NLS2004111, Response to Request for Additional Information Regarding One Time Extension of Diesel Generator Allowed Outage Time

Response to Request for Additional Information Regarding One Time Extension of Diesel Generator Allowed Outage Time

ML042780486
Person / Time
Site:	Cooper
Issue date:	09/28/2004
From:	Minahan S Nebraska Public Power District (NPPD)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NLS2004111
Download: ML042780486 (18)

Text

Nebraska Public Power District Always there uhen you need us NlS20041 II September 28, 2004 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001

Subject:

Response to Request for Additional Infonmation Regarding One Time Extension of Diesel Generator Allowed Outage Time Cooper Nuclear Station, NRC Docket No. 50-298, Dl'R-46

References:

I. Letter to R. Edington (Nebraska Public Power District) from U.S. Nuclear Regulatory Commission (lated August 16, 2004, "Request for Additional hilbonnation Regarding One Time Extension of Diesel Generator Allowed Outage Time (TAC No. lMC3770)

2. Letter to R. Edin-lon (Nebraska public Power District) fromt U.S. Nuclear Regulatory Commission datedI August 27. 2004, "Request for Additional Inflonllation Regarding One Time Extension of [)iesel Generator Allowed Outage Time (TAC No. N\MC3770)

3. ILetter to U.S. Nuclear Regulatory Commission from R. Edington (Nebraska Public Power District) dated July 15, 2004, "License Amendment Request to Extend Diesel Generator Allowed Outage Time and Utilize Temporary Fuel Oil Storage Tanks on a One-Time Basis" (NLS2004076)

The purpose of this letter is for Nebraska Public Power District (NPPD) to respond to the Requests for Additional Information (RAIs) provided in References I and 2 by thie Nuclear Regulatory Commission (NRC) regarding the previously submitted License Amendment Request of Reference 3.

Attachment I provides NPP'D's response to the RAI provided by Reference I. Attachment 2 provides NPPD's response to the RAI provided by Reference 2. Note that Reference 2 did not contain a Question 5.

Should you have any questions concerning this matter, please contact Mr. Paul Flteming at (402)

S25-2774.

COOPER NUCLEAR STATION P.O. Box 98 / Brownville, NE 68321-0098 Telephone: (402) 825-3811 / Fax: (402) 825-5211 www.nppd com

NLS20041 11 Page 2 of 2 1 declare under penalty of perjury that the foregoing is true and correct.

Executed on __/ ___ __

(Date)

Sincerely, Stei rt B. Minaan General Manager of Plant Operations

/rar cc: Regional Administrator w/ attachments USNRC - Region IV Senior Project Manager w/ attachments USNRC - NRR Project Directorate IV-I Senior Resident Inspector w/ attachments USNRC Nebraska Health and Human Services w/ attachments Department of Regulation and Licensure NPG Distribution w/o attachments CNS Records w/ attachments

Attachment I NLS20041 11 Page I of 4 Response to "Request for Additional Information Regarding One Time Extension of Diesel Generator Allowed Outage Time (TAC No. MC3770)"

Dated August 16, 2004

Attachment I NLS20041 11 Page 2 of 4 NRC Request:

(1) In Section 4.3 of the amendment request the licensee states that the tempor-alay equipment requiredto performin dieselfitel movement ir'ill be locatedon an area of engineeredfill.

which is resistant to damage caused by seismic events. The licensee is requestedto (a) provide the basisfor this statement, including (b) a discussion ofthe level of earthquake ground motion and (c) the load transfer bet weeni the tanik and the engineecredfill. The licensee is also requested to discuss (d) the basisfor the statement that the temporamy eqiuipmenit -will remaiuifunctionalduring seismic events at this location, iucluding (e) a descriptionof the evaluation of the ability oftemporarypipingand 6D above-groundtank anchoragesto wi'ithstandseismic loadings.

