ML18037A874
| ML18037A874 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 05/11/1994 |
| From: | Salas P TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML18037A875 | List: |
| References | |
| NUDOCS 9405170104 | |
| Download: ML18037A874 (56) | |
Text
ACCELERATED DI. TRIBUTION DEMONS TION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RXDS)
ACCESSION NBR:9405170104 DOC.DATE: 94/05/ll NOTARIZED: YES DOCKET FACIL:50-260 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260 AUTH. NAME AUTHOR AFFILIATION SALAS,P. Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk) R
SUBJECT:
Application for amend to license DPR-52,consisting of TS Change TS-347T to temporarily extend AOT of TS 3.9.B.S while TVA replaces batteries 6 associated hardware that suppy 250 volt dc control power to Units 1 6 2 shutdown boards. D DISTRIBUTION CODE: A001D COPXES RECEIVED:LTR / ENCL J SIZE: ~
TITLE: OR Submittal: General Distribution NOTES RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL D PD2-4 1 1 PD2-4-PD 1 1 TRIMBLE,D 2 2 D INTERNAL: ACRS 6 6 NRR/DE/EELB 1 1 NRR/DORS/OTSB 1 1 NRR/DRCH/HICB 1 1 NRR/DRPW 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 NUDOCS-ABSTRACT 1 1 OC 1 0 OGC/HDS3 1 0 EG FI 01 1 1 EXTERNAL: NRC PDR 1 1 NSIC 1 1 D
D D
NOTE TO ALL "RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENI'ONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISIS FOR DOCUMENTS YOU DON'T NEED!
TOTAL NUMBER OF COPIES REQUIRED: LTTR 22 ENCL 20
Tennessee Valley Authority, Post Olfice Box 2000, Decatur, Alabama 35609 HlY 115M TVA-BFN-TS-347T 10 CFR 50. 4 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 Gentlemen:
In the Matter Of Docket No. 50-260 Tennessee Valley Authority BROWNS FERRY NUCLEAR PLANT (BFN) UNIT 2 TECHNICAL SPECIFZCATZON (TS) No 347T - TEMPORARY EXTENSION TO 250 VOLT DC CONTROL POWER SUPPLY SYSTEM ALLOWED OUTAGE TIME (AOT)
REQUEST FOR NRC REVIEW AND APPROVAL OF COST BENEFICIAL LICENSING ACTION (CBLA). .07 In accordance with the provisions of 10 CFR 50.4 and 50.90, TVA requests an amendment to operating license number DPR 52 to temporarily change the Unit 2 TSs. The primary purpose of the change is to extend the AOT of TS 3.9.B.8 while TVA replaces the batteries and associated, hardware that supply 250-volt DC control power to the Unit 1 and 2 shutdown boards. This request is being submitted as a CBLA.
Modifications to replace the batteries and associated hardware .need to be performed on each of the four (4) Unit 1/2 power supplies in the 250 Volt DC Control Power Supply System. These power supplies provide control power to the Unit 1/2 480-volt and 4160-volt shutdown boards. The modifications are needed because additional capacity will be added to support multi-unit operation, and the batteries are approaching the end of their service life. Approximately 45 days are needed to perform the modifications and conduct necessary testing for each power supply.
The operability requirements for the affected shutdown board control power supplies are prescribed in TS Limiting Condition for Operation 3.9, "Auxiliary Electrical System."
TS 3.9.B.8 establishes an AOT of five (5) days if one of the batteries and/or associated battery board that supplies r~
,.'9405170i04 940511 j qol PDR ADOCK 05000260 p PDR j )
U. S. Nuclear Regulatory Commission Page 2 N5 iI 1994 shutdown board control power is inoperable. In order to replace the control power batteries and associated hardware, TVA requests that the AOT be extended to 45 days.
TVA requests that the change to the TS be granted for a period of one year to allow sufficient time to perform the power supply modifications. The modifications will be performed in series such that only one power supply is being modified at a time. The one year includes a 45-day modification/testing period for each power supply, a two week period in between each power supply outage to conduct related surveillance testing and maintenance, and a four month period for contingencies.
TVA will implement compensatory measures while performing the modifications during operation. These compensatory measures include developing a special procedure to address actions for dealing with transients or accidents, restricting the testing and maintenance that can be performed while modifications are in progress, and providing alternative means of supplying control power. Additionally, TVA has performed a Probabilistic Safety Assessment (PSA) to assess the increase in risk associated with extending the AOT. TVA's PSA shows that the increase in risk is negligible. to this letter provides the description and evaluation of the proposed change. Enclosure 2 contains a copy of the appropriate Unit 2 TS pages marked-up to show the proposed change. Enclosure 3 provides the support documentation discussed in the description and evaluation of the proposed change. Enclosure 4 forwards the revised Unit 2 TS pages that incorporate the proposed change. Enclosure 5 provides TVA's PSA.
Additionally, TVA requests NRC review and approval of this change as a CBLA. TVA has determined that the change represents a CBLA since the alternatives to performing the work at power involve high cost and low safety benefit. TVA has evaluated alternatives such as extending the next Unit 2 refueling outage and installation of a qualified, temporary battery. Since appropriate compensatory measures can be implemented and the PSA indicates low risk, TVA considers that the costs of the alternatives're not justified. TVA estimates that approval of this change would save approximately $ 1,000,000. Enclosure 6'rovides the basis for the request and justification for higher priority NRC review.
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U. S. Nuclear Regulatory Commission Page 3 NK( 1 i 1994 TVA has determined that there are no significant hazards considerations associated with the proposed change and that the change is exempt from environmental review pursuant to 10 CFR 51.22(c)(9). The Browns Ferry Plant Operations Review Committee and Nuclear Safety Review Board have reviewed this proposed change and determined that operation of BFN Unit 2 in accordance with the proposed change will not endanger the health and safety of the public. Additionally, in accordance with 10 CFR 50.91(b)(l), TVA is sending' copy of this letter and enclosures to the Alabama State Department of Public Health.
TVA requests that the change be issued by December 1, 1994, and be effective for a period of one year from January 1, 1995, to December 31, 1995. The commitments associated with this change request are provided in . If you have any questions about this change, please telephone me at, (205)729-2636.
