ML18086B458

Forwards Request for Addl Info to Complete Review of Design Descriptions of Mods Re Fire Protection,Per Section III.G.3 of App R to 10CFR50 & 10CFR50.48(c)(5)

ML18086B458
Person / Time
Site:	Salem
Issue date:	04/20/1982
From:	Varga S Office of Nuclear Reactor Regulation
To:	Uderitz R Public Service Enterprise Group
References
NUDOCS 8205040008
Download: ML18086B458 (27)

Text

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Docket Nos. 50-272 and 50-311 Mr. R. A. Uderitz Vice Pre*.sident - Nuclear Public Service Electric and Gas Mail Code T$5A P.O. Box 570 Newark, New Jersey 07101

Dear Mr. Uderitz:

APR 2 0 1982 DISTRIBUTION Docket NRC PDR L PDR NSIC ORB#l Rdg DEisenhut OELD IE ACRS-10 CParrish

\\Al Ross RFerguson-5 TWambach Gray File OPo..v-r

SUBJECT:

FIRE PROTECTION RULE - 10 CFR 50.48(c)(5) - ALTERNATIVE S/.\\FE SHUTDOWN - SECTION III.G.3 OF APPE:NDIX R TO 10 CFR 50~ S*.'l*L.

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S.~LEM UNITS 1 AND 2 The Fire Pro~ection 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 py March 19, 1981.

By letter dated September 18, 1981, you submitted the design description of modifications required to meed: Section III.G.3 of Appendix R to l O CFR 50 for Salem Units 1 and 2.

We have reviewed your submittal and find that additional information is required for us to complete our review.

The infonnation required was originally requested from you by letter dated February 20, 1981. to this letter 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 complete at that time, you will be found in violation of 10 CFR 50.48(c)(5).

Suc.;h a violation will be a continuing one and a civil penalty may be imposed for each da*y the violation continues. states our position with regard to features of your proposed alternative, safe shutdown modifications that we find deficient.

Please provide your responses to these items within 60 days of receipt of this letter. provides a rewortling of the request for fnformati on included with generic letter 81-12.

This rewording is the result of meetings with repre-sentative licensees who felt that clarification of the request would help expedite responses. It does !'lot include any new requests and, therefore, will not adversely affect licensees' ability to respond to generic letter 81-12.

8205040CQ<3 OFFICE. ************************

• • *********************e SURNAME~ **** *******.* ** *.****...

. ***** **********&1**e**** ******** ***************. ************************. *********11************0* ************************ ************************

DATE.........................

• • • • • • • • • • • • • • • • • • • • • • • ~ ***********OG8DGee*O**** ***********************.*........................

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

Mr. R. Enclosure 4 provides information regarding our criteria for evaluating exemption requests from the requirements of Section III.G.2 of Appendix R.

If you have any questions regarding this matter, contact your NRC Project Manager.

ihe reporting and/or recortlkeeping requil"ements contained in this 1 etter are specific to the Sa 1 em Pl ant and affect no other 1 i cense;

• thereforemOMB clearance is not required under P.L.96-511.

Enclosures:

As stated cc w/enc1osures:

See next page Sincerely, priginal signed b'lt~

.s. A. Varga Steven A. Varga, Ch~i:ef Operating Reactors Branch #1

• oivision of licensing OFFICE~ *** ?.~~t1;.a~...

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..... ~~.}.?.1~1 TWamback

~~!.i:1i.§~:::...................

SURNAME.........................

04//1 /82 DATE.........................

.................... ***~

NRC FORM 316 (10*60) NRCM 0240 CIAL RECORD COPY

• • • ** ** **************11ee

• • • • • • • • • • • • • • • • • • • • • • 11*

USGPO: 1981-335-960

Mr. R. A. Uderitz Public Service Electric and Gas Company cc:

Mark J. Wetterhahn, Esquire Conner and Wetterhahn 1747 Pennsylvania Avenue, NW Suite 1050 Washington, D.C.