NPPD Response:

(I a) Basis for Resistance to Seismic Damage The area in which the temporary storage tank(s) and pumping equipment are to be located is at the plant site grade surface (approximately elevation 903'-0') in the South East comer of the site Protected Area. The general area is best described as the area South of the existing Diesel Fuel Storage Tanks, East of the Condensate Storage Tank, and at the grade surface above the plant discharge tunnel (Seal Well Structure), which are shown on Bums and Roe drawing 4003 Updated Safety Analysis Report (USAR) reference drawing). This is an area in which the soil profile consists of highly compacted backfill down to the elevation of the bedrock at the site (approximate elevation 820'). This backfill, previously referred to as "engineered fill," is described as Type I Fill, or Structural Fill, as this level of compaction was utilized to provide the structural fill upon which the Class I and Class 11 Principal Structures were founded. This backfill was extended to grade around the Principal Structures, and is the same fill in which the Class I Diesel Fuel Storage Tanks and Class I Transfer Piping are imbedded. This fill is considered to be equivalent to the bedrock of the plant site, both in terms of structural stability, as well as in terms of the seismic input motion that structures found in, or upon, are subjected to during plant seismic events. Since the seismic ground motion is not amplified through this structural fill, the expected seismic input to the temporary equipment is expected to be low, such that the subject commercial components are not expected to be significantly damaged by the postulated seismic events.

(Ib) Level of Earthquake Ground Motion The structural fill does not amplify the design basis ground input motion of the postulated earthquakes, which is 0.1 Og for the Operating Basis Earthquake (OBE), and 0.20g for the

Attachment I NLS20041 11 Page 3 of 4 Safe Shutdown Earthquake (SSE). Thus, the maximum expected seismic input to the temporary equipment is 0.1 Og for the OBE condition, and 0.20g for the SSE condition.

(I c) Load Transfer to Temporary Equipment The load transfer between the temporary tank is dependent on the type of tank in question. The credited 21,000 gallons of off-loaded fuel is planned to be stored in a tank that rests directly on the grade surface. The load transfer is via friction between the tank bottom and the grade surface.

(Id) Temporary Equipment Function During Seismic Events The temporary installation is not intended to be a Class I Safety-Related installation, and is not intended to be capable of functioning durina a seismic event. The "temporary equipment" is located such that the temporarily stored volume of fuel will remain available after a seismic event, as the tank is not expected to suffer catastrophic damage due to an earthquake because the expected seismic input is judged insufficient to result in a rupture of the tank. The pumping equipment will not be connected to Safety-Related power supplies, nor will the transfer hoses be connected to the "in-service" underground storage tank. If necessary, transfer hoses can be connected between the temporary storage tank and the "in-service" underground storage tank, to replenish the "in-service" supply to an operating Diesel Generator (DG) Unit. The volume of fuel in the temporary tank represents a portion of the total stored volume of fuel required to support the seven day mission time of the in-service DG Unit under Design Basis Accident conditions. This portion of fuel is not required to be available to the operating DG unit for at least 4 days, since the "in-service" underground tank will be filled to maximum capacity.

(I e) Evaluation of Temporary Piping There are no plans to connect the "temporary equipment" to the "in-service" underground storage tank via piping. If necessary, transfer hoses can be connected between the temporary storage tank and the "in-service' underground storage tank. The hoses are flexible, and do not require evaluation for seismic loading conditions.

(If) Evaluation of Temporary Tank Anchorage The temporary storage tank is not planned to be anchored to the ground in any manner.

The input seismic accelerations are judged to be insufficient to cause significant lateral displacement of the tank. No horizontal accelerations sufficient to cause overturning of the tank is expected to occur. There will be no hard piping connections that could be

Attachment I NLS20041 11 Page 4 of 4 damaged by differential movements caused by the earthquakes. As such, no anchorage of the temporary tank is considered necessary.

NRC Request:

(2) The licensee is requested to provide bearingpressure and soil settlement data that might have been taken at the engineeredfill location to assur-ethat differential settlement is not ocCdTlring at this time and the soil bearingpressunre is adequate to suppor the temporaly equipment in a stable manner-.

NPPD Response:

(2) The "engineered fill" is the "Type I structural fill" which provides the structural support for the Class I and Class 11 Principal Structures at Cooper Nuclear Station. This fill is not expected to experience differential settlement or liquefaction during either of the Design Basis Seismic Events. This highly compacted soil has a minimum Design Basis allowable bearing pressure of 12,000 psf for the OBE condition, and 10,000 psf for the SSE condition. Based on the original Design Criteria for the structural fill, the bearing pressure is considered more than adequate to support the temporary equipment in a stable manner.

