ML092520189
| ML092520189 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 09/02/2009 |
| From: | Baxter D Duke Energy Carolinas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LAR 06-009, TAC MD9026, TAC MD9027, TAC MD9028 | |
| Download: ML092520189 (63) | |
Text
Duke DA VE BAXTER Vice President Ave Energy. Oconee Nuclear Station Duke Energy ON01 VP / 7800 Rochester Highway Seneca, SC 29672 864-873-4460 September 2, 2009 864-873-4208 fax dabaxter@dukeenergy.com U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555-0001
Subject:
Duke Energy Carolinas, LLC Oconee Nuclear Station Renewed Facility Operating Licenses Numbers DPR-38, DPR-47, and DPR-55; Docket Numbers 50-269,-50-270, and 50-287 Responses to Request for Additional Information for the License Amendment Request to Revise Portions of the Updated Final Safety Analysis Report Related to the Tornado Licensing Basis; License Amendment Request: 2006-009
References:
- 1. Letter from Dave Baxter, Site Vice President, Oconee Nuclear Station, Duke Energy Carolinas, LLC, to the U. S. Nuclear Regulatory Commission, "License Amendment Request to Revise Portions of the Updated Final Safety Analysis Report Related to the Tornado Licensing Basis," dated June 26, 2008.
- 2. Letter from John Stang, Project Manager, Office of Nuclear Reactor Regulation, U. S.
Nuclear Regulatory Commission, to Dave Baxter, Site Vice President, Oconee Nuclear Station, Duke Energy Carolinas, LLC, "Request for Additional Information Regarding the Licensee amendment Request for Upgrading the Licensing Basis for Tornado Mitigation (TAC NOS. MD9026, MD9027, MD9028)," dated July 6, 2009.
On June 26, 2008, Duke Energy Carolinas, LLC (Duke) submitted a License Amendment Request (LAR) to revise certain sections of the Oconee Updated Final Safety Analysis Report (UFSAR) associated with the tornado licensing basis [Ref. 1]. Specifically, this LAR proposes a number of plant modifications to enhance the station's capability to withstand the effects of a damaging tornado, revises the UFSAR sections associated with the tornado licensing basis (LB), and incorporates the tornado missile probabilistic methodology (TORMIS).
On July 6, 2009, Duke received a Request for Additional Information (RAI) in regards to the LAR [Ref. 2]. This submittal contains Duke's responses to that RAI. Within this document, the attachment contains Duke's responses to the RAI and supporting documentation is provided in the enclosure.
If you have any questions in regard to this letter, please contact Stephen C. Newman, Regulatory Compliance Lead Engineer, Oconee Nuclear Station, at (864) 873-4388.
www. duke-energy. corn
U. S. Nuclear Regulatory Commission Responses to NRC Request for Additional Information September 2, 2009 Page 2 1 declare under penalty of perjury that the foregoing is true and correct.
Executed on September 2, 2009.
Sincerely, Dave Ba. ter, Vice President Oconee Nuclear Station
Attachment:
Duke Responses to RAI.
Enclosure:
Tables, Drawings, and Diagrams
U. S. Nuclear Regulatory Commission Responses to NRC Request for Additional Information September 2, 2009 Page 3 bc w/attachment/enclosure:
Mr. J. F. Stang, Project Manager Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 0- 14 H25 Washington, D. C. 20555 Mr. L. A. Reyes, Regional Administrator U. S. Nuclear Regulatory Commission - Region II Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, GA 30303-8931 Mr. Curtis W. Rapp Sr. Project Engineer, Branch 1, DRP U.S. Nuclear Regulatory Commission - Region I1 Sam Nunn Atlanta Federal Center, 23 T85 61 Forsyth St., SW Atlanta, GA 30303-8931 Mr. Andy Sabisch NRC Senior Resident Inspector Oconee Nuclear Station S. E. Jenkins, Manager Infectious and Radioactive Waste Management Section 2600 Bull Street Columbia, SC 29201
U. S. Nuclear Regulatory Commission Responses to NRC Request for Additional Information September 2, 2009 Page 4 bcc w/attachment/enclosure:
R. C. Meixell R. M. Glover G. K. Mc Aninch L. M. Kanipe T. P. Gillespie, Jr.
S. L. Batson J. E. Burchfield R. J. Freudenberger R. L. Gill - NRI&IA R. D. Hart- CNS K. L. Ashe - MNS NSRB, EC05N ELL, EC050 File - T.S. Working ONS Document Management
Attachment Duke Responses to RAI
Attachment - Duke Responses to RAI License Amendment Request No. 2006-009 September 2, 2009 Page 1 RAI -1 Provide the following information for the new protected service water (PSW) transformer, switchgear, load center and the circuit breakers: 1) equipment design ratings, 2) a summary of the analyses preformed to show the loading, short circuit values and the interrupting ratings, voltage drop, and protection and coordination, 3) the existing station auxiliary service water (ASW) switchgear ratings, and 4) the periodic inspection and testing requirements for electrical equipment. Provide applicable schematic and single line diagrams.
Duke Response Note: As of the date of this response, various aspects of the PSW's design, including equipment rating and parameters, are not final and are subject to change. In addition to the information below, specific details related to the PSW design features will be made available for future inspection at the Oconee Nuclear Station.
- 1. The 13.8kV/4.16kV switchgear is a double ended unit substation. Each unit substation consists of normal and alternate 13.8kV power source breakers, a 13.8kV/4.16kV step down transformer, and a 4.16kV main breaker connected to its respective 4.16kV switchgear buss.
The two 4.16kV switchgear busses may be connected through a 4.16kV tie breaker.
Switching power source breakers is performed by manual dead bus transfer. The design ratings for the PSW electrical equipment are as follows:
- a. 13.8kV/4.16kV Unit Substation Each ABB transformer is 13.8/4.16kV, 10/13.3MVA, 60Hz, 3 phase, solid cast, dry type transformer complete with neutral grounding resistor, AA-FA 133% overload rating with temperature monitor, NEMA 1 enclosure, and 185 degree C insulation class. The transformer primary is 13.8kV delta, 110kV BIL, and the secondary is 4.16kV wye, 75kV BIL. There are a total of five taps non-load changing (-5%, -2.5%, 0%, +2.5%,
and +5%).
The 13.8kV Square-D switchgear is a 1200A silver-plated copper bus in a NEMA 1 enclosure with 95kV BIL impulse withstand voltage, minimum short circuit current of 48KA RMS symmetrical, one minute withstand voltage of 36kV RMS. The 4.16kV switchgear is continuous rated 2000A silver-plated copper bus, 3 phase, 3 wire, low resistance grounded wye, 4.16kV nominal, 4.76kV maximum, minimum short circuit current 49KA RMS symmetrical, impulse withstand voltage 60kV BIL, one minute withstand voltage of 19kV RMS.
The 13.8kV Square-D switchgear breakers are 15kV maximum voltage nominal system voltage 13.8kV, 3 phase, 3 wire, IOOOMVA, 1200A. The 4.16kV Square-D switchgear main and tie breakers are 4.76kV maximum, 350MVA, and 2000A. The Square-D feeder breakers are 4.76kV maximum, 350MVA, and 1200A.
Attachment - Duke Responses to RAI License Amendment Request No. 2006-009 September 2, 2009 Page 2
- b. 600VAC Load Center The 600VAC load center ABB transformer is 4.16kV/600VAC, 5MVA, 60Hz, 3 phase, delta - wye cast coil dry type transformer with solidly grounded neutral, NEMA 1 enclosure, 80 degree C temperature rise, and insulation class of 220' C.
The 600VAC Square-D switchgear is 3 phase, 4 wire, solidly grounded neutral, 5000A copper bus.
The 600VAC Square-D load center main breaker is 600VAC, 5000A with Power Metering type 6.OP Micrologic Trip Unit, 5000A sensor plug, and an A rating plug.
Feeder breakers are 600VAC, 1600A or 800A, with Power Metering Type 6.OP Micrologic Trip Units, with a 1200A/600A/400A sensor plug and with A/C/G rating plugs.
- 2. Loading, short circuit values, interrupt ratings, and voltage drops for the PSW transformer, switchgear, load center, and circuit breakers will be analyzed in an Electrical Transient Analysis Program (ETAP) calculation associated with PSW design packages, which are under development. Protection and coordination for the PSW transformer, switchgear, load center, and circuit breakers will be in accordance with Duke and industry standards. Details will be prepared in a separate calculation.
- 3. The existing station Auxiliary Service Water (ASW) switchgear breaker ratings are four (4) 1200A breakers, and four (4) 600A breakers (Ref. dwg 0-702-A l).
- 4. The PSW transformer, switchgear, load center, and circuit breakers will be periodically inspected, maintained, and tested in accordance with the Duke Nuclear Fleet, vendor, and industry (e.g. EPRI) recommendations, to maintain equipment reliability and qualification, and to satisfy Technical Specification surveillance requirements.
Applicable schematic and single line diagrams [Enclosure] are:
- 0-702-Al - One Line Diagram 6900V & 4160V Station Auxiliary System
[The following drawing is PRELIMINARY and has not been approved]:
& 0-6700 - One-Line Diagram Main PSW Switchgear
- 0-6707 - One-Line Diagram 600V PSW Bldg, MCC XPSW Loadcenter OCPSW1 RAI -2 Provide the following information concerning the proposed PSW instrumentation and control (I&C) power and the interface with the existing plant vital I&C power: 1) design of the DC
Attachment - Duke Responses to RAI License Amendment Request No. 2006-009 September 2, 2009 Page 3 system for the PSW system including how the DC control power for the new PSW load center, switchgear and the transformer will be provided, 2) the impact on existing DC vital system including loading on the existing battery and the battery charger, 3) describe the analysis performed to determine the capacity of the batteries and the battery charger, voltage requirements at the equipment terminals, electrical protection and co-ordination, and 4) the periodic inspection and testing requirements. Provide applicable schematic and single line diagrams.
