ML19350B781: Difference between revisions
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
StriderTol (talk | contribs) (StriderTol Bot change) |
||
Line 290: | Line 290: | ||
The purpose of this task was to test if, from an engineering and operations standpoint, a DSS concept is feasible. At this early stage BECo did not intend to firTn up a conceptual design upon which details could be addec later but, rather, test if component and interface requirements of a DSS design (one out | The purpose of this task was to test if, from an engineering and operations standpoint, a DSS concept is feasible. At this early stage BECo did not intend to firTn up a conceptual design upon which details could be addec later but, rather, test if component and interface requirements of a DSS design (one out | ||
A-22 of many possible designs) result in a manageable concept which could be pur-sued further. A conceptual description of a DSS was formulated using the | A-22 of many possible designs) result in a manageable concept which could be pur-sued further. A conceptual description of a DSS was formulated using the base line criteria provided by Section IIIL of Appendix R , selecting decay heat removal capability at one hour after shutdown, and vaunding the , | ||
base line criteria provided by Section IIIL of Appendix R , selecting decay heat removal capability at one hour after shutdown, and vaunding the , | |||
upper limit of system flow rate using NUREG-0460, Alternate 4 order of magni tude boration rate. This level of detail of criteria was believed to be commensurate with the level of detail required for the preliminary investi-gation. A rough order-of-magnitude estimate of the size of components, cost and time required for installation of such a system was arrived at. | upper limit of system flow rate using NUREG-0460, Alternate 4 order of magni tude boration rate. This level of detail of criteria was believed to be commensurate with the level of detail required for the preliminary investi-gation. A rough order-of-magnitude estimate of the size of components, cost and time required for installation of such a system was arrived at. | ||
The concept was then reviewed by BEco personnel of various disciplines (Nuclear Operations, Engineering and Operations Support). Comments received were incorporated into the concept. | The concept was then reviewed by BEco personnel of various disciplines (Nuclear Operations, Engineering and Operations Support). Comments received were incorporated into the concept. | ||
Line 319: | Line 317: | ||
-Task Status: Expected Start: August 5, 1981 Expected Completion: October 15, 1981 | -Task Status: Expected Start: August 5, 1981 Expected Completion: October 15, 1981 | ||
ATTACHfiENT B B REQUEST FOR EXEMPTION | ATTACHfiENT B B REQUEST FOR EXEMPTION | ||
: 1. EXEMPTIONS TO REQUIREMENTS OF SECTION III(G)(2) PERTAINING TO DIFFERENT AREAS AT PILGRIM STATION UNIT #1 A. The Cable Spreading Room Boston Edison Company petitions the Comission for an exemption from requirement for its Cable Spreading Room based on its assertion that the installed alternative shutdown system per SER requirements satisfy the intent of Section II"(G) in that an orderly shutdown can be achieved effectively after a fire is detected in the CSR. Boston Edison had com-pleted the implementation of this Alternative Shutdown System in response to the requirement in the Safety Evaluation Report. Boston Edison has spent appruximately $750,000 to this effort. | : 1. EXEMPTIONS TO REQUIREMENTS OF SECTION III(G)(2) PERTAINING TO DIFFERENT AREAS AT PILGRIM STATION UNIT #1 A. The Cable Spreading Room Boston Edison Company petitions the Comission for an exemption from requirement for its Cable Spreading Room based on its assertion that the installed alternative shutdown system per SER requirements satisfy the intent of Section II"(G) in that an orderly shutdown can be achieved effectively after a fire is detected in the CSR. Boston Edison had com-pleted the implementation of this Alternative Shutdown System in response to the requirement in the Safety Evaluation Report. Boston Edison has spent appruximately $750,000 to this effort. |
Latest revision as of 04:10, 18 February 2020
ML19350B781 | |
Person / Time | |
---|---|
Site: | Pilgrim |
Issue date: | 03/18/1981 |
From: | Morisi A BOSTON EDISON CO. |
To: | Eisenhut D Office of Nuclear Reactor Regulation |
References | |
81-59, NUDOCS 8103230687 | |
Download: ML19350B781 (38) | |
Text
I fN /
- .~ '%
2 's y BO sTO N EDISON COMPANY g e asus..s arrice. aco sovt.vou sr.asr ,*g 2, r--
....~......u...o2.. , o g
'" " ' A
^VA NUCLEAR o PERATICNS SUPPORT oEPARTM ENT March 18, . N BECo. Ltr. #81-59 Mr. Darrell G. Eisenhut, Director Division of Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D. C. 20555 License No. DPR-35 Docket No. 50-293
Subject:
Status of Boston Edison Effort In Meeting the Schedular Requirements of Appendix R to 10 CFR Part 50 References : (a) License !40. DPR-35 (Docket No. 50-293)
(b) Boston Edison Company Letter #81-52 dated March 9,1981.
(c) U.S. NRC Letter to Boston Edison Company dated February 20, 1981.
(d) U.S. NRC Letter to Boston Edison Company dated Noventer 24, 1980.
(e) 10 CFR Section 50.48 and Appendix R (f) Motion for Partial Stay Filed by Boston Edison Company, NUSCo, FP&L and AP&L with the NRC on January 16, 1981.
Dear fir. Eisenhut:
On March 9,1981 Boston Edison Company submitted a request for an exemption from implementation schedule as stated in Section 50.48 of Appendix R (Reference (b)).
This request was necessitated due to the inherent complexity in evaluating certain requirements in Appendix R within the time frame allotted for them in the rule.
We explained in detail our action plan to meet the intent-of some of the specific requirements and identified the need to have the filing date of March 19, 1981 extended to October 31, 1981. Boston Edison is not presently in a position to submit plans and schedules for meeting the provisions of Paragraphs (c)(2), (c)(3) and (c)(4) by March 19. Therefore, we submit a status of all our engineering efforts as of March 13 with the best engineering estimate for their completion.
This information is provided in Attachment (A) to this letter.
M[
5 In Reference (b) Boston Edison has also stated that it would submit specific sub- f stantive exemption requests pertaining to the requirements of the rule itself as they are stated and as they are applied to specific areas. These exemptions are authorized by 10 CFR 50.48 (c)(6), will not endanger life or property and, for the reasons we have given, are fully justified in the public interest. Refer to Attachment (B) for the details of these specific exemption requests.
230&Q
CO71 TON E2 ICON COMPANY Mr. Darrell G. Eisenhut, Director March 18,1981 Page 2 The technical justifications for these exemption requests are based on Boston Edison's analyses and evaluations perfomed to date in response to Appendix R as well as the Safe Shutdown Analysis performed in response to requirements in the SER. Boston Edison believes that such exemptions are justified on the ground that the fire protection measures prescribed in Section III(G) would not, if in-stalled at Pilgrim, " provide substantial, additional orotection which is required for the public health and safety or the common defense and security" within the meaning of 10 CFR 50.109(a). Furthermore Boston Edison does not believe comoli-ance with Section III(G)(2) at this time, prior to completion of oncoing analyses is required to provide adequate fire protection capability at Pilorim Nuclear Power Station.
In conclusion, we wish to emphasize that Boston Edison has committed and will commit in future significant financial as well as human resources to meet all of its fire protection obligations in accordance with a rational, achievable schedule of priorities. We submit that this conmitment is fully consistant with our and NRC's obligation to assure that the public health and safety are maintained at all times.
Should further information be required, please contact us.
