this is not possible, evaluation may be utilized to estimate the time oftrip or actuation on a best estimate basis which willresult in less severe environmental conditions for the determination ofacceptability ofthe diverse protection function.
e)
The primary protection function inputs, to the extent feasible and practical, shall be derived Rom signals that are a direct measure ofthe desired variables.
The primary protection function is defined as the first protection function whose setpoint is reached and is assumed to mitigate the postulated AOO or DBE.
The diverse protection function inputs may be derived &om indirect measures ofthe desired viariables. A diverse protection function is defined as the protection function 4
whose setpoint is reached but is not assumed as the primary mitigation function for the postulated AOO or DBE. This is consistent with the requirements stated in4EEE 279-1971 Section 4.8.
4.0 Summary From the above, the following can be summarized, 1)
Westinghouse has a primary and backup protection function for each AOO and DBE.
IM)OCS85-370.WPF June l4, l995
WESTINGHOUSE PROPRIETARY CLASS 2C 2) 3)
Diverse protection functions may not meet the same licensing acceptance criteria as the primary protection functions.
Manual operator action may be assumed as a means ofmeeting diversity criteria.
4)
Diverse protection functions are qualified Class 1E systems for their nominal expected environmental conditions.
5)
Diverse protection functions may be derived from indirect measures ofthe desired variables.
In general Westinghouse willattempt to utilize a backup protection function that is environmentally qualified. However, when this is not possible, the time oftrip or actuation willbe evaluated to determine the acceptability ofthe diverse protection function. The inclusion of adverse environmental condition allowances in diverse protection function setpoints is possible, but not considered necessary in Westinghouse setpoint uncertainty calculations.
Although inclusion ofadverse environmental allowances is not required, Westinghouse has evaluated the AOOs and DBEs listed in Chapter 14 ofthe Donald C. Cook Nuclear Plant UFSAR with respect to primary and secondary system response versus the inclusion ofEAiterms. For each AOO or DBE whose primary system response is required to function in adverse environmental conditions, one oftwo evaluation conclusions has been reached:
or
- 1) There exists at least one diverse protection function which is environmentally qualified and includes an EA term (evaluated to be sufficient in magnitude) in the set@oint uncertainty calculation.
- 2) There exists at least one diverse protection function which is located outside ofthe adversely a6ected environs and thus does not require an EA term in the setpoint uncertainty calculation.
IM)OCS85-370.WPF Suae l4. l99$
WESTINGHOUSE PROPRIETARY CLASS 2C e
5.0 Evaluation ofDonald C. Cook Nuclear Plant Protection Functions Westinghouse has reviewed Chapter 14 ofthe Donald C. Cook Nuclear Plant UFSAR and has noted those AOOs and DBEs which generate potentially adverse environmental conditions in the plant regions about the sensor transmitters, impulse lines or instrument cabling. The guidelines used for this evaluation are noted below:
1)
For those events that do not result in a release ofprimary or secondary side coolant, no elevated ambient temperatures are expected and thus Environmental Allowance (EA) terms are not required in the setpoint uncertainty calculations for either a primary or backup protection function.
2)
For those events that result in the release ofprimary or secondary side coolant, elevated ambient temperatures may be expected and an EA term may be appropriate in the setpoint uncertainty calculations.
3)
For secondary side breaks, no significant radiation is expected to be released and thus no C
radiation components are required in the EA terms.
4)
For primary side breaks with significant radiation release potential, radiation components are included in the EA terms.
Generally radiation terms are included for large break LOCA only.
5)
Westinghouse does not perform AOO or DBE safety analyses in coincidence with a seismic event.
Table 1 notes the AOOs and DBEs listed in Chapter 14 ofthe Donald C. Cook Nuclear Plant UFSAR (Column 1) which were evaluated for primary and secondary system response and the expectation for adverse environmental conditions (Column 2). Ifadverse environmental UDOCS85-370. WPF Juno l4. 1995
WESTINGHOUSE PROPRIETARY CLASS 2C conditions are expected, then the primary trip or actuation function identified in the safety analyses is noted (Column 3). Appropriate pages in Chapter 14 ofthe UFSAR are referenced to provide where in the UFSAR the primary trip or actuation function is identified, or can be inferred from the limitingsafety analyses reported.
Possible diverse protection functions are identified in the event the primary function is disabled (Column 4). The location ofthe diverse protection function with respect to the presence ofadverse environmental conditions is noted (Column 5).