Duke Response Note: As of the date of this response, various aspects of the PSW's design, including equipment rating and parameters, are not final and are subject to change. In addition to the information below, specific details related to the PSW design features will be made available for future inspection at the Oconee Nuclear Station.
- 1. The PSW DC system includes two batteries, two battery chargers, one 125 VDC distribution center, 125 VDC panels located in the PSW building and plant, a DC ground detector and battery test boxes.
Each battery consists of 60 C&D LCY-39 flooded lead-acid cells with one battery aligned to the PSW DC system at a time and the other battery maintained on float voltage in standby and isolated from the PSW DC system.
The two 300 ADC battery chargers are manufactured by SCI/AMETEK. The PSW DC system design will allow either charger to be aligned to either battery.
The PSW DC system will provide DC control power to the PSW switchgear and load centers via the 125 DC PSW distribution center and panels and also provide DC control power for new PSW equipment located in the plant.
- 2. Additional loading imposed by new PSW components on the existing plant Vital I&C DC system is minimal ADC and consists of new main control room indication and power supplies. The majority of the new DC PSW loads will be fed from the PSW DC system and there will be no electrical interconnection between the PSW DC and existing Vital I&C DC systems.
- 3. The analysis used for selecting the battery and battery charger sizes and ratings is found in preliminary calculation OSC-9190 (Protected Service Water DC System Analysis Calculation).
The battery size was conservatively selected using IEEE-485 and including as a design requirement the ability to jumper out up to two cells from the nominal 60 cell battery while still maintaining sufficient capacity to feed the design basis load. Additionally, the IEEE-485 methodology resulted in a selected cell size of LCY-37 which was increased to LCY-39
Attachment - Duke Responses to RAI License Amendment Request No. 2006-009 September 2, 2009 Page 4 which provides additional design margin for the PSW DC system.
The battery charger size was selected using IEEE-946 methodology and is based on a battery recharge time of eight (8) hours. Battery terminal voltage is based on a minimum value of 105 VDC. PSW DC system protection and coordination will be included in other calculations associated with PSW design packages which are under development.
PSW DC system protection and coordination will be in accordance with industry and Duke standards.
- 4. The PSW DC system will be periodically inspected, maintained and tested per vendor and industry (e.g. EPRI) recommendations to maintain equipment reliability and qualification and satisfy Technical Specification surveillance requirements.
The PSW batteries will undergo weekly, monthly, quarterly and annual battery surveillances and inspection including voltage, specific gravity, electrolyte level and temperature, battery condition and service and performance discharge tests. Battery racks will also be subject to periodic inspection and maintenance.
The PSW Battery chargers will undergo periodic inspections and testing such as float and equalization voltage adjustment, circuit board calibration, cleaning and periodic parts replacement and load testing.
The PSW 125 VDC distribution center, panels and ground detection system will undergo periodic testing, calibration and cleaning.
Applicable schematics and single line diagrams are: 0-6700-01, 0-6701, 0-6702, and 0-6703.
RAI -3 In Enclosure 2, Section 3.3.4 of the LAR, the licensee states that the Keowee Hydroelectric Units (KHUs) will provide power supply to the PSW switchgear through underground cables.
Provide analyses to show the kilo volt ampere (kVA) loading, new circuit breaker rating, short circuit values, and voltage drop. In addition, provide information on the electrical protection and coordination, and the periodic inspection and testing requirements. Further, explain how the redundancy and independence of the Class 1E power system is maintained as a result of the proposed modification. Provide applicable schematic and single line diagrams.
Attachment - Duke Responses to RAI License Amendment Request No. 2006-009 September 2, 2009 Page 5 Duke Response Note: As of the date of this response, various aspects of the PSW's design, including equipment rating and parameters, are not final and are subject to change. In addition to the information below, specific details related to the PSW design features will be made available for future inspection at the Oconee Nuclear Station.
- 1. The loading, short circuit values, interrupt ratings, and voltage drops for the underground cables will be analyzed in an Electrical Transient Analysis Program (ETAP) calculation associated with PSW design packages, which are under development.
- 2. Protection and coordination for the underground cables will be in accordance with industry and Duke standards. Details will be prepared in a separate calculation.
- 3. The underground cables will be evaluated for inclusion in the Oconee Nuclear Station (ONS) Insulated Cables and Connections Aging Management Program where periodic inspections and testing schedule for these cables will be established (See response to RAI #
6 [below] for additional information).
- 4. The PSW electrical system has a normal (13.8kV Fant Line) and alternate (13.8kV Keowee Hydro Unit) 13.8kV power source breaker to each PSW Unit Substation. The redundancy of the PSW power system is provided through these two power sources. The Keowee Hydro Unit 13.8kV power source cables to the PSW electrical system will be routed in a combination of precast concrete trench boxes, duct banks, and manholes. The power feeds from Keowee Hydro Unit to both Oconee Nuclear Station and the PSW electrical equipment are' isolated by separate breakers and disconnect switches. Independence is maintained as required by Duke Design Criteria DC 3.13.
Applicable schematic and single line diagrams are:
[The following drawings are PRELIMINARY and have not been approved]:
- 0-6700 - One-Line Diagram Main PSW Switchgear
- K-700 - Keowee Hydro Station - One-Line Diagram RAI -4 The licensee states in the LAR that the PSW system will be fully operational from the respective unit's main control room and will be activated when existing redundant emergency systems are not available. Describe how the alarms, indications, and the electrical controls will be provided from the main control rooms of Units 1 and 2 to the proposed PSW
Attachment - Duke Responses to RAI License Amendment Request No. 2006-009 September 2, 2009 Page 6 switchgear. Explain how the controls are provided for Unit 3. Provide applicable electrical schematics and evaluations highlighting the design features.
Duke Response Note: As of the date of this response, various aspects of the PSW's design, including equipment rating and parameters, are not final and are subject tochange. In addition to the information below, specific details related to the PSW design features will be made available for future inspection at the Oconee Nuclear Station.
The PSW pump will be manually started from the Unit 2 Main Control Room. Unit 1, 2, and 3 will control their respective PSW powered injection valves, HPI pumps, and RCS vent valves from their respective control room via power transfer and control switches. All appropriate control and monitoring functions will be alarmed at the plant Operator Aid Computer (OAC) or on the respective Unit's Stat alarm panels. Details will be included in the associated PSW design change packages, which are under development.
Applicable one-line diagrams and electrical schematics highlighting the design features are as follows:
The following drawing is PRELIMINARY and has not been approved.
00-6700 - One-Line Diagram Main PSW Switchgear RAI -5 Provide information on how the licensing basis for physical independence and separation criteria are met for the PSW electrical system.
Duke Response Note: As of the date of this response, various aspects of the PSW's design, including equipment rating and parameters, are not final and are subject to change. In addition to the information below, specific details related to the PSW design features will be made available for future inspection at the Oconee Nuclear Station.
The licensing basis for physical independence and separation criteria for the PSW electrical system meet the requirements of Duke Design Criteria DC 3.13, " Oconee Nuclear Station Cable and Wiring Separation Criteria," that provides guidance for cable routing and installation.
Refer to DC 3.13 [Enclosure].
Attachment - Duke Responses to RAI License Amendment Request No. 2006-009 September 2, 2009 Page 7 RAI -6 The licensee states in the LAR that the new PSW system switchgear will receive power from the KHUs via a tornado-protected underground feeder path. Provide the following information: 1) the type of underground cable installation, i.e., direct burial or in duct banks, manholes etc., 2) how the licensee will ensure that the proposed new underground cables remain in an environment that they are qualified for, 3) periodic inspections and testing planned for cables to monitor their performance, and 4) details regarding cable size, type, maximum loading requirements, and cable protection devices.
Duke Response Note: As of the date of this response, various aspects of the PSW's design, including equipment rating and parameters, are not final and are subject to change. In addition to the information below, specific details related to the PSW design features will be made available for future inspection at the Oconee Nuclear Station.
- 1. The underground cable route from Keowee Hydro to the PSW building will be a combination of precast concrete trench boxes, duct banks and manholes. None of the cables will be direct buried.
- 2. The Keowee underground path to the PSW switchgear will be designed to preclude water entry that could wet the cables. The concrete trenches will have drains. The duct banks will be sloped towards manholes where drains or sump pumps are provided. Periodic inspections will be performed on the Keowee to PSW underground path to evaluate the condition of the trenches, duct banks, manholes and drainage system.
- 3. The cables will be evaluated for inclusion in the ONS Insulated Cables and Connections Aging Management Program. Since the underground path from Keowee to the PSW switchgear cable installation is designed to prevent significant exposure to moisture and is inaccessible, it is expected that the cables will not meet the criteria for periodic diagnostic testing. If subsequent periodic inspection of the Keowee to PSW switchgear underground trenches, duct banks and manholes determines that these inaccessible cables are exposed to significant moisture, testing will be performed.
- 4. The 13.8 kV circuit from Keowee to the PSW switchgear consists of six single conductor cables. Each conductor is 750 kcmil copper with Class B compact round stranding. The conductor shield is a thermoset semi-conducting compound extruded over the conductor.