Very truly yours,
[jz n:'MW Attachments:
( A) Appendix R - Requirements IIIG/IIIL Status Report (B) Request for Exemption cc: Messrs. Joesph M. Hendrie John F. Ahearne Victor Gilinsky Samuel J. Chilk Harold R. Denton Thomas A. Ippolito
. ]
~
ATTACHNENT A A-1
- j APPENDIX R - REQUIREMENTS IIIG/IIIL STATUS REPORT I. General Section III.G of Appendix R entitled " Fire Protection of Safe Shutdown Capability" requires that fire protection be provided so that one train of systems necessary to achieve and maintain hot' shutdown condition is free of fire damage. Further, it requires that systems necessary to achieve and maintain cold shutdown be capable of being repaired within seventy two (72) hours.
Five alternatives were prescribed in the requirement as means to achieve these objectives:
- 1. 3-hour fire barrier separation between redundant systems
- 2. Spatial separation of 20 feet or more between redundant systems coupled with smoke detection and automatic suppression systems
- 3. 1-hour fire barrier separation between redundant systems coupled with smoke detection and automatic suppression systems.
- 4. Alternative Shutdown methods (re-routing, re-locating, or modifying existing systems). ,
- 5. Dedicated Shutdown System.
Subsequent to the issuance of Appendix R, Boston Edison Company has fomulated a plan and initiated several engineering activities intended to accomplish the following:
A. Determine the extent to which previously completed and approved fire protection and other modifications mee't the requirements of Section III.G.
B. Develop Technical justifications to support requests for . exemptions from Section III.G in areas where it will be warranted.
C. Determine if any modifications will be necessary to achieve compliance with Section III.G D. Perform evaluations of each of the prescribed alternatives with respect to the
A-2 plant's condition and arrive at the most appropriate set of modifications (if found necessary).
E. Develop plans and schedules for any modifications found necessary to satisfy requirement III.G.2 E. Develop design descriptions for alternative or Dedicated-Shutdown System if found necessary to satisfy requirement III.G.3.
II. ENGINEERING ACTIVITIES Four major engineering activites were initiated and are currently in progress:
- 1. Safe Shutdown Analysis.
- 2. Alternative Shutdown Capabilities Evaluation.
- 3. Fire Barrier Evaluation.
4 Dedicated Shutdown System Study.
The following section describes each activity, provides information on the tasks com-prising the activity,their status and their time duration.
Attachment 1 (Boston Edison document no. SKE-76560-170 " Appendix R IIIG/IIIL Task Flow Chart") provides a flow network and illustrates the interdependence of the tasks and their time constraints. The task numbers identified for each activity correspond to the task numbers in the diagram.
A-3 1.0 SAFE SHUTDOWN ANALYSIS 1.1 General The engineering efforts throughout the numerous tasks associated with the Safe Snutdown Analysis are intended to yield two basic results:
- 1. ven a fire zone at the station, detennine whether the capability exists to achieve a safe plant shutdown in the event of fire in the zone.
- 2. If the capability to achieve a safe plant shutdown in the event of fire in the fire zone' does not exist - identify the equipment and/or circuits in the zone that require fire protection as prescribed by the requirements of Section III G.2 of Appendix R.or modification as prescribed by Sections III.G.3 and IIIL.
This infomation will be utilized, in turn, as an input to the other major activities in order to generate an overall assessment as to the feasibility of each prescribed fire protection option and arrive at an optimal fire protection of the safe plant shutdown capability.
In the process of fonnulating the plans for this major activity, certain assump-tions had to be made as to the definition of Fire Zones, Associated Circuits, the fire event and the systems requirements:
A) In conducting the analysis a fire area may be sub-divided into one or more fire zones for purposes of hazard identification. (A fire zone is considered to be the zone of influence of the maximum credible fire). Based upon this evaluation, any required protection will be designed to protect against the hazards in the zone.
B) Associated circ its were defined a.s those Non-Safety Related circuits either electrically connected to Safety Related circuits, or share the same raceway or enclosure with Safety Related circuits (regardless of the degree of spatial separation).
C) Assumptions about the fire event:
- 1. Loss of offsite power occurs concurrently with the fire. Offsite power supply is established at the end of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
A-4
- 2. The reactor is scramed from 100", power via automatic initiation due i to loss of Offsite Power or prompt manual initiation upon detection of a serious fire.
- 3. Design Basis Accidents do not occur coincident with a fire.
- 4. Abnomal transients do not occur concurrent with a fire.
- 5. Single fa,ilure other than direct or consequential failures resulting from the fire do not occur concurrent with a fire.
- 6. Manual Operator action is relied upon when possible.
D. Assumptions on equipment design and function:
- 1. Proper power circuit-breaker coordination exists at all voltage levels.
- 2. Proper fuse-to-breaker coordination exists in all cases where fuses are used.
- 3. Fuse-to-fuse coordination is not relied upon.
4 Components are properly rated.
S. tio mectianical failures of raceways occur.
It should be sloted that the above assumptions constitutes the basis of the analysis..
~
Recent infomation t: ..ed to us through the February 20, 1981 letter to all power reactor licensees with plants licensed to operate prior to January 1,1979 from D. G. Eisenhut Director Division of Licensing, Office of fluclear Regulation, NRC, will be reviewed to detemine its effect on our assumptions and, thus, on the analysis procedure. No attempt has been made in this report to evaluate the effect of the flRC Staff's concerns regarding the Safe Shutdown capability on the expected time schedule for completion of the analysis.
1.1 Task Descriptions Task 1.1 Review System and Safety Requirementsa
( The requirements specified in Appendix R IIIG and IIIL were reviewed and l the postulated fire event was fomalized. Systems objectives and require-l l
ments were established utilizing the loss of offsite power safety sequence s-i
A-5 diagram from the plant's Final Safety Analysis Report.
Task Status: Completed.
LaskR Evaluate Failure Modes & Effects. Formulate Anaylsis Procedure.
A detailed evaluation of possible failure modes due to a fire and their effects on shutdown equipment was conducted. Criteria were developed for the Safety Related and Associated Circuit review and a step-by-step detailed analysis procedure was approved. The procedure requires con-sideration of the following failures and effects:
A. Short Circuits to ground.
- 1. Loss of circuit component functions.
- 2. Possible loss of cable fault withstand capability.
- 3. Spurious operation.
B. Open circuits.
- 1. Loss of circuit component functions.
- 2. For open CT's, lass of associated breaker and a destroyed CT, C. Hot shorts.
- 1. Lo::s of circuit component functions.
- 2. Spurious operation.
- 3. Possible. loss of cable fault withstand capability.
In addition to formulating the review procedure, this task has identified the infonnation required in order to perform the analysis in an efficient manner.
Task Status: Completed.
Task 1.3 Develop Data Base for Analysis.
An essential part of the analysis was the determination of the equioment and -cables in each fire zone. "As Built" drawings were reviewed and equip-ment and raceways were listed for each zone. This .information, in conjunction t
A-6 with the inf:nnation in the cable and raceway schedule was used to provide the needed circuit and equipment information.
Task Status: Completed .
Task 1.4 Develop Computer Sort Capability.
In order to generate the required circuit information for each fire zone, identify the safety classification of circuits, the different types of Associated Circuits and different circuit applications (Power, Control and Instrumentation) - a computer Sort capability was developed. This programming effort, using the cable and raceway data base available for PNPS Unit #1, allowed for an increase in flexibility and efficiency of the analysis.
Task Status: Completed Task 1.5 Develop Safety Sequence Diagram. Develop Equipment Recuirerents.
This task was a continuation of Task #1.1. As the system requirements were defined, a Systems Sequence Diagram was developed based on the Station FSAR (Event 28 Loss of Offsite Power). For the systems detailed -in the diagram, all equipment, instrumentation and controls previously detennined to be Safety Related and active, were identified. From the above equipnent, the electrically operated equipment were identified.
