ML20052C821
| ML20052C821 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 04/08/1982 |
| From: | Novak T Office of Nuclear Reactor Regulation |
| To: | William Jones OMAHA PUBLIC POWER DISTRICT |
| References | |
| GL-81-12, NUDOCS 8205050576 | |
| Download: ML20052C821 (32) | |
Text
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3 g5 /qWOiO Docket No. 50-285 APR 8 1982 Mr. W. C. Jones
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f"\\ @ I 'N Division Manager, Production f
q, Operations Omaha Public Power District V-s
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Omaha, Nebraska 68102
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Dear Mr. Jones:
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SUBJECT:
FIRE PROTECTION RULE-10 CFR 50.48(c)(5) ALTERNATIVES f,
SAFE SHUTDOWN-SECTION III.G.3 0F APPENDIX R TO 10
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CFR 50, FORT CALHOUN NUCLEAR POWER STATION.
The Fire Protection Rule (10 CFR 50.48 and Appendix R to 10 CFR 50) became 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.
You have addressed the design description of modifications required to meet Section III.G.3 of Appendix R to 10 CFR 50 in several docu-These are the " Alternate Shutdown Capability, ments and letters.
Final Design Description" dated October 12,1979(revisedJanuaryY980),
" Alternate Shutdown Capability, Cold Shutdown Phase" dated November 15, 1979 (revised March 1980), and submittals dated October 12, 1979 and March 27, 1981. Additional information and clarification was obtained through telephone conferences of January 30 and August 19, 1981. We have reviewed your submittals and we have prepared a Safety Eval-uation Report (enclosed). The Safety Evaluation Report contains three open items.
Two open items relate to features of your alternative safe shutdown that we find deficient. Our position is that (a) a source range flux monitor independent of the cable spreading room and control room should be installed on the new instrument rack, and (b) modifications must be made to the plant such that no wiring changes or pulling of fusas are necessary to achieve and maintain hot standby.
Please provide your response within 60 days of receipt of this letter in regard to these two open items.
The third open item, which must be further addressed, is in regard to our concerns that there could be non-safety related circuits that are associated with the alternative safe shutdown circuits that would fail due to a fire and affect safe shutdown by short circuits or grounds, t
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- n' is g In regard to this open item, you should address the concern that there could be non-safety related circuits that are associated with the alternative safe shutdown circuits that could fail due to a fire and affect safe shutdown by short circuits or grounds. The infor-mation required for open item tnree was originally requested ffom you by letter dated February 20, 1981.
Please provide a complete response to open item three within 60 days of receipt of this letter.
If your response to open item three is not complete at that time, you will be found in violation of 10 CFR 50.48(c)S.
Such a vio' ation would be a continuing one and a civil penalty may be imposec for each day the violation continues. provides a rewording of the request for information in-cluded with generic letter 81-12. This rewording is the result of meetings with representative licensees who felt that clarification of the request would help expedite responses.
It does not include any new requests and, therefore, will not adversely affect licensees' ability to respond to generic letter 81-12. provides information regarding our criteria for eval-uating exemption requests from the requirements of Section III.G.2 of Appendix R.
This enclosure is provided for your information.
If you have any questions regarding this matter, contact your NRC project manager. The reporting and/or recordkeeping requirements contained in this letter affect fewer than ten licensees, there-fore OMB Clearance is not required under P.l.96-511.
Sincerely, O d gine.! si. p u w Thomas M. Novak, Assistant Director
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for Operating Reactors, Division of Licensing
Enclosures:
As stated DISTRIBUTION Mcket File l
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Omaha Public Power District cc:
Marilyn T. Shaw, Esq.
LeBoeuf, Lamb, Leiby & MacRae 1333 New Hampshire Avenue, N.W.
Washington, D. C.
20036 Mr. Jack Jensen Chairman, Washington County Board of Supervisors
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Blair, Nebraska ~68023 U.S. Environmental Protection Agency Region VII ATTN: Regional Radiation Representative 324 East lith Street Xansas City, Missouri 64106 Mr. Frank Gibson W. Dale Clark Library 215 South 15th Street Omaha, Nebraska 68102 Alan H. Kirshen, Esq.
Fe11 man, Ramsey & Kirshen 1166 Woodmen Tower Omaha, Nebraska 68102 Mr. Larry Yandel.1 U.S.N.R.C. Resident Inspector P. O. Box 309 Fort Calhoun, Nebraska 68023 Mr. Charles B. Brinkman Manager - Washington Nuclear Operations C-E Power Systems Co'mbustion Engineering, Inc.
