Speaker
Description
One of the four breeding blanket candidates as options for European DEMO nuclear fusion reactor is the Water Coolant Lithium Lead Breeding Blanket (WCLL BB). The WCLL in-box LOCA (Loss of Coolant Accident) is a major safety concern of this component, therefore transient behavior will be investigated to support the design, to evaluate the consequences and to adopt mitigating countermeasures. This requires the availability of a predictive tool code capable to simulate the safety related phenomena and parameters occurring during the transient. To fulfill this objective, at the beginning step, SIMMER-III code was improved implementing the chemical reaction between PbLi and water. Then, SIMMER-III Verification and Validation (V&V) procedures have been established and conducted to obtain a qualified code for deterministic safety analysis. The verification activity was successfully completed, while the validation activity requires further efforts according with the R&D plan set up in the framework of the EUROfusion Project. In view of this, an experimental campaign and a test matrix has been designed in LIFUS5/Mod3 facility.
The experimental data of the Test D1.1 which are obtained from the mentioned facility are used for the validation SIMMER-III according with a standard procedure. This is based on a three-steps involving the qualitative and quantitative evaluations of code results. The qualitative accuracy evaluation is performed through a systematic comparison between experimental and calculated time trends based on the engineering analysis, the resulting sequence of main events, the identification of phenomenological windows and aspects relevant to safety. Finally, the accuracy of the code prediction is evaluated from quantitative point of view by means of selected figures of merit.
