SVP-98-114, Requests Review & Approval to 10CFR50.90 for Unreviewed Safety Question Involving Use of Station Blackout DGs & Use of Mobile Safe Shutdown Batteries in App R Ssd Analysis

Requests Review & Approval to 10CFR50.90 for Unreviewed Safety Question Involving Use of Station Blackout DGs & Use of Mobile Safe Shutdown Batteries in App R Ssd Analysis

ML20216F417
Person / Time
Site:	Quad Cities
Issue date:	03/31/1998
From:	Sager D COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
SVP-98-114, NUDOCS 9804170062
Download: ML20216F417 (22)

Text

i 1 j Commonw ohh i dnon comp.un l ,,, . Qu.id Cnic'. Generaung Mation i m10 bkuh Avenue Nonh i , Coraova. n. <> u mr io I a Tcl wn,u22 u l SVP 98-114 1

March 31,1998 U.S. Nuclear Regulatory Commission Washington D.C. 20555-0001 l

Attention: Document Control Desk

Subject:

Quad Cities Nuclear Power Station Units 1 and 2 Request for NRC Review and Approval Pursuant to 10CFR50.90 for:

Unreviewed Safety Question Involving Use of Station Blackout (SBO) Diesel Generators (DGs) and use of Mobile Safe Shutdown (SSD) Batteries in the Appendix R SSD Analysis NRC Docket Numbers 50-254 and 50-265 Pursuant to 10CFR50.90, Comed requests NRC review and approval for two proposed changes to the Quad Cities fire protection program as described in the Appendix R Safe Shutdown Analysis (SSA) referenced in the Quad Cities Updated Final Analysis Report (UFSAR). While Comed believes these changes represent enhancements to the fire protection program, they have been determined to involve Unreviewed Safety Questions (USQs) pursuant to 10CFR50.59, necessitating NRC review.

The two proposed changes at issue are: (1) use of the Quad Cities Station Blackout (SBO) Diesel Generators (DGs) in lieu of the plant emergency diesel generators (EDGs) to provide the power sources for AC powered equipment required to achieve and maintain post-fire safe shutdown for certain areas requiring alternative shutdown capability; and (2) use of Mobile Safe Shutdown l I

(SSD) batteries in lieu of the station 125 VDC batteries to provide a DC power source for operation of Automatic Depressurization System (ADS) valves necessary to achieve post-fire safe (cold) shutdown for certain areas requidng alternative shutdown capability.

l As was discussed in correspondence to the NRC of January 2,1998, and January 23,1998, Comed has been revising the Appendix R SSA and implementing procedures. The revised SSA ,

supports restart of the two Quad Cities units by providing added confidence that significant fire protection concerns related to shutdown in the event of a fire are adequately addressed. Comed respectfully requests the NRC Staff to review and approve these changes.

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USNRC SVP 98-114 2 March 31,1998 These two changes meet applicable regulatory criteria and offer an overall safety benefit. The determination that the, vvolve USQs is based on conseivative application of the criteria of 10CFR50.59. The U -) for use of the SBO DGs arises from the possibility of a different type of malfunction that is nonetheless determined to involve no significant safety concem. The USQ for use of the mobile SSD batteries arises from a small increase in the probability of a malfunction of equipment important to safety. Both changes arejudged to have little, if any, adverse consequences which are more than compensated by overall reductions in risk associated with the improvements in the Quad Cities Appendix R Safe Shutdown methodology.

The SBO DGs, for example, have greater electrical load capacity than the EDGs presently relied upon, providing greater flexibility in the selection and operation of safe shutdown equipment. The design of the SBO DGs also reduces the potential for spurious actuation leading to autoloading.

Furthermore, the SBO DGs ao located in a building that is physically separated and not subject to damage from a fire which requires plant shutdown. Use of the Mobile SSD Batteries allows simpler required actions to open the ADS valves.

These changes are also integral to an overall improved approach to Appendix R compliance for Quad Cities. The revised SSA and implementing procedures will include many enhancements, including human factors improvements to procedures, such as individual procedure tables, inclusion of recovery steps to verify critical lineups, and use of an EOP-like flowchart to guide the unit supervisor. In total, the aspects of the proposed changes determined to involve USQs reflect only a narrow component of the changes - and indeed, a narrow component of the entire revised fire protection program - that will in the aggregate substantially improve the plant's ability to achieve and maintain safe shutdown in the event of a fire. Because the two changes are in full compliance with applicable NRC regulations, Quad Cities is not preparing additional compensatory measures for safe operation pending NRC review and approval of this request.

The following Attachments have been developed in support of this proposed change:

Attachment A Description and Safety Analysis for Use of the SBO DGs in the SSA Attachment B Description and Safety Analysis for Use of the Mobile SSD Batteries in the SSA Attachment C Evaluation of Significant Hazards Consideration for Use of SBO DGs Attachment D Evaluation of Significant Hazards Consideration for Use ofMobile SSD Batteries Attachment E Environmental Assessment Statement

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USNRC SVP 98-114 3 March 31,1998 The request for the proposed changes have been reviewed and approved by Comed Onsite and Offsite Review functions in accordance with Comed procedures and policies. Comed has reviewed the proposed changes in accordance with 10CFR50.92(c) and has determined that no significant hazards consideration exists. Comed requests NRC review and approval of the proposed changes within 60 days.

Further specific changes to the plant or procedures that result from review and implementation of the revised SSA will be evaluated, as identified, under 10CFR50.59.

To the best of my knowledge and belief, the statements contained herein are true and correct. In some respects these statements are not based on my personnel knowledge, but contain information furnished by other Comed employees, contractor personnel and consultants. Such '

information has been reviewed in accordance witn company practice, and I believe it to be reliable.