4853 Cordell Avenue, Suite A-1 Bethesda, Maryland 20014 Regional Administrator Nuclear Regulatory Commission, Region IV Office of Executive Director for Operations 611 Ryan Plaza Drive Suite 1000 Arlington, Texas 76011 O
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UNITED STATES o
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- .rh py, e WASHING To N, o. C. 20555 FORT CALHOUN NUCLEAR POWER STATION SAFETY EVALUATION REPORT 10 CFR 50, APPENDIX R, ITEMS III.G AND III.L INTRODUCTION
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The Licensee has addressed fire protection for the Fort Calhoun Nuclear Power Station with respect to Title 10 o f the Code of Federal Regulations, Part 50, Appendix R, Paragraphs III.G.and III.L in several documents and Letters.
These are'the " Alter-nate Shutdown Capability, Final Design Description" dated
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October 12, 1979 (revised January 1980), " Alternate Shutdown Capability, Cold Shutdown Phase" dated November 15, 1979 (revised March 1980), and submittats dated October 12, 1979 and March 27, 1981.
Additional information and clarification was obtained through telephone conferences on Jequary 30 and August 19, 1981.
The Licensee described a method of fire related shutdown without the use of any new equipment or additional fire barriers.
Alternate shutdown control was f rom the auxiliary feedwater panel.
I Our Safety Evaluation Report for the Fort Calhoun Nuclear Power Station dated August 23, 1978 states that the l'icensee has agreed to-provide alternate shutdown capability independent of cabling in the cable spreading room and the control room to preserve safe shu~tdown capability in the event of a fire in these areas.
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o The Licensee's submittal of October 12, 1979 d'etails the systems required for alternate shutdown.
These systems are reactivity control, reactor coolant makeup, reactor coolant system pressure control, decay heat removal, process monitoring and necessary supporting systems.
An aitternate shutdown panet wilL be located adjacent to the present auxiliary feedwater panel in the electrical penetration room to contain such additional con-trol and instrumentation as ne,eded to maintain hot shutdown.
The licensee's submittal of March 27, 1981 contained-a cable separation analysis which demonstrates that alL safety related cables meet.the requi rements of Appendi x R.
We have reviewed this analysis and find it a c c e p t a b t'e.
The control and instrument isolation devices are L o c'k o u t relays and manual transfer switches.
Operation of these devices at the proposed voltages has been reviewed and discussed with the Licensee during our conference call of August 19', 1981 and found acceptabLt.
The Licensee has elected to bring the plant to a hot shutdown sta.tus and then to a cold shutdown condition by relying on existing equipment.
The major equipment used for the ' alter nate mode o'f shutdown in the event of fire is summarized as fotlows:
G
A.
Hot Standby l
Initial Rea c t i vi t y Control - reactor protection system, (control rods)
RCS Inventory Control - charging pump and concentrated boric acid storage tank Emergency A.
C. Power'- diesel generator l
Emergency D.
C.
Power - 125 VDC Battery
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Secondary Side Inventory, Control' - auxiliary feedwater storage tank and auxiliary f eedwater pumps
'RCS Pressure Control - pressurizer heaters and spray Secondary Side Pressure Control - safety relief valves B.
Cold Shutdown For cold shutdown the same equipment is used as for hot standby a's welL as the fotLowing equipment:
Auxiliary Pressurizer Spray Low Pressure Safety Injection System Component Cooling Water System Raw Water Systems Most of the equipment and controls necessary to monitor and sequence the hot shutdown and then the cold shutdown func-tions are already available from areas outside the con-trot. room.
Indicators for the primary hot leg and cold leg temperature, pressurizer water level, and the volume control tank water Level witL be added to the shutdown panel.
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Controls and instrumentation wilL be located'on the alter-nate shutdown panel which wilL be i nstalled adjacent to the auxiliary feedwater panet in the electrical penetration Toom.
III.L - Compliance Performance Goals The performance goals for post fire safe shutdown wilL be met using existing mechanical systems and equipment as outlined above.
The control of these functions is already available from outside the control room.
This includes manual positioning of valves.
Where necessary, additional controls wilL be pro-vided on the alternate shutdown panet to augment the process
. monitoring function.
The only support systems required to preserve shutdown capability i
are ;.C and'DC power sources and the associated distribution systems.
