ML20046C043
| ML20046C043 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 07/30/1993 |
| From: | Denton R BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TAC-M85893, TAC-M85960, NUDOCS 9308090144 | |
| Download: ML20046C043 (32) | |
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M BALTIMORE GAS AND ELECTRIC I
l 1650 CALVERT CLIFFS PARKWAY. LUSBY, MARYLAND 20657-4702 i
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RoetnT E. DENTON
{
VICE PRESIDENT l
Nuccan tuta*'
July 30,1993 (4io) reo-44ss j
U. S. Nuclear Regulatory Commission Washington,DC 20555
)
i ATTENTION:
Document Control Desk j
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 Response to Requests for Additional Information Concerning the
Integrated Plant Assessment Methodology, Volume 1: Systems, Structures and Components Screenine" (TAC Nos. M85893: M85960)
REFERENCE:
(a)
Ixtter from Ms. R. L Nease (NRC) to Mr. R. E. Denton (BG&E),
dated June 1,
1993, Response to Requests for Additional Information;" Integrated Plant Assessment Methodology, Volume 1:
Systems, Structures and Components Screening" I
In Reference (a), the NRC requested additionalinformation on various aspects of our methodology and procedures for determining those systems, structures and components that are important to license renewal. Enclosure (1) contains our responses to these questions.
In Reference (a), you also asked us to clarify our request for the NRC to resiew the methodology, procedures and submitted results of our Integrated Plant Assessment Methodology. We have decided to revise our original request. Our revised request is that you review and approve only the methodology of our Integrated Plant Assessment. We do not request your review and approval of the attachments to the methodology. We do, however, recommend that you utilize them as necessary in determining your conclusions concerning the methodology.
Should you have any further questions regarding this matter, we will be pleased to discuss them with you.
Very trulyyours,
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Document Control Desk July 30,1993 Page 2 cc:
D. A. Brune, Esquire J. E. Silberg, Esquire R. A. Capra, NRC D. G. Mcdonald, Jr., NRC i
T. T. Martin, NRC
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P. R. Wilson, NRC R. L Nease, NRC R. I. McLean, DNR J. H. Walter, PSC b
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IIALTIMORE GAS AND ELECTRIC COMPANY (llG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT MIXIlODOLOGY l
SYSTEMS, STRUCTURES AND COMPONENTS NRC Ouestion No. I Figure I-1 does not describe the integratedplant assessment (IPA) as stated on 1-2, but illustrates a jlow path. The figure seems to relate the IPA process to potential management decisions associated with i
updating the Final Safety Analysis Report (FSAR) or determining whether to submit a license renewal application. 1%at is thisjigure attempting to describe? (Page I-5)
IIG&E Response i
The figure illustrates the flow of the IPA process rather than describing the process. The text of the methodology, Section 1.1, will be changed as shown below.
i Figure 1-1 illustrates the flow path of the Integrated Plant Assessment for Aging, which is required by 10 CFR 54.21, as that process is implemented at Calvert Cliffs Nuclear Power I
Plant (CCNPP). Two of the IPA tasks--specifically, important to licen e renewal (ITLR)
System and Structures Screening, and ITLR Component Screening--are the focus of this methodology.
l The figure is intended to provide an overview of how the CCNPP IPA process interfaces with other activities onsite to produce the required documentation for a License Renewal application. Further, the figure shows how the processes described in both Volume 1 and Volume 2 of the CCNPP IPA Methodology relate to each other.
NRC Ouestion No. 2 in the Integrated Flow Diagram (Figure I-1), explain why the bar indicating the need to review the current licensing basis is not connected to the bar that begins the initial systems' screening step. Doesn't 7
the development of the screening tools necessitate the review of specific licensing basis documents?
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Please clarify the use of the current licensing basis in the systems screening step. (Page 1-5)
IlG&E Resrxmse In Figure I-1 of the methodology, the box indicating the need to review the current licensing basis (CLB) should be connected to the box that begins the initial systems screening. An arrow will be added to the figure to show this connection.
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HALTIMORE GAS AND ELECTRIC COMPANY (11G&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS The development of the screening tools does require review of CLB documents. Section 2.2, page 11-8, of the methodology describes the use of the CLB in screening. Subsection 3.3 and all ofits subparagraphs identify the portions of the CLB used in creation of each screening tool.
i NRC Ouestion No.3 Figure 2-1 indicates that only those structures that are Class 1 are ITLR. What does the shaded octagonalon Figure 2-1 mean? (Page11-17)
IlG&E Resrxmse Figure II-1 incorrectly implies that only structures which are Class 1 are ITLR. The ITLR screening tools associated with all four ITLR criteria are reviewed to determine whether any of the ITLR functions are performed by either systems or structures. Sections 3.4.1 through 3.4.3 describe these steps in more detail.
Figure 11-1 will be modified to clarify that the Class 1 check is an additional check performed for structures, rather than the only check.
A specific step is not included in the process to determine if a structure contains equipment mounted in accordance with II/I design criteria. Such a structure would be considered ITLR; however, a check i
of the BG&E Q-List Manual revealed that equipment required to be mounted in accordance with l
II/I design criteria is all located within Class 1 structures. Consequently, no additional structures or functions would be determined by the addition of this step. For any Class 1 structure, the component i
level screening procedure for structures checks to determine whether any equipment is mounted in accordance with II/I design requirements within that structure. See Section 4.2.2 for a detailed discussion of this structural function identification step of the component level screening process for structures.
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l IIALTIMORE GAS AND ELECTRIC COMPANY (IIG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS i
i NRC Ouestion No. 4 The report directs an evaluator to review the current licensing basis in docketed correspondence (CLBID). Are there guidelines to support this activity? Erplain what databases are available for reviewing the CLB/D and how an evaluator would search the CLBfor a specific topic. (Page Illa)
IIG&E Response The screening methodology originally included the contingency of referring to docketed correspondence when necessary to obtain information needed for the screening process. Ilowever, during the screening of several early systems, no new information was obtained by performing such a review. Standard site reference documents provided sufficient information for use in the screening process. Consequently, the conclusion was made that routine, system-by-system reviews of licensing I
correspondence does not produce any additional information related to ITLR functions and, therefore, should not be included as a step in the ITLR screening process. The term "CLB/D" was left in the screening methodology to indicate that review of licensing correspondence would be included in the screening process should the need arise in the future to do so.
i However, as a result of the above discussion, BG&E has determined that the term CLB/D should be climinated from the methodology in order to avoid future confusion on this topic. Therefore the following changes will be made to the methodology:
i 1.
Section 2.2 will be replaced with the paragraph shown below.
l The screening process relies on documents containing portions of the CLB to support screening decisions, e.g., is an System, Structure and Component (SSC) ITLR. and why?
