Prediction of Axial and Radial Creep in Pressure Tubes

Closed for proposals

Project Type

Coordinated Research Project

Project Code




Approved Date

19 April 2012


3 - Active - Ongoing

Start Date

30 October 2012

Expected End Date

30 October 2017

Completed Date

29 November 2018

Participating Countries

Republic of Korea


Pressure tube deformation is a critical ageing issue in operating heavy water reactors (HWRs). Depending on the years of service, horizontal pressure tubes may show one of three kinds of deformation: diametral creep leading to coolant flow bypass in the fuel bundles and a related penalty to the critical heat flux for fuel rods; longitudinal creep leading to disruption of the feeder pipes and/or the fuelling machine; and sagging leading to interference with in-core components and potential contact between the pressure tube and calandria tube. The CRP scope includes the establishment of a database for pressure tube deformation, microstructure characterization of pressure tube materials collected from HWRs currently operating in Member States, and development of a prediction model for pressure tube deformation. The CRP has been planned on the advice and with the support of the IAEA Department of Nuclear Energy’s Technical Working Group on Advanced Technologies for Heavy Water Reactors. The CRP is conducted by the Nuclear Power Technology Development Section within the Department of Nuclear Energy.


To promote international collaboration among IAEA Member States through the sharing the data and participating in the development of prediction model and microstructure characterization of pressure tube materials for operating heavy water reactors.

Specific objectives

To improve safety for currently operating plants and to facilitate more economic and safe designs for future plants

Contact the project officer


Stay in touch