ML20052F355
| ML20052F355 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 04/30/1982 |
| From: | Lainas G Office of Nuclear Reactor Regulation |
| To: | Vandewalle D CAROLINA POWER & LIGHT CO. |
| References | |
| NUDOCS 8205120378 | |
| Download: ML20052F355 (18) | |
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April 30,1982 Docket tio. 50-155 l
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Mr. David J. VandeWalle Q
G liuclear Licensing Administrator 2
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Consumers Power Company 1
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6 1945 W. Parnall Road y
Jackson, Michigan 49201 s
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Dear Mr. VandeWalle:
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SUBJECT:
FIRE PROTECTION RULE - 10 CFR 50.48(c)(5) -
RilATIVE SAFE SilVTDOWil - SECTION III.G.3 0F APPEllDIX R T010 CFR 50 -
BIG ROCK POINT The Fire Protection Rule (10 CFR 50.48 and Appendix R to 10 CFR 50) became 4
f effective on February 17, 1981. Paragraph 50.48(c)(5) required submittal of design descriptions of modifications needed to satisfy Section III.G.3 of Appendix R to 10 CFR 50 by March 19, 1981.
By letters dated flarch 19, April 1, May 19, and September 24, 1981, and February 25, 1932, you submitted the design description of modifications required to meet Section III.G.3 of Appendix R to 10 CFR 50 for Big Rock Point. We have reviewed your submittal and find that additional information is required for us to complete our review. The information required was originally requested from you by letter dated February 20, 1981. Enclosure 1 to this letter indicates what information you have not supplied. Provide a complete response to the items indicated in Enclosure 1 within 60 days of receipt of this letter.
If your response is not complete at that time, you will be found in violation of 10 CFR 50.48(c)(5). Such a violation will be a continuing one and a civil penalty may be imposed for each day the violation continues.
- provides the staff's positions on certain features of your proposed design for alternative safe shutdown capability. Please respond to all items in Enclosure 2 within 60 days of receipt of this letter.
s While timely response to the items in Enclosure 2 is important; delays DfuksE(18/
beyond the requested 60 days will not be considered a violation of 10 CFR 50.4d(c)(5).
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David J. VandeWalle April 30,1982 is the Technical Evaluation Report (TER) prepared by Brookhaven National Laboratory for the NRC staff. This TER provides the background for the items discussed in Enclosures 1 and 2. provides information regarding our criteria for evaluating exemption requests from the requirements of Section III.G.2 of Appendix R.
Since this request relates to an issue and submittal specific to Big Rock Point. 010 clearance under P.L.96-511 is not required.
Sincerely, Original signed by G.C. Lainas, Assistant Director for Safety Assessment i
Division of Licensing Office of Nuclear Reactor Regulation
Enclosures:
1.
Request for Additional DISTRIBUTION:
Information per 10 CFR 50.48(c)(5)
Docket File 2.
Staff Position on Certain Issues of Plant Alternate ORB Rdg.
NRC PDR Safe Shutdown Design D. Eisenhut 3.
Technical Evaluation Report Local PDR by BHL H. Smith 4.
Exemption Criteria for T. Wambach Section III.G.2 of Appendix R (10)
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R. Ferguson (5)
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.Mr. David J. VandeWalle cc Mr. Paul A. Pe'ery, Secretary U. S. Environmental Protection Consumers Power Company Agency 212 West Michigan Avenue Federal Activities Branch Jackson, Michigan 49201 Region V Office ATTN: Regional Radiation Representative Judd L. Bacon, Esquire 230 South Dearborn Street Consumers Power Company Chicago, Illinois 60604 212 West Michigan Avenue Jackson, Michigan 49201 Peter B. Bloch,' Chairman Atomic Safety and Licensing Board Joseph Gallo, Esquire U. S. Nuclear Regulatory Commission Isham, Lincoln & Beale Washington, D. C.
'20555 1120 Connecticut Avenue Room 325 Dr. Oscar H. Paris Washington, D. C.
20036 Atomic Safety and Licensing Board U, S. Nuclear Regulatory Commission Peter W. Steketee, Esquire Wa.5ington, D. C.
20555 505 Peoples Building Grand Rapids, Michigan 49503 Mr. Frederick J. Shon Atomic Safety and Licensing Board Alan S. Rosenthal, Esq., Chairman U. S. Nuclear Regulatory Commission Atomic Safety & Licensing Appeal Board Washington, D. C.