Comed is notifying the State ofIllinois of this application by transmitting a copy of this letter and its attachments to the designated state official.

If you have any questions concerning this letter, please contact Charles Peterson, Regulatory Affairs Manager, at (309) 654-2241, extension 3609.

Respectfully, David A. Lger Site Vice iesident Quad Citi Station Subscribed and Sworn to before me on this / day of AFR,L

,1998.

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USNRC SVP 98-114 4 March 31,1998 Attachments: Attachment A Description and Safety Analysis for Use of the SBO DGs in the SSA Attachment B Description and Safety Analysis for Use of the Mobile SSD Batteries in the SSA Attachment C Evaluation of Significant Hazards Consideration for Use of SBO DGs Attachment D Evaluation of Significant Hazards Consideration for Use ofMobile SSD Batteries Attachment E Environmental Assessment Statement cc: A. B. Beach, Regional Administrator, Region III R. M. Pulsifer, Project Manager, NRR C. G. Miller, Senior Resident Inspector, Quad Cities W. D. Leech, MidAmerican Energy Company D. C. Tubbs, MidAmerican Energy Company F. A. Spangenberg, Regulatory Affairs Manager, Dresden INPO Records Center Office of Nuclear Facility Safety, IDNS DCD License (both electronic and hard copies)

M. E. Wagner, Licensing, Comed SVP Letter File f

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ATTACHMENT A SVP 98-114 DESCRIPTION AND SAFETY ANALYSIS FOR USE OF THE STATION BLACKOUT DIESEL GENERATORS IN THE 10CFR50, APPENDIX R, SAFE SHUTDOWN ANALYSIS (PAGE 1 of 7)

Introduction /Pronosed Channe The Quad Cities fire protection program currently relies on the Emergency Diesel Generators (EDGs) as the onsite AC power source for equipment utilized to achieve and maintain Appendix R post fire safe shutdown. The proposed fire protection program change involves using the Station Blackout (SBO) diesel generators (DGs) in lieu of the EDGs for a fire in areas requiring alternative shutdown capability.

The change will be documented in the Safe Shutdown Report (Fire Protection Reports, Volume 2), which is incorporated by reference in Section 9.5 of the Quad Cities Updated Final Safety Analysis Report (UFSAR). The EDGs will continue to be the onsite AC power source for a fire in areas not requiring alternative shutdown capability.

For fires in areas which require the use of alternative shutdown, the SBO DGs are preferred over the EDGs for several reasons and result in several improvements to the Quad Cities fire protection program, including:

• The SBO DGs are located in their own building. This building is physically separate from other areas of the plant that contain other safe shutdown equipment.

• The SBO DG's 125 VDC system and other auxiliaries are located at the SBO DG building.

Consequently, they are not subject to damage from a fire that would require plant shutdown.

• The SBO DGs have a greater electrical load capacity than the EDGs. The greater capacity provides greater flexibility in the selection and operation of safe shutdown equipment. As a result, several manual actions that are now required to use the EDGs can be eliminated.

• Access to the physically separate SBO DG building is from the outside, so it can be reached during a fire which requires plant shutdown.

c A fire in the SBO DG building is isolated and does not require plant shutdown.

The use of the SBO DGs to provide on-site AC power for equipment utilized for post-fire safe shutdown in areas requiring alternative shutdown is in conformance with 10CFR50, Appendix R. The SBO DGs are not required to be safety-related or single failure proof. They are covered by a maintenance program, described below, to assure their reliability and availability.

ATTACHMENT A SVP 98-114 DESCRIPTION AND SAFETY ANALYSIS FOR USE OF THE STATION BLACKOUT DIESEL GENERATORS IN THE 10CFR50, APPENDIX R, SAFE SHUTDOWN ANALYSIS (PAGE 2 of 7)

Descrintion of SBO DGs The SBO system is a non-class IE, independent source of additional onsite emergency AC power for meeting the Station Tdackout rule (10CFR50.63). The system consists of two diesel-driven generator sets, each having a continuous rating of 4350 kW at 4160 V at a pswer factor of 0.8. The 2000-hour / year rating is 4785 kW Each generator is connectable, but not normally connected, to the safe shutdown equipment on one nuclear unit, but can also be connected to the opposite unit via the safety-related 4 kV cross-ties. The SBO DGs must be manually started and manually connected to the appropriate safe shutdown loads. The SBO DG buses are connected to the same buses as the EDGs.

Motive power for the SBO DG is supplied by tandem (12 cylinder and 16 cylinder engines on a common shaR with the generator located in the middle) turbocharged fuel-injected Electro-Motive Division (EMD) 645F4B diesel engines. A Woodward 2301 A series electronic governor with actuators is used on each diesel and is set to maintain a constant 900 rpm.

The physical location of the SBO DGs makes them readily accessible and appropiiate as a source of power for safe Autdown in the event of a fire requiring alternate shutdown capability. The SBO DGs and auxiliaries are located in the Station Blackout Building. This building provides physical isolation from safety-related systems and components. Each SBO DG is physically separated from the mher within the building. The SBO building is also p;ovided with fire detection / suppression, heating, ventilation, air conditioning, drain systems, and normal and emergency lighting.

The SBO DGs would be started and loaded locally in the SBO DG building for a fire scenario.

< In this mode ofoperation, the control room functions are isolated to prevent fire induced spurious operations from affecting the operation of the diesels. In the event of a fire, the SBO DGs may spuriously start because of a short or hot short in the control circuits in the control room. In

, accordance with the proposed change to the Safe Shutdown Analysis, an operator will report to the SBO DG building to isolate the SBO DGs from the control room if they have spuriously started. In the event of a spurious start, the SBO DGs can operate for at least an hour without the AC powered auxiliaries. ARer verification of offsite power, the DGs can be : hut down.