Such documents include, but are not limited to, the Updated Final Safety Analysis Report (UFSAR) [4]; Technical Specifications [5]; the 0-List Manual [6]; and responses to fire i
protection, anticipated transient without scram (ATWS), station blackout (SBO), pressurized thermal shock (PTS), and environmental qualification (EQ) regulations [15,16,17,20, 21, 24,25]. These source documents are used in conjunction with the screening criteria to identify ITLR systems and structures, their ITLR functions and the ITLR components required to support those ITLR functions.
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HALTIMORE GAS AND ELECTRIC COMPANY (BG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METIlODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS 2.
Source document 26 will be deleted from Table 2-1.
3.
He first paragraph of Section 3.2 will be reworded as follows:
The identification of the system and structure conceptual boundaries and function (s) is accomplished by resiewing the CCNPP UFSAR [4], Technical Specifications [5], and System Descriptions [9], as well as conducting interviews with experienced plant personnel.
4.
He last paragraph of Section 3.3.1.1 will be revised as follows:
All systems and functions identified in the Design Basis Event (DBE) and vital auxiliaries flow charts are coded (by shading) to identify the source document (s) from which they were obtained (i.e., UFSAR,0-List Manual, or both).
5.
He first sentence of Section 3.3.2.5 will be modified as follows:
The SBO Analysis [24] is reviewed to identify systems and structures listed in the SBO Analysis which are relied on during the " coping duration" phase of an SBO event.
6.
Figures 2-1 and 2-2 will be updated so that they do not explicitly show the CLB/D as a source of screening information.
r NRC Ouestion No. 5 H hat controls will be established to ensure that changes made after screening is completed to documents referenced in this screening report will be reviewedforimpact on the license renewalscope? (Page 11-8)
I BG&E Response Before submittal of any license renewal application, the screening results will be reviewed for the impact of source document changes on screening results. Integrated plant. assessment results will be updated as appropriate. If a license renewal application is submitted by BG&E and approved, the list of ITLR components will be maintained using existing site processes for maintaining the j
subcategories which make up the list of ITLR components, whenever possible. For example, the O-1 List process for maintaining safety-related equipment will provide the mechanism for maintaining 4
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.4 HALTIh10RE GAS AND ELECTRIC COh1PANY (BG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION i
INTEGRATED PLANT ASSESSh1ENT hiETIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS ITLR Criterion 1 SSCs. If such a control process does not currently exist for specific subcategories of ITLR equipment, a process similar to the O-List will be established for these subcategories.
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NRC Ouestinn No. 6 The methodology refers to and categorizes source documents as high priority, medium priority or low l
priority. Erplain how the source document hierarchy will be used. Provide examples of the types of
.i documents included in each of the three categories. (Pages 11-9 and 11-10)
IIG&E Restxmse The source document hierarchy serves as a guideline to assist an engineer in determining which source documents should be chosen as the primary references for tasks in the IPA. Whenever the information needed to complete an IPA step is available in a document which has been previously reviewed and approved by the NRC, such a document would serve as the preferred reference. If needed information is only available in medium or low priority documents, these documents would serve as the reference for the IPA step. When information in a low priority document is relied on for an IPA determination (such as whether a structure or component is ITLR), appropriate controls over this information would have to be established in accordance with existing site document control procedures. To date, low priority documents have not been used for ITLR determinations in the screening process.
All information comes from either medium or high priority documents.
Additionally, a complete list of the references used to perform each screening task is included with each screening result.
As originally written, Section 2.4 represented general guidance to Life Cycle Management Program personnel concerning how source documents are to be used throughout the implementation of the IPA process rather than specific information for implementing step 54.21(a)(1) and (2) of the IPA.
Therefore,it has been determined that this general guidance is not appropriate in this methodology.
The original Section 2.4 and references to this section will be deleted from the methodology and subsequent sections will be renumbered.
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HALTIMORE GAS AND ELECTRIC COMPANY (BG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS NRC Ouestion No. 7 lAs originally written,] Section 2.4 discusses source document identificatioi, and lists examples of source documents in order ofpriority. Table 2-1 lists the source documents. Is Table 2-1 a complete listing ofsource documents? (Pages 11-11,11-12,11-20 and 11-21)
HG&E Resmmse As originally written, Section 2.4 did not represent a complete list of source documents used in the IPA. This section contained examples of source documents that might be used during the steps of l
the IPA process in order to demonstrate the life cycle management information hierarchy. Per BG&E response to Question 6 above, Section 2.4 will be deleted from the methodology.
- 1 The source document listing provided in Table 2-1 of the methodology represents a complete list of the references used to develop Volume 1 of the methodology. It does not necessarily contain the -
references used to perform the screening. A complete list of the references used to perform each screening task is included with each screening result.
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The following note will be added to Table 2-L l
This list of documents represents the sources used for developing the IPA Methodology Volume 1.
l NRC Ouestion No. 8 Industry reports, although they have not been approved by the NRC, are listed as high priority documents for use in identifying susceptibility to age-related degradation (ARD). Provide specific examples of how the industry repons were used in the preparation of the documents submitted to date.
(Page11-11)
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ILG&E Resmmse Industry reports were not used as the basis for decisions during the screening process described in j
this volume of the IPA methodology.
Per BG&E response to Question 6 above, Section 2.4 has been deleted from the methodology.
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HALTIMORE GAS AND ELECTRIC COMPANY (BG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS NRC Ouestion No. 9 in defining the scope of equipment important to license renewal, the proposed methodolog does not discuss offsite or external hazards that are desi;p basis events. The only design basis external event appears to be a seismic event. Ilow does the methodolog incorpomte the treatment ofoffsite or external events into the development of the list of systems structures important to license renewal? Identify th:
specific accidents or events considered and where in the methodolog they are reviewed. If these events are not considered, provide the basis for not incorImrating these design basis accidents into the methodolog. (Pages 111-1 through 13)
BG&E Response The methodology incorporates screening of external events by screening Class 1 structures as ITLR.
This screening step is described in paragraph 3.4.1.2, page III-12, of the methodology. Class 1 structures at CCNPP are designed to withstand seismic and tornado external events as well as other external events for specific structures. [UFSAR, Appendix 5A, Structural Design Basis]
The component level screening process for structures includes a review of UFSAR Chapters 5 and SA to determine the actual design requirements associated with the Class I criterion for the l
structure being screened. During this process, the structural components associated with mitigating the effects of the external events included in the structure's design basis are identified and associated..
with the appropriate structure ITI.R function. See Section 4.2.2 for more details on this step of the process.
To more clearly address how external events are handled, the following changes will be made to the methodology.
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The first paragraph of Section 3.3.1.1 will be changed as shown below:
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The CCNPP UFSAR Chapter 14 Design Basis Event accident analyses listed below are reviewed.