NLS20041 11 Page I of 10 Response to "Request for Additional Information Regarding One Time Extension of Diesel Generator Allowed Outage Time (TAC No. MC3770)"

Dated August 27, 2004 NLS20041 11 Page 2 of 10 NRC Request:

1. Discuss andprovide information onl the reliability of the transferscheme firomn nornial station service transformer (NSST) to startup station service transformer (SSST) relating to the proposedchange. The discussion shotld include transfer time, cause, date and time of each trantsfer-andani'faihmires ini thesclheme to tramisfer-stccessfuilli. In case of failure of tie transferfrom the NSST to SSST, how long does it take to transfer the 4.16 kl'safety buses to emergency station service transformer(ESST). Discuss whether the transferfi-omn SSST to El;SST is automatic or manual.

NPPD Response:

I. Cooper Nuclear Station (CNS) Technical Specifications require two qualified circuits between the offsite transmission network and the onsite Class I E AC Electrical Power Distribution System. The two qualified offsite power sources are a startup station service transformer (SSST) which connects to the 161 kV switchyard and a separate emergency station service transformer (ESST) energized by a 69 kV line. The 161 kV switchyard is connected to one 161 kV line which terminates in a switchyard near Auburn, Nebraska, and the 345/161 kV auto-transformer which connects to the 345 kV switchyard. The 345 kV swvitchyard has five lines which terminate in switchyards near Booneville, Iowa; Hallam, Nebraska; St. Joseph, Missouri; Fairport, Missouri; and Nebraska City, Nebraska. The ESST is fed by a 69 kV line which is part of a subtransmission grid of the Omaha Public Power District. The design of the offsite AC electrical power system provides independence and redundancy to ensure a reliable source of power to the Engineered Safety Feature systems.

The automatic transfer to the SSST is a "fast transfer" scheme which prevents a significant voltage drop and is measured in cycles. The automatic transfer to the ESST is a dead bus transfer which involves a delay of approximately I second. The critical bus required loads are sequentially loaded to the buses after the transfer to the ESST.

USAR Section VII-1.0 provides the following description:

If the normal station service transformer is lost, the startup station service transformer, which is normally energized, will automatically energize 4160 volt buses IA and I B as well as their connected loads, including the critical buses. If the startup station service transformer (SSST) fails to energize the critical buses, the emergency station service transformer, which is normally energized, will automatically energize both critical buses. If the emergency station service transformer (ESST) were also to fail, the DGs would automatically energize their respective buses.

NLS2004111 Page 3 of 10 Within the last five years, CNS has conducted three Refueling and a number of Forced Outages which required a planned transfer from the NSST to the SSST during shutdown and from the SSST to the Normal Station Service Transformner (NSST) during startup. A Forced Outage in the fall of 2000 involved a scram and successful automatic transfer from the NSST to the SSST.

A review of CNS total operating history indicates three events when a successful transfer to the SSST did not occur. The last event occurred in October of 1990. All three events started both diesel and transferred loads to the ESST. The station successfully shutdown on the ESST without loading either diesel.

The first event occurred in the 1970s, when only four 345 kV lines connected the CNS generator output and switchyard to the grid. A loss of three of the lines (from grid events) tripped the CNS generator due to the one remaining line's protective relaying tripping on the sudden increase of the entire generator output. The loss of all four lines de-energized the auto-transforner 161 kV supply to the SSST. The 69 kV supply to the ESST was unaffected and energized the critical buses. Both DGs started but did not load during this event.

The second event occurred in January 1984 with CNS operating without a NSST due to failure of the transformer in December 1983. The station was powered entirely from the SSST. Heavy wind conditions blew a piece of reactor building siding off and caused a phase-to-phase fault on the 161 kV lines supplying the SSST. The 161 kV breakers opened to isolate the fault. The generator tripped and plant scrammed on loss of AC power. The ESST was unaffected and energized the critical buses to shutdown the station. Both DGs started but did not load during this event.

The last event was in the October of 1990. An elevator power cable from a temporary exterior elevator to the Reactor Building roof was blown near a 345 kV generator output line causing a phase to ground fault. This caused a generator trip. A piece of the cable was blown into the 161 kV line causing a phase-to-phase fault on the 161 kV line preventing a transfer to the SSST. The ESST was unaffected and energized the critical buses to shutdown the station. Both DGs started but did not load during this event.