The remote SBO DG contrcis and metering in the control room are connected to the SBO DGs through the Distributed Control System (DCS). This system is powered from the SBO DG uninteruptable power system (UPS) panels located in the SBO building. The following control .

room functions are isolated from the SBO DG building by de-energizing the DCS panels and placing the LOCKOUT / REMOTE /LOCAIJPLC BYPASS selector switch in the LOCAL porition: emergency stop, stop/ start, voltage control, governor control, fuel oil transfer functions, 4kV circuit control logic and metering. After being isolated from the control room, the SBO DGs can be started and controlled from the SBO building.

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ATTACHMENT A l SVP 98-114 DESCRIPTION AND SAFETY ANALYSIS FOR USE OF THE STATION BLACKOUT DIESEL GENERATORS IN THE 10CFR50, APPENDIX R, SAFE SHUTDOWN ANALYSIS (PAGE 3 of 7)

Instrumentation and inetering is available and functional in the SBO DG building. Day tank level is available from mechanical gauges mounted on the day tanks.

In addition to its own lighting system powered from the SBO DGs, 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> emergency lights are provided to aid the operator in isolating and starting the SBO DGs.

The fuel oil day tanks are sized for four hours of SBO DG operation. The day tanks can be filled from a 15,000 gallon underground storage tank, utilizing the transfer pumps. The fuel oil transfer pumps are operated using a switch to defeat the DCS signal previously de-energized to isolate the spurious operations in the control room. Day tank level is observed while making this fuel transfer.

Each SBO DG has its own 125 VDC battery system that is separate from the station's 125 VDC battery system. Any part of the 125 SBO VDC system cabling that is routed outside of the SBO building is either protected by fuses to isolate on a fire induced fault or the cable is routed in fire areas where the associated SBO DG is not required for safe shutdown.

Safety Basis for Proposed Channe Comed proposes to modify the Appendix R Safe Shutdown Analysis (SSA) as documented in the Safe Shutdown Report to use the SBO 4Gs in lieu of the EDGs as the onsite AC power source for equipinent necessary to achieve and maintair. post-fire safe shutdown in areas requiring alternative chutdown capability. The SBO DGs are preferred over the EDGs as the on-site AC power source for post-fire safe shutdowran areas requiring alternative shutdown because they have greater capacity, are located in a separate building with outside access, and are physically separate from other areas of the plant which contain equipment necessary for post-fire safe shutdown. Consequently, a fire in the SBO DG building does not require unit shutdown and a fire in another fire area requiring alternative shutdown capability does not preclude use of the SBO DGs as the onsite AC power source.

Anvendix R Reauirements For use in this capacity, the SBO DGs satisfy the regulatory requirements of Appendix R. The SBO DGs are physically separate from the postulated fire, and both the SBO DGs and associated equipment will not be damaged by the postulated fire. They will be capable of providing onsite AC power for all equipment m> y to achieve and maintain safe post-fire shutdown for the required 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. This includes the

! ability to power systems and equipment necessary to :

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• Maintain the reactor coolant inventory; l e Achieve and maintain hot shutdown;

• Achieve and maintain cold shutdown within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

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l ATTACIIMENT A l SVP 98-114 i l -

DESCRIPTION AND SAFETY ANALYSIS FOR USE OF THE STATION BLACKOUT DIESEL GENERATORS i IN THE 10CFR50, APPENDIX R, SAFE SIIUTDOWN ANALYSIS l (PAGE 4 of 7) l l

In addition, the capability exists to monitor process veiables to perform and control the above  ;

functions. l There is no need for the SBO DGs to satisfy Class IE criteria, be single failure proof, or satisfy seismic criteria. 10CFR50, Appendix R, paragraph L.6 states that " . . . shutdown systems installed to ensure postfire shutdown capability need not be designed to meet seismic Category I criteria, single failure l criteria, or oi:r design basis accident criteria, except where required for other reasons, e.g., because of interface with or impact on existing safety systems, or because of adverse valve actions due to fire l damage."

Impact onJBO Function l l

The use of the SBO DGs for safe shutdown in the event of a fire does not adversely affect the ability of l the SBO DGs to satisfy Station Blackout requirements (10CFR50.63). The physical connection of the SBO DGs to the plant electrical buses is not altered. Rerouting of certain control and power cables has .

been performed to avoid fire related damage to the circuits associated with more than one SBO DG. l There is no impact on the plant's response to other non-fire design basis events. The use of the SBO l DGs is not credited in the UFSAR Chapter 15 accident analysis. Consideration of an independent occurrence of another design basis accident during an Appendix R fire event is not required.

Manual Startuo In the event of a fire which results in the need for onsite power to achieve and maintain post-fire safe shutdown in areas requiring alternative shutdown capability, the SBO DGs are manually started from the local control panel in the SBO Building. The SBO DGs are then manually aligned to the Essential Service (ESS) 4 kV buses.

In the safety evaluation pursuant to 10CFR50.59, the change from the automatic start capability of the EDGs to the manual start of the SBO DGs was determined to involve the possibility of a new malfunction. However, from a safety perspective, Comed has concluded that this possibility is small, that reasonable assurance of safety would exist, and that the overall benefits of the proposed change outweigh the difference from the current situation.

Automatic starting of the onsite AC power source is not required by 10CFR Appendix R. ManuA starting can be accomplished within 10 minutes, which is consistent with the assumptions in boto the current SSA and the revised SSA for availability of the ensite AC power source for fire areas l requiring alternate shutdown capability. The actions needed to manually start the SBO DGs do l

not involve unusual or complicated alignments of power or fluid systems, and there are no complex sequencing of actions required for proper operation. These actions are included in operator training on the operation of the SBO DGs. The lack of automatic load features reduces any concern that the generators spuriously load to a live bus.

