0

Full Content is available to subscribers

Subscribe/Learn More  >

Method for Unified Safety Assessment With Respect to Plastic Collapse in Design and In-Service Defect Analyses

[+] Author Affiliations
Petter von Unge

Inspecta Technology AB, Stockholm, Sweden

Björn Brickstad

Swedish Radiation Safety Authority, Solna, Sweden

Paper No. PVP2017-66199, pp. V01BT01A051; 8 pages
doi:10.1115/PVP2017-66199
From:
  • ASME 2017 Pressure Vessels and Piping Conference
  • Volume 1B: Codes and Standards
  • Waikoloa, Hawaii, USA, July 16–20, 2017
  • Conference Sponsors: Pressure Vessels and Piping Division
  • ISBN: 978-0-7918-5791-5
  • Copyright © 2017 by ASME

abstract

The purpose of this work is to establish a method for safety assessment with respect to plastic collapse, which is consistent for design assessment in accordance with Section III of the ASME Boiler and Pressure Vessel Code and assessment of in-service defects.

In the Swedish nuclear power industry, a procedure is used for assessment of in-service defects that is based on failure assessment diagrams according to the R6-method combined with a safety evaluation system corresponding to Section III and XI of the ASME Code. The Swedish procedure was originally based on R6 Revision 3 combined with the 1995 edition of the ASME Code. In recent years the procedure has been updated to correspond to current versions of R6 and ASME. These updates include a transition to the updated definition of flow stress as well as structural factors against plastic collapse that was included in the 2002 Addenda of ASME 2001 Section XI.

Following these updates, discrepancies were found between plastic collapse analyses made in accordance with Section III and assessments of in-service defects. Due to this, a project was initiated to make the procedure for assessment of in-service defects consistent with Section III analyses. An in-depth study of the flow stress definitions and structural factors in Section XI was initiated. This study found that the structural factors are based on approximations to get material independence. These approximations uses mean values based on a number of materials which was found to be quite inaccurate for many materials used in the Swedish nuclear power industry and can differ up to about 15 % compared to Section III analyses.

A method has been developed to calculate material specific structural factors that gives a near perfect match between plastic collapse according to Section III and the Swedish procedure for assessment of cracks. The method is based on the methodology for structural factors in Section XI, but excludes the assumptions made to get material independent structural factors. The method is presented and comparisons show the agreement to Section III and highlight cases of large discrepancies in Section XI.

Copyright © 2017 by ASME
Topics: Safety , Design , Collapse

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In