Finally, for each possible diverse protection function the presence (or absence) ofan EAterm in the uncertainty calculations is noted (Column 6).
lhDOCS85-370.WP F Jvne l4. 1995
WESTINGHOUSE PROPRIETARY CLASS 2C TABLE I ANTICIPATEDOPERATIONAL OCCURENCE / DESIGN BASIS EVENT (COLUMNI)
RCCA l3ank Withdrawal - Subcritical RCCA Bank Withdrawal - at Power RCCA Misalignment Uncontrolled Boron Dilution Loss ofRCS Flow Startup ofan Inactive RCS Loop Loss ofExternal Load I.oss ofNormal Fcedwater Fecdwater System Malfunction Excessive Load Increase Loss ofOffsite Power Turbine-Generator Overspeed Fuel Handling Accident Waste Liquid Release Waste Gas Release Steam Generator Tube Rupture (COLUMN2)
NO NO NO NO NO NO (COLUMN3)
NO NO NO NO NO NO 80 NO NO ADVERSE PRIMARYPROTECTION CONDITIONS FUNCTIONNOTED IN GENERATED?
SAFETY ANALYSES DIVERSE PROTECTION FUNCTIONS AVAILABLE (COLUMN4)
DIVERSE PROTECTION EA TERM IN FUNCTIONLOCATEDIN DIVERSE (COLUMN5)
(COLUMN6)
ADVERSE ENVIRONMENTS SETPOINT't IaDOCS8S-310.WPF
~
~
0
%ESTINGHOUSE PROPRIETARY CLASS 2C ANTICIPATEDOPERATIONAL OCCURENCE / DESIGN BASIS EVENT (COLUMN I)
Steam Pipe Rupture (core response)-
Inside Containment CONDITIONS FUNCTIONNOTED IN FUNCTIONS GENERATED7 (COLUMN2)
YES SAFETY ANALYSES (COLUMN3)
Steam Flow inTwo AVAILABLE (COLUMN4)
Differential Pressure Steamlines - High coincident Between Two Steamlines-with Low Steamline Pressuret'+t Steam Floivin Two Steamlines - High colnctden'l with Tavg - Low-Low Pressurizer Pressure - Low Reactor Trip Pressurizer Pressure - Low Sl Containment Pressure NIS Power Range
-. High Overtemperature b,T ADVERSE PRIMARYPROTECTION DIVERSE PROTECTION DIVERSE PROTECTION FUNCTIONLOCATEDIN ADVERSE ENVIRONMENT?
(COLUMN5)
NO YES YES YES YES NO YES YES EA TERM IN DIVERSE SETPOINT2 (COLUMN6)
NO YES NO NO NO NO NO I I Steam Flow in Two Steamlines - High coincident xvith Low Steamline Pressure generates Steamline Isolation and SI for Unit I. Low Steamline Pressure by itselfgenerates Steamline Isolation and SI for Uiiit2.
1 ~
I I Unit I - see page 14.2.5-6, Results paragraph 3 of,UFSAR. Unit 2 - see page I4.2.5-8, Results paragraph 3 ofUFSAR.
lA)OCS85-370.WP F 1 l
WESTINGHOUSE PROPRIETARY CLASS 2C ANTICIPATEDOPERATIONAL OCCURrNcr/DESIGN BASIS EVENT (COLUMN I)
(COLUMN2)
(COLUMN3)
ADVERSE PRIMARYPROTECTION CONDITIONS FUNCTIONNOTFD IN GENERATED?
SAFETY ANALYSES DIVERSE PROTECTION FUNCTIONS AVAILABLE (COLUMN4)
Overpower d T FUNCTIONLOCATED IN ADVERSE ENVIRONMENT'/
(COLUMN5)
DIVERSE SETP OINK (COLUMN6)
NO DIVERSE PROTECTION EA TERM IN Steam Pipe Rupture (core response)-
Outside Containment Steam Flow in Two Steamlines - High coincident with Low Steamline Pressure'+"
Steam Flow/Feed Flow Mismatch coincident with Steam Generator Water Level - Low Differential Pressure Behveen Two Steamlines-Steam Flow in Two Steamlines - High coincident with Tavg - Low-Low Pressurizer Pressure - Low Reactor Trip YES/NO YES NO NO NO NO/NO NO NO YES NO NO I 1 Steam Flow in Two Steamlines - High coincident with Low Steamline Pressure generates Steamline Isolation and Sl for Unit 1. Low Steamline Pressure by itself generates Stcamlinc Isolation and Sl for Unit 2.