Primary system pressure wilL be maintained by removing sufficient decay heat via the steam generator safety valves and auxiliary f eedwate r syst em.
If the reactor residual heat decays with time to where it will not maintain reactor pressure within the limits, a bank r,f pressurizer heaters can be pla ced in : servi ce.
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and power for the back-up pressurizer heaters are supplied by a motor control center near the auxiliary feedwater panet and they can be operated from there.
[The. Licensee states that cir-cuit wires at the MCC would be locally isolated by physically removing or disconnecting wires.
This is not acceptable.
We j
t reouire the Licensee to install at L necessary equipment and 1
i devices such that no wiring changes or putLing of fuses is j
necessary to go to and maintain hot standby].
'The direct reading instrumentation for hot shutdown consists of 1
the fotLowing parameters.
1.
Pressurizer Pressure 2.
Pressurizer Level 3.
Reactor Coolant Hot Leg and Cold Leg Temperatures 4.
Steam Generator Level 5.
Volume Control *.ank Level 6.
Auxiliary Feedwater Storage Tank Level The Licensee proposed to use batch sampling for the concentration of boron as a means to determine the shutdown margin of the reactor.
[We do not agree with this propsal and require that the Licensee add a source range flux monitor to the new instrumenta-tion rack which witL provide a direct reading as required in Appendix R.]
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Procedures and Personnel Requirements Licensee has. reviewed the manpower needs to perform the The shutdown and has confirmed that the tasks to be performed immediately can be performed with existing on-shift personnet and sufficient manpower for augmentation is available for tran-sition to long-term shutdown /cooldown.
The loss of off-site is one of the design criteria of the Licensee's post fire power shutdown capability.
Its Loss, therefore, is considered in the manpower requirements.
Repairs The Licensee's submittal of March 27, 1981 states that the repair have been developed and repair materials are readily procedures available in the Fort Calhoun storeroom.
ISE should confirm that atL materials required for repairs are properly tagged and stored in the storeroom.
Associated Circuits The Licensee has stated that damage to associated circuits wilL not prevent proper operation of shutdown equipment and has pro-vi'ded details of typical isolation devices for control'and instrumentation circuits.
These are acceptable for the voltages indicated.
[The Licensee has not evaluated the effects of non-related circuits associated with alternate safe shutdown safety circuits.
We require the Licensee to provide the results of this description of alL proposed modifications.]
evaluation as welL as a O
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Conclusions Based on our review we conclude that the Fort Calhoun design meets the requi rements of Appendix R to 10 CFR 50, Items III.G and III.L with respect to safe shutdown in the event of a fi e,
with the fotLowing exceptions:
1.
A source range flux monitor should be installed on the new instrument rack.
2.
The Licensee should address the concern that there could be no.n-safety related circuits that are associated with the alternative safe shutdown circuits that would fait due to a fire and affect safe shutdown by short circuits or grounds.
3.
The licenseec must make modifications to the plant such that' no wiring changes or putLing of fuses is necessary to achieve and maintain hot standby, in accordance with Appendix R.
With the exception of the three items above.and I&E verification of atL required materials for repairs being in the storeroom,,the Fort Calhoun design meets the requirements of Paragraphs III.G and III.L of Appendix R.
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CLARIFICATION OF GEllERIC LETTER generic letter 81-12 was forwarded to all reactor licensees On February 20, 1981, The letter restated the require-with plants licensed prior to January 1,1979.
ment of Section 50.48 to 10 CFR Part 50 that each licensee would be required to reassess areas of the plant where cables or equipment including associated non-safety circuits of redundant trains of systems necessary to achieve and maintain hot shutdown conditions are located to determine whether the require 2
Additional 1y, ments.of Section III.G.2 of Appendix R to 10 CFR 50 were sa.tisfied.
~ and Enclosure 2 of the generic letter requested additional h tdown
.infomation concsrning those areas of the plant requiring alternative s u Section 8 of Enclosure 1 requested information for the systems, capability.
equipment and procedures of alternative shutdown capability and Enclos
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defined associated circuits and requested information concerning associated ci'rcuits for those areas requiring alternative shutdown.
In our review cf licensee submittals and meetings with licen' sees, it has become apparent that the request for information should be clarified since a lack of clarity could result in the submission of either insufficient or e,xcessive Thus, the staff has rewritten Section 8 of Enclosure 1 and information.
