ML20099D830
| ML20099D830 | |
| Person / Time | |
|---|---|
| Site: | 05200002 |
| Issue date: | 07/25/1992 |
| From: | ABB COMBUSTION ENGINEERING NUCLEAR FUEL (FORMERLY, ASEA BROWN BOVERI, INC. |
| To: | |
| Shared Package | |
| ML20099D825 | List: |
| References | |
| NUDOCS 9208070100 | |
| Download: ML20099D830 (299) | |
Text
r SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS-DESIGN GUIDE Prepared by:
ABB COMBUSTION ENGINEERING NUCLEAR POWER WINDSOR, CT-
+
4 DUKE ENGINEERING & SERVICES, INC.
CHARLOTTE, NC i
DRAFT July 25, 1992 9208070100 920731 PDR ADOCK 05200002 A PDR
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE TABLE-OF CONTENTS-Section Title Pace 1.0 PURPOSE 1-1 2.0 SCOPE 2-1.
3.0 INTRODUCTION
3-) ,
4.0 SYSTEM DESIGN CONSIDERATIONS 4-1 4.1 GENERAL 4-1 4.1.1 SYSTEM REQUIREMENTS 4-1 4.1.1.1 System Function 4-1 4.1.1.1.1 Functions 4.1.1.1.2 Constraints 4.1.1.2 Performance Requirements 4-1 4.1.1.2.1 Safety Classification 4.1.1.2.2 Seismic Classification 4.1.1.2.3 Redundancy / Diversity Requirements 4.1.1.2.4 Capacity Requirements 4.1.1.2.5 Failure Considerations 4.1.1.2.6 Design Basis Events and Transient Considerations 4.1.1.3 Ooerational Reauirements 3 4.1.1.3.1 Power or Cooling Requirements 4.1.1.3.2 Environment 4.1.1.3.3 Radiation 4.1.1.3.4 Design Life-4.1.1.3.5 Operating Cycle 4.1.1.4 Instrumentation and control Reauirements 4-4 4.1.1.4.1 Power Sources '
4.1.1.4.2 Controls 4.1.1,5 Inscection and Testina Reauirements- 4-4 4.1.1.6 System Interface Recuirements 4-4 4.1.1.7 Physical Protection 4-5 4.1.1.7.1 Identification of Hazards 4.1.1.7.2 Protection Methods DRAFT i July 25,:1992
SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE
_ TABLE OF CONTENTS (Cont ' d)
Section Title Pace 4.1.1.3 Maintenance Provisions 4-6 4.2 PTPING 4-6 4.?.1 SYSTEM REQUIREMENTS 4-6 4.2.A.1 System Functions 4-6 i 4.2.1.2 Constraints 4-7 4.2.1.3 performance Recuirements 4-7 4.2.1.3.1 Capacity /Flowrate 4.2.1.3.2 Design Pressure and Temperature 4.2.1.3.3 Overpressure Protection 4.2.1.3.4 Water Chemistry 4.2.1.3.5 Erosion / Corrosion Pipe Wall Thinning 4.2.1.3.5.1 Erosion / Corrosion Susceptibility 4.2.1.3.5.2 Erosion / Corrosion Minimization 4.2.1.4 Operational Reauirements 4-9 4.2.1.5 Inst rumentation And Control Recuireme nt s 4-9 4.2.1.6 Insoection and Testing Recuirements 4- 9 4.2.1.6.1 Examination Requirements 4.2.1.6.2 Testing Requirements 4.2.1.6.3 Accessibility Provisions 4.2.1.6.4 Testing Provisions 4.2.1.7 System Interaction Recuirements 4-10 4.2.1.8 Physical Protection 4-11 4.2.1.9 yaintenance Provisions 4-11 4.2.1.9.1 Bypass / Isolation Provisions 4.2.1.9.2 Accessibility 4.2.1.9.3 Equipment Removal Provisions 4.2.1.9.4 Vent and Drain Connections 4.2.1.9.5 Removable Insulation 4.2.1.9.6 AIARA 4.3 HVAC DUCTWORK 4-12 4.3.1 SYSTEM REQUIREMENTS 4-12 4.3.1.1 System Functions 4-12 DRAFT ii July 25, 1992
SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE TABLE OF CONTENTS (Cont' d)
Section Title Pace 4.3.1.2 Constraints 4-12 4.3.1.3 Performance Recuirements 4-12 4.3.1.3.1 Capacity /Flowrate 4.3.1.3.2 Pressure Control 4.3.1.4 Operationa' Recui rement s *4-13 4.3.1.4.1 Radioactive Vapor / Steam Removal 4.3.1.5 Instrumentation and Control Recuirements 4-14 4.3.1.6 Insoection and Testino Recuirements 4-14 4.3.1.7 System Interaction Reauirements 4-14 4.3.1.8 Physica) Protection 4-14 4.3.1.9 Maintenance Provisions 4-14 4.3.1.9.1 Bypass / Isolation Provisions 4.3.1.9.2 Accessibility 4.3.1.9.3 Equipment Removal Provisions 4.3.1.9.4 Insulation 4.3.1.9.5 ALARA 4.3.1.10 Fire Protection 4-15 4.3.2 CONNECTIVITY 4-16 4.4 ELECTRICAL CABLE TRAYS / CONDUIT 4-16 4.4.1 SYSTEM REQUIREMENTS 4-16 4.4.1.1 System Functions 4-16 4.4.1.2 Eculement Selection 4-16 4.4.1.3 Environmental Recuirements 4-17 4.4.1.4 Seoaration Recuirements 4-17 4.4.1.4.1 Physical Separation 4.4.1.4.1.1 Fire Protection 4.4.1.4.1.2 Flood Protection 4.4.1.4.2 Electrical Separation 4.4.1.4.2.1 Segregation of Voltage Levels 4.4.1.4.2.2 Safety Channels 4.4.1.4.2.3 Safety /Non-safety Related DRAFT iii July 25, 1992 1
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SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE TABLE OF CONTENTS (Cont ' d)_
Section Title Page 4.4.1.5 Physical Protection 4-19 4.4.1.6 Interface Requirements 4-19 4.4.1.7 Insoection and Testing Recuirements 4-20
4.5 REFERENCES
4-20 5.0 DISTRIBUTION SYSTEMS INTERACTION CONSIDERATIONS. 5-1 5.1 GENERAL 5-1 5.1.1 RELATIVE ELEVATIONS 5-1 5.1.2 STRUCTURAL INTERACTIONS 5-1 5.1.2.1 Connectivity 5-1 5.1.2.2 Hazard Protection 5-1 5.1.2.2.1 Flood Protection 5.1.2.2.2 Fire Protection ~
5.1.2.2.3 Missile Protection 5.1.2.3 Divisional /Ouadrant Separation 5-2 5.1.2.4 Proximity To Succort Structures 5-2 5.1.3 SEGREGATION 5-2 I
5.1.3.1 Seismic /Non-seismic 5-2 5.1.3.2 Radiation 5-2 5.1.3.3 Hich Enercy Lines 5-3 5.2 FIPING 5-3 5.2.1 EQUIPMENT LOCATIONS 5-3 !
5.2.1.1 Accessibility 5-3 5.2.1.2 Labyrinths 5-3 5.2.1.3 Ecuioment Removal Provisions 5-3 5.2.1.4 Curbs 5-3 DRAFT iv July 25, 1992
i 4 SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE
~
l TABLE OF CONTENTS (Cont'd)-
I Section Title Pace L
, 5.2.1.5 Raised Base Plates 5-4 5.2.1.6 Elevation Relationshios .5-4 5.2.1.6.1 Net Positive Suction Head 5.2.1.6.2 Drains _and Sumps 5.2.1.6.3 Tank Overflow Provisions 5.2.1.7 Electrical Power Provisions 5-4 5.2.2 PIPE SLEEVES 5 ,4 5.2.2.1 Locations 5-5 5.2.2.1.1' General 5.2.2.1.2 Core Drill-5.2.2.2 Sleeve Confieurations 5-7 5.2.2.3 Insoection Accessibility 5-7 5.2.2.4 Sizing- 5-7 5.2.2.4.1 Insulation 5.2.2.4.2 Tolerances 5.2.2.4.3 Excessively Large Sleeves 5.2.2.5 Soecifications 5-10 5.2.3 FLOODING PROTECTION 5-10 5.2.3.1 Areas Of Interaction 5-11 5.2 3.1.1 Moderate Energy Pipe' Ruptures 5.2.3.1.2 Inadvertent-Actuation of Fire Protection System 5.2.3.1.3 Inadvertent Actuation of Containment Spray 5.2.3.2 Evaluation of Water Sorav Effects 5-11 5.2.3.2.1 Damage Assessment 5.2.3.2.1.1 -Equipment 5.2.3.2.1.2 Instrumentation 5.2.3'2.1.3 . Valves 5.2.3.3 Flooding Prevention / Protection -- 5-12 5.2.3.4 Other Flooding Prevention / Protection Methods 5-12 5.2.3.4.1 Component Qualification 5.2.3.4.2: Spray Shields DRAFT v July 25, 1992
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SYSTEM 80+" DESIGN CERTIFICATION DISTRIGUTION SYSTEMS DESIGN GUIDE TABLE 0F CONTENTS (Cont ' d)
Secticn Jitle Pace 5.2.3.5 Floer Drains 5-12 5.2.3.6 Floodina Isolation 5-13 5.2.4 EMBEDDED PIPING 5-13 5.2.4.1 Pioina/ concrete Interaction 5-13 5.2.4.2 Embedded Drains 5-13 5.2.5 BURIED PIPING 5~15 5.2.5.1 Freeze Protection 5-15 5.2.5.2 Insoection and Access Reauirements 5-15 5.2.5.3 Physical Protection 5-15 5.2.5.4 Seismic Interaction With Structures 5-17 5.2.6 EXPOSED PIPING 5-17 5.2.6.1 Freeze Protection 5-17 5.2.6.2 Physical Protection 5-17 5.2.7 FIRE PROTECTION 5-18 5.2.7.1 Plant Lavout 5-18 5.2.7.2 Fire Protection Sorinkler System 5-18 5.2.7.3 Fi- Protection Valves 5-18 5.2.7.4 Hose Reel Cabinets 5-18 5.2.7.5 Fire Seals 5-18 5.2.7.5.1 Boot Seal 5.2.7.5.2 Fire Seal Foam 5.2.7.6 Drains 5-19 5.2.7.7 Flushino and Testing Provisions 5-19 5.2.7.8 Fire Barrier Penetrations 5-19 5.2.7.8.1 Design Considerations 5.2.7.8.2 Piping Penetrations Subject To Movement DRAFT vi July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTR 7BUTION SYSTEMS DESIGN GUIDE TABLE OF CONTENTS (Cont' d)
Section Title Pace 5.2.7.9 Other Fire Protection Interaction. 5-20 Considerations 5.2.7.9.1 Fire Hazard Prevention 5.2.7.9.2 Explosion Prevention 5.2.7.9.3 Personnel Protection From Exposuee to Incapacitating Gases 5.2.8 PIPING INTERACTION WITH ELECTRICAL 5-20 EQUIPMENT / CABLE 5.2.8.1 Electrical Eculoment Interaction 5-20 5.2.8.1.1 Piping Guidelines 5.2.8.1.2 Guideline Compromises 5-21' 5.2.8.2 Cable Trav Interaction 5.2.8.3 Other Pinina Interaction considerations 5-21
. 5.2.8.4 Seoaration of Electrical Components 5-22
- 5.2.8.5 Fiber Optic Cable Interaction 5-22 i
5.2.9 PIPING INTERACTION WITH HVAC 5-22 F'sUIPMENT/DUCTWORK 5.2.9.1 General 5-22 5.2.9.2 Access to Dameers and Other HVAC Equipment 5-22 5.2.10 POSTULATED PIPE BREAKS 5-22 5.3 HVAC DUCTWORK 5-22 i
5.3.1 HVAC EQUIPMENT LOCATIONS 5-22 5.3.1.1 Accessibility 5-22 J
5.3.1.2 Space Limitations 5-23 5.3.1.3 Eculement Removal Provisions 5 1 5.3.1.4 ALARA 5-23 5.3.1.5 ectrical Power Provisions 5-23 5.3.1.6 Chilled water 5-23 e
DRAFT vii July 25, 1992
SYS'11!:M 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUi'DE TABLE OF CONTENTS (Cont ' d)
Section Title Pace 5.3.1.7 Drain Provisions 5-23 5.3.2 STRUCTURAL INTERFACE 5-24 5.3.2.1 Wall / Floor Ooeninos 5-24 5.3.2.2 Structural Loadina 5-24 5.3.2.3 Fire Protection 5-24 5.3.3 MECHANICAL INTERFACE 5-24 5.3.3.1 Picina Interface 5-24 5.3.3.2 Electrical Cable Trav/ Conduit Interface 5-24 5.4 ELECTRICAL CARLE TRAYS / CONDUIT 5-24 5.4.1 ELECTRICAL EQUIPMFN1 LOCATION 5-24 5.4.1.1 Space Allocation 5-24 5.4.1.2 Space Limitations 5-25 5.4.1.3 Connectivity 5-25 5.4.1.4 Accessibility 5-25 5.4.1.4.1 Maintenance Previsions 5.4.1.4.2 Equipment Removal Provisions 5.4.2 STRUCTURAL INTERACTION 5-25 5.4.2.1 Wall / Floor Oneninas 5-25 s .3.2.2 Structural Loadina 5-25 5.4.2.3 Supoort/ Restraints 5-25 5.4.2.4 Eculoment Bases 5-26 5.4.2.5 Embedded Conduit 5-26 5.4.2.6 Groundino System 5-26 DRAFT viii July 25, 1992
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! SYSTEN;80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE f
l TABLE OF ' CONTENTS - (Cont' d) 1 4
! Section Title Pace '
l l 5.4.3 MEC'ANICAL INTERACTION
. 5-26 i-i 5.4.3.1 Pipino Interaction 5 f. 5.4.3.1.1 Temperature Considerations '
! 5.4.3.1.2 Accessibility for Maintenance and-Testing 1
l
5.5 REFERENCES
- 5-26 i
}
! 6.0 DISTRIBUTION SYSTEMS ROUTING GUIDELINES 1 i
! 6.1 GENERAL 6-1 l
- b.1.1 PIPING /DUCTWORK/ CABLE-TRAY. RELATIVE 6-1
{
' ELEVATIONS
- 6.1.2 DIVISIONAL AND QUADRANT SEPARATION 6-1 ,
! 6.1.3 STANDARD COMPONENTS 6 :
- 6.1.3.1 Pipino_ 6-1 5
[ 6.1.3.2 Fittinas .6-1 1 6.1.3.3 Valves 6-1
- i .
I 6.1.3.4 Pipe Succorts 6-3 t 6.1.3.5 HvAC Comnonents 6-3' l
l 6.1.3.6 Electrical Comoonents 6-3 u
! 6.1.4 CONSTRUCTABILITY 6-3 i
j 6.1.4.1 . Tolerances 6-3 i
j 6.1.4.2 Standard comoonents 6-3
- 6.1.4.3 Accessibility 6-3l l 6.1.4.3.1 Clearance
! 6.1.4.3.2 Testing Provisions i-6.1.4.4 Interferences 6 !
i t
f 3.
j DRAFT ix July 25, 1992--
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SYSTEM 80+" DESIGN ::ERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE TABLE OF CONTENTS (Cont ' d)
Section Title Pace 6.1.5 SEGREGATION 6-4 6.1.5.1 Seismic /Non-seismic 6-4 6.1.5.2 Radioactive /Non-Radioactive Pinino 6-4 6.1.6 SUPPORTABILITY 6-4 6.1.6.1 Proximity to Snocort Structures 6-4 6.1.6.2 Base Plate Provisions 6-4 6.2 _P_I,P I NG 6-5 6.2.1 EQUIPMENT CONSIDERATIONS 6-5 6.2.1.1 Eouirnent Arrancement 6-5 6.2.1.1.1 Accessibility 6.2.1.1.2 Pull Space 6.2.1.1.3 Maintenance 6.2.1.2 Connectino Picino Requirements 6-5 6.2.1.2.1 Nozzle Loads 6.2.1.2.2 End Connections 6.2.1.2.3 Heat Tracing 6.2.1.2.3.1 Requirements 6.2.1.2.3.2 Steam Tracing Of Pipelines 6.2.1.2.3.3 Electrical Pipe Heating 6.2.1.3 Flowm6ters 68 6.2.2 VALVES 6-8 6.2.2.1 valve Functions 6-8 6.2.2.1.1 Gate Valve 6.2.2.1.1.1 Solid Wedge 6.2.2.1.1.2 Flex-Wedge and Split Wedge 6.2.2.1.1.3 Double Disc 6.2.2.1.1.4 Conduit 6.2.2.1.2 Globe Valve 6.2.2.1.2.1 Horizontal Globe 6.2.2.1.2.2 Y-Globe 6.2.2.1.2.3 Angle Globe 6.2.2.1.2.4 Y-Angle Globe DRAFT x July 25, 1992
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l SYSTEN 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE l ._
TABLE OF CONTENTS-1 Cont'd) i i
! Section Title - g h 6.2.2.1.3~ Check Valve
- 6.2.2.1.3.1 Swing Check.
f- 6.2.2.1.3.2 Lift Check l 6.2.2.1.3.3 Tilting Disc. Check i
! 6.2.2.1.4 Plug Valve
! 6.2.2.1.5 Butterfly Valve
! 6.2.2.1.6 Diaphragm Valve
- 6.2.2.1.7 Ball Valve
- 6.2.2.1.8 Relief Valve ~
j 6.2.2.1.9 Safety Valve j 6.2.2.1.10 Safety-Relief Valve-1 6.2.2.1.11- Control Valve i 6.2.2.1.12 Solenoid-Valve t
! 6,2.2.2 Valve Orientation considerations 6-13 j 6.2.2.2.1 valve Types i 6.2.2.2.1.1 Gate Valve i 6.2.2.2.1.2 Globe Valve
! 6.2.2.2.1.3 Check Valve 6.2.2.2.1.4 Plug Valve
[.
6.2.2.2.1.5 Butterfly Valve j 6.2.2.2.1.6 Diaphragm Valve
- 6.2.2.2.1.7 Ball Valve l- 6.2.2.2.1.8 Relief Valve j 6.2.2.2.1.9 Safety Valve j 6.2.2.2.1.10 Safety-Relief Valve .
J 6.2.2.2.1.11 Control Valve l 6.2.2.2.1.12 Solenoid valve 6.2.2.2.2 -Valve Body-
! 6.2.2.2.3 Operators j 6.2.2.2.3.1 Electrohydraulic
}' 6.2.2.2.3.2 Electric Motor-Operated 6.2.2.2.3.3- Chain Wheel Operator-6.2.2.2.3.4 -Pneumatic Piston Operators I
6.2.2.2.4 End Connections 6.2.2.2.5' Manufacturer's Instructions-i .
j 6.2.2.3 Valve Location Considerations 16-25 i 6.2.2.3.1- Valve Arrangement-l 6.2.2.3.1.1 'Line Valves
! 6.2.2.3.1.2 Butterfly-Valves-
! 6.2.2.3.1.3- Control. valves l
t
! DRAFT xi July 25, 1992 4
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-SYSTEM 80+". DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE i TABLE OF CONTENTS (Cont ' d) ,
4 f
Section Title gggg, j 6.2.2.3.2 Maintenance !
6.2.2.3.2.1 Location Requirements !
6.2.2.3.2.2 . Removal Requirements ~i 6.2.2.3.2.3 Valve Type i 6.2.2.3.2.3.1 Gate Valve 1 6.2.2.3.2.3.2 Globe Valve (
6.2.2.3.2.3.3 Check Valve .
6.2.2.3.2.3.4 Plug Valve _ [
6.2.2.3.2.3.5 Butterfly valve- ;
6.2.2.3.2.3.6 Diaphragm Valve ;
6.2.2.3.2.3.7 . Ball Valve ;
6.2.2.3.2.3.8 Pressure Relief Valve i 6.2.2.3.2.3.9 Control Valve !
6.2.2.3.2.3.10 Solenoid Valve [
6.2.2.3.2.3.11 Pressure Seal Valve i 6.2.2.3.3- Operability ;
6.2.2.3.4 Accident Accessibility. !
6.2.2.3.5 Equipment Proximity j i
6.2.2.4 Seismic Acceleration- 6-33 .l 6.2.2.5 Water Hammer considerations 6-33 :
i 6.2.3 SUPPORT GUIDELINES 6-33: !
6.2.3.1 taneral Guidelines 6-33 f 6.2.3.1.1 Grouping and Locations ;
6.2.3.1.2 Clearances !
6.2.3.1.3 Piping ;
6.2.3.2 Snubber Minimization 6-59 .
6.2.3.3 Piping Desian by Analysis 6-59 6.2.3_.3.1 Seismically Supported Pipe- -:
6.2.3.3.2 Vertical Supports =
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1 6.2.3.3.2.1 -Support Locations !
6.2.3.3.2.1.1 Concentrated Loads l 6.2.3.3.2.1.2 Equipment. Connections ;
6.2.3.3.2.1.3 Terminal Ends--
i- 6.2.3.3.2.1.4- Vertical ~ Piping l
- 6.2.3.3.3 Lateral Supports (Seismic) l 6.2.3.3.3.1~ Concentrated Loads .
6.2.3.3.3.2 Support-Spacing 6.2.3.3.3.3 Equipment Nozzles. j i
DRAFT xii July-25, 1992' a.__..__.__._.,.___;._..__..,___._
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SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE TABLE OF CONTENTS (Cont'd)
! Section Title Pace 6.2.3.3.4 Non-Seismically Supported Pipe
- 6.2.3.3.5 Leak-Before-Break Considerations 6.2.3.4 gang succort criteria 6-69 6.2.3.4.1 Gang Supported Pipe 6.2.3.4.2 Routing Gang Supported Pipe 6.2.3.5 Non-seismic Ploino 6-69 6.2.3.5.1 Routing Considerations 1
6.2.3.5.2 Interaction Analysis l 6.2.3.5.2.1 Non-Seismic Cable Tray and HVAC Duct 6.2.3.5.2.2 Hangers 6.2.3.5.2.3 Mechanical Connections 6.2.3.5.2.4 Rigid Constraint j 6.2.3.5.2.5 Piping Area of Influence 6.2.3.5.2.5.1 Arrest
- 6.2.3.5.2.6 Seismic /Non-Seismic Interaction 6.2.3.5.3 Targets 6.2.3.5.4 Dar age Assessment 6.2.3.5.4.1 Piping 6.2.3.5.4.2 Valves
, 6.2.3.5.4.3 Electrical Equipment and Instrumentation l 6.2.3.5.4.4 Mechanical Equipment l 6.2.3.L.5 Protection 6.2.3.5.5.1 Pipe Rerouting 6.2.3.5.5.2 Classification of Pipe Supports 6.2.3.5.5.3 Deflector Shields
- 6.2.3.5.5.4 Impact darlysis 6.2.3.6 Hydrostatic Testina Provisions for 6-72 Steam Pioing 6.2.4 ALARA 6-73 6.2.4.1 General 6-73 6.2.4.2 Radioactive Pipe Routina 6-73
, 6.2.4.2.1 Radiation Zones / Personnel Areas 6.2.4.2.2 Fluid Radiation Intensity 6.2.4.2.2.1 Reactor Coolant Prior to Processing
- 6.2.4.2.2.1.1 Pipe Area i 6.2.4.2.2.1.2 Pipe Configuration l
I DRAFT xiii July 25, 1992 I
SYSTEM 80+5 DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE TABLE OF CONTENTS (Cont'd) i Section Title face 6.2.4.2.2.2 Spent Resins 6.2.4.2.2.2.1 Pipe Area '
6.2.4.2.2.2.2 Pipe Configuration 6.2.4.2.2.3 Diluted and Processed Fluid 6.2.4.2.2.3.1 Pipe Area 6.2.4.2.2.3.2 Pipe Configuration 6.2.4.2.2.4 Concentrates 6.2.4.2.2.4.1 Pipe Area ;
6.2.4.2.2.4.2 Pipe Configuration 6.2.4.2.2.5 Post-LOCA Fluid ,
6.2.4.2.2.5.1 Pipe Area i 6.2.4.2.2.5.2 Pipe Configuration 6.2.4.2.3 Field Routing 6.2.4.3 Sleeve and Ooenina Location 6-77 6.2.4.3.1 Sleeve Selection 6.2.4.3.2 Scattering Considerations
- 6.2.4.3.3 Streaming Considerations 6.2.4.4 General Plant Arrancement 6-77 6.2.4.4.1 Additional Shielding for High Radiation Components !
6.2.4.4.2 Labyrinths 6.2.4.4.3 Sleeves 6.2.4.4.4 Isolation of Components 6.2.4.4.5 Pipe Chases 6.2.4.4.6 Sampling Rooms ,
6.2.4.4.7 Curbing Around Tanks Containing-Radi:::tive Liquid or Slurries 6.2.4.5 Maintenance Considerations 6-80 -
6.2.4.5.1 Vendor-Specified Removal Space 6.2.4.5.2 Accessibility 6.2.4.5.3 Equipment Separation in Compartments ,
6.2.4.5.4 Non-Radioactive Piping and Components 6.2.4.5.5 Direct Drive Fans 6.2.4.6 Valve Shielding 6-81 6.2.4.6.1 Valve Galleries G.2.4.6.2 Valve Operator Rooms 6.2.4.6.3 Remote Valve Operators -
DRAFT xiv July 25, 1992
i SYSTEN 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE TABLE OF CONTENTS (Cont ' d) i Section Title Pace 6.2.4.7 Mechanical Comoonents 6-83 6.2.4.7.1 Pumps 6.2.4.7.1.1 Low Points 6.2.4.7.1.2 Leakage 6.2.4.7.2 Heat Exchangers 6.2.4.7.3 Demineralizers 6.2.4.7.4 Tanks ,
6.2.4.7.5 Concentrators :
6.2.4.7.6 Strainers 6.2.4.7.7 Filters 6.2.4.7.8 Valves l
6.2.4.8 Protection 6-85 6.2.4.8.1 Pipe Rerouting 6.2.4.8.1.1 Radiation Zone Violations t 6.2.4.8.1.2 Streaming
- 6.2.4.8.1.3 Crud Traps t
6.2.4.8.2 Wall Construction or Relocation 6.2.4.8.3 Lead Shielding i
6.2.5 CONSTRUCTABILITY 6-86 6.2.5.1 Standard Comeonents 6-86 6.2.5.2 Pioe Assemb1v 6--86 ;
6.2.5.2.1 Banked Piping Assemblies 6.2.5.2.1.1 Field-Routed Piping 1 6.2.5.2.1.2 Piping in Trenches 6.2.5.2.1.3 Elevations ,
6.2.5.2.2 Pipe Bends +
6.2.5.2.2.1 Radius Bends t 6.2.5.2.2.2 Sloped Piping :
6.2.5.2.2.2.1 Socket Weld Piping !
6.2.5.2.2.2.2 Butt Weld Piping I 6.2.5.2.2.2.3 Arced Piping ,
6.2.5.2.2.3 Bend Constrain *s 6.2.5.2.2.3.1 Bend Clearances 6.2.5.2.2.3.2 Bend Deflection 6.2.5.3 Construction Assembly 6-91 ?
6.2.5.3.1 Layout 6.2.5.3.1.1 Fitting-to-Fitting Restrictions
-DRAFT xv July 25, 1992
SYSTF.M 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE
_ TABLE OF CONTENTS (Cont'd)
Section Title Pace 6.2.5.3.1.2 Spool Pieces 6.2.5.3.1.2.1 Construction Fit-up 6.2.5.3.1.2.2 Minimum Spool Pieces 6.2.5.3.2 Equipment 6.2.5.3.2.1 Equipment End Connections -
6.2.5.3.3 Tolerances 6.2.5.3.4 Weld Types '
6.2.5.3.4.1 Field Welding Provisions 6.2.5.3.4.2 Minimize Field Welds 6.2.5.3.4.3 Butt Welds 6.2.5.3.5 Insulation Allowances 6.2.5.4 Accessibility for Construction 6-98 6.2.5.4.1 Clearance 6.2.5.4.2 Flanges 6.2.5.4.3 Valves / Isolation 6.2.5.4.4 Door Swing Space 6.2.5.4.5 Testing Provisions 6.2.5.4.6 Inspection Provisions 6.2.6 ACCESSIBILITY FOR INSERVICE INSPECTION 6-101 6.2.6.1 Clearance For Inscection Eculement 6-101 6.2.6.2 Parallel Pine Spacine 6-101 ,
6.2.6.3 Structural Clearance 6-101 6.2.6.4 Discontinuities 6-102 i
6.2.6.5 Ploe Chases and Trenches 6-102 6.2.6.5.1 Horizontal Pipe Chase i 6.2.6.5.2 Vertical Pipe Chase 6.2.6.5.3 Trenches 6.2.6.6 Insulation 6-108 t
6.2.6.7 Guard Pioe Interference 6-108 6.2.6.8 Penetrations 6-108 6.2.6.8.1 Containment Penetrations I
6.2.6.8.2 Wall and Sleeve Requirements ,
L l
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DRAFT xvi July 25, 1992
SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE
~
TABLE OF CONTENTS (Cont ' d)
Section Title Pace 6.2.7 TESTING PROVISIONS 6-108 6.2.7.1 Preservice Testino 6-112 6.2.7.1.1 Hydrostatic Testing 6.2.7.1.1.1 High Point 7ents 6.2.7.1.1.2 Low Point Drains 6.2.7.1.1.3 Instrumentation 6.2.7.1.1.4 Isolation 6.2.7.1.1.5 Steam Piping 6.2.7.1.2 Operability Testing 6.2.7.1.3 Inservice Testing 6.2.7.1.3.1 Bypass / Isolation Capability 6.2.741.3.2 Full-Flow Pump Testing 6.2.7.1.3.3 Instrumentation 6.2.7.1.3.4 Accessibility 6.2.8 EROSION / CORROSION PIPE WALL THINNING 6-113 PROVISIONS 6.2.8.1 Routino Guidelines 6-114 6.2.8.1.1 Dry Steam Pipe Routing Guidelines 6.2.8.1.2 Wet Steam Pipe Routing Guidelines 6.2.8.1.3 Flashing Liquid Pipe Routing Guidelines 6.2.8.1.4 Liquid Pipe Routing Guidelines 6.2.8.2 Pipe Wall Thinninc Insoection-Provisions 6-115 6.2.8.3 Manway Access for Internal Inspections 6-115 6.2.9 WATER / STEAM HAMMER PREVENTION 6-115 6.2.9.1 Vertical Picina Loop Minimization 6-115 6.2.9.2 Hiah Point Ventino Provisions 6-115 6.2.9.3 Condensate Removal From Steam Pipinq 6-115 6.2.10 THERMAL STRATIFICATION MINIMIZATION 6-116 6.2.11 FIELD ROUTED LINES 6-116 6.2.11.1 Scoce 6-116 l
l DRAFT xvii July 25, 1992'
3
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SYSTEM 80+5 DESIGN CERTIFICATION [
DISTRICUTION SYSTEMS DESIGN GUIDE TABLE OF CONTENTS (Cont ' d)
Section Title Pace 6.2.11.2 Field Routino Constraints 6-116 6.2.11.2.1 Non-Safety Related .
6.2.11.2.2 Cannot Interact With Safety Related .
Equipment ;
6.2.11.2.3 Does Not Require Analysis 5 6.2.11.2.4 Cannot Carry Radioactive Fluids ;
6.2.11.2.5 Small Diameter 6.2.11.2.6 Not Required Early In Construction F 6.2.11.3 Field Routina Desion Recuirements 6-118 I 6.2.11.4 Interface Recuirements 6-119 6.2.".2 PUMP SUCTION PIPE ROUTING 6-119 ;
i 6.2.13 FLOOD PROTFCTION 6-119 i 6.3 HVAC DUCTWORK 6-119 ,
6.3.1 GENERAL GUIDELINES 6-119 6.3.1.1 Plant Arrancement 6-119 6.3.1.1.1 Reserve Space for Ductwork Early in Design Process 6.3.1.1.2 Minimize Duct Length 6.3.1.1.2.1 Equipment Placement 6.3.1.1.2.2 Utilize Pressure Differential to ;
Eliminate Ductwork I
6.3.1.3 Zine Limitations in containment 6-120 6.3.2 HVAC DUCTWORK DESIGN 6-120 .
6.3.3 MAINTENANCE PROVISIONS 6-120 .
6.3.3.1 Standard Comoonents- 6-120 .
6.3.3.2 Access for Insoection or Service 6-121 of Damners !
6.3.3.3 2decuate Soace for Damner Operators 6-21 6.3.3.4 Duct Location 6-121 6.3.3.4.1 Clearances 6.3.3.4.2 Leakage Tests l ?
DRAFT xviii July 25, 1992 f t- < --e- a - e a . ,- , e--,+- n -r-, n --w,, -,- e s.
SYSTZM 80+" DESIGN CERTIFICATION DISTRIEUTION SYSTEMS DESIGN GUIDE TABLE OF CONTENTS (Cont'd)
Section Title Pace ,
6.3.4 ALARA 6-121 6.3.4.1 Penetration Desian 6-121 6.3.4.2 Exhaust Systems 6-121 6.3.4.? Utilization of Necative Pressure 6-121 l 6.3.5 SUPPORTS AND RESTRAINTS 6-122 ,
6.3.5.1 Desian/ Analysis Criteria, Methods, 6~122 and Philosoohy 6.3.5.1.1 Function and Classification 6.3.5.1.1.1 Horizontal Duct Runs 6.3.5.1.1.1.1 Vertical Support / Restraints 6.3.5.1.1.1.2 Lateral Support / Restraints 6.3.5.1.1.1.3 Vertical-Lateral Support / Restraints 6.3.5.1.1.1.4 Axial Support / Restraints 6.3.5.1.1.1.5 Three-way Support / Restraints 6.3.5.1.1.2 Vertical Duct Runs (Risers) 6.3.5.1.1.2.1 Three-way Support / Restraints 6.3.5.1.1.2.2 Lateral-Vertical Support / Restraints 6.4 ELECTRICAL CABLE TRAYS / CONDUIT _ 6-127 6.4.1 CABLE TRAYS 6-127 6.4.1.1 Types 6-127 6.4.1.1.1 Safety-Related 6.4.1.1.2 Permanent Non-Safety Related 6.4.1.1.3 Non-Safety Related 6.4.1.2 Locations 6-127 6.4.1.2.1 Space Allocation 6.4.1.2.2 Physical Identification 6.4.1.2.3 Accessibility for Cable Pulls 6.4.1.2.4 Accessibility for Maintenance 6.4.1.3 Seoaration 6-128 6.4.1.3.1 Divisional / Quadrant Separation 6.4.1.3.2 Fire Protection 6.4.1.3.3 Cable Segregation by Voltage Levels DRAFT xix July 25, 1992
SYST5M 00+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE ,
TABLE OF CONTENTS (Cont ' d).
Section Title Pace .
6.4.1.4 Material Recuirements 6-129 r 6.4.1.4.1 Aluminum Limitations in Containment !
6.4.1.4.2 Zine Limitations in Containment 6.4.1.4.3 Cable Tray Materials ,
6.4.1.5 Cable Tray Fill Criteria 6-129 ;
t 6.4.1.5.1 Power Cables 6.4.1.5.2 Instrumentation and Control Cables ,
6.4.2 CONDUIT 6-130 6.4.2.1 Conduit Routina 6-130 ;
6.4.2.1.1 Bend Radius Guidelines 6.4.2.1.2 Water Exclusion Guidelines .
6.4.2.1.3 Pull Boxes !
6.4.2.2 Seoaration 6-130 I 6.4.2.2.1 Divisional / Quadrant Separation ;
6.4.2.2.2 Fire Protection 6.4.2.2.3 Embedded Conduit 6.4.2.3 Material Recuirements 6-131 6.5 INSTRUMENT LINES 6-131 6.5.1 DEFINITIONS 6-131 ;
6.5.1.1 Instrumentation 6-131
?
6.5.1.2 Instrument Lines 6-131 ;
6.5.1.2.1 Impulse Line- !
6.5.1.2.2 Control Lines 6.5.1.2.2.1 Supply Air Lines 6.5.1.2.2.2 Transmitted Air Lines ,
6.5.1.2.3 Sample Lines 6.5.1.2.4 Blowdown Lines 6.5.1.2.5 Filled Capillary Lines 6.5.1.3 Root valves 6-132 6.5.1.4 Chance in Direction 6-132 6.5.1.5 Track Suecorts 6-132 6.5.1.6 Tube Succorts 6-132 DRAFT xx July 25, 1992
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-SYSTEN 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN. GUIDE TABLE OF CONTENTS (Cont' d)
Section Title h 6.5.2 GENERAL 6-132 6.5.3 IMPULSE LINES 6-133 6.5.3.1 Slope Recuirements 6-133 6.5.3.2 Imoulse Line Size 6-133 6.5.3.3 Blowdown Lines 6-133 6.5.3.4 Process Tao Connections 64133 6.5.3.5 Instrument with Two Connections 6-134 6.5.4 CONTROL ~INES 134-6.5 4.1 Main Air Headers and Branch Lines 6-134 6.5.5 SAMPLE / PROCESS LINES 6-134 0
L 6.5.6 SEPARATION CRITERIA 6-134 6.5.7 EXPANSION COILS 6-134 6.5.8 SPECIAL. ROUTING AND SUPPORTING REQUIREMENTS 6-135 6.5.8.1 Free Tube Spans 6-135 l 6.5.8.2 Track Succorted Tubes 6-135 6.5.8.3 Sucoort and Mounting neautrements 6-135 6.5.9 TUBE BENDS 6-136 6.6 BEFEPINCES 6-136 7.0 DISTRIBUTION SYSTEMS ANALYSIS REOUTREMENTS 7-1 7.1 PIPING 7-1 7.1.1 GENERAL 7-1 7.1.2 DESIGN CONSIDERATIONS 7-1 7.1.2.1= Pressure 7-1 DRAFT xxi July 25, 1992
SYSTEM 80+5 DESIGN CERTIFICATION DISTRIOUTION SYSTEMS DESIGN GUIDE TABLE OF CONTENTS (Cont ' d) i Section Title Pace ,
7.1.2.2 Gravity 7-1 7.1.2.3 Thermal 7-1 7.1.2.4 Seismic 7-2 7.1.2.4.1 Seismic Anchor Movements 7.1.2.5 Wind / Tornado 7-2 ;
7.1.2.6 Fluid Transient Loadinos 7-2 7.1.2.6.1 Relief / Safety Valve Thrust 7.1.2.6.2 Water and Steam Hammer ,
7.1.2.6.3 Other Loadings 7.1.2.7 Pioe Break Loads 7-3 I 7.1.2.8 Thermal Stratification 7-3 7.1.2.9 Missile Loads 7-3 !
7.1.3 DESIGN LOAD COMBINAT70NS 7-3 7.1.4 ANALYSIS 7-3 7.1.4.1 Gravity Analysis 7-3 7.1.4.2 Thermal Analvsis 7-11 ,
7.1.4.2.1 Specific Thermal Requirements for Class 1 Piping 3 7.1.4.2.2 Thermal Stratification 7.1.4.3 Seismic Analysis 7-12 7.1.4.3.1 Static Analysis 7.] 4.3.2 Dynamic Analysis 7.1. 3.2.1 Response Spectrum Analysis 7.1.4.3.2.1.1 General 7.1.4.3.2.1.2 Response Spe;trum .
7.1.4.3.2.1.3 Spectrum Peak Broadening' 7.1.4.3.2.1.4 Damping 7.1.4.3.2.1.5 Modal Cutoff and Rigid Range Acceleration Effects ,
7.1.4.3.2.1.6 Modal and Direction Result Combination 7.1.4.3.2.1.7 Seismic Anchor Movements 7.1.4.3.2.1.8 Fatigue DRAFT xxii July 25, 1992
-SYSTEM 80+" DESIGN CERTIFICATION
. DISTRIBUTION SYSTEMS DESIGN-GUIDE
~
-TABLE OF CONTENTS (Cont' d)
S9ction Title Eggg 7.1.4.3.2.2 Time History Analysis 7.1.4.3.2.2.1 General 7.1.4.3.2.2.2 Piping Dynamically Decoupled-from the NSSS 7.1-.4.3.2.2.3 Piping Dynamically Coupled to the NSSS 7.1.4.4 Eculoment-Nozzles
- 7-17 7.1.4.5 Wind / Tornado Analysis -- 7-17 7.1.4.6 -Fluid Transient Analysis 7-17 7.1.4.6.1 Safety / Relief _ Valve Thrust 7.1.4.6.2 Water and' Steam Hammer Analysis-7.1.4.6.2.1 Water Hammer Forces 7.1.4.6.2.2 Steam Hammer Forces 7.1.4.7 Pipe Break Anal' , ,y,2 7-21 7.1.4.8 Hich Enercy and Moderate Enerav Recuirements 7-21 7.1.4.9 Non-Ricid Valves 7-21 7.1.4.10 Expansion Joints 7-24 7.1.5 ANALYSIS TECHNIQUES 7-24 7.1.5.1 Model Boundaries 7-24 7.1.5.2 Decoucline 7-24 7.1.5.2.1 General 7.1.5.2.2 Decoupling Criteria 7.1.5.3 overlancina 7-25 7.1.5.3.1 General _
7.1.5.3.2 .
Overlap Criteria 7.1.5.3.2.1 Restrained Elbow (or Tee) 7.1.5.4 In-line Anchors 7-26 7 .1. 5 . 5. Suonort considerations 7-29 7.1.6 ACCEPTANCE CRITERIA 7-29 7.1.6.1 ASME Class l'Pioinc 7-29 7.1.6.2 ASME Class-2 and 3 Picina 7-29 DRAFT xxiii: July 25, 1992.
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SYSTEM 80+5 DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 1 TABLE OF CONTENTS (Cont'd)
Section Title Pace 7.1.6.3 Allowable Nozzle Loads 7-29 7.1.6.4 Allowable Penetration Loads 7-29 7.1.6.5 Welded Attarhments 7-29 7.1.6.6 Functional Cacability Recuirements 7-30 7.1.6.7 Valve Reauirements 7-30
~
7.1.6.8 Exoansion Joint Requirements 7-30 7.1.7 PIPE SUPPORT DESIGN REQUIREMENTS 7-30 7.1.7.1 General 7-33 7.1.7.2 Desion Considerations 7-30 7.1.7.2.1 Deadweight Loads 7.i.7.2.2 Thermal Loads 7.1.7.2.3 Seismic Loads 7.1.7.2.4 Dynamic Fluid Loads 7.1.7.2.5 Wind / Tornado Loads 7.1.7.2.6 Missile Loads 7.1.7.2.7 Pipe Break Loads 7.1.7.2.8 Support Stiffness 7.1.7.2.9 Friction 7.1.7.2.10 Support Gaps 7.1.7.2.11 Support Orientation 7.1.7.2.12 Support Mass 7.1.7.2.13 Welded Pipe Attachments 7.1.7.3 Lead combinations 7-34 7.1.7.4 Acceotance Criteria 7-34 7.1.7.5 Jurisdictional Boundaries 7-34 7.1.8 POSTULATED PIPE BREAKS 7-36 7.1.8.1 Classification 7-36 1 7.1.8.1.1 High Energy 7.1.8.1.2 Moderate Energy l I
7.1.8.2 Postulated Ruoture Locations 7-37 l 7.1.8.2.1 Break Locations in ASME Class 1 Piping Runs ;
7.1.8.2.2 Break Locations in ASME Class 2 and 3 Piping l Runs !
i DRAFT xxiv July 25, 1992
l SYSTEM 800* DESIGN CERTIF2 CATION l DISTRIBUTION SYSTEMS DESIGN GUZDE l
TABLE OF CONTENTS (Cont ' d)
Section Titl Pace 7.1.8.2.3 Break Locations in Non-Safety Related Piping Runs 7.1.8.2.4 Break Locations In Piping Runs With Multiple ASME Code Piping Classes 7.1.8.2.5 Break Locations-7.1.8.2.6 Crack Locations 7.1.8.2.6.1 Through-Wall Cracks 7.1.8.2.6.2 Leakage Cracks 7.1.8.2.7 Piping Near Containment Isolation Valves 7.1.8.3 Pootulated Ruoture Conficurations 7-41 7.1.8.3.1 Break Configurations 7.1.8.3.2 Crack Configurations 7.1.8.4 Pioe Ruoture Loads 7-41 7.1.8.5 Pioe Ruoture Analysis 7-4? 33 7.1.8.5.1 Dynamic Analysis of Pipe Whip M 7.1.8.5.2 Dynamic Analysis of Unrestricted Pipes 7.1.9 LEAK-BEFORE-BREAK 7-44 7.1.9.1 Desian of Pipina Evaluated For Leak- 7-44 Before-Break 7.1.9.2 Pioina Desian Recuirementt 7-45 7.1.9.3 Picina Desian Procedure 7-45 7.1.10 SMALL BORE PIPING 7-46 7.1.11 TUBING 7-46 7.1.11.1 General 7-46 7.1.11.2 Free Tube Scans 7-46 7.1.11.3 Track Suecorted Tubes 7-48 7.1.11.3.1 Uninsulated Applications 7.1.11.3.2 Insulated and Heat Traced Applications 7.1.11.4 Suonort and Mounting Recuirements 7-50 DRAFT xxv July 25, 1992 e
SYSTEM rd'i+* DESIGM CERTIFICATION DISTRIDUTION SYSTEMS DESIGN GUIDE ;
_ TABLE OF CONTENTS (Cont ' dL Section Title Pace 7.2 HVAC DUCTWORK AND SUPPORT / RESTRAINTS 7-50 7.2.1 GENERAL 7-50 !
7.2.2 DESIGN CONSIDERATIONS 7-51 !
I 7.2.2.1 Gravity 7-51 7.2.2.2 Seismic 7-51 7.2.2.2.1 Safety-Related Ductwork 7.2.2.2.2 Overlap Regions 7.2.2.3 Thermal Exoansion 7-52 [
f 7.2.2.4 Internal Pressure 7-52 f
7.2.2.5 External Pressure Differential 7-52 7.2.3 DESIGN LOAD COMBINATIONS 7-52 7.2.4 ANALYSIS AND ACCEPTANCE CRITERIA 7-52 7.2.4.1 General 7-52 .
7.2.4.2 Damoina values 7-53 7.2.4.3 Static Coefficient Method 7-53 l 7.2.4.3.1 Static Coefficient Method Calculation 7.2.4.4 Dynamic Analysis Method 7-55 7.2.4.4.1 Dynamic Analysis Method Calculation -
7.2.5 ALLOWABLE STRESS CRITERIA 7-64 i
7.2.6 ALLOWABLE DEFLECTION CRITERIA 7-64 7.3 CABLE TRAY / CONDUIT AND SUPPORT / RESTRAINTS 7-64 7.3.1 GENERAL 7-64 i'
7.3.2 DESIGN CONSIDERATIONS 7-65 7.3.2.1 Gravity 7-65 7.3.2.2 Seismic 7-65 7.3.2.2.1 Safety-Related table Tray and Conduit 7.3.2.2.2 Overlap Regiorc
, DRAFT xxvi July 25, 1992
SYGTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGW GUIDE TABLE OF CONTENTS (Cont ' d)
Section Title gagg 7.3.2.3 Thermal Expansion 7-66 7.3.3 DESIGN LOAD COMBINATIONS 7-66 7,3.4 ANALYSIS AND ACCEPTANCE CRITERIA 7-66 7.3.4.1 General 7-66 7.3.4.' Dancino values 7-66
.3.4.3 jfatic Coefficient Method 7-67 7.3.4.3.1 Static Coefficient Method Calculation 7.3.4.4 Dynamic Analysis Method 7-67 7.3.4.4.1 Dynamic Analysis Method Calculation 7.3.5 ALLOWABLE STRESS CRITERIA 7-67 7.3.6 ALLOWABLE DEFLECTION CRITERIA 7-68
7.4 REFERENCES
7-68 APPENDICES TITLE 7A LEAK-BEFORE-BREAX 7B FUNCTIONAL CAPABILITY REQUIREMENTS DRAFT xxvii July 25, 1992
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SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE LIST OF TABL11 Table Title Pace 4.2-1 Recoramended Bulk Velocity Limits 4-9 l 6.2.1-1 Typical Allowable Nozzle Loads 6-5 6.2.3-1 Seismic Span Lengths (with 6-66 l concentrated weights) i 6.2.3-2 Suggested Pipe Support Spacing 6-67 6.2.5-1 Bend Radius 6-92 !
6.2.6-1 Minimum Structural Clearance 6-102 G.5-1 Minimum Tube Bending Radii 6-135 [
7.1.3-1 Design Conditions and Load Combinations 7-4 for ASME Class 1 Piping i 7.1.3-2 Code Compliance Criteria for ASME Class 1 7-6 Piping 7.1.3-3 Design Conditions, Load Combinations, and 7-9 Coda Compliance Criteria for ASME Class 2 and 3 Piping 7.1.7-1 Loading Conditions and Load Comoination 7-35 Requirements for ASME Code Class 1, 2, and 3 Piping Supports 7.1.9-1 System 80+ Piping Design Requirements 7-45 for LBB 7.1.11-1 Maximum Free Tube Span Lengths (L) 7-48 V
DRAFT xxviii July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE LIST OF FIGURES-Fiaure Title Pace 5.2.2-1 Pipe Sleeve Configurations 5-6 5.2.2-2 Boot Seal 5-8 5.2.2-3 Oval Sleeve Configuration 5-9 5.2.4-1 Embedded Piping Interface 5-14 5.2.4-2 Floor Drain Configuration 5-16 5.2.4-3 Equipment Drain Configuration 5-17 6.1.3-1 Non-standard Fittings 6-2 6.2.2-1 valve Body orientation 6-18 6.2.2-2 Check Valve Body Orientation 6-19 6.2.2-3 Relief Valve Body Orientation 6-21 6.2.2-4 Butterfly Valve Configuration 6-22 6.2.2-5 Valre Bonnet orientation 6-23 6.2.2-6 Non-preferred Bonnet Orientation 6-24 6.2.2-7 Line Valve Configuration 6-27 6.2.2-8 Control Valve Coafiguration 6-28 6.2.3-1 Support Grid Pattern 6-35 6.2.3-2 Typical Support Grid 6-36 6.2.3-3 Wall Column Pipe Clearance 6-37 6.2.3-4 Sleeve Clearances 6-38 6.2.3-5 Vertical Clearance Between Pipes 6-39 6.2.3-6 Non-preferred Configuration for Piping 6-40 With Large Movements 16.2.3-7 Typical Standard Hanger 6-40 2.2.3-8 Typical Standard Hanger 6-41 6.2.3-9 Typical Standard Snubber 6-43 DRAFT xxix July 25, 1992
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i SYSTEN 80+* DESIGN CERTIFICATION l DISTRICUTION SYSTEMS DESIGN GUIDE LIST OF FIGURES (Cont ' d)
Ficure Title Pacq l 6.2.3-10 Typical Standard Snubber 6-44 I 6.2.3-11 Typical Support / Restraint 6-45 6.2.3-12 Typical Support / Restraint 5-46 6.2.3-13 Typical Support / Restraint 6-47 6.2.3-14 Typical Support / Restraint 6-48 1
6.2.3-15 Typical Support / Restraint 6~49 l 6.2.3-16 Typical Support / Restraint 6-50 6.2.3-17 Typical Support / Restraint 6-51 !
