COMSOL Simulation for Design of Induction Heating System in VULCAN Facility

The experimental facility VULCAN was setup to study the fuel-coolant interaction (FCI) phenomena in a postulated severe accident of light water reactors. The heating system is important for the facility to prepare molten material in a crucible. This article is concerned with the design of the heating system, which applies electromagnetic induction heating method. The COMSOL code was employed to simulate the induction heating characteristics of a graphite crucible under different current and frequency of the work coil (inductor). Given a frequency, the relationship between the crucible’s average temperature and the inductor’s current is obtained, which is instrumental to select the power supply of the induction heating system. Meanwhile, the skin effect of induction heating is analyzed to guide the choice of frequency and inductor of the heating system. According to the simulation results, the induction heating system of frequency 47 kHz is suitable for the experiment, with a good agreement in temperature between the measured and the predicted.

Recent Activities and New Challenges for the EUR Organization

Since 1991, the European Utility Requirements (EUR) organization has been developing and promoting harmonized technical specifications for the new mid- and large-size LWR designs to be proposed by the vendors in Europe. The EUR Organization issues and, from time to time, modifies and updates a report entitled “the EUR Document”. It consists of a comprehensive set of requirements covering the whole Nuclear Power Plant (NPP) and encompasses all aspects (safety, performance, competitiveness) and all parts of a NPP (nuclear island and conventional island). The main EUR Organization’s results obtained during the last years are in the three following fields: (1) The latest revision, Revision E, of the EUR Document was issued in December 2016. It includes revised safety requirements taking into account the most recent European and international standards issued by WENRA, IAEA and IEC after the Fukushima-Daishi accident. (2) The assessment of new designs. The presentation briefly recalls the EUR design assessment objectives and process and the status of the different EUR assessment projects. (3) Preparation of evolution of the EUR Document towards integration of requirements for Small Modular Light Water Reactors (SMLWR). The paper concludes by an overview of the future activities of the EUR Organization.

Hydrogen Atom and Molecule Adsorptions on FeCrAl (100) Surface: A First-Principle Study

FeCrAl alloys are promising accident-tolerant fuel (ATF) cladding materials for applications in light water reactors (LWRs). Despite the excellent mechanical and antioxidation properties, this series of iron-based alloys has poor hydrogen embrittlement (HE) resistance due to the strong hydrogen uptaking ability. The hydrogen embrittlement effect can cause the degradation and premature failure of the material, and this effect can be enhanced by the high-temperature/high-pressure/high-irradiation environment in reactors. So, the potential danger should be taken seriously. In this paper, we have studied the hydrogen atom and molecule adsorptions on both Fe (100) and FeCrAl (100) surfaces to discover how the hydrogen atom and molecule (H/H2) interact with the Fe and FeCrAl (100) surface in the first place. The results show that there are strong element effects on the FeCrAl surface. The Al atom itself has no interaction with hydrogen. When the Al atom is beside the Fe atom, this Fe atom has a slightly lower interaction with hydrogen. However, the Al atom beside the Cr atom will enhance the hydrogen interaction with this Cr atom. On the other hand, when the Cr atom is beside the Fe atom, these two atoms (Fe–Cr bridge site) can reduce the interactions with H. In addition, when two Cr and two Fe atoms together make a four-fold site (FF site), the two Cr atoms can increase the interaction of the two Fe atoms with H. The element effects discovered can be a good guide for making hydrogen prevention coatings.