Piping Analysis

Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Piping Analysis
Madhur Paharia
AP1000, the AP1000 logo, and the phrase, The Nuclear Renaissance Starts Here.
are trademarks or registered trademarks of Westinghouse Electric Company LLC,
its subsidiaries and/or its affiliates in the United States. These marks may also be
used and/or registered in other countries throughout the world. All rights reserved.
Unauthorized use is strictly prohibited.
1
Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Agenda
• Piping Scope
• Piping Analysis
• Primary Equipment
• Interfaces
• Additional Requirements
• Advantages of Design
What questions do you have?
2
Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Piping Scope
• What is Piping?
– Is an arrangement of straight and bent pipe/tube connected by
components, fittings, and welds.
– Provides a fluid path that interconnects two or more pieces of
equipment at different locations
– Does not perform a process function
– Expansion volume
– Fluid mixing
– Heat transfer between different process fluids
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Piping Scope
• How much piping is there? 34 mi or 55 km
• About 80% less safety related piping than in typical PWR’s
Total Length per Pipe Size
12
16
14
10
12
8
Miles
10
6
8
Kilometers
6
4
4
2
2
0
0
≤ 1"
2"
3"
4"
6"
8"
10"
12"
14"
16"
20"
24"
30"
36" Other
Nominal Pipe Size
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Piping Scope
• What materials are used?
1%
Materials
5%
Carbon (A106)
29%
Low Alloy (P11)
Stainless(304L)
Stainless(316LN)
57%
Other
8%
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Agenda
• Piping Scope
• Piping Analysis
• Primary Equipment
• Interfaces
• Additional Requirements
• Advantages of Design
What questions do you have?
6
Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Piping Analysis Approach
• Analyze pipe and fluid weight
• Analyze seismic loading
• Analyze thermal expansion of pipe
– System operating modes
– Environmental thermal events
• Analyze hydrodynamic loads due to system operation
– Valve opening/closure
– Pump starts/stops
– Squib valve actuation
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Seismic Analysis
Vertical Direction
X – Direction
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Piping Analysis Approach (cont.)
• Structural analysis (with PIPESTRESS) is performed to
ensure that piping is properly designed and supported to
meet various requirements
–
–
–
–
Move pipe centerline
Locate pipe supports
Change pipe materials or components
Special calculations if necessary (Detailed Analysis)
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Isometric
Example
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
PipeStress
Snapshot
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Support Example – Strap
Pipe Strap
Overlay Plate
Plate Steel
Tube Steel
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Support Example – Strut
Weld Bracket
Steel
Rigid Strut
Rigid Strut
Clamp
Weld Bracket
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Support Example – Constant Load
Tube Steel
Clevis with Pin
Weld-on Eye Plate
Constant Hanger
Threaded Rod
Pipe Clamp
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Support Example – Snubber
Tube Steel
Weld-on Bracket
Shock Absorber
Pipe Clamp
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Agenda
• Piping Scope
• Piping Analysis
• Primary Equipment
• Interfaces
• Additional Requirements
• Advantages of Design
What questions do you have?
16
Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Primary Equipment
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Primary Equipment
• Reactor Coolant Loop
– Reactor Coolant Pumps directly attached to Steam Generators
– No cross-over leg
– No Reactor Coolant Pump supports
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Reactor Coolant Pump (RCP) Typical
Standard Supports (Tension Rod)
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Reactor Coolant Pump Supports
AP1000 (SG + Cold Leg Nozzles)
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Primary Equipment
• Reactor Coolant Loop
– Steam Generator supported by one vertical column with lateral
struts and snubbers
– No shimming required to engage lateral restraints
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Steam Generator (SG) Bumper
Supports – Plant Typical
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Steam Generator Supports – AP1000
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Primary Equipment
• Integral Nozzles
– No weld, no inspection required
• Unique Surge Line Routing
– Surge Line thermal monitoring program
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Surge Line Configuration
25
Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Agenda
• Piping Scope
• Piping Analysis
• Primary Equipment
• Interfaces
• Additional Requirements
• Advantages of Design
What questions do you have?