Using P&ID's and FCD's, the instrumentation and controls that would be necessary to perform either system controlling function or provide necessary system status information were identified.
All the above equipment and canponents were then checked for intra-system redundanci's e whose single failure would not jeopardize safe systen operation.
These redundancies, which include redundant safety trains, alternate flow paths and equipment such as pumps and isolation valves were identified for the purpose of determining whether a system meets imposed failure criteria.
A-7 The incorporation of the above redundancies into the Safety Sequence Diagram for the postulated event provided the various " Success Paths" available us;ng multiple safety systems to achieve a safe plant shutdown.
Task Status: Completed .
Task 1.6 Preliminary Review of Safety Related and Associated Circuits.
All the designated Safety Related Cir:uits of each system identified as required for Safe Shutdown (in part or in full) were reviewed to determine all components affected by each cable #s loss due to fire.
Any Associated Circuits that are electrically connected with a Safety Re-lated Circuit were identified and reviewed to determine the components affected by their loss due to fire.
The above reviews took into consideration all possible types of faults except for the loss of fault withstand capability which is covered in task 1.8.
All relevant information was gathered on each circuit from drawings, vendor manuals and plant design change requests.
This review has created a " Master Data Base" from which data will be drawn for individual zone reviews.
Task Status: Completed .
Task 1.7 Correlate Circuits and Equipment.
This task involved the determination of the circuits that are associated with the Safe Shutdown equipment identified in Task 1.5. Equipment re-dundancies identified in Task 1.5 were translated to circuit redundancies -
an essential part for the zone review.
Task Status: Completed .
A-8 Task 1.8 Fire Zone Review - Phase I Phase I of the fire zone review is intended to identify the effects of fire-induced faults wnere Safety Related and Associated Circuits are routed through the same raceways or share the same enclosure.
The fault withstand capability of power cables is to be verified for each zone. In addition, the verification of proper fault protection for the circuits is to be verified.
Task Status: Currently in progress Expected Completion date: March 25, 1981 Task 1.9 Review Non S/R Circuits Required. Develop Data for Phase II.
Certain Safe Shutdown equipment (as detennined in Task 1.5) is associated with circuits that were not given Safety Related designations. As the components were identified, their respective circuits were determined and given a special designation to allow for consideration during the fire zone review. Upon completion of this portion of the task, an update of the cable data base was conducted. Fire Zone circuit outputs are currently being generated in order to permit the start of the fire zone reviews.
Task Status: Currenty in progress.
Expected Completion Date: March 25, 1981 l
g L
A9 Task 1.10 Fire Zone Review Phase II - Preliminary.
Using the information gathered in all previous tasks, cable sorts of each fire zone will be reviewed to determine the equipment lost. This determination will be reflected in the Safety Sequence Diagram fer the individual zone by the unavailability of a system or subsystem for a Safe Shutdown. If a " Success Path" exists after the loss of systens or subsystems 4; indicated on the diagram - the fire zone will be deter-mined as non-critical.
In no " Success Path" exists - the zone will be termed as critical and a preliminary list of circuits and raceways requiring modification or fire-protection will be developed for the individual zone.
Task Status: Expected stard - March 25, 1981 Expected Completion - April 25, 1981 Task 1.11 Review Preliminary Information. Develop Final Modification Requirements.
The infonnation developed in Task 1,10 will be reviewed to investigate possible extenuations such as credit for Operator action, sufficient spatial separation between redundant circuitry etc.
The result of this review will be a list (for each critical zone) of raceways and circuits requiring some modification. These lists *are to be used by other engineering activities in order to detennine feasibility, cost and installation schedules for the various options prescribed by
-requirements IIIG/IIIL of Appendix R.
Task Status: Expected Start - April 25,1981 Expected Completion - June 1,1981
A-10
.0 ALTERNATIVE SHUTDOWN LAPABILITIES EVALUATION 2.1 General Section IIIG of Appendix R defines an Alternative Shutdown Capability as a capability that is provided by re-routing, re-location or modifications of existing sytems.
It is the objective of this engineering activity to investigate the feasibility of re-routing cables and raceways, re-locating shutdown equipment or installing add-itional shutdown panels.
Several constraints and difficulties were encountered while pursuing this activity and therefore, necessitate the expenditure of considerable time and effort:
A. The availability of free space to which equipment or raceways may be relocated is very limited. Past NRC Safety concerns had resulted in numerous plant modifications which contributed to the high congestion of raceways and equipment in some plant areas or in the exclusion of certain ocher areas f:om possible future raceway routing and equipment location. This requires careful review and may result in the use of routing and installation methods not previously used in the plant.
B. One of the major requirements of the fire protection SER issued to the Pilgrim Station involved the installation of an Alternate Shutdown System that provides the shut-down capability if the plant's Cable Spreading . Room loses it's function due to a fire. The experience gained during the engineering, design and implementation of this system points out the complexity, if not the impracticality, of installing several such systems designed to be operated if cables and equipment in critical plant areas are lost due to a fire.
C. Since the major portions of this activity depend to a great extent on the results of the Safe Shutdown Analysis, only a limited evaluation and review can be accomplished.
until the results of the analysis are formulated and the extent of the modifications required in critical fire zones is determined. This constraint is reflected in the
A-11 scheduled completion dates of the tasks carried out in this activity.
2.2 Task Descritions Task 2.1 Conduct Preliminary Survey at PNPS to Locate Potential Alternative Methods.
A preliminary walk-through of accessible areas was conducted at PNPS in order to locate areas to which raceways may be re-routed or Alternate Shutdown panels may be located.
In addition, an investigation was initiated of the possible use of a ductbank outside the plant to route cables outside of potentially critical fire zones.
Task Status: Completed Task 2.2 Review Alternative Methods for Various Safety Considerations.
Any findings of Task 2.1 that may be worthwhile to pursue any further, will have to be verified taking into consideration not only the fire event but other Design Basis Accidents.
For example, areas of the plant were identified through which raceways may be re-routed for fire protection considerations (no fire hazards exist, no cables of redundant trains, etc.).
These areas contain piping which may present hazards during a high-energy pipe break event.
Seismic criteria have to be applied to assure that no aquipment or structures exist at the " free" areas that could subject the re-routed raceways to damage during a seismic event.
Task Status: Currently in progress.
Expected canpletion date: April 25, 1981
A-12 9
Task 2.3_ Conduct Preliminary Feasibility Review for Alternative Methods As the preliminary results of the Safe Shutdown Analysis become available, andeircuit and raceways are identified as requiring modification, the feasibility study for each zone can commence.
The evaluation process should take into consideration adequate separation from safety releted and safe shutdown equipment, voltage drops, possible barrier penetrations, core bore impacts upon struc-tures, raceway loadings, secondary containment breaching, physical implementation constraints, the need for a plant outage to imple-ment the modification and cost and schedule of implenentation.
Since the information obtained from the Safe Shutdown is preliminary and the time duration for this task is short, it is intended that the majority of the work will be performed after the start of Task 2.4 Task Status: Expected Start - April 25, 1981 Expected Completion - June 1,1981 Task 2.4 Final Feasibility Review.
This task is an extension of the previous task with the use of the finalized information pertaining to the required fire zone modifications.
An element essential to a complete and thorough evaluation is the ability to access areas at the plant which are inaccessible during normal plant oper-ation. This portion of the task is planned to take place during the upcoming plant Refueling Outage #5 currently scheduled to start in September 1981.