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ATTACIIMENT A SVP 98-114 1 DESCRIPTION AND SAFETY ANALYSIS FOR USE OF THE

, STATION BLACKOUT DIESEL GENERATORS

! IN THE 10CFR50, APPENDIX R, SAFE SHUTDOWN ANALYSIS (PAGE 5 of 7) l Moreover, other manual actions which were needed to use the EDGs for Appendix R safe shutdown have been reduced due to the greater flexibility in safe shutdown equipment made possible by the greater power output of the SBO DGs. The greater output results in fewer i manual actions to limit electrical loads supplied by the onsite AC power source. Therefore, even though the manual actions necessary to use the SBO DGs introduce a small, potential increased possibility for error in establishing onsite power in the event offsite power is not available, that

potential for erro. is offset by elimination of manual actions associated with the use of the EDGs.

l l Reliability and Availability The SBO DGs are included under Comed's Augmented Quality Standard. A discussion of the augmented quality standard is described in the Comed Quality Assurance Program Topical Report CE-1-A. Surveillance Requirements have been developed for the SBO DGs and include l the following tests:

Procedure. No. Procedure Title Frequency QCOS 6620-01 SBO DG 1(2) QUARTERLY LOAD TEST Quarterly QCOS 6620-02 SBO DG 1(2) DC LUBE OIL CIRCULATING PUMP Quarterly l QUARTERLY TEST

QCOS 6620-03 SBO DG 1(2) STARTING AIR COMPRESSOR Quarterly l QUARTERLY TEST l QCOS 6620-04 SBO DG 1(2) JACKET WATER BOOSTER PUMP Quarterly QUARTERLY TEST QCOS 6620-05 SBO DG 1(2) FUEL OIL TRANSFER PUMP Quarterly l

l QUARTERLY TEST l QCOS 6620-06 SBO DG 1(2) FUEL OIL DAY TANK Quarterly i ACCUMULATED WATER QUARTERLY l l DRAINING l QCOS 6620-10 SBO DG 1(2) SESQUIANNUAL 18 month l ENDURANCE / MARGIN AND FULL LOAD REJECT TEST QCOS 6620-11 SBO DG 1(2) SEMI-ANNUAL 6 month REMOTE /LOCAUPLC BYPASS EMERGENCY START TEST QCOS 6620-12 SBO DG 1(2) SESQUIANNUAL OVERSPEED TRIP 18 month TEST QCOS 6620-13 SBO DG 1(2) SYNCHRONIZING / RESTORATION 10 years TEST QCOS 6620-14 SBO DG 1(2) JACKET WATER BOOSTER PUMP 18 month RECIRC VALVE SESQUIANNUAL PRESSURE CONTROL TEST

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ATTACHMENT A SVP 98-114 DESCRIPTION AND SAFETY ANALYSIS FOR USE OF THE STATION ' BLACKOUT DIESEL GENERATORS i IN THE 10CFR50, APPENDIX R, SAFE SHUTDOWN ANALYSIS (PAGE 6 of 7) i The SBO DGs are included within the scope of the Maintenance Rule Program. Recently obtained reliability data indicate the SBO DGs meet the established reliability goal of 95%. i However, the SBO DGs are currently classified as a Maintenance Rule (a)(1) system until full l implementation of the short term and the long term Preventive Maintenance (PM) program. This l classification as an (a)(1) system subjects the system to greater attention and increased l monitoring. The (a)(1) action plan for the SBO DGs requires determining the appropriate PM program, as well as implementing the short term PM and the long term PM program.

Quad Cities operating experience indicate the SBO DGs currently meet the established reliability goal of 95% for Station Blackout (10CFR50.63), which is the same as the established reliability l goal for the EDGs. The outage time for an SBO DG is administratively controlled to ensure j availability goals are met. Based collectively on the requirements associated with the augmented l l

quality classification, appropriate surveillance requirements, current and developing PM requirements, and the demonstrated reliability of the SBO DGs, Comed concludes there is i reasonable assurs.nce that the SBO DGs will supply AC power as required for equipment l necessary to achieve and maintain post-fire safe shutdown in areas requiring alternative shutdown capability, l Another advantage of the SBO DGs as compared with the EDGs is that tb SBO DGs are more l tolerant of starts without concurrent operation of their auxiliaries resulting tron. fre related control circuit damage. If the SBO DGs start without their auxiliaries, calculations have determined that the units can operate for at least one hour without damage. By comparison, for the EDGs, less than 10 minutes may be available prior to damage for the EDGs starting without their auxiliaries. This one hour provides more than adequate time to respond and either shut down the spuriously started SBO DGs or start required auxiliaries. The additional duration for operation of the SBO DGs result from their design. The SBO DGs must be manually connected to the ESS buses followed by manual loading of the ESS bu. Therefore, spurious starting of the SBO DGs result in their operation at a no load condition.

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A'ITACHMENT A SVP 98-114 DESCRIPTION AND SAFETY ANALYSIS FOR USE OF THE STATION BLACKOUT DIESEL GENERATORS .

IN THE 10CFR50, APPENDIX R, SAFE SHUTDOWN ANALYSIS I (PAGE 7 of 7) l Fuel Consumption At rated power there is sufficient fuel for operation of both SBO DGs for approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

In the safety evaluation pursuant to 10 CFR 50.59, the potential for fuel transfer to replenish the SBO DG fuel supply was found to involve the possibility of a new malfunction for equipment important to safety. However, from a safety perspective, Comed has concluded that this possibility is remote, that reasonable assurance of safety would exist, and that the overall benefits of the change outweigh the difference from the current situation.

