The Maria reactor is

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populous ...

's second

nuclear research reactor Research reactors are nuclear fission-based nuclear reactors that serve primarily as a neutron source. They are also called non-power reactors, in contrast to power reactors that are used for electricity production, heat generation, or mariti ...

and is the only one still in use. It is located at Narodowe Centrum Badań Jądrowych (NCBJ) (National Center for Nuclear Research) at Świerk-

Otwock Otwock is a city in east-central Poland, some southeast of Warsaw, with 44,635 inhabitants (2019). Otwock is a part of the Warsaw Agglomeration. It is situated on the right bank of Vistula River below the mouth of Swider River. Otwock is hom ...

, near Warsaw and named in honor of

Maria Skłodowska-Curie Marie Salomea Skłodowska–Curie ( , , ; born Maria Salomea Skłodowska, ; 7 November 1867 – 4 July 1934) was a Polish and naturalized-French physicist and chemist who conducted pioneering research on radioactivity. She was the first ...

. It is the only reactor of Polish design. Maria is a multifunctional research tool, with a notable application in production of

radioisotope A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...

s, research with utilization of neutron beams,

neutron therapy Fast neutron therapy utilizes high energy neutrons typically between 50 and 70 MeV to treat cancer. Most fast neutron therapy beams are produced by reactors, cyclotrons (d+Be) and linear accelerators. Neutron therapy is currently available in ...

, and

neutron activation analysis Neutron activation analysis (NAA) is the nuclear process used for determining the concentrations of elements in many materials. NAA allows discrete sampling of elements as it disregards the chemical form of a sample, and focuses solely on atomic ...

. It operates about 4000 hours annually, usually in blocks of 100 hours.

Technical description

The technical details of the reactor are given in the references. Maria is a pool type reactor with a power of 30 MW (thermal). Despite it being a pool reactor, it contains channels (aluminum tubes) individually connected to the primary coolant. The water pool provides cooling for elements (e.g., fuel elements) that are not otherwise cooled, and also acts as radiation shielding. Maria uses

enriched uranium Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written 235U) has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes: uranium-238 (238U ...

as fuel (80% enrichment in ²³⁵U till year 1999; 36% since). The fuel elements and channels are vertical but arranged conically. Water and

beryllium Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to form mi ...

blocks serve as the moderator (70% and 30% of the moderation, respectively). Elements of

boron carbide Boron carbide (chemical formula approximately B4C) is an extremely hard boron–carbon ceramic, a covalent material used in tank armor, bulletproof vests, engine sabotage powders, as well as numerous industrial applications. With a Vickers hard ...

sheathed in aluminum are utilized for control, compensation, and safety. The use of beryllium blocks results in a comparatively large fuel lattice pitch, and consequently large volume for payload targets. There is also a

graphite Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on large ...

reflector (aluminum sheathed). Maria supplies a

neutron flux The neutron flux, φ, is a scalar quantity used in nuclear physics and nuclear reactor physics. It is the total length travelled by all free neutrons per unit time and volume. Equivalently, it can be defined as the number of neutrons travellin ...

of 4x10¹⁴ n/cm²s (

thermal neutrons The neutron detection temperature, also called the neutron energy, indicates a free neutron's kinetic energy, usually given in electron volts. The term ''temperature'' is used, since hot, thermal and cold neutrons are moderated in a medium with ...

) and 2x10¹⁴ n/cm²s (

fast neutrons The neutron detection temperature, also called the neutron energy, indicates a free neutron's kinetic energy, usually given in electron volts. The term ''temperature'' is used, since hot, thermal and cold neutrons are moderated in a medium with ...

). There are six horizontal channels for controlled use of neutron beams. There is also a window of lead-containing glass through which the core can be viewed. The reactor is housed in a sealed containment. Following preparation which started in 2004, Maria was converted to use

low-enriched uranium Enriched uranium is a type of uranium in which the percent composition of uranium-235 (written 235U) has been increased through the process of isotope separation. Naturally occurring uranium is composed of three major isotopes: uranium-238 (23 ...

(LEU) fuel by 2012.

History

Construction began on June 16, 1970 and the reactor was activated on December 18, 1974. With the shutdown of the

Ewa reactor The Ewa Reactor was Poland's first research nuclear reactor. Its name was derived from the first letters of the Polish words: ''Eksperymentalny'' (Experimental), ''Wodny'' (Water), and ''Atomowy'' (Atomic) as a reference to Ève Curie. History T ...

in 1995 it became Poland's only research nuclear reactor. In 2015, Maria was relicensed for an additional 10 years of operation, through 2025.

Production of medical radioisotopes

In February 2010, it was announced that Maria will start producing

medical isotopes A medical isotope is an isotope used in medicine. The first uses of isotopes in medicine were in radiopharmaceuticals, and this is still the most common use. However more recently, separated stable isotopes have also come into use. Examples of ...

in cooperation with Covidien, to help ease the isotope shortages due to shutdowns of the Canadian NRU reactor and the Dutch

Petten nuclear reactor The Petten High Flux Reactor (HFR), is a nuclear research reactor located in Petten, The Netherlands. The HFR is on the premises of the Petten research centre and it is a high flux reactor. It is owned by the Joint Research Centre (JRC) and manage ...

.Matthew Wald, "Poland emerges as new source of rare medical isotope",

International Herald Tribune The ''International Herald Tribune'' (''IHT'') was a daily English-language newspaper published in Paris, France for international English-speaking readers. It had the aim of becoming "the world's first global newspaper" and could fairly be said ...

, 2010-02-18, p.

/ref>

References

{{DEFAULTSORT:Maria Reactor Nuclear research reactors Nuclear research institutes Research institutes in Poland Neutron facilities

External links

* https://www.ncbj.gov.pl/en

Technical description

History

Production of medical radioisotopes

See also

References

External links