ML18139B859

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Forwards Request for Addl Info Needed to Determine Whether Mods Satisfy Section III.G.3 of App R to 10CFR50.Means of Providing Direct Indication of Source Range Flux Must Be Available at Alternate Panel
ML18139B859
Person / Time
Site: Surry  Dominion icon.png
Issue date: 04/12/1982
From: Novak T
Office of Nuclear Reactor Regulation
To: Leasburg R
VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
References
NUDOCS 8204290066
Download: ML18139B859 (26)
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Docket Nos. 50-280 50-281 Mr. R. H. Leasburg APR 12 "i982 Vice President - Nuclear Operations Virginia Electric and Power Company Post Office Box 26665 Richmond, Virginia 23261

Dear Mr. Leasburg:

NRC PDR Local PDR D. Eisenhut OELD OI&E (1)

D. Neighbors T. Wambach R. Ferguson (

NSIC ACRS (10)

V. Benaroya

0. Parr

SUBJECT:

FIRE PROTECTION RULE - 10 CFR 50.48(c)(5) - ALTERNATIVE SAFE SHUTDOWN - SECTION III.G.3 OP APPENDIX R TO 10 CFR 50 Surry Power Station, Unit Nos. l f{.2 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.

By 1 etters dated May 19, 1981, February 12, 1982 and February 24, 1982, you submitted the design description of modifications required to meet Section III.G.3 of Appendix R to 10 CFR 50 for Surry Power Station, Unit Nos. l & 2.

We have reviewed your submittals and find that ad~itional info*rmation is required tor us to complete our review.

The information required was originally requested from you by letter dated February 20, 1981. Enclosure 1 to this 1 etter indicates what information you have not supplied. Provide a complete response of items indicated in the enclosure within 60 days of receipt of this letter. If your response is not com-plete 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 a rewording of the request for information included 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 evaluating exemption requests from the requirements of Section III.G.2 of Appendix R.

OFFICE

  • SURNAME
  • DATE. ************************................................................ ************************........................................................................

NRC FORM 318 (10*80) NRCM 0240 OFFICIAL RECORD.COPY USGPO: 1981-335-960

e Mr. R. APR 12 1982 We have reviewed your response regarding the absence of source range flux indication at an independent alternate *shutdown panel.

We find the response unacceptable in that it is the Staff's position that a.. means of providing direct indication of source range flux be available at an alternate pa11el, electrically isolated from the control room.

The Staff does not consider "sampling methods 11 as an acceptab1e alternative to direct indication. *vou are requested to provide a commitment to the installation of such source range flux indication within 60 days of receipt of this letter *.

The reporting and/or recordkeeping requirements contained in this letter affect fewer than ten respondents; therefore, 8MB clearance is not required under P. U.96-511.

Enclosures:

Request for Additional Information cc w/enclosures:

See next page Sincerely, Original signed by:

Thomas M. Novak Thomas M. Novak, Assistant Director for Operating Reactors Division of Licensing NRG FORM 318 (10-80) NRCM 0240 OFFICIAL RECORD <..OPY USGPO: 1981-335-960

Mr. R.H. Leasburg Virginia Electric and Power Company cc: *Mr. Michael W. Maupin Hunton and Williams Post Office Box 1535 Richmond, Virginia 23213 Mr. J. L. Wilson, Manager P. O. Box 315 Surry, Virginia 23883 Swem Library College of William and Mary Williamsburg, Virginia 23185 Donald J. Burke, Resident Inspector Surry Power Station U.S. Nuclear Regulatory Commission Post Office Box 166 Route l Surry, Virginia 23883 f1p. J. H. Ferguson Executive Vice President - Power Virginia Electric and Power Company Post Office Box 26666 Richmond, Virginia 23261 James P. O'Reilly Regional Administrator - Region II U.S. Nuclear Regulatory Commission 101 Marietta Street, Suite 3100 A~nta, Georgia 30303 *

-_e SURRY POWER STATION, UNITS l AND 2 REQUEST FOR ADDITIONAL INFORMATION APPENDIX. R TO l'O CFR 50..