20006 Richard Fryling, Jr., Esquire Assistant General Solicitor Public Service Electric and Gas Company Mail Code TSE - *P.O. Box 570 Newark, New Jersey 07101 Gene Fisher, Bureau of Chief Bureau of Radiation Protection 380 Scotch Road Trenton, New Jersey 08628 Mr. R. L. Mittl, General Manager -

Corporate Quality Assurance Public Service Electric and Gas Company Mail Code Tl6D - P.O. Box 570 Newark, New Jersey 07101 Mr. Henry J. Midura, General Manager -

Salem Operations Public Service Electric and Gas Company P.O. Box 168 Hancocks Bridge, New Jersey -08038 Salem Free Library 112 West Broadway Salen, New Jersey 08079 Leif J. Norrholm, Resident Inspector Salem Nuclear Generating Station U. S. Nuclear Regulatory Commission Drawer I Hancocks Bridge, New Jersey 08038 Mr. Edwin A. Liden, Manager -

Nuclear Licensing Public Service Electric and Gas Company Mail Code Tl6D - P.O. Box 570 Newark, New Jersey 07101,

Ronald C. Haynes Regional Administrator - Region I U. s. Nuclear *Regulatory Comnission 631 Park Avenue King of Prussia, Pennsylvania 19406

ENCLOSURE l 1-The licensee submittal indicates that the pressurizer heaters were*

evaluated as one of the functions requiring alternate shutdown methods but does not provide additional information on this subject. The licensee should-demonstrate that alternate shutdown pressurizer control and heater power can be provided in the event of a control or relay room fire, or that safe hot shutdown can be maintained for at least 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> without pressurizer control and heater power.

2.. The licensee *should provide the location of the shutdown logic panel area and should state whether the capability of its alternate shutdown system can be impaired by a.fire in this area. If impatnnent can occur, the licensee should state what measures would be taken to circ1111vent the possibility of impaired capability.

3.' The licensee's submittal indicates that atmospheric steam release was evaluated as one of the functions requiring alternate shutdown methods; but does not provide additional infonnation on this subject. The licensee should state whether the steam generator atmospheric dump valves (AOVs) can be operated manually.

If this is not the case, the licensee should demonstrate ADV operability for alternate shutdown.

4. We are concerned that non-safety related associated circuits can sustain fire damage that can affect alternative shutdown circuits and thereby

-- *prevent post-fire alternative safe shutdown.. Our concern includes power, control ahd instrumentation alternative safe shutdown circuits. The licensee should analyze all non safety related associated power, control and instrumentation circuits to see that they meet the requirements of Section III.L of Appendix R *. This means that they are identffied as associated circuits so that they can be evaluated; and that they are isolated from alternative shutdown systems by the fire protection means listed in Section III.G.2 or by suitable isolation devices.

5. Appendi1 R requires that the SNGS must have the capability to achieve cold shutdownconditions within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and maintain cold. shutdown there-after.

The licensee's sul:lnittal should specifically address this item.

e ENCLOSURE 2

1. The licensee's alternate shutdown procedure requires 1nsta11.ation of electrical jumpers and pneumatic bypasses. It is our position that systems and components used to achieve and maintain hot ~tandb.v conditions must be free of fire damage and ca pa bl e to maintai'n such conditions for the duration of the hot standby condition. Systems and components used to achieve and maintain cold shutdown should be either free of fire damage or the fire damage to such system should be limited such that repairs can be made and cold shutdown achieved within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

Repair procedures for cold shutdown systems must be developed and material for repair main-tained onsite. It is our position that electrical or pneumatic jumpers are not a suitable method of repair for cold shutdown.

2. It is our position that direct reading source range flux monitoring be available external to the control room, and be functional after a control or relay room fire.

The present SNGS design does not incorporate this feature.

3. The licensee's submittal proposes deenergization of the control and motive power at two motor control centers in the electrical penetration area for the two residual heat removal (RHR) suction.line valves during normal operation (presumably valves RH l and RH 2) in order to prevent spurious opening of both valves due to a fire in the relay room, since this transient can result in overpressurization of the RHR system with consequent pipe failure and LOCA.

We consider this a satisfactory resolution of our Appendix R concerns regarding the RHR system.

However our acceptance of the SNGS RHR system was based partially on the capabfl ity of system operation from the control room.

We require that the licensee demonstrate that this design change will not appreciably degrade the capability of operating the RHR *system in accordance with the guidance of Branch Technical Position RSB 5-1. Pertinent considerations include operator access during normal cooldown and accident conditions.

As. an aid in response to the items in Enclosures l and 2, we have provided clarification in Enclosure 3. also provides two alternative approaches that the licensee could utilize. The licensee has provided responses to some of the questions in Enclosure 3, but additional information is required.