The insulation is ethylene propylene rubber (EPR) that provides an insulation level of 173% about the 15 kV nominal insulation rating. The insulation is rated at 90'C continuous and 130'C emergency overload. The insulation shield is a semi-conducting thermoset compound extruded over the insulation. Two layers of non-magnetic bronze tape shield are applied over the insulation shield. A thermoset chlorosulfonated
Attachment - Duke Responses to RAI License Amendment Request No. 2006-009 September 2, 2009 Page 8 polyethylene (Hypalon) jacket is applied over the cable core.
Maximum allowable cable loading will be determined by Duke ampacity criteria and engineering calculation. Cable protection will be determined by Duke protective relaying criteria and standard industry practice.
RAI -7 Provide information concerning the design details for the new 100/13.8 kV substation, the PSW transformer and switchgear building power feeds, its protection, controls and alarms features. Provide applicable single line diagram and electrical schematics.
Duke Response Note: As of the date of this response, various aspects of the PSW's design, including equipment rating and parameters, are not final and are subject to change. In addition to the information below, specific details related to the PSW design features will be made available for future inspection at the Oconee Nuclear Station.
The new 100/13.8 kV substation is fed via an overhead 100 kV path from the Duke Lee Central switching station. The substation is a 13.44 MVA 100/13.8 kV oil-filled fan cooled transformer. The transformer primary side is equipped with a circuit switcher that is remotely controlled from the Duke Transmission Control Center (TCC). Various transformer and substation parameters are remotely available to the TCC. The transformer is equipped with secondary side protection.
The 13.8 kV circuit from the substation to the ONS owner controlled area is an overhead path constructed per Duke Power Delivery standards. The 13.8 kV overhead path then transitions to underground duct bank and enters the protected area and PSW building where it terminates at the PSW switchgear. See preliminary one-line diagram 0-6700 for additional details on the Main PSW 13.8/4 kV System.
Refer to 0-6700 - One-Line Diagram Main PSW Switchgear [Enclosure].
RAI -8 The licensee states in Enclosure 2, Figure 1 of the LAR, that two new power feeds will be installed to the auxiliary building (AB) with one power supply to the Unit 1, 2, and 3 AB equipment high pressure injection (HPI) pumps and vital I&C normal battery chargers and other power supply to the backup power to the Units 1, 2, and 3 pressurizer heaters. Provide the following information concerning this installation: 1) compare and contrast the existing power supply requirements for the above loads, 2) how the electrical separation, independence, and redundancy requirements are maintained, 3) summary of the voltage
Attachment - Duke Responses to RAI License Amendment Request No. 2006-009 September 2, 2009 Page 9 analyses for the equipment/components affected by this modification, 4) design details for the new power feeds to AB, 5) periodic inspections and testing schedule for the these cables to monitor their performance, and 6) provide the electrical schematics and one-line drawings for these power feeds.
Duke Response Note: As of the date of this response, various aspects of the PSW's design, including equipment rating and parameters, are not final and are subject to change. In addition to the information below, specific details related to the PSW design features will be made available for future inspection at the Oconee Nuclear Station.
- 1. A comparison and contrast of the existing power supply requirements for the above loads will be performed in a separate calculation associated with PSW design packages, which are under development.
- 2. The electrical separation, independence, and redundancy requirements are maintained in accordance with the requirements of Duke Design Criteria DC 3.13, "Oconee Nuclear Station Cable and Wiring Separation Criteria," that provides guidance for cable routing and installation.
- 3. Analysis of the voltages for the equipment/components affected by this modification will be analyzed in an Electrical Transient Analysis Program (ETAP) calculation associated with PSW design packages, which are under development.
- 4. Design details for the new power feeds to the HPI pump motors, battery chargers, and pressurizer heaters are indicated on the drawings identified in item #6 below.
- 5. The new cables will be evaluated for inclusion in the Oconee Nuclear'Station (ONS)
Insulated Cables and Connections Aging Management Program where periodic inspections and testing schedule for these cables will be established to monitor their performance.
- 6. Electrical schematics and one-line drawings for these power feeds are:
- 0-702 - Unit 1 One-Line Diagram 6900V & 4160V Station Auxiliary System
- 0-1702 - Unit 2 One-Line Diagram 6900V & 4160V Station Auxiliary System 0 0-2702 - Unit 3 One-Line Diagram 6900V & 4160V Station Auxiliary System
[The following drawings are PRELIMINARY and have not been approved]:
- 0-6700 - One-Line Diagram Main PSW Switchgear
Attachment - Duke Responses to RAI License Amendment Request No. 2006-009 September 2, 2009 Page 10
- O-703-D - Unit 1 One-Line Diagram Station Auxiliary Ckts 600V
- 0-703-E - Unit 1 One-Line Diagram Station Auxiliary Ckts 600V
& 0-1703-C - Unit 2 One-Line Diagram Station Auxiliary Ckts 600V
- O-1703-D - Unit 2 One-Line Diagram Station Auxiliary Ckts 600V
- 0-2703-C - Unit 3 One-Line Diagram Station Auxiliary Ckts 600V o O-2703-D - Unit 3 One-Line Diagram Station Auxiliary Ckts 600V RAI -9 Provide confirmation that the maximum float/equalizing voltage does not exceed the equipment maximum DC voltage rating.
Duke Response Note: As of the date of this response, various aspects of the PSW's design, including equipment rating and parameters, are not final and are subject to change. In addition to the information below, specific details related to the PSW design features will be made available for future inspection at the Oconee Nuclear Station.
Duke does not perform online equalization charging on batteries therefore equipment overvoltage will not be a concern since the battery being equalized will be isolated from the DC system. Float voltage setting will be based on vendor recommendations and engineering calculation and controlled by maintenance procedures to ensure that equipment maximum DC ratings will not be 'exceeded.
RAI -10 Describe in detail how the 125 VDC vital I&C primary and backup power cables and the KHU emergency start circuitry will be rerouted from the turbine building (TB) to the AB.
Duke Response Note: As of the date of this response, various aspects of the PSW's design, including equipment rating and parameters, are not final and are subject to change. In addition to the information below, specific details related to the PSW design features will be made available for future inspection at the Oconee Nuclear Station.
All of the Unit 1,2, and 3 125 VDC Vital I&C Battery System primary cables and Unit 1, 125 VDC Vital I&C Battery System backup cables to Unit 3, will be replaced with new cables routed solely inside the Auxiliary Building through areas protected from HELB and Tornado
Attachment - Duke Responses toRAI License Amendment Request No. 2006-009 September 2, 2009 Page II design basis events. The new cable routing will not affect the system functional characteristics and the termination points and each end of the cables will not change.
This design change provides new routing for the Keowee Hydro Units (KHU) emergency start cables. The existing underground spare cables between KHU and the Oconee Station will be used. For tie-in to control and logic, these underground cables will be extended with new cables between KHU termination cabinets to KHU control panels and Oconee termination cabinets to control panels in the Auxiliary Building. New emergency start cables will be installed from the 230 kV switchyard relay house via a new protected underground duct bank to the PSW switchgear building and, underground via protected duct bank, to the Auxiliary Building control panels.
Refer to drawings labeled RAI #10 in the Enclosure.
RAI -11 Provide the following clarifying information concerning the use of the tornado missile probabilistic methodology (TORMIS):
- b. A basis for stating the NRC staff acknowledged Duke's specific application of the TORMIS methodology.
- c. Provide clarification as to the LAR being based on the NRC staff having accepted the probabilistic analysis as the current licensing basis (CLB), for tornado mitigation. If this is correct please provide the documentation stating the acceptance.
Duke Response Duke has utilized the TORMIS methodology in previous responses to tornado missile-related NRC inquiries; however, these submittals did not result in TORMIS being incorporated into the tornado LB. Duke proposes to 'expand' its use by formally incorporating the TORMIS methodology into Oconee's tornado LB.
RAI -12 Provide a basis for the use of the TORMIS methodology in identifying and/or excluding system structures and components (SSC) requiring or not requiring tornado protection as part of the ONS licensing basis.
Duke Response For the proposed Oconee licensing basis, all SSCs supporting the tornado mitigation strategy are protected deterministically; except for specific plant features (addressed by TORMIS) having a sufficiently low probability of damage (collectively) that would otherwise require the
Attachment - Duke Responses to RAI License Amendment Request No. 2006-009 September 2, 2009 Page 12 addition of costly tornado missile protective barriers or other plant modifications in order to meet deterministic protection requirements.
Transitioning from the CLB to the proposed tornado licensing basis, those SSCs requiring additional physical protection that can be upgraded in a cost-effective manner have been or will be upgraded. However, a number of SSCs require very costly upgrades. In some cases, Duke has chosen to apply the TORMIS methodology and in other cases Duke has selected to implement costly modifications.
For clarification, the first sentence in Enclosure 2, Section 3 of the LAR, is modified as follows:
This LAR incorporatesrevisions to the tornado CLB and includes a number of plant modifications, UFSAR revisions, and an expansion of the use of the tornado missile probabilisticmethodology (TORMIS) in determining which systems, structures, or components require addedphysical protectionfrom tornado-generatedmissiles at the site.
This change clarifies that the use of TORMIS at Oconee is for the evaluation of plant upgrades (for exemption) rather than to imply that TORMIS is used to determine which SSCs are subject to protection requirements.
RAI -13 The ONS UFSAR dated December 31, 2007, contains the following statements: UFSAR Section 3.2.2, "System Quality Group Classification:"
"In addition, there was considerable correspondence between Duke and the NRC in the years post-TMI discussing Oconee's ability to survive tornado generated missiles. Based primarily on PRA justifications, the NRC staff concluded that the secondary side heat removal function complied with the criterion for protection against tornado missiles."