NRC Request:

2. II is NRC staffs understandingthat the purpose of the requestedamendment is to allowt an increasedoutage time duringplantpouwer operationfor corrective maintenance to the fuel oil storagetanks and transfersystem. Provide information on tests to be pemformned after corrective maintenanceto thefuel oil storage tanks and transfersystem is complete in orderto declare the diesel generator(DG) operable. Providejustificationfor peiformlning those tests atpower; NLS20041 11 Page 4 of 10 NPPD Response:

2. Post Maintenance Testing, in accordance with station surveillance procedures for the following activities, will be conducted at the conclusion of each divisional work window.

"DIESEL FUEL OIL AVAILABILITY" which satisfies Technical Specification (TS) Surveillance Requirements (SR) 3.8.3.1 to ensure an adequate inventory of fuel oil is available, and SR 3.8.3.5 which checks for and removes accumulated water from the storage tanks.

"DIESEL FUEL OIL STORAGE TANK, BUNKER A & B QUALITY TEST" satisfies TS SR 3.8.3.3, in part, to ensure fuel oil properties are within limits of the Diesel Fuel Oil Testing Program.

"DIESEL GENERATOR 31 DAY OPERABILITY TEST (1ST)" which satisfies SR 3.8.1.2 to verify the DG starts from standby conditions and achieves required steady state voltage and frequency, SR 3.8.1.3 to verify the DG is synchronized, loaded, and operates for greater than 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> while loaded, SR 3.8.1.4 to verify fuel level in the day tank, SR 3.8.1.5 to remove accumulated water from the day tank, SR 3.8.1.7 to verify the DG starts and loads from standby conditions and achieves required voltage and frequency within 14 seconds and maintains the required voltage and frequency after steady state conditions are achieved, SR 3.8.3.2 which verifies lube oil inventory, and SR 3.8.3.4 which verifies the starting air system pressure.

"DIESEL GENERATOR FUEL OIL TRANSFER PUMP ]ST FLOW TEST" which satisfies conditions of TS Section 5.5.6, Inservice Testing Program.

Additionally, the diesel fuel oil duplex strainer will be inspected and cleaned.

The above post maintenance surveillance and testing activities are normal periodic activities that are routinely performed with the plant on-line.

NRC Request:

3. ldiat tape of comnininicationhas been establishedbetween the control room operatorat Cooper Nuclear Station and tihe System Load Dispatcheri? Is the System Load Dispatchernotified in advance that the DG is going to be outfor extendedperiodof time?

NLS2004111 Page 5 of 10 NPPD Response:

3. NPPDs "Interface Operating Agreement" between the Energy Delivery Business Unit (System Load Dispatcher) and the Nuclear Power Group Business Unit (CNS), and its implementing procedures, establish the required communications protocol.

The Energy Management System at the Doniphan Control Center (DCC) contains a State Estimator that models current grid conditions. The Security Analysis function models the impact of a defined set of contingencies on the model. The Security Analysis predicts what voltage will be provided by the ESST or SSST under the conditions of the contingency. Each contingency specifies a CNS generator trip and accident loading of the associated transformer(s). If the predicted voltage is below that which is required then it is prudent to declare the effected transformer and line inoperable. Required voltage is greater than 3950 volts on the safety related 4160 volt buses, which is above the second level undervoltage relay reset value. This provides a high level of assurance that multiple load shedding and sequencing of safety related loads Would not occur. The use of the State Estimator and Security Analysis supercedes the previous worst-case analysis voltage limits. However, these voltage limits are still used as a backup method in the event the Security Analysis is out of service.

The Security Analysis solves every 10 minutes and following system configuration changes. The following three CNS specific 4160 volt violation scenarios, directly related to the operability of our offsite sources, are built into the Security Analysis.

I. Cooper Unit Off-Line, SSST Voltage. Post unit trip undervoltage 95% of 416OV, or overvoltage 105% of 4160V, with post trip station service load on SSST.

2. Cooper Unit Off-Line, ESST Voltage. Post unit trip undervoltage 95% of 416OV, or overvoltage 105% of 416OV, with post trip station service load on ESST.