The final feasibility review will produce cost estimates and conclusions -
as to the possibility of pursing this prescribed option.
Task Status: Expected Start - June 1, 1981 Expected Completion - October 15, 1981
A-13 O FIRE BARRIER EVALUATI0ft 3.1 General Appendix R, Section IIIG.2 is specific in the options allowed for eningeering fire protection of redundant safety trains and associated nonsafety circuits located in the same fit 2 areas outside of the primary containment, to ensure that one of the redundant trains is " free of fire damage".
Two of the allowed options are the subject of this activity:
Option A: Separation of cables, equipment, and associated nonsafety circuits of redundant trains by a fire barrier having a 3 hr rating; or Option 8: Enclosure of cables, etc., of one redundant train in a fire barrier having a 1 hr rating. In addition, fire detectors and an automatic fire suppression system shall be installed in the fire area.
The purpose of this engineering offort is to investigate the feasibility of installing 1-hour or 3-hour fire barriers that could provide the fire protection prescribed.
The general approach taken is to survey the market for proper available materials, find typical raceway configurations at the plant and test the application of fire barrier on these raceways.
Several points and limitations encountered during the early tasks are noteworthy since they represent questions that are not yet resolved within the nuclear industry:
A. The fire barrier shall be rated by exposure to the standard test fire as defined by the Anerican Society for Testing and Materials in ASTM E-119, which was devised for buildings, i.e., walls, floors, and roofs, (See Appendix R, comments and resolution, Section IIIM). This test is conducted by exposing the barrier to the standard fire on one side and monitoring the cold side conditions. The barrier is acceptable for the specified time if the cotton waste on the unexposed surface does not ignite, if a hose steam does not penetrate the barrier after exposure to the standard fire,
A-14 and if the cold side temperature remains below the initial temperature plus U
250 F. Application of this test method to certain barrier configurations, such as a cable tray or conduit enclosure (cocoon), is uncertain. However, it is clear from Appendix R that the " standard test fire" should be used for fire barrier testing (i.e., the ASTM E-119 time temperature curve).
B. The tenn " free of fire damage" is not defined. In its strictest sense, this might mean the cables, etc., cannot be exposed to ambient temperature above design (usually 40 C) during the test time interval corresponding to the fire barrier rating and suffer no damage during the hose stream test.
In a less strict sense, it might mean one can demonstrate with margin that the cables, etc., are able to perfonn their function during the test inter-val, but not necessarily for any extended time thereafter.
C. The word " enclosure" is undefined. The word could be interpreted to mean a room or a tight-fitting wrap.
The evaluation of fire barrier applicability is conducted and based on the following assumptions:
- 1. The concept of a tray and conduit wrap is assumed to to satisfactory Evea though this type of " enclosure" is practical and meets the requirements of Appendix R ,NRC acceptance has yet to be determined. Testing of the wraps as applied to Pilgrim Station will be necessary. The ASTM E-119 standard test fire will be used.
- 2. No significant detrimental effect on the cable is expected to result from enclosing or wrapping trays or conduits since these raceways contain either low voltage level control . cables or power cables that are loaded only for snort durations of time. Should other power cables have to be enclosed, the effects of the barrier enclosure on cable capacity, due to , temperature rise, will have to be determined and taken into account.
A-15
- 3. Demonstration that cables are " free of fire damage" during the rated fire duration is interpreted as meaning that no ignition of cable insulation and jacket material while cable circuit integrity is maintained with rated voltage and current applied. A hose stream test will be used.
It was realized by BECo that although no prior NRC approval or review of the designs for fire barriers is required of us, it will be prudent to arrive at a concensus within the industry and with the NRC as to the acceptability of the proposed materials and configurations and the assumptions made in arriving at the specific designs.
3.2 Task Descriptions Tasx 3.1: Sunnary of Barrier Materials (1-hr barrier) .
Information was obtained for fire barrier materials from manufact-urers and their catalogs. The manufacturer's capabilities in terms of product availablity and q0alification testing was taken into con-sideration. The manufacturer's su veyed were Babcock and Wilcox, Carborundum, Johns-Manville, Eagle Picher, U.S. Gypsum, H.H.rtobertson, Carboline, Dow Corning, 3M Company and AVC0 Systems.
Task Status: Completed.
Task 3.2 &
3.3: Survey characteristics and configurations.
I In order to arrive at an avaluation as to the feasibility of in-i stalling fire barriers, a preliminary survey was conducted at the plant to locate and document some typical raceway characteristics end layout configurations. This task is essential for proper evaluation t
since it provides the infonnation as to the physical limitatioris of installing any proposed barrier-as well as the configurations that will have to be tested in a qualification type test. In addition,
, those configurations will be used in develping installation procedure i
A-16 criteria. The plant's Cable Spreading room was chosen as a de-tailed survey area. This area presents many unique configurations and interferences and, therefore, can produce representative config-urations for the other areas of the plant.
In addition to the Cable Spreading room, typical configurations at other areas of the plant were located and documented.
Task Status: Completed Task 3.4: Barrier Material Selections (1-hr. Barrier)
After the initial material information was gathered, an evaluation was made taking physical limitations into account as well as available testing infonnation. Two basic types of 1-hour fire barriers were found acceptable for further investigation: (a) Flex-ible blanket insulation constructed of ceramic fiber (kaowool or similar) (b)' Intumescent material (3M Company's FS-195 or similar). Properties of the abovematerials were studied in order to incorporate that information into possible future test procedures.
Task Status: Completed.
Task 3.5: Develop Test Configurations (Conceptual) 31 different configurations were identified as existing at the plant and may require qualification testing. These configurations were 3-grouped into categories, each incorporating similar configurations tc be qualfied by the same test.
No attempt
.The configurationsconsist of cables, trays and conduits.
was made to detennine the types of cables, conduits and trays to be-used.
Task Status _: Canpleted.
~
r ,
A-17 Tasts 3.6 &
3.7: Zone Equipment Survey and Conceptual Designs for Equipment Protect, ion In order to provide fire protection to equipment necessary for a safe plant shutdown, the equipment in each zone has to be doc-umented. This is accomplished primarily by the Safe Shutdown Analysis. Under this task,a typical zone was selecte6 and a detailed evaluation was made as to the equipment available and the means to protect it. The purpose of the tasks was to establish guidelines for equipment protection and provide information for an order-or-magnitude evaluation (to be carried out later).
The feasibility of in-cabinet fire detectors with an alarm system was investigated. Cable separation or in-cabinet suppression were investigated only to a limited extent for lack of information as to the circuits and specific cabinets.
The possibility of ties to the existing plant fire detection system was evaluated.
Task Status: Completed.
Tasks 3.8, 3.9 & 3.10: Prepare Conceptual Test Procedure. Interface with Labs and '
Mfr.'s on Tests.
A preliminary effort is currently under way to establish guide-lines and criteria that will be used to develop the test procedures.
The use of ASTM E-119 test procedure is being considered and the achievability of its acceptance criteria for the specific configura-tions and physical limitations is being eva7 .
. . Additional consider-ations are given to the monitoring requirements (temperature, circuit integrity etc..). Available qualification testing infonn-
-ation is being reviewed to determine their applicability to the configurations to be tested.
=_ .- -
A-18 l
Discussions with test facilities are underway to gather the necessary information. Dimensions of the furnace and the use of BECo's configurations were discussed. Also, information on fab-rication of test rigs schedule etc., are being obtained.
Task Status: Currently in progress.
Expected Completion Date: April 1, 1981 Task 3.11: Presentation of Test Procedure to NRC and Industry.
