ML20053A997

Exemption from Certain Fire Protection Rule Schedular Requirements

ML20053A997
Person / Time
Site:	Calvert Cliffs
Issue date:	05/10/1982
From:	Harold Denton Office of Nuclear Reactor Regulation
To:	BALTIMORE GAS & ELECTRIC CO.
Shared Package
ML20053A998	List: ML20053A997
References
NUDOCS 8205270577
Download: ML20053A997 (27)

Text

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r ENCLOSURE 1

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NUCLEAR REGULATORY COMMISSIO!!

In the 11atter of

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E-ALTIMGRE GAS A!!D ELECTRIC

) Docket Mos. 50-317 and 50-318 i

COMPAllY

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l (Calvert Cliffs Huclear Power Plant )

DESIGNATED ORIGINAL

'Jnit : fos. 1 and 2)

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yq EXEMPTIO!1 I.

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The Saltimore Gas and Electric Corgany (theflicensee) is the holder of Facility Operating License Nos. OPR-53 and DPR-59 which authorize cperation I

of the Calvert Cliffs Nuclear Power Plant, Unit Nos. I and 2.

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licenses provide, ancng other things, that they are subject to all rules, regulations and Orders of the Commission new or hereaf ter in effect.

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The facility conprises two pressurized water reactors at the licensee's-t site located in Calvert County, !'aryland.

i II.

i On :tovember 19, 1980, the Conmission published a revised Section 10 CFR h

50.43 and a new Appendix R to 10 CFR 50 regarding fire protection features of 4

l nuclear power plants (45 F.R. 76602). The revised Section 50.48 and Appendix R became;rffective on February 17, 1981.

Section 50.48(c) established the r

1 schedules for satisfying the provisions of Appendix R.

Section III of Appendix 8

R contains fifteen subsections, lettered A through 0, each of which specifies requirements for a particular aspect of the fire protection features at a nuclear power plant. One of these fif teen subsections, III.G., is the subject of this exerption request.

Subsection III.G. specifies detailed requirements for fire protection of the equipment used for safe shutdown by means of separa-tion and barriers (III.G.2).

if the requirements for separation and barriers could not be met in an area, alternative safe shutdown capability, independent of thd area and equipne it in that area, was required (III.G.3.).

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Section 50.48(c) required completion of all modifications to meet the i

provisions of Aopendix R within a specified time from tha effective date of this fire protection rule, February 17, 1981, except for modifications to provide i-al.ternative safe shutdown capability. These'latter modifications (III.G.3.)

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require NRC' review and approval. Hence, Section 50.48(c) requires their l

conpletion within a certain time after NRC approval. The date for submittal of design descriptions of any modifications to provide alternative safe shutdown capability was specified as March 19, 1981.

By letter dated May 18, 1981, the licensee requested exemptions from 10 CFR 50.48(c) with respect to the requirements of Section III.G of Appendix R i

as f'ollows:

(1) Extend from March 19, 1981, to October 1,1981, the date for submittal of I

design descriptions 'of alternative or dedicated shutdown systems for Calvert Cliffs Unit 1 to conply with Section III.G.3., and l

(2) Extend frcn March 19, 1981 to February 1,1982, the date for submittal of 4

design descriptions of alternative or dedicated shutdown systems for i

Calvert Cliffs Unit 2 to conply with Section III.G.3.

l When this Fire Protection Rule was approved by the Commission, it was unde,rst. cod that the time required fo'r each licensee to re-examine those previously-approved configurations at its plant to determine whether they meet the requirements of Section III.G of Appendix R to 10 CFR 50 was not well known and would vary depending upon the degree of conformance. For each item of non-i I

conformance that was found, a fire hazards analysis had to be performed to determine whether the existing configuration provided sufficient fire protection.

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If it 'did, a basis had to be formulated for an exemption request. 'If it did not, i

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modifications to either meet the requirements of Appendix R or to provide some other acceptable configuration, that could be justified for an exemption, had to be designed. Where fire protection features alone could not ensure pro--

tection of safe shutdown capability, alternative safe shutdown capability had to be designed as required by Section III.G.3. of Appendix R.

