Nuclear Power Technology Development

IAEA Coordinated Research Projects (CRP)

Heat Transfer Behaviour and Thermo-hydraulics Code Testing for SCWRs


There is high interest internationally in both developing and industrialized countries in innovative super-critical water-cooled reactors (SCWRs), primarily because such concepts will achieve high thermal efficiencies (44-45%) and promise improved economic competitiveness utilizing and building on the recent developments for highly efficient fossil power plants. The SCWR has been selected as one of the promising concepts for development by the Generation-IV International Forum.

In support of Member States' efforts in the area of SCWRs, the IAEA started in 2008 a Coordinated Research Project (CRP) on "Heat Transfer Behaviour and Thermo-hydraulics Code Testing for SCWRs". This IAEA CRP promotes international collaboration among IAEA Member States for the development of Super-Critical Water-Cooled Reactors in the areas of thermo-hydraulics and heat transfer, including the collection and gathering of experimental data relevant to supercritical fluid behaviour as well as the development and testing of the associated computer methods.

The CRP has been planned on the advice and with the support of the IAEA Nuclear Energy Department's Technical Working Groups on Advanced Technologies for LWRs and HWRs (the TWG-LWR & TWG-HWR). Comments from the Gen-IV SCWR Steering Committee have been quite useful in developing the CRP Plan. Coordination has been agreed with the OECD-NEA, which also provides the Technical Secretariat services to the Generation-IV International Forum (GIF).

Overview of the CRP

The higher coolant temperatures proposed for SCWR systems imply fuel cladding temperatures greater than current nuclear reactor operating experience. Because of enhanced heat transfer for supercritical flows and the use of new cladding materials with low corrosion rates, it is necessary to have precise information for establishing both the neutronic and the thermal limits. In addition, it is considered desirable to match the inlet conditions of existing and proven supercritical turbines.

Consequently, in developing SCWR designs, experimental data for the convective heat transfer from fuel to coolant, covering a range of flow rate, pressure and temperature conditions, are required. The collection, evaluation and assimilation of existing data, as well as conducting new experiments for the attainment of needed data are necessary to establish accurate methods and techniques for the prediction of heat transfer in SCWR cores.

Validated thermo-hydraulic codes are required for the design and safety analyses of SCWR concepts. Existing codes for water-cooled reactors need to be extended in their application and improved to model phenomena such as pressure drop, critical flow, flow instability behaviour and transition from super-critical to two-phase conditions. The appropriate predictive models for computing the heat transfer to super-critical fluids need to be incorporated into the codes, and the codes need to be tested and validated.

Thus, the two key objectives of this CRP are:

  1. To establish a base of accurate data for heat transfer, pressure drop, blowdown, natural circulation and stability for conditions relevant to super-critical fluids
  2. To test analysis methods for SCWR thermo-hydraulic behaviour, and identify code development needs

The following deliverables will be created as a result of the work performed for the CRP:

  1. A database of super-critical heat transfer and pressure drop data
  2. IAEA reports synthesizing the results and technology advancements achieved by the CRP for dissemination to Member States
  3. Joint papers by CRP participants for international meetings and technical journals

This CRP was completed in September 2012.


The following institutions are participating in this CRP:

OECD/NEA, AECL (Canada), McMaster University (Canada), UOIT (Canada), CIAE (China), SJTU (China), VTT (Finland), BARC (India), University de Pisa (Italy), KAERI (Republic of Korea), JRC/EC (Netherlands), Gidropress (Russia), IPPE (Russia), National Technical University of Ukraine (Ukraine), University of Manchester (UK), University of Wisconsin - Madison (USA)

Group Photo

5th Research Coordination Meeting (RCM) in Beijing, China, 3-6 September 2012

Research Coordination Meetings

The First Research Coordination Meeting (RCM) (restricted access) of the CRP was held at IAEA Headquarters, Vienna, Austria, 22-25 July 2008. During this first RCM the participants developed an Integrated Research Plan (IRP) that indicated how the participating organizations were to collaborate during the CRP and that specified their contributions to the various activities of the CRP.
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The Second RCM (restricted access) took place on 25-28 August 2009 also at the IAEA Headquarters in Vienna, Austria. The objective of this RCM was to review the progress on the IRP and to update it as needed for the remainder of the CRP. In addition, the RCM evaluated several proposals such as the development of a course on SCWRs, the establishment of a young researched exchange program, and the organization of an IAEA Technical Meeting on SCWR.
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The Third RCM (restricted access) took place on 23-27 August, 2010 at the IPPE Facilities in Obninsk, Russian Federation. The objective of this RCM was to review the progress on the IRP and to update it as needed for the remainder of the CRP. The RCM also evaluated the results of the two benchmark exercises conducted within the framework of the CRP. Finally, a preliminary draft of the CRP final report was compiled and timelines and responsibilities for the completion of the report and its review were established.
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The Fourth RCM (restricted access) was held at AECL Sheridan Park Office, Mississauga, Canada, 19-23 September 2011. The objective of the RCM was to review the progress during the past year, to review the draft of TECDOC on the results achieved in the CRP, to plan the next year activities, and to discuss topics relating to the CRP. The progress at each institution was presented and discussed in detail, and the plan for the next year was established including the TECDOC final draft preparation. The IAEA introduced Joint ICTP-IAEA Course on "Science and Technology of SCWRs", and the participants supported to hold the 2nd course next year.
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The Fifth RCM (restricted access) was hosted by CIAE and held at Minzu Hoel in Beijing, China, 3-6 September 2012. The objective of the RCM was to review the progress at each institution, to review and finalize the draft of TECDOC on the results achieved under the framework of the CRP, and to discuss future activities relating to the CRP. The progress during the last year and the summary of major activities during the CRP was presented by each representative. The draft of TECDOC was discussed, reviewed and finalized. Several institutions have decided to continue collaboration on a bi-lateral or multi-lateral basis even after the completion of the CRP. The database hosted by OECD/NEA will be utilized among the participants until the end of 2016.
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This CRP was completed in September, 2012

Courses on Science and Technology of SCWRs

The IAEA organized the first course on Science and Technology of Supercritical Water Cooled Reactors (SCWRs), and it was held at "Abdus Salam" International Centre for Theoretical Physics (ICTP), Trieste, Italy, 27 June - 1 July 2011. The course provided a comprehensive and up-to-date review of the science and engineering of supercritical water cooled reactor concepts, including thermodynamics, thermal-hydraulics and heat transfer, neutronics and core design, materials requirements, system design and safety aspects.

The second course was held at McMaster University in Mississauga, Canada, 16-21 July 2012, in cooperation with the IAEA. The course program had been improved based on the feedback from lecturers and participants of the first course. The course was attended by 21 participants from 7 Member States, and provided 24 lectures.

The third course was held at Shanghai Jiao Tong University (SJTU) in Shanghai, China, 26-30 August 2013, in cooperation with the IAEA. It was attended by 22 participants from 6 Member States, and provided 21 lectures.

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