Page 135 - Thermal Hydraulics Aspects of Liquid Metal Cooled Nuclear Reactors

108 Thermal Hydraulics Aspects of Liquid Metal Cooled Nuclear Reactors

Fig. 3.3.1 Overview of experimental liquid-metal facilities at KIT.

3.3.1.1 General characteristics defining an experimental liquid
(metal) facility

Beyond some special features depending on the application, the following character-
istics, common to all facilities listed in Fig. 3.3.1, lead to considerations related to the
construction:
l The existence of an inventory of liquid leads to a chemical (pre-)conditioning system.
l Inevitably, liquids are contained in vessels, leading to the industrial norms for their construc-
tion and safety approval, for example, DIN-EN-13445.
l Accounting for its weight and size, the facility must have appropriate support structures and
other related elements, such as foundation, scaffolding, and crane.
l Depending on the application, components can be classified in main and auxiliary.
l Instrumentation, complemented by a modern data acquisition system, for monitoring all
variables relevant to the operation of the facility.
l Control system, actuating on some independent variables (e.g., a valve opening fraction), to
influence on other dependent target ones (e.g., the flow rate).
l Regarding additional infrastructure, a special emphasis is given to the electric system, both
for power and signal purposes.
In principle, the above-listed features are common to all liquids. Considering water as a
standard reference, the specificfeatures of liquid metals are described in the nextsection.

3.3.1.2 Special features of liquid metals and their impact
on the facilities
Compared with other liquids such as water, the construction of a liquid-metal facility
is affected by several specific features of the fluids. Issues related to physical and
chemical properties and materials compatibility are presented below, focusing on
LBE and Na.