  • ENCLOSURE 1 *
1.

We have reviewed your submittals regarding associated circuits. From the limited information provided, we cannot conclude that associated circuits have been adequately addressed.* we*request that you provide a point by point response. with respect to the interactions of asso-ciqted circuits as outlined in Enclosure 2 of the February 20, 1981

  • . letter (including all requested tables).*.
2.
  • we have teviewed your response regarding the "final design proposal -of the relocation of two Charging Pump Service Water Pumps.

11

. We request that you state your confirmation*.that the relocated pumps *and the associated piping will*be installed to the same level of capability as before relocation. *

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CLARIFICATION OF GENERIC LETTER On* February 20, 1981, generic-letter 81-12.was forwarded to all reactor licensees wi-th p.lants licensed prior to January 1, 1979*. The letter restated the require-ment of Section 50.48 to 10 CFR Part 50 that each licensee would be required to r.eassess areas of the plant where cables or equipment including associated non-safety circuits _of re~undant trains of systems necessary to achieve and**

niaintain hot shutdown conditions are located to determine whether the require-ments of Section III.G.2 of Appendix R to 10 CFR 50 were satisfied. Additionally, Enc1osure land Enclosure 2 of the generic lett~r requested additional

.infonnation concerning those areas of the plant requiring alternative shutdown c~pability *. '<Section 8 of Enclosure 1 requested infonnation for the systems,.

equipment and procedures of alternative shutdown ~apability and Enclosure*2

  • defined associated circuits and requested information coi:icerning associated*.

circuits for those* areas requiring alternative shutdown.

_In-cfur~_view of licensee submittals arid meetings with licensees, it has become*

apparent that th~:request for information should be clarified since. a lack **

of clarity could result in the*submission of either insufficient or excessive infonnatfon. Thus, the staff has rewritten Section 8 of Enclosure l *and of the *February,20, i9Sl_generic letter. Additionally, further clarification of the definition of *associated circuits has been provided to aid in the reassessments to determine compliance with t~e requirements of Sections III.G.2 and III.G.3 of Appendix R.

In developing this==rewri:te we have I

con~idered the-co!TiTlent of the Nuclear Utility Fire Protection Group.

The attached rewrite of the Enclosures contains no new requiremen~s but merely attempts

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to clarify the request for additional information.

  • Licensees who have not responded to the February 20, 1981 gener*i c 1 etter,

~Y choose to respond to the enclosed request for infonnation *. Since. the enclosed request.fa~ information is not* new, but merely clarification of our previous letter,responding to it should not delay any submittal~ in progress that are *,based upon {{letter dated|date=February 20, 1981|text=February 20, 1981 letter}} a Licensees whose*

respons*e to the* February 20,* 1981 letter, has been found :incomplete resulting in

'staff identifications of a major unresolved item (i ie., associated circui_ts),

  • may choose* to. respond to pertinent secti.ons of the enclosed request for infer".'."
  • ma.tion in order.to close open.items (i.e., open item for.assodated circuits,

~

use rewriterof Enclosure 2).

  • If Jdditional clarification ii needed, _please cont~ct the staff.Project Manager for you~ pla*nt.

. e

.tta_:h_ment. l REWRlT~ 9F SECTION 8 REQUEST FOR ADDITIOrtAL INFORMATION*

The following. is a rewrite of *the staff's request for additional infonnation concerning design *modification to meet the req~i renents of Section lILG.3 of Appendix P..

Thc*follov,ing contains no new requests but.is merely a rewording of

  • section 8 of Enclosure l of the February 20,.l981 generic letter.
l. Ide*ntifr those areas of the *plant that will not meet the requi_rarients of Section III.G.2 of P.ppendix R ar.d*, thus alternati'le shutd~wn will be provide"ci,,

. or an exemption from the requirements of Section III.G.2 of A.ppendix-R will*be

. proviaed. Additionally provide a statement that all o~her areas of the plant

_are or will *be fn compliance with Section III.G.2 of Appendix ~-

For each/Of those fire areas of the plant requiring an alternative shutdown

  • systen (s) provide a complete set of responses to the following requests for
  • each fire area:
a. List the system(s)" or portions thereof used to provide the shutdown

-* _*_,***--capability with the loss of offsite powero *.

