11 Subsection NG — Core Support Structures Available to Purchase

This Chapter provides commentary and practical examples on the materials, design, fabrication, installation, and examination requirements for Core Support Structures (CSS) in Section III, Division 1, Subsection NG of the ASME Boiler & Pressure Vessel (ASME B&PV) Code [1]. In addition, commentary is provided on Section XI [2] of the Code, as the rules apply to CSS repair, replacement, examination, and inspection requirements.

The 4th Edition of this Chapter has been updated to reflect the 2010 Edition of the ASME B&PV Code with 2011 Addenda, and includes commentary on the following topics:

• Background on Subsection NG Development

• Definition of Class CS and Jurisdictional Boundaries

• Discussion of Typical Materials Used

• Design By Analysis Rules and Allowable Limits

• Owner's Design Specification and Design Reports

• Fabrication, Installation, and Examination

• Environmental Effects

• Selected Interpretations and Code Cases Applicable to NG

• Improvements and Future Developments in Subsection NG

• Material Degradation Issues

• Compatibility of Subsection NG with Other International Codes

• Realistic Design Loads for Reactor Internals

• Summary of Changes to 2010 Edition of the ASME Code for CSS