Sincerely, as Manager of Site Licensing Enclosures cc: See page 4 Subscribed and sworn to before on this ~~ day of 1
me 1994.
Notary Public My Commission Expires
U.S. Nuclear Regulatory Commission NAY ii J994 Enclosures cc (Enclosures):
American Nuclear Insurers Town Center, Suite 300S 29 South Main Street West Hartford, Connecticut 06107-2445 Mr. W. D. Amdt General Electric Company 735 Broad Street Suite 804, James Building Chattanooga, Tennessee 37402 Mr. Johnny Black, Chairman Limestone County Commission 310 Washington Street Athens, Alabama 35611 Mr. Mark S. Lesser, Section Chief U.S. Nuclear Regulatory Commission Region 101 II Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 NRC Resident Inspector Browns Ferry Nuclear Plant Route 12, Box 637 A'thens, Alabama 35611 Mr. David C. Trimble, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Mr. Joseph F. Williams, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Dr. Donald E. Williamson State Health Officer State Department of Public Health State Office Building Montgomery, Alabama 36194
U.S. Nuclear Regulatory Commission NAY 1.1 1994 Enclosures cc (Enclosures):
Mr. R. P. Zimmerman U.S. Nuclear Regulatory Commission 11555 Rockville Pike Rockville, Maryland 20852
ENCLOSURE 1 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)
UNIT 2 PROPOSED TEMPORARY TECHNICAL SPECIFICATION (TS) CHANGE TS-347T DESCRZPTZON AND EVALUATZON OF THE PROPOSED CHANGE INDEX I. DESCRIPTION OF THE PROPOSED CHANGE El-2 II. REASON FOR THE PROPOSED CHANGE El-8 III. SAFETY ANALYSIS El-14 IV. NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION El-23 V. ENVIRONMENTAL IMPACT CONSIDERATION El-25
I. DESCRIPTION OF THE PROPOSED CHANGE
~Summar TVA requests a temporary change to the Unit 2 TS in order to perform modifications to the Unit 1/2 portion of the 250-volt DC control power supply system. TVA requests that the change be granted for a period of one year.
The 250-volt DC control power supply system provides control power to the Unit 1/2 480-volt and. 4160-volt shutdown boards'. ,The primary purpose of the change is to extend the allowed outage time (AOT) specified in TS 3.9.B.8 for the control power supplies. Additionally, the change removes NRC notification requirements, permits restart following an unplanned shutdown if the power supplies are inoperable to perform planned modifications, and incorporates editorial changes. LCO 3.9.B.8 states:
From and after the date that one of the 250-V shutdown board batteries and/or its associated battery board is found to be INOPERABLE for any reason, continued REACTOR POWER OPERATION is permissible during the succeeding five days in accordance with 3.9.B.7.
The reference to LCO 3.9.B.7 requires that NRC be "notified within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of the situation, the precautions to be taken during this period, and the plans to return the failed component to an OPERABLE status."
The requested changes to LCO 3.9.B.8 involve the following principal elements:
Extend the AOT from five (5) days to forty-five (45) days.
Remove the NRC notification requirements if the batteries are inoperable to perform planned modifications.
Permit resumption of power operation if an unplanned shutdown occurs.
The word "INOPERABLE" is being decapitalized in order to be consistent with the TS Definitions.
The shutdown board control power supplies are referred to as the "250-volt DC control power supply systems" in the BFN Final Safety Analysis Report (FSAR), and the "250-V shutdown board batteries, and/or its associated battery board" in the TS. For consistency, the FSAR terminology will be used unless otherwise noted.
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Additionally, TVA requests that a note be added to TS 3.9.A.4 that permits resumption of power operation as specified in the revised TS 3.9.B.8. TS 3.9.A.4 prescribes the auxiliary electrical power system operability requirements for startup. This specification requires that the Unit 1/2 shutdown board control power supplies be operable prior to startup from cold or hot standby conditions.
Back round The objective of TS 3.9 is to assure an adequate source of electrical power to operate components needed to cool the plant during shutdown and to operate the engineered safeguards following an accident. Electrical power to many of these components is supplied through the 480-volt and/or 4160-volt shutdown boards.
There are eight 4160-volt shutdown boards at BFN Units 1, 2, and 3. These shutdown boards are designated A, B, C, D, 3EA, 3EB, 3EC, and 3ED. Shutdown boards A, B, C, and D are associated with Unit 1/2. Shutdown boards 3EA, 3EB, 3EC and 3ED are associated with Unit 3. The 4160-volt shutdown boards receive their power from offsite sources (161-kV transmission system or 500-kV transmission system) or the on-site emergency electrical supplies (eight 4160-volt diesel generators).
There are six 480-volt shutdown boards at BFN Units 1, 2, and 3. These shutdown boards are designated 1A, 2A, 3A, 1B, 2B, and 3B. Each unit has an "A" and a "B" 480-volt shutdown board (e.g., shutdown boards lA and 1B are associated with Unit 1). The "A" 480-volt shutdown "B" boards are associated with Division 1 equipment. The 480-volt shutdown boards are associated with Division 2 equipment.
The 480-volt shutdown boards receive their power from the 4160-volt shutdown boards.
Each shutdown board (480-volt and 4160-volt) requires control power that is supplied by the 250-volt DC Power Supply and Distribution System (FSAR section 8.6). The 250-volt DC Power Supply and Distribution System is made up of two subsystems: ~ ~
The 250-volt DC control power supply system, which consists of five power supplies (a 120-cell lead-acid battery and battery charger for each power supply, and one spare battery charger), together with the associated chargers, circuitry, switches, indicators, and alarms. Four of the power supplies are associated with Unit 1/2 shutdown boards. The fifth power supply is used to support a Unit 3 shutdown board. The power supplies are referred to as the "shutdown board batteries and/or its associated battery board" in TS 3.9.B.8.
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The subsystem supplies 250-volt DC control power to Unit 1/2 4160-volt shutdown boards A, B, C, D; Unit 3 4160-volt shutdown board 3EB; and Unit 1/2 480-volt shutdown boards lA, lB, 2A, and 2B. The system also supplies normal and alternate power to the nonsafety-related Anticipated Transient Without Scram (ATWS) protection system.
