The LORELEI Test Device – Brief Presentation and Current Status of the Project

One of the challenges in designing a nuclear power reactor is to overcome the inherent safety issues. The LORELEI experimental device [1], which is destined to be located in the Jules Horowitz experimental Reactor (JHR) [2], Cadarache, France, is a single rod test device that examines the phenomena of a Loss of Coolant Accident (LOCA). Leading the LORELEI project are the French Atomic Energy Commission (CEA) and the Israel Atomic Energy Commission (IAEC), within the framework of the JHR international consortium.

The work on the LORELEI device has started in Rotem Industries in the end of 2011, where currently final stages of the detailed design are being made in preparation for the manufacturing phase.

The LORELEI device main component is a long and thin double walled pressure vessel, in where a single fuel rod is located. The device is placed near the JHR core, in order to absorb the neutron flux necessary for the generation of nuclear reaction. The fuel rod is cooled by thermo-syphon flow of water, where the resultant heat is removed to the JHR pool through the vessel`s double wall. During the critical phase of the experiment, the water are emptied from the experimental volume and temperature escalation leading to the burst of the fuel rod cladding is expected. In addition to the fuel rod, the experimental volume also contains: tubing, heaters, thermocouples and LVDTs, that control and monitor the various experimental stages.

The operational requirements, including a variety of working situations, required complex thermos-hydraulic, mechanical and seismic calculations that were done using various numerical and analytical calculations. Furthermore, for the safety important equipment, the structural calculations are done according to the RCC-MRx code for nuclear components [3].

Another challenge is a space and interfaces limitations that increased the complexity of the design of the equipment and components, regarding thermo-mechanical and manufacturing aspects.

Due to the nature of the LORELEI experiment that includes bursting of the fuel cladding, and its proximity to the reactor core, the device is subjected to strict safety and quality assurance regulations, design codes and procedures of the highest standards. These are also assured by the involvement of an appointed French regulatory Agreed Notify Body for what concerns nuclear pressure equipment [4].

These and other challenges and the project status will be discussed during the presentation with more details.

References

[1] N. Moran, L. Ferry, A. Azulay, O. Mileguir, Y. Weiss, M. Szanto, "Concept of the LORELEI Test Device for LOCA Experiment in the JHR Reactor", European Research Reactor Conference RRFM 2014, 30 March – 3 April, 2014, Ljubljana, Slovenia.

[2] G. Bignan, J. Estrade, “The Jules Horowitz Reactor: a new high performances European MTR Material Testing Reactor) with modern experimental capacities: toward an international user facility”, international Group on Research Reactors - IGORR 2013, October, 13-18, 2013, Daejeon, Korea.

[3] Afcen, RCC-MRx, 2012 edition, "Design and Construction Rules for Mechanical Components of Nuclear Installations"

[4] French Order dated 30 December 2015 concerning nuclear pressure equipment (ESPN) – "For Nuclear Pressure Equipment"