' of the February 20,1981. generic letter. Addi,tionally, further clarification of the definition of associated circuits has been provided to aid in the reassessments to determine compliance with the requirements of In developing this= rewrite we have Sections III.G.2 and III.G.3 of Appendix R.
The enclosed considered the-coment of the Nuclear Utility Fire Protection Group.
rewrite of the Enclosures contains no new requirements but merely attempts to clarify the request for additional information.
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d 2-1 Licensees who have not responded to the February 20, 1981 generic letter, r.ay choose to respond to the enclosed request for information.
Since the enclosed request for information is not new, but merely clarification of our, previous letter, responding to it should not delay any submittals. in progress that are. based upon February 20, 1981 letter. Licensees whose response to the February 20, 1981 letter, has been found incomplete resulting in staff identifications of a major unresolved item (14e., associated circuits),
may choose to respond to pertinent sections of the enclosed request for infor-mation in order to close open~ items (i.e., open item for.asscc'iated circuits.
use rewrite of Enclosure 2).
If additional clarification is needed, please contact the staff Project Manager for your plant.
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REWRITE OF SECTION 8 REQUEST FOR ADDITION The following is a rewrite of the staff's request for additional informat
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f concerning design modification to meet the requirenents of Section I Tt.c following contains no new requests but is merely a rew Appendix P..
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20,'1981 generic letter.
Section 8 of Enclosure 1 of the February Ide'ntify. those areas of the plant that will not meet the requirem k.,
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of Appendix R and, thus alter' native shutdown will be p Section III.G.2 ill'be
', or an exemption from the requirements of Section III.G.2 Additionally provide a statement that all other areas of the orovided.
are or will be in compliance with Section III.G.2 of Appendix R.
For each of those fire areas of the plant requiring an alternat for systen(s) provide a complete set of responses to the followin each fire area:
List the system (s) or portions thereof used to provide the shutdo a.
capability with the loss of offsite power.
For those systems identified in '.'la" for which alternative or b.
shutdowncapabilitymustbeprovided,listtheequipbentand of the normal shutdown system in the fire area and.identif9 9
of the circuits of the normal shutdown system in the fire are Describe equ'ipment, control of what components and instrumentation h tdowa the system (s) or portions thereof used to provide the alterna capabOity for the fire area and provide a table that lists and components of the alternative shutdown system for the fire
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e For each alternative system identify the function of.the new Identify the location (fire zone) of the circuits being provided.
alternative shutdown equipment and/or circuits that bypass the fire area and verify that the alternative' shutdown equipment and/or circuit are separated from the fire area in accordance with Secticn III.G.2 Provide drawings of the alternative shutdown system (s) which hig c.
connections to the normal shutdown systems (P& ids for piping Showthe' electrical elementary wiring diagrams of electrical cabling).
location of all breakers for power cables, and isolation devices f t
control and instrumentation circuits for the alternative shutdown s for that fire area.
Verify that changes 'to safety systems will not degrade safety systems;'
d.
(e.g., new isolation switches and control switches should meet design criteria and standards in the FSAR for electrical' equipment in the system that the switch is to be installed; cabinets that the switches are to be mounted in should also meet the same criteria (FSAR) as other s'afety related cabinets and panels; to avoid inadvertent is~olation from the control room, the isolation switches should be keylocked or alamed in the control ioom if in the " local" or " isolated" position; periodic checks should be made to verify that the switch is in the proper pos normal, operation; and a single transfer switch or other new devi not be a source of a failure which causes ' loss of reounoant safe systems).
Verify that licensee procedures have been or will be develo' ped which desc er Provide a summary tasks to be perfomed to effect the shutdown. method.
,of these procedures 6utlining operator actions.
Verify that the manpower required to perform the shutdown functions using f..
the procedures of es as well as to provide fire brigade members to fight the fire is available as required by the fire brigade technical speci-fications.
9.. Provide a commitment to perform adequate acceptance. tests of the alter-native shutdown capability. These' tests shbu-ld verify that:
equipment operates from the local control station when the. transfer or isolation
'j switch is placed in' tile'" local". position and th'at-the equipment.cannot operated,from the control room; and that equipment operates from'th control room but cannot be operated. at the local control station when
.the transfer isolation switch' is in the " remote" position.
Provide Technical Specifications of the surveillance requirements and h.
limiting conditions for operation for that equipment not 'already '
covered by existing Technical Specifications.