This list contains both design basis accidents and anticipated operational occurrences. No external events are analyzed in Chapter 14 of the CCNPP UFSAR. All structures designed to withstand DBE external events are designated as Class 1 structures at CCNPP and Class 1 structures are screened as ITLR (Section 3.4.1.2).
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IIALTIMORE GAS AND ELECTRIC COMPANY (IlG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS 2.
The first paragraph of Section 4.2.2 will be replaced with the following discussion:
The systems and structures screening process identifies some structures as ITLR because they are designed to Class 1 riteria or because they are required for fire protection purposes. Unlike the screening results for systems, the Class 1 structure ITLR determination does not actually reveal a great deal about the ITLR functions of the structure. Therefore, during the component level screening, the evaluator reviews Chapter 5 and 5A of the UFSAR to determine specific structure design basis information, such as which external events the structure is designed to withstand and which structural components contribute to these functions.
NRC Ouestion No.10 The initiallist ofsystemsfor the identification ofsystems and structures ITLR was developed using the
" Control of Master Equipment List." However, based on its position on Page 11-11, this would be considered a low priority document. Ilhy is the Master Equipment List considered a low priority document? (Page111-1)
IIG&E Response The Master Equipment List is a separate reference from the procedure entitled, " Control of the Master Equipment List." The Master Equipment List contains information about safety-related and non-safety-related components in a database format. Controls for the safety-related portions of the Master Equipment List are provided by the 0-List Manual and other controlled procedures which govern the 0-List. When the project to upgrade the Master Equipment List and its controlling procedure are complete, the Master Equipment List will constitute a medium priority document.
As discussed in the response to Question 5, the list of systems and structures which was the starting point for the IPA will be reviewed to incorporate changes prior to any License Renewal application submittal. Note that the discussion of the information hierarchy referred to in this question will be deleted from the methodology in response to Question 6.
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IIALTIMORE GAS AND ELECTRIC COMPANY (IIG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION i
INTEGRATED PLANT ASSESSMENT MLTilODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS i
t NRC Ouestion No.11 I
Explain in more detail how interviews with experienced personnel may be used for screening purposes.
Give examples where ITLR determinations may require interviews. (Page III-2) ilG&E Response Interviews with experienced personnel may be used to gather information about conceptual system boundaries and functional requirements, as described in paragraph 3.2, page III-2 of. the methodology. This information is placed in Table 1, System / Structure Information, during the initial step of the screening process. Important to license renewal determinations are not made in this step, and the interviews are not used as a basis for ITLR determinations at any point in the screening.
NRC Ouestion No.12 For each systern or structure listed in Attachment A, only the primary functional requirements are identified. Explain why secondary functions are not considered, panicularly if a secondary function supports a safety-related system, the failure of which couldprevent the properfunctioning of the safety-related system. Ifit was determined later that the primaryfunction was no longer required, is there a process that would ensure that the secondary function is then evaluated with respect to ITLR7 (Pages 111-2 andIV-9)
IIG&E Response j
During system level screening, functional requirements of the systems and structures are determined during the first step of the process, as described in paragraph 3.2, page III-2 of the methodology.
These functional:equirements are general, high-level functions of the systems and structures and no specific ITLR determination is made at this point of the process. During the Component level ITLR Screening for Systems, specific ITLR tunctions for the systems are determined during the first l
step of this process, as described in Section 4.1.1 of the methodology. These functions include secondary (vital auxiliary in BG&E nomenclature) functions, the failure of which could prevent the proper functioning of a safety-related system. Component level screening identifies all system ITLR functions as well as the system components associated with each function. A component is designated as not ITLR only if it has no ITLR function. Consequently, deletion of any ITLR i
function at some point in the future would result in redesignation (as not ITLR) of only those l
components associated exclusively with the function being deleted.
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IIALTIMORE GAS AND ELELTRIC COMPANY (llG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METIIODOLOGY SYSTEMS, STRULTURES AND COMPONENTS To avoid the confusion associated with the term " primary function" and " functional requirements,"
several editorial changes will be made to the methodology. These changes are all described in the BG&E response to Question 35.
NRC Ouestion No.13 IVhere is the summary tablefor systems and simctures ITLR that is mentioned in the thirdparagraph of Section 3.2? (Page111-2)
HG&E Resp (mse The summary table for systems and structures ITLR mentioned in the third paragraph of Section 3.2, page III-2, of the methodology is Table 1, System / Structure Information. The table is contained in Attachment C of the methodology. The methodology will be revised to refer to this table by title in Section 3.2.
The reworded paragraph is:
The following information is compiled for each system and structure and entered into a table designated as " Table 1 System / Structure Information."..
NRC Ouestion No.14 Figure 2-1 indicates that to satisfy Rule Critenon 2 (all non-safety-related SSCs who's failure could directlyprevent satisfactory accomplishment of any of the requiredfunction.
.), a vital auxiliary tool will be prepared. Section 3.3.1.1 mentions that in preparing the DBEJlowcharts, supponing systems and vital auxiliaries will be identified. Ilow does the methodology and the vital auxiliary screening tool (Attachment C, DBE Flowchart, Figure 14-50) assure that all supponing systems are identified?
(Pages 11-17,111-4,111-5 and 111-6) j IIG&E Resp (mse As described in paragraph 3.3.1.1, page III-5 in the methodology, the O-List Accident Row Sheets identify the vital auxiliaries for the systems performing the safety functions. The O-List Vital Auxiliaries How Sheet is a compilation of the systems performing the vital auxiliary functions. The DBE Howchart, Figure 14-50, is derived from the 0-List Vital Auxiliary How Sheet and lists all the systems contained thereon. The 0-List Vital Auxiliaries How Sheet was prepared by reviewing all plant equipment which directly responds to mitigate consequences of DBEs. During this review, SSCs were identified which provide all supporting services, such as instrument air needed for valve 10
4 HALTIMORE GAS AND ELECTRIC COMPANY (llG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION i
INTEGRATED PLANT ASSESSMENT METIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS operations, electrical power required for valve, pump and motor operation or parameter indication, and cooling air and water to prevent damage of equipment. The compilation of these supporting SSCs for all DBEs constitutes the Q-List Vital Auxiliaries Flow Sheet (Q-List Manual Attachment F, Section 6.2).
To clarify this point in the methodology, the fifth paragraph of Section 3.3.1.1 will be modified as shown below.
The Q-List Manual also contains a specific flow chart for vital auxiliaries. Electric power distribution; control air; cooling water and heating, ventilation and air conditioning functions were reviewed for the safety-related equipment required to respond to each DBE. These vital auxiliaries were annotated in the corresponding Q-List Accident Flow Sheet.
Therefore, the Q-List Accident Flow Sheets identify all the vital auxiliaries for the systems performing safety-related functions. The Q-List Vital Auxiliaries Flow Sheet is a compilation of the systems performing the vital auxiliary functions for all Q-List Accident Flow Sheets.
