• ENEA
• in-box-LOCA
• ITER
• DEMO
• LIFUS5MOD4
• PbLi

In the context of the advanced design of the European DEMO nuclear fusion reactor, the Water Cooled Lithium Lead (WCLL) configuration is proposed as a leading possibility for the Breeding Blanket technology and, on this basis, it has been recently confirmed to be part of the ITER Test Blanket Module (TBM) program.
The Test Blanket Module Program aims at providing the first experimental data on the performance of the breeding blankets in the integrated fusion nuclear environment, in order to assist the development of fully functional fusion reactors, such as DEMO. The program foresees to test four mock-up breeding blanket technologies in proper test boxes, called Test Blanket Module, in two dedicated ITER equatorial ports from the beginning of the ITER operation. The Test Blanket Module and its associated ancillary systems, including cooling system and tritium extraction system, forms the Test Blanket System that will be fully integrated in the ITER machine and buildings.
The WCLL BB design involves the use of liquid Lithium-Lead as breeder, neutron multiplier and tritium carrier, and water as coolant, at Pressurized Water Reactor conditions. Consequently, a critical safety issue of the WCLL configuration is the possible interaction between PbLi and water caused by a tube rupture in the breeding zone, namely an in-box LOCA (Loss of Coolant Accident) scenario. The potential evolution of this kind of scenario must be carefully evaluated through the collection and analysis of experimental data, which must be also used to support the development of a qualified system code for deterministic safety analysis; a reliable code is indeed needed for the assessment of the accidental consequences and to propose possible mitigating countermeasures, and furthermore to suggest design solutions for the prevention of severe damages to the structures involved. Following these objectives, ENEA designed and built a separate effect test facility named LIFUS5/Mod3 and conducted two experimental campaigns by injecting water at high pressure into a pool of PbLi, in WCLL-BB relevant parameter ranges. A new LIFUS5/Mod4 Integral Test Facility (ITF) is under design, and it will be constructed at ENEA CR Brasimone. The facility will be a full-scale representation of the WCLL TBM PbLi loop and it will be paired with the Water Loop (WL) facility, a full-scale model of the WCLL TBS Water Cooling System (WCS). The objective of the experimental campaign is to investigate the phenomenology, the behaviour, and the response of the WCLL Test Blanket Systems under in-box LOCA at integral levels and in relevant operative conditions. Moreover, the facility will be able to reproduce and assess the effectiveness of the safety functions and procedures implemented in such scenarios. This involves continuing the validation activity on the code-coupling and the procedure for its application, together with the validation of SIMMER against ITF experiments.