ENCLOSURE 3 CLARIFICATION OF GEHERIC LETTER On February 20, 1981, generic letter 81-12 was forwarded to a11 reactor licensees with plants 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 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-ments of Section llI.G.2 of Appendix R to 10 CFR 50 were satisfied. Additionally, and Enclosure 2 of the generic letter requested additional

.infonnation concerning those areas of the plant requiring alternative shutdown capability. Section 8 of Enclosure 1 requested information for the systems, equipment and procedures of alternative shutdown capability and Enclosure 2 defined associated circuits and requested information concerning associated circuits fcir those areas requiring alternative shutdown.

In our review of licensee submittals and meetings with licensees, it has become apparent that the request for infonnation should be clarified since a lack of clarit,y could result in the submission of either insufficient or excessive information. Thus, the staff has rewritten Section 8 of Enclosure 1 and of the February 20, 1931 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 Sections 111.G.2 and 111.G.3 of Appendix R.

lndevelop'ingth~s=rewrite.we have considered the comnent of the Nuclear Utility Fire Protection Group.' The enclosed rewrite of the Enclosures contains no new requirements but merely attempts to clarify the request for additional infonnation.

• Licensees who have not responded to the February 20, 1981 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 submittal~ in progress that ~re based upon February 20, 1981 lettsr. Licensees whose response to the February 20, 1981 letter, has been found :incomplete resulting in

• staff identifications of a major unresolved item (i,e., 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 associated circuits, use rewrite of* Enclosure 2).

If additional clarification is needed, please contact the staff Project Manager for youi'" plant.

ATT~C~ENT 1 REWRITE OF SECTION 8 REQUEST FOR ADDITIONAL INFORMATION The fo1lowing is a rewrite of the staff's request for additional infonnation concerning design modification to meet the requirenents of Section III.G.3 of Appendix R.

The following contains no new requests but is merely a rewording of Section 8 of Enclosure 1 of the February 20, 1981 generic letter.

1.

Identify those areas of the plant that will not meet the requirements of Section Ill.G.2 of Appendix Rand, thus alternative shutdown will be provided or an exemption from the requirements of Section III.G.2 of Appendix R will be provided. Additionally provide a state~ent that all other areas of the plar.t are or will be in compliance with Section Ill.G.2 of Appendix R.

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 power.

b.

For those systems identified in "lau for which alternative or dedicated shutdown capability must be provided, list the equipment and components of the normal shutdown system in the fire area and identify 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 portions ther~of used to provi_de 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.

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

Identify the location (fire zone) of the alternative shutdown equipment and/or circuits that bypass the fire area and verify that the alternative shutdown equipment and/or circuits are separated from the fire area in accordance with Secticn III.G.2.

c.

Provide drawings of the alternative shutdown system(s) which highlight any connections to the normal shutdown systems (P&IDs for piping ana componen~s, 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 ror that fire area.

d.

Verify that changes *to safety systems will not degrade safety systems; (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 safety related cabinets and panels; to avoid inadvertent isolation from the control room, the isolation switches should be keylocked or alanned in the control room if in the "local" or "isolated" position; periodic checks should be made to verify that the switch is in the proper position fo~

nonnal operation; and a *single transfer switch or-other new device should not be a source of a fai 1ure which causes *1oss ot' reaunoarrt se1.ft::t.Y systems) *.

• e: Verify that licensee procedures have been or will be developed which descri tasks to be perfonned to effect the shutdown method.

Provide a summary of these procedures outlining operator actions.

• f.. Verify that the manpower required to perform the shutdoWri functions using the pro_cedures 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.

• g. 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 isolation switch is placed in_ the 11local 11 position and that the equipment cannot be operated from 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. Provide Technical Specifications of the surveillance requirements and

• limiting conditions for operation for that equipment not already covered by existing Technical Specifications.

~or _example, if new isolation and control switches are added to a shutdown system, the existing Technical Specification surveillance requirements should be supplemented to verify system/equipment functions from the alternate strutdown station at testing intervals consistent with the guidelines of Regulatory Guide 1.22 a~d IEEE 338.

Credit may be taken for other existing tests using group ovP.rlap test concepts.

. i. 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 power or shutdown on Group l isolation (BWR).

The equipment required 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 summary of these procedures and a list of the material needed for repairs.

ATTACHMENT 2 SAFE SHUTDOWN CAPABILITY.

The following discusses the requirements for ~rotecting redundant and/or a 1 terna ti ve eqµi pment needed for ~-af e shutdown in the event of a *fi r-e.

The requirements of Appendix R address

~ot shutdow~ equipmen~ which must be free of fire damage.