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b.

For those systems identified in '.'la" for which alternative or dedicated shutdown capability must be provided, list-the equi~ent and components

  • -of the normal shutdown system in the fire area and id~nti.fy the function_s * *
  • . of t~e*circuits of the no~al_shutdown system in the fire area (power to what equipment, *control of what components and instru~entation)°. Describe_

the system(s) or portions thereof used to provide the alternative shutdown capability for the fire area and pro_vide a table that lists the equipment* *

.and components of the alternative shutdown system for the fire.area.

  • ** e For each alternative system identify the function of the-new circuits being provided.

Identify the location (fire zone) of the alternat,ve shutdown equipment and/or. circuits that bypass the fire area and verify 'that the alternative shutdown equipment a~d/or circuits are separated from the fire area in accordance with Section lll.G.2. *

c.

Provide drawi~gs of the alternative shutdown system(s) which highlight any

    • connections to the normal shutdown systems (P&IDs for piping ana componen'ts, elementary wiring diagrams of electrical cabling).. Show**the el ectr_ical location of all" breakers for power cables, and.isolat.ion devices for

. control.and instrumentation circuits for the alternative shutdown systems

  • , for th~t *fire area *
d. -Verify that changes *to safety systems will not degrade ~afety systems;*

(e.g., new isolation switches ~nd control switches should meet design criteria-and standards in the FSAR for electrical* equipment in the system that the switch is to be i-nstalled; cabinets that t.he switches are to be

  • '*:~oup~d in should also meet the same criteria (FSAR) as other ~afet~
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related c;binets and panels; to avoid inadvertent isolation from the control room, the *iso1 at ion switches shou_l d be keyl oc:ked or a 1 anned in the control_ room if in.the. "local" or "isolateq" position; periodic I

  • checks should be made to verify that the switch is in.the proper position for nonna 1 opera ti on; and a *s i ngl ~ transfer switch or other new device should

. not be a source of a failure which,causes *1oss of reaunaarn~* sc1f~t.1 ~T>~

s.vs terns)

  • _.

Verify that licensee procedures have* been or wi 11 -be developed* which describe the tasks to.be perfonned to effect* the shutdown_ method.

Provide a* summary of these procedures outlining_ operator *actions.

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~. Verify that the manpower required to perform the shutdo~~ functions using the procedures of e~ 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 shoul-0 verify that~ equipment operates from the local control station when the transfer or isolation*

s~itch is placed in. the "local" position and that the equipment cinnot be operated froin the control room; and that equipment operates from* the

~control room but cannot be operated at the local control station when the transfer isolation switch is in the "remote" position.

h. Provid~ Technical Specifications of the surveillance requiremen~s and limitir:ig conditions for operation.for that equipment not alrea~y
  • * *:-*-c-o*vered by existing Te_chnical Specification~. For _example, if new 4*

isolation and cont~ol switches are added to a shutdown system,

    • the existing Technic~l Specification surveillance requirements* should

.be supplemented t~ verify system(equipment functions from the alternat~

shtitdown.station a:t te~ting inter~als consistent with the guidelines of*

Re9ulatory Guide 1.22 and IEEE 338. Credit may be. taken for other existing 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 ~u~ctions r~quired should be bas~d on previous analyses, if possible (e.g., in the FSAR), such as a loss of nonnal ac power or 'shutdown on Group l iso1a.tion (BWR).

The equipmen~ required for the alternative capability should be the same or equivalent to that relied on in the above analysis.