The 250-volt plant DC system, which consists of four 120-cell lead-acid batteries (one Class 1E battery and battery charger per unit, one non-Class lE station battery and battery charger, and one Class 1E spare battery charger), together with the associated chargers, circuitry, switches, indicators, and alarms.
Three of these power supplies are safety-related. The safety-related power supplies are referred to as the "unit batteries and/or its associated battery board" in TS 3.9.B.7.
The 250-volt plant DC system supplies operating and motive power to various plant components (e.g., valve motor operators, motor generator sets); control power for Unit 3 4160-volt shutdown boards 3EA, 3EC, and 3ED; and Unit. 3 480-volt shutdown boards 3A and 3B.
The shutdown board control power supply systems and their power alignment are shown in Figure 3-1. The divisional lineup of the safety related 250-volt plant DC systems are shown in Figure 3-2. Single line diagrams for the 250-volt DC shutdown board control power supplies are provided in Figure 3-3. These figures are provided in Enclosure 3.
250-Volt DC Control Power Su l S stem shutdown board control power All five of the 250-volt DCrelated.
supply systems are safety The shutdown board control power supply systems are normally energized by their dedicated battery charger. On loss of power to the charger, the battery supplies all required loads.
The batteries are needed for battery charger failures or loss of offsite power situations until their associated emergency diesel generator (EDG) can start, load, and the charger can pick up control power loads. The battery would not be needed if an EDG failed since equipment the EDG supplies would not be available. Additionally, each shutdown board has provisions for being energized from a 250-volt plant DC power supply via a manual transfer switch or a portable spare charger.
The batteries for each of the shutdown board control power supplies are of lead-calcium grid construction. They have a 1-minute rating of 148 amperes and an 8-hour discharge rating of 100 ampere hours, both ratings to a terminal the voltage of 210-volts at 77'ahrenheit (F). Although
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safety design basis requirement'for battery capacity is 30 minutes, the batteries have a greater capacity to supply all required loads allowing ampleoccurs.time for corrective action if a charger malfunction Each battery is equipped with a low-voltage alarm that actuates when battery voltage falls to 240 volts.
The shutdown board control power supply battery chargers are of the solid-state, rectifier type, capable of working independently. Each charger is capable of automatically regulating output voltage within +0.5 percent. of its rated value under the following conditions:
The load is between 0 percent and 100 percent with the AC power feeding the charger deviating from the rated voltage by 10 percent.
The battery is disconnected.
Each battery charger has the capacity to furnish floating, equalizing, and fast charge in accordance with the battery manufacturer's recommendations. The battery chargers are powered off the 480-volt shutdown boards. Each battery charger provides the 250-volt DC supply during normal operations, keeps its associated battery fully charged at all times, and recharges the battery after a discharge.
250-Volt Plant DC S stem The 250-volt plant DC system consists of three safety-related and one nonsafety-related 250-volt plant DC power supplies. The nonsafety-related 250-volt plant DC power supply is outside the scope of this license amendment request and will not be discussed further. The following discussion of the 250-volt plant DC power supplies, applies to the safety related portion of the system only.
The 250-volt plant DC power supply batteries are of lead-calcium grid construction. These batteries have a one-minute rating of 2080 amperes. The chargers and associated equipment are similar to those described above; however, they are correspondingly bigger.
The 250-volt plant DC power supplies are designed to supply selected safety-related plant loads. Any two out of the three safety-related plant DC power supplies are designed to carry the loads required for all three units. Typical major loads for the plant DC power supplies include:
Autodepressurization Relief Valves Main Steam Pressure Relief Valves Main Steam Isolation Valves Recirculation Motor-Generator Set Emergency Oil Pumps Backup Scram Valves Residual Heat Removal Shutdown (RHR) Isolation Valves
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Division I and II Engineered Safeguards Logic High Pressure Coolant Injection System (HPCI)
Reactor Core Isolation Cooling System (RCIC)
Primary Containment Isolation System outboard isolation valves Unit 3 480-volt and 4160-volt shutdown board control power The 250-volt DC Power Supply and Distribution System subsystems are ungrounded and have ground detection alarms.
The subsystems are designed so that the batteries cannot be paralleled. Each battery and its seismically qualified racks and hold-down bolts are designed to Seismic Class I standards.
0 erational Re uirements The operability requirements for Unit 1/2 250-volt DC control power supplies A, B, C, and D are prescribed in Unit 2 TS 3.9.A.4. TS 3.9.A.4 requires that 250-volt DC control power supplies A, B, C, and D be operable to allow power operation. During refueling, the 250-volt DC control power supplies are to be operable as necessary for supporting equipment needed for maintaining safe shutdown.
TS 3.9.B.S provides out-of-service action requirements for the Unit 1/2 shutdown board control power supplies.
S ecifics of Pro osed TS Chan e To allow modifications to the Unit 1/2 250-volt DC control power supplies while at power, TVA requests the following changes:
Add a new page 3.9/4.9-10a that contains the following changes to TS 3.9.B.S (changes noted in shaded areas):
From and after the date that one of the 250-V shutdown board batteries and/or its associated battery board is found to be <i~nqperab%$ Qfor any reason, continued REACTOR POWER OPERA%'ION is permissible during the succeed~in five days in
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The note will read as follows:
Add a note to the existing 3.9.B.S on page 3.9/4.9-11 indicating that the provisions of TS 3.9.B.S shown on page 3.9/4.9-10a will apply while modifications are being performed on the 250-volt DC control power supplies. The note will read as follows:
Add the following note to TS 3.9.A.4 on page 3.9/4.9-6:
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TVA requests that the changes to the TS be granted for a period of one year. This will allow time to perform modifications to the four Unit 1/2 power supplies and allow time in between power supply out of service periods to perform maintenance and surveillance tests, setup for the next battery replacement, etc. The one year should also allow sufficient, contingency time to handle unforeseen, short-term circumstances (e.g., short term outages, component breakage, scheduling restrictions).
