1 Westinghouse Non-Proprietary Class 3© 2012 Westinghouse Electric Company LLC. All Rights...

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Westinghouse Non-Proprietary Class 3 © 2012 Westinghouse Electric Company LLC. All Rights Reserved.

Structural Analysis of a Nuclear Fuel Handling Machine Overview

By: Steve Sherfey, Westinghouse Electric Company LLC

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Agenda

• Abstract

• Analytical Model

• Hoist & Hook Model Configurations

• Acceptance Criteria and Codes

• Service Condition

• Seismic Condition

• Special Modeling Technique

• Primary and Secondary Evaluations

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Abstract

• Nuclear Power Plants contain Fuel Handling Machines (FHMs) for moving fuel

• Rail Mounted, Motorized, and Computer controlled

• Very top heavy

• Very difficult to qualify

• Engineers must use a special modeling technique for qualification

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Analytical Model

Lower Rail & Wheel

Motor

Upper Rail

Upper Bridge Lower Bridge

Lower Rail & Wheel

Power Center

SFP Hoist

Main Hoist

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.

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Analytical Model - Inputs

• Design Drawings

• Boundary Conditions

• Material and Sectional Properties of Structural Components

• Proper member releases at bolted connections

• Response Spectra for the SSE Event

• Create analytical model using Structural Analysis Computer

Code such as GTStrudl

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Analytical Model – Material Properties

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Analytical Model – Sectional Properties

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Analytical Model Response Spectrum (X Direction)

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Analytical Model Response Spectrum (Y Direction)

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Analytical Model Response Spectrum (Z Direction)

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Analytical Model

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Hoist & Hook Model Configurations

Main Hoist at Mid Span, SFP Hoist at North End.

Main Hoist at North End, SFP Hoist at South End.

Main Hoist at North End, SFP Hoist at Mid Span.

N

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Acceptance Criteria and Codes

• Plant Design Specification & Response Spectra

• AISC Manual of Steel Construction, Allowable Stress Design

• ASME NOG-1, Rules for Construction of Overhead and Gantry Cranes

• ASME B&PVC Code, Section III, Division 1, Sub-Section NF

• CMAA-70, Crane Manufacturers Association of America, “Specifications for Top Running Bridge & Gantry Type Multiple Girder Electric Overhead Traveling Cranes”

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Service Condition

• Analyzed for all service loads without seismic excitation and qualified per CMAA-70

• Loadings shall include Inertia of mass loads from movement of Crane, Trolley, Hoist, and Lifted Load

• Loadings due to Wind, Skewing, Collision, Platform, and maximum critical hook loads shall be considered when applicable.

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Seismic Condition

• Analyzed for all normal operation deadweight loads acting simultaneously with seismic excitation from Safe Shutdown Earthquake (SSE)

• Response spectrum method shall be used– Proper Combination of modes of seismic vibration

– Proper Combination of directional seismic responses

– Proper Damping factors

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Special Modeling Technique

• Sliding or rolling must be considered to prevent overturning

• Force required to cause sliding or rolling must be calculated

• Each crane drive wheel is restrained in the movement direction with a specified spring stiffness

• The spring stiffness is derived by iteration

• An initial stiffness is assumed; the value is changed & analysis rerun until the wheel seismic load equals the sliding/rolling force.

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Required Crane Evaluations

Primary Evaluations:

Wheel Reactions, Displacements, Accelerations, Structural Steel Stresses, Plate Element Stresses

Secondary Evaluations:

Welds, Beam Connection Plates, Beam Flange/Web Deformations, Stiffener Plates, Bolts, and Wire Ropes

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Some Typical Items Being Evaluated

THE END

M SHAPE TO W SHAPE CONNECTION

TUBE ON TUBE CONNECTION

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Bolt Evaluations

• The maximum forces and moments for each connection type can be extracted from GTStrudl

• 30-40 types of major bolted connections in the FHM

• Can be grouped in 10-15 typical connection types

• Each connection type has a different bolted configuration pattern due to size, number, and spacing of bolts

• Each configuration has different sectional properties required for calculating max shear and tension stresses

• Bolts must be qualified to applicable code

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Slack Rope Evaluations

• If the lifted load has an upward seismic acceleration greater than 1 g, the hoist wire rope may need to be evaluated for the slack rope condition

• ASME NOG-1 provides design guidance for performing this evaluation

• The maximum slack rope allowable is based on a percentage of the rope breaking strength

• A non-linear time history analysis is normally required for performing the slack rope analysis

• The analysis is only used for evaluating the rope for the most probable lifted load condition

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Structural Analysis of a Nuclear Fuel Handling Machine

THE END

1 Westinghouse Non-Proprietary Class 3© 2012 Westinghouse Electric Company LLC. All Rights...

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Transcript of 1 Westinghouse Non-Proprietary Class 3© 2012 Westinghouse Electric Company LLC. All Rights...