0

Full Content is available to subscribers

Subscribe/Learn More  >

Overpressure Fragility Evaluation of a Mark I Drywell Using Thermal-Mechanical Finite Element Analysis

[+] Author Affiliations
Mohamed M. Talaat, David K. Nakaki, Philip S. Hashimoto

Simpson Gumpertz & Heger, Inc., Newport Beach, CA

Kyle S. Douglas

Simpson Gumpertz & Heger, Inc., San Francisco, CA

Yahya Y. Bayraktarli

BKW FMB Energie AG, Mühleberg, Switzerland

Paper No. PVP2014-28623, pp. V002T02A005; 8 pages
doi:10.1115/PVP2014-28623
From:
  • ASME 2014 Pressure Vessels and Piping Conference
  • Volume 2: Computer Technology and Bolted Joints
  • Anaheim, California, USA, July 20–24, 2014
  • Conference Sponsors: Pressure Vessels and Piping Division
  • ISBN: 978-0-7918-4599-8
  • Copyright © 2014 by ASME

abstract

The overpressure fragility of a Mark I boiling water reactor drywell was performed by detailed finite element (FE) analysis. The drywell overpressure capacity is controlled by the onset of leakage in the bolted head flange connection once separation exceeds the capacity of the silicone rubber O-ring seals.

The FE analysis was conducted at 6 discrete accident temperatures, ranging from 150 to 425°C. The overpressure evaluation used an axisymmetric model of the drywell head region for computational efficiency, and verified it by comparing to results from one FE model which used 3D solid elements. The mechanical properties of the steel materials were defined as temperature-dependent linear-elastic.

The median overpressure capacity at each temperature was determined using a 2-step thermal-stress analysis procedure. First, a steady-state heat transfer analysis was conducted to map out the temperature distribution in the drywell wall, which is exposed to the accident temperature on the inside and ambient temperature on the outside. Second, a quasi-static multi-step stress analysis was performed. The vertical differential movement between the flange surfaces was monitored and compared to the O-ring rebound capacity to define the pressure at the onset of leakage. After leakage occurred, the relationship between leakage area and increased pressure was recorded.

The evaluation predicted the median overpressure capacity and the lognormal standard deviation for uncertainty in O-ring rebound capacities, bolt preload, and model sophistication, in addition to the median pressure-leak area relationship.

Copyright © 2014 by ASME

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