1 1 Unit 1 - see page 14.2.5-6, Results paragraph 3 ofUFSAR. Unit 2 - see page 14.2.5-8, Results paragraph 3 ofUFSAR.
IM)acm-370.wPF
WESTINGHOVSE PROPRIETARY CLASS 2C ANTICIPATEDOPERATIONAL 0CCUItIINCI!/l)l!SIGNI3ASIS EVENT (COLUMN I)
ADVERSE CONDITIONS GENERATED'COLUMN 2)
PRIMARYPROTECTION FUNCTION NOTED IN SAFETY ANALYSES (COLUMN3)
FUNCTIONS AVAILABLE (COLUMN4)
Pressurizer Prcssure - Low SI FUNCTION LOCATED IN ADVERSE ENVIRONMENT (COLUMN5)
NO DIVERSE PROTECTION DIVERSE PROTECTION EATERM IN DIVERSE SETPOINH (COLUMN6)
YES CRDM Housing Failure - RCCA Ejection YESt't NIS Power Range -
High"'IS Power Range - High Overtemperature 4T Overpower 4T Steam Flow/Feed Flow Mismatch coincident with Steam Generator Water Level - Low Overtemperature 4T Overpower 4T NO NO NO
~
NO/YES NO NO NO NO NO/NO NO NO NO While the CRDM Housing Failure - RCCA Ejection results in some elevation ofambient temperatures, Westinghouse has evaluated the transient and has determined that the event power transient is terminated and reversed by doppler eQects due to heating ofthe fuel in less than two seconds.
The reactor trip noted is confirmatory in nature and occurs in less than tsvo seconds.
No significant elevation ofambient temperature occurs in the short time period ofthe power tfanstcnt.
Unit I - sce page 14.2.6-3, Reactor Protection paragraph I ofUFSAR. Unit 2 - see page 14.2.6-3, Reactor Protection paragraph I ofUFSAR.
tsDOCS85.370.WPF I
~
~
WESTINGHOUSE PROPRIETARY CLASS 2C ANTICIPATEDOPERATIONAL OCCURENCE / DESIGN BASIS EVENT (COLUMN 1)
GENERATED' (COLUMN2)
SAFETY ANALYSES (COLUMN3)
ADVERSE PRIMARYPROTECTION CONDITIONS FUNCTION NOTED IN DIVERSE PROTECTION FUNCTIONS AVAILABLE (COLUMN4)
Pressurizer Pressure - Low Reactor Trip DIVERSE PROTECTION FUNCTIONLOCATED IN EA TERM IN DIVERSE (COLUMN5)
(COLUMN6)
NO ADVERSE ENVIRONMENT7 SETPOINT2 Fecdwatcr Pipe Rupture - Inside Containment Steam Generator Water Level - Low-Lowt "1 Pressurizer Pressure - Low SI Pressurizer Pressure - High Overtemperature 4T Pressurizer Pressure - Low Reactor Trip Pressurizer Pressure - Low SI Steam Flow/Feed Flow Mismatch coincident with Steam Generator Water Level - Low YES YES YES YES/NO YES YES NO NO NO YES NO/NO NO I'
Unit 1 - see page 14.2.8-3, Method ofAnalysis item 7 ofUFSAR. (Note Feedwater Pipe Rupture is not part ofthe licensing basis forUnit I and is provided for information purposes only.) Unit 2 - sec page 14.2.8-4, Method ofAnalysis item G ofUFSAR.
IaDOCS85-370.wPF E
WESTINGHOUSE PROPRIETARY CLASS 2C ANTICIPATEDOPERATIONAL OCCURENCE / DESIGN BASIS EVENT (COLUMN I)
CONDITIONS FUNCTIONNOTED IN GENERATED'I SAFETY ANALYSES (COLUMN2)
(COLUMN3)
FUNCTIONS AVAILABLE (COLUMN4)
DiQerential Pressure Behveen Two Steamlines-High Steam Flow in Two Steamlines - High coincident with Low Steamline Pressure'n'team Flow in Two Steamlines - High coincident with Tavg - Low-Low Containment Pressure ADVERSE PRIMARYPROTECTION DIVERSE PROTECTION DIVERSE PROTECTION FUNCTIONLOCATED IN ADVERSE ENVIRONMENT' (COLUMN5)
NO YES NO YES YES NO EATERM IN DIVERSE SETPOINT7 (COLUMN6)
NO YES YES NO NO Firewater Pipe Rupture - Outside Containment YES Steam Generator Water Level - Low-Lowt "t Pressurizer Pressure - High Overtemperature d T NO NO NO NO I'
See Note [4].