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Verify. tha*t repair *procedures for co1d. shutdown systens are developed

  • and material* for repairs is maintained on site. Provide a summary *of

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the~£ procedures and a:list of the material needed for repairs.*

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..* FE "SHUTDOWN.'cAPAB.ILITY

  • e The following discusses *the requirements for.protecting redundant and/or alternative.equipment needed for safe shutdown in the e~ent of a fire. The

~equirements of Appendix R*address hot shutdown equipment which most be

  • rree of fire* damage *. Th.e :follow.i:.ng.. r~qlJirements also-apply to cold s.hutdown_

~quii:ment *tt the. li:censee elects to *demonstrpte that the.equi.P!f!ent. is 0to-be I

free of. ftre.damage.

App.endfic:R does allow.re.pairable damage to cold shutdown

~

eQuioment.

Usfng the requirements of S~ct1ons III.G and III.L of Appendix R, the capa~

bility*to achi~ve hot shutdown must exist given a fire 1n an~ area* ~f 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~.rR provides four methods for ensuring that th.e hot shutdown capa-bility ; s protected from fires. The first three options as defined in Section.

III.G.? prov1des methods ~or protection-from ftres of eq~ipment needed for hot shutdown:

  • 1
  • L _.-R~dttridant systems including cables, equipm_ent, and associated circuits may be separated by a three-hour fire rated barrier; or,
2.

Redundant systems. tncludt_ng caol es, equipment* arid associated circuits may be separated by a horizontal distance of more than 20-feet with no inter-vening combustibles. In additio!'l, fire detection and an automatic fire*

suppression sy~tem are required; or, 3~. Redundant systems fncludi_ng cables, eqaipment and associated circuits may*

-by enclosed by a one-hour fire rated barrier.

In addition, fire detectors

~nd an automatic fire suppression system are required.

..

  • e The last-option as _defined by Section III.G.3 provides an alternative shutdown*

capability to the redundant trains damaged by a fire.

4~

Alternative shutdown equipment must be independent of the *cables~ equip-ment and associated circuits of the redundant systems damaged by the fire:

Associated Circuits of Concern The following discussion provides A) a definition of associated circuits for Appendix R consideration, B) the guidelines for protecting the safe'shutdown

. capability from t:he fire-indu.ced*failures of. associated circuits and C) the in~..

formation required by the staff. to review associated circuits.

  • The definition of. associated circuits has. not changed from the Februa*ry *20, 1981.gener.ic letter;*

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but is merely clarified. It is important to note thQt our interest is only with those circuit (cables) whose fire-induced failure could effect shutdown!

  • The guidelines *for protecting the safe shutdown capability from the fire-induced failures of associated ctrcuits are not requirements. The~e guidelines should

.. ~~.. '-use~- only as guidance when needed. These guidelines do not' limit the -~lter-.

  • '",a,...-...

natives available to the licensee for protecting the shutdown capability.

  • - All proposed methods for protection of the shutdown capability from fire-induced failures will be eva.luated by the* staff for acceptability...
  • A.

Our concern is that circuits within the.fi.re area.\\\\'.Hl. receive fir_e da_mage which can affect shutdown capability and thereby prevent post~fire safe shutdown. Associated Circuits* of Concern are defined as those cables (safety related, non-safety related,Cla~s 1E9 and non-Class lE) that:

  • The definition for associated circuits is not exac.tly the same as the definition presented in IEEE-384-1977~

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1.

Have a physical separation less than that required by Section III.G.2 of Appendix R,.and;

2.

Have one of the following:.

a. a common pow~r source with the shutdown *equipment (redundant or alternative) and the power source is not electrically prot~cted.

from the circuit of concerp by coordinated breakers, fuses, or similar devices (see diagram 2a)~ or*

b *. a connection to circuits of equipment.whose spurious operatJon would adversely affect the shutdown capability (e.g., RHR/RCS I

~

  • isolation valves~ ADS valves, PORVs, steam generator *atmospheric dump valves, instrumentation, steam bypass, etc.) (see diagram 2b), or I.
c. a ~o~on.enclosure (e.g., raceway, panel, junction) with the shutdown*

caf>les (redundant and alterliati*ve) and,

. : *-....___*(1}.. ~re not electricalJy protected by circuit breakers, fuses or sjmi-

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lar devices. or

.. ( 2) wi 11 a 11 ow propagation of the fire into the common enclosure;.(s~e diagram*2~).