3. Cooper Generator Off and T-2 Open, ESST Voltage. Post unit trip undervoltage 95% of 416OV, or overvoltage 105% of 416OV, with post trip station service load on ESST.

Contingencies that have predicted violations are reported to the DCC System Operator via the violation summary display. When a Security Analysis Violation occurs the Energy Delivery Operators are required to notify the CNS Control Room, and entry into procedure 5.3GRID, degraded Grid Voltage, is required.

Communication between the CNS Control Room and the System Load Dispatcher can be accomplished via normal land telephone lines, dedicated trunk lines and a microwave NLS20041 11 Page 6 of 10 telephone system. Additional communication methods available are through National Weather Service radio communication or relaying with law enforcement agencies.

Technical Specifications require verification of proper circuit continuity for the off-site AC electrical power supply to the on-site distribution network and availability of off-site AC electrical power when Limiting Conditions for Operation associated with an inoperable diesel generator are entered. Performance of this verification requires communication with the System Load Dispatcher.

The Special Procedure governing the fuel tank maintenance activity will establish additional controls for the required communication during the tank maintenance activity.

No other scheduled activities (i.e., corrective or elective maintenance) challenging offsite power sources, including the secondary & emergency transformers will be planned for the duration of the storage tank coating activities. Existing administrative controls for coordination of work in switch yards and transformer yards will be utilized to minimize the risk of power loss to equipment important to plant safety. It will be a specific requirement of the Special Procedure to ensure that this information is communicated to the System Load Dispatcher.

NRC Request:

4. Other licensees who requestedjforDGallowed outage time (AOT) extensionprovided the following Regulatort Comnitments in their requests.

A. Whiether conditions ivill be evaluatedpriorto entering the extendedDGAOTfor voluntaiy)plannedmaintenance. An extended DGAOT will not be enteredfor voluntai3'plannedmaintenancepurposes ifofficial itveatherforecasts are predictingsevere conditions (tornado or thunderstorm walrnings).

B. The condition of thi offsite power supply and switch yard ivill be evaluatedprior to entering the extended A OT.

C No discretionayswitch yard maintenance will be allowted. In addition, no discretionaiymaintenance will be allotwed on the main, auxiliai) or startup transformnzer-s associatedwith the unit.

D. No maintenance or testing that affects the reliability of the train associatedwith the OPERABLE DG whill be scheduled duriuig the extended AOT If any testing and maiiitenanceactivities niust bepemfoniied whlile the extendedAOT is in effect, an evaluation itill be pejfor-med in accordancewith Section 50.65(a)(4) of Title 10 of the Code of FederalRegutlations (JO CFR).

NLS2004I 11 Page 7 of 10 E. The steam driven emergencyfeed waterpump wtill not be takenz out of servicefor planned maintenance activities and wtill be treatedas protected equipment.

F. The system dispatcherwt-ill be contacted once per days and informed of tie DG status along lwith the powter needs ofthefacilitj.

G. The on-shift Operations crews w'ill discuss and review appropriatenormal and emergency operatingprocedures upon or priorto assulming the Watch for thefirst time after having scheduled days off while the AOT is in effect.

I. The Operationscrews itill be briefed concerning the unit activities, including compensatory measures establishedfollowtinginstruction of the Shift Manager pon tihe loss of a powt er ev ent. Thlis brie fing wt ill be peiforniedupon orprior to assuming the W[atch for thefirst time after having scheduled days offlh ihe the AOTis in effect.

Pleaseprovide the prov isions, limitations and compensatory actions wvith respect to tile above that NPPD will be committing to implement to assure adequate defense in dept/,

during the extended DG A OT.

NPPD Response:

4. During the extended Allowed Outage Time (AOT) the inoperable DG will be maintained available to start and load and will be capable of a minimum five hours of full load operation using fuel in its' associated day tank. The fuel tank maintenance activity will be conducted during a work week that normally supports DG maintenance. However, no planned activities which would impact the ability of the DG to start and load will be performed on the inoperable DG.

A. Weather Conditions The Special Procedure for the fuel tank maintenance activity will contain the requirement to evaluate weather conditions prior to entering the activity.