Depending upon the extensiveness and number of the areas involved, the time required for this re-examination, reanalysis and redesign could vary from a few months to a year or more. The Commission decided, however, to require one, short-term date for~ all licensees in the interest of ensuring a best-effort, expedited completion of compliance with the Fire Protection Rule, recognizing that there would be a nunter of license (; who cculd not "eet these time restraints but who could then

.2 quest appropriate relief through the exerption process. Licensees for 44 of t"e 72 pl3nts to which Appendix R applies (plants with an operating license issued prior to January 1,1979) have requested such schedular relief.

The licensees for the renaining 28 plants made submittals to-meet the schedular requirements of 50.48(c). All of these submittals, however, were deficient in some respects.

In general, nuch of the information requested in a generic letter (81-12) dated February 20, 1981, to the licensees of all 72 plants, was not provided. Therefore, additional time is being used to conplete those submi ttals al so.

III.

Prior to the issuar.ce of Appendix R, Calvert Clif fs Units 1 and 2 had been reviewed against the criteria of Appendix A to the Branch Technical Position 9.5-1 (BTP 9.5-1).

The 3TP 9.5-1 was developed to resolve the lessons learned l

from the fire at 3rcuns Ferry t'uclear Plant.

It is broader in scope than Appendix 3, formed the nucleus of the criteria developed further in Appendix R o

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4 and in its present, r,evised form constitutes the section of the Standard Review Plan used for the review of applications for construction permits and operating

' licenses of new plants.

The review was conpleted by the NPC staff and its fire proter. tion consultants and a Fire Protection Safety Evaluation (FPSER) was issued cn Spetember 14, 1979. With issuance of the FPSER, a few items remained unresolved.

Further discourse between the licensee and the NRC staff resulted in resolution of most of these items as documented in two supplements to the FPSER dated October 2, 1980 and March 18, 1982.

In addition to the licensee's analysis for compliance of Calvert Cliffs Ur.its 1 and 2 to Section III.G.3 of Appendix R, the only remaining fire protection issue concerns the adequacy of protection afforded to certain openings in fire barriers.

Our letter of June 30, 1981 suspended the schedule concerning this item in accordance with 10 CFR 50.43(c)(6).

This issue will be acdressed in fature correspandence.

The F?SER supported the issuance of License Amendcents.41 and 23 to the cperating licenses for Calvert Cliffs Units 1 and 2 which required modifications to be made to plant phy;ical features, systems, and administrative controls to meet the criteria of Appendix A to BTP 9.5-1.

All of these modifications have been completed.

Therefore, Calvert Cliffs Units 1 and 2 have been upgraded to a bigg degree of fire protection already and the extensive reassessment involved

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in this request for additional time is to demonstrate, in detail, the conformarce to the specific requirerents of Section III.G to Appendix R of 10 CFR 50.

As mentioned earlier there are 14 other subsections which contain criteria for other aspects of fire crotection features. One of these, Section.III.L.,

provides the criteria for Alternative Safe Shutdown capability and thus affects the final reassessment and redesign, if necessary, of this feature at the Calvert Cliffs Units 1 and 2.

Nevertheless, compliance with the remaining applicable secticns of Appendix R has been completed on or before the implementation dates required by the Fire Protectic'n Rule, i

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• Based on the above considerations, we find that the licensee has completed a subst3ntial part of the fire prctection features at Calvert Cliffs Units 1 and 2 in cnnfonnance with the requirements of the Fire Protection Rule and is applying significant effort to complete the reassessment of any remaining nodifications which night be necessary for strict conformance with Section III.G. We find that because of the already-completed upgrading of these facilities, there' is no undue risk to the health and safety of the public involved with continued operation until the completion of this reassessnent. Therefore, an exemption should be granted to allow such tine for conpletion.

However, because we have found that most submittals of this reanalysis to date from other licensees have not been cc9plete; that is, not all of the information requested by Generic Letter 81-12 dated February 20, 1981, was provided, we are adding a condition to the Execption that requires all such information to be submitted by the date granted.

