R&D and Experimental Programs to support the ASTRID Core Assessment in Severe Accidents Conditions

F. Serre (1) , F. Payot (1) , C. Suteau (1) , L. Trotignon (1) , E. Batyrbekov (2) , A. Vurim (2) , A. Pakhnits (2) , V. Vityuk (2) , S. Kubo (3) , A. Katoh (3) , Y. Tobita (3) , K. Kamiyama (3) , K. Matsuba (3) , J. Toyooka (3)

1 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)
2 National Nuclear Center of the Republic of Kazakhstan
3 JAEA - Japan Atomic Energy Agency [Ibaraki]

The ASTRID reactor (Advanced Sodium Technological Reactor for Industrial Demonstration) is a technological prototype designed by the CEA with its industrial partners, with very high levels of requirements. Innovative options have been integrated to enhance the safety, to reduce the capital cost and improve the efficiency, reliability and operability, making the Generation IV SFR an attractive option for electricity production. In the ASTRID project, the safety objectives are first to prevent the core melting, in particular by the development of an innovative core with heterogeneous pins and complementary safety prevention devices (named CFV core), and second, to enhance the reactor resistance to severe accident by design. In order to minimize the mechanical energy releases in severe accident conditions and to mitigate the consequences of hypothetical core melting situations, specific dispositions or mitigation devices are added to the core and to the reactor.It is also required to provide a robust safety demonstration (with high level of confidence). In particular assessed codes must be used.To meet these ASTRID objectives, a large RandD program was launched in the Severe Accident domain, with a large number of partners, and in particular JAEA. This RandD program covers the approach to define the mitigation devices, the methodology to study the hypothetical severe accident situations, the development and adaptation of simulation tools, and, despite an already large existing experimental database, a complementary experimental program to reduce uncertainties.To extend the CABRI and SCARABEE in-pile test programs carried-out by CEA/IPSN at Cadarache, France, jointly funded by CEA/IPSN and Japan, with homogeneous fuel pins as used in Phenix or SuperPhenix reactors, a feasibility study is underway for running a complementary program in the Impulse Graphite Reactor (IGR) operated by IAE-NNC, with heterogeneous fuel pins. For the feasibility study, this program, named SAIGA standing for Severe Accident In-Pile experiments for Generation IV reactor and ASTRID project', is supposed to be composed of i) an unprotected loss of coolant flow test (an Instantaneous Total flow Blockage) in a heterogeneous fuel-pin sub-assembly, and ii) of power excursion tests on a single heterogeneous fuel-pin. SAIGA feasibility is studied in cooperation with NNC-RK.For studying the Fuel-Coolant Interaction, and developing mitigation devices, including in-core mitigation devices, CEA is designing a dedicated PLINUS-2 platform for out-of-pile experiments with large masses of UO2 and Sodium coolant. This paper will present-the innovative ASTRID CFV core with mitigation devices,-the associated RandD related to the SFR Severe Accident issue including othe CFV core behavior in Severe Accident Situations, the CABRI, SCARABEE programs and SAIGA program feasibility,oThe Corium Relocation out of the core through dedicated Ducts, the EAGLE1et2 programs managed by JAEA and carried-out by NNC-RK, and the PLINIUS-2 test program,oThe Fuel Coolant Interaction and the associated PLINIUS-2 test program.

Domaines: Physique Nucléaire Expérimentale [nucl-ex]; Physique Nucléaire Théorique [nucl-th]

F. Serre, F. Payot, C. Suteau, L. Trotignon, E. Batyrbekov, et al.. R&D and Experimental Programs to support the ASTRID Core Assessment in Severe Accidents Conditions. ICAPP 2016 - 2016 International Congress on Advances in Nuclear Power Plants, Apr 2016, San Franscisco, United States. ⟨cea-02509785⟩