Fusion Engineering and Design 51–52 (2000) 611–616 Modelling of the Pb17Li/water interaction within a blanket module P. Sardain a, *, G. Benamati b , I. Ricapito b , G. Marbach a a CEA-DRN/DER Cadarache, 13108 St. Paul lez Durance Cedex, France b ENEA, Diisione Fusione Brasimone, Italy Abstract In the frame of the WCLL (water cooled lithium lead) programme, experimental and theoretical activities are devoted to study the interaction between the cooling water and lithium lead alloy. In case of large leakage, the interaction can lead to a pressurisation of a blanket module which can challenge its integrity. Therefore, it is important to assess its consequences as accurately as possible. In order to make possible the modelling of the next LIFUS 5 experimental activity and to correctly understand the phenomena connected to a large break LOCA (loss of coolant accident) in the breeder zone in real conditions, a mathematical model has been tested on the BLAST experiences carried out at JRC-Ispra in the past years. A good fitting between experimental and modelling results has been obtained as shown in this paper. © 2000 Elsevier Science B.V. All rights reserved. Keywords: Pressure; BLAST; Alloy www.elsevier.com/locate/fusengdes 1. Introduction Although in the reference design of the WCLL (water cooled lithium lead) blanket for DEMO double wall cooling tubes have been envisaged, a possible interaction between cooling water and lithium lead eutectic alloy still remains one of the biggest concerns for this concept. From the point of view of the characteristics of the interaction, it is convenient to consider two types of events: small leakage as a result of micro-cracks and large leakage following for example a cooling tube rup- ture. The two events are generally linked since the occurrence of a large leakage is often the effect of the development over time of a micro-crack (Fig. 1). Concerning the R&D activities devoted to large water-steam LOCA in the breeder zone, a new apparatus LIFUS 5 has been constructed and is now ready for operation at the ENEA Centre of Brasimone. With LIFUS 5 experimental cam- paigns of BLAST facility [1,2] will be continued using a different geometry and operative condi- tions closer to the real ones. At the same time a modelling activity is under development to simulate pressure evolution in LIFUS 5 with the aim of making possible a reliable scaling-up to the actual blanket module design for DEMO. BLAST experiments are taken * Corresponding author. E-mail address: sard@buffet.cad.cea.fr (P. Sardain). 0920-3796/00/$ - see front matter © 2000 Elsevier Science B.V. All rights reserved. PII:S0920-3796(00)00252-0