I' Unit I - see page 14.2.8-3, Method ofAnalysis item 7 ofUFSAR. (Note Feedwater Pipe Rupture is not part ofthe licensing basis forUnit I and is provided for information purposes only.) Unit 2 - see page 14.2.84, Method ofAnalysis item G ofUFSAR.
t:il)OCS'95-370.%VPF
WESTINGHOUSE PROPRIETARY CLASS 2C ANTICIPATEDOPERATIONAL OCCl JRI'.NCI'. / Dl'.SIGN BASIS EVENT (COLUMNI)
ADVERSE CONDITIONS GENERATED2 (COLUMN2)
FUNCTION NOTED IN SAFETY ANALYSES (COLUMN3)
FUNCTIONS AVAILABLE (COLUMN4)
Pressurizer Pressure - Low Reactor Trip FUNCTIONLOCATEDIN ADVERSE ENVIRONMENT2 (COLUMN5)
NO PRIMARYPROTECTION DIVERSE PROTECTION DIVERSE PROTECTION EA TERM IN DIVERSE SETPOINT2 (COLUMN6)
NO Pressurizer Pressure - Low Sl Steam Flow/Feed Flow Mismatch coincident with Steam Generator Water Level - Low DIQerential Pressure Between Two Steamlines-NO NO/YES NO NO YES NO/NO NO NO Steam Flow in Two Steamlines - High coincident withLow Steamline Pressure""
NO NO YES YES See note [4].
1:U3OCS85-370.wPF
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WESTINGHOUSE PROPRIETARY CLASS 2C ANTICIPATEDOPERATIONAL OCCURENCE /DESIGN BASIS EVLNT (COLUMN 1)
Small Brcak I.OCA ADVERSE CONDITIONS GENERATED?
(COLUMN2)
YFS"'t FUNCTIONNOTED IN SAFETY ANALYSES (COLUMN3)
FUNCTIONS AVAILABLE (COLUMN4)
Pressurizer Pressure - Low Pressurizer Pressure - Low PRIMARYPROTECTION DIVERSE PROTECTION DIVERSE PROTECTION FUNCTIONLOCATED IN ADVERSE ENVIRONMENT?
(COLUMN5)
YES EATERMIN DIVERSE SETP OINT?
(COLUMN6)
YES Reactor Tript'"
Pressurizer Pressure - Low Slt"t SI Overtemperature 6, T Containment Pressure YES NO NO NO
~
'hile the Small Break LOCAresults in some elevation ofambient temperatures, Westinghouse has evaluated the location ofthe Pressurizer Pressure transmitters inside containment and has determined that the expected ambient temperatures willnot exceed 130 'F by the time ofreactor trip initiation. Thus no EA term is included in thc uncertainty calculation for titc primary reactor trip function for this event.
Unit I - scc pages 14.3.2-11 and 13, Tables 14.3.2-4 and 6 respectively, and Figures 14.3.2-3, 11, 19, 25 and 33 ofUFSAR. Unit 2 - see pages 14.3.2-9, 10, 11 and 15, Tables 14.3.2-1, 2, 3 and 7 respectively, and Figures 14.3.2-2, 11, 19, 27, 35, 43 and 51 ofUFSAR.
laDOCS85-370.WPF j
WESTINGHOUSE PROPRIETARY CLASS 2C 6.0 Conclusion A review ofTable I willnote that for those AOO/DBEs that generate adverse environmental conditions, there is at least one diverse protection function that is either; I) qualified for that environment and includes an EA term in the uncertainty calculation for that function, or 2) is located in an area that is not affected by the event and thus does not experience elevated temperatures requiring the inclusion ofan EA term for that event.
Such a review would also note that for each event there is generally more than one diverse protection function available for backup. It is believed that the requirements ofdraft design criteria 20 and 23 as noted in Appendix H ofthe UFSAR and IEEE-279 are satisfied by the protection system and that adverse environmental allowance terms have been included in the protection function uncertainty calculations when appropriate.