6.2.3-18 Typical Support / Restraint 6-52 6.2.3-19 Typical Support / Restraint 6-53 6.2.3-20 Typical Support / Restraint 6-54 6.2.3-21 Typical Support / Restraint 6-55 6.2.3-22 Typical Support / Restraint 6-56 6.2.3-23 Typical Support / Restraint 6-57 6.2.3-24 Support Layout With Cable Tray 6-58 6.2.3-25 Spool Pieces for Hanger Supports 6-60 6.2.3-26 Seismic Piping Lenoth Minimization 6-61 6.2.3-27 Pipe Clearance 6-62 6.2.3-28 Pipe Clearance 6-63 6.2.3-29 Pipe Clearance for Gang Support 6-64 6.2.4-1 Sleeve for Shielded Area 6-78 6.2.4-2 Radiation Streaming 6-79 6.2.4-3 Valve Pull Space 6-82 i
r DRAFT xxx July 25, 1992
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l SYSTEM 80+5 DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUID3 LIST OF FIGURES (Cont ' d)_
E(oure Jitle Pace _
6.2.5-1 Field Routing Configuration 6-87 6.2.5-2 Pipe Trench Configuration 6-88 6.2.5-3 Common Support Configuration 6-89 6.2.5-4 Bend Clearances 6-93 6.2.5-5 Non-preferred Sleeve Configuration 6-94 6.2.5-6 Equipment Fit-up 6-95 6.2.5-7 Spool Piece Between Valves 6-96 6.2.5-8 Traceability Information 6-97 6.2.5-9 Flange Configuration 6-100 6.2.6-1 Parallel Pipe Spacing 6-104 6.2.6-2 Piping Discontinuities 6-105 6.2.6-3 Preferred Horizontal Chase Area 6-106 6.2.6-4 Preferred Vertical Chase Area 6-106 6.2.6-5 Preferred Trench Area 6-107 6.2.6-6 Guard Pipe Requirements for 6-109 Inservice Inspection 6.2.6-7 Containment Penetration Weld Areas 6-110 6.2.6-8 Access for Walls and Sleeves 6-111 6.3.5-1 Vertical Support / Restraint 6-123 6.3.5-2 Lateral Support / Restraint 6-123 6.3.5-3 Vertical-Lateral Support / Restraint 6-124 6.3.5-4 Axial Support / Restraint 6-124 6.3.5-5 Three-way Support / Restraint 6-125 6.3.5-6 Lateral-Vertical Support / Restraint 6-126 DRAFT xxxi July 25, 1992 1
___._____.___________]
SYSTEM 80+5 DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE LIST OF FIGURES (Cont'd)
FIFArt Til l.* Pace
' ,: <ri Wt u '
Steam Hammer Forces 7-22
1 E- ? F u rs ont Pressure Rise vs. Valve 7-23 diosing Time
.i S* Restrained Elbow 7-27 9.1.5-2 Restrained Tee 7-28 DRAFT xxxii July 25, 1992
_ _ _ m . _ _ _ __._ _. . _ . _ . _ . . _ . _ . _ _ . . _ _
f SYSTEM 80+C DESICll CERTIFICATIOli f DISTRIBUTIOli SYSTEMS DESIGli GUIDE '
l.0 PURPOSE I
The purpose of this design guide is to provide guidance for the '
mechanical and structural design of distribution systems (piping, i HVAC ductwork, and electrical cable trays / conduit) for the System 80+ standard design. The goal of using this guide is to provide a f well-defined, integrated, consistent, standardized, and optimized i design for System 80+ design certification. [
t I
If the guidance provided herein proves to be too conservative to uphold the goal for development of standardized distribution system designs for all potential sites, project management must be consulted.
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j' s
L f
t DRAFT 1-1 July 31, 1992 '
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SYSTEli 80+C DESIG!1 CERTIFICATIO!1 DISTRIBUTIOli SYSTE!4S DESIGli GUIDE 2.0 S_ COPE This design guido is to be used for the design of all System 00+
distribution systems. This guido covers the design process from incorporation of system requirements to analyses confirming the adequacy of the design. This design guido addresses both safety-related and non-safoty related distribution systems.
l This design guide providos recommanded design and analysis methods i and processos reflecting industry practico and liRC -approved critoria at the time of System 80+ design certification. Other proven derign and analysis methods and critoria, an demonstrated by industry practico and 11RC acceptanco at the timo of application, which also moet the purposo and intent' of this guido are acceptable.
Efforts have boon made to assure that the guidance provided by this document is consistant with the requiromonts provided in CESSAR-DC for safety-related distributions systems. Should thoro bo inconsistencies betwoon this design guido and CESSAR-DC, the requirements of CESSAR-DC shall prevail.
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DRAFT 2-1 July 31,- 1992
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SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE
3.0 INTRODUCTION
This design guide covers the design process from incorporating system requirements to the analyses verifying the design.
Licensing and safety issues (leak-before-break, postulated pipe breaks, etc.) are covered in detail in this' design guide.
Section 4.0 addresses the factors to be considered in incorporating system requirements such as safety class, seismic; category, separation and constraints.
Section 5.0 addresses system interactions to be considered in meeting the system requirements. These interactions are system requirements, however, they must be provided by_ other systems'or structures such as cross-connects to other systems, structural separation and electrical power requirements.
Section 6.0 provides guidelines and considerations in routing distribution systems. These guidelines are intended to integrate the design process and moet multiple requirements at once (e.g.,
use building structure for spatial separation, flooding prevention, and fire protection) rather than meeting each requirement individually. The goal of the integrated design process- is optimization while meeting _all pertinent requirements.
Section 7.0 describes the analyses.to verify the system design and routing. Pipe break considerations are covered in Section 7.1 for leak-before-break (LBB) and postulated pipe ruptures.
Interactions between systems and structures must be considered in the integrated design process. Considerations such as safety, maintainability, and constructability must be __ evaluated collectivelf rather than individually to obtain the optimum design.
This document addresses these interactions, and incorporation of the guidelines presented herein should minimize conflicting design requirements.
To distinguish between requirements that must be met and recommendations, the following conventions are used throughout this document. The term "shall" is used to denote requirements that are mandatory. The term "should" is used to denote recommendations that are not mandatory. The term "may" is used - to denote conditions that are permissible but not required.
The references listed at the end of' each section are current versions which were used in the_ development of.this design guide.
The year or version of- codes and standards that will be used in the final design will be determined by the approved versions 'in. effect at the time of the specific plant application._ _Thus, when codes and standards.are referred to in the design guide text, only the name is specified, not the version.
DRAFT 3-1 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 4.0 SYSTEM DESIGN CONSIDERATTONS, 4.1 GENERAL 4.1.1 SYSTEM REQUIREMENTS The detailed design of distribution systems requires careful consideration of the system design requirements. The system requirements are specified in the Design Certification System Requirements (DCSRs) developed for each system within the System 80+ design. The following system requirements are described in the DCSRs and should be considered when designing distribution systems.
4.1.1.1 System Fl.iction 4.1.1.1.1 Functions The system functions are fundamental in the system design. The system functions are qualitative in nature and only provide general system requirements. Specific requirements relating to these system functions are covered in other sectione. Where a system function is provided in combination with other system (s), the contribution by each system should be provided. See Sections 4.2.1.1, 4.3.1.1, and 4.4.1.1 for specific system functions.
4.1.1.1.2 Constraints The integrated design process should result in minimized system constraints. Conctraints on the system methods of meeting its design requirements can influence the design of the distribution system. Typical constraints include:
- Divisional Separation Precluding Cross-connects
- Electrical Power Limitations a Building Layout Limitations
- Temperature / Pressure Limitations
- Material Requirements See Sections 4.2.1.2 and 4.3.1.2 tor specific system constraints.
4.1.1.2 Performance Reauirements System or component performance requirements define how the component or system must perform, or what its capabilities must be i in order to perform its functional requirements. The following are performance requirements which can affect the design of distribution systems. An individual system or component can have ,
fewer or more performance requirements which require consideration.
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DRAFT 4-1 July 25, 1992
SYSTEM 80+5 DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE 4.1.1.2.1 Safety Classification The safety classifications of systems and equipment, as est ablished by ANSI /ANS-51.1, " Nuclear Safety Criteria for the Design of Stationary Pressurized Water Reactor Plants", should be used as a guide to the selection of codes, standards, and regulations for the design and construction of systems and their components. !
t 4.1.1.2.2 Seismic Classification I L
The seismic design classification system, as established in NRC f Regulatory Guide 1.29, " Seismic Design Classification", identifies !
those plant features that should be designed to withstand the effects of the Safe Shutdown Earthquake (SSE). Plant features not i required to withstand ;he SSE should be designed to appropriate !
static loads or comply with applicable building codes regarding i Seismic classifications, including Seismic seismic effects.
Category II, are described in CESSAR-DC, Section 3.2.1. .
4.1.1.2.3 Redundancy / Diversity Requirements l A component or system can require that other systems or components -
duplicate its essential function to the extent that either one may perform the required function regardless of the state of operation or failure of the other. The components or systems may or may not i be physically identical. System and component diversity should be specified where prevention of common mode failure is critical in !
overall plant core melt risk. ,
4.1.1.2.4 Capacity Requirements i System and component capacity requirements arc ..ey parameters that I affect system design. Capacities can include auch parameters as i head snd flow rate for a pump, load carrying capability for :
supports, air flow or cooling capacity for HVAC, or current and l voltage regulation of a power supply, i 4.1.1.2.5 Failura Considerations I The following failure considerations should be reviewed to dete rmine the impact they could have on the design of the distribution system:
A. Performance under conditions of single or multiple (active ;
and passive) failures. ,
B. Separation, protection, and design of components and '
pipjng to prevent multiple failures as a result of a single event. ;
C. Design margins to accommodate single failures.
DRAFT 4-2 July 25, 1992
,,- ,av ---*,-,a -w -u - , , , < ,
SYSTEN 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 4
D. Reliability performance.
E. Provisions to mitigate the effects of failures in the system on the remainder of the plant.
4.1.1.2.6 Design Basis Ever.ts and Transient Considerations System design basis events and design basis transients shall be considered in the design. These design basis events and transients l should either be enveloped or considered individually. l l
4.1.1.3 Operational Pecuirements l Operational requirements must be sufficiently defined to enable the designer to provide a detailed design. Following are areas in i which systems or components can have operational requirements. An I l
individual system or component can have fewer or more areas which should be considered.
4.1.1.3.1 Power or Cooling Requirements 1
There could be design requirements or limitations on available electric, pneumatic, hydraulic, or other power supplies and air or water cooling supplies. Considerations to ensure system requirements are met by interacting systems are described in Section 5.0.
4.1.1.3.2 Environment 4
Requirements or limitations can be imposed on the system due to the operating environment in which it must perform its function.
Environmental considerations are described in CESSAR-DC, Section l 3.11.
4.1.1.3.3 Radiation
- Requirements or limitations can be imposed on the system due to the operating radiation environment, which could affect the performance of the system (see Section 6.2.4) .
4.1.1.3.4 Design Life The System 80+ design operating life is '60 years. Provisions should be provided to replace components which cannot be designed for a 60 year operating life.
4.1.1.3.5 Operating Cycle Requirements or limitations can be imposed on the system due to the operating cycle of the system or components.
DRAFT 4-3 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIEUTION SYSTEMS DESIGN GUIDE 4.1.1.4 Instrumentation and Control Recuirements System instrumentation and control requirements must be considered in the design of the distribution system. Following are areas where systems or components can have instrumentation and control requirements.
4.1.1.4.1 Pesar Sources Power source requirements include normal onsite and/or offsite-AC power, emergency power, and special requirements for separate or diverse sources of power. .
4.1.1.4.2 Controls Control requirements of the system can impact other parts of'the system or other systems. Instrumentation may be required to provide system control and monitoring capability.
4.1.1.5 Inspection and Testina Recuirements Requirements can be -imposed on the system design to* enable or-facilitate the performance of required tests and inspections during fabrication, installation, and operation.
4.1.1.6 System Interface Recuirements Interface requirements are design fynctions or requirements which must be satisfied by the_ remainder of the plant design to ensure proper, safe, and reliable operation of a system or component. The distribution system design and operation-can be influenced by the-system interface requirements. Therefore,. the design of distribution systems should take into account the design functions and requirements of interfacing systems. The following interface requirements categories should be considered:
Power _
+- Protection-from Natural Phenomena-Protection from Pipe Failure Missiles 4
- Separation Connectivity
- Independence Thermal Limitations
- Monitoring
- Operation and Controls
- Inspe'ction and Testing DRAFT 4-4 July 25, 1992-
+
SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE
- Chemistry and Sampling
- Material
- System and Component Arrangement
- Radiological Waste
- Overpressure Protection Related Service
- Environmental
- Construction *
- Maintenance System interf ace considerations are described further in Section 5.0.
4.1.1.7 Physical Protection Systems and components important to safety require protection from hazards resulting from postulated events both internal and external to the plant. Physical protection is an important consideration in creating a detailed distribution system design. ANSI /ANS-58.3,
" Physical Protection for Systems and Components Important to Safety", shall be followed to establish physical protection criteria for systems and components important to safety in the plant. The following highlights from ANSI /ANS-58.3 are included here to aid the designer in identifying hazards and protection methods which could be relevant to the system being designed.
Refer to ANSI /ANS-58.3 for additional informati.on.
4.1.1.7.1 Identification of Hazards The following are some of the hazards, resulting from postulated events, which should be considered in designing distribution systems:
- Missiles
- Pressure, Pressure Differential Temperature
- Pipe Whip Fluid Jet
- Fire Radiation
- Steam or Humidity Chemical Attack
- Floading DRAFT 4-5 July 25, 1992 i
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE
- Debris Blockage 4.1.1.7.2 Protection Methods The following protection methods should be used to provide protection from hazards:
Distance ;
- Orientation
- Barriers
- Enclosures
- Restraints
- Hardening 4.1.1.8 Maintenance Provisions Requirements can be imposed on the system design to enable or facilitate system /compenent maintenance. Provisions for maintenance include features to reduce personnel radiation exposure .
when performing maintenance, design features or components required for maintenance activities (vents, drains, bypass / isolation !
provisions, equipment removal provisions), and accessibility.
4.2 EIPING 4.2.1 SYSTEM REQUIREMENTS 4.2.1.1 System Functions The function of the piping system drives the design. Specific requirements relating to system functions can impact the piping system design. The following are typical system functions associated with piping systems that should be addressed:
Cooling
- Heating -
- Purification
- Monitoring
- Lubrication
- Storage Pneumatic Supply Makeup i
- Recir'11ation DRAFT 4-6 July 25, 1992
SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 4.2.1.2 Constraints Constraints on the ability of the system to meet its design requirements can influence the design of the system piping. The following constraints are commonly imposed on piping system designs and should be considered:
- Friction Loss (L/D limits)
- Net Positive Suction Head (NPSH)
- Maximum Velocity Based on Noise and Friction Loss
- Erosion / Cot _osion Pipe Wall Thinning
- Water / Steam Hammer / Rapid Valve Actuation
- Piping Layout Restrictions 4.2.1.3 Performance Recuirements In addition to the general guidelines of Section 4.1.1.2, the following performance requirements are related to piping systems.
4.2.1.3.1 Capacity /Flowrate The primary performance requirement is usually system or component capacity. This capacity can be in the form of flowrate, cooling capacity or pressure. The capacity should either envelope all expected operating conditions or address each operating condition independently. The piping system design must provide the required capacity or flowrate.
4,2.1.3.2 Design Pressure and Temperature The maximum operating pressure and temperature will be determined by system requirements and component characteristics. The design pressure and temperature are required to determine pipe wall thickness, thermal expansion characteristics and overpressure provisions.
s 4.2.1.3.3 overpressure Protection Adequate overpressure protection is require'd to prevent exceeding the design pressure and possible failure of the piping system or individual components. .0verpressure protection shall be provided per the applicable design code, as follows:
A. ASME Boiler and Pressure Vessel (B&PV) Code,Section III for Class 1, 2, and 3 piping.
B. ASME B31.1, Power Piping for non-safety related piping.
DRAFT 4-7 July 25, 1992 j
l SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE C. ASME B&PV Code,Section VIII for pressure vessels.
4.2.1.3.4 Water Chemistry i
Water chemistry requirements and constraints (i.e., pH , oxygen :
level, or chloride content) may be specified along with the !
allowable limits. Water chemistry requirements should be used as [
input for material selection, monitoring requirements, and chemical i addition provisions. [
4.2.1.3.5 Erosion / Corrosion Pipe Wal) Thinning Currently operating auclear power plants have experienced pipe wall thinning in carbon steel piping and components, resulting in i unplanned piping- replacements and plant shutdowns. .
This i degradation is best prevented in the design stage by identifying- !
susceptible systems / components, and using appropriate preventative !
methods. -Design methods to preclude erosion / corrosion pipe wall I thinning are described below-and in Section 6.2.8.
4.2.1.3.5.1 Erosion / Corrosion Susceptibility ;
Systems susceptible to erosion / corrosion pipe wall thinning are [
t those with wet steam, flashing liquids,--or liquid flow with high localized velocities. These factors should be-considered along with water chemistry and usage-time to determine susceptibility and '
appropriate preventative methods. ,
4.2.1.3.5.2 Erosion / Corrosion Minimization j For systems susceptible to erosion /ccirrosion, the following methods T may be used to minimize degradatient ;
i A. Proper material selection is essential for the prevention !
of excessive pipe wall thinning and is the most practical I method in the design stage. Higher grade alloys involve more capital- cost- but lower inspection and piping replacement costs over the: life of the plant. Low alloy !
steel is significantly more resistanti to wall thinning !
than carbon steel, however the post-weld heat-treatment !
must be considered. Stainless steel is essentially immune i to erosion / corrosion. and should be used in the ~ most '
I susceptible areas. -
l B. Additional wall thickness may be specified to. accommodate .
a limited amount of wall thinning without violating code requirements. This method will- usually result- in i increased inspection requirements- over - the life of- the i plant to ensure - adequate wall thickness. These costs .!
should be compared ~to material upgrade costs to determine i the optimum design. !
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DRAFT 4-8 July 25,L 1992 l i I
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l SYSTEN-_80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 4 C. The bulk fluid velocity should be limited to prevent
?
excessive erosi on of the pipe wall. The following velocity limits should be_used for carbon steel piping:
]
! TABLE 4.2-1 i l j Recommended Bulk velocity L(mits 5ervice Y.elpsiti,y.
-l
- Steam Piping 150 ft/sec Water (Temperature < 300'F) 10 ft/sec ,
j Water (Temperature > 300'F) 10 - 20 ft/sec l j Recirculation Lines (Infrequent Use) 20 - 25 ft/sec J
D. Pipe routing guidelines to lower pipe wall' thinning ,
susceptibility are discussed in Section 6.2.8.1.
4.2.1.4 coerational Recuirements i
Operational requirements and limitations of the- system will influence the piping design. Typical operational requirements are 1 described in Section 4.1.1.3.
4.2.1.5 Instrumentation And Control Recuirerr3nts' Requirements related to instrumentation and controls can impact the design of the piping system. Refer to Section 4.1.1. 4 for the discussion of instrumentation and controls.
4.2.1.6 Inspection and Testina Reauirements Piping system features con be required solely to accommodate inspection and testing requirements . during fabrication, installation, and operation. Inspection and testing. requirements are contained in the-applicable piping code: ASME B&PV_ Code for.
Class 1, 2, and 3 piping; and ASME B31.1 for non-safety related
-piping. :
4.2.1.6.1 Examination Requirements The piping system _ designer should be_ cognizant:of. the examinations to be performed _on the system piping and.be f amiliar .. with the activities associated with the examinations in order to include any -
necessary features in the piping _ design to facilitate the l
DRAFT 4-91 hly 25, 1992 --
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SYSTEM 80+" DES 7GN CERTIFICATION DISTRICUTION SYSTF.MS DESIGN GUIDE examinations. The following are examinations commonly conducted on piping systems:
- Preoperational (NDE)
- Inservice Inspection (ISI) per ASME Section XI
- Visual Inspection of Raw Water Piping
- Pipe Wall Thinning Inspections !
4.2.1.6.2 Testing Requirements Certain testing requirements can necessitate special piping design features to facilitate testing activities. The piping system ,
designer should know what tests are applicable to the system and have an understanding of how the tests are performed. Familiarity with the required testing will aid the designer in creating a piping system which is conducive to testing. The following are ,
conmon test requirements associated with piping systems:
- Preoperational (Hydrostatic, operability, pre-critical vibration monitoring)
- Pump and Valve Inservice Testing (IST) per ASHE Section XI
- Leak Tests
- Full-Flow Pump Testing for ASME Class 1, 2, and 3 Pumps 4.2.1.6.3 Accessibility Provisions Teeting and inspection activities associated with piping systems require considerations for personnel and equipment access. Section 6.2.6 contains specific guidelines for providing access for inspection and testing activities.
4.2.1.6.4 Testing Provisions Piping system designs should include provisions for system and cmponent testing. The piping system designer should be familiar with testing applicable to the system and its components so that design features required to perform the tests will be included in the piping design. Section 6.2.7 contains design features to be considered when incorporating testing provisions in piping system designs.
4.2.1.7 Sys>em Interaction Recuirements Interacting rystem requirements should be considered when designing piping systems. The interaction requirements categories outlined in Section 4.1.1.6 should be reviewed to assist in determining what design features must be incorporated to accommodate interacting systems or components. Section 5.2 contains additional information l
pertaining to piping interaction considerations, l
i DRAFT 4-10 July 25, 1992 l
i SYSTEM 80&* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 4.2.1.d Physical Protection j Piping' systems can require hazard protection measures. If hazard protection is required, the guidelines of Section 4.1.1.7 should be used to er;ist in determining the type of hazard (s) which can influence the system and the general methods of protection.
4.2.1.9 Maint.> nance Provisions I
- Maintenance activities will be required over the life of the plant.
The following design features may be required to accommodate
- maint oance activities.
1 I
- 4.2.1.9.1 Bypesa/Isciation Provisions The ability to bypass or isolate system components and interfacing systers should be provided ithin the piping system to allow maintenanca to be perfcrmad.
) 4.2.1.9.2 Accessibility 4 Accessibility for maintecance activities shovid be provided.
4.2.1.9.3 Equipment Removal Provisions Equipment removal provisions should be provided. This includes lifting provisions, removal paths, and flanged equipment connections.
4.2.1.9.4 Vent anc Drain Connections
, The pil. ' '
system design should incorporate vent and drain connectic..s for performing maintenance on the piping system and its co nponent s .
. Personnel access should be also be considered for these connections.
4.2.1.9.5 Removable Insulation The piping system design should incorporate insulation removal where required to perform maintenance, inspections, or testing.
These locations should be provided with removable insulation to expedite maintenanco activities, reduce personnel radiation exposure, and reduce costs associated with insulation replacement.
4.2.1.9.6 AIJ2A Design features should be provided in piping system designs to reduce personnel exposure associated with maintenance activities.
Section 6.2.4 contains specific ALARA guidelines for reducing personnel radiaticn exposure during maintenance.
DRAFT 4-11 July 25, 1992
SY3 TEM 80+5 DESIGN CERTIFICATION DISTRICOTION SYSTEMS DESIGN GUIDE 4.3 HVAC DUCTWORK 4.3.1 SYSTEM REQUIREMENTS 4:3.1.1 System Functions The function of the HVAC system drives its design. Specific requirements relating to system functions can impact the ductwork system design. The following are typical HVAC system functions to be considered:
- ' Temperature / Humidity Control
- Normal / Essential
- Moisture Removal
- Radioactive Iodine Vapor and Solid Particulate Removal
- Ventilation Smoke Removal
- Pressure Control
+ Positive
+ Negative 4.3.1.2 Constraints Constraints on the system's means of meeting its design requirements can influence the design of the ductwork system. The following constraints are commonly imposed on ductwork system designs:
- Accepted Engineering Practices and Data (ASHRAE Handbooks and SMACNA Manuals)
- Friction Loss
- Velocity Constraints
- Sound Level Constraints
- Building Layout Restrictions / Space Availability
- Thermal Conductivity (Heat losses'or gains)
- System Balancing
- Fire and Smoke Control
- Adequate Air Distribution
- - Duct Leakage
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- Supports / Seismic Restraints DRAFT 4-12 July 25, 1992
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SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SY3fEMS DESIGN GUIDE 4.3.1.3 Performance Beauiremerits the general guidelines in Section 4.1.1.2 should be reviewed to determine the influence that the HVAC system's performance i
requirements have on the design of the system's ductwork.
4.3.1.3.1 Capacity /Flowrate Design parameters should properly address system operating 4 conditions. The following are typical HVAC capacities which may require consideration:
l J
- Volumetric Air Flow Rate (SCFM)
- Design Pressure (Inches of water gage) .
]
- Relative Humidity (Percent) i
- Heating / Cooling Capacity (BTU / hour)
- Safety / Seismic Classification
- Component Radiation Dose (); ads )
- Duct and Air Handling Unit (AHU) / Air Cleaning Unit Maximum Permissible Leak Rate
- Electrical Characteristics (Voltage, amperage, phase, maximum temperature rise) 4.3.1.3.2 Pressure Control I
Along with ventilation and cooling requirements, some HVAC systems
} are required to maintain a negative or positive pressure in specified areas. This pressure maintenance must be considered in the design, where applicable.
4.3.1.4 Operational Renuirements Consideration should be given to the operational requirements of tne system and their inf)uance on the ductwork design. Typical HVAC system operational requirements are described below and in Section 4.1.1.3.
4.3.1.4.1 Radioactive Vapor / Steam Removal In some areas, there is the potential for airborne radiation (i.e.,
due tc :adioactive_ fluid leakage), or steam removal (1.0, Loss-of--
Coolant-Accident) that would require the removal of radioactive iodina, solid particulates, or water vapor. This could result in the release of radiation to the environment, personnel exposure, or l equipment damage. Air cleaning units, which may consist of moisture separators, electric heaters, absolute (HEPA) filters, and carbon adsorbers should be used along with instrumentation, alarms, l
l DRAFT 4-13 July 25, 1992
SYSTEN 80+* DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE and control dampers to automatically route the air flow through the air cleaning unit when required, if the unit is normally bypassed.
4.3.1.5 Instrumentation and Control Reauirements Requirements related to instrumentation and control should be reviewed for their impact on the design of the ductwork system.
Refer to Section 4.1.1.4 for general guidelines to he considcred.
4.3.1.6 Inspection and Testino Reauirements Ductwork systems should be designed to accommodate inspection and testing requirements during fabrication, installation, and operation. The ductwork system designer ahould be aware of the testing and inspections performed on HVAC systema and components so that adequate design features can be incorporated in the system' to facilitate these activities.
Provisions should also be provided to allow performance testing of fans, filter units and dampers.
4.3.1.7 System interaction Reauirementi Interacting system requirements should be considered when designing ductwork systems. The interaction requirements categories outlined in Section 4.1.1.6 should be review'd by the designer to assist in determining what design features must be incorporated to accommodate interacting systems or components. Section 5.3 contains additional information pertaining to ductwork interaction considerations.
4.3.1.8 Physical Protection HVAC ductwork systems should be evaluated to determine if hazard protection measures are required. If the ductwork requires hazard protection, the guidelines of Section 4.1.1.7 should be used to assist in determining the type of hazard (s) which can influence the system and the general methods of protection available.
4.3.1.9 Maintenance Provisions Adequate design features should be provided,in the ductwork system design to support maintenance activities associated with the system and components (see Sections 6.3.3.2 and 6.3.3.3) . Accessibility for fan and damper inspections and maintenance should be provided along with filter changeout provisions, and heating / cooling coil removal provisions. The following design features should be considered when designing HVAC ductwork systems.
DRAFT 4-14 July 25, 1992
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SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 4.3.1.9.1 Bypass / Isolation Provisions The ability to bypass or isolate system components and interfacing systems should be provided within the ductwork systam to allow maintenance to be performed.
1 4.3.1.9.2 Accessibility a
Accessibility for required maintenance activities should be considered when designing ductwork systems.
Equipment Removal Provisions 4.3.1.9.3 I Equipment removal and replacement should be considered for all HVAC l ductwork systems. This includes lifting lugs and/or rigging provisions for all AHU/ air cleaning units. The use of multiple 1 modules with field joints should be used for large AHU/ air cleaning units rather than single modules to allow for initial placement and l removal of the unit. Removal paths for regular maintenance 1 components such as fan motors, cooling / heating coils, and filters should be provided.
4 Ductwork should be designed to avoid removable hatches, monorails, jib cranes, or other maintenance areas. If the ductwork should infringe on these areas, easily removable duct sections should be j used.
4.3.1.9.4 Insulation 4 Insulation should not be applied to the inside of ducts and housings where airborne radiation or personnel radiation exposure could occur. Materials applied to the outside of ducts and housings should not prevent access to any bolted construction joint, door, access hatch, or instrumentation that would penetrate 4
the housing or duct pressure boundary, which could result in exceeding allowable leakage rates.
4.3.1.9.5 ALARA Design features should be provided in ductwork system designs to reduce personnel exposure associated with maintenance activities.
Section 6.3.4 contains specific ALARA guidelines for reducir.g personnel radiation exposure during maintenance.
4.3.1.10 Fire Protection Due to ductwork penetrations through fire barriers being large, fire protection must be considered in the design. Ductwork routing 2 should minimize the number of penetrations through fire barriers.
Fire seals at the penetrations ano fire dampers must maintain the required fire barrier rating. A smoke purge exhaust system with smoke dampers should be considered where smoke migration is likely.
DRAFT 4-15 July 25, 1992
i SYSTEN 80+* DESIGN CERTIFICATION !
DISTRICUTION SYSTEMS DESIGN GUIDE 4.3.2 C0!mCCTIVITY Due to the size of HVAC equipment and ductwork, system connectivity !
is vital. This is best accomplished by proper equipment placement i (see Section 5.3.1) and reserving ductwork space early in the !
design process. Proximity of the following should be carefully ;
considered when placing equipment to minimize the amount of j required ductwork: t
(
- Proximity to Outside Air Sources j
- Proximity to Duct Shafts and Plenums
- Proximity to the Unit Vent Shaft ;
- Proximity to Areas Served by HVAC System i
- Orientation of Fans and AHUs to Inlet and Outlet Ductwork f i
4.4 ELECTRICAL CABLE TRAYS /CONDUTT !
I 4.4.1 SYSTEM REQUIREMENTS ;
i 4.4.1.1 System Functions l I
Consideration should be given to the function of the ' electric _ power ;
system being designed. The function of the electric power system '
establishes the basis for the arrangement of the systems within the 'j plant. The on-site power distribution systems should be arranged- -
0 according to the following:
- Electrical power distribution systems feeding non-safety ,
related loads required exclusively for unit operation [
t
- Electrical power distribution systems supplying power to l permanent non-safety loads (i.e., non-safety loads that, 6 due tc their specific functions are generally required to !
remail operational at all times or when the unit is shut down)
- Electrical power distribution systems -feeding safety- l related (Class 1E) loads i 4.4.1.2. Eculoment Selection The selection of electrical equipment should be carefully l considered for impact on the overall design of. electric - power ;
distribution systems. The impact of the following should be [
considered: l Class lE/Non-Class 1E ]
- Voltage j t
DRAFT .4-16 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE
- Power Rating
- Control System Requirements 4.4.1.3 Environmental Recuirements Environmental requirements for electrical systems may influence the design of electrical distribution systems. The following categories should be considered during the design process to determine their impact on the design:
- Temperature
- Humidity
- Radiok 'ivity
- Hazardous Environment
- Corrosive Environment
- Non-combustible Materials
- Inside Environment
- Outside Environment
- Seismic Requirements Safety-related electrical components should be designed and qualified as Class 1E, for the environmental conditions and duty cycles specified for the operation of the plant safety systems.
4.4.1.4 Separation Recuirements .
4.4.1.4,1 Physical Separation The features, configuration, and divisional separation of the safety-related AC and DC power distribution systems should be integrated with the building design to enhance the plant capability for hazard protection.
4.4.1.4.1.1 Fire Protection The arrangement of the electrical distribution systems, both safety-related and non-safety related , should be such that safe shutdown can be achieved with all equipment in any one fire area rendered inoperable by fire, smoke, hot gases, or fire suppressant.
The plant Permanent Non-safety buses and the Alternate AC (AAC) source shall be located in different buildings from the Class 1E 4160 V Safety buses and Emergency Diesel Generators (EDGs). Thus, they will be physically separated into different fire areas.
Special attention should be given to the location of safety and non-safety' buses and the routing of cables. Safety Class 1E DRAFT 4-17 July 25, 1992
SYSTEN 80+" DESIJN CERTIFICATION DISTRIEUTION SYSTCMS DESIGN GUIDE ;
divisional cables and Permanent Non-safety bus cables shall be fully separated by fire barriers. Further, the cables within a ;
Class 1E division for each bus shall be separated within the i division, where practical and when it provides a reliability :
improvement. 1 Switchgear rooms containing safety-related equipment should be separated from the remainder of the plant by barriers with the required fire resistance rating. Redundant switchgear safety divisions should be aeparated from each other by barriers with the 1 required fire resistance rating. Equipment in switchgear rooms :
should be located, to the maximum extent practicable, such that there is ac ess on all sides for manual fire suppression.
I Redundant safety-related panels remote from the control complex .
should be separated from each other by barriers having the required I fire resistance rating. Panels providing remote shutdown capabilities should be separated from the control complex by barriers having the required fire resistance rating. Fire barriers should not impede access to safety-related panels.
Safety-related battery rooms should be separated fr.om each other and from other areas of the plant by barriers having the required .
fire resistance rating. DC switchgear and converters should not be '
located in battery rooms.
The power cables to the 4160 V Safety buses from the Permanent Non- !
safety buses and EDG for each shutdown division should be routed so i that they are not all in the same fire area, which could result in a single fire affecting all of the cables.
The EDG and the 'AAC should be designed such that no single fire scenario (fire confined to a single fire area) will result in the loss of both sources.
4.4.1.4.1.2 Flood Protection Einctrical cable and electrical equipment should be designed and ,
routed to be protected from flooding. Typical protection methods ;
included cable routing away from floors, and equipment placement on raised base pads.
L 4.4.1.4.2 Electrical Separation 4.4.1.4.2.1 Segregation of Voltage Levels Cables should be separated and cable trays arranged according to voltage levels foc fire protection and to prevent high energy lines from affecting instrumentation ant control circuits. See section 6.4.1.3.3 for. recommended separation requirements.
DRAFT 4-18 July 25, 1992
SYSTEM M+" DE.9IGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE l
4.4.1.4.2.2 Safety Channels To minimize the possibility of common mode f ailure, cabling for the !
safety channels should be routed separately. However, the cables of different safety functions within one channel may be routed t together.
I The cabling associated with redundant channels of rafety-related circuits should be~ arranged such that a single failur cannot cause I
multiple channel malfunctions or interactions between channels. ;
Safety /Non-safety Related 4.4.1.4.2.3 Safety-related Class 1E and associated electric cabling and sensing lines from sensors should be kept separate from non-safety related !
cabling.
The design of the plant electrical distribution systems should be ,
such that non-safety circuits are not connected to safety circuits or power sources. l The sets of circuits which constitute the divisions of the safety power distribution systems should be physically separated and electrically independent. Independence and separation should be maintained throughout the load groups. No cross-ties should be used between buses or circuits (AC or DC) belonging to different safety divisions.
4.4.1.5 Physical Protection i
Electrical power distribution systems should be reviewed to determine if hazard protection measures are required. If ,
protection is required, the guidelines of Section 4.1.1.7 should be L used to assist in determining the type of hazard (s) which mas influence the system and the general methods of protection commonly ,
used.
Power cables that are part of safety circuits should be installed in duct banks or raceways designed to provide a high level of protection against industrial hazards, long-term degradation, and other potential risks such as fire, missiles, pipe failure, water spray, or earthquakes.
F 4.4.1.6 _Jrterface Pecuirements ,
The systems which supply power to, and the systems which receive power from an electrical power distribution syatem have requirements which influence the design -of the system. The designer should be able to identify the interfacing systems and incorporate the necessary interf ace requirementr. to ensure pr,per, safe, and reliable operation of the electrical power distribution system.
DRAFT 4-19 July 25, 1992
_ _ . __ _ . _ _ . _ _ _ _ _ _ ~ . . . - . _ _ _ . . . . - _ - _ . . . . . . . _ > .
.i SYSTEM 80+* DESIGN CERTIFICATION DISTRIEUTION SYSTEMS DESIGN CUIDE .;
4.4.1.7 Inspection and Testina Recuirements The electrical. power distribution system' design should incorporate the necessary provisions ua test or inspect the system _or components as required.
4.5 REFERENCES
4.5.1 ANSI /ANS-51.1-1983, " Nuclear Safety Criteria for the Design of Stationary Pressurized Water Reactor Plants".
4.5.2 USNRC Regulatory Guide 1.29, " Seismic -Design Classification", Revision 3, September-1978.
4.5.3 ANSI /ANS-3 8. 3--197 7, " Physical Protection for Systems 'and Component.s Important to Safety".
4.5.4 ASME Boiler and Pressure Vessel Code, 1989 Edition.
4.5.5 ASME B31.1-1989 Edition, Power Piping.
1 l
l l
DRAFT 4-20~ July 25, 1992 l
l
SYSTEN 80+" DESIGN CERTIFICATION 4 D :STRIBUTION SYSTEMS DESIGN GUIDE ,
$ l i
l 5.0 DISTRIBUTION SYSTEMS INTERACTION CONSIDERATIONS L 5.1 .GE]NES M i The integrated design process requires _ con.=ideration of-
! interactions between systems and structures. .This process. ensures i that: ,
A. System requirements are not met at_the-expense of other system and structure designs.-
l B. System effects are accounted- for _ in other systems and
) structures. .
( . .
l C. Multiple design requirements.are.provided with a-single -
j feature.
s D. Optimization is achieved in the design-process.
i 5.1.1 RELATIVE ELEVATIONS i . .
{ Generally, HVAC ductwork and cable trays should be located above j piping to protect them from spray and impingement damage due~to-leaks and pipe ruptures, i
- i. 5 .1.' 2 STRUCTURAL INTERACTIONS f-
. Buildings and_ structures.should be used to the extent practical to j meet system requirements such as firs protection, flood protection, i jet impingement protection, missile protection, separation _ of i redundant trains, and structural: support.
) 5.1.2.1 Con nect '.vi t y p
j In- placing system equipment, other- system. connections _and-F . interactions.must.be considered. Equipment should beLlocated to-j minimize the amount of connecting piping /ductwork/ cable while still i meeting other_ syst m requirements such as elevation relationships.
l- The equipment locations and connecting piping /ductwork/ cable _ should j also provide the, segregation features discussed-in'Section 5.1.3.
I =5.1.2.2 Hazard Protection- ,
4 l 5.1.2.2.1- Flood-Protection
- Structural components should be utilized to the- extent possible to -
- provide. flood protection. Walls-and curbs should
- be used wherever. ,
possible . instead of flood doors which hamper maintenance._ The.
!; .. divisio al wall at the-lowest. elevation in the Nuclear Annex (50+0 )
L - elevation) 'contains no ' . doorways or. passages. D i v i s i o n a l w a l l--
l . penetrations are ' minimized and . sealed ' to ensure- flooding in/one -
4 -division does'not affect the other division.
1
[ DRAFT 5-1 July 25, 1992 J A
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SYSTEM 80+* DESIGN CERTIFICATION-DISTRICUTION SYSTEMS. DESIGN-GUIDE 5.1.2.2.2 Fire Protection
~
Similar to_ flood protection, structural components (walls, floors, ceilings, columns) should be utilized to provide spatial. separation and fire barriers. See Section 5.2.7 for. further discussion of fire protection interactions..
5.1.2.2.3 Missile Protection Structural _ components should be utilized wherever possible ' to provide protection from other hazards such_-as missiles,-pipe whip-and jet impingement.
5.1.2.3 Divisional /Ouadrant Seoaration ,
Structural walls should be otilized for divisional separation, 'and in some cases, quadrant separation. This separation prevents pipe-ruptures or other. failures-in one. division / quadrant from affecting redundant equipment in another; division or quadrant.
5.1.2.4 Proximity To succort structures Proximity to support structures (walls, columns,- ceilings, floors) should be considered when ' routing piping /ductwork/ cable tray or-locating equipment. See Section 6.1.6 for . routing methods to achieve this.
5.1.3 SEGREGATION Equipment and piping /ductwork/ cable should be-segregated-in some applications to minimize adverse interactions.
5.1.3.1 Seismic /Non-seismic Seismic _and non-seismic distribution . systems- are- normally.
segregated to the _ maximum extent possible.- This : segregation minimizes the interaction effects that must-be conside' red for-the seismic systems and minimizes the' amount-of non-seismic systems requiring more rigorous analysis. See Sections 6.1. 5.-l. and 6. 2.3. 5 for further routing guidelines and . interaction effects :-of _ non-seismic : piping with - safety-related piping /ductwork/ cable- trays, along with electrical and mechanical equipment.
5.1. 3 . 2 - Radiation Radioactive - piping /ductwork and' components should be segregated from non-radioactive components ' to : minimize personnel radiation exposure and the potential ~ for contamination- spread. Similarly,-
different radiation _ levels'should.be segregated.where pracuical.
i DRAFT 5-2 July 25,f1992
l l
SYSTEM 80+* DESIGN CERTIFICATION l DISTRIBUTION SYSTEMS DESIGN GUIDE ,
l 5.1.3.3 Hich Enercy Linns i
The effects of high energy line breaks should be minimized by segregation of areas containing these lines, thus minimizing-mitigation features required. Existing structural members should be used to the maximum extent practical to protect against the effects of postulated high energy line breaks that are not eliminated by the leak-before-break (LBB) methodology (see Sections
, 7.1.8 and 7.1.9).
5.2 PTPING 5.2.1 EQUIPMENT LOCATIONS 5.2.1.1 Accessibility Equipment must be placed so as to perform its required function, while having the proper elevation relationships and orientation.
Accessibility for maintenance should be provided based on equipment vendor recommendations.
5.2.1.2 Labvrinthe Labyrinth walls should be provided for radioactive components to prevent excessive personnel exposure at doorways or passageways.
Removable wall sections may be required in these labyrinth walls to allow equipment removability (see Section 5.2.1.3) . Labyrinths may also be utilized to provide missile protection.
5.2.1.3 Ecuiement Removal Provisions Equipment pull space should be provided to allow maintenance or replacement of components - over the 60-year design life. Other provisions for equipment removal include:
- Lifting Provisions
- Removal Path
- Removable Wall Sections
- Flanged Equipment Connections 5.2.1.4 Curbs Curbs should be used for containment of liquids around equipment.
Curbs should also be placed around storage tanks with hazardous materials or radioactive liquids to prevent the spread of these materials in the event of a leak or rupture. The height of the curb will depend-on the liquid volume that must be contained and the area inside the curb. Sloped ramps provide easier access insice the curbs for tank replenishment and maintenance. l l
DRAFT 5-3 July 25, 1992 l
l SYSTEM 80+5 DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN CUIDE Curbs may also be used for flooding protection, either to protect equipment from flooding, or to contain the liquid from equipment leakage or failure.
5.2.1.5 Raised Base Plates Raised equipment base plates may be used to protect equipment from flooding by raising the equipment above the flood level. Raised base plates are not necessarily used in conjunction with curbing, however, if curbing is also used, the interaction of the curbing should also be considered.
5.2.1.6 Elevation Relationshios 5.2.1.6.1 Net Positive Suction Head Pump net positive suction head (NPSH) requirements should be accounted for in the placement of equipment by providing the necessary elevation relationships. The friction loss in the pump suction piping should also be considered since the pressure drop increases the required elevation difference. See Section 6.2.12 for pump suction pipe routing guidelines.
5.2.1.6.2 Drains and Sumps Proper elevation relationships snould be considered when locating and designing gravity drains and sumps. Floor sumps must be designed to avoid excessive weakening of the. floor where they are placed. Physical protection of the sump pumps and discharge piping may be required based on the safety function of the sump pumps.
5.2.1.6.3 Tank Overflow Provisions Tank overflow provisions should be provided for tanks to prevent failure due to overfilling. These provisions may include curbs and drains depending on the contents and discharge locations as discussed above.
5.2.1.7 Electrical Power Provisions Proximity to power supplies and controllers should be considered when locating equipment which is a large electrical load (e . g . ,
pumps).
5.2.2 PIPE SLEEVES Proper pipe sleeve design is vital due to their interaction with buildings and structures. They also should be integrated with the hazard protection provisions and ALARA.
DRAFT 5-4 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 5.2.2.1 Locations 5.2.2.1.1 General A. When locating multiple sleeves in a wall, the center lines of the sleeves should line up, such that concrete rebar interruptions are minimized (see Figure 5.2.2-1).
B. For placement of sleeves in corners, see Section 6.2.3.1.2.C and Figure 6.2.3-4.
C. Spare sleeves should be provided without weakening the structure. That is, Items A and B above should be followed. Spares should be lined up with sleeves located for specific pipes. .
D. Sleeves should be located to accommodate only one pipe each.
E. For information regarding sleeve locations for radiation shielding considerations, see Section 6.2.4.3..
F. Sleeves should be located to allow adequate space so that fittings need not be located within or close to a sleeve.
See Section 6.1.3.2.B.
G. In determining sleeve locations and piping locations, consideration must be given to accessibility and maintenance access aisles.
H. Sleeves and piping should be designed to minimize the possibility of having a fitting in a sleeve (see Section 6.1.3.2.B).
I. Sleeves and piping should be located to - provide some flexibility and adjustment to account for thermal growth and construction tolerances. See Section 6.2.5.3.1.1 and Section 6.2.5.3.1.2.
5.2.2.1.2 Core Drill Since core drills are costl and can weaken the structure, efforts should be made to find feasible alternatives t, drilling such as using an existing spare sleeve or routing pipe to an available sleeve in a nearby area. If no alternatives are practical and a core drill is necessary, the above general requirements are applicable along with the following special considerations:
A. The core drill area should be free of embedded obstacles such as piping, electrical conduit, and steel plates.
DRAFT 5-5 July 25, 1992
. -- . ~ _ - _ . .
i i
-SYSTEMT80+5 DESIGN CERTIFICATION-
~
DISTRIBUTION-SYSTEMS-DESIGN GUIDE.
FIGURE 5.2.2 Pipe Sleeve-Confiourations
-i i
PREFERRED (+ l SLEEVE -!
CONFIGURATION ;
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DRAFT 6 July 25, 1992 li
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SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE B. A 3-inch minimum clearance should be provided at the core drill location to provide for drilling machine access.
5.2.2.2 Sleeve Conficurations i
A. If a sleeve passes through a wall that is a fire wall or necessary for flood protection, a projection should be lef t to allow a boot to be attached. A minimum projection of 2 inches is recommended (see Figure 5.2.2-2 and Section 5.2.7.5.1).
B. If a sleeve passes through a wall that is not a fire wall or other barrier necessary for flood protection, it should
'~
1 be constructed flush with the wall.
C. Special sleeve configurations such as ovals should be avoided where possible because of additional fabrication requirements. Generally, it is better to use a larger sleeve than to use a special configuration, except where OSHA safety requirements restrict the sleeve size (i.e.,
floor penetrations). See Figuro 5.2.2-3.
D. If a sleeve passes through a floor, a projection should be
> left as specified in Section 5.2.2.2.A above.
5.2.2.3 Inspection Accessibility Fittings and other components requiring inspection should be
~
minimized within sleeves. However, if components require l
inspections within sleeves, provisions should be provided for these
. inspections (see Section 6.2 6. 8.2) .
5.2.2.4 Sizine i
Sizing of sleeves requires consideration of thermal growth, insulation and tolerances. Generally a 1" minimum clear space between the outer surface of the piping (including insulation) and the inside of the sleeve is recommended.
5.2.2.4.1 Insulation When the outer diameter of the insulation has been determined, a sleeve should be chosen' which allows a minimum of 1" clearance between the outside of the insulation and the inside of the pipe sleeve.
When insulation is either not required or the thickness is not known, the following method may be used:
A. Low Temperature Piping (Design temperature less than or equal to 200*F) - Increase the sleeve size by two nominal ;
pipe sizes. l l
I DRAFT 5-7 July 25, 1992 j 1
SYSTEM'80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE FIGURE 5.2.2-2 Boot Seal r~.
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l DRAFT 5-8 July 25, 1992
. . . . . - - . . - . - . ~ - . -
i SYSSEN 80+" DESIGN CERTIFICATION DISTRIBUTION' SYSTEMS DESIGN GUIDE-
.t
. FIGURE 5.2.2-3 4
' Oval Sleeve Conficuration 1
b REQUIRED OVAL
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i NON-PREFERRED 5 July 25, 1992-DRAFT
. . . . . . . ....,;_.._.a_..-.._..; ,.-, m -. . . _ _ . . __.~..~ ,,. .-.. . . . _ . . _ , __ . . . _ , -
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE l
B. High Temperature Piping (Design temperature greater than 200*F) -
Increase the sleeve size by three nominal pipe sizes. l, Examples: :
- 1. 2" pipe, design temperature = 150*F m- 6"Isleeve !
required
- 2. 2" pipe, design temperature = 300*F = 8" sleeve _.
required !
5.2.2.4.2 Tolerances There are several tolerances uhich apply when specifying sleeves or :
designing pipe chrougn sleeves and _ these tolerances .can accumulate i such that erected piping cannot go through- its intended sleeve- .j properly, i This can be avoided by specifying sleeves-which are sufficiently [
larger than the intended pipe. ;
In special cases,.. strict erection tolerances may-be imposed _upon construction. Tolerances less than - those' specified - on plant 1;
tolerance drawings-should only be_used as-a-last-resort to assure i critical piping can be installed properly. _;
5.2.2.4.3 Excessively Large Sleeves At times, the sizing method above can result in excessively large ;
sleeves. In some cases it may be better_to reduce-insulation-in !
sleeves - (e .g. , anti-sweat, cooling water insulation). A trade-off l is necessary because of possible compromises in structural strength or number of sleeves. For example,-when' sleeves are large.their j number should be kept to a minimum, and - when : sleeves are small- :
their number may be larger. ] !
Walls can support their-intended structuraliloads with'a-limited -
area allotted for ' sleeves. If the sleeve -information is z known ,
prior to structural design,- walls can be designed to allow- for'.many ;
'large sleeves. Cost for-the structure,--however, will' increase as_ ;
lthe number and size of the sleeves increase.
J i
5.2.2.5- Soecifications j Only standard-pipe sizes should be specified for sleeves,. since- I sleeves are made from pipe. ;
5.2.3 FLOODING PROTECTION Flooding protection- should be- provided to prevent postulated -S flooding sources from preventing required safety functions. For DRAFT 5-10 July 25, 1992 i I +
i i
( .
r
]
~
SYSTEN 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN-GUIDE general flood protection guidelines, see Section 5.1.2.2.1.
i Potential flooding sources include:
i
-+ Tanks I
- Fire Protection Piping
- Moderate Energy Piping Note that potential water spray damage from pipe ruptures in high
- energy lines should be enveloped by jet impingement interactions, i
5.2.3.1 Areas of Interaction
{
l The following guidelines should be used to' evaluate the possibility of nuclear safety-related components being sprayed by water.
i
- 5.2.3.1.1 Moderate Energy Pipe Ruptures I'
Water spray can result from (postulated) pipe ruptures in moderate i energy piping. . Water spray (a direct consequence of the fluid i emitting from a pipey rupture) should-be considered 1only as1the i physical wetting of a component without pressure effects. Water
- spray should be assumed to occur as a conatant_ area jet (i.e., no j jet expansion assumed).
5.2.3.1.2 Inadvertent Actuation of Fire' Protection System Inadvertent actuation of the fire protection system in any.given
! area has the potential for causing water spray interactions and i should Je considered, i
! 5.2.3.1.3 Inadvertent Actuation of-Containment Spray l
l Inadvertent actuation of containment spray in containment has the potential for causing water spray interactions and should be considered.
l
- 5.2.3.2 Evaluation of Water Sorav Effects j -
A review of-water spray effects is_ required to determine if there are any nuclear safety-related components (i.e., equip 9ent, instrumentation, electrical equipment) _ within the-general rsating area which might be damaged by the water spray.
i i- 5.2.3.2.1 Damage Assessment
$ 5.2.3.2.1.1 Equipment.
l_ Safety-related electrical components such as pump motors, motor l
control centers, and switchgear should be assumed incapable of 3
performing their required safety function upon being sprayed by water.