For. example, if new.
isolatiori and control switches are added to a shutdown system, the existing Technical' Specification surveillance requirements should
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be supplemented to verify system / equipment functions fro i
f shutdown station at testing intervals consistent with the guidel Credit may be taken for other existing Regulatory Guide 1.22 and IEEE 338.
j tests using group overlap test concepts.
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For new equipment comprising the alternative shutdown capability, verify that the systems available are adequate to perform the necessary shut-down function.
The functions required should be based on previous analyses, if possible (e.g., in the FSAR), such as a loss of normal ac
.The equipme'nt required power or shutdown on Group 1 isola, tion (BWR).
for the alternative capability should be the same or equivalent to that - -
relied on in the above analysis.
- j.. Verify. that repair procedures for cold shutdown systems are developed
, and material for repairs is maintained on site.
Provide a summari of these procedures and a: list of the material needed for repairs'.
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SAFE SHUTDOWi< CAPABILITY The following discusses the requirements for. protecting redundant and/or alternative equipment needed for safe shutdown in the event of a fire. The requirements of Appendix R address hot shutdown equipment which must b[
free of fire damage.
The fo110 wing r.equirements also apply to cold s,hutdown equipment if the licensee elects to demonstrate that the.equipaent.is to be, free of fire. damage.
AppendE R does allow.rejairable damage to cold shutdown eautoment..
Us'ing the requirements of Sections III.G and III.L of kppendix R, the Sa'pS bility'to achieve hot shutdown must exist given a fire in any area of the plant in conjunction with a loss of offsite power for.72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
Section III.G of Appendix R provides four methods for ensuring that th'e hot shutdown capa-bility is pro'tected from fires.
The first three options as defined in Section III.G.2 provides methods for protection from fires of eqtripment needed for hot shutdown:
~1.
Redundant systems including cables, equipment, and associated circuits may be separated by a three-hour fire rated barrier; or, 2.
Redundant systems.tncludi.ng cables, equipment and associated circuits may be separated by a horizontal distance of more than'201 feet with no inter-vening combustibles.
In addition, fire detection and 'an automatic fire suppression system are required; or, 3.'
Redundant systems including cables, egoipment and associated circuits.may by enclosed by a one-hour fire rated barrier.
In addition, fire detectors and an automatic fire suppression system are. required.
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. The last option as defined by Section III.G.3 provides an alternativ capability to the redur. dant trains damaged by a fire.
Alternative shutdown equipment must be independent of the cable 4.
i ment and associated circuits of the redundant systems damaged Associated Circuits of Concern The following discussion providis A) a definition of associated c Appendix R consideration..B) the guidelines for protecting th
) the in-capability from the fire-induced failures of associated circuits an The definition formation' required hy the staff to review associated circuits.
gener c letterf-i of associated circuits has not changed from the February -20,1981 It is important'to note that our interest is only but is merely clarified.
h tdown.
with those circuit (cables) whose fire-induced failure cou d
The guidelines for protecting the safe shutdown capability.
These guidelines should failures of associated circuits are not requirements.
These guidelines do noh limit the alter be used only as guidaned when needed.
ility.
native's available to the licensee for protecting the shutdown capab d
All proposed methods for protection of the shutd'own capa failures will be evaluated by the staff for acceptability 4
Our concern is that circuits within the fire area Nill, receive fir A.
which can affect shutdown capability and t ere y pb, revent h
_ Associated Circuits
- of Concern are defined shutdown.
(safety related, non-safety related, Class 1E, and non-C I
- The definition for associated circuits is not exactly the same i
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as the definition presented in IEEE-384-1977.
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3-Have 'a physical separation less than that required by Section III.G.2 1.
m of Appendix R,.and; 2.
Have one of the following:-
q acommonpowersourcewiththeshutdownequipment(redun"dantor a.
alternat. ve) and the power source is not electrically protected i
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from the circuit of concerp by coordinated bieakers, fu:es, or similar devices (see diagram 2a), or
- s a connection to circuits of equipment whose spurious opiration b.
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would adversely affect,the shutdown capability (e.g., RHR/RCS,
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isolation valves, ADS valves, PORVs, steam generator atmosph'e'ric l
dump valves, instrumentation, steam bypass, etc.) (see diagram 2b), or i
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a comon enclosure (e.g., raceway, panel, junction) with the shutdown' c.
cables (redundant and alternative) and, (1) are not electrically protected by circuit breakers, fuses or simi-lar devices, or (2) will allow propaga. tion of the fire into the common enclosure, (see diagram 2c).