IM)OCS85-370.WPF 1
ATTAAKENT 4 TO AEP:NRC:1184H2
RESPONSE
TO ITEM 4 WESTINGHOUSE LETTER AEP-95-089, DATED MAY 9, 1995 "
qjP '
0,
AEP-95489 Westinghouse Electric Corporation C
Energy Systems Box 355 Pittsburgh Pennsylvania 15230 0355 Mr. Mark Ackerman Nuclear Licensing and Fuels Section American Electric and Power Service Corporation One Riverside Plaza Columbus, Ohio 4321&6631 NTD-NSRLA4PL-95-218 May 9, 1995 AMERICANELECTMC POWER SERVICE CORPORATION DONALDC. COOK NUCLEARPLANTUNITS 1 AND 2 edi f i-1 and Hi-2 ontainmen Pr ure f r LB M/E Rel e
ul i n I i e n
inmen Ref:
- 1. Letter from C. O. Thomas (USNRC) to E. P. Rahe (W), dated August 22, 1983,
Subject:
Acceptance for Referencing of Licensing Topical Report WCAP-8821 (P)/8859 (NP),
"TRANFLO Steam Generator Code Description," and WCAP-8822 (P)/8860(NP), "Mass'and Energy Release Following a Steam Line Rupture."
Dear Mr. Ackerman:
The purpose of this transmittal is to provide a response to a concern raised during an NRC System Based Instrumentation & Controls (SBIC) audit of Donald C. Cook Nuclear Plant Units 1 and 2.
This. work was performed under the Licensing and Engineering Blanket Order (AEPSC POI 00684-040-SN) as Task %5-005.
The NRC concern is repeated below:
"The team was concerned that the use of containment pressure to detect a steam line break inside containment, rather than steam line high flow, did not conform to IEEE 279-1968,
'Criteria for Nuclear Power Plant Protection Systems.'ection 4.8, which requires that, 'to the extent feasible and practical, protection system inputs shall be derived from signals which are direct measures of the desired variables.'ince containment pressure is not a direct variable for steamline break accident inside containment (high steam fiow in a single affected steam line is the direct variable), the team determined that there appeared to be some measure of feasibility and practicality for the licensee to use the direct variable to detect kteamline break."
The above concern is valid ifcore protection is the criterion of interest.
A secondary side process variable should be used for core protection following an assumed secondary line rupture.
For a small steamline break, in which a secondary side process variable would not be actuated, a primary side process variable is used, e.g., safety injection actuation via a low pressurizer pressure signal. A primary side process variable, such as pressurizer pressure, can be assumed as the primary protective function, since demonstrating core protection is the goal.
Containment pressure should be used as the
@ve~re protection function (inside containment breaks only, obviously).
AEPO8/HSRLA218r
g 4t
'1 P
AEP-95489 NTD-NSRLA-OPL-95-218 May 9, 1995 Steamline break mass and energy (M/E) releases to containment are calculated as input to evaluate the overpressurization of the containment.
The high containment pressure functions are used to perform two basic functions, 1) prevent overpressurization of the containment (includes steamline isolation and feedwater isolation to limitmass releases),
and 2) isolates containment (to prevent potential spread of radioactive nuclides).
Since the goal of the evaluation is to demonstrate that the containment pressure boundary is protected, then the containment process variables can be assumed as the primary
~
protective functions, e.g., pressure.
That is totally consistent with IEEE 279 statement on most direct variable.
Thus, the high containment pressure signal gi a direct measure of the desired variable for a steamline break analysis for mass and energy releases inside containment.
Furthermore, Reference 1, which provided the initial NRC SER for the topical report on steamline break mass and energy releases inside containment (and prompted Q to address superheated steam releases via Supplements 1 and 2 of WCAPs 8822(P) and 8860(non-P)), specifically acknowledges:
"For small split breaks, coincidence of high steam flow and low steam pressure willnot occur.
Instead, steam and feedwater isolation willbe initiated based on a higher containment pressure signal."
Therefore, it can be concluded that it is acceptable to credit the containment pressure high and high-high functions for the steamline break analysis for mass and energy releases inside containment.
Ifyou have any questions, please call Ms. Robin Lapides (412-374-5683) or me..