20555 U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Big Rock Point Nuclear Power Plant ATTN: Mr. C. J. Hartman Mr. John O'Neill, II Plant Superintendent Route 2, Box 44' Charlevoix, Michigan 49720 Haple City, Michigan 49664 Mr. Jim E. Mills Route 2, Box,108C Route 2, Box 108C Charlevoix, Michigan 49720 Charlevoix, Michigan 49720 l
William J. Scanlon, Esquire Chairman 2034 Pauline Boulevard County Board of Supervisors Ann Arbor, Michigan 48103-l Charlevoix County
-Charlevoix, Michigan 49720 Resident Inspector
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Big Rock Point Plant Office of the Governor (2) c/o U.S. NRC l
Room 1 - Capitol Building RR #3, Box 600 t
Lansing, Michigan 48913 Charlevoix, Michigan 49720 Herbert Semmel Counsel for Christa Maria, et al.
Urban Law Institute Antioch School of Law 2633 16th. Street, NW Washington, D. C.
2C460 l
REQUEST FOR ADDITIONAL INFORMATION TO MEET SUBMITTAL REQUIREMENTS OF 10 CFR 50.48(c)(5)
BIG ROCK POINT PLANT DOCKET N0. 50-155 The licensee has not provided all the information requested for associated circuits of the shutdown systems which are in the fire area.
In order to resolve this item, the following information is needed. The requests are grouped into two sets depending on the approach that you select. You should respond to all the requests in one of the two sets for each area of concern.
FIRE AREA APPROACH For each fire area where an alternative or dedicated shutdown method, in accordance with Section III.G.3 of Appendix R is provided, the following information is required to demonstrate that associated circuits will not prevent operation or cause maloperation of the alternative or dedicated shutdown method:
a.
Provide a table that lists all the power cables in the fire area that connect to the same power supply of the alternative or dedicated shutdown method and the function of each power cable listed (i.e., power for RHR pump).
b.
Provide a table that lists all the cables in the fire area that were considered for possible spurious operation which would adversely affect shutdown and the functioU of each cable listed.
c.
Provide a table that lists 'all the cables in the fire area that share a common enclosure with circuits of the alternative or dedicated shutdown systems and the function of each cable listed.
d.
Show that fire-induced failures (hot shorts, open circuits or shorts to ground) of each of the cables listed in a, b, and c will
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not. prevent operation or cause maloperation of the alternative or dedicated shutdown method, e.
For each cable listed in a, b, and c where new electrical i' solation has been provided or modification to existing electrical isolation has been made, provide detailed electrical schematic drawings that show how each cable is isolated from the fire area.
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SYSTEMS APPROACH For each area where an alternative or dadicated shutdown method, in accordance with Section III.G.3 of Appendix R is provided, the following information is required to demonstrate that associated circuits will rot.
prevent operation or cause maloperation of the alternative or dedicated shutdown method:
a.
Describe the methodology used to assess the potential of associated circuic adversely affecting the alternative or dedicated shutdown.
The description of the methodology should include the methods used to identify the circuits which share a common power supply or a common enclosure with the alternative or dedicated shutdown system and the circuits whose spurious operation would affect shutdown.
Additionally, the description should include the methods used to identify if these circuits are associated circuits of concern due to their location in the fire area.
b.
Provide a table that lists all associated circuits of concern located in the fire area.
c.
Show that fire-induced failures (hot shorts, open circuits or shorts to ground) of each of the cables listed in b will not prevent operation or cause maloperation of the alternative or dedicated shutdown method.
d.
For each cable listed in b where new electrical isolation has been provided, provide detailed electrical schematic drawings that show how each cable is isolated from the fire area.
e.
Provide a location at the site or other offices where all the tables and drawings generated by this methodology approach for the associated circuits review may be audited to verify the information provided above.
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STAFF POSITION ON CERTAIN ISSUES OF PLANT ALTERNATE SAFE SHUTDOWN DESIGN BIG ROCK POINT PLANT DOCKET NO. 50-155 1.