I 4
DRAFT 5-11 July.25, 1992 i
- , ., - .. . .. . - - ,. _ . ~ ,. . - . . - - - - . . , . . . . . , _ . . . . ~ . . , . .
SYSTEN 80+* DESIGN CERTIIICATION DISTRIEUTION SYSTEMS DESIGN GUIDE 5.2.3.2.1.2 Instrumentation Water spray should not preclude the ability of instrumentation to initiate and complete any required safety function. A loss of redundancy is permissible only if, after assuming c single active failure of any component, the safety function of the instrumentation can still be completed.
5.2.3.2.1.3 Valves Nuclear safety-related valves with electrical operators should be assumed to be incapable of performing their intended function upon being sprayed by water unless the valve operators are qualified for water spray. Specific valve operator qualifications should be checked for water spray qualifications.
5.2.3.3 Floodina Prevention / Protection Structural components should b i used to the maximum extent possible for flooding protection. Following are typical methods of flooding prevention / protection:
- Division / Quadrant Separation
~
Pipe Routing
- Equipment Locations Sump Pump Redundancy
- Sump Hi-Level Alarms 5.2.3.4 Other Floodina Prevention / Protection Methods If adverse interactions cannot be resolved by rerouting the pipe or relocating the equipment as discussed above, one of the following methods should be used to show protection.
5.2.3.4.1 Component Qualification Safety-related components which are designed such that they are not ,
affected by water spray need not be further protected from water spray.
5.2.3.4.2 Spray Shields .
Spray shields may be used for situations where pipe rerouting or relocation of safety-related equipment is not possible.
5.2.3.5 Floor Drains Floor drains should be adequately sized to drain spray from fire protection nozzles to prevent area flooding.
i l
l DRAFT 5-12 July 25, 1992 l
~.
l
- - SYSTEM 80+* DESIGN-CERTIFICATION l = DISTRIBUTION SYSTEMS-DESIGN GUIDE i
5.2.3.6 Floodina Isolation
- f. Structural members should be used to the maximum extent'possible l- for flooding-isolation. Other methods include:
-
- Flood Doors l
- Curbs
- Sump Pumps 1
EMBEDDED PIPING-5.2.4 The location of_the interface point between embedded and exposed i portions of piping should allow for easy fit up to the matcl.ing
! exposed piping. Generally, a minimum of 6" is needed (See Figure j 5.2.4-1),
i
- . 5.2.4.1 Picina/ Concrete Interaction 1
Interaction of embedded piping and- the concrete should be
. considered based on ACI 318, " Building Code . Requirements ' for l Reinforced Concrete". Parameters to consider include:
- Temperature
- Thermal Expansion l
- Pressure j
- Material 5
- Seismic Interaction 1
l 5.2.4.2 Embedded Drains 4
! The following are suggested practices for_the designLof-embedded j drains:
A. Minimize the_ length of the run for drains.
B. Minimize the number of fittings used in routing drains.
f C. Avoid low points and dead' legs.
D. Butt welds ~should be used in lieu of socket welds,
~
J E. Eccentric reducers with the flat side on the bottom are-more - desirable fittings than concentric reducers. If there is a possibility of choked flow, and crud build-up -
3 is_unlikely, eccentric _ reducers with a flat side-on top
_are' acceptable.
F. Clean-outs should be placed every twenty feet, where possible.
DRAFT 5-13 July 25, 1992
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FLOOli Allow' Minimum.6" Projection to' Interface Point July 25, 1992L .;
5-14 DRAFT-I
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- SYSTEM 80+" DESIGN CERTIFIC?ATION j' -DISTRIBUTION SYSTEMS DESIGN GUIDE G. Pipe should be sloped 1/8" per foot in the direction of j- flow, where possible.
H. Straight-in approach- and abrupt- changes of- direction ,
!' should be avoided (see Figures 5. 2. 4-2 and 5.2. 4-3) .
This design approach will minimize potential hot spots . and; crud -
traps from forming in the drain-lines in potentially-radioactive piping.
i 5.2.5 BURIED PIPING ,
I 5.2.5.1 Freeze Protection Piping and equipment located in-potential freeze zones should be- '
considered for insulttion and possibly heat tracing.
i i- The effects of freezing temperatures o n -- p i p e , equipmen , and' i- instruments should be considered during the design phase. There are several methods which may be utilized to prevent freezing.
Recommended methods of freeze protection are listed below:
A. Reroute to an Interior Area B. Heat Tracing C. Insulation I
D. Localized Heating From a piping design standpoint, method A or C is preferable. If-method B is to be used, the electrical impact must be considered.
If method D is to be used, the HVAC impact should be considered.
5.2.5.2 Insoection and Access Recuirements j Access for required inspections lshould ~ be = provided, usually by accessible pipe. trenches or pits.
Trenches should also be considered- to provide access for _ piping which could require--
replacement over the life of the plant.
5.2.5.3 Physical Protection Physical protection should be provided;for buried piping. Usually freeze protection also:provides physical protection, either by an enclosed pipe trench or burial 'below the . freeze line.
Administrative requirements should be -implemented to prevent damage due to excavation.
DRAFT 5-15 July 25, 1992
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SYSTEN 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE FIGURE 5.2.4-2 t
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Floor Drain Conficuration I
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. DRAFT 5-16 July 25,-1992 l
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SYSTEM i80+* DESIG21: CERTIFICATION DISTRIOUTION SYSTEMS DESIGN GUIDE i
l FIGURE 5.2.4-3 3
, Ecuig ent Orain Confieuration i 1
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! PREFERRED EOUIPMENT DRAIN STUB i Saddle-in or Saddle-on preferred and less- '
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5.2.5.4 Seismic Interaction With Structures
{ Seismic interaction of buried piping and structures is described in j CESSAR-DC, Section 3.7.3.12.1.
L l 5.2.6 EXPOSED PIPING 5.2.6.1 Freeze Protection Exposed piping, especially instrument lines.- are . susceptible - to
- freezing damage and should be avoided, especially in cold climates.
If : exposure is not avoidable, the freeze protections methods 7
discussed in Section 5.2.5.l'should_be considered depending on the fluid medium and winter. climate conditions,.
j
!-- 5.2.6.2 Physical Protection 1
4 Exposed piping is also susceptible to physical damage and should be-Where_not- avoidable,- appropriate-
! avoided' where. possible.
j protection should be provided. -Protection from postulated hazards-must be shown by-analysis for safety-related piping.
[
4 DRAFT 5 July.25, 1992 r
iSYSTEN'SO+5 DESIGN CERTIFICATION DISTRIEUTION_ SYSTEMS. DESIGN GUIDE 5.2.7 FIRE PROTECTION-Fire protection-is required throughout the' plant, but adds special:
interactions that should be-considered for all piping systems.
-5.2.7.1 Plant Layout Plant ' layouts -should: be . arranged to isolate safety-reJ ated.- :
equipment from unacceptable fire hazards and separate redundant -
safety-related systems from each other so that both are not subject to damage from a single fire hazard.
5.2.7.2 Fire' Protection Sorinkler System 'f The location of process piping in plant areas served by sprinklert:
should allow free dispersion of the sprinkler liquid. Routing- :
piping close to sprinkler heads should be avoided. -
f 5.2.7.3 Fire Protection Valves Fire protection valves should De-located away from the areas _they( >
service. The - nature 'of these valves require quick and ~ easy; :
accessibility at - all times. Therefore, process piping-routed in' 4 these areas should facilitate accessibility.- !
5.2.7.4 Hose Reel Cabinets r
i Hose reel cabinets should be easily accessible. All process piping - ;
should be routed to accommodate this. j 5.2.7.5 Fire Seals f Fire seals are-used to seal penetrations through fire._ walls. .Two j appropriate methods for saaling wall sleeves are described below: -j u
5.2.7.5.1 Boot Seal !
A boot seal-is an approved fire barrier. - The seal is made from a i flexible- fire resistant material Land looks somewhatl-.like- a !
concentric reducer. !
1 The use of a boot seal -normally . requires that the wall sleeve project approximately 2 inches from the wall,, thus allowing one end-of the seal to be clamped.to the sleeve.and the othercend to:be- !
clamped to the pipe passing through the sleeve. . Note'that~there- ;
i are methods of applying a boot seal to sleeves which ara flush'with l the-wall. j.
, A boot seal should be specified vfor. use ; in situr.:. ions where1 the j l piping- passing through the sleeve is~ subject-to thermal movements- ;
l which cannot- be- tolerated- by fire seal- foam (see Section- :
5.2.7.5.2). j DRAFT 5-18 July 25,;1992 [
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i SYSTEM-80+" DESIGN CERTIFICATION DISTRIOUTION-SYSTEMS DESIGN GUIDE
' 5.2.7.5.2 Fire Seal Foam i '
l Fire seal foam is an-approved fire barrier which-is.used to seal-fire wall penetrations. Fire seal foam-is applied in a liquid.
state and-then cures to a foam-like material.
Fire se;l foam is an effective fire seal, however, its application
- is governed by the geometry of the piping in the sleeve and'the-l thermal movement of the piping. The geometry restrictions are addressed in Section S.2.7.8.1.A, B, and , C while the thermal l movement _ restrictions are addressed in Section 5.2.7.8.2. .
! 5.2.7.6 Drains i
3 Floor drains, sized to remove expected fire fighting '.iquids plus liquids- from cther sources (e .g. , tanks) , should be provided'in-those areas where water suppression systems are:inctalled. Drains
! should also be provided in other areas where hand hose lines could i be used if such fire fighting water. could cause unacceptable damage -
to equipment.
5.2.7.7 Flushina and Testina Provisions Provisions should be provided for flushing ' and testing of: fire-j protection piping.
5.2.7.8 Fir _e Barrier Penetrations f
f All piping - penetrations l'n f i r e barrier walls should -be - sealed
- appropriately.
1 5.2.7.8.1 Design Considerations
! Fire barrier penetration design considerations are'as follows:
{ A. Multiple pipes and cables through the same sleeve'should
[ -be avoided.
B. The annular-space should be_no.more than -'" 4 - if fire seal i foam is to be used.-
C. The maximum normal sleeve size should be 14". Sleeves larger than 14" should project-from the_ wall at least_2" to: allow boot seal installation.
i
! D. Pipes penetrating a steel stud drywall 1 should have a space envelope of at least 2" around the 0.D. of the pipe and 8"-
from the wall. This allows for boot installation' and should be checked -for interferences (e.g.,fhangers) .
l i
DRAFT 5-19 July 25, 1992 l
3
- SYSTEM 80+" DESIGN CERTIFICATION
- DISTRIEUTION-SYSTEMS DESIGN GUIDE
~
E. Fire wall penetrations by' non-metallic pipingi (e.g., PVC) should be changed to steel pipe for a distance of at least 5 feet on either side of the wall.
5.2.7.8.2 Piping Penetrations _ Subject'To Movement Foam fire wall sealant can absorb 4"' of movement per 2" of - foam radial thickness. ' Thickness is measured from the pipe OD to the sleeve ID. Movements greater than that allowed for foam require a boot seal.or another acceptable fire. seal.
5.2.7.9' Other Fire Protection Interaction Considerations 5.2.7.9.1 Fire Hazard Prevention Provision should be made to preclude fire , hazards -for' piping ;
carrying petroleum-based or other_ potential = flammable materials. !
i 5.2.7.9.2 Explosion Prevention {
Provision should be made to preclude explos' ion hazarde for piping !
carrying combustible gases such as hydrogen. t i
5.2.7.9.3 Personnel Protection-From Exposure to Incapacitating. [
Gases Incapacitating gas protection, such. as chlorine gas ~ protection for [
the Control Room, should be provided for where warranted. !
I 5.2.8 PIPING INTERACTION WITH ELECTRICAL EQUIPMENT / CABLE: ,
5.2.8.1 Electrical Equioment Interaction-f 5.2.8.1.1 Piping Guidelines :
Piping should be designed and routed so as to not adversely impact i electrical equipment operation . or cable operability. Piping !
guidelines include the following: !
A. Piping should not be routed above-electrical equipment to j avoid water and/or collision damage in the event of _a pipe ;
rupture. .;
B. Piping.should not interfere'with electrical erbinet door- -;
swing space or enter in the' cabinet mainter.ance - access 1 area. -!
t C. Piping should not be routed close to electrical equipment. l A typical minimum distance of 30"'to the side and below- .!
electrical equipment should be maintained.
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DRAFT 5-20 July 25, 1992 ;
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SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 4
5.2.8.1.2 Guideline Compromises Wherever possible, the guidelinos listed in Section 5.0.8.1.1
, should be applied. The following compromises may be made, though, for situations where these guidelines are impractical:
i A. Moderate energy or seismically designed high energy piping
- may be routed above non-safety related electrical equipment if only straight pipe is involved (i.e., no in-
- line components such as valves or instruments) and anti-sweat insulation is installed.
B. A minimum clearance of 30" below or to the side of electrical equipment is desired but may be compromised, taking into account the characteristics of the pipe such as:
, 1. Type of fluid in pipe.
- 2. Temperature of fluid in pipe.
l
- 3. Seismic /non-seismic design of pipe and/or electrical ecpipment.
- 4. Whether or not the electrical equipment is safety-related,
- 5. Other pipe or electrical equipment characteristics which influence accident damage possibility.
5.2.L. Cable Trav Interaction Where a single pipe crosses perpendicular to a cable tray, a minimum vertical clearance of 6 inches should always be maintained between the piping and the cable tray. Wherever possible, use the spacing requirements of Table 6.2.6-1, 5.2.8.3 Other Picina Interaction Considerations A. Piping should not be located in, above, or below electrical shafts.
B. High energy piping should not be~ routed in the Control Complex, Electrical venetration Rooms, Vital Instrumentation and Electrical Rooms, or Remote Shutdown Panel Rooms to keep potential adverse interactions to a minimum. See Section-7.1.8.1.1 fcr a description of high energy piping.
C. Moderate energy piping should not be routed in the Control Room to prevent potential flooding interactions.
DRAFT 5-21 July 25, 1992
~
CYSTEM 80+" DESIGN CERTIFICATION-DISTRIEUTION SYSTEMS DESIGN GUIDE 5.2.8.4 Seoaration of Electrical Components Piping of one train connecting to electr3 cal . equipment for control purposes - should be routed so as to comply with the electrical-separation of redundant components-requiremant. Redundant circuits should be separated three . feet- horizontally and-- five feet vertically in_the General Plant Area and one foot hcrizontally and three feet vertically for the_ Control Complex Area.
Electrical requirements dictate that ~ there should be a minimum separation distance between redundant Class lE and Non-Class lE circuits and equipment. This separation distance-must be free of interposing structures, equipment, or materials which could aid in the propagation of fire or could-disable Class lE circuits. The piping layout should not interfere with-ths separation distance. -
5.2.8.5 Fiber Ootic Cable Interaction Radiation effects should be considered in potential fiber optic cable applications. Where the radiation levels preclude the use of fiber optic cable,-coaxial cable should be used.
5.2.9 PIPING INTERACTION WITH HVAC EQUIPMENT /DUCTWORK 5.2.9.1 General General HVAC ductwork/ piping interaction considerations are contained in Section 5.1. In addition, . piping should-not be routed through ductwork due to potential adverse-interactions.
5.2.9.2 Access to Dampers and Other HVAC Eculoment Access should be provided to HVAC dampers, fans,- and filter units so as to facilitate maintenance-activities.
L 5.2.10 POSTULATED PIPE BREAKS l -
l Postulated pipe breaks, their interactions, =and analysis requirements.are discussed _in Section 7.1.8',
5.3 HVAC DUCTWORK
'5.3.1 HVAC EQUIPMENT LOCATIONS L
5.3.1.1 Accessibility L Equipment must be placed t'o _ perform its. required function, and allow access for _ operation and - maintenance . Accessibility for maintenance should be- provided based on equipment vendor recommendations and operational experience.
DRAFT 5-22 July 25, 1992
k SYSTEM 80+" DESIGN CERTIFICATION i -DISTRIEUTION. SYSTEMS-DESIGN. GUIDE J 5.3.1.2 Soace Limitations l-
' HVAC equipment:- (fras, filters, AHUs)_ takes up a significant amount
~
i of: space and must-be: located accordingly. Allotting equipment
- space _early in the design process should ensure adequate space and
- allow the ductwork--length to be minimized.
j: 5.3.1.3 Eculement-Removal Provisions t
Equipment ' pull space _should be provided,to allow maintenance or replacement of components over the 60-year design life. Other
, provisions for equipment removal include:
- Lifting Provii ? ons s
- Removal Path ;
4
- Removable Wall Sections
[
- Flanged Connections
)
- Access for Filter Changeout
- Removal and Laydown Space for.Ductwork Sections '
f j 5.3.1.4 ALARA i
Due to the potential radioactivity of. some HVAC ' equipment (e.g.,
j-- filter trains), ALARA must be considered in the design. Equipment enclosure should be considered along with provisions for changing
!j potentially radioactive filters.
i 1 5.3.1.5 Electrical Power Provisions f Proximity to power supplies and controllers should be considered j when locating egyipment which is a large electrical load - - (e .g. ,
- fans).
! 5.3.1.6 Chilled Water j
i Chilled water _ pipe routing -should be - considered. when placing equipment such as recirculating air handling units.
! 5.3.1.7 Drain Provisions
- Drain provisions shouldLbe considered for equipment such as fans, I cooling. coils, moisture-separators,. and water deluge systems in air cleaning units. . The radioactivity potential of the drain water a
i must also be considered.
4 l
1 N
i DRAFT 5-23 July 25, 1992_ _
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SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN CUIDE 5.3.2 STRUCTURAL INTERFACE 5.3.2.1 Wall / Floor Openinas The strength of floors and walls around ductwork openings should be carefully considered due to the required size of t.he penetrations.
5.3.2.2 Structural Leadine The structure must be adequate to support the HVAC equipment loading along with supports for the ductwork and in-line components. See Section 7.2 for HVAC ductwork analysis.
~
5.3.2.3 Fire Protection Seals should be provided at duct penetrations (walls, floors)' of fire barriers. Fire seals and fire dampers should be used to ensure that the penetration does not degrade the fire barrier below required levels (see Section 4.3,1.10) .
Vertical duct shafts and plenums shculd be reviewed carefully, since stack effect can occur if adequate fire barriers are not provided at floor elevations.
3 5.3.3 MECHANICAL INTERFACE t 5.3.3.1 Pipine Interface HVAC ductwork should be routed above piping where possible to prevent ductwork damage due to pipe leakage or rupture. Routing of v pipe through ductwork should be avoided.
, 5.3.3.2 Electrical Cable Trav/ Conduit Interface Ductwork and cable trays will usually be in the same vicinity in the upper room elevations. Proper segregation (seismic, non-seismic) should minimize adverse interactions between HVAC ductwork and cable trays (see Section 5.1.3) .
l l 5.4 ELECTRICAL CABLE TRAYS / CONDUIT 5.4.1 ELECTRICAL EQUIPMENT LOCATION I
5.4.1.1 Joace Allocation Space for electrical equipment should be allocated in the plant general arrangement during the design phase to ensure adequate room exists for electrical panels, cabinets, switchgear, and other electrical equipment. In addition, space for cable trays should be ;
reserved on the plant arrangements as these electrical items tend to require a significant amount of space.
DRAFT 5-24 July 25, 1992 b
SYSTEN 80+" DESIGN' CERTIFICATION DISTRIEUTION. SYSTEMS DESIGN GUIDE 5.4.1.2 Soace Limitations Building space limitations can result in equipment placement and routing constraints. Adequate space should be provided by reviewing other locations, reorienting the equipment, or building arrangement-changes.
5.4.1.3 gennectivity Electrical equipment should be-located so-as to reduce the amount of cabling required, thus reducing the amount of cable trays and conduit within the plant.
5.4.1.4 Accessibility Electrical equipment should be located considering accessibili'ty.
Sufficient clearance should ba provided for cabinet- door swing space, electrical panel access and removal, and junction ' box access.
5.4.1.4.1 Maintenance Provisions Accessibility to electrical equipment and components which may require maintenance should be provided.
5.4.1.4.2 Equipment Removal Provisions The electrical power systems should be designed for a 60-year operating life without replacement of major components or _ cabling.
However, the design of the systems and the building arrangement should permit such replacement, if required.
5.4.2 STRUCTURAL INTERACTION 5.4.2.1 Wall / Floor Openinos The strength of-floors and walls ;~ound cable-openings should be considered.
5.3.2.2 Structural Loadina The structure must be adequate to support the electrical equipment loading along with supports for the cable trays and conduit. See Section 7.3 for electrical cable tray and conduit analysis.
5.4.2.3 Succort/ Restraints A seismically qualified cable support system shall be provided for all raceways containing Class 1E cables (see Section 7.3).
DRAFT 5-25 July.25, 1992-
SYSTEM 80+8 DESIGN CERTIFICATION-DISTRIEUTION-SYSTEMS DESIGN GUIDE 5-4.2.4
. Ecuicment Bases Equipment bases _ shall be provided- for _ electrical equipment - and -
components in areas which areasubject to becoming wet.
-5.4.2.5 Embedded Conduit Embedded conduit- locations should be considered to take into account rebar,-_ openings, and other-interferences.
5.4.2.6 Groundino System The grounding system arrangement should be considered-for eciuipment placement and cable routing.
5.4.3 MECHANICAL INTERACTION 5.4.3.1 Pirina Interaction Whenever possible, non-safety related electrical cable trays should not be routed above or adjacent to- safety-related piping such thac seismic interaction is-possible.
5.4.3.1.1 Temperature Considerations Multi-level cable tray systems should provide,_as a minimum, one-foot, four-inch vertical spaces between the bottom of the_ upper tray and the top of the lower tray,.and;two feet of horizontal space between adjacent trays'.
Cable tray and. conduit should be located a safe distance from high
~
temperature piping systems to_ preclude _the necessity of reducing the cable ampacity as a result of increased ambient temperature'.
5.4.3.1.2 Accessibility for Maintenance and Testing l Access should be provided_to electrical equipment to' facilitate
- maintenance. activities and1 testing. Cabinet door' swing should be considered as well as other' test connections.
~
5.5 REFERENCES
5.5.1 ACI 318-89, " Building Code' Requirements for Reinforced Concrete".
5.5.2 ASME B31.1-1989 Edition,_ Power Piping.
5.5.3 CESSAR Design Certification, System 80+ Standard Design,_
l- AmendmentI.
DRAFT 5-26 July 25, 1992
i
-SYSTEM 80+* DESIGN CERTIFICATION-DISTRIEUTION' SYSTEMS DESIGN GUIDE t
6.0 DISTRIBUTION SYSTsrQ P;UTING GUIDELINES 6.1 GENERAL i 6.1.1 ' PIPING /DUCTWORK/ CABLE TRAY RELATIVE ELEVATIONS l Piping should generally be routed below HVAC ductwork and cable . I trays to prot 6ct ' the ductwork and cable trays from spray and ;
impingement damage due to leakage and postulated pipe ruptures.
6.1.2 DIVISIONAL AND QUADRANT SEPARATION l l
I Structural walls should be utilized _for divisional separation in the Nuclear Island. Quadrant-separation.should be= maintained for ECCS components in the Reactor Building subsphere. This separation !
is- intended . to prevent pipe ruptures or other f ailures ,in ~one i division / quadrant ~ from 'affecting redundant equipment in another ,
division and/or quadrant. l 6.1.3 STANDARD COMPONENTS [
t Use of standard components should be maximized for all distribution !
systems. Standard components are more interchangeable, more !
readily available, and less costly. !
6.1.3.1 Picino l .
-i
- For interchangeability_ and ease of procurement, standard pipe sizes ;
and materials should be utilized wherever possible.
l 6.1.3.2 Fittinas A. Standard fittings should be 'used - in -_ all- possible l applications. Non-standard fittings ~as'shown in Figure ;
6.1.3-1-should be avoidec... !
B. Fittings in sleeves hinder access for welding- and ;
-inspections. Fittings and welds in sleeves should be j avoided. ,
-)
i C. - Branch . fittings : should be checked for compatibility. and !
compliance with piping and installation' specifications.
~
6.1.3.3 Valves Manual and control valves, as well;as valve operators, should:be standardized-to the maximum extent possible.
t l
. DRAFT 6-1 July 25, 1992 P
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SYSTEM 800 5 DESIGH CERTIFICATZON DISTRZBUTION SYSTEMS DESIGH GUIDE FIGURE 6.1.3-1 Non-standard Fittinos i
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90 STREET ELBOW MITERED 90 ELBOW OR 90 SHORT RADIUS ELBOW I
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90 LONG RADIUS NOZZLE WELD REDUCING ELBOW f'1 1 NS M ,q- e t -m
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w u._ c_ , _ _ v I I CRbSS SADDLE Use of these non-standard fittings should be avoided.
DRAFT 6-2 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIDUTION SYSTEMS DESIGN GUIDE
.1.
6.1.3.4 Pipe Succort s Standard pipe support desigr.s and materials should be utilized to the maximum extent possible. Optimum envelopes for support dosigns should be developed for use during pipe routing. Support guidelines are described in Section 6.2.3.
6.1.3.5 HVAC Components j Similar to piping, HVAC systems and components should be 4
standardized to the maximum extent possible. HVAC components include ductwork, ductwork supports, fans and dampers. '
i 6.1.3.6 Elgetrical Components Similar to piping and HVAC, electrical components should' bc 1 standardized to the maximum extent possible. Electrical components i include cable, supports, cable trays, conduit, junction boxes and 4
MCCs.
I 6.1.4 CO!1STRUCTABIL7.TY 6.1.4.1 Tolerances Adequate tolerances should be provided in the design to facilitato construction and preclude rework and field change delays.
6.1.4.2 Standard Components Standard components should be utilized to the maximum extent possible (see Section 6.1.3).
6.1.4.3 Accessibility
- 6.1.4.3.1 Clearance Clearances should be provided in the design to allow for '
construction, preservice/ inservice inspection, operation, and maintenance.
6.1.4.3.2 Testing Provisions Testing provisions should be incorporated into the design. Access should be provided for both preservice and inservice testing.
Personnel and testing equipment access should also be considered.
Isolation valves, test connections, and recirculation / bypass lines should be incorporated into the design to preclude abnormal system lineupa.
DRAFT 6-3 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIDUTIC3 SYSTEMS DESIGN GUIDE 6.1.4.4 Interforences Field changes during construction result in significant delays and costs. These problems are best circumvented in the design phase by preventing interferences. Interferences should be precluded by utilizing an integrated 3-D plant model with interference check capability.
6.1.5 SEGREGATION 6.1.5.1 Seismic /Non-seismic To the extent practical, non-seismic and seismic system segments should be segregated to lower the cmount of non-seismic piping requiring seismically analyzed supports (see Section 6.2.3.5).
6.1.5.2 Radicactive/Non-Radicactivo Pi, ping Radioactive piping should be segregated to the extent possible in order to utilize the 1.hielding provided by the structure while maintaining radiation levels within limits imposed during design.
6.1.6 SUPPORTABILITY Distribution systems should be routed to be supportable. The routing guidelines in this section facilitate supportability.
6.1.6.1 Proximity to Support Structures Distribution systems should be routed close to support structures (walls, columns, ceilings, floors). This simplifies support de s i',1s and allows support standardization. Close proximity is especially important near in-line components such as valves, flowmeters and dampers. Valve supportability is discussed in Section 6.2.2. Structural interactions are discussed in Section 5.1.2.
6.1.6.2 Base Plate Provisions Embedded plates should be utilized wherever practical to minimize embedded anchor bolt use. Spare embedded plates should be provided to allow for modifications aver the plant life.
DRAFT 6-4 July 25, 1992 9
SYSTEM 800* DESIGN CERTIFICATION i DISTRIBUTION SYSTEMS DESIGN GUIDE 4
6.2 PIPING l
6.2.1 EQUIPMENT CONSIDERATIONS
, 6.2.1.1 Eauipment Arrancement i
6.2.1.1.1 Accessibility Accessibility for installation, testing, operation, and maintenance of equipment should be provided based on equipment requirements l provided by the vendor and past plant experience.
I Pull Space 6.2.1.1.2 I
Equipment pull space should be provided based in vendor !
requirements. Pull space provisions include equipment and !
equipment module (i.e., tube bundles, pump motors) removability.
6.2.1.1.3 Maintenance Maintenan'.h ;rovisions should be provided, including monorails, jib cranes, r acN~.ble wall sections, hatches, and flanged connections.
4 Orientation and requirements of other equipment in the vicinity should also be considered.
6.2.1.2 Connectino Picinc Recuirements 6.2.1.2.1 Nozzle Loads Equipment nozzle loads should be minimized to be within equipment vendor specifications. If nozzle load limits are not known, conservative nozzle loads may be assumed and verified with vendor specifications. Typical nozzle loads that may be used for these conservative assumptions are listed below in Table 6.2.1-1.
TABLE 6.2.1-1 Typical Allowable Nozzle Loads Service Level Forces (1bs) Moments (In-lbs)
Normal 200 x A 2000 x S Upset 400 x A 4000 x s Faulted 500 x A 5000 x S Where: A = Pipe cross-sectional metal area (in 2)
S = Pipe section modulus (in 3)
DRAFT 6-5 July 25, 1992
SYSTEN 80+"' DESIGN CERTIFICATION DIS 7RICUTION SYSTEMS DESIGN GUIDE 6.2.1.2.2 End Connections End connections should be designed to be compatible with interconnecting piping.
6.2.1.2.3 Heat Tracing Heat tracing is 1 sed for liquid-containing pipelines to prevent the liquid from fre' zing or becoming too viscous. In pipelines 1 containing gases, heat tracing prevents gas components from !
condensing. Piping may be heated by using fluid heating media !
(steam, hot water, ho oil, or Dowtherms), or by electricity. Heat tracing should be minlaized due to the required .naintenance.
Typical heat traced piping applications include borated water lines, and lines subject to freezing during cold weather. Borated water 4ines greater than 2.5% by weig.it require heat tracing to prevent precipitation. Note that for System 80+, the only borated water piping requiring heat tracing should be for CVCS bornn batching due to the RCS boron concentration being less than 2.5%.
6.2.1.2.3.1 Requirements When a piping system requires heat tracing, the designer should take into account the installation and maintenance of the heat tracing system. Guidelines are as follows:
A. In order to minimize the possibility of short-out due to flooding or loss of heat, piping requiring electrical heat tracing should not be located near floors or at low points in the building.
B. Heat traced piping should not be located in high traffic areas where physical damage could occur (e.g, access aisles). If piping must be located in a high traffic area, a minimum clearance of 30 inches should be provided and protective shields should be installed.
C. Heat traced piping should be separated from other piping, j walls, floors, and ceilings, with sufficient space for 4 installation of cables and insulation. Typically, a 12" i minimum clearance is needed. General spacing requirements for ASME Class 1, 2, and 3 piping are given in Section 6.2.6.2.
D. Flange connections should be kept to a minimum to avoid the need for heating cable adders.
i E. When choosing a sleeve for a pipe that is being heat ;
traced, the sleeve should be large enough to accommodate i the heat tracing cables and necessary insulation (see ;
I Section 5.2.3.4).
4 DRAFT 6-6 July 25, 1992
i I l
]
! SYSTEM 00+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE I
j F. Outdoor piping should meet the intent of Section 6.2.1.2.3.1.B and should remain easily accessible from a !
i standpoint of setting and maintaining locally mounted
] temperature controllers.
6.2.1.2.3.2 Steam Tracing Of Pipelines i Heat to piping may be provided by steam pipes either inside or outside the line. Steam jacketing may also be used, but due to its
- high cost, it is employed only for special situations involving j high heating loads. Since steam has a high film heat-tranLlar-
, coefficient, it condenses at constant temperature and flows to the ;
~
4 point of use without pumps. Typically, this_ practice is not used in nuclear plants due to the unavailability of high temparature, .
! superheated steam. In other plants (coal, oil) where high l t temperature, superheated steam is available, this method is rnore ;
i practical.
'I 6.2.1.2.3.3 Electrical Pipe Heating
\
j External heat tracing consists of installing electric heating
- cables in contact with the outer surface of the pipe with stainless steel straps, and thcn applying insulation to the pipe. The most j
i common size cable used is 3/8" OD with an option of 5/8" OD wiring.
- After the wires are connected,- the heat tracing is covered with i aluminum lagging. Heating by electricity to maintain _ temperatures i in pipelines has advantages over steam. These-are
4 A. Heat can be provided with automatic controls.
B. Heating of the pipe is more uniform.
j C. Operating and maintonance cost are lower than steam.
?
}: D. Heating can be applied equally to short and long pipelines.
i Some borated water system use two heat tracing systems. The i primary system can have a temperature setting of 175'F, and the i i secondary system a setting of 160'F. 'The secondary system can be i used as a backup system, or it can.be used as_ an additional heating i system along with the primary system to prevent" crystallization of 2
borated water at higher concentrations.
1 .
j- Note that at boron concentrations less than 2.5% by weight, -
i crystallization does not occur-down to 32*F. -Since the System 80+
maximum boron concentration is 2.5%,: only the borated water _ piping
{ used in the mixing and transfer from the . CVCS batching - tanks requires heat tracing.
l ,
i 1
4
- DRAFT _ 6-7 July 25, 1992 .
I t
i m._ . , . - . . , __ , - , _ _ _c. _ _..-,..~.,__,_______._....-....--.-_._.a_.-,
SYSTEM 80+5 DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE 6.2.1.3 Plowmoters Twenty oipe diameters of straight pipe should be provided upstream, and ten pipe diameters of straight pipe should be provided downstream of flow elements unless otherwise specified by manuf acturer's instructions. The inside diameter should be used for the pipe diameter computation.
6.2.2 VALVES 6.2.2.1 Valve Functions General valve applications and guidelines are stated below.
Specific applications should be researched further, as appropriate.
6.2.2.1.1 Gate Valv<t 6.2.2.1.1.1 Solid Wedge This valve is recommended for lines at ambient temperatures and in line sizes 4 inches and smaller. Thermal differentials and pipe loads can distort critical body interfaces that-the solid wedge cannot adapt to.
Additionally, the solid wedge is not suited for use with power actuators. Changes in operating characteristics of actuators and environmental changes dictato its use to be limited to applications where manual actuation is a.cceptable.
6.2.2.1.1.2 Flex-Wedge and Split. Wedge These are probably the best general purpose gate valves available.
The flexibility of the wedge allows operation over a broader range of conditions. They should not be used in applications that are subject to extreme temperature variations or fast closure. The i limitation on speed of operation is a result of the tendency of the l wedge to lock or bind when closed quickly.
6.2.2.1.1.3 Double Disc The double disc valve is designed to provide tight shut-off and reliable operation in extreme environments. Its free floating disc and parallel seats eliminate the criticality of the seat-disc angles, permit tight sealing under the most adverse temperature and pipe loading conditions, and greatly simplify maintenance. The wedging mechanism allows the valve to be used at temperature extremes and assures reliable opening regardless of closure speed.
This type of valve should be considered whenever one or more of the following conditions are required: (1) the valve must close l quickly, (2) bubble tightness is desired, or (3) air seat leakage testing is required, j DRAFT 6-8 July 25, 1992 l
l
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUID3 6.2.2.1.1.4 Conduit l The conduit gate is a valve that is designed for use in service where an unobstructed flow passage through the seat area is r+equ i red . It has been extensively used in pipeline services where the practice of running " pigs" through the pipeline necessitates j the elimination of any surfaces that they could get hung up on.
Conduit valves are also used in lines where the media is " dirty" and contains particles like rocks or metal chips.
6.2.2.1.2 Globe Valve 1 1
Globe valves are generally t' sed for throttling and shut-of f. When used in throttling applications they should be installed with flow under the seat. The configuration of the disc is such that only the bottom presents a smooth flow profile. The sharp profile of the top of the disc, when exposed to high velocity fluids can cause turbulence. This results in unreliable throttling and possible valve damage.
Globe valves can also be used for shut-off, but.are also unidirectional in this application. In order to obtain a tight seal, the valve should be installed with flow over the disc. With flow under the disc, the actuator has to provide a force equal to the full differential plus an additional amount to provide a sufficient unit load in the seat to achieve a seal. This force must be maintained if the valve is to remain tightly sealed.
With flow over the disc, the pressure acts as the sealing force.
In this situation, the actuator is cequired only to overcome the -
differential pressure force when the valve is operated.
Aside from the different types of discs cupplied, globe valves are also supplied in four different body configurations. They are the Regular (horizontal or pattern), "Y" (wye), Angle, and the Y-Angle (elbow down).
Note that packless globe valves are used as isolation service with flow under the disc. Packless globe valves should not be used for throttling or reversible flow conditions. These valves should also be installed in cjean systems at they are very susceptible to seat damage caused by impurities in the system.
6.2.2.1.2.1 Horizontal Globe This is the most commonly used of the globe valves even though it has the greatest flow resistance.
DRAFT 6-9 July 25, 1992
,, -- ,,,,,,.e. - e,-- -
^
SYSTEM 800 5 DESIGN CF.RTIFICATION DISTRIBUTIO)? SYSTFJLS DESIGN GUIDE 6.2.2.1.2.2 Y-Globe This design is used where throt.tling capability is required but lower flow resistance is desired. The inclined stem angle makes maintenance more difficult than with a horizontal globe.
6.2.2.1.2.3 Angle Globe This design takes advantage of a 90* bend in the - piping and replaces the elbow with a throttling valve. This eliminates extra welds, reduces system pressure drop, and permits the most efficient use of available space. .
6.2.2.1.2.4 Y-Angle Globe This design cabines the installation versatility of the angle valve with the lower pressure drop of the Y-globe. The installation limitations of this type are opposite of those for a regular angle valve.
6.2.2.1.3 Check Valve Check valves differ considerably in their construction and operation from the other groups of valves designed either to stop the flow entirely or to throttle the flow to the degree desired.
There are three basic designs of the check valvet the swing check valve, the lift check valve, and the tilting disc valve.
6.2.2.1.3.1 Swing Check These are the most popular of all check valves since they offer very little resistance to flow when in the wide open position.
They are general',y used in all piping where the pressure drop is of prime importance. Swing check valves are used for handling liquids, and can be installed in vertical (flow up) or horizontal position without impairing their performance. To allow for maintenance, swing check valves 8" and larger should not be installed in ve::tical pipe runs unless horizontal installation is not possible or feasible, or other applications where the reversal of flow is frequent, since this could cause the valve disk to fluctuate rapidly and result in " valve chatter."
6.2.2.1.3.2 Lift Check Lift checks are based on globe valve body designs and as a result are available in either the regular, angle, or wye configuration.
The regular is the most common, even though it has the highest pressure drop. The angle lift check is designed to be used in a 90* pipe bend. Installed in place of an elbow, this valve-eliminates extra welds, and minimizes the additional pressure drop in the system. The wye lift check has the lowest pressure drop of DRAFT 6-10 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE the three lift checks but is still greater than most swing checks.
It is not generally supplied in larger sizes because the weight of the disc on the guides can impair operation. In many designs wye lift checks are supplied with a spring above the disc to compensate for friction between the disc and guides.
All lift checks should be installed with the bonnet vertical. This means that regular lift checks should only be used in horizontal lines, and angle lift checks should be installed with the normal flow up. Wye lift checks can be installed in either horitontal lines or in vertical lines with the normal flow upward. Packless type globe and lift check valves should only be used in relatively clean environments as close tolerances promote damage to the seat area from slurries or particulates.
6.2.2.1.3.3 Tilting Disc Check The tilting disc check (TDC) valve offers significant advantages over swing checks or lift checks, when high velocities are present, but perform poorly when return velocity and differential pressures are small. Without a large force in the reverse direction, TDC's with netal seats will not seal tightly. A TDC has less tiow resistanco than a lift check, but has a greator flow resistance than a swing check valve.
6.2.2.1.4 Plug Valve The major application for this valve is to function as a complete shut-off. It may be used for throttling where accurate adjustment is not necessary. It is normally used in applications with low temperatures and pressures. The simple design offers easy operation, positive closure, and therefore lends itself to automatic control. In addition to the two-way valves, multiple port arrangements are possible for special applications such as flow diversion or blending. Plug valves are limited to low temperature, low pressure application (i.e., 300 lb. ANSI Class, 200*F).
6.2.2.1.5 Butterfly Valve The butterfly valve has the advantage of combining in one val.e, the block-valve (on/off) f 'nction with the throttling-control function. This could require a positioner' to assure that proper valve control is obtained, Fit it does allow for combining the two functions into one valve. Also, the single wafer-disk that pivots in the body can easily be operated manually or automatically. The use of geared operators, levers, electric-motor drives, air-cylinder, or hydraulic-cylinder operators, or diaphragm operators is quite common for local or remote operation of butterfly valves.
l DRAFT 6-11 July 25, 1992
SYETEN 80+" DESIGN CERTIFICATION DISTRIEUTION SYSTEMS DESIGN GUIDE l
l 6.2.2.1.6 Diaphragm Valve Diaphragm valves rely on a flexible diaphraigm to block fluid flow. 4 Both high and low weir designs are available. The high weir causes less flexing of the diaphragm, but produces higher pressure drop.
. Diaphragm valves can be used for throttling and to handle solids-laden streams as well as in clean service. They have no pockets to trap material. Pressures and temperatures are usually low (215 psig and 300*F maximum) because the diaphragm is not able to withstand extremes. Diaphragm failure and replacement can occur j and cause considerable damage when handling corrosive chemicals.
6.2.2.1.7 Ball valve The ball valve is limited to those temperatures and pressures :
cllowed by the seat material. They are not limited to a particular fluid material.
These valves are of the on-off variety. However, the ball valve provides not only tight shutoff but also good flow characteristics c approaching those of an equal percentage valve. For this reason, it is often applied as a combination throttling and shut-off valve.
6.2.2.1.8 Relief Valve Relief valves are required to protect against exceeding the design pressure of a system or component. The design pressure of the equipment the pressure relief valve is intended'to protect will determine its set pressure. These valves are designed primarily for liquid service.
The function of the relief valve is to sense a pressure build up in the system and to provide a slow path for material out .of .the system. Pressure build up is sensed by a force-balance arrangement that consists of process pressure acting on a fixed __ area and opposed by a spring or weight.
The direct, spring-opposed pressure relief valve usually_has an angle body. The inlet connection -is suitable for the upstream temperature and ' pressure, while the outlet side and bonnet are designed for lower pressures. The outlet-side is normally larger to allow for expansion of the flowing medium.
6.2.2.1.9 Safety Valve Safety valves are-generally.used in steam service. When used in superheated steam service over 450'F, _ the body,- bonnet, and spindle-should be_ carbon steel or higher. alloy material.
DRAFT 6-12 July 25, 1992
SYSTEN 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 6.2.2.1.10 Safety-Relief Valve This valve is an automatic pressure-actuated relieving device suitable for use either as a safety valve or relief valve, depending on the application. It is also used on the discharge of positive-displacement pumps and compressors for thermal expansion of liquids and gases. Lifting levers are required for hot water (greater than 140'F), air, and steam service.
6.2.2.1.11 Control Valve The three major types of control valvest globe, butterfly, and ball are used in throttling applications. The throttling action is a function of the pressure-drop across the valve.
Cage guided globe valves are typically used for steam letdown' or large differential pressure applications. Butterfly control valves would be used for steam or water service with a low to moderate differential pressure. Ball valves are general service, low differential pressure throttling devices that could be used - in superheated steam lines or for corrosive process fluids.
6.2.2.1.12 Solenoid Valve There are two types of scienoid valves - the modulation type and the shut-off (isolation) type. Modulation solenoid valves are.
normally used for small line sizes. Precautions for solenoid valves include:
A. Limiting interpass temperature when welding in-line.
B. Using in clean systems since many solenoid valves are pilot-operated and have small passages.
C. Instal.'.ation in an upright position for proper operation.
6.2.2.2 valve Orientation Considerations 6.2.2.2.1 valve Types 6.2.2.2.1.1 Gate Valve The gate valve is extremely versatile as an isolation valve. The use of pressure as the primary sealing force enables it to seal tightly at high pressures. Gate valves are designed to take advantage of differential pressures, using the resultant force to seal the disc. Where gate valves incorporate a secondary wedging force, they can be used to seal reliably at low pressures as well.
In the absence of a differential sealing force, the wedging force provides the unit loading required for metal to metal sealing.
DRAFT 6-13 July 25, 1992 l
. ._ _ _ _ . . _ _ _ _ _ _ _ _ _ _ _ _ . _ ._ __._._.j
_ _ - _ _ _ _ _ _ .__ _ _ _ _ __ _ ___ . _ _ _ _ _ - __m .
SYSTEM 80+5 DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE Because the sealing force is normal to the direction of disc movement, operation requires less force than most other valves.
The force that must be overcome is mainly due to the friction of the disc being forced against the seat by the differential pressure. The actual force a gate-actuator must overcome is a force equal to the differential pressure times a coefficient of friction, (generally 0.3 for a wedge gate and 0.2 for a parellel seat gate). This results in the use of a relatively small actuator on most gate valves. Small bypass valves are sometimes used to equalize pressure prior to opening large, high pressure valves.
Gate valves should not be used as throttling devices due to erosion at the edge of the disc and seat ring when they are exposed to the turbulence produced by the partially open gate.
6.2.2.2.1.2 Globe Valve Globe valves are used as throttling devices. The streamlined surface that the plug presents to the flow, minimizes turbulence (and resulting erosion) and permits reliable control of the flow rate. The smooth profile is especially critical when high energy fluids must be controlled over a wide range. The high' velocities through the seat area, when the valve is throttled, can cause !
severe erosion of any obstructions in the flow path. In addition to the potential damage to the dise the turbulence created by using a valve not designed for thrott.bng service can cause erosion i.
of the adjacent body servic .
f The opposite unidirectional nature of the globe valve for :
throttling and shut-off should b- carefully considered. These two functions should not be combined in a single valve if sealing and ,
throttling are in the same direction. When the throttling function is required in one direction and shut-off is desired in the other, a globe valve is an ideal choice. Because globe valves have poorer flow characteristics (i.e., greater pressure drop), and require larger actuators than gate valves, they are not considered as good l a choice for solely isolation service. Note that globe valves must be procured for their throttling service conditions. Also, they l are not designed for large differential pressures in t.he reverse direction due to the tendency to unseat the disc.
6.2.2.2.1.3 Check Valve -
Check valves are designed to prevent the reversal of f1cw in a line automatically. Where the flow in a line is in ene direction and ;
isolation is in the opposite direction, the ability of a check valve to close independently of any outside signal can be very useful.
Because the sealing force in a check valve is obtained solely as a [
result of differential pressure, obtaining a tight seal at low .
differential pressure is difficult, particularly with metal seated ,
DRAFT 6-14 July 25, 1992 ,
l
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE valves. The large unit loading necessary for a tight seal at low pressures is not present in a check valve,.but when environmental conditions permit the use of a resilient seat material, the weight of the disc can sometimes provide enough force to seal. This aspect is useful where low pressure differentials exist.
6.2.2.2.1.4 Plug Valve The plug valve is of the " block" or complete shut-off type.
Several basic features make the plug valve ideal for power plant application. It has no projecting yokes or b.cnnets, no exposed threads, and no underhanging body to waste vital space. The plug valve can safely and efficiently handle gas and liquid fuel, boiler feedwater, condensate, and similar mediums.
The plug is the only movable member. The valve is opened'by rotation with the plug turning on a seat. Rotation eliminates the need for raising and lowering a movable valve member, and protects seating surfaces from exposure to corrosive elements.
One feature of the plug valve is the quick opening and closing operation, a quarter turn fully opens or closes the valve. Valves are wrench, gear, air, or motor operated. Plug valves have a polymer base sleeve which limits normal operating fluid temperatures to approximately 200*F. They are not restricted to one-way flow, (i.e., the valve can be installed in either direction because it holds pressure in either direction).
l 6.2.2.2.1.5 Butterfly Valve l
Butterfly valves often appear in modified form to suit requirements such as tight shut-off, tailored characteristics, better control performance, or higher rangeability.
They are normally used in isolation and moderate throttling applications for low pressure / temperature services. In leak-tight shutoff applications, soft seats should be specified. Advantages of butterfly valves are compactness and ease of installation. Two disadvantages are poor cavitation performance and the possibility of damage to the seat and disc when throttling at low flows.
1 1
6.2.2.2.1.6 Diaphragm Valve This valve consists of three simple elements; the valve body, valve diaphragm, and valve bonnet assembly. The diaphragm in this valve i serves as the closing, or seat, member as well as the partition that separates the valve working parts (bonnet) from the fluid l passageway. The diaphragm is not used as a packing substitute, but instead is used as a dynamic seating element, and eliminates the necessity for. conventional valve stem packing material.
DRAFT 6-15 July 25, 1992 >
.~
SYSTEM 80+5 DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE The attribute of bubble-tight : eating in this valve design results in its principal application where drip-tight, bubble proof closure is required.
The standard elastomeric rubber-base diaphragm operating temperature is from 180'F to 200*F for special heat resisting diaphragms. The use of Teflon as a diaphragm material permits the ase of the valve at temperatures up to 300'F.
6.2.2.2.1.7 Ball Valve Ball valves are basically modified plug valves. The wall has a port opening that joins with the body in the open position. Ball valves are mainly used for on-off services, however, they can also be used satisfactorily for throttling service in low differential pressure applications. They are quick to operate, easy' to maintain, require no lubrication, give tight sealing with low torque, and exhibit a pressure drop that is a function of the port size selected.
One disadvantage is that when closed, some fluid is trapped between the seats and in the hole of the ball, which might be damaging at high temperatures.
6.2.2.2.1.8 Relief Valve Relief valves prevent overpressurization of process equipment and piping. Such valves operate automatically at a predetermined pressure to vent fluid and relieve the excess pressure.
The pressure-relief valve usualJy consists of an angle type body having an inlet flange at the bottom and an outlet flange at the side. The inlet flange is designed for inlet pressure and inlet temperature ratings. The larger outlet flange usually has a lower pressure rating.
6.2.2.2.1.9 Safety Valve The overall design of the safety valve is similar to that of the-relief valve. In steam, air, gas, and vapor services, the safety valve pops open when pressure reaches the set pressure. Pressure will continue to rise .usually 3% to 33% above the set pressure.
After relieving (called blowdown), the disk reseats at about 4%
below the set pressure.
6.2.2.2.1.10 Safety-Relief Valve This valve incorporates the same basic design as the relief valve.
Its function is to sense a pressure build up in the system and to provide a flow path from the system. Pressure build up is sensed by a force-balance arrangement that consists of process pressure act.ing on a fixed area and opposed by a spring.
DRAFT 6-16 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE 6.2.2.2.1.11 Control Valve control valves are the basic regulatory devices in any process operation handling fluid streams. They are usually the same size or one size smaller than the upstream pipe size, never larger.
Control valves are much smaller than line size when high pressure a differentials have to be absorbed.
The three basic types of valves used for control valve design are globe valves, specially designed ball valves, and butterfly valves.
Globe valves with cage style trim are standard for control vtives.
The cage offers valve-plug guiding for stability in the region
- where maximum pressure drop occurs.
l q 6.2.2.2.1.12 Solenoid Valve Solenoid operated valves, normally referred to as simply solenoid i valves, get their name from the fact that they are actuated by a solenoid motor. The valve body is normally a globe style.
Solenoid valves can be either on-off or modulating valves, although the latter in seldom used except for small valves. Actuation can be direct acting for moderate pressures or pilot assisted for high pressures. A t.najor advantage of solenoid valves is that they can be seal welded to prevent external leakage.
6.2.2.2.2 Valve Body A. Valves should be oriented with the stem vertical unless i specifically permitted by the manuf acturer's drawing (see Figure 6.2.2-1), or if required otherwise to comply with an overriding requirement.
i B. Check valves must be oriented vertically up or horizontal unless specified otherwise by the valve manufacturer (see Figure 6.2.2-2).