Very truly yours,
/z Keith atthews Senior Sales Engineer Power Systems Field Sales RSL/bbp CC:
T. Georgantis - AEPSC V. VanderBurg - AEPSC E. Lewis - AEPSC S. Farlow - AEPSC B. Bastian - AEPSC AEPOSWNSRLQ18l.
fs pM*
ATTAQBKNT 5 TO AEP:NRC:1184H2
RESPONSE
TO ITEM 5
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ATTACEBKNT 5 TO AEP:NRC'1184H2
RESPONSE
TO ITEM 5 The condensate storage tank level instruments are Foxboro Model N-E13DM differential pressure transmitters.
The equipment qualification report for-.these transmitters is Foxboro/Wyle EQ Test Report 45592-4.
This report shows that the model N-E13DM transmitters are restored to within their Reference
- Accuracy,
+0.5X, with extreme errors of +0.28X/-0.21X following a seismic event.
A copy of Table VIII-3 from the test report is attached.
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iAINE L(III-3 Il(ANSNIIIL)(ER)tOR At(n SPAN Still'I GENERIC SEISNIC IESIS 0
u.
9oi'5 l.9/ J I I 50 2.912 75
).9/I Ibn 4.9¹s spm( 4.0?l 0
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?5 2.u?s I 2
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- 5. (NII SPA¹ ).9J(I n
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? 5 2.UIN)
I I Su 2.99U 15 3.963 ion
- 4. 96)
Sl'A¹ 1.961 U. 9)u I.9/1
- 2. 910
- 3. 919 4.iJRG a.ggg 2.O23
).0?8 4.U20 5.0M) u.'J J&
- 2. (N)I
- 2. 991
- 3. M4 4.965 u.?0 a.gci o.uz 0.13 1.9/4 0.16
-0.09 2.912
-0.04
-Q.nl 3.961
-0.45 0.¹2
-U.lo I.ouo
-0.08 0.51 2.021 0.46 0.65 3.027 0.63 0.46 4.UI)
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a.no o.98s o.?6
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-0.04 2.990
-0.01 0.06 3.963 0.08
-0.05 5-UUE N
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5-06E I.n.
oF p(IE-'Ac(I Axis x
IEsls IIU. SPAll SE IS)IIC UP EARO(t INNN( fRAIN\\
5-086 1E 515 AVERAGE 0 J6/
I.g)4
- 2. 971
- 1. 9/0 4.966 4.019 I.ouo 2.022 3.028 4.Q19
- 5. (N)0
- 4. (NN) 0.99G 2.001 2.991 3.984 4.985 3.969 1ESI IN EACII AXI'5 Rut( I UP ANO SPAN QSI ]Q
- 0. 12 0.16
-a.'o&
-a.'zl 0.02
-0.10
-0.08 Q.61
- 0. 65 Q.44
-0. 01 n.'n5
-0.21
-0.04 0.06
-a.os 0.05 n.gr4 1.962 2.976 3.978 4'.996 0.994
- 2. 015 3.019 4.012 4.993 0.996 2.001 2.992 3.965 4.965 '
Ll(AUR I-SSE O.05 0.35 0.06
'0.0) 0.27 0.959 I. 914 2.916 3.974
-0.23
- n. 11 0.43 0.26
-0.20 0.991
. 2.016 3.020 4.011
- 0. 00
-0.21
-0.06 0.03
-0.05 0.997 2.00L 2.992 3.985 I-SSE DESI RUN ERA(N I nu(¹l R
LRROA
-0.0)
- 0. 16
- 0. II
-0 ~ 13
-0.25 0.34 0.45 0.24
-0.03
-0.21