IV.

Accordingly, the Commission has determined that, pursuant to 10 CFR 50.12, an exe,{ption is authorized by law and will not endanger life or property or the conmon defense and security and is otherwise in the public interest and hereby grants the following exenptions with respect to the requirements of Section III.G. of Appendix R to 10 CFR 50:

(1) Extend fren March 19, 1981, to October 1,1981, the date for submittal of design descriptions of alternative or dedicated shutdown systens for Calvert Clif fs Unit 1 to conply with Section III.G.3., and (2) Extend from March 19, 1981 to February 1,1982, the date for submittal of design descriptions of alternative or dedicated shutdown systems _ for Calvert Cliffs Unit 2 to conply with Section III.G.3.

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Provided the following condition is net:

The design descriptions of alternative or dedicated shutdown systems to comply with Section III.G.3., as required by $50.48(c)(51 shall include a point-by-point response to cr.ch ite;., in Section 3 cf to generic letter 81-12 dated February 20, 1981, and to each iten in Enclosure 2 to Generic Letter 81-12, dat?d February 20, 1981.

l If the. licensee does not meet the above conditions, the licensee will be found in violation of 10 CFR 50.48(c) even though the submittal nay be made 1

within the time limit granted by the exemption.

If such a violation occurs, imposition of a civil penalty will be considered under Section 234 of the Atonic Energy Act, as anended. Such a violation will be a continuing one beginning with the date set in the exemption for submittal and terainating 1

when all inadequacies are corrected.

A delay in the determination of inadequacy by the staff, caused by the werk-load associated with reviewing all of the submittals falling due near the same t ime, i

will not relieve the licensee of the responsibility for completeness of the submit-t

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tal, nor will such delay cause any p'enalty that may be inposed to be mitigated.

i The NRC staff has determined that the granting of this Exemption will not 1

l result,in any significant environmental inpact and that pursuant to 10 CFR 51.5(d)(4) an environmental impact statement or negative declaration and environ-mental impact appraisal need not be prepared in connection with this action.

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FOR THE !!UCLEAR' REGULATORY COMMISSION W.n-r /J,/.f n

i Harold R. Denton, Director i

Office of !!uclear Reactor Regulation i

l Dated at Bethesda, Maryland this 10th day of May,1982.

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CLAR,1FICATION OF GE!!ERIC LETTER i

tn February 20, 1981, generic letter 81-12 was forwarded to all reactor licensees The letter restated the require-f with plants licensed prior to January 1,1979.

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.ent of Section 50.43 to 10 CFR Part 50 that each licensee would be required 1

to reassess areas of the plant where cables or equipment including associated non-safety circuits of redundant trains of systems necessary to achieve and j

naintain hot shutdown conditions are located to deter. tine whether the require- -

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mants of Section III.G.2 of Appendix R to 10 CFR 50 were satisfied. Additionally, i and Enclosure 2 of the generic letter requested additional

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info'mation concerning those areas of the plant requiring alternative shutdown capability. Section 8 of Enclosure i requested information for the systems, equipment and precedures of alternative shutdown capability and Enclosure 2 t': fir.ed asscciated circuits and requested information cor.cerning associated circuits for those areas requiring alternative shutdown.

f in our review of licensee submittals and meetings with licensees, it has become l

apparent that the request for information should be clarified since a lack i

of clarity could result in the submission of either insufficient or e,xcessive I

l' information? Thus, the staff has rewritten Section 8 of Enclosure 1 and of the February 20, 1981 generic letter. Additionally, further clarification of the definition of associated circuits has been provided to.

aid in the reassessments to determine compliance with the requirements of j

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Sections III.G.2 and III.G.3 of Appendix R.

In developing this= rewrite we have

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considered the ccment of the riuclear Utility Fire Protecticn Group.

I rewrite of the Enciosures contains no new requirer.ents but merely attempts l

l to clarify the request for additional information.

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j 2-Licensees who have not responded to the February 20, 1931 generic letter, may 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, 1931 letter, has been found :inccmplete 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-i mation in order to close open items (i.e., open item for. associated circuits, f

use rewrite of Enclosure 2).