C. Swing check valves may be placed in vertical runs providing the normal flow is upward. Swing check valves, 8" and larger should not be installed in vertical pipe runs unless horizontal installation is not possible or feasible from other good installation practices. For i swing check valves adjacent to fittings, the plane of the fitting should be perpendicular t'o the clapper arm hang pin. If the requirements of Section 6.2.2.3.1.1 cannot be
- met, as a minimum, a 6" spool is needed between a swing check valve and a downstream valve or fitting to prevent clapper arm interference.
4 DRAFT 6-27 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE FIGURE 6.2.2-1 valve Bedy orientation The preferred valve body orientation is with the bonnet vertical, in a horizontal pipe run. This produces a symmetric natural balance in the valve yielding minimum wearing forces on moving valve parts. Also, stresses are greatly reduced with the valve in this orientation. ,
K 1 M
- BONNET
/
4 ._
__+ __- )
0 0
,gj,
,c PREFERRED VALVE ORIENTATION 1
)
DRAFT 6-18 July 25, 1992 ;
y .. - . - e..%,. ,w.... ~ ,m., ..
p..-*~=r r v - - - - - - - - <- ~->w--*
.- . -.- . - . _ _ . - _ - . . . - . - _ . - . - . . . - . - . . . - .. _ - . . . . . . . . ~ . _ .
I SYSTEN 80+" DESIGN CERTIFICATIO3 DISTRICUTION SYSTEMS DICSIGN GUIDE i
FIGURE 6.2.2-2 ,
Check Valve Body orientation l
Check valves should be placed in horizontal !
pipe runs with the bonnet vertical. While not j recommended, most check valves may be placed in '
- vertical runs, provided that the normal flow
direction is vertical. l I
i 1
BONNET ;
mm mn rm 1 ._J
.} --
(
p
~
'~
) ;
ln}
Q :
i I
PREFERRED CHECK VALVE ORIENTATION i r
i l \
i DRAFT' 6-19 July 25, 1992 -;
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~ - - - - - ...--.-. ._.-_- _- - .-- _-._- -.~.--- - ~-
SYSTEN 80+5 DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE-D. All lift check valves should be installed with the bonnet '
pointing up. Therefore, regular lift check valves should be located in horizontal piping, and angle lift check valves should be located with. normal flow up. Wye lift !
check valves may be located in either horizontal piping or !
vertical piping if the normal flow is upward. i E. Relief valves should always be oriented with the bonnet !
vertical ~ (see Figure 6.2.2-3) . !
F. Large butterfly valves (3.6" and up) should have at least
- 8 diameters of straight pipe both upstream and downstream ,
(see Figure 6.2.2-4). . If this cannot be- met, the .
following guidelines should be used. !
i
- 1. Adjacent to elbow, the valve-shaft should be in'the plane of the elbow. centerline.
- 2. Adjacent to contrifugal pump discharges with the pump shaft vertical the valve shaft should be horizontal,J and with the pump shaft horizontal,-- the valve shaft -
- should b0 vertical.
- 3. Adjacent to vertical lift pump, the valve shaft should be vertical.
G. Control valves should have a 6" minimum spool piece to allow for hanger attachment and/or inservice inspection '
requirements between the reducer (if' required) ~and valve -
body. Note that this . reducer does not violate the straight run requirements.
H. Gate valves, which are subject to temperatures in excess of 200*F, 24 inches and larger, should be oriented with the valve stem horizontal. or above to prevent overpressurization of the valve dua -to possible-. heat-expansion of entrapped fluid in the bonnet cavity.-
I '. Valves 'should be oriented with the connet . vertical to prevent creation of crud traps (See Figure 6.2.2-5) .
J. When locating . valves,. - the - orientation - should allow for required valve disassembly and. reassembly activities (see '
Figure - 6. 2. 2-6) .
j 6.2.2.2.3 operators 6.2.2.2.3.1 Electrohydraulic Electrohydraulic valves should-be installed with the operator stem vertical.
1 I
DRAFT 6-20 July 25, 1992 )
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I I
4 SYSTEM 80+" DESIGN CERTIFICATION !
DISTRIBUTION SYSTEMS DESIGN GUIDE I i
FIGURE 6.2.2-3 i
i d
Relief Valve Body Orientation i
Relief valves should be oriented with
- the bonnet / spring vertical.
1 3
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- BONNET /
j g SPRING HOUSING i
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RELIEF I l VALVE
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s Discharge i , 3 Inlet i
July 25, 1992 6-21 DRAFT
_ _ _ -_ _ __. _ - _.__m.._....___ . _ . _ _ _ . _ . _ ._. _ _ _ _ . - _ _ - _ _ . - _ . -. .. .. -
SYSTEli 80+* DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE FIGURE-6.2.2-4 '{
Butterfly Valve Conficuration r
Butterfly valves should have eight pipe diameters of straight both upstream and downstream of the valve, t
8 Pipe Diameters 8 Pipe Diameters
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DRAFT 6-22 July-25, 1992 ;
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SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTICH SYSTEMS DESIGN GUIDE e
FIGUPI 6.2.2-5 Valve Bonnet Orientation Valve bonnets create crud traps when installed below the pipe centerline; With the bonnet vertical, the valve is better able to drain. This is especially important in radwaste systems, j
w BONNET lion-PREFERRED VALVE ORIENTATION DRAFT 6-23 July 25, 1992
SYSTEM 80+* DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE FIGURE 6.2.2-6 Non-oreferred Bonnet Orientation ,
l Valve reassembly is extremely difficult l with the bonnet facing downward. Valve parts such as rings, seals, springs, and sleeves must be inserted in the valve before the bonnet and stem are inserted.
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EXTREMELY DIFFICULT TO HOLD SMALL PARTS IN PLACE DURING REASSEMBLY NON-PREFERRED CONFIGURATION DRAFT 6-24 July-25, 1992 l
SYSTEN 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 6.2.2.2.3.2 Electric Motor-operated Electric mot -operated (EMO) valve operators should be oriented such that neither the motor nor limit switch housing is below horizontal. If, due to other restrictions, it is not possible to meet these criteria, it may be necessary to rotate the operator on the valve until these criteria are satisfied, unless shown to be acceptable by the valve manufacturer.
6.2.2.2.3.3 Chain Wheel Operators Valves tc be equipped with chain operators can be rotated to horizontal unless specifically stated otherwise by the manu f acture r's drawing. If a listing is not available which identifies chain operated valves, the following guidelines can be used to determine the possibility of a valve requiring a chain operator.
A. The valve is operated on a routine basis (monthly or more often).
B. The valve is operated in the plant startup sequence.
C. The valve is operated in the plant shutdown sequence.
D. The valve is operated _for emergency bypass and/or isolation purposes.
6.2.2.2.3.4 Pneumatic Piston Operators Valves equipped with pneumatic piston opSrators should be limited to vertical orientations. Orientations other than this will severely reduce the operator life.
6.2.2.2.4 End Connections Valve end connections should be selected considering removability, welding, and bolting access.
6.2.2.2.5 Manufacturer's Instructions Manuf acturer's instructions should clso be considered, in addition to these general routing guidelines.
6.2.2.3 Valve Location Considerations 6.2.2.3.1 Valve Arrangement 6.2.2.3.1.1 Line Valves Generally, valves should not be located adjacent to fittings, (See l Figure 6.2.2-7), especially with corrosive fluids because of the DRAFT 6-25 July 25, 1992 1
. - ~ .
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE turbulence produced at the fittings. Valve performance and life is greatly increased by adding straight runs of pipe before and after valves. Spool pieces between fittings and valves aid in supportability. Optimum length spool pieces upstream and downstream of the valve would be 4 pipe diameters.
6.2.2.3.1.2 Butterfly valves Ideally, butterfly valves should have at least 8 pipe diameters of straight pipe both upstream and downstream of the valve (see Figure 6.2.2-4).
6.2.2.3.1.3 Control Valves Control valves should have at least 10 pipe diameters of straight pipe upstream and 8 diameters downstream, for maximum pressure recovery (see Figure 6.2.2-8). If these cannot be met, a minimum of 4 pipe diameters upstream and downstream may be used.
Where the minimum requirements of 4 pipe diameters upstream and downstream cannot be achieved, piping should be rerouted to conform to these requirements. ;
For high flashing flow situations, such as into a flash tank or i condenser, the control valve should be placed as close as possible to the vessel with no directional changes after the valve.
6.2.2.3.2 Maintenance The valve location can hinder maintenance without proper design considerations. The following guidelines are applicable to all valves, but trst consideration should be given to valves with operators, switches, or other types of moving parts, or electric controls which will be more likely to require maintenance.
6.? 2.3.2.1 Location Requirements A. Frequently operated valves should be more accessible than infrequently operated valves. For the purposes of this criteria, infrequently operated valves are listed below.
All others should be considered f requently operated valves.
- 1. Drain valves
- 2. Vent Valves
- 3. Equipment Isolation Valves
- 4. Pressure Test Valves
- 5. Local Sample Connection Isolation Valves
- 6. Tell-tale Isolation Valves
- 7. Relief Valves DRAFT 6-26 July 25, 1992
. . _ . . _ . _ _ _ . _ . _ _ _ . . _.. _. .._._ . .__ . - . _ . ____. ~ ~ . . .__. .._ _ _ _ . _
s i SYSTEM 80+" DESIGN CTjATIFICATION i DISTP.IBUTION SYSTEMS DESIGN GUIDE l FIGURE 6.2.2-7 i Line Valve Confiauration 1 I
! FITTINGS PRODUCE TURBULENCE IN THE FLOW AREA i
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, for proper function
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( for better-performance -
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DBAFT .6-27 July'25,:1992 -
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= . - _ _ . .. - . - . -
SYSTEM 80+* DESIGN CE!'TIFICATION DISTRICUTION SYSTEMS DESIGN GUID3 FIGURE 6.2.2-8 Control valve Conficuration It is preferred to have tun pipe diameters of straight pipe upstream of the control valve and eight pipe diameters downstream of the valve.
Placing control valves immediately adjacent to fittings should be avoided.
8 Pipe Diameters 10 Pipe Diameters
~ - - -
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- m_W CONTROL VALVES DRAFT 6-28 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE B. Valves should not be located n0xt to walls where they are not easily accessible.
4 C. Valves should be placed close to floors or operating j platforms to make them more accessible, but not in
- maintenance access areas.
D. "alves should accommodate reach red configurations.
6.2.2.3.2.2 Removal Requirements A. Maintenance and Removal -
For valve maintenance and
! removal, manufacturer's specifications should be reviewed
! to determine if speelal tools are requireo. Space should
! be provided for use of these tools.
B. Disassembly - Space should be allowed for disassembly of l valves. Disassembly dimensions should be shown on valve outline drawings.
C. Flanges - For flanged valves with stem leakoffs, flanges or another type of di,- onnect should be provided for the stem leakoffs to eliminate cutting and rewelding.
i' O. For valve packing leakoffs, tubing connections should be used instead of flanges.
E. Clearance should be provided above ch0:k valves for
- pulling internals during maintenance. This is especially important for ASME Class 1 check valves.
F. Clearance should be provided for pulling relief valves which must ce bench tested periodically, G. Routing piping over and around valves, blocking their 1 access, should be avoided.
H. Relief valves should always be flanged.
6.2.2.3.2.3 Valve Type 6.2.2,3.,2.3.1 Gate Valve Most gate valves will at some point require reworking of the
, seating surface. Allowing adequate maintenance space will aid in the ability to relap the valve seat in-line. Proper maintenance pull spaces also allows quick, easy removal. It is extremely 4
important that gate valves 2%" and larger with service temperatures above 200*F be oriented with the stem horizontal or above (vertical is preferred). Orientations other than this could cause the valve DRAFT 6-29 July 25, 1992
-m--
1 SYSTEM'80+5 DESIGN CERTIFICATION- '
DISTRICUTION SYSTEMS DESIGN GUIDE to become overpressurized due to possible heat expansien of entrapped fluid in the bonnet cavity.
6.2.2.3.2.3.2 Globe Valve Globe valves are fairly low maintenance items. Replacement screw-in type seats improve maintenance greatly. The horizontal globe is the easiest to maintain when the stem is vertical. It can be installed in either horizontal or vertical lines with flow in either direction. The Y globe can also be installed in either horizontal or vertical lines. In vertical lines it is not recommended for installation with the stem angled down. Besides maintenance concerns, the bonnet becomes a crud trap. Th'e angle globe allows the replacement of an elbow with a valve and takes advantage of the 90' bend. This eliminates welds, reduces pres "re drops, and efficiently uses available space. When used or throttling, the flow in the vertical leg should be upward, and for isolation service should be downward. The Y-angle globe installation should be opposite that of an angle globe.
6.2.2.3.2.3.3 Check Valve Swing chtcx valves can be installed in either horizontal lines or in vertical lines wir.h the normal flow upward. Swing checks should not be used in lines where the flow pulsat' 3 or fluctuates frequently without special attention being paid to tne hinge bearing areas. The angle lift check is installed in place of a 90' pipe bend. Installed in place of an elbow, this valve eliminates welds and minimizes the additional pressure drop in the system.
All lift checks should be installed with the bonnet pointing up.
This means that regular lift checks should only be used in norizontal lines, and angle lift checks should be installed with the normal flow up. Wye lift checks can be installed in either horizontal or vertical lines with the normal flow upward.
Check valves should not be installed more than 45' from vertical.
Maintenance becomes more difficult when installed below the I
horizontal.
Swing check valves downstream of fittings (i.e., elbows, tees) should have the fitting oriented to the plane perpendicular to the swing check valve clapper arm hang pin.
6.2.2.3.2.3.4 P3ug Valve Plug valves can be used it: /tical or horizontal piping and for two-way flow. Plug valves we fairly low maintenance items which can be reclaimed after extene'M ase by a simple resleeving process.
Sufficient maintenance spa- ab ec the valve should bc provided to permit in-line resleeving.
DM.r 6-30 July 25, 1992 m g r _ - - - ---------
i SYSTEN 80+" DESIGN CERTIFICATION
~
DISTRI;UTION SYSTEMS DESIGN GUIDE i
6.2.2.3.2.3.5 Butterfly Valve
) Butterfly valves can be used -in either vertical or horizontal 4' ppmg and for two-way flow. The amount of maintenance required
- depends on the' type of operation, process' fluid, and the seating
) material.
4 l < he valve scem-should be in the same plane as the upstream fitting.
This allows loading of the valve disc by the process-fluid which
] minimizes torque on the disc.
i l 6.2.2.3.2.3.6 Diaphragm Valve 4
l Diaphragm valves can ce used in either vertical or horizontal i piping and for two-way flow. The bonnet should_ remain above the i horizontal to eliminate the creation of a crud trap.
L
- The diaphragm acts as a part of the-seat and as a separating member of the bonnet, eliminating the need for packing. The three element
- construction has the advantage of permitting in-line maintenance
- without requiring removal and it eliminates stem repacking, seat-j grinding, and the necessity for selective fits during reassembly.
i Note that typical vendor recommendations are that diaphragms be l replaced -for all valves at five year intervals.. Each time the diaphragm is replaced, th6 stem travel stop should ~ be reset.-
Therefore, ample space should be provided to allow this maintenance l to be performed. Also,- placement of these valves in high radiation j zones should be minimized.
i 6.E.2.3.2.3.7 Ball valve i Ball valve maintenance usually requires the installation of new
- seat seal- a new ball and stem, new packing, gaskets, bolts, and
- r. ts. . . t ti a remachining of ball valve components is necessary.
Gener* .y, . proper seating can be' corrected in-line.
These 11; w can be used in either-vertical or horizontal piping and fc: ' wm sy flow.
l .
! 6.2.2.3.2. 8 Pressure Relief Valve i Pressure relief valves are relatively low maintenance items, having j a simple design and few moving parts. However, provisions for j removing these valves for bench testing should be provided.
l The inlet piping on relief valves, safety valves and safety-relief
- valves should be at least equal in area to the valve inlet -
2 conditions. Safety valves on power boilers must be mounted on
- nozzles directly_ connected
- to the boiler without intervening pipe.
Otherwise, relief valves and safety-relief -valves protecting i vessels -may. have their inlets -connected to -a common piping header.
1 DRAFT 6-31 July 25, 1992 f
3
SYSTEM 80+" DESIGN CERTIFICATION :
DISTRIEUTION SYSTEMS DESIGN GUIDE Pressure relief =valvos-should be mounted upright with the spindle in the vertical position in_such a manner that liquid does not accumulate on the-discharge side of the--valve. )
Relief valve discharge piping should be oriented and-routed to' .
minimize the valve , backpressure. The backpressure should be verified to be within the valve manufacturer's allowables.- Safety valve discharge piping which could contain steam should be routed to drain any condensation to prevent water slug damage during valve actuation.
6.2.2.3.2.3.9- Control valve For in situ maintenance, clearan'ce space is required-below and above the-valve for removal of the- seat,- plug, actuator cover,-
spring, and yoke. Clearance space requirements should be obtained from the manufacturer's drawings.
The best position for a control valve is with the stem vertical.
A control valve can operate in angular, horizontal, _or vertically downward position. The actuator determines- the best operating-position.. Large angle control valves are an exception; a horizontal position is the most practical.
6.2.2.3.-2.3.10 Solenoid valve The best orientation is with-.the__ stem vertical (pipe horizontal) for both operability and_ maintenance. Space should be_provided above the valve to permit disassembly.
6.2.2.3.2.3.11 Pressure Seal Valve.
Available pressure seal valves are gate, globe, and check-valves, 600 lb ANSI Class and greater, 2% inch and larger. These valves l
should be in a vertical orientation to facilitate L disassembly /
l reassembly. Correct line-up of the body and bonnet 'is critical and l orientation in any other position hinders proper assembly.- Space
! above the valve is required to allow maintenance.
6.2.2.3.3 Operability A. Reach rods should- be used for remote actuation of infrequently operated valves which . require shielding.
l This allows valve operation from behind the safety!of a
! shielded wall.
L B. Manually-operated valves more than 5 feet _above the floor should be_ oriented such that.they can be equipped with a chain operator.-
DRAFT 6-32 July 25, 1992 r
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SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTIOJ 3YSTEMS DESIGN GUIDE
! 6.2.2.3.4 Accident Accessibility Manual valves requiring operation during an accident should be in low radiation areas or have provisions for temporary shielding.
6.2.2.3.5 Equipment Proximity The valve functivn should be corc idered in its placement (e.g.,
4
, heat exchanger isolation valves should be in the proximity of the heat exchanger) . Also, valves that are normally operated together
- should be in close proximity.
4 4
6.2.2.4 Seismic Acceleration Valve seismic accelerations should not exceed allowable vendor j allowables. In lieu of specific values, generic seismic valve accelerations may be used provided the valve is specified to these l seismic acceleration limits.
1
- 6.2.2.5 Water Hammer Considerations J
Valve specifications should specify any limitations on valve
, operating times to preclude water hammer.
6.2.3 SUPPORT GUIDELINES
.2.3.1 Generpl Guidelines In order to avoid costly support / restraint (S/R) rework and
! reanalysis, the designer should follow these layout guidelines for either new systems or modifications. Compromises to these guidelines are sometimes necessary but doing so risks creating other complications, such as awkward S/R design and interferences.
l one of the goals or the System 80+ piping design effort is the development of a standard piping support system for all sites. If
! the guidance provided herein proves to be too conservative to uphold this goal, project management must be consulted.
s 6.2.3.1.1 Grouping and Locations
- A. Piping should be routed close to structures (ceilings, walls, columns, floors) which can be used for support attachment.
B.
When possible, piping- should .be grouped for common supports. Interactions should be minimized by separating
' non-seismic and seismic piping. _See Section 6.1.5.1 for non-seismic interactions. See Section 6.2.3.5.2.6 for interactions between seismic and non-seismic piping.
- C. In pipe groupings, a horizontal or vertical pattern or grid should be maintained.
i The pipe bottoms should be located at the same elevation in each horizontal row to facilitate common vertical supports (see Fi'gures 6.2.3-1 and 6.2.3-2).
DRAFT o-33 July 31, 1992 1
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4
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SYSTEM 80+" DESIGN CERTIEICATION DISTRIBUTION SYSTEMS DESIGN. GUIDE ~ ;
D ._ When-possible, piping should be--separated _or grouped by-
-temperature'. This will ensure similar thermal performance-for gang support design.
6.2.3.1.2 Clearances
- A. A 12" minimum clearance should-be provided near walls. and.
columns for clamp and support attachment (see Figure 6.2.3-3).
B. A minimum 12" vertical _ clearance should be _ provided to floors and ceilings.
C. Sleeves should be located a minimum - of 12" from the
- corners of walls (see Figure - 6.-2.3-4) . ,
D. For high temperature (2200'F) seismic piping, the lateral and vertical minimum clearance to support points should be increased to 3 feet- on pipes- smaller than 12" nominal pipe size (NPS), _ and .to 4 feet . on pipes 12" NPS and larger to
, allow for installation of snubbers.
E. Where space permits, a 12" minimum lateral and vertical clearance _ should be maintained between pipes 'in groupings except - for high temperature - seismic piping whers the provisions- of Section 6.2.3.1.2.D -could necessitate staggering of pipe locations ((see_ Figures 6.2.3-1 and 6.2.3-5).
F. For high temperature piping whe_re large vertical movements are expected, spring supports and, for seismic lines, vertical snubbers could be required. .In this , case, -
additional vertical clearance should be-provided above or-below the piping (see Figure , 6.2. 3-6) .
G. Figures 6.2.3-7. through 6.2.3-10. show typical-j support / restraint-standard components. Figures 6.2.3-11:
through 6.2.3-23 show typical support / restraints.-
\
6.2.3.1.3 Piping _
A.. Piping runs should be avoided below large ducts, cable L trays,-or other. wide obstructions whero the-line-would be supported from above (see Figure 6.2.3-24) . ;
B. Piping should not be routed near concrete block walls if
- 1 possible- .
C.. Piping should be routed along embedded plates as much as ,
possible. j i
DRAFT 6-34 July 25,'19S2 {
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- SYSTEM 80+" DESIGN CERTIFICATION i DISTRIBUTION SYSTEMS DESIGN GUIDE 1'
FIGURE 6.2.3-1 '
Succort Grid Pattern When adding pipe, a horizontal.or vertical pattern s 4
should be maintained. ;
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' DRAFT 6-35 July 25, 1992
4 d
SYSTEN 80+5 DESIGN CERTIFICATIONL DISTRIEUTION' SYSTEMS' DESIGN GUIDE -
1 FIGURE 6.2.3-2 Typical Support Grid
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DRAFT 6-36 July 25, 1992 [;
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4 1 SYSTEM'80+" DESIGN CERTIFICATION-I DISTRIBUTION SYSTEMS DESIGN GUIDE
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-FIGURE .6.2.3-3 1.
i Wall column Pipe Clearance- .
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SYSTEN 80+* DESIGN-CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE' FIGURE =6,2.3 Sleeve Clearances Sleeves should be at least'12" from the corners of walls ~.
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SYSTEM 80+* DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE FIGURE 6.2.3-5 Vertical Clearance Between Pipes N
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12" MINIMUM VERTICAL CLEARANCE I
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DRAFT 6-39 July 25, 1992
l' SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE FIGURE 6.2.3-6 Non-oreferred Conficuration for Pipina With Larce Movements Pipes expected to have large displacements should not be run one above the ,
other because the upper pipe blocks space required for spring supports and snubbers for the lower piping.
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l-SYSTEM 80+" DESIGN CERTIFICATION' DISTRIBUTION SYSTEMS. DESIGN GUIDE FIGURE 6.2.3-7
-Tvoical Standard Hancer
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' DRAFT 6-41. July 25, 1992 1
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. SYSTEM 80+* DESIGN CERTIFICATION DISTRIEUTION SYSTEMS DESIGN GUIDE FIGURE 6.2. 3-8 :
Tvoical Standard Hancer i -i l- 1 i '
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I l-DRAFT 6 July 25, 1992
4 4
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SYSTEM 80+" DESIGN CERTIFICATION-i DISTRIBUTION SYSTEMS DESIGN GUIDE 4
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4- FIGURE 6.2,3-9 i
i- Tveical Standard-Srubber 8
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) DISTRIBUTION SYSTEMS DESIGN GUIDE-
- i FIGURE 6.2,3-10 ;
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ELEVATION SECTION A-A-DRAFT 6-44 July 25, 1992-
- _ . . . .. . - , - .. .,...-.,. . , . .-... . .. . .. . - . - . . . . . - . . . _ , , . . . , . - , . _ . , ~ - . -
SYSTEM 80+" DESIGN CERTIFICATION
-DISTRIBUTION SYSTEMS DESIGN GUIDE FIGURE 6.2.3-11 Tvolca1 Succort / Rest raint WD .
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DRAFT 6-45 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE FIGURE 6.2.3-12 Typical Supoort/ Restraint I
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) SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE-t u
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SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE FIGURE 6.2.3-14 Tvolcal Supoo rt /Re st raint-EXISTING COLUMN ll
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DRAFT 6-48 July 25, 1992
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SYSTEM 80+" DESIGN-CERTIFICATION DISTRIBUTION. SYSTEMS _ DESIGN. GUIDE. .
FIGURE 6.2.3 Tvoical-Succort/ Restraint
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SYSTEM 80+5 DESIGN CERTIFICATION
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FIGURE 6,2,3-16 Typical Succort /Re st ra int
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DRAFT 6-50 July 25, 1992 l l
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-SYSTEM-80+" DESIGN CERTIFICATION.
DISTRIBUTION SYSTEMS DESIGN GUIDE i ,
i FIGURE--6.2.3-17 s j Tvolcal Support / Restraint i i
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! DRAFT 6-51 July 25, 1992 1
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SYSTEM 80+". DESIGN CERTIFICATION- -
DISTRICUTION SYSTEMS LESIGN GUIDE
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FIGURE 6i2.3-18 !
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DRAFT 6-52 July 25,.:1992 i
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SYSTEN 80+" DESIGN CERTIFICATION- j DISTRI30 TION SYSTEMS DESIGN GUIDE FIGURE 6.2.3-19 Tvolcal Suppo_rt / Rest rai nt ,
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6-53 July 25, 1992 DRAFT
SYST3M 80+" DESIGN CERTIFICATION-DISTRIEUTION SYSTEMS DESIGN GUIDE FIGURE 6.2.3-20 Tvolcal Support / Restraint
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DRAFT 6-54 July-25,_1992 -
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I DRAFT 6-55 July 25, 1992
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SYSTEM 80+" DESIGN CERTIFICATION
- DISTRIBUTION-SYSTENS. DESIGN-GUIDE 3
a i, FIGURE 6.2.3-22 3- Tvoical Sucoort / Rest raint 3
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DRAFT 6-56. July-25,.1992- ;
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- FIGURE 6.2.3-23 a
Typical Support / Restraint 1
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, - -.,,--,. _ _ _ _ _ , - - . . - . . , _ , . - . - . _ _ . . . . _ . , , . . . . , , . . . , ~ . . _ , , ~ . . . _ . <
SYS'"LM 804" DESIGN CERTIFICATION DISTRIBUTJON SYSTEMS DESIGN GUIDE FIGURE 6.2.3 24 Support Lay 2 tit J g gapla Trav
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- p q CJ s 6-58 July 25, 1992 DRAFT
SYSTEM 80+" DESIGN CERTIFICA'CION DISTRIBUTION SYSTEMS DESIGN GUID3 D. Avcid fitting-to-fitting and fitting-to-component configurations. A minimum of 6" should be provided between all fittings, if possible (see Figure 6.2.3-25 and Sections 6. 2. 5. 3.1. 2 and 6. 2. 6. 4) .
E. For seismic piping, if the nominal pipe size (NPS) ratio of the pipe run to the branch is less than 4:1 then the branch should consist of a straight tee followed by at least a 10" spool, then a reducer. If the ratio is greater than 4:1, then no 10" spool is required. The 10" spool allows a lateral support on the branch to act as an axial restraint on the ru;..
P. Valves and other concentrated weights or eccentricj ties should be placed at least one span, if not two, away from nozzles.
G. Large, heavy valve operators should be placed directly above or below the pipe centerline, preferably directly above.
H. The lengths of seismic and safety-related piping should be minimized to r.ue extent porsible (see Figure 6.2.3-25).
I. Where high temperature piping is insulated, space should be allowed for a saddle to be used to support the piping.
6.2.3.2 Snubber Minimization Supports the . serve as seismic restraints only (e.g., snubbers) should be minimized to the maximum extent possible. Minimizing snubbers reduces the inservice testing (IST) and maintenance requirements over the life of the plant, along with the resultant reduction in personnel radiation exposure.
6.2.3.3 Pipino Desian by Analysis For larger piping, particularly greater than 8" NPS, the optimum pipe routing would have the centerline of the pipe a distance "L" from the walls and ceiling. This would enable tha use of struts, ,
snubbers, and springs without having to build a frame. Figure i 6.2.3-27 provides recommended distances "L" _for typical pipe sizes, j Figures 6.2.3-28 and 6.2.3-29 illustrate desirable and undesirable '
pipe routings.
All ASME Class 1, 2, and 3 piping is designed by analysis. Other piping is also analyzed excluding that which is non-safety related and low temperature and low pressure (see Section 6.2.11 for field routing guidelines and restraints). Piping analysis is generally performed with the aid of a computer, and therefore the following DRAFT 6-59 July 25, 1992
1 SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN CUIDE FIGURE 6.2.3-25 Spool Pieces for Hancer Support s
(
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Pipe between fittings allow for '
hanger support.
l DuAFT 6-60 July 25, 1992 T
4 .r --
. . . - _ . ~ . . . . - . . _ , - - _ . . . . - - _ . - - _ _ _ - . - . . . - .
SYSTEN 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE FIGUPI 6.2.3-26 Seismic Ploino Lenoth Minimization i
SAFETY-RELATED NON-SAFETY RELATED NOZZLE .
l- . !
A J/ 8 CLASS-BREAK SAFETY- NON-SAFETY RELATED PELATED .
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NOZZLE A O I
CLASS BREAK ,
The length of safety-related' piping should be minimized.
DRAFT 6-61 July 25, 1992
SYSTEM 80+* DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE FIGURE 6.2.3-27 Pipe Clearance b
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NOMINAL PIPE SIZE LENGTH "L" 10" 35" (MIN.)
12" 37" 14" 43" 16" 44" 18" 45" 20" 46" 24" 53" 30" 56" 36" 60" 42" 71" ,
DRAFT 6-62 July 25, 1992 !
l l
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,7( Pipo clearance
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MORE DQSTRABLE DRAFT 6-63 July 25, 1992
SYSTEM 80+* DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN CUIDE FIGURE 6.2.3-29 Pipe Clearance for Gana Support
.N ,
s e
12" ;
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MIN
/ BOP Elevation P
- [ Lt = 6" For nominal pipe sizes 2" and less i EDGE OF WALL Li = 12" For nominal pipe sizes 3" to 4" Note: Largest pipe size governs Li l
l 1
A gang support is feasible in congested areas.
Piping should be routed so that the bottom of pipe (BOP) elevation is the same, i
Note: This applies to piping 4" NPS and smaller, i l l DRAFT 6-64 July 25, 1992 1
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE guidelines are not intended to replace those calculations but to serve as a conservative guide for locating supports and/or restraints through simple calculations.
6.2.3.3.1 Seismically Supported Pipe Seismic support spans should be assumed to be the same span length as those for simple gravity support spans (see Table 6.2.3-1) .
6.2.3.3.2 Vertical Supports Table 6.2.3-2 shows maximum gravity support spacing with the limitations as noted on the chart.
6.2.3.3.2.1 Support Locations Gravity supports are located using the recommended hanger spacing.
This does not take into account concentrated weights such as in-line pumps, flanges, or valves.
6.2.3.3.2.1.1 Concentrated Loads For significant weights, supports should be located as close to the concentrated weight as possible. Inservice inspection tolerances could limit how close a support can be. See section 6.2.6 for inservice inspection tolerances.
6.2.3.3.2.1.2 Equipment Connections The span by should be decreased by 1/2 for the first support from any equipment.
6.2.3.3.2.1.3 Terminal Ends Penetrations and points of embedded piping should be considered the beginning of the required span. Support points should be located using no greater than the calculated spans.
6.2.3.3.2.1.4 Vertical Piping Supports at the upper or lower end of risers should be located as !
close as possible to the elbow. This will normally be limited by inservice inspection requirements.
6.2.3.3.3 Lateral Supports (Seismic) ,
6.2.3.3.3.1 Concentratec Loads Lateral restraints should be assumed at each concentrated weight. ,
Inservice inspection requirements will limit how close a restraint !
can be placed.
i t
DRAFT 6-65 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE TABLE 6.2.3-1 Seismic Span Lenaths (with concentrated weights)
NPS (In). Schedule Conc. Wt. Sean "L" (Ft) 4 80 40 0.9 70 0.5 4 80 40 1.5 70 0.9 100 0.6 1 80 70 1.6 100 1.1 150 0.8 1% 80 70 3.6 100 2.9 150 2.1 200 1.6 2 80 100 4.3 150 3.3 200 2.7 300 1.9 24 BC 100 6.1 150 5.5 200 4.9 300 3.5 500 2.4 3 80 200 6.3 300 5.3 500 3.7 1000 1.9 4 80 200 8.1 300 7.4 500 5.9 1000 3.4 i
DRAFT 6-66 July 25, 1992 l
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SYSTEN 80+* DESIGN CXRTIFICATI@N DISTRIBUTION SYSTEMS DESIGN GUIDE TABLE 6.2.3-2 i Succested Pipe Support Spacina Succested Maximum Seacina Nominal Water Steam, Gas, or Pipe Size Service Air Service NPS ( I n ) ._ (Ft) (m)_ (Ft) (mL .
{
1 7 2.1 9 2.7 i 4.0 2 10 3.0 13 3 12 3.7 15 4.6 4 14 4.3 17 5.2 6 17 5.2 21 6.4 8 19 5.8 24 7.3 12 23 7.4 30 9.1 16 27 8.2 35 10.7 20 30 9 .1- 39 11.9 24 32 9.8 42 12.8 Note 1 Suggested ma".imum spacing between pipe supports for horizontal straight runs of standard and heavier pipe at maximum operating temperature of 750*F (400*C).
Note 2 Does not apply where span calculations are made or where there are concentrated loads between supports such as flanges, valves or specialties. l Note 3 The spacing is based on a fixed beam support with a bending stress not exceeding 2300 psi (15.86 MPa) and insulated pipe filled with water or the equivalent weight of steel pipe for steam, gas, or air serv.ce, and the l pitch of the line is such that a sag of 0.1 in. (2.5 mm) ;
between supports is permissible. l l
Ref. ASME B31.1-1989 Edition, Table 121.5 l
DRAFT 6-67 July 25, 1992 l l
i
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN EUIDE 6.2.3.3.3.2 Support Spacing l
Span lengths for lateral restraints, except those which restrain concentrated weights, may be increased up to two times the normal l
i gravity support distance.
l uateral restraints are most effective when placed near changes in r
direction at already existing gravity support positions. If unsure about exact lateral placement, these can be assumed at every l
gravity support location.
l l 6.2.3.3.3.3 Equipment Nozzles A lateral restraint should be assumed at the first gravity support from all equipment. ,
i I
6.2.3.3.4 Non-Seismically Supported Pipe Maximum gravity spans have been previously calculated using the equations for minimum deficction and stress requirements. The two equations are as follows:
For minimum deflection:
4 g,h 384EI(,1jngg)
(Eqn. 6.2-1)
Su l
For minimum stress:
4 8E (Eqn. 6.2-2)
L=h o (1500lbs/ inch 8)
Where: E = Young's Modulus (psi)
I = Moment of Inertia (in')
m (1bf/in)
Z == Section Weight per Unit Leng)th Modulus (in Table 6.2.3-2 shows maximum gravity support spacing with the limitations as noted on the chart.
l DRAFT 6-68 July 25, 1992 1
SYSTEN 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS-DESIGN GUIDE l 6.2.3.3.5 Leak-Before-Break Considerations See Section 7.1.9 and Appendix 7A for leak-before-break (LBD) considerations and analysis techniques.
6.2.3.4 pfne suonort criteria 6.2.3.4.1 Gang Supported Pipe The limitations for gang supports are analyzed piping equal to or 1ess than 8" NPS and 300'F. . Larger pipe sizes have higher loads making it impractical to design common supports.
6.2.3.4.2 Routing Gang Supported Pipe Pipes that are routed in close proximity to each_other should'be lined up vertically or have BOP elevations the same to allow the piping to be gang supported.
The largest piping should be closest to the wall with the smaller piping out into the room and at higher elevations. See section 6.2.5.2 for more-information on constructability and piping design.
Piping shoulo be routed close to structures which can be used for support attachment and group piping for common support.
Seismic and non-seismic piping interactions grouping should comply with the requirements outlined in Section 6.2.3.5.2.6.
6.2.3.5 Non-seismic Pioinq Non-seismic piping.has not been analyzed to withstand an earthquake and thus cannot be credited for operability during earthquake conditions. Note that while non-safety related piping is generally 6 non-seismic, it may be seismically supported to prevent adverse interactions with safety-related piping and equipment. ,
6.2.3.5.1 Routing Considerations The following routing consideration'should be'taken into account-when routing non-seismic piping.
A. Non-seismic piping should be separated from seismic piping to keep potential interactions - to a minimum. If the piping cannot be completely separated, it should be located as far apart as-possible.
B. - - Non-seismic piping should not be located above 'reismic components (i.e., piping, equipment, cable trays, ductwork).
DRAFT 6-69 July 25, 1992
~
SYSTEM 80+* DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN CUIDE i
C. Seismic piping should not be routed in areas where walls, stairwells, and other supports are not seismically supported.
D. Non-seismic piping should not be located above seismic valve operators.
E. Non-seismic piping, where possible, should not be routed in rocms containing safety-related equipment. When non-seismic piping is located in these areas, it should not be routed above the equipment.
6.2.3.5.2 Interaction Analysis The following are assumed failures as a result of a seismic event and should be used to determine the reaction of non-seismic pip'ing on other seismic components and structures. This criteria deals only with the physical effects of a non-seismic pipe falling.
6.2.3.5.2.1 Non-Seismic Cable Tray and HVAC Duct These guidelines deal with non-seismic piping int'eractions.
Failure of non-seismic cable trays, ductwork, and stairwells are not considered cut if there is a possibility of an interaction involving these components, they should be assumed to fail.
6.2.3.5.2.2 Hangers All non-seismic hangers should be assumed to fall instantaneously.
6.2.3.5.2.3 Mechanical Connections All flanges and bolted connections should be assumed to fail, allowing each se uion of piping to fall independently.
6.2.3.5.2.4 Rigid Constraint Welded piping should be assumed to fail at all rigidly constrained piping locations such as seismic structures, tanks, and equipment unless shown to be sufficiently supported.
Non-seismic piping which is supported by or within a seismic structure and is within the suggested pipe support spacing of Table 6.2.3-2 (Table 121.5 of ASME B31.1), should be considered to lose pressure boundary but not sever and fall. ,
All-cases outside of the limits of Table 6.2.3-2 should be assumed to fail, f
i DRAFT 6-70 July 25, 1992 1
-. . = _-_ . .. . _ _, ._. .-. -- _ _ -. _ __ __
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 6.2.3.5.2.5 Piping Area of Influence All moderate energy piping should be assumed to fall vertically downward from its original position. Side motion should be assumed
[ to be 6 inches (centerline to centerline) from the original pipe l
position. Pipe whip should be considered for high energy piping.
6.2.3.5.2.5.1 Arrest Safety-related piping equal to or greater than the diameter of non-seismic piping may be assumed to stop the downward motion of non-seismic piping.
6.2.3.5.2.6 Seismic /Non-Seismic Interaction
~
For seismic /non-seismic interfaces, the piping is assumed to fail
- in the non-seismic piping beyond the last seismically designed support. i I
6.2.3.5.3 Targets When non-seismic piping is routed in the area of safety-related equipment and seismic piping, all piping and equipment located below the non-seismic piping and within the assumptions of Section 6.2.3.5.2 are potential targets.
4 6.2.3.5.4 Damage Assessment i
No secondary interactions should be considered for damage assessment for muderate energy piping. Only primary interactions should be evaluated for damage.
6.2.3.5.4.1 Piping All non-seismic piping, two and one-half inch NPS and greater is capable of damaging other piping equal to or less than its diameter. Non-seismic piping, less than two and one-half inch NPS and greater than one-inch NPS, should not be considered capable of damaging any component except instrumentation devices and tubing,
! flex-hose, and unsupported cables. Non-seismic piping, one-inch NPS and less, should not be considered capable of damaging any component.
6.2.3.5.4.2 valves Valves without operators may be treated the same as piping.
6.2.3.5.4.3 Electrical Equipment and Instrumentation Cables in seismic cable trays should be assumed to be damaged by
! non-seismic piping greater than eight-inch NPS. Non-seismic piping between four and eight-inch NPS should be assumed to damage cables DRAFT 6-71 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE and cable trays if the piping conterline elevation is more than one foot above the cable tray top elevation.
6.2.3.5.4.4 Mechanical Equipment For purposes of evaluating impact effects on mechanical equipment ;
from piping interactions, four-inch NPS and greater piping should be considered capable of damaging mechanical equipment.
6.2.3.5.5 Protection 6.2.3.5.5.1 Pipe Rerouting Adverse interactions with non-seismic piping should be eliminated by rerouting the pipe if an acceptable alternate route can be found. Alternate routes should incorporate applicable pip'ing layout criteria.
6.2.3.5.5.2 Classification of Pipe Supports !
Supports for non-safety related piping may be upgraded to a seismic Category II classification. This upgrading includes the requirement that the piping be seismically supported in order to protect safety-related equipment and systems.
6.2.3.5.5.3 Deflector Shields Deflector shields may be designed around seismic systems to prevent interaction. These shields should protect the seismic equipment from any possible failure of non-seismic components. These shields should be designed and constructed to seismic standards.
f 6.2.3.5.5.4 Impact Analysis An analysis may be performed to estimate the amount of damage that i will occur when a non-seismic component fails. The impact load L should be analyzed from a conservative standpoint and damage potential determined. If no damage potential exists, no needs to be taken.
6.2.3.6 Hydrostatic Testina Provisions for Steam Pipina Gravity support provisions shall be provided for water filling of [
steam lines for hydrostatic testing. Any provisions that are only used for the testing (e.g., pinned hangers) should be specified to allow return to the normal configuration folloving the hydrostatic test.
i l
s l
DRAFT 6-72 July 25, 1992
SYSTEM 80+5 DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE 6.2.4 ALARA 6.2.4.1 General Incorporating ALARA principles in the design phase is essential to minimizing personnel radiation exposure over the life of the plant.
The following ALARA methods should be utilized in pipe routing.
A. Routing should minimize required operation and maintenance time in areas with high radiation levels.
B. Distance should be maximized between radiation sources and personnel during operations and maintenance.
C. Low points and dead leg crud traps should be minimized.
D. Adequate shielding should be provided.
E. Evaporators should not be used.
F. Piping containing highly radioactive liquids and gases should be routed in shielded pipe chases and trenches.
Implementation of these design methods is discussed further in the following sections.
6.2.4,2 Radioactive Pise Routinq 6.2.4.2.1 Radiation Zones / Personnel Areas During preliminary design, the plant is divided into several radiation zones. These zones indicate maximum dose rates based on normal operation of the station (i.e., location of high radioactive major components, personnel pathways, and period of human occupancy). Zone number designations can be found in CESSAR-DC, Table 12.3-1. Generally, zone designation numbers increase as the permissible level of occupancy decreases. These occupancy levels vary from continuous occupancy, as is the case for areas outside the plant, to infrequent occupancy around highly radioactive sources.
6.2.4.2.2 Fluid Radiation Intensity Radioactive piping differs in both degree of radioactivity and density. Routing considerations vary according to these i differences. The appropriate system description will aid in determining fluid density (gaseous, liquid, or slurry) . This information can be used with the following sections to determine proper routing considerations.
DRAFT 6-73 July 25, 1992 w-,-- ,- .-y w .- < - -
7 -
-s
SYSTEM 80+* DESIGN CERTIFICATION DISTRIDUTION SYSTEMS DESIGN GUIDE 6.2.4.2.2.1 Reactor Coolant Prior to Processing Reactor coolant fluid prior to processing contains fission and corrosion products generated by the reactor and associated piping.
This fluid can be liquid or gaseous. Liquids are later processed via degasification, demineralizers, filters and concentrators.
Gases are filtered and released through the unit vent.
6.2.4.2.2.1.1 Pipe Area Reactor coolant fluid prior to processing (both liquid and gaseous) should stay in the most infrequently occupied zone (Zone 5) but may enter the next lower zone (Zone 4) if its radiation level is within the limits of that zone.
6.2.4.2.2.1.2 Pipe Configuration Dead legs and lowered legs should be avoided in liquid lines because they collect radioactive particulates and thereby form localized " hot" spots in the system. Lowered legs are acceptable only when unavoidable and when lines are routed through inaccessible areas such as pipe chaces. Gaseous. lines are less prone to be crud traps.
Valves should be oriented to prevent crud accumulation and to allow drainage (liquid lines only).
6.2.4.2.2.2 Spent Resins Spent resins are slurries, usually of radioactive particulates and isotopes that have been processed out of reactor coolant fluid.
Resins are removed from the demineralizer during sluicing operations. Spent resins are typically the most radioactive of all fluids in the plant.
6.2.4.2.2.2.1 Pipe Area The layout of piping for spent resins should be confined to the most infrequently occupied areas of the plant (Zone - 5) . Any deviation of this layout consideration constitutes a potential radiation concern.
6.2.4.2.2.2.2 Pipe Configuration Because of the slurry nature of resin lines, traps for particalates should not be designed into the lines. Any further concentration would result in extreme levels of radioactivity, and possibly restrict flow sufficiently to require manual clean-out. Such a clean-out operation would expose personnel to an unnecessary radiation dose. Suggested practices to avoid such particulate traps in both radioactive and nonradioactive spent resin lines are listed below.
DRAFT 6-74 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIOUTION SYSTEMS DP. SIGN GUIDE A. The length of pipe run should be minimized; the most direct routing permitted by zones should be used.
B. The number of fittings should be minimized.
C. Low points and dead legs should be minimized.
D. Piping should be sloped in the direction of flow.
E. SD pipe bends should be used where practical.
F. Butt welds should be used instead of socket welds - socket weld applications should be specified.
G. Laterals should be used wherever possible/ if tees are unavoidable, orient branch above main run.
H. Cleanouts should be located every 20 feet except for straight pipe runs where wider spacing is acceptable.
I. When reducers are necessary, eccentric reducers with the flatside on the bottom should be used.
J. Valves should be oriented to prevent crud accumulation and to allow drainage. Refer to Section 6.2.2 for specific valve information.
Lowered legs should be avoided in .'1 radioactive piping. They allow the buildup of crud deposits, and thereby concentrate radiation. Lowered legs are acceptable only when unavoidable and when lines are routed through inaccessible areas such as pipe chases.
6.2.4.2.2.3 Diluted and Processed Fluid Diluted radioactive fluid consists of the liquid waste which is collected from the floor drains and valve stem leakoffs throughout the station. Processed fluid is reactor coolant downstream of the demineralizers and filters.
6.2.4.2.2.3.1 Pipe Area Diluted radioactive fluid and processed reactor coolant fluid should be confined to the most infrequently occupied zone (Zone 5) '
and tne first lower zone (Zone 4) but may pass through the second lower zone (Zone 3) if its radiation Aevel is within the limits for that zone.
6.2.4.2.2.3.2 Pipe Configuration Diluted and processed radioactive fluid requires no special configuration provisions.
b DRAFT 6-75 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE l
6.2.4.2.2.4 Concentrates l
During processing, reactor coolant is passed through a concentrator l which boils off water thereby concentrating particulates. '
Therefore, concentrate fluid is essentially concentrated reactor coolant and should be treated accordingly.
6.2.4.2.2.4.1 Pipe Area Concentrates should be confined to the most infrequently occupied ,
zone (Zone 5) of the plant. l 6.2.4.2.2.4.2 Pipe Configuration Dead legs shocid not be designed into concentrate lines, and clean-outs should be oriented so as not to form crud traps.
Valves should be oriented to prevent crud accumulation and to allow drainage. Refer to Section 6.2.2 for specific valve information.
6.2.4.2.2.5 Post-LOCA Fluid After a loss-of-coolant accident, a percentage of the radioactive isotopes present in the fuel rods are assumed to be released into !
the coolant. The assumed release percentages result in post-LOCA fluids being even more highly radioactive than spent resins-6.2.4.2.2.5.1 Pipe Area Post-LOCA fluid piping should be limited to areas inside containment. If maintaining the fluid insido containment is not possible, it should be located in inaccessible areas of the highest radiation zone classification. Refer to the post-LOCA zoning drawings in CESSAR-DC, Section 12.3 for permissible areas. Post-LOCA zone designations are contained in CESSAR-DC, Table 12.3-3.
6.2.4.2.2.5.2 Pipe Configuration The configuration constraints of Section 6.2.4.2.2.1.2 apply to post-LOCA piping.
6.2.4.2.3 Field Routing Pipe which is field routed has its layout determined by construction personnel. As such, field routed piping has very little design control of its layout. For this reason, field routed piping of potentially radioactive lines is prohibited. For specific considerations of field routed piping see Section 6.2.11.
I DRAFT 6-76 July 25, 1992 l
l
l SYSTEN-80+* DESIGW CERTIFICATION
- DISTRICUTION SYSTEMS DESIGN GUIDE i 1 l 3
! 6.2.4.3 Sleeve and openino Location i
I Scattering and streaming are two cases of radiation leaving a shielded area due to discontinuities in the shield wall. These factors should be considered in the sleeve design.
I 6.2.4.3.1 Sleeve Selection-4 I Sleeve selection into or out of a shielded area should be made with
- priority given to streaming. The sleeve should not be in a direct
- line with major radioactive components. This would give a direct ,
i path for radiation out of shielded arch. See Section 6.2.4.3.3 and l Figures 6.2. 4-1 and G.2. 4-2.
! 6.2.4.3.2 -Scattering Considerations ,
If streaming is properly designed for, then scattering will generally be insignificant. _The primary criteria, therefore, will _
be to design against streaming.
6.2.4.3.3- Streaming Considerations i Usual passages for streamed radiation are openings . to _ shielded -
. areas, unused sleeves, and any.open space between a-sleeve and what 4 it allows through the shield._ There are three considerations to avert streaming: See Figures 6.2.4-1 and 6.2.4K 4
A. All shield area openings should be labyrinthed so that there is no direct path-for radiation to follow out of the
- . shield area.
i B. Attention should be given to sleeve location. Sleeves
-should not' be placed in a direct - line with major l
radioactive components, as this could' allow-a. direct path for radiation to leave the shielded-area.
C. Close attention should be given to the usage of sleeves..
Spare sleevei- should be filled _ after the design and erection in a particular area, is complete, thus eliminating them from consideration.
I 6.2.4.4 General Plant Arranaement All hazardous radiation sources should be located in shielded areas. The primary consideration is to prevent any line of sight between normally accessed personnel areas.and radiation-sources.
l Specific considerations are described below.- .
i DRAFT 6-77 July 25,_-1992 l
L-
SYSTEM 80+* DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE FIGURE 6.2.4-1 Sleeve for Shielded Area Ar,, y Area Y
- .':0 -
Source 3
v, 2&4
$1de View
~~~~
l S O 'i I -s '
l / \ l 8
I l l l l 8~ l
- l-i l l
3 30 i l-l- i l I i 1 1 I 1 1
' 8 l 10 li l I I
i \ /
l N/
120 40 ,
Front View Penetration i 3 is an-improper location sinus it is in--direct line with the source and therefore results in excessive streaming.
DRAFT 6-78 July 2Sr 1992
SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE FIGURE 6.2.4-2 Radiation Streamina z
O W Pipe i
O kGamma Ray The above sketch shows " streaming" radiation through a doorway. Locations 1 and 2 indicate two possible areas where the pipe near the doorway could be relocated to reduce streaming.