-0.06 0.0) 0.959 1.963 2.977 3.976 4.9¹6 0.99)
- 2. 016 3'.al 9 4.009 4.990
-0.07 0.969 0.38 1.978
- o. ag 2'.916
-0.06 3.963 0.02
-0.25 0.992 0.34 2.011 Q.4 I 3.021 0.19 4.010
-0.28 U. I)
- 0. 969
- 0. 25 I.913 0.0&
2.977
-0.40 3.971 4.989
-0.28 0.992 0.36 2 ~ 017 O.'48 3'.O22 0.21 4.010 4.989 0.997 2.001 2.993 3.965 4.965
-0.03 0.996,
-0.21 2.000
-0.09 2.991 0.03 3.985
-0.05 0.00 0.996
-a'.18 z.oOi
-0.04 2.992 0.01 3.98S 4.966 I-SSE I-SSE I-SSE IES1 1ESI IE51 Il(LN 2 X
Rutl 2 6
RUN 3 UP EIUIOR I)0((N EARSl UP
- 0. 11
- 0. I 3 n.'og
-0. 16
- 0. 10 o.g&4 o.us
- 1. 914
- 0. 16
- 2. 960 O. 16
- 3. 912
-0. I8
-0.28 0.993
-0.25 0.36 2.018 0.'19 0.50 3.021 0.48 Q.?I 4.011 0.24
-o.la Q.on 0.997
-0.03
-0.21 2.001
-0.21
-0.06 2.991
-0.04 0.03 3.984 0.06
-0.08 I-SSE LESI Rutl 3 EAAoA one(
EAAUR I-SSL IES I AVERAGE 0 964 l.971 2.917
- 3. 913 4.990 4.0?6 U.99) 2.017
).u20 4.ul I 4.991 3.996 U.991 2.uul 2.992 3.985 4.965 3.986 IAlt(xt A((U SPA(I Still'
-I u.us cD 0.? I u.og
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-O.OS O.ul 0
0,99II zs 2.'004 Su 3.UII)
/ib 4 ~ Ixl')
IIN) l.'t(PJ SI'h¹ 4.uul U. 99) 2.000
). (XI) 4.0UI 4.9go
-0.12 0.993 u.'a4 z.aoo 0.2l 3.00&
0.?I 4.uuci
-U.n)
-U. Iz a'.o4
- u. 19 n'. in 0.993 2.000
- 3. (N)7 4.(N)7 4.996 4.001
-0. 12 n'.o4
- 0. 21 u.? I
-U.OI 0,05 0.991 I.996 1.004 4.005 4 991
-0.11
-0.01 0.14 n.'ic
-U. IS 0.991 1.9M l.aal
- 4. (x))
0.11
-O.OL O'.ll 0.>>
0.99L 1.999 3.005 4.005 4.993
-0.17 0.99L 0.02 1.998 Q.l&
3.003 U.IG 4.uul
-0.15
-O.I7 0.991
-0.01 1.998
- 0. II l.004 n'. iI 4'.(x)4 4.99)
-0.11 0.991
-0.17
-0.01 1.9M
-0.01 a.'14
).nnl a.'ll Q.ll 4.(N))
U.ll
-0.15 0.991 1.996
- 3. (NI4 4.IN)4 4.'PJ I 4.002
-0. 17
-a.'ol 0.14 0.12
-u.ls U.02 U
Q.964
?5
- 2. (NIO
) 5 SI)
).OI I 15 4.ulb Iuo S.ull 5? at C.u?7 Q.98S 2.0¹2
).als 4.U21 5.016 0.02 0.985 0.02 0.28 2.000 0.23 0.43 1.012 0.36 0.42 4.01U U.)4
- u. 12 0.965 2'.001 3.014
- 4. U? I) 5.016 4.0)l 0.02 0.25 0.984 2.004
- 0. 41,
- 3. QI8 0.39
~
4.U2&
O. 12 5.0?2 0.10 0.33
- 0. 51 0.54 0.27 U.964 2.001 3.015 4.023 OoOO 0,25 0.43 0.41 0.964 2.004 3.016 4.025 5.022 L
0 00 0.984
- 0. 33 2.ML
- 0. 51 3,015 Q.52 4.023 U.27 0.00 0.984 0.25 2.004 0.4) 3.019 Q.47 4.u?G 5.021 O.UU 0.985 U.O2 0.33 2.002 0.28 0.5) 3.015 0.4) 0.54 4.024 0.49 0.30 0.984 2.(x))
3.UI) 4.025 5.022 4.036
- u. (x)
- 0. 3()
U. 48 u.bz U. 21
- 0. 21 I:9iI:
0 iIpuIs are In VOC.
N Error ls N oi ca>>bra(ed span.
'<< li span poIIIL vol(ages are averaged Iroia Lbe 3-run ca>>brailon cbeck.