Consumers Power Company's proposed method of shutdown includes repairing the power cables to the CRD pump which is used to provide primary coolant system makeup.
Section III.G of Appendix R requires all equipment needed to achieve and maintain hot shutdown to be free of fire damage.
Consumers Power must either request an exemption to the requirements of Appendix R with appropriate justification or provide alternative makeup capability.
2.
Consumers Power Company's proposed modification for alternative shutdown includes moving the controls for the emergency condenser from the control room to the auxiliary shutdown control station.
Thus, in the event of a control room fire or loss of offsite power (the emergency condenser is used for shutdown in event of a loss of offsite power), the operator would go to the auxiliary shutdown control station to operate the emergency condenser. However, in the event of a fire at the auxiliary shutdown control station or a fire involving the control cables for the emergency condenser coincident with a loss of offsite power, the operator could not achieve hot shutdown using the emergency condenser. The licensee has analyzed the probability of a fire at the auxiliary shutdown control station coincident with a loss of offsite power and concludes that the events are unlikely.
It is our position that since the emergency condenser is used for hot shutdown in the event of a loss of offsite power without considering a fire, control of the emergency condenser should be provided at both the control room and the auxiliary control station.
The licensee shou,ld propose modifications to meet our position.
3.
The review of SEP Topic VII-3, " Systems Required for Safe Shutdown" indicated that the use of the emergency condenser was limited to 36 hour4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />, whenever the fire water system is used for emergency condenser makeup. Based on the SEP review, it is our position that the licensee
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provide the capability to achieve cold shutdown with limitdd use of the emergency condenser as defined in the SEP revi,ew or present just.ification that corrosion will not limit usage of the emergency condenser for a l
period of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
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2-4.
The licensee indicated that material for repairs-would not be stored onsite because the materials are readily available offsite.
Appendix R,Section III.L, Paragraph 5 states, " Materials for such repairs shall be readily available onsite..." The licensee must provide a commit-ment to store the materials needed for repairs onsite.
5.
The licensee indicated by letter dated May 19, 1981, that fire damage and spurious closing of the emergency condenser inlet valves would be prevented by removing operating power from these valves.
It is our understanding that the licensee now wishes to leave the power to these valves and provide separation of the power cables to prevent fire damage to the redundant cables.
The licensee should verify that the separation of the redundant cables to the emergency condenser inlet valves meets the requirements of Section III.G.2 of Appendix R.
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BROCKHAVEN NATIONAL LABORATORY ASSOCIATED UNIVERSITIES, INC.
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J Upton. New York 11973 Department of Nuclear EnerOy (516) 345e 282-2362 October 28, 1981 Mr. Vincent Panciera Auxiliary Systems Branch i
U.S. Nuclear Regulatory Commission 4
Washington, D.C.
20555
Dear Vince:
Enclosed is the Brookhaven National Laboratory report of the post-fire shutdown capability for the Big Reck Point Plant.
The licensee has addressed all the areas of concern outlined in the NRC february 20, 1981 letter to all licensees on this subject.
The methods chosen by Big Rock Point and outlined in their submittals are adequate and will. result in an alternate safe shutdown capability in case of fire in the plant, provided they have 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to reach cold shutdown.
- However, based on a NRC letter dated May 13, 1981, this plant has only 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> to reach cold shutdown due to corrosion.
This new time frame may negate some of the items that a,re acceptable when 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> are available to reach cold shutdosn.
Respectfully yours, Edward A. MacDougall Risk Assessment & Engineering Analysis EAM:VL:sd enclosure cc.:
R. Cerbone A. Coppola R. Hall W. Kato V. Lettieri W. Luckas R. Smith
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POST FIRE SHUTDOWN CAPABIllTY Big Rock Point Plant Consumers Power Company (Docket No. 50-155)
BNL Reviewer - V. Lettieri Report Date - October 28, 1981
1.0 INTRODUCTION
1.1 Background
In a letter dated March 19, 1981 and additional submittals dated 4/1/81, 5/19/81, and 9/24/81, Big Rock Point has described their proposed mod-ifications to meet the requirements of Appendix R to 10CFR 50.48 and provided responses to the questions raised inf the NRC Generic Letter 18-12 dated Febru-o l
ary 20, 1981.