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BUS Diagram 2A EXAMPLES OF ASSOCIATED CIRCUITS OF CONCERN rtl\\E.

  • AREA

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I Diagram 28"

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The area barriers shown above meet

  • tha ap~ropriate sub-paragraphs (a-f)'

of sec ti on II I. G-2 of Appendix R.

I Diagram 2C

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B.

The following guidelines are for protecting the shutdown capability from fire-induced failures of circuits (cables) in the.fire area. *The guidance provided *below for interrupting devices applies only to new devices installed to provide elec~rical isolation of associated circuits of concern, or as

. part of the alternative or dedicated shutdown system. The shutdown capability may be prot,ected from the adverse effect of damage to associated circuits of concern by the following methods:

1..

Provide protection between the associated circuits of concern and*

I the shutdow*n_ circuits as per Section III.G.2 of Appendix R, or 2.. a:*f'. For a conman power source case of associate~. circuit: *

  • Provide load fuse/breaker (interrupting devices) to feeder

. fuse/breaker coordination to prevent loss of the redundant ~r alternative shutdown power source. To ensure that the follo~ing coordination criteria are met the *foi)owing should apply: *

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{l},., The associated circuit of* concern interrupting devices. *:.

(breakers *or.fuses) time-overcurrent trip characteristic for all c*ircuits faults_ should. cause the interrupting device to interrupt the fault current priCilr to initiation of a trip of any upstream interrupting device which will*

cause a loss o*f the common power source, Ji) The power source shall. supply the necessary fault current for sufficient time to ensure the proper coordinatiori*

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 th*e applicable UL, ANSI, or NEMA standards.

{ii) For low and medium voltage switchgear {480 V and above) circuit breaker/protective*relay periodic testing shall.

demonstrate that the overaJl coordination schem~ remains w_ithin. the limits specified in the design criteria~ Thi~

testing may be performed as* a series-of overlapping ~ests *

{iii). Molded case circuit breakers sha11 peridically be manually exercised and inspected to in~ure ~ase of operationo 0~

a rotating refueling outage basis a sample*of these breakers shall be tested to determine that breaker drift is withi_n.

that allowed by the design criteria.*. Breakers.should be**

. 4.*

    • ~-

--- \\:*~ - tested in accordance with an accepted QC testing methodology such as MIL STD 10 5. D. *.

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{iv) Fuses when used as interrupting devices do.not require periodic testing, due to their stabilJty, lack of drift, and high reliability.,Administrative controls must insure that replacement fuses with ratings other than those selected for proper coordinating are not accidentally used.

b.

For circuits of equipmel')t an~/or components whose spu*rious operation would affect the capability to safely shutdown:

  • e 6 -

. (1) provide a means to isolate the equipment and/or-components from the fire area prior to the fire (i.e., remove powe~ cabl~s, open circuit breakers); or (2) *provide electrical isolation that prevents spur_ious operation.

Po!ential isolation devices include.breakers, fuses, ampli-fiers, control switches, current XFRS, fiber optic couplers, relays and tran~ducers; or (3) provide a means to.detect spu~ious operations and then proce-*

dures to defeat the maloperation of equipment.(i.e., closure

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of the block valve if PORV spuriously oper~~es, opening of the breakers to remove spurious operation of safety injection);

c. For c9nmon enclosure cases of associated circuits:

(1 ) pro vi de appropriate measures to prevent p.ropaga ti ori. of_ the. *

(2) provide electrical prot~cti~n (i.e., breakers, fuses.or*

similar.devi~es)

  • C.

We rec?gnize that there are d~fferent approaches which may be used to.

reach the same objective of deteimining the interiction of-associated circuits with shutdown systems. One approach is to start wit~ the fire area, id~Qtify what is in the fire area, and'determine the interaction between what is in the fire area and the shutdown systems which are outside the fire area.