26
Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Interfaces
• Nuclear Systems and Balance of Plant
– Piping and Instrumentation Diagrams (P&ID) and Operating conditions
• Plant Layout
– Locate Piping
• Auxiliary Equipment
– Termination points to Piping
• Valve
– Supported in-line by Piping
• Mechanical Modules
– Fabricated package with piping and pipe supports
• Civil/Structural
– Seismic Response Spectra and Embedments
27
Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Interfaces (cont.)
• Regulator
– Meet Industry Standard
– ASME Boiler & Pressure Vessel Code Section III
– ASME Design Specifications
– ASME Design Reports
– Meet Additional Requirements
– Standard Review Plan
– Design Control Document
– Pipe Rupture Hazards Analysis
– Leak Before Break Program
28
Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Agenda
• Piping Scope
• Piping Analysis
• Primary Equipment
• Interfaces
• Additional Requirements
• Advantages of Design
What questions do you have?
29
Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Pipe Break Hazard Evaluation
• Additional requirements, from the regulator, beyond
ASME Code for high-energy piping
– T >200oF (93oC) or P >275 psi (1.9 MPa)
– Postulate break locations
– Terminal ends
– Locations of high stress or fatigue usage factor
– Identify rooms, breaks, and safety-related targets
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Pipe Break Hazard Evaluation
• Identify how to protect equipment from break effects
– Redundant systems
– Analyze
– Calculate pipe whip plastic hinges and jets associated with
breaks
– Separate
– Protect (barriers, pipe whip restraints)
31
Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Leak Before Break (LBB)
• Program to eliminate postulation of breaks
• It is postulated that the leak caused by a crack can be
detected before a break occurs
• The detection of the crack would alert operators, allowing
remediation
• Requires leak detection system and piping configuration
that can support a crack with stability
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Leak Before Break (cont.)
• Implement leak detection system (typical of 0.5 gallons
or 1.9 liters per minute, gpm or lpm)
– Containment sump level
– Humidity monitors
– Radiation monitors
• Apply a safety factor of 10x on minimum detectable
leakage (5 gpm or 19 lpm)
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Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Leak Before Break (cont.)
• Determine crack given leakage rate
• Apply a safety factor of 2x on the crack size
• Determine normal and maximum stress levels (bounding
analysis curve) that allow for stability of the crack
34
Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Leak Before Break (cont.)
• Bounding analysis curve generated for each line size,
temperature, pressure, material
• Normal stress versus maximum stress
• If critical stress is at or below bounding analysis curve,
piping meets LBB
• AP1000 has LBB for the high-energy line inside
containment ≥6" (15.24 cm)
• Notable exceptions
– 4" pressurizer spray line (15.24 cm) does not meet minimum size
requirements
– NRC has not granted LBB for main feedwater and startup
feedwater lines
35
Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Leak Before Break (cont.)
AP1000
Typical Bounding Analysis Curve (BAC)
Line Number(s):
60
50
Point "B"
40
Notes for Typical Bounding Analysis Curve:
Point "A" - for low normal case to generate BAC.
Point "B" - for high normal case to generate BAC.
Point "A" and Point "B" are joined by a straight line.
Point "1" - analyzed critical point which meets LBB criteria.
Point "2" - analyzed critical point which fails LBB criteria.
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Point "2"
*
20
*
Point "A"
Point "1"
10
0
0
5
10
15
Normal Stress (ksi)
20
25
30
36
Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Agenda
• Piping Scope
• Piping Analysis
• Primary Equipment
• Interfaces
• Additional Requirements
• Advantages of Design
What questions do you have?
37
Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Advantages
• Enhancements in piping area for AP1000 vs. standard
plants
–
–
–
–
–
–
–
–
–
Design for maintenance inspectability
Bends vs. elbows in loop and piping systems
Minimize snubbers
Reactor coolant loop (RCL) layout
Integral nozzles in primary loop piping
Primary equipment supports
Maximize use of Leak Before Break
Minimize pipe whip restraints (0 for RCL)
Overall less piping in AP1000
38
Westinghouse Non-Proprietary Class 3
© 2011 Westinghouse Electric Company LLC. All Rights Reserved.
Questions
39

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