chemical formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...
secondary
Secondary may refer to: Science and nature
* Secondary emission, of particles
** Secondary electrons, electrons generated as ionization products
* The secondary winding, or the electrical or electronic circuit connected to the secondary winding i ...
uranium
Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...
mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ( ...
containing
peroxide
In chemistry, peroxides are a group of compounds with the structure , where R = any element. The group in a peroxide is called the peroxide group or peroxo group. The nomenclature is somewhat variable.
The most common peroxide is hydrogen p ...
formed by the
alpha
Alpha (uppercase , lowercase ; grc, ἄλφα, ''álpha'', or ell, άλφα, álfa) is the first letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician letter aleph , whic ...
-
radiolysis
Radiolysis is the dissociation of molecules by ionizing radiation. It is the cleavage of one or several chemical bonds resulting from exposure to high-energy flux. The radiation in this context is associated with ionizing radiation; radiolysis is ...
of water during formation. It occurs as pale yellow to white needle-like
crystal
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...
Shinkolobwe
Shinkolobwe, or Kasolo, or Chinkolobew, or Shainkolobwe, was a radium and uranium mine in the Haut-Katanga Province of the Democratic Republic of the Congo (DRC), located 20 km west of Likasi (formerly Jadotville), 20 km south of Kamb ...
, and has since been reported from several other localities. The mineral was named for Franz Edward Studt, an English
prospector
Prospector may refer to:
Space exploration
* Prospector (spacecraft), a planned lunar probe, canceled in 1962
* '' Lunar Prospector'', a NASA spacecraft
Trains
* Prospector (train), a passenger train operated by the Denver & Rio Grande Western ...
and
geologist
A geologist is a scientist who studies the solid, liquid, and gaseous matter that constitutes Earth and other terrestrial planets, as well as the processes that shape them. Geologists usually study geology, earth science, or geophysics, althou ...
who was working for the Belgians.
When exposed to air studtite converts over a short time to the metastudtite UO4·2(H2O) form. Despite their apparent chemical simplicity, these two uranyl species are the only reported peroxide minerals.
They may also be readily formed on the surface of
nuclear waste
Radioactive waste is a type of hazardous waste that contains radioactive material. Radioactive waste is a result of many activities, including nuclear medicine, nuclear research, nuclear power generation, rare-earth mining, and nuclear weapons r ...
under long-term storage and have been found on the surface of spent nuclear fuel stored at the Hanford, Washington nuclear site.
* It has also been reported that studtite has since formed on the corium ''lavas'' that were created during the course of the Chernobyl nuclear plant accident. Thus, there is considerable evidence that
uranyl peroxide
Uranyl peroxide or uranium peroxide hydrate (UO4·nH2O) is a pale-yellow, soluble peroxide of uranium. It is found to be present at one stage of the enriched uranium fuel cycle and in yellowcake prepared via the ''in situ'' leaching and resin ion e ...
s such as studtite and metastudtite will be important alteration phases of
nuclear waste
Radioactive waste is a type of hazardous waste that contains radioactive material. Radioactive waste is a result of many activities, including nuclear medicine, nuclear research, nuclear power generation, rare-earth mining, and nuclear weapons r ...
, possibly at the expense of other minerals, such as uranyl oxides and
silicates
In chemistry, a silicate is any member of a family of polyatomic anions consisting of silicon and oxygen, usually with the general formula , where . The family includes orthosilicate (), metasilicate (), and pyrosilicate (, ). The name is al ...
, which have been more thoroughly studied and are better understood. The formation of these minerals may impact the long-term performance of
deep geological repository
A deep geological repository is a way of storing hazardous or radioactive waste within a stable geologic environment (typically 200–1000 m deep). It entails a combination of waste form, waste package, engineered seals and geology that is suited ...
sites such as
Yucca Mountain nuclear waste repository
The Yucca Mountain Nuclear Waste Repository, as designated by the Nuclear Waste Policy Act amendments of 1987, is a proposed deep geological repository storage facility within Yucca Mountain for spent nuclear fuel and other high-level radio ...
. Due to insufficient information about these minerals it is unknown if they will make
radioactive waste
Radioactive waste is a type of hazardous waste that contains radioactive material. Radioactive waste is a result of many activities, including nuclear medicine, nuclear research, nuclear power generation, rare-earth mining, and nuclear weapons r ...
s more or less stable, but the presence of studtite and metastudtite provides a pathway for mobilizing insoluble U(IV) from the corroding fuel surface into soluble
uranyl
The uranyl ion is an oxycation of uranium in the oxidation state +6, with the chemical formula . It has a linear structure with short U–O bonds, indicative of the presence of multiple bonds between uranium and oxygen. Four or more ligands may ...