DRAFT 6-79 July 25, 1992 i
1 l
SYSTEN 80+" DESIGN CERTIFICATION i DISTRICOTION SYSTEMS DESIGN GUIDE 6.2.4.4.1 Additional Shielding for High Radiation Components High radiation level components (i.e., ion exchangers, filters, tanks) require additional shielding. Shielded valve galleries should also be considered.
6.2.4.4.2 Labyrinths To prevent a line of sight between components in a shielded area and a personnel area, labyrinths should be used in the design of entrances to shielded areas.
4 6.2.4.4.3 Sleeves Sleeves should be placed through shield walls in such a location as to allow piping through the wall while minimizing streaming and scattering.
6.2.4.4.4 Isolation of Components Generally, to minimize personnel radiation exposure during operacions and maintenance, only one radioactive component should be located per room. When two components are located in the same room additional radiation barriers should be considered and located where practical. .
6.2.4.4.5 Pipe Chases Pipe chases should be provided such that piping serving radioactive components does not need to violate a radiation zone to reach the component.
6.2.4.4.6 Sampling Rooms Sampling areas should be separate from radioactive component rooms so that personnel can sample system fluids with a minimum _ of radiation exposure.
6.2.4.4.7 Curbing Around Tanks Containing Radioactive Liquid or Slurries Curbing should be placed around tanks containing radioactive liquid or slurries to prevent the spread of contamination in the event of a leak.
6.2.4.5 Maintenance Considerations Normal plant maintenance can constitute substantial personnel i radiation exposure. There are, however, design considerations that should be used to reduce this exposure.
l DFAFT 6-80 July 25, 1992
SYSTEM 804* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 6.2.4.5.1 Vendor-Specified Removal Space As a minimum, the vendor removal space dimension should be available at the component to be serviced. This ensures that the component can be disassembled for servicing. Any additional allowance for special tools should be used along with this removal space requirements (see Figure 6.2.4-3) .
6.2.4.5.2 Accessibility l
Components requiring maintenance should be easily accessible. This allows personnel to arrive and depart from the component quickly with minimum exposure. For this reason, maintenance components should never be located in radioactive pipe chases.
6.2.4.5.3 Equipment Separation in Compartments Piping runs with components that require servicing should be l separated from other radioactive piping.
6.2.4.5.4 Non-Radioactive Piping and Components Non-radioactive components requiring maintenance should not be located in areas containing radioactive components. This will allow personnel to maintain non-radioactive equipment without receiving unnecessary personnel radiation exposure.
i 6.2.4.5.5 Direct Drive Fans Direct drive fans should be used in areas of high radiation to minimize maintenance requirements and the resultant exposure.
6.2.4.6 Valve Shieldina 6.2.4.6.1 valve Galleries For high radiation components, valves should be located in shj elded valve galleries to allow valve operation and maintenance away from highly radioactive components.
6.2.4.6.2 Valve Operator Rooms Valve operator rooms may be used to separate radioactive component rooms and valve galleries so that valves remotely operated by reach rods can be manipulated with shielding between the valve operator and the radioactive valve (s) .
DRAFT 6-81 July 25, 1992
SYSTEM 800* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE FIGURE 6. 2. 4-3 Valve Pull Space Adequate space should be provided to remove the topworks (bonnet, yoke, stem) from the valve and perform necessary repairs.
P n
D 5
8 eU m
- =
8 L . _ .
S V
,j=~\,,
'%#n ii r DRAFT 6<32 July 25, 1992
- . - . - - . _ . .- _-_ .- - _- ~ _ - - .
1 SYSTEM 80+* DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE 6.2.4.6.3 Remote Valve Operators Remote valve operators may also be used to minimi: personnel exposure. However, valve operator maintenance should t snsidered along with the radiation effects on elastomers and it- ants in the valve operator.
6.2.4.7 Mechanical comeonents All components which process radioactive fluids (gas or liquid) can i pose a radiation hazard. Specific considerations are described below.
6.2.4.7.1 Pumps Pumps are generally a small radiation source. However, pumps 'are
} a high maintenance item, and therefore, could contribute i
significantly to the total station dose. The following i*. ems should be considered in order to minimize the dose rate.
6.2.4.7.1.1 Low Points
- Low points should be minimized in suction lines for two reasons.
Fi r s '. , low points tend to collect radioactive particulates.
i Second, suction lines cannot be drained during operation. These combine to make suction line low points potential crud collectors.
6.2.4.7.1.2 Leakage
- Leakage of pumpe seals should be accounted for along with the conditions of pump drains.
! 6.2.4.7.2 Heat Exchangers Heat exchangers associated with radioactive systems are susceptible to crud plateout on the tube side, leading to radiation concentration. There is also the possibility of tube leakage, which would contaminate otherwise nonradioactive systems. Heat exchangers should be designed to reduce maintenance exposure by providing flushing and draining provis: ions and making the radioactive fluid the lower pressure fluid. They should also be separated or shielded from high maintenance items.
I 6.2.4.7.3 Demineralizers Demineralizers remove radioactive source materials by absorbing them into a resin bed. Periodically, this resin is sluiced out and replaced. Because demineralizers concentrate radioactive source materials, they represent a substantial re.diation exposure source.
Exposure during operation and maintenance should be minimized by placing valves, motors, switches, and other items outside i demineralizer equipment rooms or behind shielded partitions.
DRAFT 6-83 July 25, 1992 l
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 6.2.4.7.4 Tanks Tanks associated with radioactive systems contain large volumes of radioactive fluids. While the fluids themselves may not be highly radioactive, the large volume, and any crud in the liquid, make thh tank a radiation source. Streaming and scattering usually represent the primary exposure potential in these rooms. The design should consider serviceability in the same manner as demineralizers.
Curbs should also be placed around tanka containing radioactive fluid to minimize the spread of contamination in the event of a leak.
6.2.4.7.5 Concentrators Concentrators separate radioactive particulates from reactor coolant water and concentrate them. As such they represent varying degrees of radiation exposure potential. As these components are often skid mounted, care should be taken to locate valves and other maintenance items away from the " hot" side of the skid.
6.2.4.7.6 Strainers Strainers present a potential radiation source as they remove relatively large chunks of material from the fluid and may warrant shielding. The design should consider serviceability in the same manner as demineralizers.
6.2.4.7.7 Filters Filters remove m'oderate size particulates from the fluid, thereby concentrating radiation. Filters, therefore, represent a radiation 3 hazard. The design should consider serviceability in the same manner as demineralizers.
6.2.4.7.8 Valves Valves should be located and oriented to minimize the potential of crud traps. Some valve types are more prone to be crud traps and should be considered in the valve selection. Care should be exercised to avoid placing valves near any highly radioactive component. They should be in valve galleries whenever possible or in areas of lower radiation dose rate and accessible for maintenance. For more information of valve orientation to avoid crud traps and facilitate drainage as well as valve descriptions, see Section 6.2.2.
DRAFT 6-84 July 25, 1992
f SYSTEN 80+5 DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE 6.2.4.8 Protectiqn ,
6.2.4.8.1 Pipe Rerouting Pipe rerouting may be required as the design progresses to satisfy ;
sometimes conflicting design considerations (see Section 6.2.4.2). l From a purely economic viewpoint, rerouting during the design <
process is generally the preferred method to minimize radioactive pipe routing concerns. Other methods should be considered as second alternatives. Rerouting may be required for any of the following reasons.
6.2.4.8.1.1 Radiation Zone Violations Several rerouting methods are possible for radiation zone violations, each depencing on the degree of violation.
A. Increase Separation Distance -
For cases where the radiation dose rate at the nearest personne.' path is only slightly higher than the allowable rate fur the zone in question, an acceptable method is to increase. the ,
separation distance from the source to the personnel path.
This can be accomplished by raising or otherwise relocating the pipe within the zone.
B. Reroute Through Higher Zone - For cases where the radiation dose rate of the pipe in question is much higher than the zone it is routed through, or it is not possible to provide sufficient separation distance, rerouting the pipe through a higher zone is the preferred method. l 6.2.4.8.1.2 Streaming Streaming can be minimized by routing pipe such that ' streaming from large components cannot occur. This involves rerouting pipe-and-locating sleeves so that there is no direct line from a component through the shield wall.
6.2.4.8.1.3 Crud Traps Rerouting of pipe to eliminate crud traps can be accomplished by revising layouts to satisfy the guidelines of Section 6.2.4.2.2.2.2.
6.2.4.8.2 Wall Construction or Relocation The - construction of a wall ~ solely. to contain- radiation- -is - a -
possible' method to increase radiation-shielding.. -Itris, however, usually not practical unless all rerouting possibilities have been-exhausted. -If the va21 has not yetLbeen erected, .the consequences-of relocating the wa' ec 1.essened and could be more feasible .than relocating the pipe DRAFT 6-85 July 25, 1992 4
..,+--w_.,,-ae, e--,--
SYSTEM 80+5 DESIGN CERTIFICT. TION -
DISTRICUTION SYSTEMS DESIGN GUID5 6.2.4.8.3 Lead Shielding Construction of a lead -' shield to contain radiation is another possible shielding metht Th: 1 method should only be considered when rerouting of the piping is not practical.
6.2.5 CONSTRUCTABILITY 6.2.5.1 Standard comoonents Standard components should be used to the maximum extent possible for piping, fittings, valves, and supports (see Section 6.1.4.2). ,
6.2.5.2 Pipe Assembly 6.2.5.2.1 Banked Fiping Assemblies s The requirements for the location of. piping assemblies in banked piping differs for seismic and non-seismic. For specific guidelines on banked piping with analyzed piping and gang supported piping interactions, refer to Section 6.2.3.4.
6.2.5.2.1.1 Field-Routed Piping For field-routed piping, field personnel prefer the largest pipe to be closest to the wall with the smaller pipe out into the room and at a higher elevation. See Figure 6.2.5-1 for the preferred location of the piping arrangement and Section 6.2.3 for support requir'ments.
6.2.5.2.1.2 Piping in Trenches Stacking of pipe in a horizontal trench should be done from the bottom to the cop beginning at the wall. The center of the trench should be left open to provide access to piping toward the walls.
Clearance from walls, ceilings and ficors should be at least 12 inches for purposes of construction, maintenance and inspecti'tb For inservice inspection considerations for-piping in trenches, see Section 6.2.6.5 and Figure 6.2.5-2, 6.2.5.2.1.3 Elevations The bottom elevation of non-seismic piping should be kept the same to facilitate the use of common hanger steel when running banks of piping (see Figure 6.2.5-3) . See Section 6.2.3.4 for pipe routing for supportability.
=
DRAFT 6-86 July 25, 1992
_ - _ _ . - _ _ _ - _ _ _i
4
- ' ~
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE FIGUBE.6.2.5'-1 i
j Field Routino Conficuration i
i i
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- I S.
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a i , , , ,
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2
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s d
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WALL T* ,
i 4-i 9 i
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+
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SM ALLER, f,r . ' . ,
g t i s- ! L .
>.t* T, -
f +I i
+
I t .' ' .
. . V. ,
i NON-ANALYZED OR FIELD ROUTED CONFIGURATION i
DRAFT 6-87 July 25,'1992
- . . - - - . . - . . . - . . - . . - . . . - . - . . .- -. .. .n SYSTEM C0+5 DESIGN CERTIFICATION-DISTRIBUTION SYSTEMS DESIGN GUIDE--
FIGURE 6.2.5-2 Pine Trench Conficuration Section in center of trench should be left-open to allow access, i
y
! -q> & 6 e, - f l t (
4 . , 3 - b4 P M t ,
b
.Y \'
t 3 h 5- 2 FEET.- -
A MINIMUM , a-I ~
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LARGER PIPE TOWARD WALL DRAFT 6-88 July 25, 1992 l
. . - - m s- ... , . . _ . . , , , , - ,e. ., . ,.J-,,
< 1 i
i ,
SYSTEM 80+" DESIGN C3TIFICATION- l DISTRIBUTION SYSTEMS DESIGN GUIDE 4
FIGURE 6.2.5-3 i
- Common Succort Configurati a i
l 4
, outside diameter of pipe should have common bottom elevation to allow use of h
- common pipe support.
l Wh
{ 8"%
4 6' 3* h l i
1 i
(+:)
6-l h
1-i
! COMMON PIPE SUPPORT l l
i i
i DRAFT 6-89 July 25, 1992 i
- SYSTEM 80+;" DESIGN CERTIFICATION DISTRICUTION-SYSTEMS DESIGN GUIDE e.2.5.2.2 Pip'e-Bends 6.2.5.2.2.1 Radius Bends When ' designing long - radius bends, as in the Reactor - Building, 1 branches from the long radius bend to another 3DLor SD bend ~should-be avoided. These branches are very difficult'to'fabricatt.;A teel should be installed .in a tangent'. area- with the' bratwh L bend '
connected to the tee branch.-
6.2.5.2.2.2 Sloped Piping If a piping system requires a slope, the slope may be obtained if butt welds or socket welds are used. Specific slope considerations
.for socket welds and butt welds are as described below._ .
6.2.5.2.2.2.1 Socket-Weld Piping I
Due to the geometry of a socket weld fitting, there is enough play between the pipe'and fitting soLthat the pipe.can be welded ~into the fitting at an angle. If a greater' slope is -: required, - the -
inside of the fitting. ma:' be ground to 87.5% of ~ the ? nominal wall
. thickness. This will allow-the. pipe to be welded at a greater-angle. When a slops is required, which cannot be obtained.byLoca of the above methods, the piping-may require a-bend.
6.2.5.2.2.2.2 Butt Weld Piping Fittings for butt weld pipe may be mitered in order.to obtained a slope in the pipe. The fit-up-gap for'the backing ring bevel gap
, in butt weld pipe may be maneuvered within tolerances to obtain_a sloped pipe.
6.2.5.2.2.2.3 Arced Piping Arced piping _ should not be additionally . sloped. This requires forming a 2-plane bend, which~is beyond the_ capabilities of-field personnel, and also increases the radius of the Doriginal arced pipe.
.6.2.5.2.2.3 Bend Constraints 6.2.5.2.2.3.1 Bend Clearances-Fittings, equipment, and connections should not be placed within-six inches of.the tangent to the bend radius (see- Figure 6.2.5-4):.
'6.2~5.2.2.3.2
. Bend Deflection
-Bends should not be specified unless the maximum deflection . is greater than one-inch, which is generally _the tolerance for field DRAFT 6-90 July _25, 1992
i J
l SYSTEM 80+* DESIGN CERTIFICATION
- DISTRIBUTION SYSTEMS DESIGN GUIDE
! personnel _to form theses bends. Table 6.2.5-1 lists the radius of-
- a bend and the angle where the deflection becomes one inch.
6.2.5.3 Construction Assembly ,
- 6.2.5.3.1 Layout 6.2.5.3.1.1 Fitting-to-Fitting Restrictions From a field f abrication stand, oint, fitting-to-fitting connections
! should be eliminated since they do not allow any adjustment during-I fit-up. This is especially true when the piping passes-through a l wall or floor (See Figure 6.2.5-5).
l The following restrictions apply to fitting-to-fitting connections:
t i
A. Elbows should only be connected to _ spool pieces, other i elbows, or reducers.
! B. . Reductions in line size ~of 4:1 or more should be done-in
- at least-two steps with spool pieces-in between.
I C. ASME Class 1, 2, and 3 piping should'have a spool piece
! between all fittings with_a minimum length-of 6 inches.
i
! 6.2.5.3.1.2 Spool Pieces ,
6.2.5.3.1.2.1 Construction Fit-up
- Piping layout should include a large enough spool piece to allow
- for: (1) adjustment during fit-up, especially in o the case of equipment hook-ups, (2) flexibility to adjust for thermal growth,
! and (3) construction tolerances (see Figure 6.2.5-6) .
6.2.5.3.1.2.2 Minimum Spool Pieces The following should have'a 6" minimum spool piece:
A. Piping discontinuities (see Section 6.2. 6.4) .
l B. Fitting-to-fitting or fitting-to-component configurations -
(see Section' 6.2.3.1.3) .
See - Figure
~
~
C. Adjacent - valves to serve as a weld safe.
n 6.2.5-7'and Section 6.'2.6.4.
D. Traceability informat' ion and overlapping of fillet welds on socket weld pipe (see Figure - 6.2.5-8) . .
l A minimum 6" spool piece should be used for small' diameter pipe (6" NPS or less) and a 6" to 12"* minimum spool piece for NPS larger than 6".
DRAFT 6-91 July 25,T1992 I
l
. _ . - - . - . - - . . - . . _ - . ~ . . . .
. . - . - - . . - . . . ~ , - - . ..
4 I
~
SYSTEN 80+" DESIGN CERTIFICATION--
i-DISTRICUTION. SYSTEMS' DESIGN GUIDE L
- f. TABLE 6.2.5-1 Bend Radius l
R S 0 120' (1440") 9' -0 " 4.3* >
a j 115' (1380") 8 ' -10 " 4.4' 110' (1320") 8'-8" 4.5'- Deflection ='1"
! 105' (1260") 8 ' -5 " 4.6' s >
! 100' (1200")- 8 ' -2 " 4.7' l 95' (1140") 8 ' -0 " 4.8* .
1 t 90' .(1080") 7'-8" -4.9*
R R
< 85' (1020") 7'-7" 5.1*
! 80' ( 960") 7'-3" 5.2' 75' ( 900") 7'-1" 5.4*
l j 70' ( 840") 6 ' -10 " 5.6' 6 ' -7 " 5.8' 8' l 65' ( 780")
i:
3 60' (-720") 6 ' -3 " - 6.0*
! 55' ( 660") 6' -1 " 6.3*
1- 50' ( 600") S'-9" 6.6*-
4 45' (-540") 5'-6" 7 .'0
- R = Radius i
40' ( 480") 5'-2" 7.4' .0 = Angle 1
,1,
-l .
j g p 1" f
- f. 3 E _ a DEFLECTION-< 1" i- -
BEND DOES NOT NEED-TO BE1 SPECIFIED l
[
- I 2
-c h
J DRAFT 6-92 July 25, 1992 n
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i SYSTEM 80+" DESIGN-CERTIFICATION' DISTRIBUTION SYSTEMS DESIGN CUIDE' l 1 l 1
, FIGURE-6.2.5-4 0 Bend Clearances I
4 4
- TANGENT 4
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l 6" SPOOL l
l l t
. TANGENT E
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l 6" SPOOL i %
i I
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.t 4
1 J
DRAFT 6-93 July 25, 1992
~
SYSTEN 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTFMS DESIGN GUIDE.
FIGURE 6.2.5-5:
Non-preferred Sleeve Confiauration-
+ .
b,, - ,
- a i
- MISSED-SLEEVE
-l FITTING-TO-FITTING.
l LEAVES =NO' ROOM FOR ADJUSTMENT T ,
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-l 6-94 July 25, 1992 DRAFT
-- .. - . _ .a
.- . . - - .. . . . ~ . . . . . - . _ = . . . - - . ... - . . . . . . . . -
r 'SYSTEN 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE i
FIGURE 6.2.5-6 UP-Ecuioment Fit-up li g N
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DRAFT 6-95 July 25, 1992
-w .-m -..w,, ..w., w,,, , .a...- s , w - ,,nug
- w.,-o
SYSTEM 80+5 DESIGN CERTIFICATION DISTRIDUTION SYSTEMS DESIGN GUIDE l
FIGURE 6.2.5-7 Spool Piece Between Valves l j l
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8 o
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DRAFT 6-96 July 25, 1992
! l 4-a SYSTEM 80+" DESIGN' CERTIFICATION
. DISTRIBUTION SYSTEMS DESIGN GUIDE i FIGURE 6.2.5-8 3
Traceability Information l
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--l-I INFORMATION ~~'~*l-"" f 4 I V
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e MINIMUM 6" SPOOL PIECE i
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DRAFT 6-97 July 25, 1992 i-
l SYSTEM 80+"' DESIGN CERTIFICATION j DISTRIBUTION SYSTEMS DESIGN GUIDE I
6.2.5.3.2 Equipment 6.2.5.3.2.1 Equipment End Connections All valve and equipment connections should be checked against the manuf acturer's drawing to ensure that the nozzle is of the same schedule as the pipe and the same type of connection (flange, butt weld, socket weld). A transition piece should be provided if necessary.
6.2.5.3.3 Tolerances Tolerances should provide adequate flexibility for field installation. Spool pieces in three directions are a method to prevent tolerances from being overly restrictive (see Figure 6.2.5-7) 6.2.5.3.4 Weld Types 6.2.5.3.4.1 Field Welding Provisions Field welding is performed under less controlled conditions than shop welds. Adequate fit-up tolerances should be provided so as to not make erection overly restrictive, thus requiring excessive field changes.
6.2.5.3.4 2 Minimize Field Welds Due to the less controlled conditions for field welding, field welds should be minimized where possible.
6.2.5.3.4.3 Butt Welds Butt welds are standard in piping greater than 2" NPS, but may be used in smaller piping where there is the potential for crud buildup. The minimum size for butt welds should be 1" (see Section l 6.2.4.2.2.2).
6.2.5.3.5 Insulation Allowances Allowances should be provided for insulation. For removable insulation (reflective, blanket), access and clearance should also be adequate for insulation removal and replacement. Additional clearance should also be provided to prevent contact of adjoining piping and insulation under maximum allowable thermal movement.
6.2.5.4 Accessibility for Construction 6.2.5.4.1 Clearance A. Adequate clearance should be given at all points for welding, inspection, testing and maintenance. Typically, DRAFT 6-98 July 25, 1992
.- _ . . - . - .-- - . - . - . . - - . . . = = .- -. - . - . - - . . . -
L i SYSTEM-80+5 DESIGN CERTIFICATION l DISTRIBUTION SYSTEMS DESIGN GUIDE at least 12" of clearance.is needed from walls, floors, and ceilings. For seismic piping, a clearance of at least
'18" should be left for installing s'nubbers. If _ the ' piping i is = ASME Class 1, 2, or ' 3, Section-- 6. 2. 6. 3 gives the-minimum clearances. For piping __ support -considerations, l see_Section 6.2.3.1.2 for clearances.
4 B. When locating equipment,-the needed for installing studs and flanges around equipment should be considered.
]
i C. An envelope should be left around piping and structures,
- depending on diameters, for the installation of i insulation.
1 6.2.5.4.2 Flanges l ,
i A. Flange connections should be used for all high maintenance
! equipment for . easy removal. All connections to the i equipment should-be flanged, not'just major connections.
j - Equipment with lower maintenance priority may have welded i connections.
l i B. When flanging equipment _-that is frequently disassembled, l laydown consequences should be considered. Flanges should t be placed so as to permit the part to be laid down _without j ' damaging the piping or equipment- (see Figure 6.2.5-9) .
6.2.5.4.3 Valves / Isolation e
j When designing piping and locating valves, the orientation of the a valve and space required for installation,: operation, and l maintenance should be _ considered .(see Section 6.2.2) .
i 6.2.5.4.4 Door Swing Space j When_ designing piping in the area of control cabinets, door swing
- space should be considered.
6.2.5.4.5 Testing Provisions-l_ Testing provisions are described in Section 6.2.'7.
6 . 2 . 5 . '4 . 6 - Inspection Provisions Inspection provisions are described in Section-6.2.6.
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!- . DRAFT 6-99 July-25, 1992 9
ti .
4
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- -SYSTEN 80+" DESIGN CERTIFICKfION DISTRICUTION SYSTEMS DESIGN GUIDE-i d
o l
FIGURE s. .2.5-9 Flance Confiouration f
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l' j l j g 3 FLANGE SHOULD BE PLACED I
l ABOVE SEPARATION f
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l 1 SEPARATION
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-DRAFT- 6-100 July 25, 1992
. . ,_ . _ . 2, _a_, - _.. . . _ . . . _ . . . . . . , _ _ . _ . _ . _ . - . . . . _ . . . . . _ - _ . . _ _ _ _ ..._ . . _ .... _ . - , _ . . .
SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 6.2.6 ACCESSIBILITY FOR INSERVICE INSPECTION Inservice inspection (ISI) involves four main examination procedures: (1) visual examinations, (2) surface examinations, (3) volumetric examinations and (4) pressure testing. Most ASME Class 1 and 2 components require a combination of the four types of inspection, while Class 3 components require only visual and pressure examinations. This also includes preservice inspections (PSI) prior to placing the system in service.
In order to perform inservice inspection, the layout and design of the piping should provide adequate access to the various ASME Class 1, 2, and 3 components. This section describes minimum spacing requirements needed to perform inservice inspection.
6.2.6.1 Cle a ra n c- For Insoection Ecuipment Provision for placement of inspection equipment should be provided for all ASME Class 1, 2, and 3 piping.
6.2.6.2 Parallel Pipe Scacino For ASME Class 1, 2, and 3 piping, the piping design and layout should provide the following clearance between pipesi A. For piping (including necessary insulation) with an OD of 9 inches or less, an minimum envelope of (1.33 x OD) should be left around the pipe, separating it from parallel piping. For ease in design calculations, 1.5 (OD) is an acceptable design value (see Figure 6.2.6-1).
B. For piping (including necessary insulation) with an OD greater than 9 inches, a 12 inch parallel spacing requirement should be used. Additionally, a 2 foot square area should be maintained above and below the piping for visual inspection.
C. The separation requirements for the larger line including necessary insulation should be used when different line l sizes are run parallel.
6.2.6.3 Structural Clearance The minimum allowable distance from floors, ceilings, and walls for piping should be in accordance with the values given in Table 6.2.6-1. This piping may or may not contain insulation. The minimum distance designated here will be free space between the structure and the outside of the piping = insulation. See Section l 6.2.3 on support / restraint requirements.
DRAFT 6-101 July 25, 1992
SYSTEM 80+5 DESIGN CERTIFICATION DISTRIEUTION SYSTEMS DESIGN GUIDE
~
6.2.6.4 Discontinuities The following requirements apply to all ASME-Class 1, 2, and 3 piping in order to meet inspection _ requirements.
Piping discontinuities are items that break-up linear runs ; of piping, such as tees, elbows, valves, and other fittings. These-discontinuities should not be- joined directly together. _There should be a minimum spacing of six inches _ between discontinuities.
This space allows'a clear sound path for ultrasonic inspection of the joining welds. Support requirements and _ constructability requirements also necessitate this six-inch minimum spacing. Note that not all fitting-to-fitting designs are undesirable; however, for ASME Class li 2, -and _3 piping, no fitting-to-fitting configurations should be used. Examples _of spacing requirements for several piping discontinuities are.given-in Figure 6.2.6-2.
6.2.6.5 Pipe Chases and Trenches In horizontal and vertical pipe ch'ases, the piping layout should be in accordance 'with constructability requirements as provided;in Section 6.2.5.2.1.2. Only ASME Class 2 and-3 piping should be-placed in chases and trenches;- Class 1 piping should i not be located in chases-or trenches.
6.2.6.5.1 Horizontal Pipe Chase Class 2 and 3 piping should be run in the lower third of horizontal pipe chases and near the access aisle to -allow for inservice inspection. The spacing requirements of Section 6.2.6.2 should be met, except where other criteria (i.e., interactions or support /
restraints) will affect them. Access aisle width should be at '
least 3 feet (see Figure 6.2.6-3).
6.2.6.5.2 Vertical Pipe Chase ASME Class 2 and 3 piping should be run in cl-ose proximity to the ladder provided . for access. The pipe spacing requirements of Section 6.2. 6.2 should be met. See Figure 6.2.6-4 for allowable zones. Access around the ladder should be 3 feet.
6.2.6.5.3 Trenches ASME Class 2 and 3 piping should be run in the top third of the trench with priority to accessibility.given to Class 2 piping.-
Section 6.2.6.2 spacing requirements-oniv apply-for. Class 2 piping as Class 3 piping can_be pressure tested in theJtrenches. The.
access area should be 3 feet in width (see Figure 6.2. 6-5) .
DRAFT 6-102 July 25, 1992
. SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE TABLE 6.2.6-1 Minimum Structural Clearance
/t INSULATION CEILING IF NECESSARY f a b WALL
- FLOOR 56.
NL PIPE OD INCLUDING CLASS 1 AND 2 CLASS 3 INSULATION PIPING "X" (In) PIPING "X" (In) 1" 12" 12" 2" 12" 12" 3" 12" 12" 4" 12" 12"
- 5" 12" 12" 6" 12" 12" 8" 12" 12" 10" 14" 12" 12" 18" 12" 14" 18" 14" 16" 18" 16" 18" 18" 16" 20" 18" 16" 2 24" 18" 18"
- Non-standard pipe size.
DRAFT 6-103 July 25, 1992 l
l
f -
SYSTEM 80+5 DESIGN CERTIFICATION j
DISTRIBUTION SYSTEMS DESIGN GUIDE b
! FIGURE 6.2.6-1
' 8 l
Parallel Pipe Spacinq g t' A 4 M; 1
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, l.33 (QQ) _ ~
_ l.33 (O.D.) _ '
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24" 24" MINIMUM l
i VERTICAL SPACING FOR l
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- i mifMI m l2 Mig! '
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DISSIMILAR PIPE SIZES N
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USE SPACING REQUIREMENTS FOR PIPE WITH LARGER OD 1
Note: Outside diameter includes insulation.
6-104 July 25, 1992 DRAFT I
l
. SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE FIGURE 6.2,6-2
-Pipino Discontinuities 7 ~~B f """)
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SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN CUIDE FIGURE 6.2.6-3 Preferred Horizontal Chase Area ALLOWABLE AREA FOR CLASS '2 OR 3 PIPING-ACCESS AISLE LOWER N THIRD
.-- 3 '--.
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FIGURE 6.2.6-4 4
Preferred V?rtical Chase Area ALLOWABLE AREA FOR CLASS 2-OR 3 PIPING A
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\U\\Y DRAFT 6-106 July 25, 1992
~
SYSTEM ~80+" DESIGN-CERTIFICATION
, DISTRIQUTION SYSTEMS DESIGN GUIDE FIGURE 6.2.6-5 l
i Lieferred Trench Area-i --FLOOR OR
. GROUND D
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. ALLOWABLE AREA FOR CLASS _. 2 -
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l 6-107 DRAFT July 25, 1992-
SYSTEM 80+* DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE 6.2.6.6 Insulation Proper design of component insulation can greatly improve the esse and time requi. red for inspection. Where used, reflective insulation should be designed for ease of removal and replacement to allow access to welds in order to meet ALARA standards.
6.2.6.7 Guard Pipe Interference.
At present, there are no inservice inspection requirements for guard pipe; however, the guard pipe should not prohibit access to the process piping. Figure 6.2.6-6 illustrates inspection requirements for a ASME Class 1, 2, or 3 process pipe enclosed in a guard pipe.
6.2.6.8 Penetrations 6.2.6.8.1 Containment Penetrations The containment isolation valves-should be located no closer than six inches to the containment penetrations.
The ability to inservice incpect containment penetration piping is a function of penetration design. The attachment- welds to the penetrations should be inspected and therefore should be accessible. See Figure 6.2.6-7 for an example of containment penetration weld access.
6.2.6.8.2 Wal. and Sleeve Requirements Where it is necessary to run piping through walls, welds should be avoided adjacent to and within wall sleeves. Access should be provided for a distance of at least 3t (t = pipe wall thickness) and a minimum of 6 inches on either side of the weld. Where system requirements dictate a weld adjacent to or. within a wall penetration, an annulus of at least 6 inches around the pipe should l be provided. In all cases, the annulus should provide at least a l 30' projection # rom the weld centerline to the containment barrier.
Supports for piping at penetrations should also consider inspection accessibility. Supportability of the items such as in Figure 6.2.6-8 is also necessary, therefore, the use of removable supports may be warranted in order to provide accessibility to these areas.
6.2.7 TESTING PROVISIONS Testing includes both preservice (i.e., hydrostatic and operability testing) and periodic inservice testing (IST). Provisions should l be provided in the design and routing to allow this testing. These l provisions include bypass lines / valves, isolation valves, drains, and vents, as described below.
DRAFT 6-108 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE FIGURE 6.2.6-6 Guard Pipe deauirements for Inservice insoection ACCESSIBILITY FOR SURFACE EXAMINATION l
f, 7 _ _ _ ._ _ _ ._. _ ._ __ __ A
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I~~ l~ GUARD PIPE SHOULD BE DESIGNED TO ALLOW VOLUMETRIC WELD l
l INSPECTION. ACCESSIBILITY CAN i l BE ACHIEVEC BY HANDHOLES, l INSPECTION PORTS, OR REMOVABLE l
l SECTIONS OF GUARD PIPE.
I
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Vl O F REQUIRED 8v i
DRAFT 6-109 Jul'/ 25, 1992
-)
' SYSTEM!80+" DESIGN CERTIFICATION 'l DISTRICUTION' SYSTEMS-DESIGN CUIDE l 1
l FIGURE 6.2.6-7. -.
Containment Penetration Weld Areas-LAYOUT-COMPLIANCE REVIEW FOR WELDS- '
s PENETRATION - s DESIGN
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DRAFT 6-110 July 25,- 1992
-.--y.,nh.., c_,_.,,,;,.,-
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SYSTEM.80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE FIGURE 6.2.6-8 Access for Walls and Sleeves i.
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SEE SECTION 6.2.6.8.2 em a4 Ns. f *' .
p av 6" MINIMUM
( 0 0 )
l WELD CENTERLINE y .- %.).%
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N DRAFT 6-111 July 25, 1992.
l
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SYSTEM 80+" DESIGN CERTIFICATION DISTRIEUTION SYSTEMS DESIGN GUIDE 6.2.7.1 -Preservice Testino Preservice testing is' performed prior-to the system being placed in service to ensure system-design-requirements are thet. Preservice testing requirements are governed by the applicable piping code:
ASME Boiler and Pressure Vessel Code for ASME Class 1, 2, and 3 piping; and ASME B31.1 for non-safety related pipine;.
6.2.7.1.1 Hydrostatic Testing Prior to being placed in service, hydrostatic cesting of the piping systam is required per the applicable piping code. -This testing requires filling the system with water, pressurizing to greater-than the maximum operating pressure, and checking the system for leaks at welds, flanges, and other seams. The following provisions are required to perform'this-testing.
6.2.7.1.1.1 High Point Vents To allow filling of the system with water, high point vents are required. These connections may also be-used-to provide venting-capability during the hydrostatic test. These vents may also be used when refilling the system following maintenance.
6.2.7.1.1.2 Low Point-Drains Low point drains are primarily used- for system draining and flushing for maintenance, but may also-be used for the hydrostatic pump connection.
6.2.7.1.1.3 Instrumentation As a minimum, pressure instrumentation is required during the hydrostatic test. For hydrostatic testing of-isolated sections of the system, instrumentation testing connections-may be used.
6.2.7.1.1.4 Isolation Isolation capability is required to set the . testing boundaries using valves, blank flanges, and othE.r isolation metho'ds .
6.2.7.1.1.5 Steam Piping The water filling of steam piping imposes a larger than . normel gravity load on the piping and supports. This additional loading shall be considered in the design and could warrant 1 features such as temporary supports, and pinned hangers.
6.2.7.1.2 -Operability Testing Operability testing ensures that- the. system will perform as designed. Primarily, instrumentation,is required to verify system DRAFT 6-112 July 25, 1992
SYSTEN 80+* DESIGN' CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE parameters such as= flow and-cooling. Testing connections may_be used for-temporary _ instrumentation. requirements. -
6.2.7.1.3 Inservice' Testing _
Periodic inservice testing (IST) is required for ASME Class-'1,: 2, and 3-_ components in accordance with ASME Boiler and Pressure Vessel Code,Section XI . Prc visions for required IST should be considered throughout the design'and routing, as described below.
6.2.7.1.3.1 Bypass / Iso'.ation Capability Some IST is required curing plant._ operation'and requires isolation and/or bypassing the component to be tested. - These provisions include testing stations, and close_ proximity valve / component operations wherever ' practical. ..These provisions should ~ support ALARA goals and minimize / eliminate technical -specification-challenges by minimizing the number, and . the time required - with components non-operable to perform _the testing.
6.2.7.1.3.2 Full-Flow Pump Testing-A System 80+ design goal _is to-provide full-flow test capability _
for all ASME Class'1, 2 , and 3 pumps.- Proper system design (bypass lines, isolation. valves, etc.L and routing are required to meet this goal.
6 . 2 . 7 .1.' 3 . 3 Instrumentation Adequate instrumentation and its proper placement are required to monitor IST parameters such as pump flow and pump differential pressure.
6.2.7.1.3.4- Accessibility Accessibility should be provided for required IST. This access is needed_ to perform valve lineups, place _ test -equipment, -and instrumentation monitoring.
6.2.8 EROSION / CORROSION PIPE WALL THINNING PROVISIONS Erosion / corrosion. wall thinning of-carbon steel piping _has' caused.
extensiv_e piping rep.1acements and unplanned > shutdowns.at existing-nuclear power plants.- In-addition'to the material selectioneandi piping schedule (see.Section 4.2.1.3.5.2),- proper pipe routing is vital to minimize: pipe wall thinning degradation'.
l DRAFT 6-113 July 25, 1992- j
'l 1
- l
_ _ _ _ . _ . _ _ _ _ . _ . _ _ _ _j 4
SYSTEN 80+" DESIGN CERTI.TICATION l DISTRICUTION SYSTEMS DESIGN GUID3 6.2.8.1 Routino Guidelinet .
6.2.8.1.1 Dry Steam Pipe Routing Guidelines ;
Erosion / corrosion wall thinning of steam piping is primarily due to 4 impingement of water droplets in'the high velocity steam. Since dry steam is not susceptible to erosion / corrosion, the primary routing guideline in dry steam lines -(e.g. , Main Steam) is to minimize low points and ptuvide moisture-removal at-the low points in the piping.
6.2.8.1.2 Wet Steam Pipe Routing Guidelines Wet steam riping (e . g . , Extraction Steam) is susceptible to erosion /co. Josion and should be routed to minimize moisture deep.let impingement. The following faldelines can be'used to achieve this:
A. Mirimize long runs of straight pipe ending in an elbow.
B. Route equipment inlet and outlet piping so'as to minimize impingement damage to the piping and equipment.
l C. Minimize flow rettrictions which will rurther accelerate the wet steam,- especially with close- proximity to downstream elbows.
D. Consider laterals rather than tees.
E. Place piping takeoffs on the top of - ti4e main line to minimize moisture carryover.
F. Minimize wet steam entering a' tee from the branch.
> 6.2.8.1.3 Flashing Liquid Pipe Routing Guidelines-Water lines wiH flow restrictions- (i.e., orifices, control valves) can experience 3shing to steam or. cavitation-, causing very high localized velot .es immediately downstream of the restriction _and severe piping.de adation. The primary method of damage prevention should be proper valve and pipe material specification (see Section 4.2.1.3.5.2). Degradation can 1 a be. reduced by placing several pipe diameters of straight pipe immediately downstream: of-the restriction, or by: increasing the downstream pipe diameter.
3 Note that normally closed valves with large-differential pressure are also susceptible to water flashing - degradation due to _ valve leakage.-- Pump recirculation ~ 1ines to the condenser are especially susceptible. The same methods described above should be used to reduce the pipe v211 thinning potential. Also, the isolation valve should be placed-as close as possible to the-condenser with no downstream directional changes.
-DRAFT 6-114 July 25,-1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIOUTION SYSTEMS DESIGN GUIDE 6.2.8.1.4 Liquid Pipe Routing Guidelines For liquid piping systems with fluid and material properties making it susceptible to erosion / corrosion, the piping should be routed to !
preclude high localized water velocities. This is mainly accomplished by minimizing close proximity fittings, especially downstream of tee branch connections.
6.2.8.2 Pico Wall Thinnina Inspection Provisions Piping systems susceptible to pipe wall thinning should be included in the plant pipe wall thinning inspection program. Accessibility for inspection (ultrascnic or internal) should be considered in sne routing. Items to consider include:
- Accescibility a Scaffolding erection Use of removable insulation 6.2 8.3 Manway Access for Internal Inspectfons For large bore piping requiring internal inspection, adequate
.hd.Way access Should be provided.
6.2.9 WATER / STEAM HAMMER PREVENTION Water and steam hammer has caused piping and piping support damage, and unplanned shutdowns at existing nuclear power plants. Proper design and pipe routing is vital to minimize damage during transients over the life of the plant. Water hammer and steam hammer can be minimized by the fo.owing pipe routing features.
6.2.9.1 Vertical Pipino Loco Minimization l For liquid lines which are close to saturation etnditions, or that encounter sizable pressure changes during transients, vertical piping loops should be avoided. These configurations provide an area for steam formation and collapse and the resulting water hammer.
6.2.9.2 Hioh Point Ventino Provisions venting provisions should be provided at piping high points to prevent air pockets during system startup or transients. ;
6.2.9.3 condensate Remo' val From Steam Pipino For steam piping, low points should be minimized and condensate
- removal provisions should be provided at those low points.
1 DRAFT 6-115 July 25, 1992
l SYSTEM 800* DES 8GN CERT 8FECAT20N DISTRIBUTION SYSTEMS DESZGN GUIDE
, 6.2.10 THERMAL STRATIFICATION MINIMIZATION Thermal stratification occurs when low (laminar) flow occurs with large thermal gradients in the horizontal piping. This condition can be minimized by reducing long horizontal runs of pipe with large temperature changes, or by reducing the potential temperature difference by system design changes.
6.2.11 FIELD ROUTED LINES Field routed lines are those 1.nes and associated components which have their layout determined by field personnel. Engineering personnel may stipulate connection points and general guidelines, but the bulk of the layout is done in the field. Because there is little design input into this type of line, it is much less expensive to install than lines with detailed design input. From a commercial standpoint, field routed lines are very desirable. On the otner hand, the reduced control by design personnel in locating these lines could later lead to interferences with other piping design routes.
6.2.11.1 Scope All of the following restrictions should be met for any piping to be considered for field routing:
Non-nuclear Safety (NNS) class Operates Jess than 150*F and 275 psig
- 2 inches or less NPS, or any size tubing Information to make this determination can be found on the flow diagrams. Note that portions of systems as well as entire systems, can be field routed.
The above described lines could be further restricted by system turnover dates. Systems required early during construction which are candidates for field routing should be designed to avoid interferences with designed piping.
6.2.11.2 Field Routino Constraints 6.2.11.2.1 Non-Safety Related Safety-related lines are necessary for safe shutdown of the reactor. Because of their safety function they must be routed so as to be operational under emergency conditions. Due to the importance of safety-related lines, they shall not be field routed.
DRAFT 6-116 July 25, 1992
- - - .- . . _ _ - - ._ .. . - _ _ - -= .. _-_
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE J
6.2.11.2.2 Cannot Interact With Safety Related Equipment Field routed lines cannot impair operation of safety-related equipment. For this reason, 200'F and 275 psig limits shall not be exceeded for field routed pipe in areas of the plant where safety-related equipment is located. This is to avoid assessing the interactions of a field routed high energy line with safety-related items (piping operating over 200*F and 275 psig is considered high energy). See Section 7.1.8.1 for more information.
For areas where there is no safety-related equipment, field routed lines may operate at rmperatures up to 300*F. This maximum temperature is goverr 3 in stress analysis requirements.
6.2.11.2.3 Does it Aequire Analysis Piping operating at temperatures greater than 300*F should not be field routed. The stress analysis required in piping with operating temperatures above 300*F requires detailed layout information that is not available for field routed lines.
6.2.11.2.4 Cannot Carry Radioactive Fluids Lines carrying radioactive fluids must be routed so as to avoj.
possible excessive radiation exposure. Possible hazards include routing radioactive lines through p3rsonnel areas as well as the formation of crud traps in liaas. In order to avoid these potential hazards, lines containing radioactive fluids shall not be field routed.
6.2.11.2.5 Small Diameter The absence of detailed drawings for field routed piping is a potential cause of interferences with designed piping. These interferences can be minimized by selectively field routing small ,
diameter lines. For purposes of this criteria, only two-inch and smaller lines can be field routed. This includes both piping and tubing.
6.2.11.2.6 Not Required Early In Construction l Even lines which meet all of the above fie.1d routing constraints could be required be designed in seme cases. These systems would be designed in order to meet early turnover dates. Designing these systems is justified duc to their potential for interactions with I
designed piping during design and erection.
Representative system lists are presented as a means to aid the engineer in his determination of the affect of system turnover schedules on lines which meet all other requirements for .. field routing constraints. These lists are not all inclusive nor are they definitive. They are meant to be used as a guide.
l DRAFT 6-117 July 25, 1992
..-e c-w.e -- = . -m
SYSTEN 80+* DESIGN CZRTIFICATION DISTRICUTION SYSTEMS DESIGN CUIDE The following is a list of the types of systems which have been field routed in the past. However, since they were required to be operational relatively early in the construction stages, they caused interferences with designed piping, and thus should not be field routed.
- Demineralized Water
- Drinking Water
- Instrument Air
- Station Air
- Dreathing Air
- Fire Protection Conversely, the following list is comprised of systems which may be field routed, and because of their relatively late turnover schedule will reault in few interferences.
- Feedwater Seal Water
- Conventional Condensate Sampling
- Condenser Tube Cleaning
- Chemical Addition
- Cooling Tower Chemistry
- Vacuum Priming In order to determine the effect of turnover schedules on the applicability of field routing, consult the two lists above. If the system in question is part of the latter list or if its turnover schedule is more in line with the latter list than the former, then field routing of the system cou1~d be practical.
6.2.11.3 rield Routine Desian Recuirements Design requirements should be specified on the field routing drawing. The following are design requirements that could be specified:
- Sloping for drains
- Special fittings
- Sleeve locations
- Avoidance of dead legs or pockets
- Limitations of routing near equipment
{ DRAFT 6-118 July 25, 1992 l
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE
- Hinimum dimensions
- Area access requirements 6.2.11.4 Interf ace Recmirements Field routed lines should not be connected directly to designed piping. Enough of'the field routed line should be designed to ensure that it will not impart significant loading to the designed line. For purposes of this criteria, three spans of " field routed" line should be designed at the interface. Typically, the first support into the field routed pipe at the design pipe interface is analyzed as designed piping. The three spans also provide a type of isolation between the designed piping and field routed piping.
If the three span requirement cannot be satisfied, the use of flex hose may be permitted. However, flex hose is a high maintenance item and a potential crud trap.
6.2.12 PUMP SUCTION PIPE ROUTING Pump suction piping should be routed for minimum friction loss to maintain adequate NPSH to the pump. Generally, low velocity (larger NPS) piping is used with a minimum number of elbows, tees, and other flow restrictions (see section 5.2.1. 6.1) .
6.2.13 FLOOD PROTECTION ,
Flood protection is required for all safety-related piping. In the Nuclear Annex, divisional separation is required to ensure a failure in one division does not affect redundant equipment in the other division. Divisional cross-connects should be minimized, and where cross-connects are required, they should be adequately sealed to prevent propagation of the flooding to the other division.
In the Reactor Building subsphere, quadrant separation should be maintained to ensure a moderate energy pipe break does not flood ECCS equipment in the other quadrant in that division.
6.3 HVAC DUCTWORK 6.3.1 GENERAL GUIDELINES 6.3.1.1 Plant Arranaement 6.3.1.1.1 Reservation of Ductwork Space Space for major HVAC equipment and ductwork should be reserved early in the design process, along with ductwork shafts and plenums. This practice, along with proper equipment placement and DRAFT 6-119 July 25, 1992
_ _ _ _ - . _ _ . 1
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE i orientation (see Section 4.3.2) , will minimize the amount of large ductwork required, and reduce rerouting required.
6.3.1.1.2 Minimize Duet Length . .
l 6.3.1.1.2.1 Equipment Placement Proper equipment placement and orientation improves system connectivity and thus reduces the amount of ductwork.
6.3.1.1.2.2 Pressure Differential Utilization wherever practical, system / area pressure differerntial should be utilized to preclude ductwork. An example would be the Reactor Building Subsphere Supply / Exhaust System. In this system, .the Engineered Safety Feature (ESF) Pump and Heat Exchanger Rooms are maintained at a negative pressure with respect to the adjacent maintenance access aisles. The supply air is distributed in the maintenance access aisles and enters the ESF rooms via door grilles, thus precluding any supply ductwork entering these rooms.
6.3.1.3 Zine Limitations in Containment The zinc in galvanizing is a potential source of hydrogen production in containment during a LOCA. Z,inc should be minimized to the maximum extent possible in containment. The total zine inventory in containment shall be limited to the amounts specified in CESSAR-DC, Table 6.2.5-4, unless justified.
6.3.2 HVAC DUCTWORK DESIGN The ductwork design and routing should incorporate the system requirements from Section 4.3.1, where applicable, plus the overall goal of ductwork minimization (see section 6.3.1.1.2) .
6.3.3 MAINTENANCE PROVISIONS Replacement and maintenance of HVAC equipment and in-line components should be considered in the design and routing as described below.
6.3.3.1 Standard components Standard components are easier to procure and allow ease of maintenance and interchanging. These components include fans, dampers, ductwork, filter units, recirculating cooling units, and supports (see section 6.1.3) .
DRAFT 6-120 July 25, 1992
I SYSTEM 80+" DESIGN CERTIFICATION DISTRIOUTION SYSTEMS DESIGN GUIDE 6.3.3.2 Access for Insoaction er service of Dameers Access should be provided for inspection and maintenance of dampers and other HVAC components. These provisions include duct access doors, damper location and damper orientation.
6.3.3.3 Adecuate space for Damper operators The type of damper operator should be considered as well as inspection and maintenance requirements for the damper operator.
6.3.3.4 Duct Location 6.3.3.4.1 Clearances Adequate clearances should be provided in the ductwork routing to allow for construction, testing, and maintenance. Clearances should take into account maximum tolerances. Provisions should also be made to remove ductwork sections for equipment removal and maintenance.
6.3.3.4.2 Leakage Tests Access should be provided for required leakage tests. Other necessary testing provisions should also be provided to perform the testing (i.e., bypass / isolation capability, instrutnentation) .
6.3.4 ALARA HVAC ductwork design and routing should support ALARA goals as described below.
6.3.4.1 Penetration Desion Penetration designs should provide compartment isolation. Factors to consider include differential pressure, penetration seal type, and contamination potential if not sealed (see Section 5.3.1.4).
6.3.4.2 Exhaust Systems Proximity should be provided to the appropriate exhaust plenum / shaft, and adequate space provided. for required exhaust filtering. Some exhaust systems have a bypass around the filter unit to allow normal filter bypass with automatic switching over to the filter units during an accident or high radiat!.on level detection.
6.3.4.3 Utilization of Necative Pressure Maintaining a slight negative pressure in a room or compartment minimizes the potential of contaminating adjacent rooms or DRAFT 6-121 July 25, 1992
_ ________---J
.- - _ _ _ . -. ~ __ - . - - . _ _ _ __ - . . ..- - . . . - -
l SYSTEM 800* DESIGN CERTIFICATION DISTRIOUTION SYSTEMS DESIGN GUIDE compartments. In addition, less ductwork is required. This feature should be used wherever practict.1.
6.3.5 SUPPORTS AND RESTRAINTS 6.3.5.1 Desion/ Analysis Criteria, Methods, and Philosophy All support and restraint (S/R) designs should include consideration of all applicable tolerances given in applicable drawings and specifications.
6.3.5.1.1 Function and Classification The purpose of HVAC supports and restraints is to provide adequate support for ductwork and equipment under normal and seismic conditions, where applicable. Accordingly, the S/R System should be designed to sustain forces generated by the ductwork and equipment masses subjected to a predicted seismic acceleration (see Section 7.2).
The HVAC S/R System is comprised of individual restraints acting in unison to sustain postulated forces. See Section 7.2 for analysis requirements for seismic HVAC supports. The individual restraints are classified and defined as follows.
6.3.5.1.1.1 Horizontal Duct Runs 6.3.5.1.1.1.1 vertical Support / Restraints A vertical support / restraint (S/R) is a restraint that transmits vertical forces to the building structure principally through tension or compression members. It is assumed to provide restraint in the vertical direction only.