The Vital Auxiliaries Screening Tool (referred to as DBE Flow Sheet 50 in the Systems / Structures ITLR Screening Results) contains all SSCs listed on the Q-List Vital Auxiliaries Flow Sheet.
NRC Ouestion No.15 How does the methodology record the design basis events for which a design basis event powchart is NOTprepared? Isn't it necessary to prepare a powchart in order to identify the systems used and then compare the systems used against other eventpowchans to determine that allsystems have already been identified. How did theprocess assure thatfor those events withoutflowchans thefunctionsperformed by identified systems were identical? (Page HI-5) i HG&E Response For the eight DBEs lacking an accident flow sheet in the Q-List Manual, a DBE Flow Sheet is prepared by the ITLR screening process and is included in the System / Structure ITLR Screening Results. The Q-List Manual gwes the reasons an accident flow sheet was not prepared for each of these eight DBEs. These reasons can be summarized as follows:
Plant equipment required to respond to the DBE is completely included within the equipment required to respond to another DBE and an Accident Flow Chart has been prepared for the other DBE.
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BALTIMORE GAS 'AND ELECTRIC COMPANY (BG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION LNTEGRATED PLANT ASSESSMENT MLTIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS P
OR No active components are credited for mitigation of the DBE.
Design Basis Event Flow Sheets in the Systems / Structures ITLR Screening Results for these eight DBEs contain the following information:
Passive components relied upon to mitigate the consequences of the event OR A note indicating that no active or passive components are relied upon for the event OR A note indicating that the equipment relied upon for the DBE is completely included in another DBE. In this case, the DBE Flow Sheet will note which other DBE subsumes the given DBE. This determination is based upon the descriptions of the DBEs in the UFSAR Chapter 14 and the discussions contained in the Q-List Manual pertaining to the events.
C In order to clarify the description of these DBE Flow Sheets in the methodology, paragraphs 3 and 4 of Section 3.3.1.1 will be replaced with the following:
P For the eight DBEs which are identified in the UFSAR and are not the subject of Accident Shutdown Flow Sheets in the Q-List Manual, a DBE Flow Sheet is prepared by the systems and structures ITLR screening process. These DBE Flow Sheets contain the following information depending on the reasm that no Q-List Accider* Flow Sheet was prepared (as i
documented in the Q-List Manual).
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BALTIMORE GAS AND ELECTRIC COMPANY (IIG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METIIODOLOGY SVSTEMS, STRUCTURES AND COMPONENTS I
Reason Why No 0-List Accident Flow Content of Screening Results DBE Flow Sheet Sheet No active components are relied upon Passive components which mitigate the to mitigate the event.
DBE. -
No active or passive components are A note stating that no active or passive required to mitigate the event.
components are required to mitigate the event.
All components relied upon for the A note stating that all components event are already included in another required to mitigate the event are included Accident Flow Sheet.
in another DBE Flow Sheet and specifying which other DBE(s).
The DBE flow charts for the remaining 17 DBEs identify the systems, and the functions provided by each of thuc systems, in order to support the Critical Safety Functions necessary to reach safe shutdown for the specific DBE, maintain the fission product barriers and prevent offsite releases in excess of established guidelines.
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-.eJ IIALTIMORE GAS AND ELECTRIC COMPANY (BG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS NRC Ouestion No.16 The report states that a specific chanfor vitalatailiaries isprepared and Figure 2-1 shows a specific tool for vital atailiaries, however, preparation of the vital auxiliaryflowchart is not fully discussed. Please explain the methodologforpreparing the vital auxiliaryflowchart in Attachment C, DBE Flowcharts, Figure 14-50. (Pages11-17,11-5and111-6)
HG&E Response See the answer to Question 14.
NRC Ouestion No.17 The methodolog states that in order to be identified as a system or simcture important to license renewal, a system or stmeture must be " credited in the analys 's or evaluation." What specific criteria was used to make the detennination that a system or simcture was " credited" in an evaluation or analysis?
Pleaseprovide examples ofhow thisprocess was implemented. (Page111-6)
HG&E Resp <mse The term " credited in the analysis" was used in the methodology to distinguish between structures and components mentioned in the event analysis which were called upon to operate to mitigate the
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consequences of the event versus structures and components which were assumed to operate m
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order to make the event more severe.
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l Hree examples are provided below to demonstrate this point.
i EXAMPLE 1 - In the less of Feedwater Flow Event, the turbine bypass valve is assumed to open because this operation creates the " worst case scenario" for the event. ("The analysis assumes that the turbine bypass valves are operable as it increases the steam generator flow and depletes the j
steam generator liquid more rapidly" [UFSAR ' ection 14.6.2]) In this example, the turbine bypass valve is not " credited" with operating to mitigate the consequences of the event, and therefore would not be designated as safety-related in the CCNPP Q-List Manual. Consequently, it would not be screened as ITLR for Criterion 1.
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EXAMPLE 2 -In a similar manner,in the waste evaporator, the evaporators are assumed to rupture to cause the event. The analysis concludes that the failure would cause no offsite dose in excess of 10 CFR Part 100 guidelines. In this event, the waste evaporators are not " credited" with mitigating the consequences of the event and are therefore not screened as ITLR due to Criterion 1.
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J HALTIMORE GAS AND ELECTRIC COMPANY (IIG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS EXAMPLE 3 - In the Steam Generator Tube Rupture Event, various instrumentation is assumed to operate. Some instrumentation produces a signal which starts equipment. For example, the low pressurizer level signal initiates a safety injection actuation signal which starts the high pressure and low pressure safety injection pumps. The instrumentation associated with these signals is credited in the analysis and is screened as ITLR per Criterion 1. Some instrumentation produces a signal which initiates operator action. For example, Ihe radiation monitoring system is relied upon to indicate that a steam generator tube rupture has occurred. The analysis in the UFSAR assumes that the operator isolates the affected steam generator 30 minutes after the event. Based on this reliance on indication, the radiation monitoring system is screened as ITLR for Criterion 1. Conversely, the operator is assumed to trip the reactor coolant pumps because this action is required after a safety injection actuation signal caused by a low pressurizer pressure indication. The reactor coolant pump coast down results in increased hot leg temperatures, slower depressurization rate and increased time for pressure to decrease below high pressure safety injection pump shutoff head, thus conservatively providing the conditions for the worst case event. The pressurizer low pressure indication in the Control Room is not credited in this event since the operator action this indication initiates aggravates the event. Therefore, the circuitry associated with this indication is not screened as ITLR for Criterion 1 based on its role in this DBE.
The UFSAR Chapter 14 analyses make it quite clear which equipment functions to mitigate the consequences of the event and which functions or fails in order to cause or exacerbate the event.