Th.e fo1lowi.ng.. r~qµirements also apply to cold s.hutdown

~quipnent tf the. li.censee elects to demonstrpte that the.equi_p!llent. is *to-b~

free of fire.da~age. Appendix R dQes allow.repairable damage to cold shutdo~m equioment.

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 o~ 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-bility is protected from fires. The first three options as defined in Section III.G.2 provides methods for protection* frcim fires o'! equipment needed for h.ot shutdown:

1. Redundant systens including cables, equipment, and associated circuits_.

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

2.

Redundant systems tncludi:ng caoles, equipment and associated circuits may be separated by a horizontal distan,ce of more than 20 feet with no inter-vening combustibles.

In addition, fire detection and an automatic fire

. suppression system are required; o~,

3. Redundant systems *tncluding cables, equipment and associated circuits may be enclosed by a one-hour fire rated barrier.

In addition, fire detectors

~nd an automatic fire suppression system are required.

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 ~amaged 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 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 February 20, 1981 generic letter; but is merely clarified. It is important to note that our interest is only with those circuit (cables) whose fire-induced failure could affect shutdown.

The guidelines for protecting the safe shutdown capability from the fire-induced failures of associated circuits are not reguirements. These guidelines should be used only as guidance when needed.

These guidelines do not limit the al-ter-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 evaluated by the staff for acceptability.

A.

Our concern is that circuits within the fire area~ill 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 lE~ and non-Class lE) that:

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

..:. ******* 1. Have a physical separation less than that required by Section*nr.G.2 of Appendix R,.and;

2.

Have one of the following:

a. a common power source with the shutdown equipment (redundant or alternative) and the power source is not electrically protected 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 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

c. a contnon enclosure (e.g., raceway, panel, junction) with the shutdown caoles (redundant and alternative) and,

• (l) are not electrically protected by circuit breakers, fuses or simi-lar devices, or

( 2) wi 11 a 11 ow propagation of the fire into the common enclosure, (see diagram 2c).

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co,.,.ol.l clJCLOSi.&.~E The area barr1ers shown above meet the appropriate sub-paragraphs (a-f) of section 111.G-2 of Append1x R.

Diagram 2C 9*

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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 electrical isolation of associated circuits of concern, or as part of the alternative or dedicated shutdown system.

Previous coordina-tion analyses need not be reanalyzed; however, breakers that were not included in previous reviews, will require a coordination analysis.

The shutdovm ca pa bi 1 i ty may be protected from the adv.erse effect of damage to associated circuits of concern by the following methods:

1.

~rovide protection between the associated circuits of concern and the shutdown circuits *as per Section III.G.2 of Appendix R, or

2.

a.

For a conman power source case of associated circuit:

Provide load fuse/breaker {interrupting devices) to feeder fuse/breaker coordination to prevent loss of the redundant or alternative shutdown power source.

To ensure that the fellowing coordination criteria are met the fol1owing should apply:

{1)

The associated circuit of concern interrupting devices (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. interrupting device which w_ill cause a loss of the common power.source, (2)

The power source shall supply the necessary fault current for sufficient time to ensure the proper coordination without loss of function of the shutdown loads;

• The acceptability of a particular interrupting device is considered demonstrated if the follo~ing 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 ~witchgear (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 ~s a series of overlapping tests.

{iii) Molded case circuit breakers shall periodically be manually 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 break~r drift is within that allowed by the deiign criteria.* Breaker~ should be tested in accordance with an accepted QC testing methodology such as MIL STD 10 5 O.

(iv) Fuses when used as interrupting devices do not require periodic testing. Administrative*contr6ls must insure that replacement fuses ~ith ~atin~~ cither than those selected for proper coordination a~e not accidentally used.

b.

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

(1)

• • -* -* provide a means to isolate the equipment and/or components from the fire area prior to the fire (i.e., remove power cables, open circuit breakers); or (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 spur.ious 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);

c.

For common enclosure cases of associated circuits:

(1) provide appropriate measures to prevent propagation of the.

fire; and (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 i~teraction of associated circuits with shutdown systems.

One approach i_s to start with the:. fire area, identify what is in the fire area, and ~etermine 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.

11 A second approach which we have named "The Systems Approach" would be to define the shutdown systems around a fire area and then determine

-~ 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 choose to respond to either set of requests depending on the approach selected by the licensee.

FIRE AREA APPROACH

l. For each fire area where an alternative or dedicate.d shutdown method, in accordance with Section III.G.3 of Appendix R is provided, the following information is required to demonstrate that associatsd circuits will not prevent operation or cause maloperation of the alternative or dedicated shutdown method:

a.