We have entitled this approach, "The:Fi~e Ar~a Approach." A second

  • approach which w*e
  • ha*ve name~

11Th_e Systems Approach" I

would be to:define the shutdown systeml around a fire ar~a and then determine

  • e e those circuits that are located in the fire area that are associated with the shutdown system.

We have prepared two sets of requests for

-information, one for each approach.

The licensee may cho~se to.respond.

to either set _o_f. requests depending on the approach selected by-the licel}see.

  • . FI RE* AREA APPROACH 1 ~
  • For eac*h fire area where an alternative or dedicate~ shutdown method,.

in accordance with Section. 111.G.3 of Appendix R is provided, the follow~ng infonna~ion is required ~ deroonstrate that ass_ociate4 circuits will not pre.vent operation or cause maloperation of the alternative or dedicated shut~own method:

.... ~--

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Provide a table that lists pll the P?~er_cables in. the fire ~rea th.at 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. P~oxjde a table that lists al 1 the cables in* the fire area that
c.

were consider~d for ~ossible spurious operation which would ac:lvers~ly affec~ ~hutdown and~~~ function of eacn pable lis~~d, Provide a table that lists all the cables in th~ fire area that

- I-share a commqn e*nclosµre. 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 ~round) of each of the cables. listed in ij; b~ and c will not prevent pperation or cau~e m~loperation of the* alternative or dedicated shutdown method~.

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e.
  • For each cable listed in a, band c where-new electrical isolation has been provided-Or modification to existicg el~ctrical isolation has been made, provide detailed electrica1 $Chematic drawings tha't

~how.how each cable is isolated from.th~ fire area *.

SYSTEMS APPROACH

1.
  • For each area where an alternative or dedicated shutdown method, in accordance with Secti_on III.G.3 of Appendix R ~s provided, the.

following information is required to demonstrate that asso~iated circuits Wil 1 not prevent operation *or cause maloperation* of. the**

  • * *~

alternative or-dedicated shutdown method:

4.... ~

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a. Describe the methodology used to assess the potential of assoc.iated circuit adversly affecting the alternative or dedicated shµtdown.

The description of the* methodology should inc_lude the* m_ethods used to identify the ci_rcuits which share a corrmon power supply_

  • .,_____ or a comnon enclosure with the alternative or dedicated *shutdown*

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system and the circuits whose spurious operation would affect shutdown. Additionally, the descrip~ion 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 lmcated in the fire area.
c. Show th~t fire-induced failures (hot shorts, open circuits or

~shorts to ground) of eac~. or the ca~les listed in b will not prevent opera'ti on or cause ma 1 opera ti on of the *a 1 tern a ti ve or deditated sh~tdown method.

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  • 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 ar~a.

e. Provide a location at the site or other offii~s where a11 the ta~les and drawings generated by this methodology approacp for the associated circuits review may*be audited to verify.~he..

information provided above.

HIGH-LOW PRESSURE INTERFACE

-For either ap*proach* chosen the following c~ncer~ d_ealing with high-low.

pressure interface should be addressed.**

2. The res_idual heat removal system is generally a low pressure system that. i_nterfaces with the high pressure primary cool ant system. To preclude a LOCA th.rough this interface, we requi.re compliance with
    • .**~--

the recommendations of Branch Technical Position. RSB 5-1 *. Thus,* the*

4 interf.pce most likely, consists of two redundant and independent motor operated valves *.. These two motor operated valves and their associlited_

cables may be*s~bject to~ single fnre hazard. It is our concern tha~

this single fire could cause the two valves to ope'n resulting in a fire initiated LOCA through the high-low pr~ssure system interface. To assure th~t this jnterface and_ other high~low pressure interfaces are adequately protected.from the effects.of a single fire, we require the fol1owing information:

a *. ~Identify each high-low pressure interfaGe_ that uses redupdant electrically controlled dev,~es* (such as_t"(O series motor operated

  • v~lves) to jsolate or prec~ud~ *rupture.of any primary coolant

. boundary.

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b.

For each set of. redundant valves fdentified in a., verify the redundant_ cabling (pow~r and control) have adequate physical separation as required by Section 111.G.2 of Appendix R.

c.