In addition to written submittals a conference call was held on July 8,1981 and a neeting was held at the plant on July 28, 1981.
1.2 Fire Protection SER Position The SER of April 4,1979 described in Items 5.1 Containment, 5.3 Control Room, 5.4 Electrical Equipment Room, 5.5 Condensate Pump Room, 5.7 Exterior Cable Penetration Room, 5.8 Auxiliary Boiler Room, and 5.10 Turbine-Generator Building, various difficulties which required the licensee to develop a post-fire shutdown capabilitiy.
.1. 3 Plant Description Big Rock Point is a Boiling Water Reactor with'a net megawatt electric capacity of 71.
The reactor supplier was General Electric.
The Architect /
Engineer and Builder was Bechtel.
This is a single-unit plant that started commercial operation in December 1965.
2.0 REVIEW AND EVALUATION 2.1 Section III.G - Fire Protection of Safe Shutdown Capability 2.1.1 Post Fire Safe Shutdown System The licensee will utilize the following systems to bring this plant to a safe cold shutdown condition:
a) Emergency Condenser b) Control Rod Drive Pumps c) Shutdown Cooling System d) Fire Water Pumps e) Main Steam System-Repairs will be made if necessary to replace the power feeds to the pump for shutdown' cooling.
The' lice'nsee will have on site a prepared cable to insert for power to the control rod drive puaps for reactor coolant makeup. By anaysis, the licensee'has 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> to install this prepared cable, see item 2.2.1.b of this report.
2.1.2 Fire Protection Provided The licensee has not addressed the implementation of any additional fire protection beyond what was covered by the April 4,1979 SER.
2.1.3 Safe Shutdown - Fire Areas The licensee has chosen to construct an auxiliary shutdown control sta-tion in the Core Spray Equipment Room.
The power supply and supporting equip-ment for the auxiliary shutdown control station will be located in the stair-way adjacent to the Core Spray Equipment Room.
A fire protection engineering review has not been performed at Brook-haven National Laboratory.
The fire protection engineering review will be conducted by the NRC staf f.
2.2 Section Ill.L - Alternate and Dedicated Shutdown Capability - Compliance 2.2.1 Performance Goals - Analysis a) Reactivity Control - Reactivity control for both hot and cold shut-down will be provided by the control rods.
b) Reactor Coolant Make-up - Make up to the primary system will be provided by Control Rod Drive Pump #1 for both hot and cold shutdown.
By analysis provided in the September 24, 1981 submittal, response to question 2 on page 3, the licensee will be able to provide power to this pump, given a fire and loss of off-site power, within 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br />.
The licensee's analysis states that there will be a't least 9 hours1.041667e-4 days <br />0.0025 hours <br />1.488095e-5 weeks <br />3.4245e-6 months <br /> before make up to the primary system is required, c) Reactor Decay Heat Removal - Decay heat shall be removed through the use of the Emergency Condenser for Hot Shutdown.
For cold shutdown, the Shutdown Cooling System kill be used to remove decay heat.
d) Prtcess Monitoring - The licensee shall display drum level (reactor water level) and reactor coolant pressure.
Reactor coolant tem-perature will be determined by use of a chart, assuming saturated steam conditions, as agreed at the July 28, 1981 meeting at the i
plant. Big Rock Point does not utilize a suppression poolrinstead its safety and relief valves empty into the containment.
The Em-ergency Condenser shell side water level will be annunciated at both the control room and the auxiliary shutdown control station. A flow switch will be provided in the fire water makeup line to the em-ergency condenser.
This flow switch will actuate a light located at I
the auxiliary shutdown control station when flow is detected.
The water supplies will not be coming froq, tanks, but instead from Lake Michigan through the use of the fire pumps.
l e) Support Functions ~- The licensee stated at the July 28, 1981 meeting ~
i and in the March 19, 1981 submittal that after a fire the support functions shall still be available.
1 f) The licensee has stated they can achieve cold shutdown conditions within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and maintain cold shutdown conditions thereafter, with or without offsite power.
2.2.2 Manual Operations and Loss of Off-Site Power The procedures required to take the plant to hot shutdown via the aux-iliary shutdown control station in the event of a fire have yet to be pre-pared.
