ML20054K832

Forwards Final & Complete Response to NRC 810220 Request Re Fire Protection Safe Shutdown Capability

ML20054K832
Person / Time
Site:	Quad Cities
Issue date:	07/01/1982
From:	Rausch T COMMONWEALTH EDISON CO.
To:	Eisenhut D Office of Nuclear Reactor Regulation
Shared Package
ML20054K833	List: ML20054K832
References
4458N, GL-81-12, NUDOCS 8207060197
Download: ML20054K832 (13)

Text

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/'N~)_one Commonwealth Edison First N;tionti Plaza. Chicgo, Ilhnois l

l Address Reply to: Post Office Box 767 (x 's

_, Chicago, Illinois 6%90 l

I July 1, 1982 l Mr. Darrell G. Eisenhut , Director Division of Licensing U.S. Nuclear Regulatory Commission t!a s h ing ton, DC 20555

Subject:

Quad Cities Station Units 1 and 2 Response to Fire Protection Shutdown NRC In formation Requests NRC Docket Nos. 50-254 and 50-265 References (a): D. G. Eisenhut letter to All Power Reactor Licensees with Plant Licensed Prior to January 1,1979, dated February 20, 1981 (Generic Lette r 81-12) .

Dear Mr. Eisenhu t :

In Reference (a), information was requested concerning the fire protection safe shutdown capability of Quad Cities Station, Unit s 1 & 2.

Commonwealth Edison provided information relevant to this request in submittals dated January 23, 1980, February 29, 1980, Jun e 9, 1980, Ma y 19, 1981, August 31, 1981, January 29, 1982, and March 16, 1982. The attached Enclosures, A through D, provide a final and complete response to the information requested in Reference (a) .

In the submittals dated January 23, 1980, Februa ry 29, 1980, and June 9, 1980, responses to Questions 8a-1 listed in Enclosure 1 o f Reference (a) were provided. These questions requested information concerning shutdown methods, manpower requirements, procedures, and technical specification requirements related to safe shutdown. Much o f the information provided in these submittals has become dated and is in need of clarification. The attached Enclosure A provides updated responses to Questions 8a-l.

The attached Enclosure B provides a summary o f the responses to Questions lA-C and 2A-D listed in Enclosure 2 of Reference (a) concerning associated circuits. Enclosure B also includes the final response to Questions ID and 1E listing the exact shutdown methods and necessary safe shutdown modifications for Quad Cities Station. It should be noted that necessary procedures reflecting the proposed shutdown methods will not be written and proposed modifications will not be implemented until final NRC approval is received. Submitted with this letter and referenced in enclosure 8 are six copies of the Quad Cities Station 1 & 2 Fire Protection Associated Circuits Analysis and Modifications Report . Copie s Oko!oO

D. G. Eisenhut July 1, 1982 of the cable discrepancy lists, previously submitted on March 16, 1982, aill be revised and resubmitted by August 16, 1982 as a supplement to the modifications report, Found in the attached Enclosure C is a statement concerning Commonwealth Edison's position related to source range monitoring independent of the control room. This statement is in response to the recently established NRC position concerning this issue.

Having reviewed 10 C"R 50.48 and Appendix R to 10 CFR 50, we have determined that it is necessary to request exemption from certain requirements o f paragraph III.G.3 t o Appendix R. Enclosure D to this letter lists the requested exemptions and provides a technical basis for each. This request is being made pursuant to the provisions of 10 CFR 50.12.

Because of the extreme complexity and magnitude o f the fire protection safe shutdown issue, we believe that it is in the best interests for all parties concerned that a meeting be held as soon as possible to discuss the proposed safe shutdown methods, modifications, and requested exemptions for Quad Cities Station. We are available for such a meeting at the convenience of your staf f.

One (1) signed original and thirty-nine (39) copies o f this cover letter are provided for your use . Due to their volume, only six (6) copies o f Enclosure A-D a re a ttached.

