BAGIRA

BAGIRA4 – Reactor irradiation loop

Instrument responsible: Attila Kovács, Ferenc Gillemot, Ákos Horváth

At the Budapest Research Reactor, two gas cooled irradiation rigs (BAGIRA 1, 2 and 3) have been operated since 1998. Twenty seven different irradiation researches have been performed, testing irradiation ageing of reactor and fusion devices, structural materials, as low alloyed and stainless steels, Al, Ti and W alloys, ceramics etc. The devices served more than 17 years. The material aged by irradiation and corrosion, and their capacity cannot satisfy the up-to date requirements of the newly developing materials.

Presently the main  interest of the nuclear industry is the development of fusion reactors and Generation IV reactors. To increase the efficiencey and decreasse the impact on the environment, high operation temperature will be used. Consequently high temperature irradiation combined with in pile creep and fatigue testing are the future tasks of the irradiation devices.

Nowadays, there are only a few research reactors in Europe. With the new device in connection with the hot laboratory and with the existing know-how,   we are capable of participating in international research projects, as well as customized irradiation and post irradiation examination in cooperation with several institutes and nuclear power industries worldwide.    

Description of the new device

The new device is called Budapest Advanced Gas-cooled Irradiation Rig with Aluminium structure 4, BAGIRA4.

The main features of it are:

- The rig capacity is 24 Charpy size specimen (appr. 800 gr steel) or similar. The specimen sizes and shape can be varied according to the requirements, since only the target simple holder has to be changed.

BAGIRA

Figure 1. :Fully filled target, with 6 adjustable thermal control zone

- At each of the new six zones, the electric heating can be separately controlled, ensuring to keep the required irradiation temperature within ±5°C. Irradiation temperature can be controlled between 150°-350°C with gamma and electric heating and helium-nitrogen gas mix cooling.

- The maximum fluence rate is 3*1013 n/cm2 E>1MeV (approximately 1,5 dpa/year).

- The target holder is separated from the thermocouples and electric heating system. This way the cost of the heating elements and thermocouples decreasing, and only minor quantity of aluminium or titanium heat removal material goes into the radioactive waste.

The new target pick up and eject system allows the quick target change during the operation pause of the reactor , and active target also can be used (e.g. irradiated and annealed material can be reirradiated)

Bagira2

Figure 2.: Assembled Bagira4 head with gas and electrical connectors

The device is designed for automatic operation, programmable, and it has several safety features, (including emergency passive cooling system, automatic reset in case of any malfunction of the control system, etc.)

The present situation and the remaining work

The equipment is ready and the control software is tested several hundred hours. Twelve different safety tests performed successfully, and the Hungarian National Safety Authority permitted the installation into the reactor.

From the second half of 2016 some functional materials: Spinel, Alumina, Diamond, YAG will be irradiated in the Bagira 4, under the Functional Materials (FM) subproject of European Consortium for the Development of Fusion Energy (Eurofusion).

References

Gillemot Ferenc: „Study of Irradiation Effects at the Research Reactor” Strengths of materials, Vol 42. No 1. 2010, Springer Science pp.78-83