Additional diesel fuel is available onsite in the fuel oil storage tanks for the Unit 1, Unit 2 and Unit 1/2 EDG. The capability exists to transfer fuel oil to the SBO DG storage tank from the three EDG storage tanks using temporary hoses and a portable gasoline powered pump. This will provide for at least 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of operation of the SBO DGs using DG fuel available onsite.

Delivery of additional fuel from offsite can be accomplished within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Diversion of the liXi fuel oil supply to the SBO DGs is consistent with the revised SS A because the EDGs are not required for any other purpose during a fire for which the SBO DGs are relied upon to achieve post-fire safe shutdown.

The manual actions necessary to transfer fuel from the EDG storage tanks to the SBO DG storage l tank are not difficult or complex. The manual actions include positioning a portable pump near the EDG fuel oil storage tank, placing the suction hose in the EDG fuel storage tank, running the discharge hose from the portable pump to the SBO fuel oil storage tank, and starting a gasoline i powered portable pump. A procedure will be developed to ensure proper control of these actions  !

prior to startup. The process and equipment involved also have been previously used for transferring fuel oil between underground tanks.

Sufficient fuel for the portable pump is maintained onsite to operate the pump for greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> although pump operation for this duration is not required. The capacity of the portable pump is well in excess of that required to transfer fuel to operate the SBO DGs at " v% load. As a result the portable pump will need to operate for less than 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> to transfer the necessary quantity of fuel oil to the SBO DG fuel oil storage tank. Based on the relative simplicity of the actions and onsite availability of required equipment and supplies, Comed concludes there is reasonable assurance the manual actions necessary to transfer fuel to the SBO DG fuel oil storage tank can be accomplished.

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SVP 98-114 DESCRIPTION AND SAFETY ANALYSIS FOR USE OF THE MOBILE SAFE SHUTDOWN BA'ITERIES IN THE 10CFR50, APPENDIX R, SAFE SHUTDOWN ANALYSIS (PAGE 1 of 4)

Introduction /Pronosed Channe l

The 125 VDC power to the Automatic Depressurization System (ADS) valves is vulnerable to postulated i fire damage. The Appendix R Safe Shutdown Report (SSR) identifies a repair to provide alternative l power to operate the ADS valves to achieve low pressure shutdown cooling and cold shutdown in certain i fire scenarios. The proposed change inwNes the use of mobile Safe Shutdown (SSD) batteries instead of the station batteries to operate the AD.? alves from outside the control room in these scenarios.

The need for a capability to supply power to the ADS valves from outside the control room arises as fohows. The ADS relief valves are actuated by DC powered solenoid valves located inside the primary containment (the drywell). For certain Appendix R alternate shutdown fire scenarios, cables located outside primary containment and powering these solenoids may be damaged and require an alternate ,

source of 125 VDC power. Under this condition, plant procedures support local actuation of these i valves in order to initiate RHR shutdown cooling. I Currently, the action to use the ADS valves to achieve cold shutdown includes a proceduralized installation of a temporaryjumper between the station 125 VDC power supply and electrical terminations (or conductors if a panel is not available) near the primary containment boundary to power the ADS i solenoid valves. This action enables operation of two ADS relief valves following the Appendix R alternate shutdown fire to carefully reduce reactor pressure and permit use of the Residut! Heat Removal System in the shutdcwn cooling (SDC) mode. Although this approach to use the 125 VDC station supply for achieving cold shutdown could be maintained, Comed has dete.rmined that an alternative source of power which already is in the plant for other reasons would be preferable.

Comed proposes to use the two existing mobile SSD power supplies (one for each unit) currently in place to support alternate shutdown under the Interim Alternate St.utdown Method (IASM). IASM is an interim Individual Plant Examination of External Events (IPEEE) risk reduction strategy for providing core cooling in the highly unlikely event that other safe shutdown systems are unavailable or ineffective.

The IASM methodology provides a similar alternative approach to depressurizing the reactor via ADS blowdown using these mobile 125 VDC batteries. Under the proposal, the mobile safe shutdown batteries would also be used to support the safe shutdown analysis for Appendix R alternate shutdown.

Because the two scenarios are neither simultaneous nor sequential, use of the mobile SSD batteries for Appendix R events would not conflict with the potential IASM use. Depressurization, and therefore loading of the mobile SSD batteries, will occur for only one scenario.

No other changes would be made to the operation of the ADS valves as described in the Quad Cities l

Appendix R Safe Shutdown Report (Fire Protection Reports, FPR Volume 2), which is incorporated by reference into Section 9.5 of the Updated Final Safety Analysis Report (UFSAR). The ADS valves would continue to be operated manually in order to depre aue the reactor coolant system where low pressure shutdown cooling is necessary to achieve and mJntain coM shutdown conditiom, within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

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1 l ATTACHMENT B SVP 98-114 i DESCRIPTION AND SAFETY ANALYSIS FOR l USE OF THE MOBILE SAF. SHUTDOWN BATTERIES IN THE 10CFR50, APPINDIX R, SAFE SHUTDOWN ANALYSIS (PAGE 2 of 4)

Description of Mobile 125 VDC Batteries The mobile SSD batteries are staged on the 623' elevation of each reactor building - the same elevation as ADS blowdown panels 2201(2)-32. This is an area normally accessible to plant equipment operators.

Connection of the 125 VDC power supplies at the ADS blowdown panels is the preferred location for manual actuation of the ADS valves from outside the main control room.

Use of either of the two (duplicate and redundant) mobile safe shutdown batteries simplifies operator actions in meeting the shutdown function. By being mobile, the power supplies can be transported and located immediately adjacent to the ADS control panel, thereby eliminating the need to connect long power cables to a distribution location for the station 125 VDC batteries. Use of the mobile power sources also reduces the potential for human error in making connections and valve actuation because the conductors a.nd terminal points are labeled and color coded. The carts are also equipped with switches which simplify the final energization or de-energization of circuits.