Please direct any questions you may have concerning these matters to this office, very truly yours, I

W Thoma s J. Rausch Nuclear Licensing Administrator 1m Enclosures cc: Region III Inspector - Qu ad Ci ties 4458N

Enclosure A These responses have been updated to reflect revised shutdown schemes resulting from the associated circuits analysis. Therefore, this information supersedes the responses in our submittals of January 23, ,

1980. February 29, 1980 and June 9, 1980.

Question 8a Description of the systems or portions thereof used to provide ~the shutdown capability and modifications required to achieve the alternate shutdown capability if required.

Response

The descriptions of the systems or portions thereof used to provide the shutdown capability and modifications required to achieve the alternate shutdown capability are discussed for each fire zone in Section 5.0 of the Quad Cities 1 & 2 Fire Protection Associated Circuits Analysis and Modifications Report.

Question 8b System design by drawings which show normal and alternate shutdown control and power circuits, location of components, and that wiring which is in the area and the wiring which is out of the area that required the alternate system.

Response

The locations of components and their control and power circuits are shown by fire zone on Quad Citics drawings ES-148 (Unit 1) and ES-149 (Unit 2). Fire zone drawings are included in the Quad Cities 1 & 2 Fire Protection Associated Circuits Analysis and Modifications Report.

Question 8c Demonstrate 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 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 tne same criteria (FSAR) as other safety related cabinets and panels; to avoid inadvertent isolation from tne control room, the isolation switches should be keylocked, or alarmed in the control room if in the " local" or " isolated" position; periodic cnecks should be made to verify switch is in the proper position for normal operation; and a single transfer switch or other new device should not be a source for a single failure to cause loss of redundant safety systems).

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Response .s.

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All modifications to existing safety systems will meet as'a minimum-the' design criteria and s'tincards in the FSAR. .New isolation-switches- in ..

safetysystemcircuitryWillbekeylocked'or}41armedinthe.controlroom'c

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Demonstrate that wiring, including power sources for ti,e control circuit and equipment operation for the alternake shutdown method, is independsnt of equipment wiring in the area to be avoided!'_,.<

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Response -

All wiring necessary to operate equipment for Uhe alternate shutdow1 .

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methods described in the Quad Cities 1 & 2 Fire Protection Associated Circuits Analysis and Modifications Report will be either independent of wiring in the area to be.-avoided, or separated from redundant wiring in the area in conformance with Section III.G.2 of Appendix R. Control power sources were included in the analysis. -

Question 8e .. _

Demonstrate that alternate shutdown power sources, including all breakers, have isolation devices on control circuits that are routed through the area to be avoided, even.if.the breaker is to be operated manually.

Response -

Isolation will be provided for all alternate shutdown power sources, including the control circuits for necessary breakers.

Question 8f  ;

Demonstrate that licensee procedure (s) have 'veen developed which describe the tasks to be perf ormed to ef f ect the shutdown method. A summary of tnese procedures should be submitted..

Response ,

Tne existing safe shutdown procedures will be modified in accordance with tne shutdown schemes discussed in the Quad Cities-1 & 2 Jire Protection Associated Circuits Analysis and Modifications Report upon receipt of NRC approval for the alternate shutdown method.'

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-Question 8g Demonstrate that. spare fuses are available for control circuits where tnese fuses may be required in supplying power to control circuits used ,

for the shutdown method and may be blown by the effects of a cable spreading room fire. The spare fuses should be located convenient to the existing fuses. The shutdown procedure should inform the operator to 7s. check these fuses.

Response

The Quad Cities 1 & 2 Fire Protection Associated Circuits Analysis and Modifications Report Section 5.14 discusses the alternate shutdown method to be used in case of a fire in the cable room. The alternate shutdown i

method relies on local control of the diesel generator and necessary circuit breakers, local or manual operation of necessary valves, and local monitoring of instrumentation. Since the normal control circuits will be deenergized or locally isolated, replacement fuses are not necessary.