The former were screened as ITLR due to Criterion 1, while the latter were not.
NRC Ouestion No.18 The report states that in developing the screening tools, Jimctions that are " identical to safety-related functions (as identified in the Q-List)" need not be repeated in the screening tools for Rule Criterion 3 (i.e., FP, EQ, SBO, etc...). Please explain. (Page 111-6 & 7)
IIG&E Response The purpose of our system level screening is to identify all ITLR functions for ITLR systems. If a system performs a specific function in one or more DBEs, then identifying and documenting the identical function for that system for Rule Criterion 3 is redundant. For example, if a system must provide cooling water to a component to bring the plant to a safe shutdown for a variety of DBEs, then no new information is gained by recording that the system must also provide cooling water to bring the plant to a safe shutdown in the case of a severe fire in compliance with 10 CFR 50.48.
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BALTIMORE GAS AND ELECTRIC COMPANY (BG&E) j RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION i
INTEGRATED PIANT ASSESSMENT MLTIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS NHC Ouestion No.19 I
Please clarify what is intended to be screened for ITLR in the discussion ofpressuri:ed thennal shock l
(PTS). How did CCNPP identify the SSCs, other than the reactor vessel, in their CLB that are required to comply with the PTS rule? (Page III-8; Attachment B, page 22; and Attachment C, PTS Screening j
Tool) l f
HG&E Resmmse It is our understanding that this ITLR criterion is not intended to screen in any new SSCs if a plant does not exceed the PTS screening criteria described in 10 CFR 50.61. If this PE screening criteria is exceeded and a plant relies on an evaluation performed in accordance with Regulatory Guide 1.154, certain SSCs may be relied upon in the 1.154 evaluation to function to prevent or i
mitigate a PTS event. In this circumstance, the SSCs relied upon in the Regulatory Guide 1.154 analysis would be screened as ITLR for PTS.
Consequently, the following changes will be made to the methodology:
i 1.
Source document 25 will be deleted from Table 2-1.
2.
Section 3.3.2.3 will be replaced with the following:
Since neither CCNPP Unit 1 nor 2 is expected to require an evaluation in accordance with Regulatory Guide 1.154 in order to satisfy 10 CFR 50.61 requirements, no equipment is screened as ITLR due to the PTS Rule. The PTS Screening Tool is provided in the Systems / Structures ITLR Screening Results but this tool merely notes that no SSCs are relied upon for this event. Additionally, the ITLR System Level Screening Results, the component level screening process and the component level screening results for each system include the contingency to implement a PTS screening criterion but the results indicate no PTS-related l
SSCs. If a Regulatory Guide 1.154 evaluation is required at some point in the future, the ITLR screening process would be modified to require incorporating the PTS functions relied upon in the 1.154 analysis into the PTS Screening Tool. The Regulatory Guide 1.154 analysis would also trigger an update to the system level and component level screening results to screen the SSCs associated with the 1.154 functions.
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l HALTIh10RE GAS AND ELECTRIC COh1PANY (IlG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORh1ATION INTEGRATED PLANT ASSESSh1ENT AIETIIODOLOGY SYSTEh1S, STRUCTURES AND COh1PONENTS 3.
Appendix C, Systems / Structures Screening Results, PTS Screening Tool, will be modified to include only a note to explain that no ITLR functions associated only with PTS were i
identified during the screening process.
r 4.
Appendix C, Systems / Structures Screening Results, Table 2 ITLR System Level Screening Results, will be changed to indicate a "NO" in the PTS column for all systems.
NRC Ouestion No. 20 i
Equipment necessary for restoration of power after the event falls within the scope of the station blackout (SBO) rule, therefore, system or stnictures requiredfor restoration ofpower should be within the scope of the license renewal nile. Please revise the methodology to reflect this. (Pages III-8 andIV-8)
IIG&E Resmmse The equipment needed to restore power during an SBO event consists of either onsite or offsite The onsite sources consist of the safety-related emergency diesel generators. These sources.
components are already screened as ITLR under ITLR Criterion 1 and 2 since they mitigr.::: DBEs and serve as vital auxiliaries to safety-related equipment.
Selected offsite power sources which could be used to restore power during an SBO event are already screened as ITLR under ITLR Criterion 4 since they have a Technical Specification Limiting Condition for Operation (LCO) and satisfy the additional Technical Specification criteria contained in the methodology, Consequently, there is no need to consider the power restoration phase of SBO separately since several success paths for restoring power after an SBO are already screened for other ITLR criteria.
The methodology will be modified as shown below.
i 1.
Section 3.3.2.5 will be replaced with the following:
The SBO Analysis [24] is resiewed to identify systems and structures which are relied upon during the " coping duration" phase of an SBO event. An SBO Screening Tool is prepared which lists the systems and structures relied upon in the SBO Analysis, the function (s) that 17
J HALTIMORE GAS AND ELECTRIC COMPANY (IIG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS cach system and component provides, and the appropriate source documents with revision numbers. The power restoration phase of the SBO analysis is specifically excluded from review in this criterion since several success paths for restoring power after an SBO are already screened as ITLR due to Criterion 1 (safety-related) or Criterion 4 (Technical Specifications LCOs).
2.
The second bullet of the eighth paragraph of Section 4.1.3 will be modified as follows:
Much of the equipment mentioned in the SBO Evaluation is mentioned because it is secured at the start of an SBO event or is used when restoring power after the end of the event.
These components will not contribute to any SBO functions in the SBO Tool and, therefore, should not be screened as ITLR. These components are not included in the SBO function catalogs.
NRC Ouestion No. 21 The current screening process for identifying systems, structures, or components that are covered by operability requirements in the technical specifications is not consistent with the license renewal nde.
The use of criteria such as the screening critena from the technical specification improvementprogram to eliminate systems, sinactures, or components is not pennitted by 10 CFR Part 54. The Statement of Considerations to the nde clearly discussed the extent of the systems and stmetures to be identifled. The limiting condition for operation (LCO) screening tool must be modified to make it consistent with Part 54. Note: The use of this tool as presently wdtten could be acceptable if pdor to or during application for a license renewal, BG&E submitted a request to revise their current technical specifications to adopt those established under the genenc technicalspecification improvementprogram and it was approved by the NRC. (Page 1119)
BG&E Response As discussed in the response to Question 5, the Technical Specification LCO Screening Tool will be reviewed again prior to License Renewal Application submittal. This review will ensure that the tool
[
includes all ITLR functions associated with LCO operability requirements in the version of the Technical Specifications in effect at that time.