The licensee states these procedures will be finalized when the de-tailed design documents are completed and will be implemented, including a.p-propriate training, prior to operation of the facility with the completed fire.
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protection modifications declared operable.
Manual operations consist of opening the fire water make-up valve and operating transfer switches.
The licensee states in the May 19, 1981 submittal that there is sufficient man-power available for safe shutdown.
The difficulty with the loss of off-site power and a fire is that this will require use of the fire water pumps to make up to the Emergency Condenser.
From NRC's letter dated May 13, 1981, LS05-81-024, subject: Big Rock Point-SEP Topics V-10.B, RHR Reliability, V-11.B, RHR Interlock Requirements and VII-3, Systems Required for Safe Shut-down (Safe Shutdown Systems Report):
" Based on the potential for energency condenser materials corrosion, tht operating procedures for the big Rock Point plant should be modified to direct the operator to cooldown and depressurize the reactor plant, within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />, to either 1) SCS initiation pressure (if the SCS is operable), or 2) approximately 100 psig (if the SCS is not operable),
whenever the fire water system is used for emergency condenser makeup.
Af ter the appropriate conditions above are achieved, the plant should be expeditiously placed in a cold shutdown condition using the SCS or the RDS, CS, and containaent cooling systems if indications of emergency condenser tube leakage develop."
2.2.3 Repairs Repairs will be made on the Shutdown Cooling System (SCS) in the form of repairs to the power feeds for the reactor cooling water pump and or a shut-down pump i f required.
The licensee's May 19, 1981 submittal in response to Staff Position number'8L states in part:
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"In the event fire damage precludes use of a reactor cooling water pump or a shutdown pump in its normal fashion, then one motor of each ty'pe of pump will be disconnected from its damaged feeder and connected to cir-cuit breaker connected to a power feed cable permanently connected through containment via the equipment lock.
The exterior end of the feejer cable would then be connected to the emergency generator or to a
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480V source connected to" present 400V station power source in the sub-station."
"The emergency condenser is capable of supporting the hot shutdown oper-ation provided make-up water from the fire system to the shell of the condenser is available.
Shutdown cooling can be provided within two days considering the common availability of electrical cable and trans- __
1 formers (from within consumers Power Company and/or from ccmmercial electrical equipment and materials suppliers) as needed to icstall a temporary 480V power source connected to the power feeder through con-tainment for the shutdown cooling system.
Since there are many options for providing this emergency power source, the most suitable and most expeditious would be selected at the time of this' contingency, if it ever occurs.
Because of their ready availability, materials and-equip-ment will not be obtained and stored in advance."
The licensee feels very strongly that the materials required for these repairs need not be kept on site, and this position was discussed with the licensee at the visit to the plant on July 28, 1981.
2.2.4 Associated Circuits and Isolation Associated circuits have been addressed only for the inlet emergency condenser valves.
All associated circuits need to be listed and evaluated.
The licensee's design concept of running centrol power cables separate from the non-power control cables is satisactory.
Also, the NEMA rated manual power transfer switches are satisfactory provided the current and voltage rat-ing match the motor to be used.
A seismic evaluation of isolation _ devices could be required when the de-tailed design of all isolation devices has been made.
No attempt has been made to perform this evaluation at this time since we are reviewing design concepts only.
3.0 CONCLUSION
AND RECOMMENDATIONS 3.1 Areas of Compliance With the exceptions listed below in Section 3.2 af this report, Big Rock Point meets the intent of Appendix R,10CFR part 50, for performance goals.
See item 2.2.1 of this report for an analysis of the performance goals.
The licensee states in the April 1, 1981 submittal that "the modifications planned will insure the plant's ability to maintain a hot shutdown condition for at least 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, with or without offsite power, following a fire in any of the defined fire areas."
Recommendations 3.2 a) An analysis which demonstrates that the use of the fire. pumps will not jeopardize the fire fighting capability and will provide suf-ficient water for safe shutdown was presented in the December 8, 1978 submittal to the NRC.
It is recommended, based-on this prev-
'ious analysis, that the fire pumps be%used for the alternate shut-down capability.
b)
It'is recommended, ba' sed on the analysis presented in the' September '
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24, 1981 submittal, that the licensee be allowed to connect a pre-constructed power feed cable for the operation of the control rod drive pumps.