If additional clarification is needed, please contact the staff Project i;3 nager fcr your plant.

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i REWRITE OF SECTION 8 REQUEST FOR ADDITIONAL ItiFORP.ATION The following is a rewrite of the staff's request for additional information

• concerning design modification to meet the recuirenents of Section III.G.3 of

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Appendix E.

The following contains no new requests but is merely a rewording of Section 8 of Enclosure 1 of the February 2',1931 generic letter.

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Identify those areas of the plant that will not meet the requirements of Section III.G.2 of Appendix R ar.d thus alternative shutdown will be provide'di or an exemption from the requirements of Section III.G.2 of Appendix R wil1' be orovided. Additionally provide a statement that all other areas of the plant 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 alternative shutdown systzn(s) provide a complete set of responses to the following requests for aach fire area:

a.

List the system (s) or portions thereof used to provide the shutdown capability with the loss of offsite power.

b.

For those systems identified in "la" for which alternative or dedicated s,hutgown capability must be provided, list the equipment and components of the normal shutdown system in the fire area and identifp the functions of the circuits of the normal shutdown system in the fire area (power to what equipment, control of what components and instrumentation).

Describe the system (s) or portiens thereof used to provide the alternative shutdown capability for the fire area and provide a table that lists the equipment and components of the alternative shutdown system for the fire area.

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For each alternative system identify the function of the new circuits being provided.

Identify the location (fire zone) of the O

alterrative shutdown equipment and/or circuits that bypass the fire area and verify that the alternative shutdown equip ent and/or circuits are separated from the. fire atea in accordance with Secticn III.G.2.

c. ' Provide drawings of the alternative shutdown system (s) which highlight any connections to the norr.al shi2tdown systems (P& ids for piping ano ccmponents, elementary wiring diagrams of electrical cabling). Show the electrical location of all breakers for power cables, and isolation devices for control and instrumentation circuits for the alternative shutdown systems for that fire area.

d.

Verify that changes to safety systems will not degrade safety systems; i-(e.g., new isolation cwitches ar.d control switches should meet design criteria and standards in the FSAR fcr electrical equipment in the syste:n 1

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 safety related cabinets and panels; to avoid inadvertent isolation from the centrol room, the isolation switches should be keylocked or alarmed in the contro'l rocm if in the " local" or " isolated" position; periodic checks should be made to verify that the switch is in the proper position for normal operation; and a single transfer switch or other new device should not be a source of a failure which causes icss of recuncant sefety ?-

systems).

Verify that licensee procedures have been or will. be. develo' ed' which describe the et p

tasks to be perfonaed to effect the shutdown, method.

Provide a sum.ary of these procedures outlining operator actions.

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f.. Verify that the manpcwer required to perform the shutdown -functions using the procedures of e. as well as to prcvide fire brigade members to fight the fire is avillable as rec;uired by the fire brigada technical spcci-fications.

9 Provide a commitment to perform adequate acceptance tests of the alter-native shutdown capability.

These tests should verify that:

equipment operates from the local control station when the transfer or isolatio'n switch is placed in the " local" position and that the equipment cannot be operated from the control room; and that equipment operates from~ the i

j contrcl room but cannot be operated at the local centrol station when th? transfer isolation switch is in the " remote" position.

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Previde Technical Spacificaticns of the surveillance requirements and limiting conditions for operation for that equipment not already covered by existing Technical Specifications.

For example, if new

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isolation and centrol switches are added to a shutdown sys em, 3

the existing Technical Specification surveillance requirements should

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be 'su piemented to verify system / equipment functions from the alternate shutdown station at testing intervals consistent with the guidelines of Regulatory 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 shutdcwn capability, verify that the systems available are adequate to perform the necessary~ shut-4 down function.

The functicns required should be based on previous analyses, if possible (e.g., in the FSAR), such as a loss of normal ac

' power or shutdown on Group 1 isola, tion (BWR).

