Professor Roman Żelazny was born on 4^th December 1926 in Kielce.

He started his scientific career from studying on the Faculty of Aircraft Engines, Łódź University of Technology. Already during his studies, as a recognition of his skills, he worked as an assistant with students from lower years.

After his studies he becomes an assistant in Warsaw University of Technology, but his talents in mathematics and fondness for theory leads him in 1954 to University of Warsaw, where for two years he catches up missing lectures from University of Technology. Then, he begins working in the group of Professor Leopold Infeld, a collaborator of Einstein and co-creator of Institute for Theoretical Physics of University of Warsaw.

Then, directed to Dubna, he works there on a six moth internship in Laboratory of Theoretical Physics of Professor M. Bogoliubow, and, after return, he finishes doctoral studies in 1958.

Further course of Professor’s scientific development is an internship in USA (1961–62) in Case Institute of Technology with Professor Kenneth F. Case. After coming back to the country he develops methods of analytical solutions of transport equations, which he learned in USA, and applies them to neutron and plasma problems. The result of a number of publications in this field is his habilitation in 1963. From this moment Professor Żelazny showcases his skills as an organiser. He gathers a group of talented young scientists around him (Roman Bednarz, Antoni Kuszel, Janusz Mika) and, in 1964, people start talking about „polish school of neutron transport”. This results in scientific cooperation with many institutions, including group of Professor Ilya Prigogine from Universite Libre in Brussels.

Being so successful with theoretical problems, Professor Żelazny already notices the importance of computers in physics and in 1965, as a result of his efforts, the Institute for Nuclear Research in Świerk becomes home to Danish GIER binary machine, with incomprehensible parameters for today – 1 thousand words of fast memory, 16 thousand words of magnetic memory and speed of 20 thousand arithmetic operations per second. On this computer, project calculations for the core of Maria reactor were conducted.

In 1965 Professor Żelazny receives the title of Associate Professor. At the time he’s 38 years old.

Already in 1968 it was evident, that GIER cannot cope with the needs of Institute for Nuclear Research and associated institutions. Efforts for a new computer begin. After year 1970 some things are made possible and the CYBER 72 computer is chosen. It is an upgraded version of CDC 6600 computers, that were used by Americans to send a man to the Moon. However, the purchase was under condition of breaking the USA embargo for devices classified as strategic. Today it seems easy, but at that time it was not. We have gotten a permission for purchase from USA, but under condition, that the computer would be frequently inspected by the Americans, which in turn required to break the local reluctance. This was achieved and in 1973 CYBER 72 was placed in Świerk in the CYFRONET computing centre, that was led by Professor Żelazny. The institute employed about 100 people, both with Reactor Computing Division. Continuing the good organizational streak, Professor Żelazny was appointed as Deputy Director for Physics of Institute for Nuclear Research.

In 1983 the IBJ was divided into 3 parts, among other things, the Institute for Atomic Energy (IEA) was created. Professor Żelazny was bac in CYFRONET. When, at the end of the 80 s in the Institute there was created, essentially only as a „decoration”, Workers Board, Professor didn’t hesitate to candidate and became its Chairman, despite his scientific position. Because of this, IEA Workers Board was a counterweight to Institute’s Management Team.

Common trust, which Professor Żelazny was given at the time resulted in, upon application from „Solidarność” in Świerk, appointing him to the position of Chairman of National Atomics Agency (PAA) by Prime Minister Mazowiecki. He held this position in the years 1989–91. He devoted much of his energy to continute the construction of Żarnowiec Nuclear Power Plant. The result of his work in PAA is signing Poland’s membership agreement with CERN.

After finishing his work in PAA Professor Żelazny returned to science and worked in Institute for Plasma and Laster Microsynthesis, because he was acquainted with plasma physics while already working in IEA. This period was fruitful in papers for, among other things, JET installation (Joint European Torus) touching on flow analyses in equilibrium states in tokamak, especially using numerical solution of Grad-Shafranov equation.

At the same time, he did not lose touch with IEA (then with NCBJ) thanks to cooperation with team of Dr M. Borysiewicz, which participated in many EU projects dedicated to developing the RODOS system (Real-time On-line Decision Support System). The aim of this system of computer programmes is aiding in making decisions regarding civil protection after a nuclear accident. Scientists working for this project were improving techniques of modelling weather events and deposition of pollution on atmosphere. Professor was aslo involved in creation of Excellence Centre MANHAZ (Management of Health and Environmental Hazard), led by Dr M. Borysiewicz and Dr S Potempskiego. The centre carried the methods and procedures undertaken in an event of nuclear accident onto conventional accidents, for example chemical installations.

During this period, Professor also cooperated with Geophysics Institute of University of Warsaw, for example participating in the project Metodyka generacji regionalnych bred wektorów dla obszaru Polski dla potrzeb prognozowania pogody metodą wiązek”.

Professor Żelazny passed away on 31^st October 2018.

It is hard to describe, in a short memoir, rich personality of Professor Żelazny, scientist, organizer, social activist.

We will miss his courage in undertaking new challenges, care for development of young generation of scientists and respect for all co-workers.