UFSAR Section 10.4.7.3.6, "EFW Response Following a Tornado":
"A probabilistic risk assessment was developed to address the plant's capability to provide secondary decay heat removal via the EFW [emergency feedwater], SSF [Standby shutdown facility], ASW [auxiliary service water], and station ASW Systems, (see Section 10.4.7.3.8) in the event of a tornado. Reference 3 [ONOE- 11376, changes to support multiple unit alignment to the Auxiliary Steam Header] concludes that the Standard Review Plan probabilistic criterion is met based upon the probability of failure of the EFW and station ASW Systems combined with the protection against tornado missiles afforded the SSF ASW System."
As discussed in RAI 1, the NRC staff finds no basis or additional information justifying these statements.
Attachment - Duke Responses to RAI License Amendment Request No. 2006-009 September 2, 2009 Page 13 Provide as basis for the above cited section of the ONS UFSAR.
Duke Response The following wording in UFSAR Section 3.2.2, "...Based primarily on PRA justifications, the NRC staff concluded that the secondary side heat removal function complied with the criterion for protection against tornado missiles," is currently incorrect in that the NRC based their decision (as stated on page 6 of the 1989 SER), "...on its review of the licensee's probabilistic analysis for loss of secondary decay heat removal due to tornado missiles, the staff concludes that the probability of failure of the EFW and ASW systems combined with the protection against tornado missiles afforded the SSFASW system, satisfies the SRP probabilistic criterion, and is therefore, acceptable." However, this section of the UFSAR is being replaced in its entirety and the incorrect wording does not appear in the proposed UFSAR 3.2.2 change.
For UFSAR Section 10.4.7.3.6, the justifying reference should be "Reference 7" rather than "Reference 3." Reference 7 is the NRC SER which summarizes the results [see wording in previous paragraph] of Oconee's response to TM1 Action Plan, NUREG-0737, Item II.E. 1.1, Auxiliary Feedwater System Evaluation, dated July 28, 1989.
Both of these UFSAR items have been entered into Oconee's corrective action program for resolution.
RAI -14 Provide a basis for not including all unprotected SSCs in the TORMIS analysis or revise the TORMIS analysis to include all unprotected SSCs as potential targets.
Duke Response The revised Oconee tornado mitigation strategy primarily utilizes the SSF for SSDHR and RCMU following a loss of all normal and emergency systems which usually provide these functions. The SSF systems can maintain all three units in a safe shutdown condition for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> while damage control measures are completed to restore any unavailable PSW or HPI related equipment needed to cool down the units to approximately 250 'F.
All unprotected SSCs associated with the SSF required to maintain safe shutdown for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after a tornado event are included in the TORMIS evaluation. Other SSCs that do not support the SSF are conservatively assumed to be in a failed state (Prob. = 1) although they provide redundancy (defense-in-depth) which further reduces the actual probability of a release in excess of 10CFR100 limits (see Attachment 4 - Section 5.1). Because these alternate means of achieving safe shutdown are assumed failed, the PSW/HPI systems and other support systems such as Keowee emergency power and I&C power are not included in the TORMIS computer model. In this way, all potentially vulnerable SSCs are considered in the TORMIS evaluation and the overall damage frequency is conservatively estimated.
Attachment - Duke Responses to RAI License Amendment Request No. 2006-009 September 2, 2009 Page 14 Section 5.2 of Attachment 4 of the LAR was intended to document three specific target sets which required special treatment due to special circumstances rather than to imply that they were excluded from the scope of the TORMIS evaluation. These special circumstances include instances where functional redundancy, physical separation, and other qualitative considerations were taken into account, or where limitations of the TORMIS computer code prevented the development of a suitable model to evaluate the targets. Below, additional information and clarifications are provided for each of these target sets.
MS Support Columns The Main Steam support pedestals (3 per unit) were individually modeled in the TORMIS simulation. However, as described in the LAR, the loss of a single column alone will not result in a failure of the required safety function. Therefore, the probability of losing 2 columns at the same time was evaluated and found to be negligible. Because the TORMIS code is limited to evaluating only 2 targets at a time for union and intersection probabilities, the outermost pair of columns for each unit were evaluated for coincident impact. The outer pair of columns was selected because they are closer to vehicle missile storage locations and have the highest potential for vehicle impact. This is referred to in the LAR as a sensitivity case (1 pair per unit). The results of these runs returned a total damage probability of 0.0 for each unit. With a very large sample size and a zero result for the most exposed pair of columns, additional runs were not required to conclude that the overall damage probability for all combinations of 2 of 3 columns being damaged at the same time is also negligible.
CCW Piping The CCW suction source for the SSF was included as part of the overall missile evaluation and was qualitatively evaluated because of code limitations that prevented explicitly modeling it in the missile simulations. Specifically, the CCW piping is in the Turbine Building basement which is below plant grade and the TORMIS code is not capable of evaluating the trajectory of a missile below plant grade (z=0).
The conclusion of the qualitative assessment is that the probability of an SSF failure to mitigate a tornado event due to CCW piping damage is negligible and may be ignored in the simulation model. This conclusion is based on the following considerations:
- 1) The CCW piping is in the turbine building basement and has substantial protection in all but a limited number of locations.
- 2) The system can tolerate significant damage (large break flow) and still maintain adequate reverse gravity flow from the CCW discharge at Lake Keowee to support SSF operation until the SSF submersible pump can be installed.
SSF Trench Vent Pipes The SSF trench vent pipes were included as part of the overall missile evaluation, but were not explicitly modeled in the simulation because a qualitative evaluation concluded the probability of damage was negligible. Additional information is provided below to support this conclusion.
Attachment - Duke Responses to RAI License Amendment Request No. 2006-009 September 2, 2009 Page 15 A further review of the design analysis for the vent was conducted and found that only a single vent pipe (1 of 3) is needed. This analysis is conservative in 2 significant ways. First, it assumes a differential pressure of 3 psid rather than 1.2 psid as required by Regulatory Guide 1.76 Revision 1. Second, it does not account for leakage from around the individual trench cover blocks which is expected to be significant based on observation and the relatively small venting flow area required.
It is also noted that these vents are widely separated; Units 1 and 2 are separated by approximately 200 feet and Units 2 and 3 by approximately 275 feet. Since the primary concern for these targets is vehicle missile impact, the probability of coincident damage to all three vents can be shown to be negligible by comparison to the analysis of the MS Support Columns discussed above. In that case, a pair of much larger columns was shown by analysis to have a negligible probability of coincident damage while separated by only 34 feet.
RAI -15 The NRC staff needs the following information concerning Enclosure 2 of the LAR:
- a. Enclosure 2, Item 3.3.4, second paragraph states the new 100/13.8 kV substation is strategically placed to reduce the probability of concurrent tornado damage to the station switchyard. Provide an explanation of what is meant by strategically placed.
- b. Enclosure 2, Item 3.5 of the LAR states Duke will reconstitute the original wind analysis to ensure the tanks can withstand UFSAR Class 1 wind criteria. As required, vulnerable area so the tanks and flow paths will be physically modified to protect against UFSAR Class I tornado missiles. Provide a schedule for completion of the reconstitution of the original wind analysis. Also, provide a description of all modifications made to protect the borated storage tank and flow paths.
- c. Enclosure 2, Item 3.6 identified one change addressed by this LAR is: eliminating crediting the spent fuel pool, to HPI flow path for reactor coolant make-up. No mark-up of the UFSAR for this proposed change was included in the LAR. Provide a proposed mark-up of the UFSAR for this change.
- d. Enclosure 2, Item 3.8 calls for analyzing a "double column set" and providing modifications. Provide a description of the analysis and the modifications.
- e. Enclosure 2 Item 3.9 discusses protection of the atmospheric dump valves. Provide a description of protective measures for the atmospheric dump valves.
- f. Enclosure 2, item 3.10 calls for improving "...protection of the SSF double doors..."
Provide a description of the protection and basis for the improvements.
Duke Response
- a. The location of the new 100/13.8 kV substation was selected to provide wide separation from existing ONS backup power supplies to prevent coincident tornado damage of all power supplies at the same time. The 230 kV switchyard is supplied from multiple directions including 2 circuits from Jocassee (from the north) while Keowee Hydro is
Attachment - Duke Responses to RAI License Amendment Request No. 2006-009 September 2, 2009 Page 16 located east of ONS, and the new 100/13.8kV substation was placed south of ONS. There is a minimum of approximately 3,000 feet between these power supplies. Using Regulatory Guide 1.76, Rev. 1, Region I data and equation Ib, the resultant wind speed at the perimeter of the 3,000 foot circle would be approximately 64 mph which is within the design capability of Oconee's power supplies.
- b. The wind analysis of the BWST's is currently being developed and is expected to be finished September 2009. Modifications to protect the vulnerable areas of the tanks and flow paths began in July 2009. The new BWST protective structures will be structural steel enclosures surrounding the BWST's. The structures will be approximately 50 ft. x 50 ft. and approximately 12 ft. high. The protective steel structures will be fastened to a substantial reinforced concrete foundation. Excavation of these foundations, the first modification activity, began in July 2009.
- c. The UFSAR marked-up page showing the replacement of the High Pressure Injection (HPI) pump from the Spent Fuel Pool (SFP) flowpath is already contained in the submitted Tornado LAR package (see Attachment 2 [Marked-up pages], page 3.2-4, item "b").
- d. The analysis of the "double column set" has been completed. The analysis concluded that the columns are structurally adequate for Class I tornado. The columns are not required to be reinforced. The analysis indicated, however, that the columns experience some lateral deflection under tornado load. Modifications will be provided to address this deflection by removing rigid links between the column and the MS piping so that the deflection does not adversely affect MS piping.
