This year, the MARIA reactor is celebrating its 50th anniversary. It is the only operating nuclear reactor in Poland and plays a key role in scientific research, medicine and industry. 

History and design of the MARIA reactor 

Construction of the reactor began in June 1970, and it first reached criticality on December 18, 1974. The name of the reactor commemorates Marie Sklodowska-Curie, a pioneering researcher of radioactivity. MARIA was designed and built by Polish specialists as a multipurpose reactor with high neutron flux, with a view to conducting materials research and supporting nuclear power plant construction and operation programs. 

Reactor functions and applications 

The MARIA reactor does not produce electricity; its main function is to generate a strong neutron flux. This enables the production of radioisotopes used in medicine, industry and environmental protection. The most important isotopes produced at the reactor include molybdenum-99, iodine-131, lutetium-177, phosphorus-32, samarium-153, cobalt-60 and holmium-166, and are exported under the POLATOM brand to more than 80 countries around the world. 

MARIA is one of the key suppliers of molybdenum-99, used in cancer diagnostics and therapy. It also covers a significant portion of the world’s demand for iodine-131, used in the diagnosis and treatment of thyroid diseases. Through its work, the reactor contributes to saving the lives of hundreds of thousands of people around the world. 

Upgrades and the future of the reactor 

Since its startup, the reactor has undergone numerous upgrades, including a switch from highly enriched to low-enriched fuel, which has made its operation safer. Currently, the fuel’s uranium-235 content is 19.75%. With ongoing improvements, MARIA remains one of the most modern research reactors and plans to continue operation until at least the 1950s of the 21st century. 

The MARIA reactor also plays an important role in training new employees for the nuclear industry. It provides training and research for students and specialists in various fields of science and technology, which contributes to the development of Poland’s nuclear power potential. 

On the occasion of the 50th anniversary of the MARIA reactor, the National Center for Nuclear Research has prepared a special website where you can learn about the history and achievements of this unique facility: https://50latmarii.ncbj.gov.pl 

We invite you to watch the Symposium “The 50th anniversary of the MARIA reactor” held by NCBJ on October 25, 2024: https://www.youtube.com/live/AFUB5NbroLE?si=OJFxu7ZaOQTBT0Sj 

Sources / photos: National Center for Nuclear Research