DRAFT 6-122 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE Example:
FIGURE 6.3.5-1 Vertical Supoort / Rest ra i nt
+R & 4 ~. R j'.) ;{ j *,' , e,- { ; e, Y iy Building Structure Y .
I R =0 X \ X g .o Z
l/l\,I
,t.,y Note: The magnitude of positive Fy will not equal the magnitude of negative Fy since net seismic acceleration in the vertical direction is defined as 1 g plus or minus the seismic response acceleration obtained from the appropriate response curve.
6.3.5.1.1.1.2 Lateral Support / Restraints A lateral S/R is a re_;raint that transmits horizontal forces acting perpendicular to the duct's longitudinal axis to the building structure principally through tension or compression members. It is assumed, therefore, to provide restraint in the lateral direction only.
Example:
FIGURE 6.3.5-2 Lateral Suoport/ Restraint Building Structure Y
! ,I r *R .
x
- r ; x *',, R =0 x
1/iN -
x Y
R -o l k Y
DRAFT 6-123 July 25, 1992
SYSTEN 80+5 DESIGN CERTIFICATION .
DISTRIBUTION SYSTEMS DESIGN GUIDE ,
6.3.5.1.1.1.3 Vertical-Lateral Support / Restraints f
. A vertical-lateral S/R is a restraint to thatthe transmitsbuilding structure both vertical i and horizontal (lateral) . forces l principally through tension or compression members. It is assumed to provide restraint in both the vertical and lateral directions only.
Example:
FIGURE 6.3.5-3 Vertical-Lateral Support / Restraint 1 Rh aR 2y 1R3y Building Structure
- - l.' Note: i R,y d t R,y d t Rey 1 R;x 1R 2x -
"3x t R , # 2 R,, d i R,,
3 Y
x N/
f\
x o.g U
6.3.5.1.1.1.4 Axial Support / Restraints An axial S/R is a restraint that transmits horizontal (axial) forces acting along the longitudinal duct axis to the building structure principally through tension or compression members. It is usually also a vertical restraint. It is assumed, therefore, to provide restrair.t in both the axial and vertical directions only.
FIGURE 6.3.5-4' Axial Suocort/ Restraint 1 "ly 1 "2y p Building Structure p
, 'e n:
"1 R 1z 1 "2z 1
~
Z h [- .Q ,
~
8
- I . Note: t R,y A t Ray l ,1Fy iRig# trig l
DRAFT 6-124 July 25, 1992
^
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN CUIDE 6.3 5.1.1.1.5 Three-way Support / Restraints A three-way S/R is a restraint that transmits forces in all three orthogonal directions to the building structure principally through tension or compression members.
Example:
FIGURE 6.3.5-5 Three-way Suecort/Pestraint
-Apky a "2y A h3y 4 ty 1 2y
+1 < L i .. Building y d u' e 's *
/ !.'. . . o _ _ i , '. 9 Structure ,e p _ q 6 $,'[
1 R 2z g R), *R yx
,, 1R 3 : Rg y
z -
- z x ax : r; e r, t ' og F y a
o+p.
y U V-See A A Mote; tR,d iR,d R.x i
iR y i d
R,y d R i y
d R.
y iR g # t R,Z-i 6.3.5.1.1.2 Vertical Duct Runs (Risers) 6.3.5.1.1.2.1 Three-way Support / Restraints A three-way S/R is a S/R which, under normal operating conditions, transmits only vertical forces to the building structure. During seismic conditions, the S/R could transmit forces in both the horizontal and the vertical- direction to the - building structure principally through tension or compression members (see Figure
- 6. 3. 5-6) .
DRAF*L 6-125 July 25, 1992 l
-1
SYSTEM 80+5 DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN CUIDE 6.3.5.1.1.2.2 Lateral-Vertical Support / Restraints A lateral-vertical S/R is a S/R which, under normal operating conditions, is assumed to transmit no forces to the building structure. During seismic conditions, this S/R could transmit forces in either of the two horizontal directions, the vertical direction, or any combination of these to tho building structure The vertical principally through tension or compression members.
forces during seismic conditions are assumed to be transmitted to the S/R via 'stop' angles. (See Figure 6.3.5-6) .
Example:
FIGURE 6.3.5-6 Lateral-Vertical Support / Restraint b,
$I +
A \f e ,$,,
7* ,
'Q- %ree-Way 5/R (attached to duct)
'Stop* angles attached to duct (Typ.)
4 \ #
f w i 3
( Lateral - Vertical S/R
/ (not attached to duct)
W N, f Bullding
_; .i S [tructure
\s_/
3 i 1/2" (Typ.)
hI '
l 6-126 July 25, 1992 DRAFT
SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 6.4 ELECTRICAL CABLE TPAYS/CONDUTT 6.4.1 CABLE TRAYS 6.4.1.1 Tvoeg 6.4.1.1.1 Safety-Related Safety-related cable trays are those containing safety-related cabling which supply power to Class 1E loads.
6.4.1.1.2 Permanent Non-Safety Related Permanent non-safety related cable trays are those containing cabling which supply power to non-safety loads that, due to their specific functions, are generally required to remain operational at all times or when the unit is shut down.
6.4.1.1.3 Non-Safety Related Non-safety related cable trays are those containing cabling feeding non-safety loads required exclusively for unit operation.
6.4.1.2 Locations 6.4.1.2.1 Space Allocation Sufficient space should be allocated early in the design process for cable trays. Cable trays typically are arranged in the overhead and along the walls and generally require a great deal of l space for routing, particularly in the areas under the control room.
The cable tray system should be designed with adequate space
, between the bottom of the tray and the top of equipment, especially when drip loops are required.
Cable tray systems should be designed such that trays are no closer than 6 inches to a wall, ceiling or column.
Cable trays should be routed away from hazard areas.
l 6.4.1.2.2 Physical Identification All cable trays, conduits, and wireways containing Class 1E cables should be color coded for ease of identification and to assure that separation is maintained. These raceways should be marked at each end, at all entrances and exits to rooms, and at intervals not to exceed 15 feet. Raceways should be marked prior to the !
installation of their cables.
DRAFT 6-127 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIEUTION SYSTEMS DESIGN GUIDE 6.4.1.2.3 Accessibility for Cable Pulls The overall design of electrical power distribution systems should take into account personnel and equipment accessibility for making required cable pulls. Since cable trays are typically located in the overhead, access for cable pulls is limited. The designer should consider access to creas which would typically be used by personnel to make cable pulls.
6.4.1.2.4 Accessibility for Maintenance Cable trays should be exposed and accessible. Sufficient space should be provided and maintained around cable trays to permit adequate access for installing and maintaining cables.
6.4.1.3 Seoaration 6.4.1.3.1 Divisional / Quadrant Separation Divisional separation shall be maintained to the maximum extent possible. Safety-related cable crossing divisional walls shall be designed to prevent fire propagation to redundant equipment in the other division. This can be achieved by embedded conduit, physical separation, or adequate fire barriers.
Fire barriers should be provided for the ECCS equipment in the Reactor Building subsphere to separate the safety trains in that division.
6.4.1.3.2 Fire Protection All openings for cable and cable tray runs in fire rated walls and floors should be protected consistent with the rating of the wall or floor.
I Cable tray systems should be designed to use natural barriers and l to minimize distances as much as possible.
6.4.1.3.3 Cable Segregation by Voltage Levels To reduce fire hazard and prevent high energy power cables from af fecting instrumentation and control circuits, cable trays should be arranged physically, from top to bottom,' in accordance with the function and voltage class of the cables, as follows:
- 15 KV power cables
- 8 or 5 KV power cables
- High level signal and control cables (120 VAC, 125 VDC)
- Cables for low level analog and digital signal DRAFT 6-128 July 25, 1992
_ . _ . _ . ~ . _ . _ . _ _ _ . __ _ _ _ _ __ _ _ . _. __ _ . . _ . _ . _ . _ . _ _ _ _ . - _ _ __. _ _.
I SYSTEM 80+" DESIGN CERTIFICATION- )
DISTRIBUTION SYSTEMS DESIGN GUIDE A cable tray designated for a single class of cables should contain only cables of that same class. ,
To prevent spurious signals from being induced into low voltage instrumentation circuits from external sources, cable trays containing low voltage instrumentation cables should- provide j protection against spurious signal sources.
6.4.1.4 Material Renuirements 6.4.1.4.1 Aluminum Limitations in Containment i Aluminum cable trays should not be used in Containment due to the hydrogen generation potential during a LOCA. Aluminum limits in Con.31nment are specified in CESSAR-DC, Table 6.2.5-4. ,
6.4.1.4.2 Zine Limitations in Containment The zine in galvanizing' is a potential source of hydrogen generation during a LOCA. For this reason, zinc should be .
minimized to the maximum extent possible in Containment. Zinc limits in Containment are specified in CESSAR-DC, Table 6.2.5-4, 6.4.1.4.3 Cable Tray Materials For consistency with current practice to minimize fire hazard, only metal should be used for cable trays.
6.4.1.5 Cable Trav Fill Criteria The cable tray system-should be designed with sufficient trays to prevent overfilling with cables.
6.4.1.5.1 Power Cables .
t The cable tray fill criterion for those trays containing power cables allows only one single layer of power cables to be routed in any tray. In general, separation of one-quarter of the diameter of the larger cable should be maintained between adjacent power-cables within a cable tray.
6.4.1.5.2 Instrumentatien and Control Cables The cable tray fill criterion for those trays containing instrumentation and control cables is that the cross-sectional area of chese cables should not exceed the usable cross-sectional area of the tray.
DRAFT 6-129 -July 25, 1992 I
. . g- +r w -r em ,w .e , e -,w e w- '
1
. SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 6.4.2 CO!1DUIT 6.4.2.1 conduit acutina 6.4.2.1.1 Bend Radius Guidelines The cabling systems should be designed so as to observe minimum bend.ag radil for cables and ensure that cable pulling loads do not exceed the allowable limits of cable tensile strength guaranteed by the cable vendor. This requirement will prevent damage to cables due to improper handling, and installation methods and practices. ,
6.4.2.1.2 Water Exclusion' Guidelines Where it is possible for water or liquids to enter conduits, they should be sloped downward away from equipment and drained at low points.
Where conduit enters equipment enclosures from the top, the installation should be designed to prevent water from entering the equipment. If the installation is such that condensation could occur in the conduit, a drain fitting should be installed at the equipment.
Conduit should be sealed where it enters buildings to prevent water drainage into the building.
6.4.2.1.3 Pull Boxes Adequate pull boxes should be provided in conduit runs in order to install cable without damage. The maximum distance between pull points for a straight run of exposed conduit is 200 feet. For each 90* bend in the conduit run, 50 feet should be deducted from the length of the run between pull points. Where possible, it is good design practice to locate the pull box where the conduit makes a 90' bend. The distance between pull boxes in a vertical conduit run should be no greater than the required support spacing for the cable installed in the conduit.
6.4.2.2 Separation 6.4.2.2.1 Divisional / Quadrant Separation For divisional and quadrant separation criteria for electrical cable, see Section 6.4.1.3.1.
6.4.2.2.2 Fire Protection For electrical cable fire protection guidelines, see Section 6.4.1.3.2.
DRAFT 6-130 . July 25, 1992
{
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE 6.4.2.2.3 Embedded Conduit The spacing between embedded conduits should be three times the diameter of the conduit unless a closer spacing is justified.
6.4.2.3 Material Recuirements Rigid metal conduit or metal raceways should 9 used for cable conduit in air. Flexible metallic tubing shot' d be used only in short lengths for equipment connections. Non-metallic conduit should only be allowed when used with concrete encasement or for direct burial runs.
Aluminum conduit should not be used in Containment due to the hydrogen production potential during a LOCA. Aluminum limits in Containment are specified in CESEAR-DC, Table 6.2.5-4.
6.5 INETRUMENT LINES 6.5.1 DEFINITIONS 6.5.1.1 In st rument at ion Instruments, instrument lines, and associated hardware (i.e.,
valves, fittings) used in the installation of loops whose function is to monitor, control, or sample parameters of a process system.
6.5.1.2 Instrument Lines 6.5.1.2.1 Impulse Lines ,
Impulse lines consist of piping, tubing, fittings, and valves are used to connect instruments to process piping, process components, ductwork, or to an enclosed area (e.g., Containment). Sealed reference legs are considered to be part of the instrument.
6.5.1.2.2 Control Lines 6.5.1.2.2.1 Supply Air Lines Supply air lines consist of piping, tubing, fittings, and valves used to connect plant instrument air to pneumatic instrumentation.
6.5.1.2.2.2 Transmitted Air Lines Transmitted air lines consist of piping, tubing, fittings, and valves used to connect air-operated control apparatus and/or pneumatic transmitters to other pneumatic instruments.
DRAFT 6-131 July 25, 1992
4
~
SYSTEM 80+* DESIGN CERTIFICATION -
DISTRICUTION SYSTEMS DESIGN CUIDE 6.5.1.2.3 Sample Lines i Sample lines consist of piping, tubing, fittings, and valves used for the collection of samples of steam, water, oil, gases, or other process fluids.
6.5.1.2.4 Blowdown Lines Blowdown lines consist of piping, tubing, fittings, and -vaJves i connected to impulse lines in. order to provide a means to :
periodically clean the impulse line with process media.
6.5.1.2.5 Filled Capillary Lines ,
Filled capillary tubes consist.of piping, tubing, fittings, and valves used to connect instruments - to a process sensor _ (i..., e bellows sensor, diaphragm seal) . These lines are filled 'with a fluid which transmits a signal _from the sensor to the instrument, and serves. to isolate the instrument. from the process- fluid.
6.5.1.3 Root Valvee Root valves are isolation valves at the process tap.-
6.5.1.4 Shance in Direction All other bends greater than 10 degrees should be considered a change in direction for typical tube spans.
6.5.1.5 Track Suocorts Track supports are designed to support tubetrack. ,
6.5.1.6 Tube Suncorts Tube supports are designed to support tubing- contained in tubetrack or support tubing lines routed individually.
6.5.2 GENERAL Instrument lines are to be field routed unless otherwise specified on design drawings. The route selected should be-the most. direct-route-possible-with the following restrictions:
A. The routing of liquid filled lines over electrical control-panels, cabinets, or enclosures should be avoided.
B. Walkways and access- areas should be kept adequately cleared. Instrument lines should be. routed sufficiently dbove the finished floor levels when required to? cross access areas.
DRAFT 6-132 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION
- DISTRIBUTION SYSTEMS DESIGN GUIDE C. Instrument lines should be routed:
- 1. At least six inches from the outside insulation of any steam line.
- 2. At least two inches from all other piping and equipment.
- 3. At least four inches, (in the pressurizer cavity) from all other piping and equipment.
D. The requirements of Section 6.5.8 should be met'at all times, i
E. When instrumentation is removed or modified, the
, disconnected tubing is to be capped on both ends. There
, should be no open ended tubing unless specified on a design document.
I j 6.S.3 IMPULSE LINES 6.5.3.1 Slope Recuirements All gas filled impulse lines are to be sloped upward from the !
. process tap. All liquid filled impulse lines are to be sloped downward from the process tap. For steam filled applications, impulse lines may be sloped upward or downward from the process tap as dictated by the physical arrangement of each application. The normal recommended slope is one inch per foot. Minimum slope should be one-quarter of an inch per foot.
6.5.3.2 Impulse Line Size The line size from the last root valve to the instrument isolation or manifold valve should be % inch tubing unless otherwise specified on the instrument detail drawing.
Blowdown Lines 6.5,3.3 i Where blowdown lines are required, the impulse line should be routed to a point near the instrument then drop down to the blowdown line. The impulse line should be oriented in- such a manner as to trap sediment in the blowdown'line.
6.5.3.4 Process Tao connections Process tap connection locations should be specified on design drawings.
DRAFT 6-133 July 25, 1992 l
1 I
SYSTEN 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN CUIDE 6.5.3.5 Instrument with Two connections A. The top connection should be used on gas filled impulse lines. The bottom connection should be used for drains.
B. The bottom connection should be used on liquid filled impulse lines. The top connection should be used for vents.
6.5.4 CONTROL LINES 6.5.4.1 Main Air Headers and Branch Lines A. Main air header routing should be designed rather than field routed. .
B. Branch air lines may be field routed. All branch lines should connect to the top of the main headers and isolation valves should be provided as close to the main header as possible.
C. Branch lines should be routed to avoid low points and moisture traps. In places where low points and moisture traps cannot be avoided, drains should be provided for water collection. Drain valves should be 4 of the henaer size or smaller to prevent excessive pressure drop during blowdown.
6.5.5 SAMPLE / PROCESS LINES Sample / process lines can be routed and supported as impulse lines if the process fluid temperature is less than or equal to 150*F.
Sample / process lines with process fluid temperatures above 150'F should be designed piping.
6.5.6 SEPARATION CRITERIA Functionally redundant instrument lines for safety-related instruments should meet the physical separation criteria of eighteen inches minimum separation (edge-to-edge) . When functionally redundant process connections have less than 18 inches separation or a common tap is used for more than one functionally redundant measurement, the minimum separation. (18") should be obtained in the shortest practical distance and maintained for the remaining length of the instrument lines. Functionally redunt',nt instruments are those which measure the same parameter on the same piece of equipment and provide-the same safety function.
6.5.7 EXPANSION COILS Expansion coils should be used in non-safety related applications when connecting to a process system that has a design temperature DRAFT 6-134 July 25, 1992 l
SYSTEN 80+* DESIGN CERTIFICATION i DISTRIOUTION SYSTEMS DESIGN GUIDE greater than or equal to 300*F. The coil should be seven (~
inches or greater-in diameter with a minimum of four (4) coils. '
should be made with the appropriate size tubing and installed ,
close as possible to the root valve.
6.5.8 SPECIAL ROUTING AND SUPPORTING REQUIREMENTS All control and impulse lines should be routed and supported by either the requirements of Section 6.5.3.1 or 6.5.3.2.
6.5.8.1 Free Tube Soans The routing and analysis requirements for tubing that is supported by free tube spans (rather than tubetrack) are described in Section 7.1.11.2 and Table 7.1.11-1. .
6.5.8.2 Track Suecorted Tubes The routing and ar csis requirements for impulse and control lines routed in-tubetra.4 are. described in Section 7.1.11.3. Sample lines should not-Le installed in tube tracks unless the process fluid temperature is less than or equal to 150*F.
Tubetrack should not be modified by cutting or bending without approval from the designer.
6.5.8.3 Soccort and Mountino Reauirements Support and mounting requirements for tubing are described in Section 7.1.11.4.
i TABLE 6.5-1 Minimum Tube Bendino Radii Tube OD Minimum Bending Radius 1/4" 1-1/4" 3/8" 1-7/8" 1/2" 2-1/2" 5/8" 1/8" l 3/4" 3-3/4" 1" 5"-
DRAFT 6-135 July 25, 1992
. . . - . - . - - - - . . . ~ . - . . . ~ . _ . . - - . - .--
) .
j SYSTEN 80+" DESIGN CERTIFICATION I DISTRIEUTION SYSTEMS DESIGN CUIDE
- 6.5.9 TUBE BENDS The minimum bending radius (50 bends) should not be less than shown .
i l in Table 6.5-1. Tube fittings should- be used whenever smaller bending radii are requized. ,
6.6 REFERENCES
-4 6.6.1 ASME B31.1-1989 Edition, Power Piping. ;
^
6.6.2 ASME Boiler and Pressure Vessel Code,Section XI,1989 Edition.
NCIG-14, " Procedure for Seismic Evaluation and Design of 6.6.3 '
Small' Bore Piping", EPRI NP-6628, April 1990.
6.6.4 CE9.3AR-DC Design Certification, System 80+ Standard Design, Amendment I.
1 i
i i
-i t
i
. DRAFT 6-136 July-25, 1992 :
. . . . . - . . , - . . . . _ - - . . . .a._...--..,-..,......_..-..-., . . _ , ,._..-_.c..._,,; . , _ , , ,
SYSTEM 80+5 DESIGN CERTIFICATION l DISTRICUTION SYSTEMS DESIGN GUIDE 7.0 DTSTRIBUTTON SYSTEMS ANALYSTS REOUTREMENTS :
l ?
7.1 PIPTNG 7.1.1 GENERAL 4
4 Seismic Category I piping, as defined in CESSAR-DC, Section 3.2.1, shall meet the analysis requirements of the ASME Boiler and t
! Pressure Vessel (B&PV) Code,Section III, Subarticles NB-3650, NC-l 3650, and ND-3650.
Seismic Category II piping, as defined in CESSAR-DC, Section 3.2.1, should be analyzed to the same requirements as Category I piping.
Category II requirements are conservatively satisfied by ' analyzing the piping to the same criteria as Category I.
Non-Category I and II piping shall be designed to meet the- '
requirements of ASME B31.1, Power Piping.
The analysis requirements described in Section 7.1 apply only to Seismic Category I and II piping. Note that in some cases, other analysis methods may be utilized, such as new analysis techniques and computer codes, where justified.
7.1.2 DESIGN CONSIDERATIONS ,
7.1.2.1 Pressure The pipe wall thickness shall be sized to accommodate the specified internal pressures and meet the requirements of the ASME B&PV Code,Section III, Subarticle 3640. Stresses due to the-system design pressures and maximum peak pressures should be included in the acceptance criteria.
7.1.2.2 Gravity The weight of the pipe, in-line components, contents-of-the-pipe and insulation shall be included. The weight ' of water during hydrostatic testing shc11 be considered for steam or air-filled ,
lines.
7.1.2.3 Thermal The effect of thermal expansion of the system due .to the des'ign temperature shall be included. Possible operating modes of the system that will result in more seveze thermal expansion stresses than the entire system at--design temperature should be considered =.
The maximum. operating temperature may be used in lieu of design temperature where available. i The effects of anchor movement .due to- thermal expansion- of-equipment or other piping should be considered.
DRAFT 7-1 July 25, 1992
~
SYSTEN 80+* DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE :
7.1.2.4 Seismic The effects of earthquake loading shall be considered. The inertia loads and movements, including. earthquake anchor movements, and the effects of fatigue shall be included in the-analysis.
7.1.2.4.1 Seismic Anchor Movements Seismic anchor motion shall be included for-piping supported by more than one structure by applying / 1) the - building seismic movements, and/or 2) equipment seismic movements, as support movements on the pipe.
The support movements'should be assumed in the-most conservative combination for adjacent structures to give the :maxhnum stress in the pipe, unless the relative time phasing of the tactions of 'the supporting structures or equipment is' determined-by simultaneous i time history analyses. The effects of seismic anchor motion on the piping should be included for the operating basis earthquake _(OBE) only. Seismic anchor motion produces secondary stresses and-should not be evaluated with the safe shutdown _ earthquake (SSE);except for 5 supports.
7.1.2.5 Wind / Tornado ;
Exposed piping shall be designed to withstand wind and tornado loads. Simultaneous wind and tornado loads are not considered. -
7.1.2.6 Fluid Transient Loadinos ,
B 7.1.2.6.1 Relief / Safety Valve. Thrust
+
Valve thrust loads should be considered for both open and closed ;
valve discharge cases. All thrust loads should first be considered !
for their significance. If _ considered a- significant : transient, i steady state thrust loads _should be applied to4the piping system.
If determined insignificant, then thrust loads' need not.be applied, ;
i 7.1.2.6.2 Water and Steam Hammer 5 i
Water and steam hammer are dynsmic loadings on. piping that. are' caused ~by a sudden change in momentum of the flow medium due to a 3 rapid system transient. [
t Although hammer effects- can potentially occur on anyfline where [
valve closing _ time'is-less than 3 seconds, the1 effects on small !
lines are generally negligible and only_ large : lines with high-pressures, large flow rates, and very rapid closing valves need to e be-evaluated. [
t i
DRAFT 7-2 July 25, 1992:
, _._,_.____m._. _ _ _ _ . _ _ _ . 4. m a-
SYSTEM 80+* DESIGN CERTI7ICATION DISTRIBUTION SYSTEMS DES 2GN GUIDE 7.1.2.6.3 Other Loadings Other fluid transient loadings such as pump start, check valve slam, cnd filling empty lines should also be considered.
7.1.2.7 Pipe Break Loads Pipe break loadings can consist of pipe whip, jet impingement, dif ferential pressuro, support movements, or temperature increases resulting from the rupture of nearby pipes other than the line
- under consideration.
4 7.1.2.8 Thermal Stratification 1 Piping subjected to stratified flow conditions should be evaluated for the effects of thermal stratification.
7.1.2.9 Missile Loads Piping subjected to the loads described in CESSAR-DC, Section 3.5.1 shall be evaluated for the effects of missiles.
7.1.3 DESIGN LOAD COMBINATIONS Loading combinations, in accordance with CESSAR-DC, Section 3.9.3.1, applicable to ASME Class 1 piping shall be as detailed in Tables 7.1.3-1 and 7.1.3-2.
Load combinations applicable to ASME Class 2 and 3 piping shall be detailed in Table 7.1.3-3.
7.1.4 ANALYSIS Static and dynamic analyses, as defined in this section, should be based on linear elastic analysis methods.
7.1.4.1 Gravity Analysis The gravity analysis shall include the weight of the pipe or piping component, the weight of the enclosed fluid, the weight of all other sustained mechanical _ loads, and the weight of any attached insulation. Also, if the system contents vary during operation, the analysis should consider all modes of operation. Weight due to attached support / restraints should be included if determined to be significant.
DRAFT 7-3 July 25, 1992
SYSTEM 80+5 DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE TABLE 7.1.3-1 Desian Conditions and Lead Combinations for ASME Class 1 Piping CONDITION LOADS COMMENTE
- 1. Design Condition Design Pressure Weight Other Sustained Mechanical Loads OBE Inertia (1/2 range) .
- 2. Normal and Upset Range of Operating Combination used Conditions (1) Pressure for Eq. 10, NB-(Reference Table Thermal Expansion and 3653.1 7.1.3-2, Notes 1 Transients and 4) Anchor Hovements (TAM, OBE, SAM, DFL)
OBE Inertia Other Mechanical Loads Dynamic Fluid Loads (2)
Thermal Expansion Combination used Thermal Anchor Movements for Eq. 12, NB-Thermal Transients 3653.6 (if required)
Weight Combination used Other Sustained Mechanical for Eq. 13, NB-Loads 3653.6 (if OBE Inertia (1/2 range) required)
Range of Operating Pressures Dynamic Fluid Loads.(2)
- 3. Emergency Conditions Maximum Pressure Weight SSE Inertia (1/2 range).
Other Sustained Mechanical Loads Dynamic Fluid Loads (2) i
- 4. Faulted Conditions Maximum Pressure t (3) Weight l SSE Inertia (1/2 range) i Other Sustained Mechanical Loads Pipe Rupture Loads l Dynamic Fluid Loads (2) l l
l DRAFT 7-4 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE TABLE 7.1.3-1 (Cont'd)
Desian Conditions and Load Combinat ions _ for ASME Class 1 Pipino C0tIDITION LOADS COMMEt1TS
- 5. Testing Conditions Pressure, TempJrature, and Hydrostatic Test as defined in established system tests 1
NOTESt
- 1. The method for analyzing Upset Conditions is the same as for i Normal per NB-3654.
- 2. Dynamic Fluid Loads (DFL) are occasional loads such as safety / relief valve thrust, steam hammer, water hammer or other loads associated with Plant Upset or Faulted Condition as applicable. The worst combination of pressure, weight, sustained, seismic, and DFL loads should be checked.
- 3. Dynamic loads are combined by the square root of the sum of the squares (SRSS).
DRAFT 7-5 July 25, 1992
CYSTEM 80+" DESIGN. CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE TABI7 7.1.3-2 Code Compliance Criteria for ASME Class 1 Picino CHECK FOR CODE COND? TION STEP COMPLIANCE PER I8)
- 1. Design 1A Primary Stress Eq. 9/NB-3652 Conditions Intensity Limit
- 2. Normal and 2A.1 Primary Plus Eq. 10/NB-2653.1 Upset Secondary Stress (1)
Conditions Intensity Range (5) (6) 2A.2 If Eq 10 is met, Eq. 11/NB-3653.2 calculate Peak (2)
- cress Intensity a-
~
(S,). If
. . . , skip to Step 2B.1 2A.3 Calculate Sais. - 1/2 S Alternating Stress NB-3653.3 (3)
Intensity (Sats.)
2A.4 Evaluate Cumulative NB-3653.4, 3653.5 Usage. If NB-3222. 4 (e) (5) acceptable, proceed to check Faulted Conditions 2B.1 If Eq.10 is not met, Eq. 12/
perform Simplified NB-3 6 53. 6 (a )
Elastic-Plastic DisUcntinuity Analyn is - (4 )
2B.2 Check Primary Plus Eq. 13/
Secondary Stress NB-3653.6(b)
Intensity Range 2D.3 Calculate Sag, Eq. 14/
NB-3653. 6 (c) (3) 2B.4 Evaluate Cumulative NB-3653.4, 3653.5 Usage. If NB-32 22. 4 (e ) (5) acceptable, proceed to check Faulted Conditions DRAFT 7-6 July 25, 1992 P
h
SYSTEM 80+" DESIGN CERTIFICATION-DISTRIEUTION SYSTEMS DESIGN GUIDE TABLE 7.1.3-2 (cont'd)
Code Comoliance Criteria for ASME Class 1 Picino CHECK FOR CODE CONDITION STEP COMPLIANCE PER (8) 3.' Emergency Conditions I.ATER
- 4. Faulted 4A Determine maximum App . F - ( 8 )
Conditions faulted pressure 4B Check Primary App. F (8)
Intensity Limit
- 5. Testing SA Check General NB-3226 (a)
Conditions (7). Primary Membrane
-Stress Intensity SB Check-Primary NB-3226 (b)
Membrane Plus Bending-Stress Intensity SC Check External NB-3226 (c)
Pressure C
SDL Incorporate Test NB- 3226 (d) i Condition into NB-3226 (e)
Fatigue Evaluation NOTES:
- 1. If Eq. 10 is not met,-the component may.still-be satisfactory provided Eq.'12/ NB-3653.6 is met or the-requirements of NB-3200-are satisfied.
- 2. The purpose of this equation is to_ calculate the value of S, using the same load-sets used to evaluate Eq. 10.
- 3. Sm, is used in conjunction with the - Design Fatigue Curves to-determine the allowable number-of cycles p3e NB-3653,4.
4.- Qualifying' Normal / Upset Conditions =using the simplified Elastic-
~
Plastic Discontinuity Analysis per Eq.-12 is necessary only for ,
points that do not satisfy Eq. 10.
DBAFT 7-7 July 25, 1932
)
. . . . .. - . . -. . = - _ - - . .. , . - . , . . .
s SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN-GUIDE TABLE'7.1.3-2 (Cont ' d) t Code Comoliance Critoria for ASME Class 1 Picino
- 5. The methcd for analyzing Upset conditions.'is the same as for-Normal-per NB-3654.
- 6. These limits'must be satisfied for all possible ranges. .
- 7. Alternatively, Test Conditions may be included'as part of Normal '
and Upset Conditions to be checked.
- 8. Articles referenced is taken from-the ASME Boiler and Pressure Vessel Code,Section III.
d i
DRAFT 7-8. July 25, 1992.
.t SYSTEN 80+" DESIGN CERTIFICATION'- ,
DISTRIBUTION SYSTEMS DESIGN GUIDE
- r o TABLE 7.l.3-3 1
i iDesion Conditions, Load Combinations,'and Code Comnliance
! Criteria for ASME Class 2 and 3 Piping i
j CHECK FOR CODE . . -!
CONDITION LOADS COMPLIANCE PER (5) i i, 1. Normal
- a.-Sustained Pressure Eq. 8, NC/ND-3652'
-Loads (4) Weight (6) ;
- b. Thermal ~ Thermal Expansion Eq.'10, NC/ND-3653.2 Expansion . Thermal Anchor -(3)
Movements l c. Sustained Pressure 'Eq. 11, NC/ND-3653.2 j Loads +- -Weight (6) .
(3) .
- Thermal Thermal Expansion
- Expansion Thermal Anchor j Movements-
- 2. Upset Prescure' -Eq. 9, NC/ND-3653 a
- Weight (6)
DFL (2)
OBE (Inertia)
OBE (Anchor l Movements) (1) j or Wind (8)
L
~
- 3. Emergency ' Pressure Eq.-9, NC/ND-3652.1- .
- l. -Weight (6)
! DFL (2) ..
l SSE (Inertia)
- or Tornado - (8)
- 4. Faulted Pressure .Eq. 9,.NC/ND-3653.1 Weight (6)
- Pipe Rupture
- , SSE (Inertia) .
] DFL (2)-
l i
- 5. Fu.tetional Pressure ~ See Note 7 i Capability Weight- (6) . ,
1 SSE (Inertia)
, DFL (2)'
Pipe'Prpture -
l
}
1 i
DRAFT- 7-9 July 25,_1992!
, . _ . - _. . n, _ ..;._.-_.,_,,, . . , . , . . . , _ , , . . , ., ,m... ._.,,..-.;.._.._,,...,..-
. - . - -. - - . . .- . - . - . . . . - - - - -- - - - -~ - - .-- . -
- SYSTEM'80+" DESIGN CERTIFICATION ,
-DISTRIBUTION SYSTEMS DESIGN GUIDE.
- TABLE 7.1.3 (Cont' d) i Desian Conditions, Load Combinations, and Code Comolian'e e Criteria for ASME Class 2 and 3 Pipinc 1
1 i
NOTES:
(
- 1. Stresses due to seismic displacements.such as anchor-movements may alternatively be considered as secondary-stresses and
- combined with thermal expansion in Eq. 10 or 11 and omitted from j Eq. 9,
- 2. Dynamic Fluid Loads (DFL) are occasional._ loads such as
- safety /relicf valve thrust, steam hammer, water hammer or' loads associated with Plant Upset'or Faulted Condition as applicable, j 3. Stresses must meet the requirements
- of either Eq. . 10 or Eq. 11 (i.e., both conditions need not lus satisfied) .
I 4. If, during. operation, the system normally carries a medium.other than water (air, gas, steam), sustained loads should be checked for weight loads during hydrostatic cesting as well as normal ,
operation weight loads.
! 5. Articles referenced' from the AsME Boiler and Pressure Vessel. i Code,Section III.
i S. Weight' loads include all sustained Mechanical Loads.
4 I 7. Functional capability is not a standard loading condition as:
4 defined by the ASME Code. However, functional capability must be-i maintained for ASME Class 2 and 3 stainless. steel elbows. See j Appendix 7B for the acceptance criteria.
- 8. Wind and tornado loads are not combined with. earthquake ?.oading, i
- 9. Dynamic loads are combined by the square root of the sum of-the 4 squares (SRSS).
1 i
i i-i
^
J 1
i 1- DRAFT 7-10 July 25, 1992 e
4
,w--r w---.-,- -5y .e--.-r g'-e- r. r--qy-h-, , - - , - . -
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 7.1.4.2 Thermal Analrsis A thermal analysis of piping systems shall take into account forces and moments resulting from expansion and _ contraction. For all analyses, the ambient temperature should be taken to be 70'F.
Flexibility analyses should be based on the material property values at the temperature under consideration. Therefore, the analyses should be based on the value of Young's modulus at temperature, Enot. ASME Coda requires that stresses should be based on E,o ta . This may be accomplished by multiplying the analysis results by Ecoig/E ,s 3 .
All possible operating modes should be evaluated to determine the highest range of thermal expansion streMs. The effects of anchor movement due to thermal expansion of equipment or otnu piping should also be considered.
7.1.4.2.1 Specific Thermal Requirements for Class 1 Piping The thermal analysis shall include a check of the stress intensity range and shall evaluate f atigue (as expressed by cumulative usage) for all normal and upset operating temperature distributions, the transient events experienced in going from one operating mode to another, thermal anchor movements associated with the operating conditions and transients, and all test conditions.
7.1.4.2.2 Thermal Stratification .
Piping systems with low flow rates and potentially subjected to stratified flow may require evaluation for additional thermal stresses due to thermal stratification. Stratified flow exists when a hotter fluid flows over a colder region of fluid. This condition induces a vertical thermal gradient resulting in increased overall bending stresses and localized thermal gradient stresses.
A linear thermal gradient will cause a convex upward curvature, K, in an unconstrained pipe equal to:
K= (Eqn . 7.1-1)
D Where: AT = T ,, - Tutto. (with Tro, > T utto.)
D = Pipe outside diameter n = Thermal expansion coefficient The resulting bending stresses should be calculated by allowing the pipe to thermally expand unconstrained and then applying a set of equal and opposite displacements at the rigid suppert points.
DRAFT 7-11 July 25, 1992
(
1
SYSTEM 80+* DESIGN CERTIFICATION l DISTRICUTION SYSTEMS DESIGN GUIDE l If the temperature distribution in the pipe is nonlinear, the above curvature formula is only approximate and the nonlinear distribution should be considered in terms of its effect on curvature and local thermal stresses. This may be done by means of a finite element analysis comprised of a heat transfer analysis to determine the pipe wall temperature variation based on fluid temperature, followed by a thermal stress analysis to determine the initial pipe curvature and maximum stress intensity. This stress intensity should then be used in Equation 11 of the ASME Boiler and Pressure Vessel Code, Section III, Subsection NB-3650 as the nonlinear through-wall temperature gradient stress. Thace analyses consider both steady state and transient conditions.
7.1.4.3 Seismic Analysis
~
Seismic analysis of a piping system generally involves bo* dynamic and static evaluations. A dynamic analysis is r srmed to evaluate the inertia loads developed as the mass of the piping is accelerated due to seismic motion. The static analysis is performed to determine loading resulting from differential seismic movements of structures or large lines to which piping is attached.
7.1.4.3.1 Static Analysis Standard seismic analysis is a dynamic analysis using the modal superposition and response spectrum method. The design response spectra for earthquake ground motion indicate that at a frequency higher than the frequency corresponding to the zero period acceleration (ZPA), all modes respond like a rigid body without amplification. This cut-of f frequency defines the rigid range. If a piping system is so rigidly supported that its lowest natural frequency is higher than the frequency corresponding to the ZPA, then the system will respond like a rigid body. The maximum effect is due to an inertia force equal to the maximum floor acceleration, and therefore, a static analysis is sufficient for predicting the maximum effect due to an earthquake.
The analysis is similar to a gravity analysis. Attention should te paid to the following points in performing the analysis:
A. Inertia loads should be applied separately in the x, y, and z directions, and the results of the . 3 separate analyses combined by SRSS. The accelerations are obtained from the respective floor response spectra with values corresponding to the zero period.
B. The active supports are seismic supports, rather than gravity supports (i.e., snubbers will be active and low stiffness spring hangers inactive).
DRAFT 7-12 July 25, 1992
- ~ ,
SYSTEM 80+C DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 7.1.4.3.2 Dynamic Analysis 7.1.4.3.2.1 Response Spectrum Analysis 7.1.4.3.2.1.1 General The response of a flexible system to seismic forces depends upon its natural frequencies and the frequencies of excitation. For these systems, it is necessary to know the natural frequencies, and the seismic excitation which is usually defined as acceleration response spectrum. The development of response spectra for piping systems must be consistent with the goal of a standardized piping support system, stated in Section 6.2.3.1.
To determine the system natural frequencies, each pipe should be L idealized as a mathematical model consisting of lumped masses connected by clastic members. Lumped masses should be located at carefully selected points in order to adequately represent . the dynamic and elastic characteristics of the pipe system. Using the elastic properties of the pipe, the flexibility for the pipe should be determined. The flexibility calculations should include the ef fects of torsional, bending, shear, and axial deformations (i.e. ,
the degrees of freedom) . - Node point spacing should be selected to obtain accurate dynamic results. As a mininum, the number of degrecs of freedom should be taken as equal to twice the number of modes with frequencies less than the frequency corresponding to the ZPA.
Once the flexibility and mass of the mathematical me lol are calculated, the frequencies and mode shapert for all significant
' modes of vibration should be determined. Piping stresses and displacements should then be determined utilizing standard modal response spectra analysjs techniques.
! 7.1.4.3.2.1.2 Response Spectrum A response spectrum is a carve which represents the peak acceleration response verses frequency of a single - degree of s
freedom spring mass system which is excited by an carthquake motion time history. It is a measure of how a structural system with j
certain natural frequen<2es will respond to an earthquake applied at its supports.
The response spectra curves for System 80+ have been developed using several ground motion time history analyses. These analyses were used to cover a range of possible soil conditions. The resulting floor response spectra may be enveloped or considered in subgroups up to individually in the seismic analysis to account for all of the various soil cases; Most analyses will consist of multiple supports with different characteristic response spectrum. To account for this, the applienble response spectra for all structures and elevations DRAFT 7-13 July 31, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE supporting the pipe in the dynamic model may be enveloped to determine the response spectra for that piping, j
)
If this method is determined to be overly conservative, a multiple- i
, support spectra method may be used. The response spectrum of the l individual support locations may be input separately with the response due to each support combined in a conservative manner.
This method should not be used in combination with variable damping.
7.1.4.3.2.1.3 Spectrum Peak Broadening To account for possible uncertainties, the initially computed floor 4 response spectra are usually smoothed, and peaks associated with the structural frequencies are widened. The method used to determine the amount of peak widening, associated with ~ the structural frequency, should be as detailed in ASME Code,Section III, Division I, Appendix N, Section N-1226.3.
'/ . l . 4 . 3 . 2 .1. 4 Damping Damping values are provided in CESSAR-DC, Section 3.7.1.3 and are summarized below; OBE SSE Piping diameter s 12" 1% 2%
Piping diameter > 12" 2% 3%
Alternately, when using response spectra analyses, variable damping values in accordance with the requirements and limitations of the ASME Code Case N-411-1 " Alternative Damping Values for Response Spectra Analysis of class 1, 2, and 3 Piping,Section III, Division.
I" is acceptable. However, no combination of the.two damping criteria shall be used. The variable damping curve is provided in CESSAR-DC, Table 3.7-41.
l 7.1.4.3.2.1.5 Modal Cutoff and Rigid Range' Acceleration Effects s
The number of modes included in the analysis should be chosen to correspond with the range of seismic excitation frequencies up to
- the frequency corresponding to the ZPA. There is no limit on the number of. modes. The number of modes included in the analysis should be selected so that the response from the remaining higher modes does not result in more than a 10% increase in total system response.
At modal frequencies above the frequency corresponding to the ZPA, pipe members are considered cigid. The acceleration associated with these rigid modes is usually small. However, in certain
- situations the response to high frequency modes can significantly affect support loads, particul.arly axial restraints on long runs.
The effects of rigid range accelerations may be evaluated by I
DRAFT 7-14 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 7.1.4.3.2 Dynamic Analysis 7.1.4.3.2.1 Response Spectrum Analysis
-7.1.4.3.2.1.1 General The response of a flexible system to seismic forces depends upon its natural frequencies and the frequencies of excitation. For these systems, it is necessary to know the natural frequencies, and the seismic excitation which is usually defined as acceleration response spectrum.
To determine the system natural frequencies, each pipe should be ^
idealized as a mathematical model consisting of lumped masses connected by elastic members. Lumped masses should be located at carefully selected points in order to adequately represent 'the dynamic and elastic characteristics of the pipe system. Using the elastic properties of the pipe, the flexibility for_ the pipe should-be determined. The flexibility calculations should include the effects of torsional, bending, shear, and axial deformations (i.e.,
the degrees of freedom). Node point spacing should be selected to obtain accurate dynamic results. As a minimum, the ~ number of degrees of freedom should be taken as equal to twice the number of modes with frequencies less than the frequency corresponding to the-ZPA.
Once the flexibility and mass of the mathematical model are calculated, the frequencies and mode shapes for all significant modes of vibration should be determined. Piping stresses and displacements should then be determined utilizing standard modal response spectra analysis techniques.
7.1.4.3.2.1.2 Response Spectrum A response spectrum is a curve which represents the peak acceleration response verses frequency of a single degree of freedom spring mass systen. which is excited b:~ an earthquake motion time history. It is a measure of how a st_uctural system with certain natural frequencies will respond to an earthquake applied at its supports.
The response spectra curves for System 80+ have been developed using several ground motion time history analyses. These analyses were used to cover a range of possible soil conditions. The resulting floor response spectra may be enveloped or considered in-subgroups up to individually in the seismic analysis to account for all of the various soil cases.
Most analyses will consist of multiple supports with different characteristic response spectrum. To account f~o r this, the applicable response spectra for all structures and elevations DRAFT 7-13 July 25, 1992
1 l
SYSTEM ~80+5 DESIGN CERTIFICATION j DISTRIEUTION SYSTEMS DESIGN GUIDE supporting the pipe in the - dynamic model may be enveloped to determine the-response spectra for that piping.
If this method is determined to be overly conservative, a multiple-support spectra method may be used. Ine response spectrum-of the individual support locations may be input separately with the response due to each support combined in a conservative manner.
This method should not be used in combination with variable damping.
7.1.4.3.2.1.3 Spectrum Peak-Broadening To account for possible uncertainties, the initially compute'd flour response spectra are usually smoothed, and peaks associated with the structural frequencies are widened. The mett.od ' used to determine the amount of peak widening, associated with ~ the structural frequency, should be as detailed in ASME Code,Section III, Division I, Appendix N, Section N-1226.3.
7.1.4.3.2.1.4 Damping Damping values are provided in CESSAR-DC, Section 3.7.1.3 and are summarized below; OBE SSE Piping diameter 5 12" 1% 2%
Piping diameter > 12" 2% 3%
Alternately, when using response spectra analyses, variable damping values in accordance with the requirements and limitations of the ASME Code Case N-411-1 " Alternative Damping Values for Response Spectra Analysis of Class 1, -2. and 3 Piping,Section III, Division I" is acceptable. However, no combination of the two damping criteria shall be used. The variable damping curve is provided in CESSAR-DC, Table 3.7-41.
7.1.4.3.2.1.5 Modal Cutoff anc Rigid Range Acceleration Effects The number of modes included in the analysis should be chosen to correspond with the range of-seismic excitation frequencies-up to the frequency corresponding to the ZPA. There is no limit on the -
number of. modes. The number of modes included in the analysis should be selected so that the response from the remaining higher modes does not result in more than a 10% increase in. total system response.
At modal frequencies above the frequency corresponding to the ZPA, pipe members are considered rigid. .The acceleration associated with these rigid modes is usually small. . However, in - certain situations the response to high frequency modes can significantly affect support loads, particularly axial restraints on long runs.
The effects of ricid range ' accelerations may be evaluated by DRAFT 7-14 July 25, 1992
. - -- -- - - - . a. .
SYSTEN 80+" DESIGN CERTIFICATION DISTRIBUTION-SYSTEMS DESIGN-GUIDE approximating the higher mode response. using the spectral' acceleration ac the frequency corresponding to the- ZPA and combining this response with the dynamic analysis results in an additional mode (using the square root of the sum of the squares, SRSS).
7.1.4.3.2.1.6 Modal and Direction Result Combination As stated in CESSAR-DC, Section 3.7.3.7, the seismic response of each mode shall be calculated and combined with the other modal responses using the methods described in Regulatory Guide 1.92,
" Combining Modal Responses and Spatial Components in Seismic Response Analysis".
If the modes are not closely spaced (two consecutive modes _are defined as closely spaced if their frequencies differ from each other by 10 percent or less of the lower. frequency), the results may -be combined by the square root of the sum of the squares (SRSS). Closely spaced modes should be combined by one of the following. methods: (1) Grouping Method, (2) Ten Percent Method, or, (3) Double sur Method.
The responses due to each of the three separate directions of seismic excitation should be combined by SRSS.
7.1.4.3.2.1.7 Seismic Anchor Movements The effects of seismic anchor motion shall be considered in the seismic analysis. For models with piping in more than one building, it should be assumed that the buildings move 180* out of phase. Movements within all buildings except the Reactor Building should be assumed to be in phase. Within the Reactor Building there can be differential movements between the' Reactor Building, the Containment Vessel, Reactor Interior Structures,. and the N3GS.
These movements, when applicable, should be assumed-to act 180' out of phase. The resulting relative movement should be applied as static support displacements with all dynamic ~ supports active.-
Support loads shall be obtained and defined for both OBE and SSE motions.
7.1.4.3.2.1.8 Fatigue The cyclic load basis for fatigue analysis vf the OBE earthquake shall be a minimum of 75 full load- cycles for Class 1 piping systems.
7.1.4.3.2.2 Time History Analysis 7.1.4.3.2.2.1 General DRAFT 7-15 July 25, 1992 l
SYSTEM 80+5 DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE Time history analysis may be used as an alternative method to response spectrum analysis for any piping system.
For those piping systems analyzed -by time _ history methods, development of mathematical models, which define flexibility and mass, and calculation of natural frequencies and mode shapes, as described in Section 7.1.4.3.2.1.1, should first be performed.
7.1.4.3.2.2.2 Piping Dynamically Decoupled from the NSSS Most piping systems can be dynamically decoupled from the nuclear steam supply system (NSSS), following the guidelines of Section 7.1.5.2.2. The surge line, which is functionally part of the NSSS, is included in those piping systems which can be shown to meet the decoupling criteria, and should therefore be analyzed separately from the rest of the NSSS.
The solution of the differential equations of motion, which describe the dynamic response of a system to a seismic excitation, can be obtained by the method of modal superposition or by the method of direct integrations, using time history analysis. These methocs are described in CESSAR-DC, Section 3.7.2.1.1.2.
The mathematical model should be subjected to seismic excitations at the anchor points (terminal ends) and at building supports. For statistically independent earthquake motions, input excitations in all three translation directions and, as applicable, in all three rotational directions should be applied simultaneously to the anchor points and building supports.
Input of multiple time history excitations, which allow calculation of the effects of both differential motion and inertia, should normally be used in a multiply supported system such as a piping system. An acceptable alternate time history method, as described in ASME Code,Section III, Division I, Appendix M, Section N-1228.4, is to input an " envelope" time history excitation' to calculate the inertia response, and separately to determine the effects of differential support motion using a static analysis.
The ASME B&PV Code defines the envelope excitation as a time history whose response spectrum envelopes the response spectra for the individual support motions.
7.1.4.3.2.2.3 Piping Dynamically Coupleii to the NSSS The only piping system that is dynamically coupled to the NSSS-for the purpose of structural analysis is the main coolant loop piping.
The main coolant loop piping should be seismically analyzed as an integral part of the reactor coolant system structure, using methods described in CESSAR-DC, Sections 3.7.2.1.2 and 3.7.2.6.2.
DRAFT 7-16 July 25, 1992 l l
SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE-7,1.4.4 Eculoment Nozzles s
The following effects of equipment nozzles should be considered in the analyses and included where appropriate:
- Equipment response spectra
= Equipment nozzle displacements and rotations
- Equipment nozzle flexibility 7.1.4.5 Wind / Tornado Analysis Exposed piping shall be designed to withstand forces generated by wind and tornados. Maximum wind speeds provided in CESSAR-DC, Section 3.3 are listed below; A. Wind loading: 130 mph maximum wind speed B. Tornado loading:
1, 330 mph maximum wind speed
- 2. 260 mph rotational wind velocity 3, 70 mph translational wind velocity Tornado loads are based upon the NRC Staff interim position based on NRC Regulatory Guide 1.76, " Design Basic Tornado for Nuclear Power Plants".
7.1.4.6 Fluid Transient Analysis Transient fluid dynamic loadings on piping should be evaluated and the resulting loads includec in the piping analysis. The loads considered should be those significant loads due to fast valve closure, steam hammer, water hammer, relief valve discharge, and multiple relief valve discharge. Potential loadings should be evaluated and defined for each problem on a case-by-case basis.
Multiple safety valve _ discharges should be analyzed so as to
- maximize piping stresses and support / restraint design loads unless another discharge sequence can be justified. Discharge sequences considered should include the possibility of the instantaneous and simultaneous discharge of all valves in the same vicinity. The !
following represents acceptable analysis methods. Other methods i such as characteristics computer programs may be used where i justified.