See item 2.2.1.b of this report for additional information.
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c) Open' item - The licensee does not plan to have the materials re-quired for repairs on site, see item 2.2.3 of this report for ad-ditional information.
It is recommended that the licensee be.re-quired to have the materials on site for all repairs.
d) Open item - The licensee's submittals do not address the concern presented in the May 13, 1981 letter from the NRC about corrosion causing failure of the Emergency Condenser after 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> (see item 2.2.2 of this report for additional information).
The licensee should review the Alternate Shutdown capability and demonstrate cold shutdown can be reached within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> given any fire.
e) Open item - Associated circuits and their isolation means' have been addressed only for the inlet Emergency Condenser valves.
All as-l sociated circuits need to be listed and evaluated.
f) Open item - A fire in the Auxiliary Shutdown Control Station and a coincident loss of offsite power was analyzed by the licensee in the September 24, 1981 submittal, question #4.
This analysis is based on a Probabilistic Risk Assessment which we did not evaluate.
It is our opinion that the licensee should use existing power sources with isolation devices in conjunction with the new power sources. The licensee plans to cut all existing power leads, once the new sources are installed to eliminate problems with isolation of safe shutdown circuits.
g) Open item - The NEMA rated manual power transfer switch is satisfac-tory provided the current and voltage rating itch the motors to be used.
h) Open item - New procedures for alternative shutdown methods and re-pair methods have not as yet been written.
Then they have been sub-mitted, they should be reviewed by NRC staff for manpower require-
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ments, manual operation, and other NRC general procedure require-ments.
The review summarized in this report has concentrated on the post fire safe shutdown systems and capabilities of the Big Rock Point plant.
Other as-pects of fire protection (such as adequacy of barriers, suppression systems, separation between cabling, etc.) have not been evaluated in this report.
e CRITERIA FOR EVAL'UATItiG
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EXEMPT 10flS TO SECTI0t1 III G 0F APPEtJOIX R j
0F 10 CFR PART 50 Paragraph 50.48 Fire Protection of 10 CFR Part 50 requires that all nuclear power plants licensed prior to January 1,1979 satisfy the requirements of Section III.G of Appendix R to 10 CFR Part 50.
It also requires that alternative fire protection configurations,.
previously approved by an SER be reexamined for compliante with the requirements of Section III.G.Section III.G is related to fire protection features for ensuring that systems and associated circuits used to achieve and maintain safe shutdown are free of fire damage.
Fire protsction configurations must eithe.r meet the specific require-ments of Section III.G or an alternative fire protection configuration '
must be justified by a fire hazard analysis.
The general criteria for accepting an alternative fire protection configur-ations are the following:
The alternative assures that one train of equipment necessary to achieve hot shutdown from either the control room or emergency control stations is free of fire damage.
The alternative assures that fire damage to at least one train of equipment necessary to achieve cold shutdown is limited such that it can be repaired within a reasonable time (minor repairs with components stored on-site).
Fire retardant coatings are not used as fire barriers.
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Modifications required to meet Section III.G would not enhance fire protection safety above that provided by either existing or proposed alternatives.
Modifications required to meet Section III.G would be detrimental to overall faci.11ty safety.
Because of the broad spectrum of potential configurations for which exemptions may be, requested, specific criteria that account for all of the parameters that are important to fire protection and consistent with safety requirements of all plant-unique configurations have not been developed.
However, our evaluations of deviations from these require-ments in our grevious reviews'and in the request's for III.G exemptions received to date have identified some recurring configurations for which specific criteria have been developed.
a
,Section III.G.2 accepts three methods of fire protection.
A passive 3-hour fire barrier should be used where possible.
Where a fixed barrier cannot be installed, an automatic suppression system in combination with a fire barrier or a separation distance free of combustibles is used if the configurations of systems to be protected and in-situ combustibles are such that there is reasonable assurance that the protected systems will survive.
If this latter condition is not met, alternative shutdown capa-bility is required and a fixed suppression system installed in the fire area of concern, if it contains a large concentration of cables.
It is essential to remember that these alternative requirements are not deemed to be equivalent.
However, they provide adequate protection for those configurations in which they are accepted.