BECo plans to present the preliminary information on 1-hour fire barriers and the proposed conceptual test procedure in order to arrive at an agreement as to the acceptability of the assumptions, procedure and acceptance criteria.
Task Status: Expected Start: April 1, 1981 Expected Canpletion: June 1, 1981 Task 3.12: Purchase liaterials, Fabricate Test Assemblies Incorporate Comments The materials required for testing will be purchased and equipment will be assembled in parallel to task 3.11. As comments and suggested changes to the proposed test procedure and criteria, are obtained, they will be incorporated into the procedure and the physical setup of the equipment.
Task Status: Expected Start: April 1, 1981 Expected Completion: June 1, 1981 Task 3.13: Conduct Tests.
Time is allowed for conducting tests, evaluating their results, re-testing (if necessary)_ and producing the test reports.
~ Task Status: Expected Start: -June 1, 1981 Expected Canpletion: September 1,^ 1981
=
A-19 Tasks 3,14, & 3,15: Survey available Material. Choice of Material (3-hr. Barrier)
A manufacturer's survey similar to the one conducted for 1-hr barrier was carried out for 3-hr barriers. It was noted early into the survey that the availability of qualified 3-hour barrier materials was very limited. Therefore, materihls surveyed for 1-hour barriers were considered. Calculations were perfomed to detennine a theoretical thickness that will provide the 3-hour barrier protection. A conceptual design was proposed which utilizes a qualified 3-hour barrier.
A composite panel section furnished by H. H. Robertson (or equivalent) will fonn the enclosure and will be fastened to steel framing members. The panel's weights necessitates special designs for seismic supports and the need to test the panel for seismic resistance.
The supports of the enclosure will require fire protection.
Although tested and qualified as a fire barrier wall, it is not certain that this material will perfonn similarly in the enclosure configurations that are intended for use at Pilgrim Station.
l Typical raceway configurations were chosen and conceptual i
designs were provided for them. In addition to the enclosure, I
the structure will consist of many supports and framing members that will have to be added to the existing system.
Task Status: Completed .
Task 3.16: Preliminary Design and Feasibility Study .
As additional design details are provided, a preliminary evaluation can be made of the conceptual design relative to existing conditions at the plant.
Design and installation of the barriers will be complicated by the L
A-20 weight of the fire barrier material, the number of inter-ferences, seismic considerations, location of th cable trays near the ceilings, and proximity of the cables to be protected to nonsafety cabling and the opposite train. Most of the enclosure and support system is expected to require detailed engineering. Installation will be subjected to the added compli-cation caused by radiological conditions.
Task Status: Expected Start: March 1, 1981 Expected Completion: June 1, 1981 Tasks 3.17. 3.18: Feasibility of Barrier Inst'allation Given Actual Configurations.
As the exact required modification to specific cables and raceways will become known, the final feasibility study can comence..
Suchissuesastheimpactofthefirebarriersontheadequacy of the raceway support systems, the ventilation systems, the accessibility to equipment for the purpose of operation and main-1 tenance and ampacity rating of cables will have to be considered.
If a suppression system is to be installed in addition to the i- fire barrier, the protection of the Safety Related equipment from inadvertant operation or pipe rupture and the adequacy of floor drains will have to be considered.
Installation of parts of the fire barriers may require a plant shutdown. This will have to be considered and factored into the evaluation.
The final. feasibility review will also produce a composite cost est: mate for the alternative of barrier installation.
This estimate is to be used when evaluation of all the options prescribed in Sections III.G.2, III.G.3 will take place.
Task Status: Expected Start: June 1, 1981 Expected Completion:- October 15, 1981
A-21 4.0 DEDICATED SHUTDOWN SYSTEM STUDY 4.1 General The protection of the safe shutdown capability i' .ne event of fire with the use of a Dedicated Shutdown System (DSS) is prescribed in Section IIIG.3 for fire areas where none of the fire protection requirements of pragraph G.2 are satisfied or when both redundant shutdown equipment may be subject to damage from fire suppression activities, from inadvertant operation or rupture of the suppression systen.
At the initiation of this study, BECo had recognized that although the DSS should be evaluated as one of several alternatives in the effort to protect the safe shutdown capability of the plant in the event of ' a fire, the study of such a system should not be limited to the criteria and goals set forth by Section IIIL of Appendix R. BECo believes that several alternatives to a DSS design may be beneficial for reducing plant risk from comon mode and plant transient events. These benefits, when combined with the benefits from improved shutdown capability in the event of fire could justify an otherwise economically unjustifiable system.
The study program includes, therefore, a comprehensive plant risk reduction evaluation with different alternatives of a DSS. The basic elements of the program include problem definition, specification of criteria, developnent of several alternatives and evaluation of the alternatives with respect to risk reduction versus costs.
4.2 pskDescriptions
. Tasks 4.1 & 4.2: DSS Preliminary Feasibility and Conceptual Design. Interdisci-plinary Review.
The purpose of this task was to test if, from an engineering and operations standpoint, a DSS concept is feasible. At this early stage BECo did not intend to firTn up a conceptual design upon which details could be addec later but, rather, test if component and interface requirements of a DSS design (one out
A-22 of many possible designs) result in a manageable concept which could be pur-sued further. A conceptual description of a DSS was formulated using the base line criteria provided by Section IIIL of Appendix R , selecting decay heat removal capability at one hour after shutdown, and vaunding the ,
upper limit of system flow rate using NUREG-0460, Alternate 4 order of magni tude boration rate. This level of detail of criteria was believed to be commensurate with the level of detail required for the preliminary investi-gation. A rough order-of-magnitude estimate of the size of components, cost and time required for installation of such a system was arrived at.
The concept was then reviewed by BEco personnel of various disciplines (Nuclear Operations, Engineering and Operations Support). Comments received were incorporated into the concept.
Task Status: Completed.
Tasks 4.3, 4.4, & 4.5: Develop Rough Order of Magnitude, Cost Estimates, Develop a detailed Study Plan, and Make decision on carrying out the-Study.
Using the conceptual ^ design as base line, cost estimates were arrived at for the DSS. An evaluation and estimate was made of the potential costs the BEco will incur if other options were pu'rsued to protect the safa shutdown capabil-ity (i.e. Alternative Shutdown Capabilities or the optivas prescribed in Section IIIG.2 of Appendix R). This was compared to the potential cost of the Conceptual DSS.
A similar evaluation was obtained from the company's task forces that are engaged in the resolution of other safety and operations issues (either in the evaluation,or e.sgineering stages). . A plan is currently being developed by Stone & Webster Engineering Corp. to scope the overall engireering effort that will be required.if the company elected to pursue the effort any further.
A-23 This plan will identify the manpower and capital rescurces required for a detailed study of the Dedicated Shutdown option.
Upon completion of this effort, a management decision will be made whether to proceed with a detailed study or preclude the DSS option.
Task Status: Currently in progress Expected completion due: March 25, 1981 Tasks 4.6,4.7 & 4.8: Evaluate Safe Shutdown Capability, Define Acceptable Alternate Designs and Criteria.
As the results of the Safe Shutdown Analysis became available,an evaluation of the existing shutdown capability will be perfomed.
A similar evaluation will be performed taking into consideration a DSS.
Based on the functional criteria set by Section IIIL of Appendix R, different design alternative of a DSS can then be developed.
After detailing the plant interfaces and the component requirements an opti-mizing process can determine the DSS most suitable to the plant that could satisfy the r,equirements of Section IIIL.
A detailed cost and schedule will then be' prepared for this design.
Task Status: Expected Start: March 25, 1981 Expected Completion: July 20, 1981 Tasks 4.9 & 4.10: Evaluate Other Issues, Evaluate Other Options.
