We regret to inform you that on 11.09.2021 the following passed away after a long illness at the age of 91
Jerzy Kubowski, Ph.D., a long-time employee of the A. Soltan Nuclear Research Institute.

Dr Kubowski was involved in the problems of reactor physics and safety. He served at the IEA, among others, as Head of the Reactor Analysis and Measurements Department and as Chairman of the Nuclear Safety and Radiation Protection Commission.

It is also with deep regret that we bid farewell to Dr Kubowski's wife Mrs Etelka Sallay-Kubowska, who died on 13.09.2021.

The funeral ceremony will take place at the funeral home in the Military Cemetery on
16.09.2021 at 1.00 p.m. A spousal farewell will be held at the same time and place.

We were saddened to learn of the death of Dr Jerzy Kubowski. The rhythm of life and death has once again shown its inevitable face. Today we bid farewell to another former employee of the Atomic Energy Institutes, who had been associated with the Świerk Centre since the 1960s. We bid farewell to a man of great knowledge, great professional competence and great experience, and a person with intellectual horizons that went far beyond the realm of his profession.

Mr Jerzy Kubowski has spent his professional life in the broad field of nuclear energy. When he started his work at the Department of Reactor Physics of the then Nuclear Research Institute, he dealt with various aspects of nuclear facility safety, including the EWA and MARIA reactors operated at the Świerk Centre. Launched in the 1970s, the MARIA reactor not only became a tool for the implementation of research programmes using the capabilities of the high flux reactor, it also required a number of analyses, measurements, tests. In addition to issues of reactor physics, in which he obtained a PhD, he also worked on thermal-fluid analyses and adapted the ORIGEN computational code effectively used in the MARIA reactor. This work resulted in successive editions of the Safety Report, which were written under the editorship of Jerzy Kubowski, Ph.D., with the participation of the Reactor Measurements and Analyses Laboratory team he created.

A high level of expertise and the ability to bring together a group of enthusiasts around new projects allowed activities to be initiated, resulting in new analytical and measurement tools. Personally, I can mention with satisfaction the work on self-powered detectors, the first work using an analyser with a germanium detector, the work using the first personal computers. The doctor, being my first supervisor, was at the same time a great mentor, discussant, a person enabling me to realise my research plans.

We bid farewell to one of the last people who are the history of Polish research reactors. Our younger colleagues, despite the fact that they did not have the opportunity to meet Jerzy Kubowski directly, still make use of his scripts and papers, which are still a source of basic knowledge for the MARIA reactor operating staff. The script "Fundamentals of Reactor Physics" can be found today on the desks of future reactor operators.

It is impossible not to mention one more passion of Jerzy Kubowski. It was educational activities. He is the author of a number of books on various aspects of reactor technology and nuclear safety. These publications are an important voice in the discussion on nuclear energy. Among these items one can find such titles as: "Nuclear Power Plants", "The Chernobyl Disaster", "Nuclear Weapons" or "The History of the Atomic Bomb".

Farewell to Mr Kubowski, farewell to Mr Jerzy.

Janusz Jaroszewicz