7.1.4.6.1 Safety / Relief Valve Thrust Safety / relief valves produce transient and steady-state loads on the valve inlet piping and discharge piping (if used). The thrust load, F, is a function of fluid type (water or steam), design pressure, and valve throat area. An acceptable method of calculating the valve thrust loads is as follows.
DRAFT 7-17 July 25, 1992
SYSTEN 80+* DESIGN CERTIFICATION DISTRIGUTION SYSTEMS DESIGN GUIDE A. Water Discharge:
l Fsrarrc=0. 0 022 [ (Eqn. 7.1-2)
Where: GPM = rated valve discharge in gallons per minute ID = inside diameter of the discharge pipe in inches A dynamic load factor of two should be included for the dynamic loading unless a lower value is justified.
B. Steam Discharge:
The procedure of ASME B&PV Code,Section III, Appendix 0, should be used, with the caution that negative (below atmospheric) discharge pressures are meaningless and the equation does not apply for those cases.
Relf 3f valves cause both dynamic and static loading conditions. To simplify analysis, however, essentially all relief valve thrust loads are evaluated statically. Closed discharge and piped relief valves have an additional complicating factor since transient forces develop at each intermediate turn in the-piping during the initial phase when the flow along the pipe is being established.
These transient loads should be treated as water / steam hammer. As the transient phase ends, all of the intermediate forces cancel each other out, leaving only the steady state thrust force at the exit point of the fluid from the discharge system. For closed discharge systems, the steady state thrust force is zero at the valve outlet.
Dynamic relief valve thrust loads should be applied to the piping model as static loads with snubbers active and a dynamic load factor applied to the loads.
7.1.4.6.2 Water and Steam Hammer Analysis Water and steam hammer are both dynamic loading conditions on the piping. Forcing functions, using actual time history analyses, may be used in the dynamic analysis. However, the following simplified conservative approximations of the forces may be used-in a static evaluation.
The simplified method described below determines the worst net force developed in a segment of piping and applies it assuming it can occur in either direction along the local 'x' axis of the pipe.
Thia net force that develops depends on flow rates, fluid velocities, valve closing time, the length of straight runs of pipe, and the fluid involved.
DRAFT 7-10 July 25, 1992
-. - -- - - = - .
i SYSTEM 80+"^ DESIGN; CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE
,' 7.1.4.6.2.1 Water Hammer Forces Two equations exist -for determining the resultant force, F , on any straight segment of piping due to water-hammer. The proper one to
, use depends on the ratio of L/L, for -the pipe 1 segment in question, where L-(ft) is the length of straight pipe-of the segment and L.
(ft)_ is the distance travelled by the shock wave during the valve closure. L is available from the_ piping drawings and is shown as--
l an example for piping run 2 on Figure 7.1.4-1. The distance i
travelled by the shock wave (1) may be calculated:
L,=cx c (Eqn. 7.1-3) l ~
Where: c = sonic velocity in water ' (4,700 ft/sec) t = valve closure time (sec)-
j- A. For (L/ L,) < 1.0 F,= MS -(Eqn. 7.1-4) 9 Where: h = mass flew rate of water (1bm/sec) c = 4,700 (ft/sec) i g = 32.174 lbm-ft/lbf-sec 2 F, = resultant net force -(1bs)_ along pipe run B. For (L/L ) > 1.0 F,= M (Eqn. 7.1-5) gc Wheretheabohedefined_termsapplyand:
L -= length of straight _ pipe run (ft).
t = valve closure time (sec)
One of the above equations should be used to calculatec the net force to be applied for each straight segment of piping until a point is reached where the pressure waves are damped out at a tank,-
closed valve, equipment ' connection, or . connection . - to a large-header.
DRAFT 7-19 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN' GUIDE 7.1.4.6.2.2 Steam Hammer Forces Since steam is a compressible fluid, .the calculation of resultant forces along each.-straight run can be performed by the following six steps and terms:
A. Terms-In = steam mass- flow rate (lbm/sec)
P = design pressure (psig)
T = steam temperature.-(saturated )lat P (*F) y = specific volume of steam;at T and P (ft 3/lbm) vioco = specific volume at P and 1000'F (ft 3/lbm)
L. = distance travelled by. shock wave (ft) c = sonic velocity at P and T-(ft/sec)
F. = net force exerted on pipe segment (lbs)-
t = valve closure time (sec)
TF. = temperature factor-V = steam velocity _ (ft/sec) 3 A = flow area of-pipe (in )-
L = pipe length between turns-(ft)
B. Net Force Calculation
- 1. Compute temperature factor (TF)'
'V ioco (Eqn . 7.1-6) g.h y
- 2. Calculate length (Ls) over which the pressure wave propagates during. the valve closure time -(t)
L,=cx c -
- 3. Calculate initial steam velocity- (V)
V= M - (Eqn ~. 7.1-7)
A-
, 4. .
Using Figure 7.1.4'2, pick the curve (or interpolate a curve) that represents the steam velocity (V) above._
- From this curve-determine-the_ slope at the steepest; .;
section of the plot. At this : steepest . point, . the :
' abscissa difference. is the ratio JL/L,. Multiplying' ,
l l ---
DRAFT 7-20 July 25,.1992 l.
SYSTEM 80+" DESIGN CERTIFICATION DISTRIOUTICN SYSTEMS DESIGN GUIDE this abscissa difference by the slope provides the pressure rise ratio AP/P:
(Abscissa Difference) x (Slope) = AP/P
- 5. The force exerted along any segment is then:
F=PxTFxA W i P4 (Eqn. 7.1-8)
- 6. As with water hammer, this force should be determined for each straight segment of pipe until a point is reached (equipment, tank, closed valve, etc.) where the pressure wave would be damped.
7.1.4.7 Pice Break Analysis Pipe break loads are any loads that are applied to unbroken pipe resulting from ruptures of nearby piping. Pipe break loadings include, but are not limited to, the effects of the following: pipe whip, jet impingement, dif ferential pressure, - temperature increase (localized or overall), and support / anchor ' movement (including reacter coolant loop and containment vessel). ' Effects of a ruptured pipe on other portions of itself need not be considered, except to demonstrate that a whipping pipe is restrained.
In general, pipe break loads are defined for each piping problem on a case-by-case basis. These loads should be applied by the piping analyst as applicable to the appropriate piping problem. See Section 7.1.8 for further details of postulated pipe breaks. Pipe break loadings due to two or more assumed pipe breaks 2.lall be considered to act individually as separate events.
l l 7.1.4.8 Hich Enerav and Moderate Enerov Recuirements l
l High and moderate energy piping systems shall be evaluated for postulated pipe breaks. Intermediate break .. cations are based on potential high stresses and fatigue limits determined by the piping stress analysis results. For the postulated pipe break evaluation requirements see Section 7.1.8.
7.1.4.9 Non-Ricid Valves Normally, valves _are specified to be rigid. Non-rigid valves f (indicating that the valve has modes of vibration < ZPA) are l
! identified by the applicable valve seismic report. The effects of 4 the no'n-rigid valve should be considered in the piping analysis.
DRAFT 7-21 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATT.ON DISTRIBUTION SYSTEMS DESIGN GUIDE FIGURE 7.1.4-1 Watg/ Steam Hammer Force 1 f
5
- =:~ >
5 F
EQUIPMENT F 6 N5 t
F 4 3 m
F N3 F
8 4
e F
7 2 L F RAPID CLOSING VALVE N4 1 F
L A -
F 2~ y3 F)
N1 o
9 F
N2 F3 = Time dependent force developed at change in direction.
= Net resultant force along axis of pipe at worst time Fut (i.e., maximum dif ference between opposing F 's) .1 July 25, 1992 7-22 DWT
4 SYSTEM 80+" DESIGN CERTIFICATION
- DISTRIBUTION SYSTEMS DESIGN GUIDE i
FIGURE 7.1.4-2 l
Percent Pressure Rise vs. Valve Closina Time ;
16 .
1
. s s 1 r
- j. Percent ** essure Rise
- - vs.
Valve Closing Time
! ja (For various initial flow velocities)
N F , 250 (ft/sec) i _
I i
j 12 i
~ , -190-- $8 e
l (ft/sec)
- i a i
x 10
/ $=
i
~ x t $ % '
, E .o
' u 8
\I 140
- (ft/sec) !
- a. - 3 m
b 6 / ! %
I*
/ h o
4
. />
j 2
l/
~
/
n AV t 1 I O- 0.2 0.4 0.6 - 0.8 1.0
- Valve Closing. Time-7-23 July 25, 1992 DRAFT
~
SYSTEM 80+" D1GIGN CERTIFICATION i
DISTRICUTION SYSTEMS DESIGN GUIDE !
j.
s 7.1.4.10- Excansion Joints Expansion joints allow limited relative -lateral 'and? -axial displacements and bending rotations.between the ends of-the joint, depending on the-type of joint--in use.- Expansion joints should be- 'I considered in the analysis, l
f 7.1.5 ANALYSIS TECHNIQUES l 7.1.5.1 Model Boundaries t
Piping models ' ideally run from anchor to anchor . (equipmentinozzle,-
or penetration). - Where this is not feasible, the. piping-may1be i separated by decoupling overlapping, isolation, or in-line anchors:
as described in the following' subsections to. form more manageable models for analysis. These' subsections present minimum-requirements. If the piping cannot be separated to form smaller analysis models by these methods, the analyst-may consider the use of an - intermediate a n c h o r _' t o separate models subject to :the-considerations of'Section 7.1.5.5.
7.1.5.2 Decouolinc 7.1.5.2.1 General- ,
Small branch lines may be decoupled from . larger run= piping regardless - of seismic classification. Decoupling may_ also be applied.for in-line pipe size changes (such as at a reducer ~ or reducing insert). For co'nsistency-with the following text, the smaller line should be considered the " branch" and the larger line should be considered the "run". -- To ' be - decoupled, piping _should meet the size, section modulus, or- moment of inertia ratios as detailed in the following paragraphs.
7.1.5.2.2 Decoupling criteria Branch lines meeting the following criteria may be decoupled from
~
the main run:
A. D /D, 's 0. 25, or B. Z /Z, 5 _0.10, or C. I /I, s 0.04 Where: D. = branch nominal pipe size-D, = . run nominal -pipe size Z. = branch _section modulus
'Z, = run section modulus In = branch moment-of, inertia I, = run moment of inertia DRAFT i July 25, 19_92L l
1
+A SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE An appropriate stress intensity factor (SIF) should be included on the branch and main run lines at the point where the piping is decoupled. Mass effects of the branch line should be considered in the analysis of the run line and-includad, if'significant. The branch point should be considered as an anchor in the analysis of the branch pipe. Thermal and seismic anchor movement analyses of the decoupled branch lines snould be performed with the thermal, seismic inertial, seismic anchor movement (SAM), or pipe break movements of the larger pipe header applied as anchor displacements and/or rotations to the smaller branch line if these movements are significant.
Tiping may also be decospled at flexible hose provided each interfacing analysis considers the flexible hose weight and significant stif fness, and the flexible hose qualifies for the net end displacements of the interfacing analysis problems. Analy' sis results of the interfacing problems do not have to be combined.
The flexible hose should not be allowed to experience large tensile loads.
7.1.5.3 overlapoina 7.1.5.3.1 General Overlapping is used to separate seismically analyzed piping problems. Isolation of non-seismic piping from seismic piping is addressed in Section 7.1.5.4.
Seistic piping that cannot be separated by decoupling as described in Section 7.1.5.2 may be separated using an overlap region. The overlap region should have enough rigid restraints and include enough bends in three directions to prevent the transmission of motion due to seismic excitation from one end to the other. The following criteria present minimum requirements which should be l
upgraded if required to satisfy this condition.
r 7.1.5.3.2 Overlap Criteria A section of piping to be considered an overlap region should meet the following criteria:
A. The section contains a minimum of four (4) restraints in each of three perpendicular directions. If a branch is encountered, the balance of restraints needed beyond that point should be included on all lines joining at the branch.
B. The restraints in the section are so spaced that the pipe i span between any two restraints, taken as simply supported beams, have a fundamental natural frequency- (cending and torsion) not less than the frequency corresponding to the i ZPA.
DBAFT 7-25 July 25, 1992
- SYSTEM'80+" DESIGN CERTIFICATION l i DISTRIEUTION SYSTEMS DESIGN
- GUIDE- l l
j- C. In;11eu of criteria-B, a dynamic analysis of!the-overlap-
- region should - be --made - with pinned _-boundaries extended f- beyond. the overlap _ region either _ to -the1 next. actual support or-to_a_ span length equal to the largest? span
, length within . the _ region. The fundamental frequency-determined from this analysi_s-should be greater than the
, frequency corresponding to-the:ZPA.-
)
i The overlap region should contain at least one change in direction to filter torsional- effects. The overlap piping should be included
- in all models adjacent to the overlap region. -An-axial restraint l on _a run may be counted effective _ at each point of lateral-
- restraint on that same -~1n. Hanger design loads and movements in-5 the overlap region nou. 2 be obtained by enveloping the:results-of-all models adjacent .on che overlap -region. Pipe stresses and valve
- accelerations should be checked in each separate analysis.
i 1 7.1.5.3.2.1 Restrained Elbow (or_ Tee)
) Adequately restrained elbows or restrained --tees may be used to-t terminate or separate- analysis- models. Restrained elbows and restrained tees should meet the criteria of Figures 7.1.5-1 and j 7.1.5-2, respectively. Results of'all analyses should be combined-to obtain pipe stresses and hanger loads for the restrained elbow:
- and restrained tee _ configurations.
i i 7.1.5.4 In-line Anchors An in-line anchor is a device restricting all six d % ees of.
- freedom, thereby isolating-each run' . In-line anchors should'only
- be used to separate piping models, if' practical, based - on the i following considerations:
{ A. Anchors could be impractical, especially on large diameter a piping ( >4"- nominal pipe size, NPS) or_ on lines with high 5
thermal and/or seismic movements.
! B. The addition of . anchors can . add terminal- end . ' break
- locations to high and moderate energy piping.
C. The use of anchors can be limited by h'igh piping-thermal--
{_' expansion loadstor the practicality of the anchor-design 4 and installation.
i D. Anchor load results from the piping on both-sides of an i anchor should be. combined to obtain the. design. loads for the anchor. If-the piping-on one side of the anchor _is unanalyzed, appropriate loads should _ be developed to
- represent the.unanalyzed pipe. As-an example, plastic
~
collapse moments for the unanalyzed side may be used.
}-
{
I DRAFT 7-26 July 25, 1992 J
. . . - _ , .~ . .. - .. - -
I t
-SYSTEM 80+"' DESIGN CERTIFICATION DISTRIBUTION-SYSTEMS DESIGN GUIDE 4
FIGURE 7,1.5-1 Restrained Elbow.
i s
4 i
i J a
)
- - \
1- i ,(
Z g I
4 l
i i
4 j' Dimensions f t and tz are defined as follows:
i
- NOMINAL MINIMUM -MAXIMUM f 3 6" Weld Clearance .- 6 "
J.
f L/4 L/8 L/4 Where: L = ASME B31.1 Recommended Support Span per Table 121.5.
4 DRAFT 7-27 July 25, 1992 i
SYSTEM 80+5 DESIGN CERTIFICATION.
DISTRIHUTION-SYSTEMS DESIGN GUIDE
-1 FIGURE 7.1.5-2 Restrained Tee d
St
- L Et a
a b .X l
/ k' Rg
& '/2 1 2t Dimensions i t and f 2 are defined as follows:-
NOMINAL MINIMUM MAXIMUM i 2 6" Weld Clearance 6" i 2 L/4 L/8 L/4 Where: L = A3ME B31.1: Recommended Support Span per Table 121.5.
b I.
DRAFT 7-28 July 25, 1992 l
- . . ~ . _ . . . _ _ _ . _ - _ . . . - . . . . .
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS-DESIGN GUIDE s
7.1.5.5 Suecort-Considerations t
[ The- proper participation and orientation o'f each support / restraint should be included in the piping analysis. Par _ticipation should be consistent with how the support type performs during the_ loadings 4 under consideration. Some loading conditions _ create pipe movements that could affect the -analyzed _ support . orientation, such as vertical -supports with large lateral thermal movements. The effects of such pipe movements on the analyzed support orientation should be evaluated.
7.1.6 ACCEPTANCE CRITERIA 7.1.6.1 ASME Class 1 Pipinc
- The allowable stress limits for the specified loading combinations-
. for ASME Class 1 piping are shown in Tables 7.1.3-1 and 7.1.3-2.
i 7.1.6.2 ASME Class 2 acd 3 Pioino 4
The allowable stress limits for the specified loading combinations for ASME Class 2 and 3 piping are shown in Table 7.1.3-3.
1 7.1.6.3 Allowable Nozzle Loads
- Loads - applied to equipment nozzles shall' not ' exceed allowable values provided by the equipment vendor. In ' lieu of specific.
values, generic allowable equipment nozzle -loads may be used l
provided the equipment is specified to these design nozzle load
- values.
7.1.6.4 Allowable Penetration Loads
! Loads and displacements on containment penetration assemblies, as
! shown in CESSAR-DC, Figure 3.8-2, ~ shall meet manufacturer's l allowables.
7.1.6.5 Welded Attachments Per ASME Section. III, Subarticle NC/ND -3645, external and internal attachments to piping shall. be designed so a s -- n o t to cause ,
flattening of the pipe,-excessive' localize _d bending _ stresses, or-l
)
' harmful thermal gradients in the pipe wall. It is-important that such-attachments be.so_ designed to minimize stress concentrations i in applications where-the number of stress cycles, due-either.to pressure or t.hermal' effect, is relatively large.for the _ expected i life of the equipment.
, Local stresses ~ due- to all support loads acting on a- welded
! attachment should be evaluated and added directly to the nominal pipe stresses-at the point of the attachment. The sum of- the
. stresses shall be compared against the allowable stresses given in i
l
- DRAFT 7 July 25, 1992
SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE Tables 7.1.3-2 and 7.1.3-3. Methods for evaluating local stresses due to welded attachments are provided in ASME Code Cases N-318 and H-392.
7.1.6.6 Functional Capability Requirements CESSAR-DC, Section 3.9.3.1.4.2 requires that ASME Class 2 and 3 piping be evaluated for functional capability. Appendix 7B provides the functional capability requirements for ASME Class 2 and 3 stainless steel elbows as stated in Texas Utilities' lotter TXX 3423, 7.1.6.7 Valve Reauirements 4 Valve accelerations should meet the allowable manu f acturer's requirements for seismic acceleration. The loads on supports attached to valve operators should also be evaluated.
7.1.6.8 Exoansion Joint Recuirements Expansion joints should be evaluated to ensure compliance with vendor allowables.
7.1.7 PIPE SUPPORT DESIGN REQUIREMF"TS 7.1.7.1 General The design of pipe supports should meet the intended functional requirements of the stress analysis as well as meeting the specified stress limits for the support components. Support components may include typical structural steel members as well as manufactured catalog items for typical support components.
Supports are idealized in the piping analysis as providing restraint in the analyzed direction while providing unrestricted movement in the unrestrained direction. Since the design of supports cannot completely duplicate the idealized condition, 4
supports should be designed to minimize their effects on the piping analysis. Additionally, the support design should not invalidate any assumptions used in the analysis of the piping system.
In addition to loads defined by the stress analysis, any additional forces the support are subjected to should be considered in the support qualification.
7.1.7.2 Desian Considerations j 7.1.7.2.1 Deadweight Loads Gravity loads of the pipe are typically restrained by two types of I supports. The piping analysis will define whether the support !
should be designed as a rigid or flexible support. Flexible DRAFT 7-30 July 25, 1992
SYSTEM 80+* DESIGN CERTIk tATION ,
DISTRIBUTION SYSTEMS DESIGN JUIDE l l
supports are usually specified when the pipe must be restrained for its gravity weight, however must remain free to move during thermal expansion. Vendor supplied spring components with specified spring constants are typically provided in this application.
In addition to gravity loads from the piping analysis, the deadweight of the support itself should be considered in the support qualification.
7.1.7.2.2 Thermal Loads Temperature changes within the piping system, including thermal stratification, will cause the pipe to thermally expand. Thermal loads are induced into supports which restrain the piping system from being able to freely expand. Additional thermal loads could be a result of " anchor" displacements. Movements at the terminal end points of the piping system, such as branch lines and vessels, will induce loads into supports which resist these movements.
These forces are usually referred to as thermal anchor movements (TAM). All possible- thermal conditions, including ambient thermal, should be evaluated when combining thermal loads with other load cases to obtain the worst loading on the supports. The pipe will also experience rad' .1 expansion due to temperature increases. To minimize local acresses within the pipe, supports should be designed to allow for this expansion. See Section 7.1.7.2.10 concerning support gaps.
Pipe supports should also be evaluated for environmental thermal conditions. Temperature increases in the area around the support will cause the support itself to tend to thermally expand. In addition, local high temperatures can exist close to the pipe wall.
Support elements which are subjected to these elevated temperatures should be evaluated for thermal effects. Material property values consistent with the associated temperature should be used.
Thermal expansion of the pipe support and/or the building structure from which the support is attached should be evaluated for its effects on the piping analysis.
7.1.7.2.3 Seismic Loads The building response to earthquake motion will cause seismic acceleration of the piping system. Earthquake inertia forces are applied to supports that restrain the seismic movement of the piping system. Additional seismic movements _could be caused by seisfic acceleration of terminal end points of the piping - system such as branch lines and vessels. These forces are usually referred to as seisnic anchor movements (SAM).
The response of the support itself due to seismic acceleration should also be evaluated. Typically, the inertia response of the support mass would be evaluated using a response spectrum analysis DRAFT 7-31 July 25, 1992
SYSTEM 80+5 DESIGN CERTIFICATION DISTRIOUTION SYSTEMS DESIGN GUIDE similar to the piping analysis as described in Section 7.1.4.3.2.1.
Damping values for welded and bolted structures are provided in CESSAR-DC, Table 3.7-1.
7.1.7.2.4 Dynamic Fluid Loads Dynamic fluid loads are a result of fluid transients due to safety relief valve thrust, water and steam hammer. These events are evaluated in the piping analysis. Supports should be designed to meet the requirements of the piping analysis.
7.1.7.2.5 Wind / Tornado Loads Exposed piping and support structures shall be designed to withstand forces generated by wind and tornados. Wind and tornado
.oading on the piping should be evaluated in the piping analysis.
The effects of wind and tornado on the support structure shall also .
be considered in the support qualification. Design wind speeds are l provided in CESSAn-DC, Section 3.3.
7.1.7.2.6 Missile Loads Supports subjected to loads described in CESSAR-DC, Section 3.5.1 should be evaluated for the effects of missiles.
7.1.7.2.7 Pipe Break Loads The dynamic effects of pipe breaks on the piping cystem shall be considered in the piping analysis unless eliminated by leak-before-break (LBB) methodology. The effects of pipe whip, jet impingement, and temperature increases on the support structure should be considered in the support qualification.
7.1.7.2.8 Support Stiffness Supports may be rnodeled in the piping analysis by using the .4ctual support stiffness values or by using rigid stiffness values. If using tne actual qupport stiffnesses, the flexibility of all support components }s well se the effects of the building structure should be included in the tctal stiffness value.
Rigid stiffness values are typically used. , Actual stiffness values for flexib'e supports (e.g., spring cans) are usually included in the piping analysic. . When using rigid stiffnesses, it is also important that all supports, in a given pipe analysis, be designed with a reasonably equal stiffness. This reduces the effects of load redistribution to stiffer supports due to the deflection of the more flexible supports.
Since supports are usually modeled with one stiffness value for both directions of a support axis, supports should be designed.to have similar stiffnesses in both directions. Additionally, support DRAFT 7-32 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE stiffness in the unrest rained direction of the pipe should be considered to minimize the effects of seismic inertia loading of the support mass. i i
Additionally, the piping analysis may assume that supports are l sufficiently rigid in comparison to the pipe to allow decoupling of I the supports from the piping analysis. Therefore, rigid supports !
should be designed to ensur3 thi stiffness of the supports do not significantly affect the pipe frequency.
7.1.7.2.9 Friction .
Temperature changes in the piping system will cause movement in the unrestrained direction 'f the pipe. If the pipe is free to slide !
across a support, frictional forces will be developed between the l support surface and the pipe. The amount of frictional force devtloped as a function of the coefficient of frictior, of the sliding surfaces and the support stiffness in the direction of movement. Since friction is due to gradual movement of the pipe, such as thermal expansion, frictional forces should be considered
'n the support qualification under combined dcadweight and thermal loading only. Friction forces should be applied in both directions of thermal expansion.
Typically frictional forces are neglected in the analysis of the piping system because supports are designed to minimize the effects of friction on the piping analysis.
7.1.7.2.10 Support Gaps Gaps between the support and the restrained direction of the pipe create a non-linear situation which should be avoided. However for frame type supports built around the pipe, small gaps should be provided. These gaps allow for radial thermal expansion of the pipe as well as allowing for pipe rotatA0n. In order to neglect support gaps in the piping analysis, they are typically restricted to a total of 1/8" in the restrained direction. More restrictive gaps could be needed at supports close to sensitive equipment or where specific thermal or transient stops are specified. Gaps of these magnitudes are typically negligible and considered to be zero in the piping analysis.
Gaps in the unreFtrained d1Lection should be' specified large enough to accommodate tne maximum movement of the pips. Standarra practice is to provide an additional 1/2" gap to account for uncertainties in the piping analysis.
7.1.7.2.11 Support Orientation Supports should be provided in the direction required by the piping analysis. However, due to pipe movements, the orientation of the support axis cculd change during different plant conditions.
DRAFT 7-33 July 25, 1992
SYSTEN 80+" DESIGN CERTIFICATION DISTRIOUTION SYSTEMS DECION GUIDE Therefore, supports such as struts and snubbers should be designed to minimize the effects of the pipe movements.
7.1.7.2.12 Support Mass Typically the mass of the support is not considered in the piping analysis. Therefore, the weight of components supported by the pipe should be limited to the extent possible. For example, spring supports should include the weight of the components below the
- spring in the spring load setting, thus negating the weight that would have been supported by the pipe. However, due to the seismic response of the attached mass, supports which add substantxal mass to the pipe should be evaluated for the effects on the piping analysis.
7.1.7.2.13 Welded Pipe Attachments Welded attachments to the -pipe wall should be. avoided where possible. However, certain design requirements such as anchors or axial restraints could require the~use of welded lugs or trunnions.
All welded : attachments will require - the evaluation of the _ local stresses induced into the pipe. Materials used as welded attachments shall be compatible-with the piping _ material.-
7.1.7.3 Load Combinations f
Load combinations shall be in accordance with CESSAR-DC, Section 3.9.3.1 and are detailed in Table 7.1.7-1.
7.1.7.4 h.cceotance Criteria Stress limits for structural.nembers of pipe supports shall meet the requirements defined in ANSI /AISC N690, " Nuclear Facilities-Steel Safety-Related Structures for_ Design Fabrication' and Erection".
Manufactured catalog items should meet the requirements of MSS-SP-58, " Pipe Hangers and Supports-Hhtwrials, Design and Manufacture".
The application of catalog components should be consistent with the manufacturer's requirements and should meet the manufacturer's load rated capacities for the items.
Expansion anchors - and other steel embedmen'ts used in the support design'shall maet the requirements of ACI-349, " Code Requirements for Nuclear Safety Res.ted Concrete Structures".
7.1.7.5 Ju ri sdict ional - Bounda ries The jurisdict' tonal boundaries shall be_ as defined in ASME Code,Section III, Dubsection NF. However, the acceptance criteria as defined above should also be applicable for the qualification of support-components within_the NF boundaries.
DRAFT- 7-34 July 25, 1992 l
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE TABLE 7.1.7-1 Loadino Conditions and Load Combination Recruirements for ASME Code class 1, 2, and 3 Pipino Supports CONDITION LOAD COMBINATTON
- 1. Normal Condition Weight (Service Level A) Thermal C)
- 2. Upset Condition Weight (Service Level B) Thermal (1)
Dynamic riuid Loads (2)
OBE Inertia CBE Seismic Anchor Hovements or Wind (3)
- 3. Emergency Condition Weight (Service Level C) Thermal (1)
Dynamic riuid Loads (2)
SSE Inertia SSE Seismic Anchor Hovements or Tornado (3)
- 4. Thulted Condition Weight c (Service Level D) Thermal (1)
Dynamic riuid Loads (2)
SSE Inertia SSE Seismic Movements Pipe Rupture Loads NOTES;
- 1. Thermal conditions (including ambient tempetature) to be combined to provide maximum load combinations.
- 2. Dynamic riuid Loads due to safety / relief valve thrust, steam hammer, and water hammer.
- 3. Wind and tornado loads are not combined with earthquake loading.
DRAFT 7-35 July 25, 1992
______.________j1
._ -- -- ._ _ -. . . - . . . - ~ _ . . _ - - .. __
SYSTEM 80+* DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE 7.1.8 POSTULATED PIPE BREAKS 7.1.8.1 Classification ,
7.1.8.1.1 High Energy High energy piping systems are those systems or portions of systems that are maintained pressurized at either temperatures in excess of 200*F or at pressures exceeding 275 psig during any of the following normal plant operating modes. For s'ystems containing process fluids other than water, the atmospheric boiling temperature may be applied in place of the 200'F criterion.
- Reactor Startup
- Hot Standby
+ Operation at any Power Level
- Reactor Cooldown to Cold Shutdown Exceptions:
A. Non-liquid piping systems (air, gas, steam) with a maximum pressure less than or equal to 275 psig are not considered high energy regardless of the temperature.
B. Piping which operates at pressures and/or temperatures meeting high energy requirements is not considered high energy if the total time spent in operation at high energy conditions is less that either of the following:
- 1. One percent. of the normal operating lifespan of the plant, or
- 2. Two percent of the time period required to accomplish its system design function.
C. Piping of one-inch nominal pipe size and less is not considered "high energy."
7.1.8.1.2 Moderate Energy
~ Moderate energy piping systems are those systems or portions of systems, that during any of the normal plant operating modes are maintained pressurized at a maximum temperature of 200*F or less and a maximum pressure of 275 psig or less including all piping excluded from high energy.
Exceptions:
A. Open-ended vents and drains are not considered moderate energy.
l DRAFT 7-36 July 25, 1992 l
l t
SYSTEN 80+* DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE B. Piping of one-inch nominal pipe size and less is not considered moderate energy.
7.1.8.2 Postulated Ruoture Locationa 7.1.8.2.1 Break Locations in ASME Class 1 Piping Runs Breaks, in accordance with Section 7.1.8.2.5, shall be postulated to occur at the following locations in ASME Class 1 piping:
A. The terminal ends of the pressurized portions of the run.
B. At intermediate locations selected by either one of the following methods:
- 1. At each location of potential.high stress or fatigue, such as pipe fittings (elbow, tees, reducers, etc.),
valves, flanges, and welded attachments / or
- 2. At all intermediate locations between terminal ends -
where the following stress or fatigue limits are exceeded:
- TP J maximum stress _ range, S, between any two load sets (including the zero load set) calculated by Eq. (10) in Subarticle NB-3653, ASME Code,Section III, exceeds 2.4S, and the stress ranges calculated by both Eq. (12) and Eq. (13) in - Subarticle NB-3653, ASME Code,Section III, exceeds 2.4 S,.
- U exceeds 0.1.
Where: S. = allowable design stress-intensity value, as defined in Subarticle NB-3600, ASME Code,Section III.
U a the cumulative usage factor- .as ,
calculated in accordance with Subarticia NB-3600, ASME Code,Section III.-
7.1.8.2.2 Break Locations in ASME Class.2 and 3 Piping Runs Breaks, _in accordance with Section 7.1.8.2.5 shall be postulated to occur at the following locations in ASME Class 2 and 3 piping:
A. The terminal ends of the pressurized portions of the run.
DRAFT 7-37 Juiy 25, 1992-
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE B. At intermediate locations selected by either one of the following methods:
- 1. At each location of potential high stress or fatigue, such as pipe fittings (elbows, tees, reducers, etc.),
valves, flanges, and welded attachmento; or
- 2. Where the piping contains no fittings, welded attachments, or valves, at one location at each extreme of the piping run adjacent to the protective structure, or
- 3. At all locations where the stress, S, exceeds 0.8 x (X + Y). ;
Where, as defined in ASME Code, Subartic1G NC-3650, S = stresses under the cor.bination of loadings associated with the normal and upset plant condition loadings and an OBE event, as calculated from the sum of Eq. (9) and (10).
X = equation (9) Service Level a allowable stress.
Y = equation (10) allowable stress.
7.1.8.2.3 Break Locations in Non-Safety Related Piping Runs For non-safety class piping which is not seismically analyzed, leakage cracks are postulated at axial locations such that they produce the most severe environmental effects.
7.1.8.2.4 Break Locations In Piping Runs With Multiple ASME Code Piping Classes Breaks, in accordance with Section 7.1.8.2.5 shall be postulated to occur at the following locations:
A. The terminal ends of thb pressurized portions of the run.
B. At intermediate locations selected by either one of the following methods:
- 1. At each location of potential high stress or fatigue, such as pipe fittings, valves, flanges, and welded attachments; or
- 2. At all intermediate locations between terminal ends where the stress and fatigue limits of Sections 7.1.8.2.1.D.2, or 7.1.8.2.2.B.2, are exceeded.
DRAFT 7-38 July 25, 1992
. ~ - - .
. _ _ _ _ _ -..- _ _ _ ~ _ - _ _ - _ _ _ - . -
SYSTEM 80+* DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE 7.1.8.2.5 Break Locations Both circumferential and longitudinal breaks are postulated to occur, but not simultaneously, in all high-energy piping systems at the locations specified in Sections 7.1.8.2.1 through 7.1. 8.,2. 4 except as follows:
A. Circumferential breaks are not postulated in piping runs of a nominal diameter equal to or less than 1 inch.
B. Longitudinal breaks are not postultMd in piping runs of a nominal diameter less than 4 inchee C. Longitudinal breaks are not postulated at terminal ands. .
D. Only one type of break is postulated at locations where, from a detailed stress analysis, such as finite-element analysis, the state of stress can be used to identify the most probable type. If the primary plus secondary stress in the axial direction is found to be at least 1.5 times that in the circumferential direction for the most severe loading combination association with Level A and Level B service limits, then only a circumferential break is postulated. Conversely, if the primary plus secondary stress in the circumferential direction is found to be at least 1.5 times that in the axial direction for the most severe loading combination associated with Level A and Level B service limits, then only a longitudinal break is postulated.
E. Circumferential and longitudinal breaks are not postulated at locations where the requirements of Section 7.1.8.2.7 are satisfied.
F. Circumferential and longitudinal breaks are not postulated at locations where the criterion in Section 7.1. 8. 2. 6. 2 is used.
7.1.8.2.6 Crack Locations 7.1.8.2.6.1 Through-Wall Cracks Through-wall cracks are postulated in all high-energy and moderate-energy piping systems having a nominal diameter greater than 1 inch at the locations specified in Sections 7.1.8.2.1 through 7.1.8.2.4, except that through-wall cracks are not postulated at locations where: ,
A. For Class 1 piping, the calculated value of S, as defined in Section 7.1.8.2.1, is less than 1.2 S,.
DRAFT 7-39 July 25, 1992 i
i
SYSTEN 80+" DESIGN CERTIFICATION I DISTRICUTION SYSTEMS DESIGN GUIDE B. For Class 2 and Class 3 piping, the calculated values l of S as defined in Section 7.1.8.2.2 is less than 0.4 x (X + Y).
C. The requirements of Section 7.1.8.2.7 are satisfied.
D. The criterion in Section 7.1.8.2.6.2 is used.
7.1.8.2.6.2 Leakage Cracks A leakage crack is postulated in place of a circumferential break, oJ longitudinal break, or through-wall crack, if justified by an analysis performed on the pipeline in accordance with the requirements of Section 7.1.9.
For moderate-energy fluid systems in areas other than containment penetrations, leakage cracks are postulated at axial and circumferential locations that recult in the most severe environmental consequences. Where a break in a high-energy fluid system is postulated which re.aults in more limiting environmental conditions, the leakage crack in the moderate-energy fluid system is not postulated.
Leakage cracks, instead of breaks, are postulated in the piping of fluid systems that qualify as high-energy fluid systems for short operational periods of time but that qualify as morierate-energy fluid systems for the major operational period.
7.1.8.2.7 Piping Near Containment Isolation Valves Ruptures are not postulated between the containment wall and the inboard or outboard isolation valves in piping, which is designed in accordance with the rules of the ASME Code,Section III, and which meets the following additional requirements:
A. The limits for postulating intermediate rupture locatio.as, as specified in Section 7.1.8.2.1.for Class 1 piping and 7.1.0.2.2 for Class 2 and 3 piping, are not exceeded in that portion of piping.
B. Following a postulated pipe break of high-energy piping beyond either isolation valve, the stresses in the piping from the containment wall, to and including the length of the isolation valve, are maintained within Level C Service Limits as specified in the ASME Code,Section III.
C. The design and inservice inspection requirements, as specified in the USNRC Branch Technical Position, MEB 3-1 (CES SAR-DC, Section 3.6, Reference 4), are satisfied.
D. The containment isolation valves are appropriately qualified to assure that cperability and leak tightness DRAFT 7-40 July 25, 1992
._ . . . _ _ ~ _ .. - _- - - - .- - . - _ _ _ -
SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE are maintained when subjected to any combination of loadings, which could be transmitted to the valves from postulated pipe breaks beyond the valves.
E. For moderate-energy piping, the stresses calculated by the sum of equations (9) and (10) in ASME B&PV Code,Section III, NC-3653, do not exceed 3.4 times the sum of the i
stress limits given in DC-3653.
7.1.d.3 Postulated Ruo_t,ure Confiourations 7.1.8.3.1 Break Configurations 1
Where break locations are postulated at fittings without the
- benefit of a detailed stress calculation, breaks should be assumed
' to occur at each pipe-to-fitting weld. If detailed stress analyses or tests are performed, the maximum stressed location in the
! fittings may be selected as the break location. ,
Circumferential and longitudinal breaks should be postu'.ated in i fluid system piping and branch runs as specified in Saction i 7.1.8.2.5.
7.1.8.3.2 Crack Configurations
- Leakage cracks should ' be postulated at t. hose axial locations specified in Section 7.1.8.2.6.
For high-energy piping, leakage cracks should be postulated in those locations that result in the most severe environmental consequences. The flow from the crack should be assumed to wet all unprotected components within the compartment with consequent flooding in the compartment and communicat.ing compartments.
Flooding effects should be determined on the basis of a conservatively estimated time period required to effect enrrective actions, f
7.1.8.4 Pipe Ruoture Loads This section applies to all high-energy piping other than that whose dynamic effects due to pipe breaks are eliminated from the design basis by leak-before-break (LBB) evaluation.
A. Circumferential Breaks Circumferential breaks are assumed to result in pipe severance and separation amounting to at least a one-diameter lateral displacement of the ruptured piping sections, unless physically limited by piping restraints, structural members, or piping stiffness. The dynamic force of the jet discharge at the break location is based on the effective cross-sectional flow area of the pipe and DRAFT 7-41 July 25, 1992
SYSTEN 80+* DESIGN CERTIFICATION DISTRIEUTION SYSTEMS DESIGN GUIDE on a calculated fluid pressure as modified by an analytically determined thrust coefficient. Limited pipe displacement at the break locations, line restriction flow limiters, positive pump controlled flow, and the absence of energy reservoirs are taken into account, as applicable, in the reduction of the jet. discharge. Pipe whip is assumed to occur in the plane defined by the piping geometry and configuration, and to cause -pipe ,
movement in the direction of the jet reaction.
B. Dynamic-Force of the Fluid Jet Discharge 1 The dynamic force che fluid-jet discharge is based on a circular break area equal to the cross-sectional flow area of the pipe at the break location and on a calculated fluid pressure modified by an e.nalytically determined thrust coefficient, as determined for a circumferential break at the same location. Line restrictions, flow i limiters, positive pump-controlled flow, and the absence i of energy- reservoirs _ are -taken into account, as applicable, in the reduction of Pt discharge.
Piping movement is assumed to occur in the direction of the jet reaction, unless limited by structural membera, piping restraints, or piping stiffness.
C. Pipe Blowdown Force and Wave Force The fluid thrust forces that result from either postulated circumferential or -longitudinal breaks, are calculated using a simplified one-step forcing function methodology.
Thia methodology is based on the simplified methods ,
described in ANSI /ANS 58.2, ." Design Basis for' Protection of Light Water Nuclear Power Plants Against _the Effects of ,
Postulated Pipe Rupture". See CESGAR-DC, Section 3.6, References 5 and 6.
When the simplified method discussed above leads to impractical protective measures, then a more detailed computer solution which more accurately reflects the postulated pipe rupture event is used. The computer solution is based on the NRC's computer program developed for calculating two-phase blowdown forces. See CESSAR-DC, Section 3.6, Reference 7 D. Evaluation of Jet Impingement Effects Jet impingement l force calculations are performed only if structures or components are located near postulated-high~
energy line breaks and it cannot be demonstrated that
. failure of the structure or component will-not adversely affect safe shutdown capability.
DRAFT 7-42 July 25, 1992
SYSTEM 80'" DESIGN CERTIF; CATION DISTRICUTION SYSTEMS DESIGN GUIDE l l
E. Longitudinal Breaks A longitudinal break results in an axial split without severance. The split should be assumed to be orientated at any poinc of highest stress as justified by detailed stress analysis. For the purpose of design, the
, longitudinal break should be assumed to be circular or elliptical (2D x 1/2D) in shape, with an area equal to the largest piping cross-sectional flow area at the point of the break and have a discht.rge coefficient of 1.0. Any other values used for the area, diameter and discharge coef ficient associated with a longitudinal break should be !
verified by test data which defines the limiting break geometry. ;
7.1.8.5 Pipe Ruoture Analysis 7.1.8.5.1 Dynamic Analysis of Pipe Whip Pipe whio restraints usually provide clearance for thermal expansior during normal operation. If a break occurs, the restraints or anchors nearest the break are designed to prevent unlimited movement at 's point of break (pipe whip).
The dynamic nature of the thrust load is considered. In the absence of analytical justification, a dynamic load factor of 2.0 is applied in determining restraint loading. (Elastic-plastic) pipe and whip restraint material properties may be considered, as applicable. The effect of rapid strain rate of taaterial properties is considered. A 10 percent increase in yield strength is used to account for strain rate effects.
In general, the loadings that result from a break in piping are determined using either a dynamic blowdown or a conservative r,tatic blowdown analysis. The method for analyzing tha interaction effects of a whipping pipe with a restraint is one of the following: (1) Equivalent Static Method, (2) Lumped Parameter Method, or (3) the Energy Balance Method.
In cases where the time history or energy balance method is not used, a conservative static analysis model should be used.
The lumped parameter method is carried out'by utilizing a lumped mass model. Lumped mass points are interconnected by springs to take into account inertia and stiffness properties of the system.
A dynamic forcing function or equivalent static loads may be applied at each postulated break location with unacceptable pipe whip interactions. A nonlinear elastic-plastic analysis of the piping-restraint system is used.
The energy balance method is based on the principle of conservation of energy. The kinetic energy of *.he pipe generated during the DRAFT 7-43 July 25, 1997
SYSTEM 80+5 DESIGN CERTIFICATION CISTRICUTION SYSTEMS DESIGN GUIDE
't first quarter cycle of movement is assumed to be converted into equivalent strain-energy, which is distributed to the pipe or the whip restraint.
7.1.8.5.2 Dynamic Analysis of Unrestricted Pipes The impact velocity and kinetic energy of unrestricted pipes is calculated on the basis of the assumption that the segments at each side of the break act as rigid plastic cantilever beams subject to
- piecewise constant blowdown forces. The hinge location is fixed either at the nearest restraint er at a point determined by the requirement that the shear at an interior plastic hinge is zero.
The kinetic energy of an accelerating cantilever segment is equal to the difference between the work done by the blowdown force and that done on the plastic hinge. The impact velocity V: is found l I' rom the expression for the kinetic energy:
AT=fMy Vj (Eqn. 7.1-9)
Where My is the mass of the single degree of freedom dynamic model of the cantilever. The impacting mass is assumed equal to M y.
7.1.9 LEAK-BEFORE-BREAK 7.1.9.1 Depion of Pipino Evaluated For Leak-Before-Break The approach being taken toward design certification of System 80+
is to include leak -before-break (LBB) considerations in the piping design. One aspect of the LBB evaluation oursued for each selected piping system is performance of a preliminary LBB evaluation prior to and independent of pipe routing. This evaluation is used to provide the piping designer with LBB acceptance criteria, in terms of a range of materials, pipe sizes, and NOP and maximum design loads for all locations in the pipe. If the acceptance criteria is met, an acceptable result of the LEB evaluation of the final design is assured. The range of piping parameters developed by this preliminary evaluat. ion forms a " window" of acceptance criteria which the piping designer can utilize to route, design and support the piping system.
For the System 80+ design, the following five piping systems inside containment will be designed to the requirements of Section 7.1.9.2 to assure leak-before-break:
+ Main Coolant Loop (42-inen ID hot leg and 30-inch ID cold leg)
- Surge Line (12-inch diameter) -
DRAFT 7-44 July 25, 1992
SYSTEM 80+* DESIGN CERTIFICATION DISTR 2BUTION SYSTEMS DESIGN GUIDE
- Shutdown Cooling Line (16-inch diameter portion)
- Direct Vessel Injection (10-inch diameter portion)
- Main Steam Line (28-inch ID portion) 7.1.9.2 Pipine Desion Recuirements The piping design requirements for assuring that LBB is mot are given in Table 7.1.9-1 below:
TABLE 7.1.9-1 System 80+ Pipino Desion Requirements For LDB NOP Plus Max Pipe Weld Pipina System Desion ;oad Material Material Main Coolant Loop (Hot Leg) < >
Main Coolant Loop (Cold Leg) < >
Surge Iine (12") < (LATER) >
Shutdow.i Cooling Line (16") < >
Direct Vessel Injection (10") < >
Main Steam Line (28" ID) < >
The requirements of Table 7.1.9-1 are established by LBB evaluations using the methodology described in Appendix 7A. In addition to the requirements of Table 7.1.9-1, the five piping systems listed above must meet the LBB applicability criteria outlined in Appendix 7A, Section 1.2.1. NOP and maximum design loads are defined in I.ppendix 7A, Section 1.1.4. Appendix 7A also discusses design philosophy and of fers design guidelines for piping systems evaluated for LBB.
7.1.9.3 Pipino Desion Procedure The designer shall route, design and analyze the piping evaluated for LBB in accordance with the ASME Boiler and Pressure Vessel Code, considering the LBB requirements given above and utilizing guideline ls herein. As-calculated piping loads should be compared to the " window" of acceptance criteria in Table 7.1.9-1 established by the LBB evaluations. If the acceptance criteria are met, demonstration of LBB is assured. If the acceptance criteria are not met, tne au-calculated loads based on the actual routing should be evaluated for LBB using the finite element analysis methodology described in Appendix 7A, Section 1.3.4. If this LBB evaluation does not assure that LBB is met, an iterative process of generating revised LBB acceptance criteria for a re-sized pipe and redesigning the piping system should be pursued.
DRAFT 7-45 July 25, 1992
SYSTEM 80+5 DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 7.1.10 SMALL-BORE PIPING To simplify the procedure for the design of small-bore piping, two-inch nominal pipe size (NPS) and smaller, the procedure provided in HCIG-14, " Procedure for Seismic Evaluation and Design of Small Bore .
Piping" may be used in lieu of the more rigorous analysis as detailed in Section 7.1.4.
7.1.11 TUBING 7.1.11.1 General Process and instrumentation tubing is shown to be acceptable based on meeting the applicable support criteria within this section.
These criteria only applies to safety-related tubing / they serve as guidelines for non-safety related tubing which is not analyzed'and can be field routed (see Section 6.2.11.2.5).
Tubing is supported in two ways, as free tube spans and tube track supports. The criteria for each support mechanism are described in the following sections.
I 7.1.11.2 Free Tube Spans The following requirements apply to tubing that is supported as free tube spans (not in tube tracks) :
A. The minimum spacing between tube supports (L) should be two (2) feet unless the supports are used to support an in-line component in which case a tube support should be located adjacent to the component (on each side).
B. The maximum spacing between supports should be as indicated in Table 7.1.11-1.
C. If heat tracing or insulation is required, span lengths, l support designs, and tube details could require amendment.
l D. All reservoirs, valves, and other in-line components should be independently supported, E. Tube support lc9ations should be located accordingly if there is a change in direction or fitting in the span (see l
- Table 7.1.11-1).
F. When tees are used in tube routing, tube supports should be arranged as shcwn below.
DRAFT 7-46 July 25, 1992
SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTZMS DESIGH GUIDE n
A+B+C$L (L f rom Table 7.1.11-1)
Ai "
r , s
' \
4 b l l
= C N
G. In addition to the requirements listed above, supports for 1" tubing should be arranged as shown below:
L from Table 7.1.11-1 as b>
=
s . .___ ,
b ' ' -
7 ,, g 7" O
- MAX
=
V U l l DRAFT 7-47 July 25, 1992
8 l i SYSTEN 80+" DESIGN CERTIFICATION !
f DISTRICUTION SYSTEMS DESIGN GUI.QE l i
4
! TABLE 7.1.11-1
! Maximum Free Tube Sean Lenoths (L) i l Tube Straight- Change in Straight Change in ;
! Size Span Direction Tube With Direction Fitting and Fitting l
1/4" 6'-0" 4' - 6" 5' - 6" 4' -
0" ,
l 3/8" 8' - 0" 6'-0" 7' - - 6" 5' -
-6"
! 1/2" 8'-0" 6' - 0" 7' -
6" 5' - 6" r
5/8" 8' - 0" 6' - 0" 7' -
6" 5' -
6" :
3/4" 8' - 0" 6' - 0" 7' -
6" 5' ~ 6" 1" 8'-0" 6'-0" 7' -
6" -5' -
6" a
a Table 7.1.11-1 Notes:
l
- 1. The maximum allowable -internal _ design pressure is 2950 psig. *
- 2. Tube span lengths should be - amended' accordingly if insulation is required.
- 3. - The tube span before and after the span containing the change in direction should be. limited-to the same length as the span including the change in direction.
l l 4. The allowable spans for copper tubing should be one-half ,
j of the values tabulated.
l 7.1.11.3 Track Sitor,orted Tubec ,
The following requirements' apply to tubing routed ~in tube' tracks.
Sample lines should:not be installed- in- tube tracks t unless ' the .
process fluid temperature is less than 150*F.
Tube track should not be modified : by cutting or bending. Tube-( track should:be connected using standard-components.
t
'i DRAFT. 7-48 July 25, _ 1992
, w,*--=w+r w *we #**"-r w--- , ~5 -+ ,, w v , w +--w-~v e -w-wve-, van *- e- wm e + " b mew w + w~ v --6 e v- v"w-y-+e>vraw=-t+-two-=% , e y- e--*'**~tyt=t- T ' * - ' ' '-
SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE 7.1.11.3.1 Uninsulated Applications The following criteria apply to uninsulated tubing routed in tracks:
A. The maximum number of tubes per track should be four (4) for 1/4", 3/8", and 1/2" tubing. Tubes larger than 1/2" should be supported per Section 7.1.11.2.
B. The tubing should be attached te the tube track at a minimum of 2'-0" and a maximum of 3'-0" spacing.
C. The maximum span between track supports should be 8 ' -0 "
- for a straight span and 6'-0" if a change in direction occurs in the span. The maximum span length for spans adjacent to spans containing a er ige in direction is 6'-
0". ,
D. Tube track should not extend / overhang past the last track support by more than l'-0" .
E. Reservoirs, valves, or other in-line components should be independently supported.
F. When tees are used in the routing of tube track, track supports should be arranged as shown below:
a A + B + C 5 6'-0" A i !