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J HALTIMORE GAS AND ELECTRIC COMPANY (IIG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS NRC Ouestion No. 22 Section 3.3.2 allows LCO functions that are identical to safety-related functions to be excluded from consideration. Ilowever, in Section 3.4, it is recommended that allITLRfunctions be listed tofacilitate component level screening. Please explain why in one section the methodology report discourages redundancy in functions and in the next section recommends listing allfunctions. (Pages 111-10 & 11)
IIG&E Resmmse As explained in the response to Question 18, redundant identification of ITLR system functions is avoided in preparing the tools. All ITLR functions are listed once. Important to license renewal functions are not repeated in a subsequent tool if they serve more than one ITLR criterion.
For example, if a certain system must provide cooling water to safety-related equipment to mitigate the consequences of a design basis event, that ITLR function will be captured by the vital auxiliaries flow chart. No new information would be gained by documenting in the LCO Tool that the system must provide cooling water to the same components because a Technical Specification LCO applies to the system.
Section 3.3.2 prevents the redundant listing of functions, while Section 3.4 ensures that the list of functions is complete. These two objectives are not contradictory as is implied by the question.
NRC Ouestion No. 23 The methodology discusses how the pressure boundary (PB) functions catalog is prepared, however the discussion makes no mention of using this as an input to the screeningprocess. How is the PBfunction catalog used in screeningfor components ITLR? (Page IV-7)
IIG&E Resmmse As described in Section 4.1.1, pressure boundary (PB) components are determined to be ITLR because they support either Criterion 1 or Criterion 2 of the ITLR definition. Criterion 1 PB components serve as fission product boundaries. Examples of Criterion 1 PB components are the Reactor Coolant System piping and valves and the containment isolation piping and valves.
Criterion 2 PB components include those PB components whose failure could cause another safety-related component not to perform its intended safety function. Examples include service water piping and valves, because failure of these components would render the safety-related service water pumps incapabic of supplying cooling water to required loads, i
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.i HALTIMORE GAS AND ELECTRIC COMPANY (liG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METHODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS The PB function catalog contains those components for a system which were determined to be ITLR for PB. The PB function catalog does not distinguish whether the components are ITLR for Criterion I or Criterion 2. The PB function catalog and all other ITLR function catalogs contain the results of the component screening process, sorted by function. When these results are resorted by component, they constitute the component level ITLR screening results. See Section 4.I.4 for more discussion of how function catalogs are transformed into the screening results.
NRC Ouestion No. 24 Section 4.L3 allows safety-related Q-list (SR-0) components to be screened out as not ITLR if the reason behind the SR-Q classification does not correspond to any fimction catalog. Further, the classification of that component could be downgraded. It appears that BG&E is using this process to update and revise the G. list based on ITLR. Does this mean that a component must be ITLR to be Q-list? (PageIV-9)
IIG&E Response Given the detailed review of a significant amount of plant documentation required to perform the IPA for Aging, BG&E is using the IPA process to initiate revision of any document encountered for which revision is appropriate. There is no requirement that a component must be ITLR to be Q-List. However, when a component is found which is controlled in the Q-List but it does not mitigate the consequences of DBEs, does not support safety-related equipment,is not required for any of the five regulated events in the ITLR definition, and has no Technical Specification LCO associated with it, we believe a review is appropriate to determine whether controls under the Q-List are really needed. Whenever it is believed that such controls are not required, site processes for downgrading of components are followed to determine if the change of classification is appropriate.
IIowever, the reference to initiating the Q-List modification process is not a step which contributes to the ITLR screening process. Therefore, Section 4.L3, paragraph 10, will be modified as follows:
The equipment in the system Master Equipment List which is designated in the Q-List Manual as safety-related Category "Q" also requires further analysis during the screening process._ The documentation which supports the classification of these type components is reviewed to determine why the equipment has been designated as safety-related Category O.
If the SR-Q components perform an ITLR function, the components are included in the corresponding ITLR function catalog. Otherwise, the components are screened as not ITLR.
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l HALTIMORE GAS AND ELECTRIC COMPANY (BG&E) l RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METHODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS NRC Ouestion No. 25 Section 4.2.2 listsfunctions ofsimctures to support the ITLR criteria, one of which is to provide a flood protection barrierfor internalflooding. If hy isn't a barrier against externalflooding considered? Are any of the sintctures at CCNPP required to withstand externalfloods in order to protect safety-related SSCs? (PageIV-12)
IIG&E Response External flooding events were considered during the design process for CCNPP structures [UFSAR Section 5A.5]. It was determined that a probable maximum hurricane would cause the worst flooding conditions at the site. The resulting surge and wave action was analyzed as the basis of plant flood protection. The effects of possible wave action was studied using a hydraulic model. This clarification sentence will be added to the description of structure ITLk Function 6 in Section 4.2.2.
NRC Ouestion No. 26 The methodolog references the Containment and Class 1 sinactures Industry Technical Reports as completeness checks for the screening methodolog. Did the industry repons identify any stntctural components that the proposed methodolog did not identify, and if so, was the methodolog revised to make sure that these components would not be missed in any future uses of this methodolog?
(PageIV-14) i IlG&E Response The industry report did not identify any structural components that the proposed methodology did
[
not identify. 'ne generic structural components list (Table 2S) was based on the industry report and then expanded. Additionally, the methodology requires review of structure layout drawings and the
- addition of any components specific to the structure being evaluated to be added to Table 2S. This assures that no components are excluded from consideration.
To clarify the use ofindustry reports in this step, the first paragraph of Section 4.23 will be modified as follows:
In the structural component screening process, components that are structural in nature are not uniquely identified during the screening process. For example, each wall in the structure is not identified, named and listed. Rather than using a Master Equipment List of named structural components, the screening is conducted on a generic listing of structural component types. This generic list was developed by experts in the field of nuclear Class 1 i
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J IIALTIMORE GAS AND ELECTRIC COMPANY (IIG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION i
INTEGRATED PLANT ASSESSMENT METilODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS structures. The generic list started with structural component types contained iri the Containment Industry Technical Report and the Class I structures Industry Technical Report. Other structural component types were added to the list to ensure completeness.
(e.g., The Industry Technical Reports considered only safety-related functions. Therefore,
(
several fire and flooding-related component types were not considered in these reports.)
(
NRC Ouestion No. 27 l
The methodolog employs a ' commodity" screening step that puts cenain types of components into generic groups. The methodologfunher states that a cable is ITLR ifis supplies a safety-related load.
How does the methodolog screen cables that supply non-safety-related systems that suppon safety-related systems? The methodolog should be e.tpanded to clanfy these circumstances. (Page IV-16)
IIG&E Response The definition ofITLR governs what support equipment must be screened as ITLR. Criterion 2 in this definition states:
All non-safety-related SSCs whose failure could directly prevent satisfactory accomplishment of any of the required functions identified in (I)(i), (ii) or (iii) of this definition. (i.e., safety-related SSCs).