The equipment required for the alternative c pability should be the same or equivalent to that-relied on in the above analysis, a

j Verify that repair procedures for cold shutdown systems are developed i

and material for repairs is maintained on site.

Provide a su=ary of 1

these proccdures and a. list of the material needed for repairs.

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..tNCLOSURE 2 SAFE SHUTDOWN CAPABILITY I

The folicwing 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 be free of fire damage.

The folltwirg..r.equirements also apply to cold shutdivn equipment if tha licensee elects to de$cnstrate that the equip:;ent. is to be free of. fire. damage. Append 6 R does allow. repairable damage to cold. shutdown ecuipment.

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'I Using the requirements of Sections III.G and III.L of Appendix R, the capa-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 the hot shutdown capa-b'ility is protected from fires.

The first three options as defined in Section III.G.2 provides methods for protection from fires of eq.ripment needed for hot shutdown:

1.

Redundant systems including cables, equipment, and associated circuits l

may be separated by a three-hour fire rated barrier; or, 2.

Redus.da'nt systems including cables, equipment and associated circuits may l

be separated by a harizontal distance of more than 20 feet with no inter-l vening combustibles.

In addition, fire detection and an automatic fi're suppression system are required; or, l

3.

Redundant systems including cables, equipment 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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Alternatfve 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

.AppendimR consideration, B) the guidelines for protecting the safe' shutdown capability from the fire-induced 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 Februiry 20, 1981 generic letter; but is derely clarified.

It is important to note that 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 circuits are not recuirements.

These guidelines should be usec only as guidancd when needed. These guidelines do not limit the alter.

natives available to the licensee for protecting the shutdown capability.

All propos'ed method,s for protection of'the shutdown capability from fire-induced i

failures will be evaluated by the staff for acceptability..

A.

Our concern is that circuits within the fire area will, receive fire damage 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, Class IE, and non-Class 1E) that:

• The definition for associated circuits is not exactly the same as the definition presented in IEEE-334-1977.

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

Have one of the folicwing:

a common power source with the shutdown equipment (redundant or a.

alternative) and the power source is not electrically protected from the circuit of concer,n by coordinated breakers, fuses, or similar devices (see diagram 2a), or b.

a connection to circuits of equipment whose spurious operation would adversely affect the shutdown capability (e.g., RHR/RCS isolation valves, ADS valves, PORVs, steam generator atmospheric dump valves, instrumentation, steam bypass, etc.) (see diagram 2b), or '

a corn.on encicsure (e.g., raceway, panel, function) 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 propagation of the fire into the common enclosure, (see. diagram 2c).

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EXAMPLES OF ASSOCIATED CIRCUITS OF C0f1CERf1 Y

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E u..pm,f,g,espadme The area barriers shown above meet the appropriate sub-paragraphs (a-f) o o.Geri cou M. affec/

of section III.G-2 of Appendix R.

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_4 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 ap2 es only to new devices installed 11 to provide electrical isolation of associated circuits of concern, or as part of the alternative or dedicated shutdown system.

The shutdown capability may be protected 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

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the shutdown circuits as per Section III.G.2 of Appendix R, or For a com:en power source case of associated circuit:

2.

a.

Provide load fuse / breaker (interrupting devices) to feeder fuse / breaker coor 'ination to prevent loss of the redundant or alternative shutdown power source. To ensure that the following coordination criteria are met the 'fol' lowing should apply:

The associated circuit of concern interrupting devices '

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(breakers or fuses) time-overcurrent trip characteristic for all circuits faults should cause the interrupting device to interrupt the fault current prior to initiation of a trip of any upstream inter.rupting device which will-cause a loss of the concon power source,

,(2) The power source shall supply t'he necessary fault current for sufficient time to ensure the proper coordination without loss of function of the shutdown loads.

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,.g 5-4 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 i

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) 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 series of overlapping tests.

(iii) Molded case circuit breakers shall peridically be manually exercised and inspected to insure ease of opsratien. On a rotating refueling cutage basis a sample of these breakers shall be tested to determine that breaker drift is within that allowed by the design criteria. Breakers should be tested in accordance with an accepted QC testing methodology

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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 drift, and high reliability. Administrative controls must insure that replacement fuses with ratings other than those selected for proper coordinating are not accidentally used.