A i r , s 3 6 i __
B V
l l l m C y -
--as DRAFT 7-49 July 25, 1992
_ ._ __ _ __ _ _ ~. . _ - - _ _ . _ . .
SYSTEM 80+5 DESIGN CERTIFICATION DISTF.ICUTION SYSTEMS DESIGN GUIDE I
7.1.11.3.2 Insulated and Heat Traced Applications l
The fallowing criteria apply for insulated and heat-traced tubing.
Other constraints could also apply based on the specific application.
A. Tne maximum number of tubes per track Jhould be two (2) for 1/4", 3/8", and 1/2" tubing.
B. Insulation and heat tracing of 5/8", 3/4", or 1" tubing may require additional analysia.
C. No more than two (2) heat trace cables should be allowed per track.
D. Insulation should be fiberglass, no tinicker than 1-1/2" .
The insulation should surround the tube track and have an inside diameter of 3" for L2x2 angle and C2x1 channel track, and 3-1/2" inside diameter for C4x1 channel track.
E. Tubing should be attached to the tube track at a minimum of 2'<0" and a maximum of 3'-0" spacing.
F. Reservoirs, valves, or other in-line components should be independently supported.
7.1.11.4 Suecort and Mountina Requirements Tubing that is routed in two or more Seismic Category I structures (i.e., Reactor Building, Containment, Main Steam Valve House, Nuclear Annex, Diesel Generator Building) should be verified to have sufficient flexibility tc allow for differential building displacements, i Non-safety related manifold valves, solenoid valves, cnd instruments located over or near safety-r31ated equipment or components should be supported using the criteria in this section, unless justified by analysis. This will prevent any damage, degracation, or liiterference with the performance of equipmont required for safety functions.
7.2 HVAC DUCTWORK AND SUPPORT / RESTRAINTS 7.2.1 GENERAL HVAC ductwork shall be designed and supported to withstand dead weight (DW) and seismic loading, as applicable. The design and analysis guidelines herein apply to the HVAC supports / restraints (S/Rs) to maintain S/R stresses within allowables and limit ductwork deflections to maximum deflaction (b) critaria.
Limiting ductwork displacements to b allowables precludes
, DRAFT 7-50 July 25, 1992 ,
SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS DESIGN GUIDE rigorous analysis of the sheet metal ductwork to ensure its
, integrity.
HVAC ductwork S/R systems shall be designed in accordance with American Institute of Steel Construction (AISC) standards (ANSI /AISC N690 for safety-related systems, Manual of! Stool Construction for non-safety related systems) . Essential safety-related ductwork constructed of pipe should be designed to ASME Class 2 standards, or equivalent.
7.2.2 DESIGN CONSIDERATIONS 7.2.2.1 Gravity Dead weight (DW) loads include the weight of the ductwork itself, in-line components (e.g., dampers), externally mounted components, insulation, plus the weight of the S/R or stiffeners. Other DW loads such as ice and snow are included where applicable. DW loads are considered for both seismic and non-seismic S/Rs.
7.2.2.2 Seismic 7.2.2.2.1 Safety-Related Ductwork Seismic S/Rs shall be used for all HVAC ductwork required to perform a safety function. Seismic load determination is discussed in Section 7.2.4.
The OBE and SSE should be considered separately with the OBE loads used for the Level B load combination and the SSE loads used for Levels C and D. Both horizontal and the vertical components of the seismic excitation should be applied simultaneously in the direction that will produce worst-case stresses and deflections.
7.2.2.2.2 Overlap Regions In areas where non-safety related ductwork p1tsses over or near safety-related equipment or components, the support / restraint and duct system should be designed so that it can maintain its structural integrity. This will prevent any damage, degradation, or interference with the performance of equipment required for safety functions.
In lieu of designing the entire ductwork system to withstand a seismic event, those portions of the duct passing over safety-related equipment or components may be isolated from the remaining duct by flexible duct connections and/or walls and supported seismically.
DRAFT 7-51 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIDUTION SYSTEMS DESIGN GUIDE 7.2.2.3 Thermal Expansjo_n, n
- Thermal expansion loads are negligible and are not considered.
7.2.2.e Internal Pressure Internal pressure loads are negligible and are not considered for the duct S/R system.
7.2.2.5 External Pressure Differential.
Dynamic external pressure differential (EPD) loads resulting from postulated pipe breaks should be considered for safety-related ductwork or ductwork whose failure could damage, degrade, or interfere with the performance of safety-related equiprint. This condition will normally be precluded by ductwork routing away from the affected area.
7.2.3 DESIGN LOAD COMBINATIONS The loading to be considered for the S/R system for the various Service Levels are as follows:
Service Level Load Combination A (Normal) DW B (Upset) DW + OBE C (Emergency) DW + SSE D (Faulted) DW + SSE + EPD 7.2.4 ANALYSIS AND ACCEPTANCE CRITERIA 7.2.4.1 General The general analytic / design procedure which should be used to design HVAC S/R systems is as follows:
A. Determine S/R locations and types using the guidelines given in Section 6.3.5.
B. Determine the response of the S/R system. Two methods of resporise determination may be employed.
( 1. Static Coefficient Method
- 2. Dynamic Analy is Method DRAFT 7-52 July 25, 1992 l
.. l
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE Descriptions and usage guidelines for these two methods are given in Sections 7.2.4.3 and 7.2.4.4.
C. Calculate S/R loads.
D. Design supports / restraints.
Note: When determining the flexural design properties of rectangular duct, a reduced effective width should be utilized where applicable. Section 01.9.2.2 and Appendix QC of ANSI /AISC N690 provide guidelines for computing effective width for safety-related ductwork, and Section 1.9.2.2 and Appendix C of the Manual of Steel Construction provide similar guidelines for non-safety related ductwork.
7.2.4.2 Damoina values A damping value of 5% may be used for both OBE and SSE for HVAC ductwork systems.
7.2.4.3 Jtatic Coefficient Method The static coefficient method is a simple conservative analysis method. No determination of natural frequency of the system is made. Instead, the system response is assumed to be the peak of the required response spectra. This response is then multiplied by a static coefficient of 1.5. This coefficient takes into account the effects of both multifrequency excitation and multimode response. Having determined the peak response accelerations for a given system, the S/R loadings may_be obtained by multiplying this acceleration by a factor of 1.5 and the participating mass.
This method of response determination results in very conservative S/P loads for the Upset, Faulted, and Emergency conditions. These loads should be safely sustained by the S/R and the structure to which the S/R is attached.
7.2.4.3.1 Static Coefficient Method Calculation The S/R loadings are calculated by the Static Coefficient Method as follows:
A. Determine Participating Load To establish the participating load (PL), all ductwork, and the S/R system should be modeled as a series of simple beams between S/Rs providing similar directions of restraint. The PL should include the weights of all ductwork and S/Rs included in the segment of ductwork being considered. Weight of other S/Rs, however, may be neglected.
DRAFT 7-53 July 25, 1992 i
L.
SYSTEM 80+* DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE B. Determine Normal Load 1
The normal load (NL) is the same as the PL when considering the vertical direction only. When determining loading in any other direction, the NL is equal to zero.
C. Determine Upset Load The upset load (UL) is determined by:
UL=NL+(PLxS ,) (Eqn . 7.2-1)
- Where: So,g = OBE Seismic Coefficient OBE = Operating Basis Earthquake loading, represented by:
OBE=PLxS x, (Eqn. 7.2-2) i D. Emergency Load i
The emergency load (EL) may be determined by:
EL=#Lt ( PLxS,,,) (Eqn . 7.2-3)
Where: S se = TSE Seismic Coefficient SSE = Safe Shutdown Earthquake loading, represented by:
4 SSE=PLxS,,, (Eqn. 7.2-4)
E. Faulted Load The faulted load (FL) may be determined by:
FL=NLt ( PLxS,,y) (Eqn. 7.2-5)
The values for S are the g_ak responses for the different areas and elevations from the " Acceleration Response Spectra curves", multiplied by 1.5 as indicated in Section 7.2.4.3.
J DRAFT 7-54 July 25, 1992
t SYSTEM 800" DESIGN CERTIFICATION 4
DISTRIBUTION SYSTEMS DESIGN GUIDE
. The maximum deflection ( A.. . ) , that can be sustained so that the duct function is not impaired should be determined by analysis.
7.2.4.4 Dynamic Analysis Method For the dynamic analysis methrd the ductwork and S/R system is modelled to best represent its mass distribution and stiffness characteristics. This model is then analyzed to determine if it is rigid or flexible. All systems having natural frequencies greater than cutoff frequency for the ZPA are considered rigid, where the !
l
- ZPA (zero period acceleration) is the accaleration level of the high frequency, non-amplified portion of the response spectrum.
For rigid systems, S/R loadings for the various operating
- conditions may be determined by multiplying the maximum floor ,
- acceleration (the ZPA of the floor response spectrum), and the !
i participating masses. This is an equivalent static analysis, i
Flexible systems (i.e., systems having natural frequencies less than the cutoff frequency for the ZPA), may be analyzec using response spectrum model analysis techniques or time history analysis techniques. H0 wever, in lieu of implementing these
- analysis techniques, it is desirable to use the simpler equivalent i static analysis technique. Therefore, systems having natural j~ frequencies less than the cutoff frequency for the ZPA may be redesigned such that they are rigid and the equivalent static analysis is justified. This redesign implies an increase in system stiffness, a decrease in system mass, or a combination of both.
7.2.4.4.1 Dynamic Analysis Method Calculation In the dynamic analysis method the stiffness of the ductwork and the ctiffness of tae S/Rs in specified directions should be considered when evaluating-a " system" stiffness. If this system
' stiffness is such that a natural frequency is greater than the cutoff frequency for the ZPA, the duct-S/R system may be considered rigid and the maximum floor response acceleration may be used in calculating the seismic S/R loadings. This is the basic objective of the dynamic analysis method.
A. Calculate Participating Load When calculating the duct-S/R system natural frequency, an appropriate participating mass (or participating load, PL) should be considered. The mass should consist of the following:
- 1. Mass of the S/R being analyzed.
- 2. Mass of applicable length (s) of ductwork assuming the duct run is a series of simply supported beams between S/Rs providing the same direction of restraint.
i DRAFT 7-55 July 25, 1992
. SYSTEM 80+* DESIGN CERTIFICATION
, DISTRICUTION SYSTEMS DESIGN GUIDE
- 3. Mass (es) of other S/Rs within the _ applicable duct span. ;
- 4. Mass (es) of equipment.
B. The dynamic analysis method is applied to the two gegeralized categories of S/Rs as follows:
- 1. Lateral and vertical S/Rs in various combinations. '
- 2. Axial S/Rs.
C. Lateral and Vertical S/Rs Ihese two functional types of S/Rs may be considered in a single category for determining a 'ductwork flexural rigidity for both types of S/Rs.
- 1. Plan View i
t,. -
9,
= ~ W 2, w? sig 9z -
a
<, . 1 . ,,
'I s . .
N X
4 G .@ @ @ @
A, 3 I t , chl Ar, I,, Gh S/Rs 1, 3, and 5 are lateral-vertical S/Rs (x-y):
S/Rs 2 and 4 are vertical- S/Rs -(y)
- 2. Load Model Ch Ch !
s ,
- l l' j l l l l l' l i l
. r~ V~
~ ~
1
-G l ;
.D 6 3 & 6, D.
A, f Oz I
h DRAFT 7-56 July 25, 1992 [
'l i ,
. _ _ . .._m__.._.__ .. _ _ _.___.___ _ ._____ __._._.__ _____.__ _ __.
I SYSTEM 80+" DESIGN CERTIFICATION 2 DISTRICUTION SYSTEMS DESIGN GUIDE
]
i 4 3. Calculate Duct Stiffnesses (Assumes S/Rs as infinitely rigid)
.l For the simple beam models and loadings shown, the
- maximum 1 g lateral (' x' ) deflections are
- 4 5 x Ig "i tl (Eqn. 7. 2-6) _
A =
1m - 3 84 g i
k i 4 8 (Eqn . 7.2-7) j A ,**. _ 5 x "22 384- IsyE :
' l
. Where: b = Maximum duct deflection -(in) J (0 = Duct loading per unit length (Ibc/in) 1 = Duct length (in)
I = Duct section modulus (an')
E = Duct modulus of elasticity --(psi)- .
Note:-For loading distributions other than. that shown, appropriate expressions for A, should be developed.
K2m=
1 1 (lbs/ inch) (Eqn . 7.2-8) 1, K ,= Au 1 (lbs/!nch) (Eqn. 7.2-9) i
~
Where: Ko, = Duct stiffness (1bs/in).
- 4. Calculate the participating mass _ (participating load, PL) in the applicable direction acting;on-the S/R
-being analyzed.
PL,fg = P,fp"1 *+"* *+P,fg * (Egn. 7.2-10)
Where: P fa = S/R weight (1bs)
- Note that only S/R, is considered-as it falls within the half-span -(1/2) 2 being-considered for:S/R 2. In DRAFT 7-57 July 25, 1992
SYSTEN 80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN _ GUIDE- l l
general, only those S/Rs falling in the half-spans !
nearest the S/R being analyzed need to be e considered in- .the. participating mass (PL) l calculation. The effects - of - these S/Rs may be ;
shown t6 be negligible and not considered in the :
analysis. !
i
- 5. Calculate b ef. in the applicable direction due to a 1 g loading. This calculation may be performed by ;
simplified hand calculation methods or by computer. '
Not.e that for this example the applicable direction is in the 'x' direction.
- 6. Calculate the stiffness of tue S/R in the direction considered. j h
M i t.t K !
10uct- 2 Duct.
S/R
- K,j, =
8'*
(lbs/ inch) (Eqn. 7.2-11) [
Ms/a !
' X,,,, =
8 (Fo0!;/ direction)'
'7 Develop the -spring-mass model ^
and calculate 'the :
equivalent ' system' stiffness -
For the lateral-'and vertical: directions the' spring- l imass_model used is as follows:- !
8/8 (Eqn _ 7. 2-12)
N,. e !
- 9. ;
4 l
l DRAFT 7-58 July 25, 1992 t
, - . . - . .- . - . . - . - . - . - ..- . . - - -- . . -. . .- -.- .- _- - - . - ~.
l
- SYSTEM 80+" DESIGN CERTIFICATION 1
- DISTRICUTION SYSTEMS DESIGN GUIDE j Where: PL i n from Step 4 (1bs) j Ms.i = Total mass (ibm) l g = 38 6.4 in/sec' V I
I
! The equivaler2t stiffness is given by:
Y 1
)
= +- (Egn. 7 . 2 -3 "J )
! Km
- K1 ,, + Kg,, Ks/n
-OR-
- '"(lbs/ inch) (Eqn. 7.2-14) !
K,=
K1 _"'+Kg,, +Ksts ,
i
- 1. --
Note: As an alternate, a single span system model may be used.- Effective mass and spring rates of
' the S/Rs should be'used. The system. frequency
- of the actual spans on either side of the S/R I should be determined separately with the lower
! of the two controlling.- Typically, the longer span-of duct and/or the duct'with the lowest'
~
i
- section properties control. . Each S/R . is
- required to support a weight of duct equivalent
! - to the weight of the chosen span of duct.
I ,
The alternate single span spring-mass model would be l
, as follows:
i Mex = 78/A *
- 8/A (Egn. 7.2-15) 9 i
!. Where: g = 386.4 in/sec 8 4
1
- i l
4 4
i DRAFT 7 July 25,.1992-1 r',,. , - - , . ,. ,~- n -n - - , , , . . +.....a.. , . . . ,,,,,,-,..,-..,,--r. ,r,..., .,,-r a._,. ,n
... . .. - - . - - - . - . . . - . . . .- . = - - - . - . - - . . -- .. . . - -
-SYSTEN-80+" DESIGN CERTIFICATION i DISTRIEUTION SYSTEMS DESIGN GUIDE t
The equivalent stiffness is given by:
.1= 1 +
1 Km Ks/a,+Ksts Kweg
--og.
K= '*" *'* *'**
m Kmcc+K,,,, +K,,z (1bs/ inch) 1 Where:
"2 (Eqn. 7.2-16)
Km,e = O m
- P,pa + u l K,f, = (Eqn . 7.2-17)
Msta A
5 x "l' (Eqn . 7.2-18) m= 384 ImccE '
Both of these spring-mass models will produce frequencies lower than a complete system model.
- 8. Calculate the natural frequency of the system.
Km (Eqn. 7.2-19) fn"Y'=1 2x) Ne- e r
fn~ 'u 1 Irc8 (Eqn. 7.2-20) 2x) PLsta -
Where- fn,y, = System natural frequency (Hz) '
l 9. If fa,y, -is greater than the ZPA, the system is rigid. f
! and the appropriate seismic acceleration coefficient should~ be ~ chosen from thn '" Acceleration Response. ;
Spectra Curves" . Upset and Faulted condition: loadings -
are then calculate,d as outlined in Section 7.2.4.3.
DRAFT' 7-60 July 25, 1997 i
.. . , . -_ . . _.. _ . _ ~ . .
SYSTEM 80+* DESIGN CERTIFICATION DISTRIGUTION SYSTEMS DESIGN GUIDE The values for S in this case are the ZPA acceleration coefficients for the areas and elevations from the
" Acceleration Response Spectra Curves".
D. Axial S/Rs This functional type of S/R is considered in a separate category since an AE/L stiffness is being evaluated for the ductwork.
- 1. Plan View A,
i I, coil Aa , I, Qb w \ w
~
1 . s . --
\ /
f
- 6 6 % @ s
= q 7 .__. q - =j S/Rs 1 and 5 are vertical-lateral S/Rs (x-y)
S/Rs 2 and 4 are vertical S/Rs (y)
S/R 3 is an axial S/R (z)
- 2. Determine applicable lengths of ductwork and calculate ductwork stiffness. Axial direction stiffness is '
given by:
Kou,,=-- (Eqn. 7.2-21) a Where: A = Cross-sectional area (in )
E = Duct section modulus (psi)
L = Applicable length (in)
Note: If the duct area varies in length L, the average area (Aav) can be used, as shown Selow:
DA8LI (Egn. 7.2-22)
Ay= E , g DRAFT 7-61 July 25, 1992
. - m ._ _. _ _ . _ . _ . . _ _ . _ . . . . . _ _ . . ._ ___ _
SYSTEM 80+" DESIGN CERTIFICATION-DISTRIGUTION SYSTEMS DESIGN GUIDE )
Kw = %,E (1bs/ inch)'
A2"E X_=
2 (1bs/ inch)
- 3. Calculate participating mass (PL) -in the applicable direction _ acting on the S/R-being analyzed.
PLsta *Ps/a, * ( 01L1+ u a2 L ) + ( Ps/s,
- Ps/s + P,,,, + P,,z )
(Eqn. 7.2-23)
- Note that all S/Rs in the-applicable duct lengths-are considered in this example.
The- effects ~ of-these - Si Rs - may ' be shown to be negligible and not considered in the_ analysis.-
- 4. Calculate A ,,, in the applicable direction due to the .1 g leading. This calculation _may be performed-by simplified handLcalculation' methods or by computer.
Note that:-for this example the applJ. cable direction is in the 'z' direction.
- 5. Calculate stiffness of the 'S/R in the direction considered (z).
i N
tot 4 '
5 720uctchK2 Duct K
S/R ,
-1 ,.,,,,,,,,
l i
PL,,,, - !
K,,,, =
Ws/s ,
?
t DRAFT 7-62 July 25,_1992 [
..c , _ _ - , . , -. , ,__._,__u_ . - _ _ _ , , _ . _ . , , . , . _ __
~. . . - . _ _
SYSTEM 80+" DESIGN CERTIFICATION DISTRIriUTION SYSTEMS DESIGN GUIDE
- 6. Develop the spring-mass model and calculate the equivalent ' system' stiffness.
For the axial direction, the spring-mass model is as follows:
PLgia Meoe =
g 3
Where: PLsen from Step 3 (1bs) g = 386.4 in/sec' The equivalent stiffness is given by:
1, 1 .
1 Km K1 ,,+K2 ,, Kgia p
-OR-K= (K1* +K2*) K#'* (lbs/ inch) m K1 _+K2w+Kst r
- 7. Calculate the t.atural frequency of the system.
= 1
- En'Y' 2n) Me ,e 1 Kgw
[n a 2n) PLgja
- 8. If fn,y, is greater than the ZPA, the systent is rigid and the appropriate seismic acceleration coefficient should be chosen from the " Acceleration Response Spectra Curves" . Upset and Faulted condition loadings 4 are then calculated as outlined in Section 7.2.4.3.
The values for S in this case are the ZPA acceleration coefficients for the different areas and elevations from the ' Acceleration Response Spectra Curves".
DRAFT 7-63 July 25, 1992
l 1
l SYSTEN 80+" DESIGN CERTIFICATION-DISTRICUTION SYSTEMS DESIGN-GUIDE--
7.2.5 ALLOWABLE STRESS CRITERIA All HVAC S/R systems should be able to safely sustain stresses induced by the various loading _ conditions. .The criteria determining the allowable stresses _are established using conservative values in compliance with the- requirements of CESSAR-DC and ANSI /AISC N690. These values are provided-as a basis for evaluating _the required structural integrity of the support / restraints.
Stress levels for the various operating conditions shall be as follows: ,
Normal- Upset- ' Emergency- Faulted-Service Level A Service Level B Service Level C Service ~ Level D Basic Stress Basic Stress 1.6 x Basic 1.7 x Basic Allowables Allowableu Stress SL ess Allowables Allowables In addition to satisfying the-above stress _ limits, the S/R system should be oesigned tc safely transfer all' loadings to the ,
structure. Concrete expansion anchors shall meet the requirements o f ACI-3 4 9, " Code Requirements for Nuclear Safety Related Concrete Structurev'.
7.2.6 ALLOWABLE DEFLECTION CRITERIA No S/R deflection limitations other than those implied by the stress criteria given in Section 7.2.5 and any S/R system stiffness requirements are imposed.
7.3 CABLE TRAY / CONDUIT AND SUPPORT / RESTRAINTS 7.3.1 GENERAL Cable tray and conduit should.be analyzed in a similar manner as HVAC ductwork, designed and supported to withstand dead weight (DW) , ' and seismic loading, as applicable. The design and. analysis guidelines apply to the cable tray and conduit supports / restraints-(S/Rs) to maintain S/R stresses within allowables.
Cable tray and conduit S/R systems shall be designed in accordance with American Institute of Steel Construction (AISC) standards-(ANSI /AISC N690 .for safety-related systems, Manual- of Steel Construction for non-safety related systems)
DRAFT 7 July 2.5, 1992
SYSTEM 80+* DESIGN CERTIFICATION DISTRIBUTION SYSTEMS ' SIGN GUIDE 7.3.2 DESIGN CONSIDERATIONS 7.3.2.1 Gravity Dead weight (DW) loads include the weight of the cable tray or conduit itself, fittings, externally mounted components, cable tray covers, fireproofing, plus the weight of the S/R or stiff eners. DW loads are considered for both seismic and non-seismic S/Rs.
7.3.2.2 Se_1pmic 7.3.2.2.1 Safety-Related Cable Tray and Conduit Seismic S/Rs shall be used for all cable trayJ and conduit required to perform a safety function. Seismic S/Rs are discussed in Section 7.3.4.
The OBE and SSE should be considered separately with the OBE loads used for the Level B load combination and the SSE loads used for Levels C and D. Both horizontal and the vertical components of the seismic excitation should be applied simultaneously in the direction that will produce the worst-case stresses. .
7.3.2.2.2 Overlap Regions In areas where non-safety related cable tray / conduit passes vver or near safety-related equipment or componento, the support / restraint and cable tray / conduit system should be designed so that it can maintain its structural integrity. This will prevent any damage, degradation, or interference with the performance of equipment required *or safety functions.
In lieu of designing the entire cable tray / conduit system to
, withstand a seismic event, those portions of the cable tray / conduit passing over safety-related equipment or components may be isolated from the remainder of the system and supported seismically.
7.3.2.3 Thermal Exoansion c
Thermal expansion loads (T) are negligible and should not be considered.
DRAFT 7-65 July 25, 1992 I
1 i
SYSTEN 80+* DESIGN CERTIFICATION l
. DISTRICUTION SYSTEMS DESIGN GUIDE l i l
}
7.3.3 DESIGN LOAD COMBINATIONS The design loading to be considered for the S/R system for the various Service Levels are as follows:
Service Level Load Combination A (Normal) DW B (Upset) DW + OBE C (Emergency) DW + SSE D (Faulted) LW + SSE 7.3.4 ANALYSIS AND ACCEPTANCE CRITERIA
".3.4.1 General The general analytic / design procedure which should be used to design cable tray and conduit S/R systems is as follows:
A. Determine S/R locations and types . using . the guidelines given in Section 6.3.5.
B. Determine'the response of the S/R system. Two methods of response determination may-be employed.
- 1. Static Coefficient Method
- 2. Dynamic-Analysis Method Both the' s t a t.i. c coefficient method and the -dynamic analysis method of response determination can yield an j equivalent static approach.to the-seismic analysis of the l
S/R system. Descriptions and usage guidelines for these-two methods are given in Sections 7.3.4.3 and-7.3.4.4.-
, C. Calculate S/R loads.
D. Design supports / restraints.
' 7.3.4.2 Damoina values Damping values should be similar to HVAC ductwork systems .-- A damping value of 5% may be used for both the -OBE and SSE load j
! cases. '
l DRAFT 7-66 July 25, 1992 i
SYSTEM 80+" DESIGN CERTIFICATION DISTRIEUTION SYSTEMS DESIGN GUIDE 7.3.4.3 Static Coefficient Method The static coefficient method is a simple conservative analysis method. No determination of natural frequency of the system 13 made. Instead, the system response is assumed to be the peak of the required response spectra. This response is then multiplied by a static coefficient of 1.5. This coefficient takes into account the effects of both multifrequency excitation and multimode response. Having determined the peak response accelerations for a given system, the S/R loadings may be obtained by multiplying this acceleration by a factor of 1.5 and the participating mass.
This method of response determination results in very conservative S/R loads for the Upset, Faulted, and Emergency conditions. These loads should be safely sustained by the S/R and the structure to which the S/R is attachec.
7.3.4.3.1 Static Coefficient Method Calculation LATER 7.3.4.4 Dynamic Analysis Method For the dynamic analysis method the cable tray / conduit and S/R system is modeled to best represent its mass distribution and stiffness characteristics. This model is then analyzed to determine the system response.
7.3.4.4.1 Dynamic Analysis Method Calculation LATER 7.3.5 ALLOWABLE STRESS CRIT 2RIA All cable tray / conduit S/R systems should be able to safely sustain stresses induced by the various loading conditions. The criteria determining the allowable stresses are~ established using conservative values in compliance with the requirements of CESSAR-DC and ANSI /AISC N690. These values are provided as a basis for evaluating the required structural integrity of the support / restraints.
Stress levels for the various operating conditions shall be as J
follows:
Normal- Upset- Emergency- Faulted-Service Level A Service Level B Service Level C Service Level D Basic Stress Basic Stress 1.6 x Basic 1.7 x Basic Allowables Allowables Stress Stress Allowables Allowables l
DRAFT 7-67 July 25, 1992
l SYSTEN 80+" DESIGN CERTIFICATION DISTRIEUTION SYSTEMS DESIGN GUIDE 1
- In addition to satisf"ing the above noted stress limits, the S/R_-
- system should'be designed to safely transfer allLloadings to the u j
structure. _ Concrete expansion anchors shall meet the requirements !
of ACI-349, " Code F.equirements - for Nuclear' Safety Related Concrete
=
Structures". '
i
- 7.3.6 ALLOWABLE DEFLECTION CRITERIA ;
j- No S/R deflection limp.ations other than ' those - implied- by the-stress criteria given in Section 7.3.5 and any S/R system stiffness
- requirements are imposed.
f 7.4 EEFERENCES -
1
. 7.4.1 CESSAR Design Certification, System 80+ Standard Design,
, Amendment I.
1
'7.4.2 ASME 3 oiler and Pressure Vessel Code,Section III, Nuclear Power' Plant ~ Components,_. Class 1, 2, and 3, 1989' Edition.
7.4.3 ASME B31.1-1989 Edition, Power Piping.
- 7,4.4 ASME Code Case . N-411-1, " Alternate Damping . Values for
! Response-Spectra Analysis of Class'1,_2, and 3~ Piping, l Section III,-Division I".
i j
~
7.4.5 USNRC Regulatory Guide 1.92, " Combining Medal Responses and Spatial Components in Seismic Response Analysis",
l Revision 1, February 1976.
- 7.4.6 USNRC Regulatory Guide 1.76, " Design Basis Tornado for Nuclear Power Plants", April 1974.
7.4.7 Texas . Utilities Letter - TXX - 3423, " Comanche - Peak' Steam Station, Functional Capacity of-ASME Code Class 2 and 3
[ Stainless Steel Elbows".-
l l 7.4.8 NCIG-14, " Procedure for' Seismic Evaluation and Design of
' Small Bore Piping", EPRI-NP-6628, April-1990.
7.4.9 ANSI /AISC N690, _" Nuclear Facilities-Steel Safety-Related' Structures for Design Fabrication and Erection".
l i 7.4.10 MSS-SP-58, " Pipe Hangers and Jupports-Materials, ' Design
- and Manufacture".
I 7.4.11 USNRC Branch Technical Position, MEB 3-l' of Standard
- Review Plan 3.6.2 in NUREG-0800.
l
! . DRAFT 7-68 July 25, 1992
. - . .-. _ - . . - . - . - - - . - - . _ . - . - . - . - . - ~ . - . -
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. SYSTEM 80+" DESIGN CERTIFICATION DISTRIBUTION-' SYSTEMS' DESIGN GUIDE l
7.4.12 ANSI /ANS 58.2, " Design Basis for. Protection of Light Water 2 Nuclear Power Plants Against the . Effects .of Postulated
- Pipe Rupture".
7.4.13. AISC Manual of Steel Construction.-
i
! 7.4.14 ACI-349, " Code Requirements for Nuclear Safety Related j
Concrete Structures",
s
! 7.4.15 ASME Boiler and Vessel Code, Code Case N-318,." Procedure
' for Evaluation of the Design of Rectangular Cross-Section Attachments on Class 2-or 3 Piping".
. 7.4.16 ASME Boiler and Vessel Code, Code Case N-392, " Procedure i
for-Evaluation:of=the-Design of Hollow Circular Cross-
) Section Welded Attachments to Class 2 or 3 Piping,-Sectilon III, Division I".
}
i i .
i i
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i i
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DRAFT 7-69 ; July 25, 1992 4
5
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SYSTEN 80+" DESIGN' CERTIFICATION-DISTRICUTION SYSTEMS: DESIGN GUIDE APPENDIX 7A 1.0 LEAK-BEFORE-BREAK 1.1 - PLANT AND TiJI]?ING DESIGN CONDITIONS 1.1.1 PIPING DESIGN PARAMETERS The use of~ Leak-Before-Break (LBB) technology has, in the past,=
been limited to the avaluation of piping systems-already designed and constructed. The System . 80+ design certification approach makes it- possible .to- design certain piping systems such that elimination of the dynamic effects of postulated pipe breaks by LBB -
is assured at the design stage.
In piping design,; fluid system requirements normally drive ~ the selection of specific piping parameters._ For those piping systems chosen for.LBB evaluation, LBB considerations must be! integrated-into the process- of selecting those design parameters.
Specifically, the design parameters fo.r - which- :LBB .should be considered include pipe size- (cross-section), pipe _-and weld ,
materials, loads, and piping system thermal' flexibility..
The pipe and weld material should be chosen considering LBB requirements along-with' system,~ stress and fatigue requirements.
Within the limitations of the fluid- system and ASME Code requirements,-the designer should select pipe and weld materials which have good corrosion resistance, high yield'and high toughness characteristics.
Piping system thermal- flexibility 'is governed- by. the -stress requirements of the ASME: Code and~ the duty cycle of-loadings. _The piping system should be routed such that it is - sufficiently flexible to be able-to thermally deflect withoot-exceeding stress or fatigue limits.- - It should also meet criteria for all- ~1ead -
combinations associated with earthquakes (see, Sections 7.1'. 4 through 7.1.G).
Increased flexibility'of the piping-system results_in lower' pipe
-loads from thermal loadings.- Low normal 1 operation (NOP) loads are.
advantageous in the LBB' crack stability analyses provided thatflow NOP loads do not . result in a leakage crack liength that is too long.
A smaller NOP load .results in-a longer circumferential. crack length necessary to produce a ' crack with a detectable _ flow- rate. This longer crack leaves a weaker pipe cross section, which is subjected -
to load combinations in the-stability analyses. .This means that the pipe designer must also be mindful of the SSE-loading:if:the-pipeline under .consideratior. .is to- meet - LBB requirements.
Inclusion of. seismic supports'should be considered in the overall flexibility of the piping Esystem. A piping system that 'is made too
' DRAFT 7A-1 July 25, 1992
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SYSTEN 80+" DESIGN CERTIFICATION-DISTRICUTION SYSTEMS DPSIGN GUIDE
~
APPENDIX 7A flexible because of NOP considerations alone'could require too many seismic snubbers.
The approach in considering piping _ system- thermal ' . flexibility should be to route the pipe subject to the thermal loadin9s, other NOP loadings, seismic loadings and stress and fatigue limits.-
Revisions or 1. imitations to certain thermal modes of operation may need to be considered in order to satisfy- thermal flexibility requi re.r.ent s . Determination of-a leakage crack length for LBB should be mace on the basis of the NOP pipe loads generated or-may be conservatively calculated by applying operating pressure alone to the crack model (see Appendix 7A, Section 1.3.3).
1.1.2 LEAKAGE DETECTION SYSTEMS CESSAR-DC, Section 3.6.3.3.1 states the following:
A leak detection system is recommended by NRC Regulatory Guide 1.45 capable of detecting a leakage rate of.. 1.0 gpm...or less. . .from the primary : system. NURTG-1061, volume 3, " Evaluation _ of Potential- for -. Pipe Breaks",
recommends a safety margin of ten on the. leak-detection system. Diverse measurement means are provided, including water inventory monitoring, sump level and flow monitoring, and measurement of airborne radioactive particulates _ or gases.... Leak detection system requirerents to support the LBB analysis for main steam line piping are met by a combination of humidity detectors, condensation on the containment air coolers, radioactive' airborne activity sensors-and sump flow and level meters.
The various means of leak _ detection support, but may not be designed specifically to, the requirements of_the LBB evaluation.
NRC Regulatory Guide 1.45 requires a Leakage _ Detection System (LDS) capable of detecting a-1.0 gpm rate:cr less,. independent of_LBB requirements.- The LBB evaluation, however, depends on. these
" diverse measurement means", their diverse sensitivities and-accuracies, which constitute the LDS, in order to correlate a crack length to a ficw rate ten times the leak, detection capability.
Unless ctherwise justified, the - LBB evaluations _ of System. 80+
- piping systems should be based on a leak detection capability of .
1.0 gpm and a-safety margin of 10.
-1.1.3 CONSIDEhATION OF POTENTIAL 1FOR DEGRADATION _ SOURCES CESSAR-DC, Section-3.6.3.1, states the following:
Picing _ evaluated- for LBB is first shown . to meet the applicability requirement of NUREG-1061, Volume 3. The
-DRAFT 7A-2 July.25, 1992
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SYSTEM 80+* DESIGN CERTIFICATION DISTRIEUTION SYSTEMS DESIGN GUIDE APPENDIX 7A piping is designed to meet the require. ment te have a low susceptibility to failure from the effects of corrosion, water hammer or low- or high-cycle fatigue, or degradation or failure of the piping from indirect causes such as missiles or failure of nearby components.
In order to meet the commitment of CESSAR-DC, Section 3.6.3.1, the LBB evaluation must consider pipe and weld material selection, significant thermal modes of operation, the environment in which the piping is routed, and potential for water hammer within the particular fluid system, as each relates to the potential for degradation of the pipe (see NUREG-1061, volume 3, Section 5.1).
Consideration of LBB, in turn, should be integrated into the process of selecting materials (for corrosion resistance),
determining modes of operation (for reduction of loads from critical thermal transients), designing the piping system to preclude water hammer, and routing, where possible, to minimize the potential of failure of the pipe from indirect causes (see Sections 4.2.1.2. 4.2.1.3, 6. 2. 9 and 7.1. 2. 6) .
1.1.4 CONSIDERATION OF LOADING CONDITIONS Loads due to NOP (dead weight, pressure, and normal steady state thermal conditions) should be applied to the pipe section to calculate a crack length that will result in ten times the detectable leakage rato. As previously mentioned, a pressure-only load may be considered in this crack length determination in order to generate a maximum bounding case on leakage crack length. For smaller pipes, this could be too conservative, in which case a full set of NOP loads should be applied to determine crack length.
NOP loads, critical thermal transients (including loads due to thermal stratification, Sections 6. 2.10 and 7.1. 2. 8) , SSE loads, and normal operation dynamic transient loads (such as from rapid valve closure), combined in the same manner-as prescribed in the piping design specification for the ASME Code design report, should be considered in the stability analyses. The combination of the NOP load and the largest of the design loads (which will be referred to herein as the " maximum design" load) should be applied to the cracked pipe section in the stability analyses, along with the applicable load margin. Minimization of the above loads is, in j general, advantageous to the LBB evaluation and should be pursued l in the routing and design of .the selected piping system (see Appendix 7A, Section 1.1.1 for a further discussion with respect to LBB). In addition, overuse of dynamically activated snubbers to reduce piping response loads due to seismic and dynamic transient excitations should be avoided, or at least be balanced against the reduced reliability and maintainability that snubbers can cause in plant operations (see Sections 6.2.3 and 6.2.9) .
DRAFT 7A-3 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRIDUTION SYSTZMS DESIGN CUIDE APPENDIX 7A 1.2 CRITERIA 1.2.1 APPLICABILITY OF LBB CLSSAR-DC, Section 3.6.3.1, outlines the LBB- -applicability requirements for a piping system by committing' to the applicability requirements of NUREG-1061, Volume 3 (also see Appendix 7A, Section 1.1.3).
1.2.2 DETECTABLE LEAKAGE RATE REQUIREMENT ,
Per NUREG-1061, Volume 3, the detectable leakage rate. requirement of the leak detection system is 1.0 -gpm or less. The leakage crack -
to'be subjected to the crack stability analyses should-leak at a rate ten times the capability of the LDS. CESSAR-DC, Section 3.6.3.3, commi:s to these requirements ' of NUREG-1061, volume 3.
Unless otherwise justified, LBB evaluations should be based on.a leak detection capability of 1.0 gpm.
1.2.3 STABILITY ANALYSIS ACCEPTANCE CRITERIA CESSAR-DC, Section 3.6.3.9,. summarizes the stability analysis acceptance criteria as follows:
A. Cracks which are-assumed'to grow through the pipe wall leak significantly while remaining stable. The amount of leakage is detectable with a safety margin of at least a factor of 10.
B. Cracks of the length that leak at the rGte in A above can withstand normal operation pipe maximum design loads with
.a safety factor of at least 42.
C. Cracks twice.as'long as those addressed-inLB-above will remain stable when - subjected to normal operation plus-maximum design loads. -
NOP and maximum design loads are defined in Appendix'7A, Section 1.1.4.
1.3 ANALYSIS 1.3.1 DETERMINATION OF LEAKAGE CRACK LOCATIONS It - is a regulatory requirement that LBB be applied to an - entire -
piping system or analyzable pctrion thereof, typically segments located between anchor points. Therefore,- f or , practicality, locations-of higher maximum desigr. loads _should be determined in order to reduce the number of locations where the LBB evaluation is to be performed.
DRAFT 7A-4 July 25,-1992
_i ____________________________._____________m___ .J
l 5 SYSTEM 80+" DESIGN CERTIFICATION DISTRIEUTION SYSTEMS DESIGW GUIDE APPENDIX 7A A screening process based on comparison of the maximum design load j to crack length (i.e., applied moment to the-square of the crack !
i length "a") may be used to determine the. locations where crack stability is most likely to be challenged. These locations become the basis for loc ting leakage cracks - to be evaluated. Simple criteria may be developed for screening. For example, locations with significantly lower maximum design loading and similar NOP 1
l i loading may be eliminated from further consideration. Large I diameter pipes with low NOP and maximum design loads compared with more highly loaded locations may be elitainated. Smaller pipes are more difficult to acreen since the final margin on crack size (2) or final margin on load (V2) each have the potential of_being the limiting criterion. These two margins are equally limiting for larger pipes, which remain mostly elastic.
1.3.2 FLOW RATE CORRELATION The leakage crack size-should be correlated.to the LDS capability.
In order to simplify the LBB evaluations and provice safety margin, the value of 250 gpm/in should be used for the leakage rate in tne 2
l primary system. A value of 40 gpm/in: of condensed liquid should be used for the leakage rate in.the main steam line. _These values account for variables such as surface roughtest of the side walls of the crack,-the nonparallel relationship of the side walls due to t- the elongated crach shape, and possible - cig-zag tearing of the
- material during crack formation. The selection of'the respective
' value above as a conservative lower bound is supported by NUREG/CR 4572, "NRC Leak-Before-Break (LBB) Analysia- Methods- for Circumferentially Through-Wall Cracked _ Pipes Under Axial. Plus
. Bending Loads". For example, in order for 10 9pm-leakage to occur
! at a rate of 250 gpm/in , the leakage area should be 0.04 in 2.
Similarly, in order for 10 gpm leakage to occur at a rate of 40 gpm/in2 , the leakage area should be 0.25 in 2. These respectiva crack opening areas should be used to determine.the length of thw E detectable leakage crack for stability evaluations unless_another i
correlation is justified.
1.3.3 PRELIMINARY LBB - EVALUATION USING EPRI/GE ESTIMATION OR
- SIMILAR METHOD (Where Applicable)
The approach being taken toward design certification of System 80+
~
i is to include LBB considerations in the piping design. One aspect of the LBB evaluation pursued for each selected piping system-is performance of a preliminary LBB' evaluation prior to and-independent of pipe routing. This evaluation is used to provide the piping-designer with LBB acceptance criteria,--in terms.of a range of materials, pipe siz t and NOP and maximum design loads for all locations on the pipe. If the acceptance. criteria is met, an-acceptable result of the LBB evaluation of the final design is assured. The range of piping parameters developed by this j 1
DPMT 7A-5 July 25, 1992
SYSTEM 80+" DESIGN CERTIFICATION DISTRICUTTON SYSTEMS DESIGN GUIDE APPENDIX 7A preliminary evaluation forms a "winaow" of acceptance criteria ,
which the piping designer car. utilize to route, design and uupport the piping system.
The preliminary LBB cvaluation does not require determination of specific leakage crack locations, detailed analysis of finite element crack models, or prior calculation of NOP or SSE pipe loads. Crack opening areas may be calculated for large diameter pipes using methods such as the EPRI/GE estimation method of elastic-plastic fracture mechanics. The EPRI/GE estimation method relies on a catalog of pre-analyzed pipes for a variety of sizes and material behavior. For smaller diameter pipes, the finite element analyses described in Appendix 7A, Section 1.3.4 are performed.
The evaluation of crack opening areas vs, crack lengths is performed first. The EPRI/GE estimation or similar method requ;;es the material stress-strain properties to be in the form of the Ramberg-Osgood law (NP-1931, "An Engineering Approach for Elastic-Plastic Fracture Analysis") . The preliminary analysis utilizes best available material properties for the -rance of materials being evaluated. The Ramberg-Osgood law is fit to represent many stress-strain curves of a range within a generic type of material (e.g.,
three different types or grades of stainless steel) . Using the material properties in the form described above, the EPRI/GE method i is used to calculate the crack mouth opening displacements for various cracx longths. The crack opening areas are estimated from the crack lengths and opening displacements using an elliptical approximation for the opening areas.
Next, the leakage rates are computed from the crack lengths and ,
opening areas. The pressure-only load and a minimum NOP load are used to create a range of loads and a corresponding range of crack lengths. The results-are leakage rate vs. crack length curves.
The J-integral curves are then calculated using the J-integral estimation methods of the EPR!/GE or a similar method. J-integral
, enrves are calculated for the leakage crack sizes for both (NOP +
Maximum Design Load) and 42 x (NOP + Maximum Design Load) . The applied loads are chosen to create an acceptance range. ,
For some piping systems, this method creates a " window" of design requirements for the piping design. In cases where this " window" is developed, there could be a larger range of acceptable loads beyond the window than the preliminary estimation method generates, for two reasons:
A. The uet;iled piping nesign ultimately provides actual NOP loads, maximum design loads, and piping design parameters DRAFT 7A-6 July 25, 1992
_ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ J
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SYSfEN 80+" DESIGN CERTIFICATION DISTRIEUTION SYSTEMS DESIGN GUIDE APPENDIX 7A for the detailed finite element analysis of the crack in the final LBB evaluation.
B. The crac.. length in the detailed analysis may he based on
~
calculated rather than conservatively low NOP loads, and will therefore be shorter.
Design of the piping system to the LBB requirements developed using the above approach will therefore assure that LBB will be de-tor.atrated in the final design.
1.3.4 DETAILED FINITE ELEMENT ANALYSIS Detailed finite element LBB analyses are performed as a preliminary analysis at the design certification stage, for pires for which the estimation method (Appendix 7A, Section 1.3.3) is too conservative or inapplicable. A finite eierent analysis model is used to
- analyze the bounding crack cases in detail. For each location in the piping system where a detailed evaluation .s performed, at least two finite element modele are develc; d. One model approximating the leakage crack size at normal c erating loads is used to demonstrate safety margin on the loads. The other model, having a crack length twice that of the first adel, is used to demonstrate the margin on crack size. Additiona rack lengths may be modelled in order to better define the J_ egral vs. crack length relationship.
A three-dim?nsional isoparametric brick elemen; is used ir. *he detailed analysis model. Symmtry is usen to min. tize the size of each model analyzed. Constraints are imposed on the--models based on symmetry. The crack surface area is free from constraint in the direction uf the crack opening. External pipe loads are applied to the pipe typically at a distance of five times the radius of the pipe in order to minimize local effects in the cracked region of the pipe.
The detailed analyses of cracks in pipe welds require consideration of the properties of the pipe and the weld materials. Per CESSAR-DC, Section 3.6.3.5, the LBB analysis of cracks in pipe welds results in a bounding case when the material c_ress-strain properties of the base metal, which has the lower yield, and the fracture properties of the weld, which has the lower toughness, are used in combination for the entire structure analyzed. CESSAR-DC, Section 3.6.3.5 summarizes materials selected for System 80+ piping systems evaluated for LBB. For preliminary LBB evaluations, the stress-strain curve and J-integral are developed from best 6 available information. For final LBB evaluations, the stress-l strain curve and J-integral are developed by testing representative l samples of piping material to be used in the piping system being l evaluated. The ductile fracture parameter, J-integral, is used to l
l DRAFT 7A-7 July 25, 1992
_i
SYSTEM:80+" DESIGN CERTIFICATION DISTRICUTION SYSTEMS DESIGN GUIDE APPENDIX 7A characterize the propensity for crack extension and stability in the piping material under consideration.
The primary loading on the pipes are those occurring during NOP.
It is this loading condition which is useri'to determine - leakage crack size. Crack opaning areas are calculated at-each bounding location for-normal operating conditions. For a 10 gpm flow rate, the opening areas given in Appendix 7A, Section 1.3.2 are used to determine the leakage crack length.
The NOP and maximum design load combinations are used in the analysis to envelope the loads. The loads applied are as follows:
A. Pressure Loads The internal pressure is applied to the inner-surface of the pipe, -and_ the average pressure is applied to the crack face to account for _ the pressure _ drop from internal to atmospheric pressure across the crack. A longitudinal end foruc emilibrating the pressure is applied remote .from-the crack. ac first-incremental load step is scaled to the first yield of the pipe _ material. Subsequent loading I-is applied until full pressure is reached. J B. Normal Operation Loads The axial force and bending moment- is applied to the remote end of the model. The loads _are-applied in small increments. This method of load application allows the analysis to precisely follow the stress-strain curve of the material.
C. Maximum Design ' Loads (Largest .of_the-; Safe Shutdown Earthquake Loads, _ Critical Thermal- Transient Loads,- or-Normal Operation Dynamic-Transient Loads)
The same procedure followed for the NOP loads is used for the maximum design loads. These loads are- applied incrementally to the model which is loaded by the pressure and normal-operation loads.
To evaluate margin on loads, all the loads used in. Steps A to C above are added- together and then increased to- demonstrate additional margin, per NUREG-1061, volume 3. The additional. loads are applied to the model so that the: total load applied is equal to V2' times (Pressure t NOP + Maximum Design Load). The resulting J-integral value_is compared to the material fracture properties in -
? order to demonstrate crack stability. The final-LBB criteria-are J < Jm and dJ/da < dJm/da for the crack sizes and loading-previously given.
DRAFT 7A-8 July 25, 1992
SYSTEM 80+* DESIGN CERTIFICATION DISTRI UTION SYSTEMS DESIGN' GUIDE APPENDIX 7A To evaluate margin on crack size, the model with a crack size-twice
~
the assumed leakage crack length is' used, . per NUS.EG-1061, Volume 3.-
The pressure and moment loads are applied in the same fashion. The-sum of the loads applied is equal to (Presse.re + NOP +-Maximum Design Load) .
The J-integral technique is used to demonstrate crack stability with the margin on load and margin.on crack size. The J-integral is determined in the finite element analysis for pressure, NOP and maximum design loadings for the: two 'or more crack lengths for each geometric model. The_ stability evaluations are made by comparing the J vs . ' "a" and J, vs. "a", where "a" - is the crack- size.
Intersection of the curves illustrates that crack stability is assured, indicating that LBB' is_-demonstrated fcr the crack ,
evaluated.- Crack stability is assured.for each location in a given piping system where the loads are within the window analyzed, which demonstrates-LBB for that piping system.
2.0 APPENDIX 7A REFERENCES 2.1 NUREG-1061, Volume 3, " Evaluation of Potential for Pipe Breaks", November 1984.
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2.2. NUREG/CR 4572 (BMI-2134), "NRC Leak-Before-Break(LBB)-
Analysis Methods for Circumferentially Through-Wall Cracked Pipes Under Axial Plus Bending Loads", R. Klecker, F. Brust, G. Wilkowski, May, 1986.
2.3 EPRI Report No. NP-1931, "An Engineering .. Approach for Elastic-Plastic Fracture Analysis",.V. Kumer, M..D. German and C. F. Shih, July, 1981.
2.4 USNRC Regulatory Guide 1.45, " Reactor Coolant Pressure Boundary Leakage Detection Systems",-May;1973.
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DRAFT 7A-9 July 25, 1992
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4 SYSTEM 80+* DESIGN CERTIFICATION i DISTRIGUTION SYSTEMS-DESIGN GUIDE APPENDIX 7B e
e i 1.0 FUNCTIONAL CAPABILITY REQUIREMENTS 2
ASME Code Class 2 and 3 stainless steel elbows should be considered to meet the functional capability criteria when the -following
{- . equation is met. Functional capability evaluations are only
' required on elbows with D,/t > 50.
i i
s1.8SY (Eqn. 7B-1)
B + B.
i \ 2cj 't 2j i~
s 4 Where: 31 = (-0.1 + 0. 4h) , and 0$B 6~0.5 1
i j And: B-i = 0.5 for B, = 1.0 B, = 1.3/h'8-2 for a, > 90*
]
i = 0 . 8 9 5 / h'*"8 for =, = 90*
3 = 1.0 for =, = 0' i
but not less than 1.0 Linear interpolation is allowed for values of =,
l.
between O' and 90'.
h = tR/r 2 1
f =, = angle of the bend i
- R = elbow bend radius (inch) mean radius of pipe (inch) -l r
f
!' P = pipe design pressure -(psig),
i
, D. = pipe outside diameter (inch) t = nominal pipe wall thickness (inch).
M3 = moment associated with-plant' faulted loads-Sy = yield strength of material at design temperature Z = section modulus (in ) 8 i
-DRAFT 7B-1 July 25, 1992