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EXAMPLES OF ASSOCI ATED CIRCUITS OF CONCERil.
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the appropriate sub-paragraphs (a-f)
"rt'& "M a/f*d of section III.G-2 of Appendix R.
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Diagram 2A Diagram 2B
' Diagram 2C
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The following guidelines are for protecting the shutdown capability from B.
The guidance fire-induced failures of circuits (cables) in the fire area.
i provided below for interrupting devices applies only to new devices insta to provide electrical isolation of associated circuits of concern, or as l
The shutdown capability f
.part of the alternative or dedicated shutdown system.
may be protected from the adverse effect of damage to associated circuits t
of concern by the following methods:
Provide protectio'n.between the associated circuits of concern and 1.
the shutdown circuits as per Section III.G.2 of Appendix R, or For a common power source case of asso'ciated circuit:
a 2.
a.
l' Provide load fuse / breaker (interrupting devices) to feeder
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fuse / breaker coordination to prevent loss of the redundant or l
To ensure that the following alternative shutdown power source.
coordination criteria are met the foT}owing should apply:
I The associated circuit of concern interrupting devices '
(1)
(breakers or'. fuses) time-overcurrent trip characteristic p
l for all. circuits faults should cause the interrupting f
device to interrupt the fault current prior to initiation of a trip of any upstream interrupting device which will cause a loss of the common pow'er source, The power source shall supply t'he necessary fault current
,(2) for sufficient time to ensure the proper coordination
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without loss of function of the shutdown loads.
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'The acceptability of a particular interrupting device is considered demonstrated if the following criteria are met:
(i) The interrupting device design shall be factory tested to verify overcurrent protection as designed in accordance with the applicable UL, ANSI, or NEMA standards.
(ii) For low and medium voltage switchgear (480 V and above)
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circuit breaker / protective relay periodic testing shall demonstrate that the overall coordination scheme remains within the limits specified in the design criteria. 'This testing may be performed as a serie's of overlapping tests.
(iii)' Molded case circuit breakers shall peridically be manually
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exercised and inspected to insure ease of operation. On a rotating refueling outage basis a sample of these breakers shall be tested to determine that breaker drift is.within tha' al'10wed by the design criteria.
Breakersshould be t
tested in accordance with an accepted QC testing methodology such as MIL STD 10 5 D.
(iv)
Fuses when used as interrupting devices do not require periodic testing, due to their stability, lack of drif.t,~
and high reliability. Administrative controls must insure that replacement fuses with ratings other than those selected for proper coordinating are not accidentally used.
For circuits o,f equipment and/or components whose spurious operation b.
would affect the capability to s'afely shutdown:
. pro _ vide a means to isolate the equipment and/or comp (1) the fire area prior to the fire (i.e., remove power cables, open circuit breakers); or
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provide electrical isolation that prevents spurious opera (2) fuses, ampli-
. Pot,ential isolation devices include. breakers, fiers, control switches, current XFRS, fiber optic couplers.
relays and transducers; or provide a means to detect spunious operations and the
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(3) dures to defeat the maloperation of equipment (i.e., closure of the block valve if PORY spuriously operates, opening
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the breakers to remove spurious operation of safety inj For common enclosure cases of associated circuits:
c.
provide appropriate measures to prevent propagati (1) fire; and provide electrical protec:$on (i.e., breakers, fuses or (2) similar devices).
d to We recognize that there are different approaches which may b i ted C.
reach the same objective of determining the interaction of ass One approach is to start with the fjre circuits with shutdown systems.
tion area, identify what is in the fire area, and' determine the inter between what is in the fire area and the shutdown systems We have entitled this approach "The Fire Area j
outside the fire area.
A second approach which we~have named "The Sy Approach."
d then determine;-
would be to define the shutdown systems around a fire area an O
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those circuits that are located in the fire' area that are We have prepared two sets of requests for with the shutdown system.
The licensee may choose to respond information, one for each approach.
h licensee.
to either set of requests depending on the approach selected by t FIRE AREA APPROACH d
- 1. ' For each fire area where an alternative o[ dedicated 'sh in accordance with Section III.G.3 of Appendix R is provide following infomation is required to demonstrate that associ
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circuits will not pre.verit operation or cause maloperation of t
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alternative or dedicated sh'utdown method:
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a.' Provide a table that lists all the power cables in the f re are that connect to the same power supply of the. alternative or
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dedicated shutdown method and the function of each pow listed (i.e.,powerforRHRpump).
