0

Full Content is available to subscribers

Subscribe/Learn More  >

Modelling and Analysis of Loviisa NPP Pilot Operated Main Steam Safety Valves

[+] Author Affiliations
Mika Juntti

Fortum Power and Heat Oy, Espoo, Finland

Paper No. ICONE25-66705, pp. V006T08A051; 8 pages
doi:10.1115/ICONE25-66705
From:
  • 2017 25th International Conference on Nuclear Engineering
  • Volume 6: Thermal-Hydraulics
  • Shanghai, China, July 2–6, 2017
  • Conference Sponsors: Nuclear Engineering Division
  • ISBN: 978-0-7918-5784-7
  • Copyright © 2017 by ASME

abstract

Loviisa NPP (unit 2) low pressure Main Steam Safety Valves (MSSV) were renewed during 2014 overhaul. New valves are pilot operated and qualified for two phase conditions. The old valves were spring loaded and qualified only for steam flow conditions.

During the testing of new MSSVs, unexpected behavior was detected. The opening of new MSSV included significant delay in case of repeated openings. This led to a need to investigate this phenomena more closely since such opening delay could have negative impact to plant safety.

This paper presents the aftermath of the discovered opening delay in the NPP and describes how thermal hydraulic modelling and analyses were used to gain in depth understanding of pilot operated MSSV. In addition, it is presented how the analysis work was used to solve the discovered challenges.

Modelling work was conducted using Apros Process Simulation Software [1] which is the main tool for deterministic safety and engineering analysis of Loviisa NPP [2–4].

Copyright © 2017 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