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In order to perform the power supply modifications prior to Unit 3 fuel load, TVA requests that the amendment granting the temporary TS change be issued by December 1, 1994. TVA also requests that the amendment be made effective for the period of January 1, 1995, to December 31, 1995. A conceptual modification schedule is shown in Enclosure 3.
REASON FOR THE PROPOSED CHANGE This temporary change to the Unit 2 TS is requested so that TVA can upgrade the Unit 1/2 250-volt DC shutdown board control power supplies while Unit 2 is operating.
Extending the AOT to allow performance of the control power system upgrades at power will involve substantial cost savings without a significant impact on safety. TVA's evaluation of the cost benefits associated with performing the system upgrades at power is provided in TVA's cost beneficial licensing action (CBLA) analysis (Enclosure 6).
The 250-volt DC shutdown board control power system has been redesigned so that it can handle the new loads added since previous three-unit operation. Modifications to install new components are needed to support Unit 3's return to service in late 1995/early 1996.
An approved design change has been issued to upgrade the 250-volt DC shutdown board control power supply system.
The primary new load to be added is the ATWS mitigation system for Units 1 and 3. Other miscellaneous loads will also be added. In its final configuration, the function of the system and its components will not be changed. To accommodate the load growth requirements, larger capacity batteries, battery chargers, distribution panels, and associated hardware will be necessary. Needed components are on-site and ready for installation.
Additionally, the prompt performance of the system upgrades is needed as soon as practical for the following reasons:
The 250-volt control power batteries will soon need to be replaced since they are approaching the end of their qualified service life. The first battery's qualified service life expires in November 1996.
Installing new components will increase system reliability. A summary of maintenance activities associated with the system batteries is provided in Enclosure 3. As can be seen from a review of the maintenance history, several recent battery malfunctions have occurred. TVA anticipates that the new batteries will have a lower failure rate.
Installing new batteries will reduce the maintenance requirements associated with the old batteries. The old batteries require annual maintenance as they approach
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the end of their qualified service life. The new batteries will require biennial maintenance.
The annual maintenance requires that the batteries be removed from service, thereby reducing their availability. Increasing the maintenance period will improve the system's overall 'availability.
Descri tion of Desi n Chan es Existing Class 1E 250-volt DC shutdown board control power supply batteries A, B, C, D, and 3EB (C6D type 3DCU-9) will be replaced with new Class 1E (C&D type KCR-11) batteries.
Also, associated battery distribution boards, disconnect receptacles, breakers, and cables will be replaced to accommodate the increased output capability of the new batteries and chargers. The new components meet the requirements of applicable TVA design standards and have adequate margin.
The KCR-11 batteries were chosen to handle additional loads needed for multi-unit operation while maintaining an adequate design margin (i.e., the batteries will have excess capacity). When selecting the new batteries, emphasis was given to providing the largest battery that was economically available. The CGD type KCR-11 Battery was chosen as the most practical replacement battery when considering multi-unit operation load requirements, available margin, and economics; The new batteries will have a 1-minute rating of 500 amperes and an 8-hour discharge rating of 410 ampere-hours at a terminal voltage of 210 volts at 77 F.
Due to an increase in the size and weight of the new batteries, new, Seis'mic Class I, three-tier battery racks will be fabricated and installed.
Larger capacity battery chargers will also be installed.
The existing battery chargers have a capacity of 20 amperes. With Units 2 and 3 operating, the chargers will need to have a capacity of at least 22 amperes. In choosing a larger battery charger, the next larger standard size charger was selected. The new charger has a capacity of 50 amperes.
The existing 250-volt DC control power supply distribution panels are rated at 100 amperes and are too small to accommodate load growth. These panels will be replaced by new, 300 ampere 250-volt DC panels.
The existing ground fault detectors for the 250-volt DC control power supplies will be replaced by new detectors that are located on the new distribution panels. Also, the power supplies to the 250-volt DC control power supply system ground fault detectors are being upgraded.
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TVA will replace much of the electrical cables and circuits associated with the 250-volt DC control power supplies (e.g., battery charger circuit breakers and input and output power cables). The cables being replaced will be placed in conduits that are seismically acceptable where appropriate.
Overview of Work Activities The battery replacement and associated hardware modifications need to be performed for all five (5) 250-volt DC shutdown board control power supply subsystems.
TVA intends to first perform the modifications on the Unit 3 "3EB" control power supply during the upcoming Unit 2 refueling outage (no TS change is needed for Unit 3 since Unit 3's fuel has been removed from the reactor vessel). TVA then intends to perform the modifications on Unit 1/2 250-volt DC control power supplies A, B, C, and D while Unit 2 is at power.
The modifications on the Unit 3 3EB control power supply are scheduled for the Unit 2 refueling outage that is currently scheduled to begin in October 1994. The 3EB power supply will not be needed to support operation of safe shutdown equipment during the refueling outage.
Therefore, the modifications can'be performed without impacting the operation of the plant.
As an additional benefit, performing the work on the 3EB control power supply first will allow TVA to verify that the work and testing involved can be completed within the scheduled time frame. This will afford an opportunity to practice the work, ensuring that it can be accomplished smoothly and efficiently. Lessons learned can be factored into work plans and methods to ensure that the work on the Unit 1/2 power supplies proceeds in an orderly manner.
Pending approval of this proposed TS change, the modifications to the Unit 1/2 power supplies will be performed in series on one power supply at a time. The modifications to the first, Unit 1/2 control power supply are scheduled to begin on approximately January 2, 1995.
The remaining power supply modifications will follow promptly while minimizing the impact on the plant; TVA estimates that the modification work and testing on each train will require approximately 45 days to complete.
If TVA discovers that the 45 days is insufficient as a result of performing the modifications to the 3EB power supply, a supplement to this amendment request will be provided.
TVA estimates that a 2-week period in between each modification/testing period is needed to prepare for the work and conduct maintenance and testing. This 2-week
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period extends the time needed to perform modifications on each power supply to approximately two months each. Since there are four power supplies, approximately eight months is needed to perform the work.
An additional four months for contingency purposes (e.g.,
short duration outages, equipment repairs) is built into TVA's schedule to ensure that unforeseen circumstances can be handled without additional impact on NRC and TVA resources. Therefore, the temporary TS change is needed for a period of one year.