A process of identifying the safety and operating issues which could be sat-isfied with the installation of a DSS is to take place in this task. As issues are identified, their functional criteria will be defined and compared to the critert set forth in task 4.7. Additional features can then be consid-ered for each of the alternates that could safisfy the added functional criteria.
A-24 For each issue a comparative study can be made of the cost and method of re-solution with or without the use of a Dedicated Shutdown system.
When the results of the issues study is available, an optimization process can take place to determine the best set of functional criteria and features that could be added to the design arrived at in task 4.8. This will be achieved by weighing benefits vs. costs of issue resolution and will define the degree of applicablity of a DSS to the various issues.
Task Status: Expected Start: March 25, 1981 Expected Completion: August 5, 1981 Task 4.11: Preliminary Decision on DSS 4
As detailed costs and schedule is available for a DSS that satisfies Appendix R critaria,a decision can be made whether to pursue the issue or stop any further study due to prohibitive costs or impracticality of installation.
Task Status: Expected Start: July 25, 1981 Expected Completion: August 5,1981 Task 4.12: Evaluate Total Impact If a positive decision was made in task 4.11, the integration of the add-itional features into the design can be evaluated to determine total costs, schedule, physical interface with existing systems and the impact of a DSS installation on plant risk.
A determination as tc the viability of the DSS option can then be made and used as an input to the evaluation process of Appendix 'R options.
-Task Status: Expected Start: August 5, 1981 Expected Completion: October 15, 1981
ATTACHfiENT B B REQUEST FOR EXEMPTION
- 1. EXEMPTIONS TO REQUIREMENTS OF SECTION III(G)(2) PERTAINING TO DIFFERENT AREAS AT PILGRIM STATION UNIT #1 A. The Cable Spreading Room Boston Edison Company petitions the Comission for an exemption from requirement for its Cable Spreading Room based on its assertion that the installed alternative shutdown system per SER requirements satisfy the intent of Section II"(G) in that an orderly shutdown can be achieved effectively after a fire is detected in the CSR. Boston Edison had com-pleted the implementation of this Alternative Shutdown System in response to the requirement in the Safety Evaluation Report. Boston Edison has spent appruximately $750,000 to this effort.
Design details for this major modification had been submitted in January 1980 for staff review prior to implementation as required in the Safety Evaluation. Isolation switches and alternate oower feeds were provided for all redundant safe shutdown circuits passing throuch the CSR. As part of the design criteria, these isolation switches will be operated within 20 minutes of a fire being detected in the CSR and the procedure for safe shutdown is ir.itiated from the Control Room.
In order to assure a fast response time, Boston Edison had implemented extensive defense-in-depth fire protection measures in the Cable Soreading Room. All electrical Cables in one of the redundant raceway trains as well as the cables in the lower-most cable trays havebeen sorayed with Flamemastic
- 77. Smoke detectors and automatic C02 System are in place in the Cable Spreading Room. Entry into and out of the Cable Screadina Room is controlled by a two-man rule through access card keys.
As required by the .backfitting provision contained in Apoendix R, Boston Edison Company has evaluated the installed system and has determined that the installed system demonstrates that the public health and safety is properly protected. The functional capabilities of the installed system meet the intent of Section III(G) 70 demonstrated in our design submittal (BECo Letter #80-19 dated January 31,1980). .
We have identified the cost as well as the technical difficulties in in-stalling a 1-hour fire barrier enclosure for one of the redundant raceway trains in the Cable Spreading Room. The cost is estimated to be $1,000,000.
Appendix R, though j discredits cable coating as a fire barrier, Boston Edison is assured that the combined defense-in-depth protection existing in the CSR provides adequate protection and response time comparable with the suggested option in Appendix R.
In conclusion, Boston Edison Company requests the Staff to review its design submittal on the Alternative Shutdown System for the Cable Soreading Room. Should your review identify a need for clarification on any technical matters, Boston Edison Company would be more than willing to oresent suoportive documents to justify the design details.
8-2 B. Main Control Room Boston Edison Company requests an exemption from the requirenents of Section III(G)(2) being applied to the liain Control Room based on the assertion that the plant could be brought to a safe shutdown using the Alternate Shut-down System designed and installed for the Cable Spreading Room. BECo had submitted design details for this modification by January 1980.
Installation of this system was carried out by the end of outage in May 1980. Our exemption asserts that the specific requirements of Section III(G)(1) is satisfied by this alternate method of shutdown.
We would also point out that Boston Edison has a detailed procedure to safely shutdown the plant in the event the Control Room became uninhabitable.
Pilgrim Station Procedure 5.3.1 " Shutdown from Outside the Control Room" describes this alternate method of shutdown in detail. BECo had submitted this for staff infonnation by BECo Letter #78-135 dated February 27, 1978.
BEco has also carried out safe shutdown evaluations of all control panels located in the Main Control Room and has recommended and installed early warning automatic smoke detection system for six of these panels. We have also provided an extensive breathing air system which can supoort three men for 7.91 hours0.00105 days <br />0.0253 hours <br />1.50463e-4 weeks <br />3.46255e-5 months <br />. All electrical cables installed in trays at the ceiling in the Control Room were fire proofed with Flamemastic 77. A water hose station was installed in the corridor outside the main entrance to the Control Room.
Kitchen located adjacent to the Control Room was fitted with a microwave oven as a possible precaution against having any fire originating in the electric stove. All these fire protection measures together with constant availability of plant personnel assure that any fire would be detected and controlled imediately.
In view of these approved fire protection features in the fiain Control Room, Boston Edison Company requests an exemption from the requirement to install fixed suppression systems in this area.
Indeed, potentially serious conditions would be likely to arise in the Control Room as a result of effects of water upon sensitive equioment, and the likely interference with the operators ability to react effectively to the ongoing emergency. In this respect, installation of a fire suppression system may actually be detrimental to overall safety at PNPS Unit #1.
C. Switchgear Room B The Safe Shutdown Analysic that was carried out for this fire zone had identified certain safety Division A raceways passing throuah this zone.
The concerned raceways originated in Switchgear Room A. The location of these raceways was site verified and were protected by encasing then with fire resistive materials, of the kind used for fire proofing steel beams for 3-hour rating at PNPS Unit #1. The location of these raceways and the minimal length that was needed to be prctected would assure the inteority of the circuits that were protected. BECo has also installed other fire preventive measures such as:
- 1) Full coverage automatic smoke detection system
- 2) Hose reel stations immediately outside of the entrance doors
- 3) Exposed structural steel beams and columns were fire proofed for 3-hour rating
B-3 In its effort to accomplish a defense-in-depth fire protection for all areas of the plant, Boston Edison Company has surveyed each area for a potential exposure fire based on the investigation for transient com-bustible material in transit through or in use in the areas investigated.
For the Switchgear Room B, it was estimated to be 1 Gallon oil. Based on NP-1675), we Factory Mutual Research Corporation report for EPRI (
conclude that a fire involving 1 gallon of fuel oil would not have any effect on the concerned safety related A raceways because of their locations and the protection afforded to them.
D. Vital MG Set Room The Safe Shutdown Analysis that was perfomed for this area identified RHR Inboard Isolation Valve, 1001-50 as requiring safeguarding from a fire involving Safety Division B raceways. Structures, systems and companents of both the Safety Divisions A & B were evaluated to determine if one train of systems necessary to achieve and maintain hot shutdown conditions from either the control room or emergency control station is free of fire damage.