Safety Basis for Proposed Channe The current Appendix R Safe Shutdown Report, incorporated by reference into the UFSAR, provides for the manual depressuization of the reactor to facilitate achievement of cold shutdown. Appendix R to 10CFR50 requires that cold shutdown be achieved within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of the initiating event. Under the plant Safe ShuMown Analysis (SSA), normal power circuitry to the relief valves is considered unavailable. Timfore, to accomplish depressurization, temporary installation of multi-conductor jumper cables is necessary to supply power from the station 125 volt batteries to actuate the ADS solenoid valves. This is considered a co!d shutdown repair for the purpose of achieving reactor depressurization ,

1 to permit low pressure RHR shutdown cooling, but is acceptable under Appendix R requirements.

Safety Benefits The proposed change is an improved methodology for implementing a cold shutdown repair to enable  :

ADS valve operation following an Appendix R alternate shutdown fire. Instead of repairing the power cables to the ADS solenoid valves by supplying power from the station batteries, the valves would be ,

powered from the mobile SSD batteries. Since a similar procedure for actuating ADS solenoid valves by j using the mobile SSD batteries is already in place for the Interim Alternate Shutdown Method (IASM),

procedures and operator readiness are enhanced by adopting a common methodology.

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ATTACilMENT B SVP 98-114 DESCRIPTION AND SAFETY ANALYSIS FOR USE OF THE MOBILE SAFE SIIUTDOWN BNITERIES IN THE 10CFR50, APPENDIX R, SAFE SilUTDOWN ANALYSIS (PAGE 3 of 4)

Several features of the proposed alternative simplify the cold shutdown repair activities, thus enhancing safety. The principal advantages for this change relate to improvements in regards to:

. There are two, dedicated power supplies (only one is needed; one may be assumed damaged by fire).

e The use of common methodologies for Appendix R alternate shutdown and IPEEE /IASM scerarios to actuate ADS reliefvalves enhances operator readiness.

. There are improved human engineering features of the power supplies - such as the labeling and color coding of the conductor and terminal points - reducing the potential for human error, providing ease of use, and enhancing personnel safety.

Each of these advantages improves overall plant safety.

I Reliability and Availability The statico batteries are safety-related Class IE equipment and are subject to commensurate maintmance and surveillance requirements. The non-safety-related mobile SSD batteries are currently classified as a Maintenance Rule (a)(1) system, subject to heightened attention, increased monitoring, and an action plan to establish short term and long term Preventive Maintenance (PM) requirements. A PM program is being developed for the mobile SSD batteries. Currently, the batteries are checked for voltage on regular operator rounds, and will be discharge tested on a nominal 18-month frequency. The mobile SSD batteries and associated chargers were successfully tested in accordance with station acceptance test procedures for electrical modifications, including discharge testing. The mobile SSD batteries are also classified . nd adhere to Augmented Quality Standards per Comed Quality Assurance Program Topical l Report CE-1-A.

The two mobile SSD batteries each consist of twenty 12-VDC batteries, consisting of two strings of ten batteries connected in parallel to obtain a nominal 125 volt battey. They are sealed cell, lead acid batteries. Battery sizing is in accordance with the methodology ofIEEE 485-1983. Each batten is designed to operate between 105 and 140 VDC and has sufficient capacity to maintain the minimum acceptable terminal voltage while supporting the duty cycle (including applicable coriection factors for aging, design margin, and ambient temperature). If the Appendix R alternate shutdown fire is located in one unit's reactor building and availability of that unit's safe shutdown battery is nrohibited, vessel blowdown can still be achieved by using the other dedicated mobile SSD batten.

Use of the mobile safe shutdown batteries is preferred over the use of the station batteries. Their use reduces the need for long lengths of cable (approximately 20' vs. approximately 300') and reduces loading of the station batteries during this period of questionable availability. The mobile SSD batteries offer positive safety features due to their redundancy, simplicity, and ease of use. The mobile power supplies will be staged in separate fire zones (one in each reactor building) thus ensuring availability afler an Appendix R alternate shutdown fire.

f ATTACllMENT B l SVP 98-114 l DESCRIPTION AND SAFETY ANALYSIS FOR l USE OF TIIE MOBILE SAFE SIIUTDOWN BATTERIES l l IN TIIE 10CFR50, APPENDIX R, SAFE SIIUTDOWN ANALYSIS l l (PAGE 4 of 4) 1 Responding to the postulated Appendix R alternate shutdown fire, the batteries will be re-positioned to l facilitate connection to the appropriate terminals. Since this is an action to support achieving cold j shutdown, use of the mobile SSD batteries may occur many hours after the initiating event, but in sufficient time to achieve cold shutdown within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> per Appendix R.

l At the ADS blowdown panel, the operator will manually lift and land leads using color coded conductors

! and terminal blocks. Individual disconnect switches on the mobile battery cart are operated to actuate the 1 1 ADS valve solenoids, opening the relief valves to depressurize the reactor pressure vessel. For the  !

Appendix R alternate shutdown fire, two relief valves will be opened, but not concurrently, to blowdown the reactor. Alternating between two valves during the blowdown sequence provides more uniform temperature distribution within the suppression pool.

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In the unlikely event that the ADS blowdown panel is not available or damaged, temporary jumper cables will be used to connect the mobile safe shutdown batteries to the ADS solenoids at a drywell penetration. Thesejumper cables are approximately 300 feet in length and provide ,

another alternative location for connecting power to the ADS valves.