Question 8h Demonstrate that the manpower required to perform the shutdown functions using the procedures of (f) as well as to provide fire brigade members to fight the fire is available as required by the fire brigade technical specifications.

Response ,

Upon receipt of NRC staff approval for the proposed alternate shutdown method, station procedures will be revised in a manner ensuring that the necessary shutdown functiuns can be performed by the available manpower.

Question 81 Demonstrate that adequate acceptance tests are performed. These should verify tnat: equipment operates from the local control station when the transfer or isolation switch is placed in the " local" position and that

the equipment cannot be operated from the control room; and that i equipment operates from the control room but cannot be operated at the local control station when the transfer or isolation switch is in the

" remote" position.

Response

Preoperational tests are performed and documented as part of each modification procedure. The CECO Quality Assurance Program for Fire

' Protection requires tnat tnese preoperational tests be performed before tne equipment is placed into service. These tests are designed to verify tne functional operation of the control circuitry and include verification that the equipment operates from the local control station wnen the isolation device is in the " local" aode. The tests also include verification that the equipment cannot be operated from the control room.

There is not a sound technical basis for disallowing operation from the

" local" control position wnen the isolation device is in the " remote" mode, since the intent of the isolation capability is to ensure that local control is available. .

Question 8j, Technical Specifications of the surveillance requirements and limiting conditions for operation for that equipment not already covered by existing Tech. Specs. For example, if new isolation and control switches are added to a service water system, the existing Tech. Spec.

surveillance requirements on the service water system should add a statement similar to tne following:

"Every third pump test should also verify that the pump starts from the alternate shutdown station after moving all service water system isolation switches to the local control position."

Response

While Technical Specifications should call out the surveillance requirements and intervals, they should not address actions to be taken to carry out those requirements. The best method for describing how a Technical Specification requirement is fulfilled is by Station Procedures. Station Procedures have the flexibility of being upgraded for tne best methods of doing surveillance testing in a timely manner.

Tech Specs require substantial time for upgrading as improvements in metnods of surveillance testing are found.

Question 8k Demonstrate that the systems available are adequate to perform the necessary shutdown functions. The functions required snould be based on previous analyses, if possible (e.g., in the FSAR), such as a loss of normal a.c. power or shutdown on a Group I isolation (BWR). The equipment required for the alternate capability should be tne same or equivalent to that relied on in the above analysis.

Response

The RCIC System design basis is to cool the reactor in the event of isolation from the condenser as discussed in the Quad Cities FSAR. The proposed safe shutdown makeup pump referenced in the Quad Cities Station 1 & 2 Fire Protection Associated Circuits Analysis and Modifications Report will provide shutdown capability equivalent to the RCIC System.

The ability of the RHR System to remove shutdown decay heat is also demonstrated in the FSAR.

Question.81 Demonstrate that repair procedures for cold shutdown systems are developed and material for repairs is maintained on site. .

Response

No need for repairs has been identified in the Quad Cities Cold Shutdown Supplement; therefore, repair procedures are not necessary.

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Enclosure B The following are a summary of responses (dated August 31, 1981, January 29, 1982, and March 16, 1982) to questions lA througn E and 2A through D of enclosure 2 to generic letter 81-12 dated February 20, 1981. .

Question 1.A.

Provide a table that lists all equipment including instrumentation and support system equipment that are required by the alternative or dedicated method of acnieving and maintaining hot shutdown.

Summary of Response In the submittals referenced above, copies of drawings ES-148 and ES-149 were provided. The latest and final revision of these drawings were submitted on March 16, 1982. These drawings listed all equipment including instrumentation and support system equipment required by the alternative method of achieving and maintaining hot shutdown.

Question 1.B.

For each alternative shutdown equipment listed in 1.A above, provide a table tnat lists the essential cables (instrumentation, control and power) tnat are located in the fire area.