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For circuits of equipment and/or components whose spurious operation would affect the capability to safely shutdown:

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(1) provide a means to isolate the equipment and/or ccmponents frem the fire area prior to the fire (i.e., remove power cables, open circuit breakers); cr (2) provide electrical isolation that prevents spurious operation.

Potential isolation devices include breakers, fuses, ampli-fiers, control switches, current XFRS, fiber optic couplers, relays and transducers; or (3) provide a means to detect spurious operations and then proce -

dures to defeat the maloperation of equipment (i.e., closure of the block valve if PORV spuriously operates, opening of the breakers to remove spurious operation of safety injection);

For common enclosure cases of associated circuits:

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(1) provide appropriate measures to prevent propagation of the fire; and l

(2) provide electrical protection (i.e., breakers, fuses or similar devices)

C.

We recognize that there are different approaches which may be used to reach the same objective of determining the interaction of associated circuits with shutdown systems. One approach is to start with the fire area, ider2tify 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 Fire Area Approach." A second approach which we have named "The Systems Approach" would be to define the shutdcwn systems around a fire area and then determine

7-those circuits that are located in the fire area that are associated with the shutdown system.

'n'e have prepared two sets of requests for information, or,e for each approach. The licensee may choose to respond to either set of requests depending on the approach selected by the licensee.

FIRE AREA APPRDACH 1.

For each fire crea 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 1

dedicated shutdown metned and the functi.on of each power cable listed (i.e., power for RHR pump).

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Provide a table that lists all the cables in the fire area that were considered for pcssib.le spurious operation which would adversely

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affect' shutdown and the function 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.

I d.

Show that fire-induced failures (hot shorts, open circuits or 1

shorts to ground) of each of the cables listed in a; b, and c will not prevent operation or cause maloperation of the alternative or dedicated shutdown method.

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For each cable listed in a, b and c where new electrical isolation has been provided or modification to existir.g electrical isolation has been made, provide detailed elect.rical schematic drawings that show how each cable is isolated from the fire area.

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SYSTEMS APPROACH I

1.

For each area where an alternative or dedicated shutdown method, in i

accordance with Section III.G.3 of Appendix R is provided, the l

following information is reouired to demonstrate that associated circuits will not prevent operation or cause maloperation of the alternative or dedicated shutdown method:

3 a.

Describe the methodology used to assess the potential of associated circuit adversly affecting the alternative or dedicated shutdown.

The description of the methodology should include the methods i

used to identify the circuits which shsre a common power supply or a cc =on enclosure with the alternative or dedicated shutdown system and the circuits whose spurious operation would affect i

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shutdown. Additionally, the description should include the i

methods used to identify if there 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 3

dedicated shutdcwn method.

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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.

Provide a location at the site or other offic'e,s where all the e.

tables and drawings generated by this metho'dology approac,h for the associated circuits review may be audited to verify.the information provided above.

HIGH-LOW PRESSURE INTERFACE For either approach chosen the follcwing concern dealing with high-low pressure interface should be addressed.

2.

The residual heat removal system is generally a icw pressure system that interfaces with the high pressure primary coolant system. To preclude a LOCA through this interface, he require compliance with the recommendations of Branch Technical Position RSB 5-1.

Thus, the i

interface most likely consists of two redundant and independent motor

, operated valves. These two motor operated valves and their associdted cables may be subject to a single f. ire hazard.

It is our concern that this single fire could cause the two valves to open resulting in a f. ire initiated LOCA through the high-1cw pressure system interface. ~ To assure that this interface and other high-low pressare interfaces are adequately. Trotected frca the effects of a single fire, we require the follcwing informationi a.

Identify each high-low pressure interface that uses redundant elect'rically controlled devices' (such as two series motor operated i

valves) to isolate or preclude rupture of any primary coolant

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b.

Fcr each set of redundant valves identified in a., verify the redundant cabling (power and control) have adequate physical separaticn as required by Section III.G.2 of Appendix R.

c.