For each train, TVA will establish the necessary pre-conditions, enter the AOT, perform the modifications and testing, and exit the AOT when the power supplies are ready for operation. While the power supply modifications are in progress, work is planned to be performed 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />s-a-day, seven days-a-week.
The following pre-condition restrictions and/or compensatory measures will be in effect during the time that 250-volt DC shutdown board control power supply modifications are in progress:
PLANNED MAINTENANCE (CORRECTIVE OR PREVENTIVE) There will be no planned maintenance on any of the safety 250-volt DC power supplies (plant DC power and related shutdown board control power) that could affect their operation. Planned maintenance will be limited to those periods between control power supply modification outages. Additionally, there will be no planned maintenance activities which would render critical safety equipment (e.g., diesel generators, emergency core cooling system pumps) out of service unless authorized by the Plant Manager. TVA will develop a list of critical safety equipment within the scope of this limitation.
UNPLANNED MAINTENANCE (CORRECTIVE) Unplanned corrective maintenance will not be performed on critical safety equipment unless'ecessary to restore operability. This unplanned maintenance will receive the highest priority. Maintenance activities on critical safety equipment will be performed within the AOTs provided in the plant technical specifications.
Every effort will be made to minimize the amount of time maintenance is performed on critical safety equipment.
SURVEILLANCE TESTING Testing on the 250-volt power supplies (both plant DC power and shutdown board control power) and critical safety equipment will be scheduled around control power supply modification outage periods where possible. Daily, weekly, and monthly surveillances will continue to be performed in accordance with TS requirements at their specified
I frequency. None of these surveillances require that a 250-volt DC power supply be taken out of service.
Surveillance testing performed at quarterly or longer frequencies will be scheduled around modification periods where possible. Plant Manager authorization will be required to performduring these surveillances on critical safety equipment a power supply modification period.
PRE-JOB BRIEFINGS Pre-job briefings will be conducted prior to beginning modifications on each power supply.
These briefings will be held to ensure that individuals are familiar with the scope of the work, knowledgeable of their responsibilities, and aware of the hazards involved.
PROCEDURES AND TRAINING Modification work is performed in accordance with approved procedures/work instructions. Personnel performing work are qualified in accordance with applicable TVA requirements.
Training and procedure(s) will be provided to operations personnel describing the actions to be taken volt DC power supply failure occurs while it if is a 250-supplying shutdown board control power loads. Plant operating personnel (i.e., Shift Operations Supervisor, Assistant Shift Operations Supervisor, Senior Reactor Operators, Reactor Operators, and affected Assistant Unit Operators) will be appropriately trained in the use of the procedure(s) prior to their assuming operator responsibilities while control power supply modifications are in progress.
TEMPORARY POWER SUPPLY CABLE If a 250-volt plant DC power supply malfunctions while it is supplying shutdown board control power, the normal plant loads can be transferred to their alternate power supplies. However, control power will be lost to the affected shutdown boards. Therefore, a temporary power supply cable will be staged and made available so that control power can be restored to the shutdown boards. The appropriate procedures/work instructions will be developed to describe the actions to be taken in the unlikely event use of this restorative feature is necessary.
TVA estimates that the actual modification work on each train will require approximately 40 days to complete. The following summarizes the major work activities and shows the approximate time needed for each.
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WORK ACTIVITY APPROXIMATE DURATION 1 ~ Remove existing equipment 3 Days 2 ~ Prepare rooms (e.g., coating) 5 Days
- 3. Install new equipment 25 Days Battery Racks Distribution Panels Cabling Breakers Battery Charger 4 ~ Install new batteries 2 Days
- 5. Contingency ~5Da a TOTAL 40 ' DAYS The post modification testing is anticipated to take approximately 5 days. The following summarizes the major test activities and shows the approximate time needed for each.
TEST ACTIVITY APPROXIMATE DURATION Calibration and Verification 1 Day Calibrate meters Load test charger Cell connection resistance verification
- 2. Initial Equalization Charge 1 Day 3 ~ Initial Discharge Test 1 Day Specific Gravity Cell Voltage Equalizing Charge 1.5 Days Recharge Battery-Specific Gravity Cell Voltage
- 5. Contingency ~0.5 Da a TOTAL 5 0 DAYS Based on recent battery system work at BFN, TVA has a high level of confidence that the battery systems will perform properly when installed and that the work can be completed within schedule estimates. TVA has gained recent
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experience installing and testing batteries at BFN. The following provides a representative list of batteries recently replaced (all ratings shown are the 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />, ampere-hour discharge rate):
BATTERY SIZE DATE REPLACED Unit Battery g1 2320 A-H 09/90 Unit Battery g2 2320 A-H 05/93 Unit Battery g3 2320 A-H 03/93 EDG Battery A 250 A-H 11/92 EDG Battery B 250 A-H 10/92 EDG Battery C 250 A-H 11/92 EDG Battery D 250 A-H 10/92 EDG Battery 3A 250 A-H 01/93 EDG Battery 3B 250 A-H 09/92 EDG Battery 3C 250 A-H 01/93 EDG Battery 3D 250 A-H 09/90 The new control power batteries were factory tested prior to shipping. Certification documents regarding factory testing have been received and approved. All batteries has recently replaced at BFN were manufactured by C&D. TVA experienced no failures of any of the new battery banks upon installation. Therefore, TVA has a high level of confidence that the new 250-volt DC control power batteries will pass the acceptance tests upon installation.
III'AFETY ANALYSIS Back round The safety objective of the 250-volt DC Power Supply and Distribution System is to provide a highly reliable source of control power and motive power for the Engineered Safeguards System (ESS) so that no single credible event can disable the containment isolation and core standby cooling functions and their supporting control power sources and circuits. The system is arranged and powered so that the probability of power failure to any single battery board bus or shutdown board control bus is very low and that such a failure does not result in loss of any safeguards function. The system is'designed to meet the intent of the XEEE criteria for nuclear power plant protection systems (IEEE-279). The following are the safety design bases for the 250-volt Power Supply and Distribution System (FSAR 8.6.2):
The 250-volt DC power system is designed with adequate independence and redundancy so that the failure of any single active component will not prevent the required ESS from functioning.