For ~ac~ case wher.e adequate s1:p~ration is r.c*:: ;ircviJe..i, sh::>t: thi:t fire induced failures (hot short; open *circuits or s~ort to ground)

- of the cables will not cause maloperation and result in a LOCA *

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CRITERIA FOR EVAl~UAflNG E'XEMP~IO*N* SECTION I II G OF APPENDIX Re OF 10 CFR PART 50 Paragr~ph 50.48 Fi re Protection of l O CFR P*art 50 requires that al 1 nuclear power plants licensed prior to January 1, 1~79 satisfy the require~ents of* Section 111.G of Appendix R to 10 CFR Part 50.

It ~lso requires that alternative fire protection configurations, previously approved _by'an SER be.reexamined for ccxnpliance with*

tlie requirements of Section III.G.Section III.. G is related to fire protectio~ fe~tures for ensuring that systems and associated circuits used to a<:hi eve and maintain s~fe

  • shutdown.are..fre*e of fire damage.

Fir~ prot~ction configurations must eith~r meet the-specific require-*

.

  • nients of Secti~n I II.* G l'r an al t~rnf!ti~e *fire prot~ction confi gurat1on
  • mt,tst p~ justified by a fire hazard analysis.
  • The general cr.i teri a for accepting an al ternativ.e fire pr9~~ct.i~n.. confi_gur..

ations ijre the f~llow,ng~

  • The.altern~tive assures that one train of equipment necessary to achieve. ho_t shutdown* from either the control room or emergency control station~ is. free-of fire damage.

,.~

The al ternati v~ ~s~ur-E;s that fi r,e damage to ~1: 1 eai;t one train of equipment nece~sary tq achieve cold shutclown *is 1 imi ted ~i.ich t~a~

it can be repaired within a reasonable time* (minor repairs with*

.

  • components _stored on-site).

Fire.retardant coatin.. gs are not*used as fire barriers..

--~- '.****Mo.clifications required to meet Sectipn III.G would.not enhaoc~

'fire prot~c~i9f) s~fety ab~"~ ~pa1: providecl by either exi stitjg qr proposed aiternat,ves..

Modifications requir,ed. to meet Section 111.G would be detrimental to overall facility s~f~ty.

Beca*use of the broad spectrum of potential _configurations fQr which

. exemptions mqy be, reques~ed, speci fie 7ri teri a th~t account f~r al 1 o!

  • the param~ters that are important to* fl re pr~tec.t,~n an~ cpns, s,tent w, th safety requirement$ of al 1 pl ant:unique conr, g~rat,ons *have not be:n deve1 oped.

However, our eval uat,ons of dev, at,ops from these requ~ re-.

ments in our e_revious reviews.and in th~ req~ests-fo: II~.~ exemptrnn~

received to date _have identif1 ed some recurr,r1g c;onf1 g~r~t,on~ fi;,r which spe~ific crt\\eri~ have b~en developed.

.. ;.. --- ~*....

~-

.e

- 2 Section.111.G.2 accepts three methods of fire protection.

A ~assive 3-hotir fire barrier should be used where possible.

Where a fixed barrier cannot be installed. an automatic suppression system in combination with

~ 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-bi.lity is required'and a fixed suppression system installed in the fire area of.concern, if it contains a large concentration of cableso 1t*1s essential to re~ember that these alternative requirements are** not deemed

. to be equivalent.

However, they provide adequate proteGtion for those configurations in which they are accepted..

When the fire protection features of each fire.area are evaluated, 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 featur_es.

Strengthening any one

-can-.compensate in some measure for weaknesses, known or unknown in.others.

The adeq1,1acy of fire protection for any particular plant saf~ty system-or qrea is detenninecl by analysis'of the effect$ of postulated fire relative to mc$intaining the qbility to safely shutdown the plant and minimize ra~io-active rel eases* to the environment in the event of a fire. Du11ing these evaluations it is necessary to consider the twQ-edged nature of fire' '

  • protection.features recognized in General Desig~ Criterion 3 namely, fire
  • protection should -be provided consi ~tent with other sa~ety cons-i de.rations..