As part of BECo effort to design and install an alternative shutdown system for a fire in the Cable Spreading Room,which was mandated per the SER issued to PNPS Unit #1, Valve 1001-50 has been provided with an alternate oower feed to enable it to open for shutdown cooling mode. For a fire in the Vital MG Set Room, the isolation switch,provided for this valve per the Cable Spreading Room modification, will be used.
Extensive defense-in-depth fire protection measures for this area have been provided to assure early detection and. suppression of fires. These include: 1) Ionization and photelectric detectors 2) hose station out-side the door and 3) majority of cable trays were sprayed with Flamemastic
- 77. A survey carried out for transient combustible materials in use in this area, has determined the maximum transient conbustible material to be 1 gallon of lube oil used to service the Vital MG Set bearings. Based on EPRI report NP 1675, it can be safely assmed that a spill-fire involving 1 gallon oil would have no effect on the concerned raceways.
BEco's request for an exemption to the requirements of III(G)(2) being l
applied to Vital MG Set Room is based on assertion that the existing fire
! protection features in the fom of equipment, structures and procedures would assure that the intent of Section III(G)(1) is satisfied.
E. Reactor Building Closed Cooling Water Pump Room B The results of Safe Shutdown analysis that was performed for this area identified the raceways for both Salt Service Water Pumps in this area.
l This area being a Safety Division B, it was recomended that fire protec-tion measures be made available for safety Division A raceways. Transient Combustible usage for this area had determined a maximum of 2 Gallon spill could occur between any two RBCCW pumps. A large number of heavy equip-ment is located in this area contributing to the heatsink. The room has high ceiling and large vol m e. As part of Boston Edison recomendations to protect the only raceways located above the pump area, marinite boards will be installed underneath the trays on top of pumps. Safety Division raceways are located at more than 15 feet from the floor and are nowhere near the probable oil spill area.
B-4 Based on an EPRI study ( NP 1675), it can be safely concluded that a postulated fill involving 2 Gallon lube oil between any two pumps would not have any detrimental effect on Safety Division A raceways as they are over 20 feet from the oil spill area. Early warning smoke detectors are also installed in this area.
BEco's request for an exemption to the requirements of.Section III(G)(2) being applied to the area is based on its assertion that one train of safety Division system will always be available to effect shutdown conditions .
F. Open Area - East Half, - Reactor Building Elev. 51' - 0" Boston Edison Company's safe shutdown analysis submittal for this area had identified a number of safety Division A raceways that required fire protection measures to assure that the capability to effect a safe shut-dcwn is not jeopardized due to a postulated fire in this area.
Boston Edison has reassessed its comitment to control transient combustible materials and has practically eliminated any transit of fuel oil through this area.
Since its submittal, Boston Edison Company has installed 1) a number of smoke detectors in this area, 2) 8-hour emergency lights and, 3) addition-al sprinkler coverage for the adjoining Recirc MG Set Area which has a fluid coupling with large quantities of oil.
We plan to install marinite barriers to protect a number of Safety Division A raceways from a common fire with safety Division B raceways.
Based on the modifications so far accomplished in this area together with what is planned, assures the availability of one redundant safety Division for effecting plant shutdown. Therefore, Boston Edison Company requests an exemption to the requirement of Sect. III(G)(2) for this area, G. Switchgear Room A, Fire Zone 2.2, Radwaste and Control Building, Elev. 37' - 0" The Safe Shutdown Analysis that was submitted for this area had determined that a postulated fire in this area would have no detrimental effect on safe shutdown of the plant. However, we have proceeded ahead and installed a hand hose reel station imediately outside the area, PVC cables were sprayed with Flamemastic 77 and steel beams were fire proofed for 3-hour rating.
As part of our re-assessment to control transient combustible for this area, being a non access through area, we have determined that no oil passes through this area. This will preclude any transient fire in this area.
Our reouest for an exemption to the requirements of Sect. III(G)(2) for this area based on the assertion that the requirements of Sect. III(G)(1) are satisfied. Safe Shutdown in the event of a fi're in this area is always
. assured.
B-5 Feedwater Heater "B" - Turbine Building Elev. 6' - 0" to 47' - 0" H.
Boston Edison Company's safe shutdown analysis submitted for this area identified a number of safety Division A raceways that required fire protection measures to assure that one train of systems required for safe shutriown is available at all times. In order to achieve this, we plan to wrap Safety Division A conduits with fire resistive materials. Boston Edison will consider installation of marinite boards below these concerned conduits to protect them from a postulated fire. No fuel oil is expected to be transmitted through this area. The area is covered by automatic fixed water suppression systems.
The PVC cables in the area were sprayed with Flamemastic 77.
Based on the fire protection measures presently available in this area together with our recomended measures would assure that the intent of Sect. III(G)(1) is met. Hence, Boston Edison Company requests an exem-ption to the requirements of Sect. III(G)(2) for this area.
I.
CRD Module Area - West - Reactor Building Elev. 23' - 0" The Safe Shutdown Analysis that was performed for this area identified certain critical safety Division A raceways that required fire protection measures to assure availability of one shutdown safety train. A fire which damages the shutdown systems of both the safety Divisions at the same in-stant would be improbable as these two safety divisions are separated by a distance of more than 6 feet at the narrowest point. A number of fire protection measures were recomended for implementation and a majority of them have been completed. The remainder will be completed as soon as approval from the staff is obtained for the submitted designs.
Boston Edison has, through procedures, maintained tight control on the trans-A maximum portation of transient combustible materials through this area. No of 5 gallon cleansing oil is estimated to transit through this area.
flame infringement of safety Division A raceways are anticipated because of their location in this area. The only probable place where an inadvertant oil spill ~could be expected is near the equipment hatch. Marinite boards will be considered to protect the safety Division A raceways from a postulated spill in the equipment hatch area.
Boston Edison Company requests an exemption to the requirements of Sect. III (G)(2) for this area based on the assertion that the fire protection require-ments to meet the intent of Sect III (G)(1) are satisfied by the existing system of fire protective measures and those that are recomended for imple-mentation. Since our original safe1)shutdown an extensive submittal for this area in system of smoke detectors January 1980, we have installed:
in this area, 2) sealed beam 8-hour emergency lights at strategic locations and 3) new hose statior in the truck lock. All other recomendeo measures will be implemented based on a favorable action on this exemption request.
m_m_ _ . _m. m , . _ - - _ _.
1 I B-6 .
k J. Control Rod Drive Module Area - East - Reactor Building Elev. 23' - 0" i
The Safe Shutdown Analysis prepared for this area identified a number of safety Division B shutdown systems that would require protect- .
- ive measures to assure their availability in case of fire in this area.
Boston Edison has completed a major part of all modification that were
. recomended in our submittal to the Staff. Certaii modifications such as wrapping the safety Division B conduits with protective wrap around shield for protection from an exposure fire have not been attempted pending
- approval on the design from the Staff. Boston Edison will undertake to com-l plete this as part 'of an original commitment.
We also reassessed our station control on transient combustible ma-j terials in order to define the quantity of transient combustible materials in transit through or in use in the areas that are being investigated.
Based on the configuration of Safety Division B raceways in thi:: area, Boston Edison is considering the use of protective barriers similar to marinite boards below the Safety Division B raceways throughout the fire
+ zone. No quantity of oil is nonnally brought through this area. There is no equipment in this area that requires oil lubricant or large quanti-ties of oil for fluid coupling. However, as a nomal maintenance activity
, a five gallon cleansing fuel could be assumed to be brought through this area. Based on EPRI report ( NP 1675), it can be concluded that the maximum flame height from such a spill would not damage any of Safety Div-2 ision B raceways with all the protective measures that were completed or are recomended for installation.