Based on this criterion in the ITLR definuinn, the BG&E methodology :,creens support equipment for safety-related components as ITLR and support equipment for non-safety-related components as not ITLR, even if the non-safety-related component being supported is ITLR. Consequently, the cable supporting an non-safety-related component which serves as a vital auxiliary to a safety-related component would be screened as not ITLR.
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BALTIMORE GAS AND ELECTRIC COMPANY (llG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METilODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS Responses to Request for Additional Information - Editorial NRC Ouestion No. 28 A large number of abbreviations, acronyms, etc., are used throughout the document. Consider adding a separate listing of such nomenclature and the definitions for each (in a separate section in the first chapter or in an appendix) so that the reader / reviewer can easily refer to the listing without having to go back into the text tofind where the abbreviations or acronyms werefirst explained.
IlG&E Response A list of acronyms will be provided as Table 2-2. Definitions are already included in Section 2.1.
NRC Ouestion No. 29 The bracketed information on Pages ir and IV-17 should be deleted now that the submittal has been submitted to the NRC. (Pages iv and IV-17)
BG&E Response The bracketed information on pages iv, I-4 and IV-17 will be deleted.
NHC Ouestion No. 30 When referencing or describing tables, figures, etc., be consistent with your use of terms and titles. For example, it is not clear if the 'lTLR screening summary table," mentioned on Page III-2 is Table 1,
' System / Structure Information" in Attachment C.
IlG&E Response The specific example on page III-2 will be corrected in the response to Question 13. To ensure consistency, other terms and titles will be modified in Sections 1.3,3.4,3.4.1.1,3.4.1.2,3.4.2 and 3.4.3.
NRC Ouestion No.31 The first paragraph mistakenly cites six sections to this report when there are five sections listed in the TableofContents. (Page1J)
IIG&E Response
)
The reference to six sections will be changed to five in Section 1.3.
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J IIALTIMORE GAS AND ELECTRIC COMPANY (IIG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS
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NRC Ouestion No. 32 i
in theflowchart, the diamond on the left side lists " Class I Stmetures." On Page JV-4 *CLS1"is defined.
Are these the same? Please clarify. (Pages 11-17 & IV-4) i IIG&E Resp <mse Section 4.1.1 refers to a category of equipment in the Q-List Manual abbreviated as "CLSI." This category is identical to the term " Class 1" referred to in Figure 2-1 and elsewhere in the methodology.
A note will be added to the description of 'CLS1" in Section 4.1.1 to avoid any confusion. The term "CLS1" will be replaced elsewhere in the methodology with " Class 1."
NRC Ouestion No. 33 Figures 2-1, 2-2 and 2-3 (flowchans) should be moved to Chapter 3. They only make sense afteryou have read the actualimplementation of thepmcess. (Pages11-17,18,19)
IIG&E Response Figures 2-1,2-2 and 2-3 are provided during the oveniew of the IPA process in Section 2 and are intended for use throughout the remainder of the methodology to assist the reader in understanding the process. When the figures are introduced in the Screening Methodology Oveniew Section, reference is made to both the oveniew discussions in Chapter 2 and the det -Dei discussions in Chapters 3 and 4. The figures are first referred to in Section 2; therefore, it mal,. more sense to include them as part of that section.
NRC Ouestion No.34 i
Infonnation on many of the documents listed in Table 2-1 is incomplete as to specific edition, dates, etc.
Please include the edition, revifon, or datesfor the documents listed in Table 2-1. (Page 11-20)
IlG&E Response Where appropriate, speci'ic revisions and dates will be added to the references in Table 2-1. As explained in the response to Question 7, this table contains the references used to develop the methodology. In some cases, several versions of a source document contributed to the development of the methodology. Such cases will be noted.
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BALTIMORE GAS AND ELECTRIC COMPANY (IIG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PIANT ASSESSMENT METilOOOLOGY SYSTEMS, STRUCTURES AND COMPONENTS NRC Ouestion No. 35 The differences between " critical safetyfimction" and "primaryfunction" are not explained. This is even more complicated by the use of " specific safety function" when defining the term " functional requirements " Please clarify the differences between the terms " critical safety functions" " primary function" and " specific safetyfunction" as they are used in the screening methodology. (Definition #8, Page H-3)
IIG&E Response The response to Question 12 resolves the apparent confusion over how functions are referred to.
The methodology will be changed to ensure that the term " functional requirements" is used to refer to the general, high level functions used to establish conceptual boundaries for systems and structures but not used for ITLR determinations. The term " Critical Safety Function" will be used as it is defined in Section 2.1. This term has a specific meaning in the CCNPP Q-List and in this screening methodology. The terms "ITLR functions" or " required functions" or merely " functions" (in the proper context) will be used to denote the detailed functions which are determined to be required by one of the ITLR screening criteria. Specific changes to the methodology are shown below.
1.
The third paragraph of Section 1.3 will be revised as follows:
Section 3.0, System / Structure Ixvel Screenina, describes how systems and structures are identified and how their conceptual boundaries are determined. It specifies the criteria to be used and the m-thodology to implement the criteria. Section 3.0 describes the development and use of screening tools to help determine which systems and structures are ITLR.
2.
Definition 8 in Section 2.1 will be revised as follow i
8.
Functional Requirements - The general, high-level functions which a system or structure may be called upon to perform. The functional requirements are used during the system level screening process to establish conceptual boundaries so that when a detailed function is determined to be an ITLR function, the evaluator will
)
know which system or structure to associate the detailed function with. 'Ihe term
- functional requirements" is used to distinguish these high level functions from the detailed ITLR functions contained in the screening tools and used during the component level screening process.
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i IIALTIMORE GAS AND ELECTRIC COMPANY (BG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT MLTIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS t
t 3.
The first two paragraphs of Section 2.5.2 (renumbered 2.4.2) will be revised as follows:
i l
This Task, which is described in more detail in Section 3.0, establishes conceptual boundaries
{
for the systems and structures listed in Attachment A, develops screening tools, which capture the ITLR screening criteria, and applies the tools to the systems and structures listed in Attachment A to identify those that are ITLR. Figre 2-1 shows the logic of this Task.
Functional requirements and system descriptions for the systems and structures listed in Attachment A are identified in Subsection 3.2.
The system description and functional requirements for a system or structure are used to establish the conceptual boundary. Next, screening tools are developed to facilitate the screening process and insure consistency in screening results. To develop a tool, the evaluator reviews selected source documents as discussed in Subsection 3.3 and extracts screening-related information for all systems and structures from those documents. As a result, the evaluator avoids having to review the same source documents each time a new system or structure is screened.
4.
The third paragraph of Section 3.0 will be modified as follows:
Systems Level ITLR screening consists of several activities. Subsection 3.1 describes how systems and structures are identified and listed. Subsection 3.2 describes the development of conceptual boundaries for systems and structures. Subsection 3.3 describes the development of system screening tools. Subsection 3.4 describes how all ITLR systems and structures are i-identified. Subsection 3.5 describes how the screening results are documented.