When the fire protection features of each fire area are eva'uated, the whole system of such features must be kept in perspective. The defense-in-depth principle of fire protection programs is aimed at achieving an adequate balance between the different features. Strengthening any one can compensate in some meastre for weaknesses, known or unknown in others.
The adequacy of fire protection for any particular plant safety system or area is determined by analysis of the effects of postulated fire relative to maintaining the ability to safely shutdown the plant and minimize radio-active releases to the environment in the event of a fire.
During thes,e evaluations it is necessary to consider the two-edged nature of fire protection features recognized in General Design Criterion 3 namely, fire protection should be provided consistent with other safety considerations.
An evaluation must be made for each fire area for which an exemption is requested.
During these evaluations, the staff considers the following parameters:
'A.
Area Description
- walls, floor, and ceiling construction ceiling height room volume ventilation
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congestion B.
Safe Shutdown Capability number of redundant systems in area whether or not system or equiment is. required for hot shutdown type of equipment / cables involved repair time for ~ cold shutdown equipant within this area separation between redundant components and in-situ concentration of combustibles alternative shutdown capability
C.
Fire Hazard Analysis type and configuration of combustibles in area quantity of combustibles ease of ignition and propagation heat release rate potential transient and installed combustibles suppression damage to equipment whether the area is continuously manned traffic through the area accessibility of the area D.
Fire Protection Existing or Committed fire detection systems fire extinguishing systems hoge station / extinguisher radiant heat shields A specific description of the fire protection features of the configuration is required to justify the compensating features of the alternative. Low fire loading is not a sufficient basis for granting an exemption in areas where there are cables.
I If necessary, a team of. experts, including a fire protection engineer, will visit the site to determine the existing circumstances. This visual inspection is also considered in the review process.
I The majority of the III.G exemption requests received to date are being denied because they lack specificity.
Licensees have not identified the extent of the exemption requested, have not provided a technical basis For the request and/or have not provided a specific description of the alternative.
We expect to receive requests for exemption.of.the following nature:
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1.
Fix'ed fire barriers less than 3-hour rating.
2.
Fire barrier without an automatic fire suppression system.
3.
Less than 20 feet separation of cables with fire propagation retardants (e.g., coatings, blankets, covered trays) and an automatic suppression system.
4.
For large open areas with few components to be protected and few in-situ combustibles, no automatic suppression system with separation as in Item 3 above.
5.
No' fixed suppression in the contr'ol room.
6.
No fixed suppression in areas without a large concentration of cables for which alternative shutdown capability has been provided.
Our fire research test program is conducting tests to provide information that will be useful to determine the boundary of acceptable conditions for fire protection configurations which do not include a fire rated barrier.
Based on deviations recently approved, specific criteria for certain recurring configurations are as follows:
Fire Barrier Less than Three Hours This barrier is a wall, floor, ceiling or an enclosure which separates one fire area from another.
Exemptions may be granted for a lower rath j (e.g., one hour or two'hou's) r where the fire loading is no more than 1/2 of the barrier rating. The fire rating of the barrier shall be no less than one hour.
Exemptions may be granted for a fixed barrier with a lower fix rating supplemented by a water curtain.
An Automatic Suppression System With Either One Hour Fire Barrier or 20-Foot Separation This barrier is an enclosure which separates those portions of one division which are within 20 feet of the redundant division.
The suppressart may be water or gas.
Exemptions may be granted for configurations of redundant systems which l
'have compensating features.
For example:
A.
Separation distances less than 20 feet may be deemed acceptable where:
1.
Fire propagation retardants (i.e., cable coatings, covere.d trays, l
conduits, or mineral wool blankets) assure that fire propagation l
through in-situ combustibles will not occur or will be delayed sufficiently to ensure adequate time for detection and suppression.
2.
Distance above a floor level exposure fire and below ceiling assures that redundant systems will not be simultaneously subject to an unacceptable temperature or heat flux.
B.
The ommission of an automatic suppression system may be deemed acceptable where:
1.
Distance above a floor level exposure fire and below ceiling assures I
that redundant systems will not be simultaneously subject to an l
unacceptable temperature or heat flux.
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.2.
The fire area is required to be manned continuously by the provisions in the Technical Specifications.
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