Provide a table that lists all the cables in the b.
d adversely were considered for possible spurious operation which wo affect shutdown 'and the function of each cable li Provide a table that. lists all the cables in th c'.
share a common enclosure with circuits of the dedicated shutdown systems and the function of eac Show that fire-induced failures (hot shorts, open circuits i
d.
ill shorts to ground) of each of the cables listed in a; b, a i
not prevent. operation or cause maloperation of the alte or dedicated shutdown ' method.
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been provided or modification to existir.g electrica1' isolation has been made, provide detailed electrical schematic drawings that e
show how each cable is isolated from the fire area.
SYSTEMS APPROACH _
F'or each area where an alterpative or dedicated shutdown ' method, in 1.
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
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alternative or dedicated shutdown' method:
Describe the methodology used to assess the potential of associated a.
circuit adversly 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 shutd
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system and the circuits whose spurious operation would affect Additionally, the de'scription should include the shutdown.
methods used to identify if these circuits a,re* associated circuits of concern due to their location in the fire area.
Provide a table that lists all associated circuits of concern b.
located in the fire area.
I5how that fire-induced failures (hot shorts, open circuits or c.
shorts to ground) of each of the cables ~1isted in b will not prevent operation o~r cause maioperation.of the alternatife or.
dedicated shutdown meth'od.
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d.. For each cable listed in b where new electrical isolation provided, provide detailed electrical schematic drawings that show how each cable is isolated from the fire area.
Provide a location at the site or other offic'es where e.
tables and driwings generated by this metho'dology approach for the associated circuits review miy be audited to verify,the information provided above.
HIGH-1.0W PRESSURE' INTERFACE i
i ith high-low-For either approach chosen the following concern deal ng w t
pressure interface shouTd be addressed.
The res.idual heat removal system is generally c low pressure syptem 2.
To that interfaces with the high pressure primary coolant system.
preclude a LOCA through this interface, we require compliance w Thus, the the recommendations of Branch Technical Poqition.RSS 5-1.
interface most likely consists of two redundant and independent motor
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operated valves.. These two motor operated valves and thei i
cables may be-subject to,a single f. ire hazard.
It ik our concern that this single fire could cause'the two valves to open resulting in a fire initiated LOCA thro' ugh the high-low pressure system To assure that this interface and other high-low interface.
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pressure interfaces are adequately, protected from.the effects o
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l single fire, we require the following information:
Identify each high-low pressure interface th~at uses redundant a.
electrically hontrolled dev' ices' (such as two series motor ope valves) to isolate or preclude rupture of any primary coolant i
boundary.'
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b.
For each set 6f redundant valves i~dentified in a.,
verify the redundant cabling (power and control) have adequate physical separation as required by Section III.G.2 of Appendix R.
c.
For each case where adequate separation is r.ct provided, shm: that fire induced failures (hot short; open circuits or short to ground) of tihe cables will not cause maloperati.on and result in a LOCA.
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CRIT'ERIA'FOR EVACUATIf4G
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' EXEMPT 10fiS TO SECTI0tl III G OF APPEf4 DIX R OF 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.
Jt also requires that alternative fire protection configurations, previously appioved by an SER be reexamined for compliance with Section III G is re14ted to fire l
the requirements of Section III.G.
r protection features for ensuring that systems and associated circuits used to achieve and maintain safe shutdown -are free of fire damage.
Fire protection configurations' must eithe:r meet the specific require-i
'ments of Section III.G or an alternative ' fire, protection configuration' must be jdstified by a fire hazard analysis.
The general criteria for accepting an alternative fire protgetion,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.a.chieve cold shutdown -is limited such thay, it can be repaired within a reasonable time (minor repairs wjth components stored on-site).
Fire retardant coatings are not'used as fire barriers.
Modifications required to meet Section III.G would.not enhance
' fire protection safety above that provided by either existing or.
proposed alternatives.
P Modifications required to meet Section III.G would be detrimental to overall facility safety.
the broad spectrum of potential configurations for which exemptions may be, requested, specific criteria that account fo Because o
' the parameters that are important to fire protection and consis safety requirements of all plant-unique configuratio
'l ments in our pr_evious reviews and in the req l
developed.
specific criteria have been developed.
