On 23 June, a joint laboratory memorial seminar “60 anniversary of the IBR reactor start-up” was held in the Laboratory of Neutron Physics. The seminar took place in the Conference Hall of the Laboratory in a video conference format.

FLNP Director V. N. Shvetsov opened the event with a brief historical overview. He began his speech with congratulations to Bulgarian colleagues cooperation with whom had been ongoing for many years. Director of the Institute of Electronics of the Bulgarian Academy of Sciences Professor P. Petrov congratulated employees of the Laboratory on the glorious date and wished them new high scientific achievements.

On 23 June 1960, 60 years ago, the first pulsed reactor of FLNP reached the pulse criticality and a corresponding historic record was made in the laboratory journal certified with signatures of all participants of the power start-up. The IBR reactor launched the dynasty of JINR pulsed reactors that was continued later by the IBR-30 and the IBR-2. But just five years before this event, D. I. Blokhintsev first proposed the idea of a pulsed reactor at a seminar in the Institute of Physics and Power Engineering (IPPE), Obninsk. Just in a year, in 1956, the theory of pulsed reactors was developed by I. I. Bondarenko and Yu. Ya. Stavissky. The construction of the future reactor started simultaneously with the creation of the theory. “I do not really know, especially in view of modern realities, how this was possible,” Valery Nikolaevich commented on this fact. As a result of this fascinating activity, the facility was launched in two years. “I congratulate everyone on this significant date. God willing, we will create another machine that will work for a long time.”

Then Yu. N. Pepelyshev presented the concept of the fast pulsed reactor of periodic operation developing ideas laid in the IBR-2 basis (co-authored with A. Having thanked the speaker, V. Vinogradov, A. D. Rogov, S. F. Sidorkin). The authors assume that it will be possible to reduce the volume of development activities as much as possible and to use successful developments. Thus, when creating the IBR-2 reactor, specialists used the experience in the design of the IPPE BR-5 reactor. It is proposed to take into account technical solutions used at the modernized IBR-2, BR-60 and MBIR reactors when developing the new facility. The main difference from the IBR-2 is that reactor control and protection systems will be placed inside the core as it is done in BOR-60, MBIR and BN-600. This will allow bringing neutron moderators closer to the reactor’s body and raise the protection level. Another advantage of the project is that it is possible to use the reactivity module developed for the modernized IBR-2 and a number of its spectrometers.

The report evoked numerous questions that resulted in the discussion in the hall and on the internet. Having thanked the speaker, V. N. Shvetsov noted that this presentation did not mean that FLNP had not decided upon the project of the new neutron source. “The choice has been done, but we are in for a challenging way, and we may return to this variant at any time. However, we cannot afford to subject each newly developed variant to long and expensive testing in NIKIET. But this project has valuable research.”

At the end of the seminar, its participants received by phone congratulations on the jubilee from a participant of the creation and start-up of the IBR E. P. Shabalin who was not present at the seminar.

Olga Tarantina, JINR Weekly Newspaper
Photos by Igor Lapenko