B. Offsite Power Supply Evaluation Technical Specifications require verification of proper circuit continuity for the off-site AC electrical power supply to the on-site distribution network and availability of off-site AC electrical power when Limiting Conditions for Operation associated with an inoperable diesel generator are entered. This surveillance will be performed in advance of moving the DG fuel supply to the NLS20041 11 Page 8 of 10 temporary storage tanks. Performance of this verification requires communication with the System Load Dispatcher.

In addition, the Special Procedure for the fuel tank maintenance activity vill provide control to ensure this evaluation is performed prior to moving the fuel supply to the temporary tanks. The DG associated with the drained fuel oil storage tank will remain available to start and load with fuel supplied from its day tank. Defense-in-depth strategies to supply fuel to the inoperable but available DG from permanent and temporary storage facilities have been developed.

C. Discretionary Switchyard Maintenance NPPD provided the following commitment in the initial License Amendment Request:

Plant activities with the potential to challenge diesel generator operability or availability, or availability of Emergency Core Cooling Systems, critical switchgear/electrical buses, offsite power sources or safety related cooling water systems will not be planned for the duration of the fuel tank maintenance activities.

Discretionary maintenance affecting the switchyard and transformers is included in the above commitment.

D. Maintenance Affecting Operable Diesel Generator NPPD provided the commitment noted in "C" (above) in the initial License Amendment Request. Maintenance or testing that affects the reliability of the train associated with the operable DG is included in that commitment. NPPD has additionally committed to maintain the inoperable DG available to start and load.

If any emergent plant activities that affects the reliability of the train associated with the OPERABLE DG were to arise, CNS is obligated by 10 CFR 50.65 to perform the specified evaluation.

E. Steam Driven Pumps NPPD provided the commitment noted in "C" (above) in the initial License Amendment Request. With regard to Steam Driven Pumps, NPPD is a General Electric Boiling Water Reactor 4 and does not have emergency feedwater pumps.

The High Pressure Coolant Injection (HPCI) system is a steam driven system with the capability to restore reactor vessel inventory. HPCI is included in the NLS2004l 11 Page 9 of 10 Emergency Core Cooling Systems and will remain available during the fuel tank maintenance activities.

F. Daily Diesel Generator Status The special procedure for the fuel tank maintenance activity will provide control for including communication of the DG status and CNS power needs to the system dispatcher on a daily basis for the duration of the activity. In addition, a grid security computer program provides near real time analysis of the condition of the grid.

G. Review of Operating Procedures The Special Procedure for the fuel tank maintenance activity will require the Operations crew to review appropriate normal and emergency procedures prior to assuming the watch while the extended AOT is in effect.

H. Briefing of Unit Activities The Special Procedure for the fuel tank maintenance activity will require the briefing of the operations crew concerning unit activities and measures to perform the defense-in-depth activities to ensure fuel oil is supplied to the DGs to support 7 days of full load operation, prior to assuming the watch while the extended AOT is in effect.

NRC Request:

6.[sic] Discuss regzdatoi) commitments to implement otheir restrictionsand compeuisatoi) measures during the extended A OT that would ensure the availabilityof the remaining sources ofpower to minimize the occurrence of a station black out and ensure compliance wit/l the requirements of 10 CFR Part 50, Appendix A, GeneralDesign Criterion(GDC) 17, "Electricpower systems" and GDC 18, "Inspection and testing of electricpower systenis.'

NPPD Response:

6. NPPD has implemented the recommendations of the Institute of Nuclear Power Operations, Significant Operating Experience Report 99-1, "Loss of Grid." The implemented actions include agreements, procedures, calculations and training to ensure a reliable off-site power system. The maintenance activity to clean and coat the storage tanks does not increase the probability of a Station Black Out (SBO) due to maintaining the inoperable DG available to start and load.

NLS20041 11 Page 10 of 10 During the tank maintenance activities, both DGs will remain available to start and load in the event a SBO would occur. CNS has developed defense-in-depth strategies to ensure the 49,500 gallon fuel oil inventory required to support seven days of fully loaded operation can be supplied to either DG as necessary. A minimum 28,500 gallons of fuel oil (greater than 4 days operation) will be stored in fully qualified permanent storage tanks with 21,000 gallons of fuel stored in a temporary above ground tank located on engineered fill. In the unlikely event that fuel in the temporary tank were to become unavailable to support operation of the DG beyond 4 days, replenishment of fuel from offsite can be accomplished in approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. NPPD has verified the supplier's capability to deliver replenishment fuel independent of AC power sources.