- An evaluation must be made.for _each fire area for which an exemption

    • ** fs "'requested.

During these evaluations, the staff considers the following

.. parameters-:........ *.

~ *'--

... ~

A *. Area Description

\\ilalls, floor, and ceiling construction-ceiling heigh~

room volume

. ventilation

~ongestion B.

Safe S~utdown Capability number of redundant systems in area

...,hether or not system or equiment is -required for hot shL!tdown ty-p-e of equipment/cables involved repair time for cold shutdown equipmnt within this area

-separation between redundant c_omponents_ and in-situ

  • concentration of combustibles

~ alternative shutdown capability

.... C.

Fire Hazard Analysis type and cqnfiguration of combustibles in area quantity of combustibles ease of ignition and propagation heat re1e*ase 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

-~ *.. -.. -~o.;e station/~xtingui sher

-"'~" radian~ hiat

  • shi ~, ds A specific description of the fire protection features of the configuration
  • i$ required to justify ttie compensating features of the alternativ.e.

Low fire loadin9* is not a sufficient basis for granting an exemption in are.as where ther~ are cables.

  • . If necessary, a team of.experts, including a fire protection engineer,

-.~ *-.. will visit the site to determine the existing circumstances. This visual

  • fnspection is also considered in the review process

. denied because they lack specificity. Licensees.have not identified the extent of the exemption.requested, have not provided a technical ba~is

_For the request and/or have not provided.a specific description of the

. al tern a ti ve.

We expect to receive requests for exemption of the fol lowing

.. nature:

1*.

Fiied fi~e barriers less than 3-h6ur ~ating *

~-

Fire barrier without an automat~c fire suppression system.

3. * *Less than 20.feet separation of'cables with fire propagation retardants (e.g., coatings, blankets, co~ere~ trays) and an automatic suppression system.

4o For.1 arge. 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 S\\Jppression in the contr"o1 room.

  • .. -~

I I:

~

.e e 6. -No tixed suppression in areas witho~t a large concentration of cables for*.

-which alternative shutdown capability has been provid~ *.

Our fire research test program is conducting tests to provide infonnation that will be useful to determine the boundary of acceptable conditions for fire protecti~n configurations which *do not include a fire rated barrier~

Based on deviations recently approved~ specific criteria for certain recurring configurations are as follows:

Fire* Sarrier. Less than Three Hours This barrier is a-wall, floor, ~eiling or an enclosure which separates one fire area from anoth~r~

Exemptions may be* granted for a lower rating (e*.g., one hour or two hours)

-~here the fire loading is no more than 1/2 of the barrier ratingo

  • The fire rati~i of the barrier shall.be no less than_one hour.

Exemptions may be granted for a fixed b.arrier 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 w~ich separates those portions of 011e division.

  • .:----whi~h are within 20 feet of the redundant division *. The Sl.lppres*sant may be water,.._~r gas. _

Exemptions may be granted for configurations of redundant sys~e,~ which

  • have compensating features *.. For example:

A.

.. Separation di's~ances 1 ess *than 20 feet may be deemed acceptable where:

1. Fire propagation retardants (i.e., cable coatings, covered trays,
  • conduits, or mineral wool blankets) assure that fire propagation
  • through in-situ combustibles will not occur or will be delayed sufficiently to ensure adequate time for aetection ancl *suppression..

~-

  • Distance above a floor, level exposure fire and b~low ceilin_g assures that redundant systems will. not be si~ultaneously subject to an.

unatceptable temperature or heat flux.

B.

The ommission of an automatic suppression system may be deemed acceptable

. where:.

1$

1. Oi~tance abov~ a floor levei.exposur~ fire and b~low ceiling assures that redundant systems win. not be simultaneously subje.ct to an

µnacceptable* temperature.or heat flux* *

~

-=---*

~

u

- 5

.2.

The fire area is required to be manned continuously by the provisions in the Technical Specifications.

'*~

'

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