Battery Testing l

! Although there are many positive aspects to the proposed change as discussed above, in the safety evaluation pursuant to 10CFR50.59 the change to utilize the mobile SSD batteries was determined to involve a small increase in the probability of a malfunction adversely affecting the ability to achieve and l maintain safe shutdown. The mobile SSD batteries are maintenance free batteries and do not permit l surveillance of battery electrolyte. Consequently, the use of the mobile SSD batteries in lieu of the j station batteries could potentially increase the probability of an equipment malfunction. However, l Comed has concluded that the use of the mobile SSD batteries is adequate for compliance with Appendix R and provides reasonable assurance that safe shutdown can be achieved and maintained.

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ATTACHMENT C SVP 98-il4 NO SIGNIFICANT H.AZARDS CONSIDERATION EVALUATION FOR USE OF THE STATION BLACKOUT DIESEL GENERATORS (PAGE 1 of 3) l 4

No Sinnificant Hazards Consideration l

The Commission has provided standards for determining whether a significant hazards consideration exists as stated in 10CFR50.92(c). A proposed amendment to an operating license or unreviewed safety question does not involve a significant hazards consideration if operation of the facility in accordance with the proposed change would not: (1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety.

Comed has evaluated the proposed use of the SBO DGs to r,rovide the power source for equipment needed to achieve and maintain safe shutdown fr.r an Appendix R fire and determined that it does not involve a significant hazards consideration ihr the reasons discussed below.

1) No significant increase in the probability or consequences of an accident previously evaluated is involved because of the following:

l Two types of previously evaluated accidents are relevant to this criterion: (1) a fire; I (2) other accident evaluated in the UFSAR. For these previously evaluated accidents, the change would not result in an increase in either their probabilities of occurrence or the -

consequences of their occurrence, for the following reasons the use of the SBO DGs in lieu of the EDGs does not change the probability or consequences of a fire. The likelihood of a fire is unchanged. Use of the SBO DGs does not significantly change the fire loading nor introduce significant new ignitioa sources.

The consequences of a fire are unchanged because use of the SBO DGs continues to support the station's ability to achieve and mair.tain shutdown in the event of a fire.

Use of the SBO DGs for non-fire purposes is unchanged by use of the SBO DGs for post-fire safe shutdown in the event of a fire in areas requiring alternate shutdown capability.

Accordingly there is no change in the probability or consequences of a previously evaluated accident involving the SBO DGs. Similarly, there is no change to the probr.bility or consequences of other accidents that have been previously evaluated because they are independent of this change in use of the SBO DGs.

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ATTACIIMENT C SVP 98-II4 i

NO SIGNIFICANT IIAZARDS CONSIDERATION EVALUATION FOR USE OF TIIE STATION BLACKOUT DIESEL GENERATORS (PAGE 2 of 3)

2) The possibility of a new or different kind of accident from any accident previously evaluated is not created because:

The proposed change does not create the possibility of a new or different kind of accident from that previously evaluated for Quad Station. Although the SBO DGs will be used for a new function, there is no significant change in the operation of the SBOs for a non-fire event. Moreover, the overall use of the SBO DGs as an AC power source is not significantly different from the use of the EDGs. The SBO DGs buses provide power to the same buses that are powered from the EDGs. No new modes of operation are introduced by the proposed changes. The use of the SBO DGs provides a slightly different but effective method for achieving and maintaining post-fire safe shutdown for .

areas requiring alternate shutdown capability. As such, the proposed change does not l create the possibility of a new or different kind of accident. {

3) No significant reduction in the margin of safety is involved because:

A change in the fire protection program does not result in a significant reduction in the margin of safety if the change does not result in a significant adverse impact on the plant's l ability to achieve and maintain safe shutdown in the event of a fire. The proposed use of the SBO DGs instead of the EDGs to achieve and maintain safe shutdown within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> change does not significantly affect the capability or reliability of the equipment assumed to operate in the safety analysis. ,

I The demonstrated capability and reliability of the SBO and EDGs are not sigrJficantly different. Indeed, the SBO DGs represent a safety improvement due to their physical separation from the postulated fire areas, and the operational benefits provided by their greater capacity. Any narrow reduction in margin associated with the need to manually start the SBO DGs is offset by the reduction in manual actions necessary to reduce electricalloads powered from the EDGs. The lack of Class 1E qualification for the SBO DGs is not significant from a safety perspective because the demonstrated reliability of the SBO DGs is comparable to the reliability of the EDGs. The lack of seismic qualification and single failure protection do not constitute a significant reduction in margin since neither of these attributes is required by Appendix R. Accordingly, the Commission has already determined that these attributes are not part of the Appendix R acceptance criterion. Any reduction in margin associated with the greater fuel consumption rate of the SBO DGs is partially offset by the increased flexibility in powering equipment to achieve and maintain post fire safe shutdown. Additionally, onsite fuel storage and manual l transfer capabilities provide for at least 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of SBO DG operation. Within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, deliveries of diesel fuel from offsite supplies is expected. Therefore, the use of the SBO DGs as an onsite AC power source for equipment necessary to achieve ud maintain post-fire safe shutdown in areas requiring alternate capabilities does not involve a significant reduction in margin.

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1 f 1 ATTACHMENT C f SVP 98-114 I -

NO SIGNIFICANT HAZARDS CONSIDERATION EVALUATION FOR USE OF THE STATION BLACKOUT DIESEL GENERATORS (PAGE 3 of 3) l The NRC has provided guidance for the application of the significant hazards considerations standards in Final Rule, " Final Procedures and Standards on No Significant Hazard Considerations," SIFR7744. This document provides examples of changes which 1 are and are not considered likely to involve significant hazards considerations. This proposed change does not involve a significant relaxation of the criteria used to establish safety limits, a significant relaxation of the bases for the limiting safety system settings, or a significant relaxation of the bases for the limiting conditions for operations. Therefore, based on the guidance provided in the Federal Register and the criteria established in 10CFR50.92(c), the proposed change does not involve a significant hazards consideration.

