Session: OAC-07-01: Plant Life Extension: Aging and Life Management

Paper Number: 84008

84008 - An Update of the Assessment Methodology for Civil Ageing Management: Damage Development in Concrete Structures of a Reactor due to Ageing Mechanisms 

The nuclear power plants (NPP) worldwide are operating for longer times in order to increase the service life of the structures beyond their initial design parameters. This extension of operation period has developed the necessity to manage the ageing mechanisms that may occur. As the operation period increase, the importance of the structural integrity of the civil structures and the knowledge of the ageing mechanisms increases as well.

Specially civil concrete structures seek more interest and need a good understanding of its behavior due to their ambient conditions or external agents. The aim of this paper is to gain knowledge about the concrete properties in the civil structures of the High Flux Reactor (HFR) in Petten and subsequently reach an assessment methodology for the ageing mechanisms that may occur.

In a first step, the material of the HFR will be investigated and the behavior of the structural concrete will be explained. The characteristic properties of the concrete will be evaluated and the results of the inspection on the concrete of the civil HFR structures will be compared. The degradation mechanisms that may occur will be identified and referred according to their impact with the rest of the structure.

In a second step, a practical assessment in finite modelling techniques will be introduced in order to take into consideration the degradation of the concrete. The material properties will be analyzed and adapted in an FE Model. In addition the behavior of structural concrete will be explained. The aim is to create a predictive tool with the FE modelling technique for the damage quantification in concrete due to its ageing mechanism

 

Presenting Author: F.H.E De Haan -de Wilde NRG

Presenting Author Biography: Ciska has a master degree in aerospace engineering from the TU Delft (The Netherlands). After experience in the aerospace and wind energy sector she is now working for more than 13 years at NRG. Currently team manager of a team of mechanical engineers supporting the HFR research reactor (producing medical isotopes), external clients and research. We are help other to decide with nuclear code is applicable and does the system, structure or component fulfill the criteria? Ciska has experience on environmental fatigue, seismic, long term operation and asset management topics.

Authors:

F.H.E De Haan -de Wilde NRG
Ledia Hasa NRG