Provide a table that lists all the power cables in the fire area that connect to the same power supply of the alternative or dedicated shutdown method and the function of each power cable listed (i.e., power for RHR pump).

b. Provide a table that lists all the cables in the fire area that were considered for possible spurious operation which would adversely affect shutdown and the 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.

d.

Show that fire-induced failures (hot shorts, open circuits 'or shorts to ground) of each of the cables li~ted in ~~*b, and c will not prevent operation or cause maloperation of the alternative or.dedicated shutdown method.

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

SYSTEMS APPROACH

1. For each area where an alternative or dedicated shutdown method, in accordance with Section III.G.3 of Appendix R is provided, the following information is required to demonstrate that associated circuits will not prevent operation or cause maloperation of the alternative or dedicated shutdown method:

a. Describe the methodology used to assess the potential of associated*

circuit adversly affecting the. alternative or dedicated shutdown capability. The description of the methodology should include the methods used to identify the circuits which share a common power supply or a common enclosure with the alternative or dedicated shutdown system and the circuits whose spurious operation would affect shutdown. Additionally, the description should include the methods used to identify if these circuits are associated circuits of concern due to theit location i~ the fire area.

.

• b. Provide a table that lists all associated circuits of concern lQcated in the fire area.

c. Show that fire-induced failures (hot shorts, open circuits or shorts _to ground) of each of the cable_s listed in b.will not prevent operation or cause maloperation of the alternative or dedicated shutdown 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 area.

e. Provide a location at the site or* other offices where all the tables and drawings generated by this methodology approach for the associated. circuits review may be audited to verify the information provided above.

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

2.

The residual heat removal system is generally a low pressure system that interfaces with the high pressure primary coolant system.

To preclude a LOCA through this interface, we require compliance with the recommendations of Branch Technical Position RSB 5-1. Thus, the interface most likely consists of two redundant and independent motor operated valves. These two motor operated valves and their associated cables may be subject to a single fjre hazard. It is our.concern that this single fire could cause the two valves to open resulting in a fire initiated LOCA through the high-low pressure system interface. To assur~ that this interface and ot~er high-low pressure interfaces are adequatelt protected from the effects of a single fire, we require the following information:

a. Identify each high-low pressure interface that uses redundant electri-cally controlled devices (such as two series motor operated valves) to isolate or preclude rupture of any primary coolant boundary.

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b.

For each set of redundant valves identified in a., -verify-the redundant cabling {power and control) have adequate physical separation as required by Section IlI.G.2 of Appendix R.

c. For each c~se where adequate S~?:ration is ~c~ prcviJe~, sho~ th~t fire induced failures {hot short, open circuits or short to ground) of the cables.will not.cause malcperation and. result in a LOCA.

.IT.ERIA FO~ EVA~UATING EXEMPTIONS TO SECTION II I G OF APPENDIX' OF 10 CFR PART 50 c.m,LU;)Uri.C.

'+

Paragr~ph 50.48 F~~e Protection of 10 CFR Part 50 requires that all nuclear power plants liceDsed prior to January 1, 1979 satisfy the requirements of Section I ILG of Appendix R to 10 CFR Part 50.

It ~lso*requires that alternative fire protec~ion configµrations,.

previously approve~.bY an SER be reexamined for ccxnpl i a nee wi tn...

the requirements of Section III.G. *Section lit.~ is.related to fire pr-otectiol] features f~r ensuring that sys terns and.associated circuits used to achieve and maintain safe shutdown.are free of fire damage.

Fi re prot~ction.~onfi gurations* must either meet the* specific require,-

• ments of Section'III.G Qr an ~1ternative *fire protection configuration*

must be justified by a fire hazard analysis

• The general criteria for accepting an alternative tire pro~ect.ion_configur ations are the fo11Qwing:

The alternative assures that one train of. equipment necessary to achieve hot shutdown from either the control room 0 r emergency control stations is free of fire damage.

The alternative assures that fire damage to_ at 1 east one train of equipment necessary to achieve cold shutdown *is limited such that i~ can be repaired within a reasonable time {minor repairs *w;th c~ponents stored on-site).

• Fi re.retardant coa ti n.. gs are not used as fire barriers.

I Modif;cations required ~o meet Section 111.G )'lOUl~.not enh~n'1~.

• fir~ protection safety above that provided by either existing or proposed alternatives~

Modifications requir-ed to meet Section lll.G wo4ld be d,etrimenta1 tq overal 1 facility s~ fety.