For each case where adequate saparation is r.ct prcvided, shm: th:t fire induced failures (hot short, open circuits or short to ground) of the cables will not cause maloperation and result in a LOCA.

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EXE.MPTIONS TO SECTION III G 0F APPENDIX R I

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 requirem2nts of Section III.G of Appandix R to 10 CFR Part 50.

It also requires that alternative fire protection configurations, 7

viously appreved by an SSR be reexamined for coe.pliar.ca with the requirements of Section III.G.

Section III.G is related to fira protection feabares for ensuring that systems and associated circuits used to achieve and maintain safe shutdown.are free of fire damage.

Fire protection configurations must either meet the specific require-monts of $ection 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 cecpenents stored on-site).

Fire retardant coatings are not used as fire barriers.

Modificatil5ns 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 eve'rall faci.li ty safe ty.

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 devel oped.

However, our evaluations of deviations from these require-ments in cur previcus reviews and in the request's for III.G exemptions received to date have identified sone recurring configurations for which specific criteria have been developed.

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Section III.G.2 accepts three methods of fire protection.

A passive 3-hcur fire barrier shculd be used where possible.

k'here a fixed barrier cannot be installed, cn autenatic suppression system in ccabination with 4 fire barrier or a separation distance free of combustibles is used if the configurations of systems to be protected and in-situ ccmbustibles are such that there is reasonable assurance that the protected systems will survive.

If this latter condition is not met, alternative shutdown capa-i 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 i

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 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 features. Strengthening any one i

can ccmpensate in some measure 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 thutdown the plant and minimize radio-active releases to the environment in the event of'a fire. During thes,e evaluaticns it is necessary to consider the twc-edged nature of fire protectica fectures reccgnized in General Design Criterion 3 nanely, firk.

protection should be provided consistent with other safety considerations.

An evaluation must be made for each fire area for which an exemption is reques'.ed.

During these evaluations, the staff considers the following parameters:

A.

Area Description

' walls, floer, and ceiling construction ceiling height room volume ventilation congestion B.

Safe Shutdown Capability number of redundant systems in area whether or not system or equiment is required for hot shutdown t)ye of equipment / cables involved repair time for cold shutdown equipant within this area separation between redundant ccaponents and in-situ concentration of combustibles alternative shutdown capability h

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q C., Fire Ha::ard Analysis type and configuration of combustibles in area 1

- 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 J

i D.

Fire Protection Existing or Committed fire detection systems fire extinguishing systems ho,se station / extinguisher j

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A spe'cific description of the fire protection features of the configuration is required to justify the compensating features of the alternative.

Low fire leading is not'a sufficient basis for granting an exemption in areas l

l where there are cables.

If necessary, a tea:n of. experts, including a fire protection engineer, i

will visit the site to determine the existing circumstances. This visual l

inspection is also considered in the review process.

j 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

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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:

l.

Fixed 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'o1 room.

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No fixed suppression in areas without a large concentration of cables for which alternative shutdown capability has been provided.

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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:

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l Fird Barrier less than Three Hours This barrier is a wall, floor, ceiling or an enclosure which separates j

one' fire area from another.

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

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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.

i Exseptions may be granted for a fixed barrier with a icwer fix rating supplemented oy a water curtain.

An Autcmatic Suppression System With Either One Hour Fire Barrier or 10-Foot separation This barrier is an encicsure which separates those portions of one division which are within 20 feet of the redundant division.

The suppressant may be water or gas.

Exemptions may be granted for configurations of redundant systems which

' have compensating features.

For example:

i A.

Separation distances less than 20 feet may be deemed acceptable where:

r 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 detection and' suppression.

l 2.

Distance above a floor level exposure fire and below ceiling assures that redundant systems will not be simultaneously subject to an unaqceptable temperature or heat flux.

B.

The ommission of an automatic suppression system may be deemed acceptable where:

l.

Distance above a floor level exposure fire and bclow ceiling assures that redundant systems will not be simultaneously subject to an unacceptable temperature or heat flux.

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