- e. The atmospheric dump valves (ADV's) will be deterministically protected for Class 1 tornado. At this point, the modification scope for protecting the ADV's has not been developed; therefore details of protective measures are not yet available. The ADV's are planned to be protected as part of the new MSIV installations.
- f. The SSF double door will be upgraded, replaced, or supplemented to meet TORMIS tornado missile criteria. At this point, the modification scope for door improvements has not been developed; therefore details are not available. The door will be improved to perform as it is modeled in the TORMIS analysis.
RAI -16 Provide a description of the measures taken to protect the main steam isolation valves.
Duke Response The new MSIV's will be deterministically protected for Class 1 tornado. At this point, the modification scope for the MSIV's has not been developed; therefore details of protective measures are not yet available.
Enclosure Tables, Drawings, and Diagrams
Enclosure - Tables, Drawings, and Diagrams License Amendment Request No. 2006-009 September 2, 2009 Page 1 RAI-I
- 0-702-Al - One Line Diagram 6900V & 4160V Station Auxiliary System (Rev. 21)
- 0-6700 - One-Line Diagram Main PSW Switchgear (Rev. A)
A).
RAI-2
- 0-6700 One-Line Diagram - Main PSW 125 VDC Power Distribution Center for PSW Building (Rev. A)
RAI-3
0 DC 3.13 - ONS Cable and Wiring Separation Criteria (Rev. 9)
- 0-6700 - One-Line Diagram Main PSW Switchgear (Rev. A) [see RAI-I above]
- K-700 - Keowee Hydro Station - One-Line Diagram (Rev. 31A).
RAI-4
- 0-6700 - One-Line Diagram Main PSW Switchgear (Rev. A) [see RAI-I above].
RAI-5
RAI-7
- 0-6700 - One-Line Diagram Main PSW Switchgear (Rev. A) [see RAI-1 above].
RAI-8
- 0-702 - Unit 1 One-Line Diagram 6900V & 4160V Station Auxiliary System (Rev. 31) 0 0-1702 - Unit 2 One-Line Diagram 6900V & 4160V Station Auxiliary System (Rev. 21)
- 0-2702 - Unit 3 One-Line Diagram 6900V & 4160V Station Auxiliary System (Rev. 23)
- 0-6700 - One-Line Diagram Main PSW Switchgear (Rev. A) [see RAI-1 above]
Enclosure - Tables, Drawings, and Diagrams License Amendment Request No. 2006-009 September 2, 2009 Page 2
- O-703-D - Unit 1 One-Line Diagram Station Auxiliary Ckts 600V (Rev. 56A)
- 0-703-E - Unit 1 One-Line Diagram Station Auxiliary Ckts 600V (Rev. 63A)
- 0-1703-C - Unit 2 One-Line Diagram Station Auxiliary Ckts 600V (Rev. 27A)
- O-1703-D - Unit 2 One-Line Diagram Station Auxiliary Ckts 600V (Rev. 48A)
- 0-2703-C - Unit 3 One-Line Diagram Station Auxiliary Ckts 600V (Rev. 40B)
- O-2703-D - Unit 3 One-Line Diagram Station Auxiliary Ckts 600V (Rev. 55B).
RAI-9
- 0-6700 -,One-Line Diagram Main PSW Switchgear (Rev. A) [see RAI-1 above]
- K-700 - Keowee Hydro Station - One-Line Diagram (Rev. 31A) [see RAI-3 above].
RAI- 10
- Cable Routing Diagram (Schematic) - Elevation Looking East
- Cable Routing Diagram (Schematic) - U1 Auxiliary Building Elevation 796'-6"
- Cable Routing Diagram (Schematic) - U2 Auxiliary Building Elevation 796'-6"
- Cable Routing Diagram (Schematic) - U3 Auxiliary Building Elevation 796'-6"
- Cable Routing Diagram (Schematic) - Plan Elevation 783'-9" (Columns 81-84)
- Cable Routing Diagram (Schematic) - Plan Elevation 783'-9" (Columns 84-87)
- OD500940 - KHU Cable Drawing [as revised 4/21/2009].
MRv -3 VERIFY HARD COPY AGAINST WEB SITE IMMEDIATELY PRIOR TO EACH USE PDuke oPower. Power Generation A Duke Energy Company Electrical Engineering Discipline Design Manual DC-3.13. Oconee Nuclear Station Cable and Wiring Separation Criteria Revision No.: 9 Below is a list of pages valid for this Engineering Criteria. An asterisk (*) indicates those pages affected by this revision.
Pa1es Revision 2* 9 3* 9 4* 9 5* 9 9
6 9 7 9 8* 9 9* 9 10 9 11* 9 12* 9 13* 9 14* 9 Revision
Description:
Revision 9 adds a new cable color designation (Red) for the Protected Service Water Project. Revised per PIP 0-07-4683, CA 7 to incorporate changes based on SQUG criteria for the cable support system. Revised 8.4.3 to include method for applying refrasil to cable.
Implementation Date: 12/01/08 Originated By: Gary D. Chronister Date: 9/09/08 Checked By: W. Thomas / J. T. Edgar Date: 9/09/08 Approved By: R. L. Murphy Date: 9/09/08 NSD EDP Coord: D. T. Griffin Date: 1/21/09 VERIFY HARD COPY AGAINST WEB SITE IMMEDIATELY PRIOR TO EACH USE
DC-3.13. Oconee Nuclear Station Cable and Wiring Separation Criteria Revision No: 9 Page ii Date: 1/21/09 Table of Contents 1.0 TITLE ................................................................................................................................................................... 1 2.0 PURPO SE ............................................................................................................................................................. 1 3.0 SCOPE .................................................................................................................................................................. 1 4.0 DEFIN ITION S ..................................................................................................................................................... 1 5.0 CA BLIN G SY STEM G EN ERA L D ESIGN ....................................... :............................................................ 3 6.0 CA BLIN G SY STEM CRITER IA ........................................................................................................................ 7 7.0 MAIN CONTROL BOARD INTERNAL WIRING CRITERIA ................................................................. 10 8.0 WIRING SEPARATION REQUIREMENTS FOR ELECTRICAL ENCLOSURES OR CABINETS ............. 10 9.0 IM PLEMEN TA TION ......................................................................................................................................... 13 10.0 REFEREN CES ................................................................................................................................................... 13
Revision No: 9 DC-3.13. Oconee Nuclear Station Cable and Wiring Separation Criteria Date: 1/21/09 Page 1 of 13 1.0 Title Cable and Wiring Separation Criteria 2.0 Purpose The purpose of this criteria is to provide standardization for the responsible Engineering group's routing of cables, field installation of cabling systems (both the cable itself as well as the support system), and serve as a basis for QA inspection of completed installation of cabling and cable support systems, installed after the effective date of this criteria. It also includes the design, installation, and QA inspection of wiring inside the Main Control Boards after the effective date of Revision 1 (3/1/90), and the design, installation, and QA inspection of wiring inside any electrical enclosure after the effective date of Revision 3 (04/01/99).
3.0 Scope All QA I cable installed at Oconee after 7/15/87, and Keowee after 3/15/95 shall meet as a minimum, the criteria discussed below.
All QA 1, Main Control Board wiring installed at Oconee after 03/01/90 shall meet, as a minimum, the criteria in Section 7.0. All Keowee Control Board wiring installed after 3/15/95 shall meet, as a minimum, the criteria in Section 7.0.
All wiring installed after 4/1/99 at Oconee and Keowee, inside electrical enclosures, other than the Main Control Boards, shall meet as a minimum, the criteria in Section 8.
Cabling or wiring installed prior to these dates is not subject to this criterion and its installation criteria will continue to be the UFSAR as a basis for acceptability. Any new safety related cabling, or wiring which cannot fully meet these criteria in design or installation shall be fully documented by the responsible Engineering group in correspondence File OS-224 as to the reason why the criteria cannot be met, and justification of the adequacy of the proposed design or installation. All cabling and wiring, regardless of installation date, shall comply with UFSAR commitments. Cabling associated with the SSF shall comply with criteria DC-15.01 in addition to the requirements in this document.
Note: It is fully intended that almost all cabling and wiring will meet this criteriaand that very few cases will require exception documentation by the responsible Engineering group performing the cable and/or wiring installation.
4.0 Definitions 4.1 Barrier Physical material installed on, around or between cables and/or trays to provide isolation from one cable to another. Examples are conduit, metal tray covers, 22 Gauge or thicker sheet metal, 1/8" glastic, 1/8" epoxy glass sheeting, 1/8" metal plate, Refrasil, and mineral insulated cable.
Note: Cable armor although providing substantial protection is NOT considered a barrier for the purpose of Sections 5 and 6. This definition of a barrieris applicable only to cable and the cable support system. For barrierdefinition related to wiring refer to Section 8.
4.2 Cable One or more conductors encased by an overall armor (braided or interlocked). Non-armored cables are not to be installed within the regular cable support system.
DC-3.13. Oconee Nuclear Station Cable and Wiring Separation Criteria Revision No: 9 Page 2 of 13 Date: 1/21/09 4.3 Cable Tray Rectangular, metallic, cable support device with solid sides and open bottom with supporting cross members.
4.4 Cable Tray Fittings Metallic hardware such as splice plates, tees, turns, elbows, "X" fittings, etc. used with rectangular tray sections.
4.5 Cable Terminator Metallic hardware used at equipment, junction boxes, control panels, etc. to terminate the cable-armor and provide strain relief attachment to the equipment.
4.6 Cable Trench Concrete cable raceway under floors and in outside yard areas to route and protect cable from physical damage. A trench will normally have removable covers. A trench may or may not have cable support structures (tray, electray, conduit or Unistrut) mounted within.