Boston Edison Company requests an exemption from the requirements of
- Sect. III(G)(2) for this area based on the assertion that the fire protection l
measures that are in place or those that are recomended for implementation.
- satisfy the intent of Sect. III(G)(1) in that a safe shutdown is avail-
- i. able for a postulated fire in this area. We would state that the specific i fire protection measures. outlined in Sect. III(G)(2) of Appendix Rif applied i t
l for the safety Civision B raceways would mean providing 3 Hour barriers.
- - Boston Edison has evaluated available industry accepted 3-Hour fire barrier
! materials for this purpose. . With al_1 seismic installation together with the L large number-of raceways that are in this area would make such an installation
[
counter protective to the raceways. Rerouting all Safety Division 3 race-l ways outside the area would also be counter protective in that it may actually degrade safety systems in adjoining areas. Hence, assessing what our
- presently installed defense-in-depth fire protective measures have achieved l- by ways of response time along with those recomendations still to be L
we conclude that we have provided the needed assurance that
- . Section implemented III (G)(1) requirement is met.
e f
5
. C: L~.- .-- . . _ . -, -;; , - - ;_ ..
B-7
- 2. The Last Paragraph of Section III(G)(3)
The last paragraph subsection III(G)(3) of Section III(G) in Appendix R states: "In addition, fire detection and a fixed suppression system shall be installed in the area, room or zone' under consideration".
As stated in a foot note to the rule, which defines Alternative Shutdown Capability, it would mean relocating one of the critical safe shutdown system raceways and equipment to outside the critical area leaving the area circumvented with only one redundant safety system.
Boston Edison Company petitions tiie comission for an exemption from this requirement to provide fire detection and fixed suppression in the area that is circumvented based on its det3nnination that this requiremer:t does not add addit'onal protection (as required by the back fitting provisions contained in CFR 50.109) to the public health and safety beyond that which would be provided by the relocation of critical circuits.
In addition, this requirement could be construed as one that would need installation of fixed suppression and fire detection system in all areas of the plant with one safety division system only irrespective of whether a relocation was carried out or not. The requirement adds substantially to the cost and safety problems as in many cases, due to plant configuration, fixed suppression would involve using water. This would have consequential effect on electrical equipment, drainage and disposal.
Smoke Detection Systems have been installed in all major areas at Pilgrim.
Hose Station coverage has been proved to be available as a manual suppression option for fire suppression for all areas. This capability has been demon-strated as part of an evaluation that was perfonned to satisfy staff's concerns. Many new hose stations have been installed throughout the plant.
In conclusion, Boston Edison would state that the implementation of the special requirement discussed as part of this exemption request would not add substantial additional protection and as such cannot be justified and is thus necessary.
B-8
- 3. SECTION 11101) FIRE BARRIER CABLE PENETRATION SEAL QUALIFICATION This section states that penetration seal designs shall be qualified by test; that are comparable to tests used to rate fire barriers. ASTM E 119-1971 is one of the most accepted methods of testing that is followed by the industry to rate barriers.
This test specifies that the barrier being tested would quality fc-its rating if, during the specified time, it contains the fire, an.
- 1. ; surface unexposed to the fire does not heat up suffit.iently to gnite cotton waste or the temperature does not exceed 2500F above ambient.
It is the intention of Boston Edison Company to identify relevant dif-ferences in criteria specified in ASTM E-119 and IEEE 634 as they are used to qualify fire barrier penetration seals and to present to you our request for an exemption. As stated earlier, an antient temperature of 2500F is set as the limiting temperature on the cold side for quali-fying a fire barrier. A fire sensitive barrier tested and qualified through ASTM E-119 has a rglatively low thermal conductivity so that it can maintain a 1300 - 1600 F temperature difference between the face exposed to the fire and the opposite face. A cable penetration has a metallic electrical conductor which has a very high thermal conduction.
It may have many large copper conductors and steel trays or conduits or metal parts of the penetration, all of which pass through the barrier.
On the cool side of the barrier, these metal parts are necessarily at a higher temperature than the wall adjacent to the penetration. The fire stop material filling the interstices between cables or between cables and the barrier should give comparable thermal conductance to the barrier itself, in addition to resisting the fire. Hence, to use the same test (ASTM E-119) for rating barriers as well as cable penetration seals would be an impossible task. Pass - Fail criteria specified in IEEE 634 are more realistic and Boston Edison had set thir criteria for its testing.
Through this submittal, Boston Edison Company petitions the commission for an exemption to this requirement: " Fire barrier cable penetration seal shall be qualified by test comparable to tests that are used to rate fire ba rriers ". This is based on our assertion that the pass - fail critiera specified in IEEE 634 along with the time-temperature curve specified in ASTM E 119 for the furnace set up would satisfy the intent of Section III(M).
As the primary intent of fire barrier cable penetration seal qualification is to assure that no fire propagation occurs from one side of the fire barrier to the other side through the penetration opening, it can be stated that the requested exemption if, approved would not degrade public health and safety as the seals qualified through IEEE 634 would accomplish the intent of the requirement.
P
B-9
- 4. SECTION III(J), EMERGFNCY LIGHTING This section requires: "Energency lighting units with at least an 8-hour battery power supply shall be provided in all areas needed for operation of' safe shutdown equipment and in access and egress routes thereto". As specified in the Appendix R, the requirements of this section are to be backfitted on all operating plants irrespective of the licensee having had an approval from the NRC Staff as satisfying -the provisions of Appendix A to Branch Technical Position BTP APCSB 9.5-1 reflected in staff fire protection Safety Evaluation Reports issued prior to the effective date of this rule.
Boston Edison Company had an acceptance from the NRC Staff on its mode of commitment with respect to 8-hour emergency lights that were installed at different strategic locations at Pilgrim Nuclear Power Station as per Item 3.1.5 of the SER. A detailed evaluation had been carried out to identify locations where these 8-hour emergency lights would be required. 8-hour emergency lights were installed in all required locations. Pilgrim Station has other plant lighting systems that include: normal AC lights powered from non-safety related switchgear; emergency AC lights powered from division "A" or "B" _ safety-related switchgear; emergency DC lights pavered from either division "A" or "B" safety-related switchgear supplied battery chargers; and installed portable emergency lighting units powered from self contained batteries'which are continuously charged. In addition, battery operated hand lights are available for emergency use by the fire brigade.
Boston Edison Company petitions the Commission for an exemption to the require-ments of Section III(J) for its Pilgrim Nuclear Power Station based on BECo's assertion that the intent of the requirements stated in Section III(J) is satisfied by our existing system that was installed as per the commitment in the Safety Evaluation Report.
B-10
- 5. III(0) COLLECTION SYSTEM FOR REACTOR COOLANT PUMP The requirement of this section requires that an oil collection system shall be designed, engineered, and installed for the Reactor Coolant Pump such that its failure will not lead to fire during normal or design basis accident conditions.
Thh requirement also specified its scope of application to those containments which are not inerted during normal operation. This section is one of three sections which the Appendix R mandates to be backfitted on all operating plants irrespective of having had an approval from the NRC through the Safety Evaluation Report issued to them.
Boston Edison Company has determined that the requirements of Section III(0) has no impact on Pilgrim Nuclear Power Station as its containment is inerted during normal plant operation. Boston Edison Comoany wishes to state that it is not its intention to request for an extension from the requirements of Section III(0) as they do not apply to our plant. However, should there be a procedural need for an exemption in such a case, Boston Edison wishes to consider this as an appropriate exemption for exclusion from the requirement of Section III(0).
1 s
e