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ATTACliMENT D SVP 98-114 NO SIGNIFICANT IIAZARDS CONSIDERATION EVALUATION FOR USE OF TIIE MOBILE SSD BATTERIES PAGE 1 of 3 No Sinnificant Hazards Consideration i

The Commission's criteria for this evaluation have already been discussed in Attachment C and l will not be repeated here. Comed has evaluated the proposed use of the mobile SSD batteries to j provide the power source for the ADS valves under certain scenarios where the valves are needed to achieve cold shutdown and determined that it does not involve a significant hazards consideration for the reasons discussed below.

1) No significant increase in the probability or consequences of an accident previously evaluated is involved.

l The accident previously evaluated is the postulated fire requiring alternate shutdown l capability. The probability of a previously evaluated fire is not increased significantly because the mobile SSD batteries do not create significant new ignition sources or any other fire initiators. The consequences of a previously evaluated fire are not increased significantly because the mobile SSD batteries do not significantly increase the fire loading in the plant, do not interfere with the plant's ability to extinguish a fire, and are fully capable of fulfilling the designed safety function.

The associated systems related to this proposed change are not affected in a way that could impact the initiation of any accident sequence for the Quad Cities Station. No modes of operation are introduced by the proposed change such that adverse consequences result.

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The probability of an accident involving the use of the mobile SSD batteries would not be increased significantly by this proposed use because the use is not significantly different from the alternative manual attachment of a power source to the ADS valves.

Thc consequences of an accident involving the use of the mobile SSD batteries at e not increased because the only significant consequences would be a delay in achieving cold shutdown and that would have no different consequences than would a delay due to an accident related to the currently used manual power source.

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ATTACHMENT D 1 SVP 98-114 NO SIGNIFICANT HAZARDS CONSIDERATION EVALUATION FOR USE OF THE MOBILE SSD BATTERIES PAGE 2 of 3

2) The possibility of a new or different kind of accident from any accident previously evaluated is not created. j The proposed change for the Quad Cities Station does not create the possibility of a new l or different kind of accident from that previously evaluated. Because the mobile SSD batteries simply provide a different form of manually connecting a source of power to the ADS valves, the use of the mobile SSD batteries does not present new or different kinds of accidents related to such manual actions. Finally, because no new modes of operation are introduced by the proposed change, the change does not create the possibility of a new or different kind of accident that could be related to new modes of operation.

3) No significant reduction in the margin of safety is involved.

The analytic framework for determining the extent to which a proposed change affects the margin of safety has been discussed above and, so will not be repeated here. In this case, a review of the proposed changes shows that they will not have an adverse impact on the ability to achieve and maintsn safe shutdown. Several features associated with the use of the mobile SSD batteries show, as discussed above, that it provides an effective method for achieving and maintaining safe shutdown following a fire. In particular, use of the mobile SSD batteries reduces the overall complexity of the cold shutdown repairs required to supply power to the ADS valves and is familiar to plant personnel from their training c n its use for other purposes.

Design calculations regarding capabilities of the mobile SSD batteries show they will be capable in Mfilling their intended safety function for their design basis Appendix R scenario. Reliability of the mobile SSD batteries will be maintained by augmented quality standards. This will entail the conduct of appropriate maintenance and surveillance which is iesigned to ensure that the mobile batteries will function as intended. Reliability of this power source is further enhanced by the circumstance that there are two mcbile SSD batteries, thus permitting one to act as a backup to the other.

Under these circumstances, the margin of safety for achieving cold shutdown using the ADS valves is not reduced significantly, if at all, by the use of non-safety related mobile SSD batteries to power the ADS valves. Although safety-related station batteries had previously been used in this function, the method for attaching those batteries was more prone to human error than the method which has been developed for the mobile SSD batteries. Moreover, substantial steps have been taken to provide a high level of reliability for the mobile SSD batteries. Overall, therefore, the ability to achieve and maintain safe shutdown in the event of a fire has not been reduced by this changc in the source of power to the ADS valves.

ATTACIIMENT D SVP 98-114 o NO SIGNIFICANT HAZARDS CONSIDERATION EVALUATION FOR USE OF TIIE MOBILE SSD BATTERIES PAGE 3 of 3 The NRC has provided guidance for the application of the significant hazards considerations standards in Final Rule, " Final Procedures and Standards on No Significant Hazard Considerationa," SIFR7744. This document provides examples ofchanges which are srd are not consiwred likely to involve significant hazards considerations. This proposed change does not involve a significant relaxation of the criteria used to establish safety limits, a significant relaxation of the bases for the limiting safety system settings, or a significant relaxation of the bases for the limiting conditions for operations. Therefore, based on the guidance provided in the Federal Register and the criteria established in 10CFR50.92(c), the proposed change does not involve a significant hazards consideration.

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A'ITACHMENT E SVP 98-114 t o ENVIRONMENTAL ASSESSMENT FOR PROPOSED CHANGE TO FACILITY l PAGE l of t Environmental Assessment Comed has evaluated the proposed amendment against the criteria for identification oflicensing and regulatory actions requiring environmental assessment in accordance with 10CFR51,21. It

, has been determined that the proposed changes meet the criteria for categorical exclusion as l provided under 10CFR51.22(c)(9). This conclusion has been reached because the changes

, requested do not pose significant hazards consideration and do not involve a significant increase l

in the amounts, and no significant changes in the types, of any effluents that may be released i offsite. Additionally, this request does not involve a significant increase in individual or l

cumulative occupational radiation exposure.

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