4.7 Cable Trough Typically an enclosed channel of formed solid metal with a removable or hinged cover and open at the ends. Troughs are used to provide cable separation via the metal walls for cable transition past cables of another color. Troughs are typically used to change elevation or elevation and horizontal direction from one point to another while providing separation from adjacent cable trays. Troughs are usually mounted on the sides of cable tray and/or cable tray supports.
4.8 Conduit Metallic pipe or tubing in which cable can be inserted for support and protection.
4.9 Conduit Fittings Metallic hardware such as couplings, elbows, condulets, pull boxes, etc. used with conduit sections.
4.10 Electray Rectangular metallic cable support device with short solid sides and semi-open bottom. Electray is of one-piece construction and is usually 6" or smaller in width and made from either mechanically formed aluminum or galvanized steel.
4.11 Mutually Redundant A piece of equipment or a system that duplicates the essential function of another piece of equipment or system to the extent that either may perform the required function regardless of the state of operation or failure of the other (Ref. 10.7). At Oconee, this is typically equipment or systems in which there are a minimum of two channels or trains performing the same safety function and which are totally independent of each other. Systems such as Reactor Protection (RPS) have four completely independent channels. Systems such as Emergency Feedwater (EFW) have two completely independent trains. PSW has only one train however the PSW Main pump circuits, Booster pump circuits and associated valve circuits are mutually redundant to the SSF ASW pump and valve circuits.
Note: Redundancy can be accomplished by the use of identical channels or trains of identical equipment, equipment diversity (AC vs. DC), or functional diversity. At Keowee, this term is applied on a Unit basis.
For example, mutual redundancy is two cables performing the same function, one for Unit ] and the other
Revision No: 9 DC-3.13. Oconee Nuclear Station Cable and Wiring Separation Criteria Date: 1/21/09 Page 3 of 13 for Unit 2. Likewise, a piece of equipment or a component that provides a QA] function on Unit 1 is mutually redundantto its Unit 2 counterpart.
4.12 OpeningslShafts/Sleeves Penetrations through wall, floors, and ceilings, which allow the cabling to pass through. Sleeves are openings through a floor or wall where cables pass. The sleeve is typically lined with a length of steel piping if round or other steel shapes if square. Round openings are typically used in floor penetrations while square is the more common shape for wall penetrations. Sleeves typically contain a single color of cable or a single color of cable plus black cable. In certain circumstances, a second color of cable will be installed in the sleeve. Square penetrations are installed in walls or floors to accommodate cable tray(s) instead of individual cables. Multiple colors as well as black cables may be present in these openings.
(See Section 6.12).
4.13 Transition Area The unsupported section of cable in transition from the cable tray, electray, trough or conduit system.
Transition areas may also be used to refer to sections of cable tray, electray, where cable(s) enter and/or exit the tray. This also includes any cable(s) outside the cable tray support system.
5.0 Cabling System General Design 5.1 Cable System Color Coding 5.1.1 Oconee The cable system separation criteria are based upon the relationship of different cabling use or functions.
Cables furnished for installation at Oconee are color coded to aid in identifying their use and/or channel association.
The color-coding of cable is accomplished through the use of paints, inks,,tapes, or factory supplied colored jacketing. The color-coding shall be applied over the length of the cable to ensure that the visual observation of the installation maintains these separation requirements. The cable shall be color coded in accordance with OSS-0218.00-00-0016, Section 16.0 prior to the installation. Following the installation, the designated cable color shall be readily apparent or the cable shall be repainted or taped at the ends and transition areas in accordance with OSS-0218.00-00-0016. Black jacketing on cable is the existing industry standard and is not defined or considered as a "color" throughout this criterion. Unjacketed cable types specified as black do not require paint or tape to identify the cable color. Bare armor cable will be considered as black unless otherwise color-coded. The use of tape for color-coding cable inside containment is NOT permitted.
The color code is as follows:
Black: Non Safety related applications Green: 4kV Main Feeder Bus #1 (Unit I Only)
Brown: 4kV Main Feeder Bus #2 (Unit 1 Only)
Gray: Switchgear ITC, 2TC, 3TC Load Centers IX8, 2X8, 3X8 Motor Control Centers IXS 1, 2XS 1, 3XS I ESG Channels 1, 3, 5, 7 (Odd)
DC Panelboards I DIA, 2DIA, 3DIA
DC-3.13. Oconee Nuclear Station Cable and Wiring Separation Criteria Revision No: 9 Page 4 of 13 Date: 1/21/09 Vital Power Panelboards IKVIA, 2KVIA, 3KVIA RPS Channel A Standby Shutdown Facility 120/208VAC Power Panelboards 1SKJ, 2SKJ, 3SKJ 120/240VAC Power Panelboards ISKM, 2SKM, 3 SKM Yellow: Switchgear lTD, 2TD, 3TD Load Centers 1X9, 2X9, 3X9 Motor Control Centers IXS2, 2XS2, 3XS2 ESG Channels 2, 4, 6, 8 (Even)
DC Panelboards I DIB, 2DIB, 3DIB Vital Power Panelboards IKVIB, 2KVIB, 3KVIB RPS Channel B 120/208VAC Power Panelboards ISKK, 2SKK, 3SKK 120/240VAC Power Panelboards ISKN, 2SKN, 3SKN Blue: Switchgear ITE, 2TE, 3TE Motor Control Centers 1XS3, 2XS3, 3XS3 DC Panelboards I DIC, 2DIC, 3)DIC Vital Power Panelboards IKVIC, 2KVIC, 3KVIC ESG Channel Even-Odd Transformer 1XlO, 2X10, 3XI0 RPS Channel C 120/208VAC Power Panelboards ISKL, 2SKL, 3SKL 120/240VAC Power Panelboards 1SKP, 2SKP, 3SKP Orange: DC Panelboards 1DID, 2DID, 3DID Vital Power Panelboards I KVID, 2KVID, 3KVID RPS Channel D Red: Protected Service Water System Switchgear B6T, B7T Load center PX 13 MCC XPSW, IXPSW, 2XPSW, 3XPSW Power Panelboards IKPSW, 2KPSW, 3KPSW DC Pnlbds, PSW1DC, IPSW2DC, 2PSW2DC, 3PSW2DC
Revision No: 9 DC-3.13. Oconee Nuclear Station Cable and Wiring Separation Criteria Date: 1/21/09 Page5 of 13 5.1.2 Keowee Cables furnished for installation at Keowee will be color coded to aid in identifying their unit assignment and QA classification. The color code will be as follows:
Gray: Unit 1, QA1 Cabling, Safety Channel A Yellow: Unit 2, QA1 Cabling, Safety Channel B Black: Units I & 2, Non-QAI Cabling Red: Units I & 2, Protected Service Water Cabling Note: Switchyard cable color coding varies from these inplant color codes. To avoid confusion, switchyard colors are not discussed in this criterion and are provided on Electrical Elementary drawing OEE-14-1A.
5.2 Cable Separation Methodology 5.2.1 Oconee Separation of the colored cabling may be accomplished by two basic methods - distance or barriers.
Distance is measurable free air separation between cables, whereas barriers are a physical device provided when the minimum free air measurement cannot be met. These two separation methods are based upon the use of armor protected cable, i.e., aluminum sheath, bronze tape, served wire and braided or interlocked armor.
5.2.2 Keowee Separation of the colored cabling will be accomplished by routing mutually redundant cables in separate cable trays. Mutual redundant cables will not come in contact with each other. If required, a barrier will be installed between cables to prevent contact.
5.3 Cable Support Systems 5.3.1 Oconee All safety related cable at Oconee is installed within a cable support system. The main cable support system is designed to meet a minimum of five (5) inches free air distance between different colored cables for adequate cable separation. In the event a cable support system installation results in tray installed with less than 5 inches free air distance between a full lower tray and the bottom of an upper tray (hence, cables less than 5" from bottom of tray above), .a 1/8" fire retardant barrier (or other equivalent barrier material as described in Section 4.1) shall be installed on the bottom of the tray above.
5.3.2 Keowee The Keowee cable support system has power and control cables routed within the same tray without the use of a barrier. Installations of power cabling after 3/15/95 will meet Section 6.2 of this document.
Control cables may be installed within the existing cable tray system, which contains both power and control. Mutual redundancy separation requirements will be maintained.
Exception: Due to the existing overfill condition in the Unit 1 Cable Room, the five (5) inch free air space rule has been modified to a three (3) inch free air space rule. In the event that the top cable in the lower tray is less than three (3) inches from the bottom cable in the tray above, a 1/8" fire retardant barriershall be installed between the trays. The barriershall be attachedto the bottom of the upper tray
DC-3.13. Oconee Nuclear Station Cable and Wiring Separation Criteria Revision No: 9 Page 6 of 13 Date: 1/21/09 and fitted around cables, which may pass through the barrierwhen in transition. Cables in this transition shall not touch the cables from the adjacenttray.
5.3.3 Cables will be continuously supported by the cable support system. Individual cables may be bundled together in the cable support system using tie wraps. Power cables may be bundled provided they meet the guidance of Section 6.2 regarding cable ampacity derating. When 6 inch or smaller electray is on its side or inverted, stainless steel tie wraps shall be used as described below to retain the cable bundles in the cable support system. When ladder type cable tray (6" and larger) is used on its side for cable routing, the cables shall be tie wrapped to the ladder support rungs. Cables may be bundled and then tie wrapped to the ladder rungs.
Because electray is not fabricated with individual bottom rungs, stainless steel ties shall be used every 2 feet to provide cable retention to the electray. 3/16" nominal SS ties shall be used on 4" and smaller electray, while 5/16" nominal SS ties shall be used on 6" electray. 5/16" SS ties may be used on 6" cable tray to retain the cabling within the tray in conjunction with the individual cable or cable bundle tie down to the rungs. The use of stainless steel tiewraps and cable bundling has been evaluated and documented in File OS-224 for the purpose of retaining cabling in the cable support system when it is on its side or inverted.