Summary of Response The revision of drawings ES-148 and ES-149 submitted on March 16, 1982 nighlighted the essential power, instrumentation, and control cables which were located in the fire zones in which operation of the equipment was considered necessary. All cables appearing in highlighted areas were then listed by fire zone in the Quad Cities 1 & 2 Cable Discrepancy Lists also submitted on March 16, 1982.

Question 1.C.

Provide a table that lists safety related and non-safety related cables associatea with the equipment and cables constituting tne alternative or dedicated method of shutdown that are located in the fire area.

Summary of Response Tne revision of drawings ES-148 and ES-149 submitted on March 16, 1982 referenced (by numbered notes) safety and non-safety related cables associated with equipment and cables considered necessary for the alternative method of shutdown. The cables referenced in the notes are listed in pages 13A through G of ES-148, and pages 9A through G of ES-149. These associated cables are higlighted in fire zones in which proper operation of tne associated essential equipment and cables was considered necessary. All associated cables appearing in highlighted areas were also listed by fire zone in the Quad Cities 1 & 2 Cable Discrepancy Lists submitted on March 16, 1982.

i Question 1.0 Snow that fire-induced failures of the cables listed in 8 and C above aill not prevent operation or cause maloperation of the alternative or -

dedicated shutdown method.

Final Response Approximately 2000 associated and essential cables were identified in this analysis. In the March 16, 1982 submittal, the Quad Cities Station Units 1 & 2 Cable Discrepancy Lists identified approximately 400 pages of cables in which fire-induced failures could prevent operation or cause

maloperation of the identified alternative shutdown metnod for each fire -

zone. Due to the magnitude of problems identified by the associated circuits analysis, new proposed alternative shutdown methods were devised for eacn fire zone. Submitted along with enclosure 8 to this letter are six copies of the Quad Cities Station 1 & 2 Fire Protection Associated Circuits Analysis and Modifications Report. This report discusses the exact alternate safe shutdown method proposed for each fire zone and the modifications requi. red to ensure the availability of that method. The new proposed alternative snutdown methods were chosen in a manner to

resolve all problems identified in the cable discrepancy lists. Revised copies of the cable discrepancy lists indicating those modifications resolving each discrepancy will be submitted by August 16, 1982 to supplement the Analysis and Modifications Report.

Question 1.E l

For each cable listed in 1.8 above, provide detailed electrical schematic drawings that show how each cable is isolated from the fire area.

l Final Response All modifications necessary to comply with item 1.0 above have been descrioed in the Quad Cities Station Fire Protection Associated Circuits Analysis and Modifications Report. Essential cables for the new proposed alternative shutdown methods will be either indepndent of the area to be avoided or will De protected in accordance with Section III.G.2 of Appendix R. The Associated Circuits Analysis and Modifications Report provides sufficient information concerning cable isolation to obtain preliminary NRC approval for the proposed shutdown methods. Upon receipt of preliminary NRC approval of the proposed alternative shutdown methods, detailed electrical schematic drawings necessary for final review will be provided.

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Questions 2.A,B,C.,D A. Identify ece.1 high-low pressure interface that uses redundant electrically controlled devices (such as two series motor operated ..

valves) to isolate or preclude rupture of any primary coolant boundary.

B. Identify the device's essential cabling (power and control) and describe the cable routing (by fire area) from source to termination.

C. Identify eacn location where the identified cables are separated by less than a wall having a three-hour fire rating from cables for the redundant device.

D. For the areas identified in item 2.C above (if any), provide the bases and justification as to the acceptability of the existing design or any proposed modifications.

Summary of Response The only identified high-to-low pressure interface with dual motor operated isolation valves found at Quad Cities Station are located on the Residual Heat Removal System shutdown cooling pump suction lines for each unit. The inboard pump suction isolation valve 1(2)-1001-50 is a 20" normally closed AC motor operated valve on ESF Division I, 480v AC, MCC-18-18. The outboard isolation valve 1(2)-1001-47 is a 20" normally closed DC motor operated valve on ESF Division II, 250v DC, MCC-18.

