Speaker
Marica Eboli
(DICI)
Description
The interaction between lithium-lead and water is a major concern of Water Coolant Lithium Lead (WCLL) breeding blanket design concept, therefore deterministic safety analysis of the in-box LOCA postulated accident is of primary importance. In this framework, a past experimental campaign was carried out in LIFUS5 to investigate the evolution and the consequences of the interaction. Then, these data were used for evaluating the predictive capabilities of codes. No code was found able to simulate these experiments, which consider both the thermodynamic liquid metal-water interaction and the exothermic chemical reaction, including the evaluation of the hydrogen production, without engineering assumptions. This would imply that only conservative bounding analyses would be possible for the in-box LOCA, resulting in unrealistic predictions of the accident scenarios and in an excess of conservativism in the system design. In view of these considerations, a modified version of SIMMER-III code (Ver.3F Mod0.0) has been set up and is under validation at UNIPI/ENEA. The paper presents the post-test analyses by SIMMER-III Ver.3F Mod0.0 of LIFUS5 Test #3 experiment carried out in the framework of the EUROfusion Project. A series of sensitivity analyses are performed to overcome uncertainties in the test data and experiment execution, and to investigate the capability of the code in predicting both thermodynamic and chemical phenomena and processes occurring during PbLi/water interaction. Pressure trends, temperature evolutions and injected mass flow rate are compared and reported. Results show agreement between numerical results and experimental data in the long term. Besides, the predicted pressure trend bounds the experimental trends (i.e. conservative results), differences are observed in the first second of the transient due challenges in mastering the complex multi-field multi-fluid phenomena occurring during the injection. Limits of simulation due to imperfect knowledge of thermo-physical proprieties of the chemical reaction products are also pointed out.
Co-authors
Alessandro Del Nevo
(ENEA FSN-ING-PAN, ENEA Brasimone, 40032 Camugnano (BO), Italy)
Maria Teresa Porfiri
(ENEA FSN-FUSTEC-TEN, ENEA Frascati, via E. Fermi, 45 - 00044 Frascati, Italy)
Marica Eboli
(DICI, University of Pisa, Largo Lucio Lazzarino, 2 - 56122 Pisa, Italy)
Nicola Forgione
(DICI, University of Pisa, Largo Lucio Lazzarino, 2 - 56122 Pisa, Italy)