Because of.the broad spectrum of potential configuration$ fat which

• exemptions may be requested, speci fie criteria that-account for al 1 of the parameters that are important ~ fire pr~tecti~n and consistent with safety requirements of al 1 pl ant-unique configurations have not been developed.

However, our evaluations of deviatio~s from these requ~re ments in our ~revious reviews and in the req~ests fa~ lI~.~ exemption~

received to date have identified some recurring conf1gurat1ons for which specific criteria have been developed.

Section 111.G.2 accepts three methods of fire protection. A passive 3-hour fire barrier should be used where possible.

Where a fixed barrier cannot be installed, an automatic suppression ~ystem 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-bility is required and a fixed suppression system installed in the fire area of concern, if it contains a large concentration of cables. It.is essential to remember that these alternative requirements are.not deemed to be equivalent.

How~ver, they provide adequate protection for those configurations in which they are a~cepted.

When the fire protection features of each fire. area are evaluated, the-who1e 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. Strengthen.ing any one

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

The adequacy of fire protection for any particular plant safety system or area is detennined by analysis of the effects.of postulated fire relative to maintaining the ability to safely shutdown the plant and minimize radio-active rel eases to the environment in the event of a fire. Duri n9 thes~

evaluations it is necessary to consider the two-edged nature of fire protecti 9n features recognized in General Design Criterion 3 namely, fire protection should -be provided consistent with other safety considerations.

~n evaluation must be made for each fire area for which an exemption*

is requested. Duririg these evaluations, the staff considers the fo11owing parameters:

A. _Area Description walls, floor, 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 ty-p-e of eq.uipment/cab1es involved repair time for cold shutdown equiprnnt within this area separation between redundant components and in-situ concentration of combustibles

• alternative shutdown capability

• 9 C. *Fire Hazard Analysis type and configuration of combustibles in area quantity of combustibles ease of ignition and proplg~tion 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 Oe Fire Protection Existing or Committed fire detection systems fire extinguishing systems

. -.. ho1e station/extinguisher radiant heat shi ~1 ds A specific description of the fire protection feat~res of the configuration is required to justify the compensating features of ~he alternative. *Low fire loading is not a sufficient basis for granting an exemption in areas

• where there are cables.

If neces*sary, a team of. experts, including a fire protection engineer, will visit the site to determine the existing circumstances. This visual inspection is also considered in th~ review process.

The majority of the III.G exemption requests received to date are being denied becaus~ they lack specificity.

~icensees have not iden~ified the extent of the exemption requested, have not provided a technical basis

.For the request and/or have not provided a specific description of the alternative. We.expect to receive requests for exemption of the following

. nature:

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 automat.i.c supp:ession system.

4.

For large open areas with few components to be protected and few in-situ combustib1es, no automatic suppression system with separation as in Item

~.above.

5.

No fixed suppression in the contr*o1 room.

-*4 -

6 *. No ~ixed suppression in areas without a large concentrat~on of ~ables for which alternative shutdown capability, has been provi d~ *.

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

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

Fire Barrier Less than Three Hours This barrier is a wall, floor, ceiling or an enclosure which separates one *fire area from anothBr~

Exemptions may be granted for a lower rating (e.g., one hou..r or two* ho*urs) where the fire loading is no more than 1/2 of the barrier rating. The fire r~ting of the barrier ?~a11*be no less t~a~ qn~ n9Yf, 1

Exemptions may be granted for a fixed barrier with a fower fix rating supplemented by a water curtain.

An Automatic Suppression System With Either One Hour Fire Barrier or 20-Foot Separation This barrier is an enclosure which separates those portions of one division.

which are within 20 feet of the redundant division. The suppressant may he water or gas*.

Exemptions may be granted for contigurations ot redundant systems which

• hav'e compensating features. For e~ample:

A *. Separation distances less *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 propagatiQn

• through in-situ combustibles will not occµr or wi11 be delayed sufficiently to ensure adequate time for detection an~*suppressio~~

2.

Distance above a floor level exposure fire and below ceiling assures that redundant systems wil 1 not be simultaneously subject to an.

una~ceptable temperature or heat flux.

B.

The ommission of a*n automatic suppression system maY be deemed acceptable

• .where:

1. Distance above a floor level exposure fire and below ceiling assures that redundant systems will not be simultaneously subject to an

.unacceptable temperature* or heat flux.

"t,

• • .2.

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