As of 12/16/97, only stainless steel tie wraps shall be used inside the Oconee reactor buildings for all new cable installations. This includes securing individual cables in cable tray as well as securing bundled cable in electray. Nylon tie wraps are no longer permitted to be used to secure cables in cable tray or electray in the reactor building.
5.3.4 Cables which enter or leave the tray system enroute to a device must be supported. Safety cables within this application shall be required to maintain a limited separation criteria. Cables of different safety colors may be within five (5) inches of each other when entering or accessing a common enclosure.
Colored cables shall be precluded from making contact with each other. Cable terminators on the common enclosure may touch each other. Cables the same color and associated black cables which are classified control or instrumentation may be bundled together and held with tie-wraps for neatness and efficiency. Power cables shall not be bundled together unless meeting the ampacity derating criteria of Section 6.2 and specific approval is provided by the responsible Engineering group and documented in correspondence to file OS-224, the Design Inputs Calculation for a Nuclear Station Modification, or Documentation of Design Inputs for Minor Modifications (Ref. 10.8). Support intervals of cables shall be determined by the following table:
Cable Support Intervals Cable Diameter Inches Maximum Unsupported Distance Single Cable or bundle Less than '/2 24 inches 1/2/2 through 1 42 inches Greater than I through 2 60 inches Greater than 2 through 3 78 inches Greater than 3 96 inches
Revision No: 9 DC-3.13. Oconee Nuclear Station Cable and Wiring Separation Criteria Date: 1/21/09 Page 7 of 13 6.0 Cabling System Criteria 6.1 Power and Control Cables as defined in DC-3.02 shall be routed in cable support systems designated for this 'Use to prevent high energy power cables from adversely affecting instrumentation and/or control functions. In the event the responsible Engineering group determines that both power and control cable must run in the same tray or opening, a barrier will be provided in the cable routing design to provide separation and shielding.
The metal barriers, or barrier strips, should be installed using factory supplied mounting hardware. In the event that this hardware is not used, then #10x16x3/4" Cross Recessed (Phillips Head) Panhead, Zinc plated, Carbon Steel or Stainless Steel self drilling & tapping screws can be used. Screws shall be installed into the cable tray ladder rung/cross brace. One screw shall be installed at each end of the barrier section into the rung and every other rung in between. Screws may end up installed on adjacent rungs. QA1, QA4 and Non-QA1 cable tray installations may use Non-QA1 screws. QAI screws can be used if available. In addition, when more than one barrier is installed in a continuous run, factory supplied splice clips ("S" Clips) should be used to connect the continuous run of barriers end to end. If "S" clips are not used, then an alternate method using a 1/2" overlap on connecting lengths of barriers is acceptable. When using the 1/2" overlap joint method, plastic/rubber trim material may be used to provide additional retention at the top of the lapped section to prevent the joint from separating. If plastic/rubber trim is used, then it must overlap the lapped section by 3" on each side. Adhesive may be used to provide additional bonding of the trim to the barrier. Either method is acceptable for QA1, QA4 and Non-QAI installations. The "S" clips are available both Non-QA and QAI. Installation of the clips or trim is considered Non-QA. "S" Clips or the overlapping joint methodology provide joint support to minimize the potential of cable jacket scuffing due to barrier misalignment during cable pulling.
When transitioning elevations, making bends or radii, or anywhere there is a cable tray fitting, it is acceptable to overlap greater than 1/2" at the barrier joints. Also, the use of fasteners in adjacent cable tray rungs is acceptable. "Pop" rivets should be used in the vertical section of the barrier to aid in the fabrication of the transition barriers when they have been cut to make bends.
6.2 A minimum spacing of one fourth the diameter of the larger adjacent cable may be provided, and is preferred, between individual power cables. Power cable at Oconee has historically been installed in this manner. This spacing is an average distance and may vary slightly between tiedown points due to training and transition areas. If cables touch, the contact should be limited to less than two feet or the cable will be required to meet the following requirements for cable spacing not maintained.
Cable Spacing not maintained (Cable installations after 12/16/97):
When cable spacing cannot be maintained, or it is desired to install cable without any spacing, the installation shall comply with the following requirements which themselves are based on guidance contained in ICEA P46-246 (Ref. 10.10) and/or the National Electric Code (Ref. 10.9). Power cable installed at Oconee is initially derated by 30% (Ref. 10.3) and sized to accommodate voltage drop considerations (Ref. 10.11). This sets the installed ampacity loading factor of any given power cable no higher than 70% of rated ampacity per References 10.9 and 10.10. In many cases, actual ampacity usage may be even lower (i.e. 40% of rating).
Power cable shall be installed in a single layer in ladder type cable tray or ventilated electray and the sum of the cable diameters shall not exceed the cable tray or electray usable width. Power cable may be stacked in cable tray or in electray provided the ampacity ratings meet the requirements of Table VIII of Reference 10.10.
DC-3.13. Oconee Nuclear Station Cable and Wiring Separation Criteria Revision No: 9 Page 8 of 13 Date: 1/21/09 When power cable is installed without the 1/4 diameter of the larger adjacent cable spacing or is stacked, the installation must be evaluated for ampacity loading. This must be documented in correspondence file OS-224, or in the Design Input Calculation for Nuclear Station Modifications, or in Documentation of Design Inputs for Minor Modifications (Ref. 10.8). Power classified cables may be installed together within the same tray without regard to voltage.
6.3 Control and instrumentation cables as defined in DC-3.02 may be installed within the same cable tray designated as control. Cable tray fill is based on a full cable tray equivalent and loading on the cable tray support system. Due to the installation and training of cable, voids may exist within a tray cross section.
This has led to the appearance of many cable trays as being overfilled (cables exceeding the top level of the side rails).
This situation primarily occurs in transition areas where cables enter or exit the tray system, or where offsets are present such as elbows or tees. This may also occur in straight runs where cables were not properly trained through the tray.
Cable trays that contain cables exceeding the top of the side rails on the straight run of the tray are subject to evaluation prior to installation of any additional cables. An evaluation can be performed on a visual basis, considering the physical characteristics of the cable tray and the installation of the cables.
DBD OSS-0254.00-00-4019 (Design Basis Specification for the Cable Tray Supports) was issued as revision 3 in March, 2004. This revision incorporated the SQUG analysis and reflected its use as the design basis for the cable support system at Oconee and Keowee.
The loading for the tray system is established at a value of 35 lbs. per sq. ft. for all cable trays. The 35 lb per sq ft loading is reflective of previous weights established for seismic qualification. Tray loading values are considered to be trays filled to 100% capacity.
The SQUG review of cable tray for the Reactor Buildings analyzed the supports based on an as built configuration and does not qualify the tray to full loading. As cables are added to the tray system inside containment a SQUG review is required for all cables routed inside containment so the calculation can be revised for the added weight.
Cable tray overfill conditions were recognized to exist and worst cases were analyzed during the initial SQUG review. No operability issues with the overloaded trays were identified at that point in time.
(OSS-0254.00-00-4019, 2.3.4, Cable Tray Overfill)
Cables installed in short side rail electray may be bundled together and held in the tray by stainless steel tiewraps and exceed the side rail depth. The electray must provide continuous support for the cables as outlined in section 5.3.3.
6.4 Trenches may simultaneously contain power, control and instrumentation cables. If cable tray, electray, or conduit is not provided for cable support, power cables within a trench shall be racked on the side of the trench or on unistrut cross members per Section 6.2 of this criteria. Control and instrumentation cables shall be laid in the bottom of the trench. Mutually redundant safety cables shall be located on opposite sides of the trench.
Exception: The trenches serving the blockhouse from the Turbine Building do not have provisions for racking of power cables. The responsible Engineering group will provide specific instructions for the addition of anv safety cables in this area
Revision No: 9 DC-3.13. Oconee Nuclear Station Cable and Wiring Separation Criteria Date: 1/21/09 Page 9 of 13 6.5 Black and red cables may be routed within a colored tray but then may not be routed with a different safety color anywhere within its remaining length. Red cables are not considered mutually redundant to any other cable except as identified in Section 4.11. Red cables are not to be routed in the West Penetration Rooms or the Cask Decontamination Rooms. The alternate feeder from the PSW to the SSF may be routed without any color separation requirements from SSF cables.
6.6 Colored cables may be installed within a black designated tray which has been seismically qualified when a barrier has been installed to separate the colored cable from the black cabling.
6.7 Colored cables within the tray system transition areas (i.e., tees, elbows, etc.) shall maintain five (5) inches of free air space between itself and any other colored cables. Unit I Cable Room shall maintain three (3) inches. Barriers shall be installed any time the free air distance requirement cannot be met.
6.8 Mutually redundant safety related cables shall be run in separate trays and shall maintain the separation requirement of Section 6.7.
6.9 Redundant safety channel cables will be routed in the appropriately designated separate colored trays. An exception to this requirement can be specified where necessary by the responsible Engineering group to allow the installation of different colored cables within the same tray. This exception may or may not require the use of barriers. Engineering must document this exception in correspondence file OS-224 and provide specific design requirements for proper installation on the individual cable routing/installation sheets.