NRC Request:

7.[sic] Discuss whether the temporai3'tubingfrom the temnporary tank will remain connected to the daye tank supply line during the DG AOT. Additionally; discuss how the temporary tubing and its routing be protectedfrom site traffic and ongoing maintenance and construction activities.

NPPD Response:

7. Temporary equipment will not be connected to diesel oil storage and transfer system to support diesel generator operation during the tank coating maintenance activity. The equipment to transfer fuel oil from the temporary storage tanks to support diesel generator operation, in accordance with contingency and defense-in-depth plans, will be pre-staged to ensure it is available in the event of a diesel generator start. Additional staffing will be continuously available to implement the defense-in-depth plans. The inoperable DG will remain available to start and load throughout the maintenance activity.

I ATTACHMENT 3 LIST OF REGULATORY COMMITMENTSl Correspondence Number: NLS2004111 The following table identifies those actions committed to by Nebraska Public Power District (NPPD) in this document. Any other actions discussed in the submittal represent intended or planned actions by NPPD. They are described for information only and are not regulatory commitments. Please notify the Licensing & Regulatory Affairs Manager at Cooper Nuclear Station of any questions regarding this document or any associated regulatory commitments.

COMMITTED DATE COMMITMENT OR OUTAGE Existing administrative controls for coordination of work in switchyards and transformer yards will be utilized to minimize the risk of power loss to equipment important to plant safety. It will be a specific requirement October 20, 2004 of the Special Procedure to ensure that this information is communicated to the System Load Dispatcher.

The Special Procedure for the fuel tank maintenance activity will contain the requirement to evaluate weather conditions prior to entering October 20, 2004 the activity.

The Special Procedure for the fuel tank maintenance activity will provide control to ensure this evaluation (verification of proper circuit continuity for the off-site AC electrical power supply to the on-site October 20, 2004 distribution network and availability of off-site AC electrical power when Limiting Conditions for Operation associated with an inoperable diesel generator are entered) is performed prior to moving the fuel supply to the temporary tanks.

The special procedure for the fuel tank maintenance activity will provide control for including communication of the DG status and CNS powver needs to the system dispatcher on a daily basis for the duration of October 20, 2004 the activity.

The Special Procedure for the fuel tank maintenance activity will require the Operations crew to review appropriate normal and emergency procedures prior to assuming the watch while the extended October 20, 2004 AOT is in effect.

The Special Procedure for the fuel tank maintenance activity will require the briefing of the operations crew concerning unit activities and measures to perform the defense-in-depth activities to ensure fuel oil is October 20, 2004 supplied to the DGs to support 7 days of full load operation, prior to assuming the watch while the extended AOT is in effect.

PROCEDURE 0.42 l REVISION 15 PAGE 20 OF 27

ATTACHMENT 3 LIST OF REGULATORY COMMITMIENTSl Correspondence Number: NLS2004111 The following table identifies those actions committed to by Nebraska Public Power District (NPPD) in this document. Any other actions discussed in the submittal represent intended or planned actions by NPPD. They are described for information only and are not regulatory commitments. Please notify the Licensing & Regulatory Affairs Manager at Cooper Nuclear Station of any questions regarding this document or any associated regulatory commitments.

COMMITTED DATE COMMITMENT 4-OR OUTAGE Requirements for Post Maintenance Testing, in accordance with station surveillance procedures for the following activities (DIESEL FUEL OIL AVAILABILITY, DIESEL FUEL OIL STORAGE TANK, BUNKER A

& B QUALITY TEST, DIESEL GENERATOR 31 DAY October 20, 2004 OPERABILITY TEST (1ST) and DIESEL GENERATOR FUEL OIL TRANSFER PUMP IST FLOW TEST) and duplex strainer inspection and cleaning to be conducted at the conclusion of each divisional work window will be included in the Special Procedure.

I PROCEDURE 0.42 l REVISION 15 l PAGE 21 OF 27