5.
The second and third paragraph of Section 3.2 will be changed as follows:
For each of the systems and structures listed in Attachment A, the source documents mentioned above are reviewed. The functional requirements (see Definition 8. Section 2.1) are identified and a brief system description is provided. The description includes a listing of the major components and major system interfaces for each system and structure. The functional requirements list should only include the general, high-level functions that a system or structure may be called upon to perform. The description and functional i
requirements sene to establish conceptual boundaries needed for the systems level ITLR 26 i
e IIALTIMORE GAS AND ELECTRIC COMPANY (IIG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION i
INTEGRATED PLANT ASSESSMENT METIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS screening process. In the tool development step of the screening process, wheneve. a detailed ITLR function is identified, the information in Table 1 allows the evaluator to determine which system or structure the detailed function should be associated with. It is i
recognized that the list of functional requirements does not represent a detailed functions list, but this level of detail is sufficient for the purpose described above. The component level screening task develops a detailed system and structure ITLR functions list.
The following information is compiled for each system and structure and entered into a table designated as " Table 1, System / Structure Information."..
System or Structure name Unit number, l
ID number, Brief description, including major components and system interfaces, i
Source document reference (for the description) including revision, System or Structure functional requirement (s),
Source document reference (for each functional requirement) including revision.
6.
The second paragraph of Section 33.1.1 will be changed as follows:
l The CCNPP Q-List Manual [6] presents Accident Shutdown Flow Sheets for 17 of the DBEs. Each Accident Shutdown Flow Sheet identifies the Critical Safety Functions (CSFs) and plant functions supporting CSFs which are necessary to reach safe shutdown for the DBE identified, maintain fission product boundaries and prevent offsite releases in excess of established guidelines. These flow sheets also identify the supporting systems (as well as vital auxiliary systems) which are required to satisfy the associated CSF. Design Basis Event Flow Charts are a consolidation of Q-List Accident Shutdown Flow Sheets and any additional supporting systems identified as relied upon for that accident in UFSAR Chapter 14.
7.
The second sentence of Section 33.2.5 will be modified as shown below:
1
)
i An SBO Screening Tool is prepared which lists the system and structure relied upon in the SBO Analysis, the function (s) that each system and structure provides, and the appropriate source documents with revision numbers.
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1 BALTIMORE GAS AND ELECTRIC COMPANY (BG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION l
INTEGRATED PLANT ASSESSMENT METIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS 8.
The second sentence of Section 3.4 will be modified as follows:
For the DBE Tools and the Vital Auxiliary Tools, the function (s) being provided are noted on the ITLR System Level Screening Results Table.
9.
The parenthetical sentence in the description of "PB" in Section 4.1.1 will be changed as follows:
(Criterion 2 because PB includes the components needed to maintain the PB of fluid systems, even when such components do not directly contribute to the other active ITLR functions of the system.)
NRC Ouestion No. 36 The license renewal rule refers to the "requiredfunction" when determining whetherfunctions of systems or components are affected. Erplain how the definitions discussed in Question 13 adequately implementthespecificndelanguage. (Page11-3)
HG&E Response
[The assumption is made that the " Question 13" referred to in this question is actually Question 35.]
As discussed in the response to Question 35, " required function" as it is used in some places in Part P
54, is equivalent to *ITLR function" or " required function" in the BG&E methodology.
NRC Ouestion No. 37 In Definition #6, design life is the "inaximum period of operationsfor a nuclearpowerplant based on a presumed operating history." H7dch components limit the design life? What is the " presumed operating history"forCCNPP? (Page11-3)
HG&E Response The definition of " Design Life" is not germane to this methodology and will be deleted from Section 2.1.
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e IIALTIMORE GAS AND ELECTRIC COMPANY (BG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS NitC Ouestion No. 38 l
Please explain the d(ference between "CLB,"CLBID," and *CCNPPdocketed correspondence". (Pages 111-7 and 8)
IIG&E Response The terms CLB/D and CCNPP docketed correspondence and their relationship to the term CLB is explained in the response to Question 4.
NRC Ouestion No. 39 The first sentence in Section 3.4.1.1 would be better read "..DBE or whose failure would directly prevent performance of the CSFs." Please revise. (Page 111-11)
BG&E Response Comment will be incorporated.
NRC Ouestion No. 40 i
The screening toolfor simctures mentions that a review of the G-List will be performed to identify all structures orponions ofstmetures that are safety-related, Class 1. Then it states that Class 1 simctures are important to license renewal. Is the population of simctures imponant to license renewal to include BOTH safety-related Class 1 and non-safety-related Class 1 structures? If not provide an explanation for your position. In either case, clarify yourposition in the methodology report to be more precise concerningyourintent. (Page111-12) llG&E Response All Class 1 structures are safety-related at CCNPP. Section 3.4.1.2 will be modified to clarify this as follows:
i For all listed structures, the UFSAR Section 5 and the Q-List General Items section are resiewed to determine whether the structure or a portion thereof is designated as safety-related, Class 1. At CCNPP, all Class 1 structures are designated as safety-related; therefore all Class 1 structures are screened as ITLR. The results of this screening step are incorporated, along with the appropriate source document references and revision numbers or dates, into the IT' R System Level Screening Results Table for each of the structures.
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IIALTIMORE GAS AND ELECTRIC COMPANY (IlG&E)
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION INTEGRATED PLANT ASSESSMENT METIIODOLOGY SYSTEMS, STRUCTURES AND COMPONENTS NRC Ouestion No. 41 The methodolog contains references to both source documents and to reference documents. While there is a list of source documents provided, there doesn't seem to be a reference list contained in the methodolog. Provide the list ofreference documents used in developing the methodolog. (Page IV-5)
ILG&E Rest >onse The list of documents used as developmental references for the methodology is included in Table 2-1.
NRC Ouestion No. 42 In discussing the implementation of the methodologforfooding, the methodolog refers to "func' ions 5 and 6." At this point in the methodolog report it is not clear which specific functions are referenced.
Restate the specificfunctions that are referenced by this paragraph. (Page IV-15)
IIG&E Response To avoid any confusion, the methodology Section 4.2.4 will be modified as follows:
The O-List Manual and Flooding Design Guidelines Manual are reviewed to determine if structural component types in the structure being screened are relied on in these documents to contribute to the functions of providing structural and/or functional support to non-safety-related equipment, whose failure could directly prevent satisfactory accomplishment of any of the required safety-related functions or providing flood protection barriers. If structural component types in the structure being screened are determined to contribute to these functions, then this information is captured by recording "YES" in the " Applicable to This Structure?" column of Table 1S (Structural ITLR Functions Table). The components that contribute to these functions are then recorded on the Table 3S with a reference to the appropriate ITLR structure function.
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