All essential power and control cables for each valve and the routing for each cable are shown on drawings ES-148, sheet 7F for Unit 1 and ES-149, sheets 4E and 4F for Unit 2. Because of the number of common problems involving tne control cables to these valves, it has been determined that cable separation would be impractical. To maintain the integrity of the high-to-low pressure interface, the normally closed RHR shutdown cooling i valve, M01(2)-1001-47, will be locked in a deenergized position at the l motor control center unless the shutdown cooling system is in service.

This proposed action will be implemented pending final NRC approval of the proposed safe shutdown modifications.

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Enclosure C In response to the Staff position related to source range monitoring external to the control room, it is the position of .

Commonwealtn Edison that such monitoring is not necessary to achieve safe shutdown in tne event of a fire at Quad Cities Station, Units 1 & 2.

This position is based on the fact that it is not credible for a postulated fire to prevent full insertion of all control rods into the reactor core. As it is not possible for the reactor core to became critical at any time after all control rods are inserted, source range monitoring of the core will provide no useful information to the operator. Since no technical justification for the need of source range monitoring has been demonstrated, no further action regarding this matter will be taken.

Enclosure D Exemption In accordance witn 10 CFR 50.12, an exemption is. requested for.

Quad Cities Station, Units 1 & 2 frnm the fixed fire suppression. _. _. _ -

requirement as defined i.1 Section III.G.3.b of Appendix 'R' to 10 CFR 50 in fire zones where alternate shutdown capability is required. That equipment requiring fixed suppression as defined in Section III.G.3.b to whicn an exemption is requested are listed below.

1. All panels located in the control room

2. 4KV SWGR's 13 and 14

3. 480V SWGR's 18 and 19

4. 480V MCC's 18-1A, 18-18, 19-1, 19-4, 19-1-1, 19-6 and 18/19-5

5. 250V MCC's lA and 18

6. 4KV SWGR's 23 and 24 .

7. 480V SWGR's 28 and 29

8. 480V MCC's 28-1A, 28-18, 29-1, 29-1-1, 29-4, 29-6 and 28/29-5

9. 250V MCC 2A and 28 Justification All of the items listed above are critical to the power distribution necessary for normal and emergency operation of safety related equipment for Units 1 and 2. Inadvertant actuation of any fixed water suppression system located over the power distribution equipment listed above could result in tne fault or failure of that equipment. Installation of any other type of fixed suppression system other than water such as cardox, halon, or foam, would be ineffective or inappropriate for the areas in l whicn the equipment listed above are located or for the type of fire l likely to occur in the area. All equipment listed above are in high l

traffic areas wnich are currently provided with fire detection and manual l suppression systems. Furthermore, the existing fire detection and

suppression systems currently installed in the areas containing the i equipment listed above have been reviewed and approved by the NRC in the Quad Cities Station Units 1 & 2 Fire Protection SER. As the probability of inadvertant actuation of a fixed suppression system is of far greater magnitude than the pronability of occurrence of a fire severe enough to require the use of the alternate shutdown method independent of the fire area, Commonwealth Edison feels that the installation of such fixed suppression systems would only result in a decrease in plant safety.

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Exemption 1

In accordance with 10 CFR 50.12, an exemption is requested for fire zones 1.1.1.1 and 1.1.2.1 at Quad Cities Station, Units l & 2 from the 3-hour fire barrier requirement of Section III.G.2.a of Appendix R to 10 CFR 50. These zones are discussed in detail in Sections 5.1 and 5.7 of the Quad Cities 1 & 2 Fire Protection Associated Circuits Analysis and Modifications Report. As stated in the report, a 1-hour fire barrier without fixed suppression is proposed as an alternate to the required 3-hour fire barrier.

Justification Minimal fire loadings in the fire areas are not capable of sustaining a fire of sufficient magnitude or duration to justify the need for a 3-hour i fire barrier. Since cable trays containing essential and associated circuits are above the primary containment suppression pool structure, redundant divis' ions are not susceptable to a single exposure fire.

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