PfM ~
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ATTACHMENT 6 TO AEP:NRC:1184H2
RESPONSE
TO ITEM 6.A WESTINGHOUSE LETTER AEP-95-090, DATED MAY 9, 1995
)
AEP-95490 Westinghouse Electric Corporation Energy Systems Box 355 Pittsbutgh Pennsylvania 15230 0355 Mr. Mark Ackerman Nuclear Licensing and Fuels Section American Electric and Power Service Corporation One Riverside Plaza Columbus, Ohio 432164631 NTD-NSRLA4PL-95-219 May 9, 1995 AMERICANELECTRIC POWER SERVICE CORPORATION DONALD C. COOK NUCLEARPLANT UNITS 1 AND 2 Envir nmental All wance Error for utside n
inmen In me ti n
Dear Mr. Ackerman:
The purpose of this transmittal is to provide a response to a request for additional information resulting from the NRC System Based Instrumentation Ec Controls (SBIC) audit of Donald C. Cook Nuclear Plant Units 1 and 2. This work was performed under the Licensing and Engineering Blanket Order (AEPSC POtIt 00684-040-SN) as Task %5%05.
The request is repeated below:
V "Discuss the lack of an environmental allowance for cable and transmitters located outside containment.
It is noted that for post accident monitoring and emergency response guidelines an environmental allowance is included for instruments and cable associated with harsh environments inside containment only."
An inherent assumption in the Donald C. Cook Nuclear Plant safety analysis and licensing basis is the requirement that instrumentation environmental errors which are a direct result of a design basis event be specifically addressed in the safety system setpoints for reactor trip and safeguards acbiation that are required to mitigate the consequences of that event.
Consequently, the Westinghouse Setpoint Methodology for Protection Systems - Donald C. Cook Nuclear Plant Units 1 &2 (WCAPS 13055 and 13801) incorporates transmitter environmental allowances (EA's) and insulation resistance (IR) degradation errors for all functions that are credited in the plant safety analysis for desi@ basis events where the cables or transmitters could potentially be exposed to harsh environmental conditions, regardless of whether the instrumentation is located inside or outside containment.
In contrast to the above approach, for post accident monitoring in conjunction with the Westinghouse Owner's Group Emergency Response Guidelines (WOG ERGs),
provisions are made to accommodate transmitter EA and IR degradation errors associated with harsh conditions ~in ide containment only. The ERGs instruct the control room staff to use adverse containment setpoints when predefined limits on measured containment parameters (typically pressure and radiation) are exceeded.
Thus, there is no provision in the ERGs to specifically account for the effect on instrument readings due to breaks outside containment.
AHP090/NSRIA219l,
AEP-95490 NTD-NSRLA-OPL-95-219 May 9, 1995 This philosophy of accommodating EA terms for inside containment releases only was addressed by the WOG during the development of the ERGs.
The safety benefit of including outside containment EA's was evaluated and weighed against the relative impracticality of identifying a mechanism to discriminate between normal and harsh conditions outside containment.
The decision to not accommodate outside containment environmental errors was considered to be acceptable by the WOG and the NRC, as evidenced by their approval of the ERGs.
The basis for this acceptability is discussed below.
Although it is recognized that additional instrument errors due to environmental effects may at times be present for outside containment variables, the impact on the utilization of the ERGs for accident mitigation is small based on three primary considerations:
- 1. Ifenvironmental uncertainties were to exist as a result of an outside containment release, there generally exists diverse instruments located inside containment which would be unaffected by environmental conditions outside containment.
Examples include core exit thermocouples (inside) which are diverse to RVLIS (outside) for detecting inadequate core cooling, or steam generator water level (inside) which is diverse to auxiliary feedwater flow (outside) for assessing heat sink.
- 2. Since instrumentation located outside containment is generally not installed in a contained location, environmental errors due to outside containment releases are of a shorter duration compared to inside containment instrumentation and would tend to come and go during the course of an accident.
- 3. Ifoutside containment variables are exposed to harsh conditions, the resulting errors are often small relative to their use in the ERGs for gross indication, trending, etc.
In summary, although transmitter or cable IR degradation environmental errors could potentially exist for instrumentation located outside containment, such errors have been-evaluated on a generic basis with the conclusion that there is an insignificant impact on safety ifthey are not included in procedure setpoints.
Ifyou have any questions, please call Ms. Robin Lapides (412-374-5683) or me.
Very truly yours, RSL/bbp Keith
. Ma ews Senior Sales Engineer Power Systems Field Sales cc:
T. Georgantis - AEPSC S. Farlow - AEPSC V. VanderBurg - AEPSC B. Bastian - AEPSC E. Lewis - AEPSC D. Schmader - AEPSC AEP090/NSRLA2l9l
ATTACHMENT 7 TO AEP:NRC:1184H2
RESPONSE
TO ITEM 7 WCAP 7306
h,
(