Battery capacity is adequate so that any two unit batteries (250-volt plant DC power supplies) can supply for 30 minutes, without chargers available, the DC power
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required to operate the ESS on any one reactor unit in the event of a design basis accident, as well as the DC power required for the safe shutdown and cooldown of the other two units. with a final .terminal voltage of 210 volts.
The ESS that are supplied from the 250-volt DC power system are designed to operate at the required minimum voltage for individual components.
The safety related portion of the ESS 250-volt DC power system is capable of withstanding the Design Basis Earthquake without impairment of its function.
The ESS 250-volt DC power system is designed so that any component, including battery charger, battery, distribution center, and interconnecting wiring, can be tested without disabling any required ESS.
Each shutdown board is supplied 250-volt DC control power from a normal (250-volt DC control power supply) or an alternate safety-related source (250-volt plant DC power supply). The 250-volt DC power supplies (both shutdown board control power and plant DC power) are normally energized by their associated battery charger. The system batteries are backup power sources needed for battery charger malfunctions and loss of offsite power events until the EDGs start and load.
A listing of the normal and alternate control power feeds for each of the Unit 1/2 shutdown boards is provided in Table 1-1. As sho'wn, the 250-volt plant DC system supplies alternate control power for the Unit 1/2 480-volt and 4160-volt shutdown boards. The normal and alternate feeds for the nonsafety-related ATWS mitigation system are also shown. As shown, separate 250-volt control power supplies provide the normal and alternate feeds for the ATWS mitigation system.
A representative listing of the safety-related loads requiring DC control power is provided in Table 1-2. The loads listed are those supplied by 4160-volt shutdown board A and/or 480-volt shutdown board 1A. The loads shown are typical of the safety-related=loads for the remaining"-
Unit 1/2 shutdown boards.
In addition to the loads supplied by the Unit 1/2 shutdown boards, several shared systems and components needed to support Unit 2 operation are fed from the Unit 3 shutdown boards. These systems and components are listed in Table 1-3. The normal and alternate power supplies, where applicable, for these loads are provided. Control power for the specified normal and alternate power supplies is provided by the 250-volt plant DC system or 250-volt DC control power supply 3EB. Performing modifications on the
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Unit 1/2 250-volt DC control power supplies will not affect control power for these components.
Safet Assessment To ensure that a reliable source of control power is available to the shutdown boards while the modifications are in progress, control power for the affected shutdown boards will be provided by their alternate power supply (250-volt plant DC power). In order to ensure that a reliable source of. power is available to the ATWS mitigation system while the modifications are in progress, power for the affected division will be provided by its alternate power supply (250-volt DC control power).
TVA has determined that the alternate power supplies (both 250-volt plant DC power and 250-volt control power) have adequate capacity to supply loads under normal and accident conditions. Calculations were performed to show that normal and accident electrical loading on the alternate sources is acceptable. All cables used for the alternate feeds have been evaluated for ampacity, voltage drop, short circuit, and protection considerations and determined to be acceptable.
As described in the previous section, new batteries were recently installed in the 250-volt plant DC power supply system. The new batteries provide an increased level of confidence that the system will be able to perform its safety function.
While a shutdown board's control power is being supplied by a 250-volt plant DC power source, except for situations related to the operation of the BFN accident mitigation systems (i.e, engineered safeguards features actuation systems), divisional electrical separation will be preserved. This ensures that safety functions will be maintained if a single failure were to occur.
For example, the Core Spray System and the RHR System use four pumps each. The Unit 2 Core Spray System consists of two loops, each loop containing two 504 capacity pumps.
The RHR System consists of four 33-1/34 capacity pumps.
Each of the system's four pumps is fed from a separate shutdown board. In the unlikely event 250-volt DC control power is lost to one board due to a 250-volt plant DC power supply malfunction, only one pump in each system is taken out of service. Therefore, 1004 capacity in each system would be available.
The BFN accident mitigation systems are separated into two divisions. Each division is powered by a 250-volt plant DC power supply. While a 250-volt plant DC power supply is providing control power to a shutdown board, a potential exists that both divisions of some equipment needed to
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respond that to an accident would be temporarily unavailable fails during an accident.
if power supply For example, while the modifications are in progress, a plant DC power supply may be providing power to a Division 1 accident mitigation system and backup control power to a shutdown board that supplies Division 2 components. If an accident were to occur and that power supply fails, the Division 1 components needed to respond to the accident would not receive their actuation signal and the Division 2 components powered by the shutdown board would be without control power.
Any safety system unavailability would only be for a short period of time because the affected accident mitigation systems could be transferred to their alternate power supply using manual switches. This would restore power to the accident mitigation system and result in the appropriate initiation signals.
TVA considers that the risks associated with a simultaneous 250-volt plant DC power supply failure and an accident are acceptable while the shutdown board modifications are in progress. There is an extremely low probability that. an accident and a selected plant DC power supply failure will occur simultaneously or within close proximity. TVA's analysis of this situation is included in a Probabilistic Safety Assessment prepared to support the proposed change (Enclosure-5). "
By design, a fault on one 250-volt plant DC power supply could not affect another 250-volt plant DC power supply.
Electrical calculations have been performed to demonstrate that adequate coordination exists when the 4160-volt and 480-volt shutdown boards are connected to their respective alternate sources of control power (i.e., 250-volt plant DC power). Therefore, volt DC shutdown it board is unlikely that a fault in a 250-control power supply would propagate to a plant DC power supply. In the unlikely event that a fault would occur, the 250-volt plant DC power system is designed so that any two of the three power supplies would be available for safe shutdown.
Another important feature at BFN, with Units 1 -and 3 defueled, concerns the ability to use some Unit 1 and 3 safety equipment to support Unit 2 operation/safe shutdown.
For example, Unit 3 EDGs and associated shutdown boards, and two RHR pumps from an adjacent unit are required to support Unit 2. This feature provides added assurance that safety equipment will be available to respond to unforeseen circumstances in Unit 2.