6.10 Reactor Building cabling for nuclear instrumentation, ES instrumentation and RPS instrumentation shall be installed within their respective channel colored instrumentation trays. These four colored trays are routed in separate directions to maintain at a minimum seven (7) feet of distance between redundant channels. Cables leaving the tray in transition to a device must maintain this seven (7) foot separation. In addition, these four tray may have low signal level (typically < 50 Volts and < 100 milliamps) safety related post accident monitoring instrumentation cables of the appropriate color installed within these trays. Barriers may be installed within these instrumentation trays to allow installation of safety related control cables of the same color.
6.11 In the Penetration and Cable Rooms, cables from each protective channel are routed in trays separate from those carrying cables from any other protective channel. Included in these trays are instrumentation cables from the Reactor Building, control and interconnecting cables associated with that protective channel, andnon-protective instrumentation and control cables.
6.12 Cables in transition through floor or wall sleeve type openings shall meet the same separation criteria as the tray system. Barriers shall be installed within the sleeve openings to separate a colored cable from black cables. Only one color of cable should be in a given opening with black cable. The responsible
DC-3.13. Oconee Nuclear Station Cable and Wiring Separation Criteria Revision No: 9 Page 10 of 13 Date: 1/21/09 Engineering group may determine that a second color, in addition to the one already installed or planned for installation with black cabling, must also be run through the sleeve opening. In this event, the second colored cable will be installed within rigid conduit and located, if applicable, with the black cabling within the opening. The conduit shall extend in length and/or location within the sleeve until the distance criteria can be met. Engineering must document this exception in correspondence file OS-224. Mutually redundant safety related cables shall not pass through the same opening. This requirement does not apply to multiple cable tray installations, which pass through wall or floor openings.
6.13 Safety related cabling installed at the Oconee Nuclear Station or the Keowee Hydro Station shall meet the separation requirements defined within this criteria. The responsible Engineering group will analyze and document to correspondence file OS-224 any unique or special cable routing or separation requirement which cannot be installed per this specification prior to implementation.
7.0 Main Control Board Internal Wiring Criteria Wiring, control components (switches, pushbuttons, etc), indicators, recorders, etc. shall be installed so as to maximize the physical separation distance between mutually redundant safety related wiring, devices and components. In no case shall mutually redundant safety related wiring or devices be in physical contact.
Oconee: Wiring shall be marked at 18-inch (maximum) intervals using flame retardant colored plastic tags for the four safety channels. These tags shall be approximately 1 1/2 X 2 1/8 inches in size and have permanently embossed or hot stamped on them the wording "Safety Channel A (B, C, or D)." Color coding for these tags shall be Gray, Yellow, Blue, and Orange for Channels A, B, C, and D respectively.
The Protected Service Water System safety wiring shall use "Red" colored tags. Further explanation of color codes and channels can be found in Section5.l.
Keowee: Wiring shall be marked at 18 inch (maximum) intervals using flame retardant colored plastic tags for the appropriate safety channel. These tags shall be approximately 1 1/2 X 2 1/8 inches in size and have permanently embossed or hot stamped on them the wording "Safety Channel A (B)". Color coding for these tags shall be Gray for Unit 1, Safety Channel A, and Yellow for Unit 2, Safety Channel B. The Protected Service Water System safety wiring shall use "Red" colored tags. Further explanation of color codes and channels can be found in Section 5.1.
Note: The Main Control Boards are defined as the Unit Boards, Vertical Boards, Auxiliary Benchboards, and Electrical Boards for Oconee, and the Control Boards and Electrical Boards for Keowee. Barrier use as described below is permissible in the Main Control Boards at Oconee and Keowee. Justification and adequacy must be addressedin file OS-224.
8.0 Wiring Separation Requirements for Electrical Enclosures or Cabinets 8.1 Scope The requirements of this section apply to any electrical enclosure. Main Control Boards separation is covered in Section 7.
8.2 Definitions
( Applicable to Sections 7 & 8 only) 8.2.1 Apparatus An integrated group of materials or devices used for a particular purpose.
Revision No: 9 DC-3.13. Oconee Nuclear Station Cable and Wiring Separation Criteria Date: 1/21/09 Page 11 of 13 8.2.2 Barrier EMT conduit, rigid conduit, 1/16 inch thick metal plate, 1/8 inch thick glastic, flexible conduit, interlocked armor cable, stainless steel braided armor cable, Refrasil UT-96-2 tape, 0.05 inches thick, 2 inches wide with adhesive backing. "Panduit", or other wire training devices, while used to maintain separation, are not to be considered as barriers unless 1/8 inch thick and unslotted.
8.2.3 Device An item intended to carry, or help carry, but not utilize electrical energy. Units such as switches, circuit breakers, fuse holders, receptacles, etc. that distribute or control, but do not consume electricity are termed devices.
8.2.4 Enclosure The case or housing of an apparatus surrounding an installation to prevent personnel from accidentally contacting energized parts, or to protect the equipment from physical damage.
8.2.5 Wiring Insulated wire comprised of a slender rod or filament of drawn metal surrounded by a substance permanently offering a high resistance to the passage of energy through the substance. May also be known as hookup wire, SIS wire, or white wire.
8.2.6 Cable One or more conductors with or without fill material surrounded by an overall armor (typically braided or interlocked).
8.3 Criteria
8.3.1 Wiring and control devices are to be installed so as to maximize the physical separation distance between mutually redundant safety related wiring. In no case, shall mutually redundant safety related wiring or devices be in physical contact. When separation cannot be maintained a barrier must be installed.
8.3.2 All QA 1 designated wiring is to be physically identified in accordance with Section 7. If the wiring is enclosed by use of a barrier, the tag shall be attached to the barrier's exterior to identify the channel contained inside.
8.3.3 Non essential and PSW System wiring may be run in wire ways or bundled with QA I wiring. The wires may only be run with one color without the use of a barrier.
8.3.4 If wiring is not completely enclosed by a barrier, the wiring may not protrude above the top of the barrier.
8.3.5 No separation distance is required between adjacent wiring and a barrier.
8.3.6 Where more than one mutually redundant channel or train is connected to one device, the wiring shall be separated through the device. ( separate terminal blocks/links, control switch contacts, relay decks, etc.)
DC-3.13. Oconee Nuclear Station Cable and Wiring Separation Criteria Revision No: 9 Page 12 of 13 Date: 1/21/09 8.3.7 Duke Power modifications to vendor scope panels should conform to the separation criteria specified herein where practicable. If the separation criteria is not practicable, the original vendor separation methods should be observed by use of the vendor established wire- ways, wire tracks, and wire troughs.
8.3.8 Any exception to these criteria shall be documented in a memo to file OS-224, justifying the installation and its acceptability. This is also applicable to 8.3.7 above, if separation is not maintained.
8.4 Barrier Installation 8.4.1 Where metallic barriers are used between redundant devices the barrier shall be tied to station ground with a minimum #12 conductor.
8.4.2 EMT conduit, rigid conduit, glastic, flexible conduit are to be installed based on enclosure design and seismic considerations.
8.4.3 Refrasil UT-96-2 tape, 0.05 inches thick, 2 inches wide with adhesive backing may be used if applied in the following manner.
8.4.3.1 To achieve wireway to wiring separation, install material on wiring if practical. If not practical, install on wire way.
8.4.3.2 To achieve wireway to wireway separation, install material on either wireway.
8.4.3.3 To achieve cable to cable separation.
8.4.4 Wrapping Method: (Refrasil Tape) 8.4.4.1 For wireways or wire bundles, the material shall be wrapped in two layers with a minimum of 1/4 inch overlap between adjacent wraps. The second layer is to be wrapped using the same method but in a direction perpendicular to the first layer. This will insure a double thickness with no gaps. The material is to be secured with standard nylon ty- raps, spaced at a maximum of twelve-inch intervals or at each end of the wrap (whichever distance is smaller).
8.4.4.2 Where continuous wrapping is impossible (e.g., where wire ways are welded to a surface along the length of the wire way), the following method is to be used. The material shall be attached in two layers, in strips, using adhesive backing with 1/4 inch minimum overlap between adjacent strips. The second layer is to be installed in the same manner but in a direction perpendicular to the first layer.
Revision No: 9 DC-3.13. Oconee Nuclear Station Cable and Wiring Separation Criteria Date: 1/21/09 Page 13 of 13 8.4.4.3 If space between wireways, and/or wiring is extremely tight the material may be wrapped lengthwise in two layers and overlapped by 1/4 inch.
9.0 Implementation 9.1 The implementation date of this installation specification revision is shown on page CS-1. Installations made prior to this date are considered acceptable provided the installations were made in accordance with previous revisions. (See also Section 3.0 Scope.)
10.0 References 10.1 Duke Power Company, Design Criteria DC-3.02, Cabling Classifications 10.2 Duke Power Company, Design Criteria DC-3.06, Conduit Systems for Power Plants 10.3 Duke Power Company, Design Criteria DC-3.12, Cable Ampacity Design Criteria 10.4 Duke Power Company, Design Criteria DC-3.13, Oconee Nuclear Station Cable and Control Board Separation Criteria 10.5 Duke Power Company, Design Criteria DC-3.14, Cable Classification and Separation for Non-Interlocked Armored Cable 10.6 Specification OSS-0218.00-00-0025, Specification for the Installation of Field Run Cable Support Systems 10.7 IEEE Std 603-1980, IEEE Standard Criteria for Safety Systems for Nuclear Power Generating Stations 10.8 Nuclear System Directive - NSD301, Nuclear Station Modifications 10.9 National Electrical Code, 1996 10.10 Insulated Cable Engineers Association (ICEA), Publication IEEE S-135, ICEA P-46-426 10.11 Duke Power Company, Calculation Guide, CA-2.01, Calculations for Voltage Drop and Voltage Dip Determination 10.12 Memo to File: OS-224, Electrical Cable Separation for Keowee Hydro Station, dated March 15, 95.