The Institute for Nuclear Research Pitesti was founded in 1971 as a unit of strategic importance, having as field of activity the scientific research, design, technological development and scientific and technical responsibility for the development of nuclear energy in Romania.

Passive Containment Cooling System (PCCS) removes residual heat from upper drywell of the containment to the liquid pool surrounding the PCCS heat exchanger. It also has an important role in mitigating the offsite dose by retention of a fission product release in the containment. The operation of the PCCS is based on density differences between the containment and water pool

FARO (Furnace And Release Oven) experimental facility began the experiments of the LWR-MFCI phenomena in 1990 in collaboration with several reactor safety research organizations from European Union member countries and with the participation of the United States Nuclear Regulatory Commission.

Launched in 2007, the "Debris bed reflooding" (ex-PEARL) experimental research program aims to better understand the behaviour of steam and water flow in a porous medium composed of solid particles at very high temperature under conditions representative of a core melt accident (or severe accident). Experiments are conducted using the PRELUDE and PEARL test facilities of the IRSN's THEMA platform.

The PREMIX experiments have been performed to study the premixing of sizable amounts of very hot oxidic melts with water when being released as a jet in a reasonably characterized way and with full optical access. Alumina at 2600 K from a thermite reaction was used to simulate the corium melt. A technique has been developed to retain the molten iron in the source so that the contribution of iron to the melt is well below 10 %. PREMIX involves the full physics of the mixing process including jet break-up and melt drop fragmentation. But, of course, on the other hand, the initial and boundary conditions are more difficult to control and to vary compared to experiments with solid spheres such as QUEOS.

Two-phase flow test facility was constructed to study the applicability of Particle Image Velocimetry (PIV) and Wire-Mesh Sensors (WMS) for different types of single- and two-phase flows

The ARISG-I was developed to estimate the aerosol deposition in the near-field of tube breach under dry conditions. It was based on ‘filter concept’, which means that aerosol flowing through a bundle of obstacles is submitted to forces that tend to clean up the gas by removing particles onto obstacle surfaces. Under SGTR conditions, the major deposition mechanisms in the break stage are turbulent deposition and inertial impaction.

Experimental facility Figure &
A single sampler unit

The general experimental procedurewas to establish the desired composition of gases in 1-L glass flasks, optionally to add surface coupons, to irradiate the glass flasks at given dose rates until the desired doses were reached, and to subsequently determine the final air radiolysis products concentrations by an off-line method.

Facility consists of the hemispherical test vessel, a volumetric heating system in the test vessel to simulate the decay heat, a heating furnace to generate and pour the simulated corium melt, and a multitude of instrumentation to characterize the status of the melt. The test vessel is a 1:5 scaled RPV of a typical PWR with no penetrations of the lower head, and is equipped with different measurement techniques like heat flux sensors and thermocouples. The hemispherical bottom is closed by an upper lid and different openings in this upper lid allow the pour of melt to the central region or close to the perimeter of the lower head. Test vessel can be cooled by water or air at the outer surface, as it is surrounded by a second cooling vessel.

This facility comprises a water supply pipe, a quartz test section (110, 180 or 290 mm diameter) in which the debris bed is placed, together with its instrumentation, and a steam relief pipe. It is used to conduct refl ooding tests by means of injecting water onto a bed of metal particles heated by induction. The instrumentation measures the different temperatures and pressures in the debris bed, the fl ow of injected water and the fl ow of generated steam.

FARO (Furnace And Release Oven) experimental facility began the experiments of the LWR-MFCI phenomena in 1990 in collaboration with several reactor safety research organizations from European Union member countries and with the participation of the United States Nuclear Regulatory Commission.