Unit 1 and 3 support equipment is controlled in accordance with the BFN Unit Separation Program. This program prescribes the measures used to control Unit 1 and 3
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equipment being used to support Unit 2 operation/safe shutdown. The program requires that reviews and approvals be obtained from the appropriate Unit 2 personnel to ensure that the equipment is available to respond to transients or accidents. The Unit Separation Program also prescribes the measures used to ensure that personnel involved in Unit 3 recovery activities do not adversely impact equipment needed for Unit 2.
The 250-volt DC shutdown board control power supply batteries are not credited in the BFN station blackout (SBO) analysis prepared in accordance with 10 CFR 50.63, Reg. Guide 1.155 and NUMARC-8700. The shutdown board control power batteries supply control power for 4160-volt and 480-volt equipment that would not be available during an SBO event. The BFN SBO only credits Unit Batteries (250-volt plant DC power system).
Should an SBO event occur while the shutdown board control power supplies are on their alternate supply, existing plant procedures require operators to reduce loads as necessary. Since shutdown board control power would not be needed, these loads would be quickly removed from the unit batteries. A single failure of HPCI, RCIC, a battery bank, or any other piece. of equipment capable of mitigating the SBO is not part of the design basis for an SBO event per NUMARC-8700 Section 2.4.1(4). Therefore, the modifications to the shutdown board control power supplies do not impact TVA's analysis of the BFN SBO event.
Temporary cables will be provided for the duration of the modification. The temporary cables will allow connection of a secondary source of control power for shutdown boards associated with a power supply that is undergoing modification. This will enhance the ability to respond to situations that could degrade the normal control power to safety related components.
The temporary cable will be adequately sized to carry the shutdown board control loads normally supplied by the shutdown board battery that is out of service. The temporary cables will be sized and staged in a manner to ensure that they do not adversely affect any existing safe shutdown functions at Browns Ferry.
A Special Operating Instruction (SOI) will be developed to address actions to be taken while the shutdown board control power modifications are'in progress. The SOI will address potential equipment degradation effects and describe restoration strategies in the unlikely event an alternate power supply malfunctions. The SOI will also include instructions on placing accident mitigation systems on their alternate power supplies to maximize divisional separation. Training will be provided to ensure that operations personnel are aware of their responsibilities
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and actions if equipment malfunctions occur while modifications are in progress.
Extending the existing AOT constitutes a slight increase in risk. A Probablistic Safety Assessment (PSA) (Enclosure 5) was performed to address the risks associated with the proposed TS change. The results of the PSA indicate that the increase in the core damage frequency is acceptable.
The PSA indicates a 0.3 percent increase in core damage frequency for the proposed TS change. TVA considers this increase insignificant and well within the uncertainty bounds of the PSA.
~Summar TVA considers that extending the 250-volt DC shutdown board control power supply AOT to 45 days will not adversely impact the health and safety of the public. The planned modifications will increase the capacity and reliability of the 250-V DC Shutdown Board Battery System resulting in a net safety benefit. The proposed temporary amendment would allow the power supplies to be replaced without requiring an extension to a Unit 2 refueling outage. The following considerations justify performance of the modifications while Unit 2 is operating:
Units 1 and 3 will be defueled during the modification.
This results in reduced electrical loading on the batteries.and excess-capacity being available.
All safety systems will have power available during the proposed modifications.
Only one shutdown board control power supply will be removed from service at a time.
At no time during a modification period will any of the three unit power supplies be removed from service for planned maintenance.
250-volt DC control power will be provided through qualified, alternate safety-related power supplies.
Performing the proposed 250-volt DC System modification will increase system reliability and is required for multi-unit operation due to an increase in loads.
TVA's Probabilistic Safety Assessment shows that there is an insignificant increase in risk associated with the proposed amendment.
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e I' TABLE 1-1 250-VOLT DC SHUTDOWN BOARD CONTROL POWER SUPPLY SYSTEM NORMAL AND ALTERNATE SOURCES NORMAL ALTERNATE DC LOAD 250-VOLT DC 250-VOLT DC SOURCE SOURCE 4160-volt Shutdown Board Control Power Plant DC Power A Control Power Supply "A" Supp ly II 2 II 480-volt Shutdown Board Control Power Plant DC Power lA Control Power Supply "A" Supply II 2 II 4160-volt Shutdown Board Control Power Plant DC Power II 2 If II Bll Supply B Control Power Supply 480-volt Shutdown Board Control Power Plant DC Power 2A Control Power Supply "B" Supply "1" 4160-volt Shutdown Control Power Plant DC Power Board C Control Power Supply "C" Supply II 1 II 480-volt Shutdown Board Control Power Plant DC Power 1B Control Power Supp ly II C II Supply "3" Unit 2 ATWS Normal Control Power Control Power Channel A Supply "C" Supply "A" 4160-volt Shutdown Board Control Power Plant DC Power D Control Power Supp ly II Dll Supply II 3 II 480-volt Shutdown Board. Control Power Plant DC Power 2B Control Power Supply "D" Supply II 3 II Unit 2 ATWS Normal Control Power Control Power Channel B Supply "D" Supply IIBII 4160-volt Shutdown Board Control Power Plant DC Power Supply ll 3 II 3EB Control Power Supply >>3EB 4160-volt Shutdown Board Plant DC Power Plant DC Power 3EA Supply II 1 II Supply, ll 2 II 480-volt Shutdown Board Plant DC Power Plant DC Power 3A Supply "1" Supply "2" 4160-volt Shutdown Board Plant DC .Power Plant DC Power tt3 II Supp] y II 1 II 3EC Supply 480-volt Shutdown Board Plant DC Power Plant DC Power 3B Supply "3" Supply II 1 II 4160-volt Shutdown Board Plant DC Power Plant DC Power 3ED Supply II 2 II Supp ly If 3 II E1-20