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A passive Section III.G.2 accepts three method, of fire protection.Where a fixed barrier 3-hour fire barrier should be used where possible.
cannot be installed, an automatic suppression system in combination w
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a fire barrier or a separation distance free of com such that there is reasonable assurance that the pro installed in the fire survive.
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,bility is required and a fixed suppression sys em
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It'is area of concern, if it contains a large concentration of cables.
d essential to' remember that these alternative requirements are'not dee However, they provide adequate' protection for those to be equivalent.
configurations in which they ar_e accepted.
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Wheri the fire protection features of each. fire.arek are evaluated
.The defense-
-whole system of'such features must be kept in persp Strengthening any one adequate balance between the different features.can comp The. adequacy of fire protection for any particular plant safety system o
~ area is detennined by analysis of the effects During thes,e active releases to the environment in the event of a fire.
evaluations it is necessary to consider the two-edged nature of fire i
protection ~ features recognized in General
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Ari evaluation must be made.for.each fire area for wh is requested.
parameters:
A.
Area Description walls, floor, $nd ceiling construction ceiling heigh't room volume ventilation I
congestion I
Safe Shutdown Capability
)
B.
number of redundant systems in area d
whether or not system or equiment is. required for hot shut own type of equipment / cables involved
. separatica between redundant components concentration of. combustibles alternative shutdown capability
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3-W Fire Sazard Analysis C.
type and configuration of combustibles in area quantity of combustiblesease of ignition and propagation heat release rate potential
. transient and installed combustibles suppression damage to equipment
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whether the area is continuously manned traffic through the area accessibility of the area l
Fire Protection Existing or Committed D.
' fire detection systems fire extinguishing systems
..ho,s,e station / extinguisher radiant heat shields figuration
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A specific description of the fire protection features of the c lternative. Low is required to justify the compensating features 1
i in areas
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where there are cables.
i eer, If necessary, a team of. experts, including a fire protection-This' visual I
i ting circumstances.
. ill visit the site to determine the ex sinspection is also h
w t
e being The majority of the III.G exemption requests received to denied because they lack specificity.
the extent of the exemption requested, have not provide l
i of the For the request and/or have not provided.a specif i
l alternative.
. nature:
Fix'ed fire barriers less than 3-hour rating.
f 1.
Fire barrier without an automatic fire suppression system tion 2.
Less than 20 feet separation of cables with fire propaga
) and an retardants (e.g., coatings, blankets, covered trays 3.
automatic suppression system.
d and few in-situ For large open areas with few componen ation as in Item
'4.
3 above.
No fixed suppression in.the c.ontr'o1 room.
5.
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4-i f cables for No fixed suppression in areas without a large coricentrat on o ideJf.
which alternative shutdown capability has been prov 6.
ide inforination Our fire research test program is conducting tests to provt ble cond that will be useful to determine the boundary of a t d barrier.
tain Based on dehiations recently approved, specific criteria for c recurring configurations are as follows:
Fir 6 Barrier Less than Three Hours.
h separates This barrier is a wall, floor, ceiling or an enclosure whic one fire area from anot.her'.
ortwohou'rs)
Exemptions may be granted for a lower rating (e'.g., one ho
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i rating. The fire where the fire loading is no more than 1/2 of the barr er rating of the barrier shall'be no less than one hour.
fix rating _
Exemptions may be granted for a fixed barrier with a lower supplemented by a water curtain.
i Barrier or An Automatic Suppression System With Either One Hour F re 20-F oot Separatio_n ates those portions of one division i i The suppressant may
.This bitrrier is an enclosure whit.h separwhich are wit be wate.r or gas.
t which Exemptions may be granted for configurations of redun
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'hav'e compensating features.. For example:
table where:
A.. Separation distances less'than 20 f'eet may be deem d trays, Fire propagation. retardants (i.e., cable, coatings, cove fire propagation conduits, or mineral wool blankets) assure that ill be delayed 1.
through in-situ combustibles will not occur d
ression.
iling assures Distance above a floor level exposure fire and-below l
bject to an that redundant systems will not be simultaneous y su 2.
unaf;ceptatle temperature or heat flux.
be deemed acceptable The ommission of an auto-atic suppression system may B.
iling assures where:
Distance above a floor level. exposure fire and below l
subject to an that redundant systems'will not be simultaneous y 1.
. unacceptable temperature or heat flux.
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.2.
The fire area is required to be raanned continuously 'y the provisions in th.e Technical Specifications.
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