TABLE 1-2 4160-VOLT SHUTDOWN BOARD A & 480-VOLT SHUTDOWN BOARD 1A TYPICAL CONNECTED LOADS CONNECTED LOADS 4160V Shutdown Board A 480V Shutdown Board 1A CORE SPRAY PUMP 1A NORMAL FEED FOR CONTROL BAY VENT BOARD A CORE SPRAY PUMP 2A 250V BATTERY CHARGER 1 RESIDUAL HEAT REMOVAL CONTROL AND SERVICE AIR (RHR) PUMP 1A COMPRESSOR A RHR PUMP 2A NORMAL FEED FOR REACTOR MOTOR OPERATED VALVE (RMOV) BOARD 1D RHR SERVICE WATER PUMP Al CONTROL BAY WATER CHILLER A RHR SERVICE WATER PUMP A2 EMERGENCY FEED FOR RMOV BOARD 1E RAW COOLING WATER PUMP 1D CLOSED COOLING WATER PUMP 1A CONTROL ROD DRIVE REACTOR WATER CLEANUP HYDRAULIC FEED PUMP 1B RECIRCULATION PUMP 1A 480V SHUTDOWN BOARD 1A RECIRCULATION MOTOR-GENERATOR (MG) SET OIL PUMP 1A-1 480V DIESEL AUX BOARD A RECIRCULATION MG SET OIL PUMP 1B-1 FIRE PUMP A STANDBY LIQUID CONTROL PUMP 1A FUEL POOL COOLING PUMP 1A DRYWELL BLOWER 1A-1 DRYWELL BLOWER 1B-1 El-21
TABLE 1-3 UNIT 3 LOADS REQUIRED FOR UNIT 2 OPERATION The following loads are powered by the Unit 3 shutdown boards and are required to support Unit 2 safe shutdown. Power supplies for each load are denoted:
o Emergency Equipment Cooling Water (EECW) pumps 4160-volt Shutdown Board 3EA and/or 4160-volt Shutdown Board 3EB o Standby Gas Treatment Train "C" 4160-volt Shutdown Board 3ED o Control Room Emergency Ventilation System (CREVS) 4160-volt Shutdown Board 3EB or 4160-volt Shutdown Board 3EC o Shutdown Board Rooms and Control Bay HVAC 4160-volt Shutdown Board 3EC 480 Shutdown Board 3B The power supplies shown above are listed to show their typical lineup. Each lineup can be varied depending on which diesel generator associated with Unit 3 is operable.
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IV. NO SIGNIFICANT HARARDS CONSIDERATION DETERMINATION The proposed change involves temporarily (one-year period) extending the 5-day allowed outage time (AOT) for the 250-volt DC shutdown board control power supplies specified in Technical Specification (TS) 3.9.B.8 to 45 days. TVA has concluded that operation of Browns Ferry Nuclear Plant (BFN) Unit 2 in accordance with the proposed change does not involve a significant hazards consideration. TVA's conclusion is based on its evaluation, in accordance with 10 CFR 50.91(a)(1), of the three standards set forth in 10 CFR 50.92(c).
- 1. The ro osed amendment does not involve a si nificant increase in the robabilit or conse uences of an accident reviousl evaluated.
The proposed change involves temporarily (one-year period) extending the 5-day AOT for the 250-volt shutdown board control power supplies to 45 days. As such, this change does not increase the probability of any accident previously analyzed.
The 250-volt DC Power System is required to function to mitigate the consequences of design basis accidents.
The loss of a single 250-volt DC shutdown board control power supply will result in a loss of control power for the 480-volt and the 4160-volt shutdown board that it serves. Loss of control power results in loss of only those engineered safeguards supplied by its respective shutdown boards. Redundant safe shutdown equipment exists to mitigate the consequences of design basis accidents. As discussed in Final Safety Analysis Report (FSAR) subsection 8.6.4.3, a single failure of a shutdown board control power supply is acceptable.,
Loss of a single 250-volt plant DC power supply will not prevent Unit 2 safe shutdown. The 250-volt plant DC power supply system is designed so that any two out of the three power supplies carry the entire load needed for safe shutdown. As discussed in FSAR subsection 8.6.4.2 a single failure of a 250-volt plant DC power supply is acceptable.
At no time will control power be unavailable to the shutdown boards during the system upgrades. The proposed change will only increase the time allowed to operate the plant while a 250-volt DC shutdown board control power supply is out of service.
The proposed TS change allows an additional 40 days to perform system upgrades and results in a small increase in risk. This small increase in risk is associated with the probability and consequences of a 250-volt plant DC power supply malfunction while it is supplying El-23
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shutdown board 'control power. The increase in risk associated with extending the AOT was analyzed in a Probabilistic Safety Assessment (PSA) and determined to be approximately 0.3 percent. This small increase in risk is determined to be insignificant and well within the uncertainty bounds of the PSA.
The proposed TS change does not change the function of any plant structure, system or component. The proposed change allows for improvements to the 250-volt DC shutdown board control power supply system. The improvements will increase the capability and reliability of the system. Qualified backup power will be utilized at all times during system modifications.
Only one power supply will be out of service at a time during the modifications.
The small increase in risk is more than offset by the increased capability, capacity, and reliability of the new power supplies. Therefore, the power supply modifications will result in a net overall safety benefit.
2 ~ The ro osed amendment does not create the ossibilit of a new or different kind of accident from an accident reviousl evaluated.
Extending the 5-day AOT for the 250-volt shutdown board control power supplies to 45 days does not create the possibility of a new or different kind of accident, nor does it increase the probability that an accident will occur. The AOT extension does not involve plant modifications that could create the possibility of a new or different kind of accident from any of those discussed in the FSAR.
The 250-volt DC shutdown board control power supply, modifications involve replacement of the existing components with more reliable, increased capacity equipment having the same functions as before.
3 ~ The ro osed amendment does not involve a si nificant reduction in a mar in of safet The proposed TS. change involves a risk increase of approximately 0.3 percent. TVA considers this small increase to be insignificant. TVA also considers that the small increase in risk is offset by the benefits associated with replacing the control power supplies with new, upgraded equipment. Therefore, the proposed TS change does not involve a significant reduction in a margin of safety.
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ENVIRONMENTAL IMPACT CONSIDERATION The proposed change does not involve a significant hazards consideration, a significant change in the types of or significant increase in the amounts of any effluents that may be released offsite, or a significant increase in individual or cumulative occupational radiation exposure.
Therefore, the proposed change meets the eligibility criteria for categorical exclusion set, forth in 10 CFR an 51.22(c)(9). Therefore, pursuant to 10 CFR 51.22(b),
environmental assessment of the proposed change is not required.
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