WISE Uranium Project - HELP

Contents:

• What can I find on this site?
• Signs and Symbols used on this site
• Acronyms
• Glossary
• Unit conversion

What can I find on this site?

Major content of this site includes:

• Facts on the uranium mining and nuclear fuel industry in the world:
  • Statistics and Maps: up-to-date statistical data () and maps of the world () on many aspects of uranium and nuclear fuel - by country,

  • Deposits and Mines: detailed information on known uranium deposits and mines, including name, operational status, size, grade, economics (if available) and ownership - by country,

  • Conversion, Enrichment, and Fuel Manufacturing plants: nuclear fuel facilities - by country,

  • Companies: a list of known uranium mining and exploration companies - by name, partly with links to subsidiaries and project sites,

  • Current issues: news () concerning uranium mines (separate for planned/operating/former uranium mines, and regulatory issues), and other nuclear fuel facilities - by country: check what's going on near you, see what happens in other parts of the world; returning visitors check the latest news on the News page.
    Searches for news topics across countries are possible with the News Filter on the News page, here some example searches:
    • new in situ leach uranium mine projects
    • licensing news at any new uranium mine projects
    • opposition to any new uranium mine projects
    • indigenous peoples issues at any uranium mine/project sites
    • incidents with trade/transport of any uranium
    • incidents at any facilities
    In addition, these searches can be narrowed down to continents or countries of your choice.

  • Annual reviews of current issues and news on uranium mining (discontinued)

   

• Educational material on uranium mining, nuclear fuel production, and its impacts:
  • The Activist's Guide to Uranium Mining

  • introductory papers () on various aspects,

  • detailed texts () on uranium radiation properties, toxicity, and radiation exposure,

  • slide talks ( / ): introductory presentations on a topic, comprised of series of images, mostly with audio comment, with selectable level of detail, with automatic or manual timing,

  • online calculators (): to study
    • scientific phenomena, such as the decay and ingrowth of radionuclides in a decay series, neutron activation, alpha-neutron reactions, and the biokinetics (transport and deposition) of ingested or inhaled uranium inside the human body,
    • the material flow, energy consumption, and waste arisings of the various stages of nuclear fuel production, including also "exotic" processes, such as tails re-enrichment, and downblending of highly enriched uranium,
    • the economics of nuclear fuel production, such as feasibility of uranium mines, cost of once-through vs. recycled nuclear fuel, enrichment cost optimization, depleted uranium value realization by re-enrichment,
    and test the impacts of parameter variations.

  • Glossary

   

• Tools for the assessment of the impacts of proposed and existing uranium mines:
  • online calculators () for the assessment of
    • radiation releases from uranium mine, mill, and tailings sites,
    • resulting radiation doses for miners and residents,
    • geotechnical stability of tailings deposits,
    Where monitoring data is available for a given site, the calculators can help to evaluate the resulting health hazards. Otherwise, the calculators can model those health hazards, based on generic data, combined with site specific data, where available.

Well, quite interesting, but why does it all look so 90's?
- Quite simple: because it is 1990's!

Why isn't it suitable for use with handheld devices?
- Because they had not been invented yet in the 1990's!

Why is it all so text-heavy? Some cat pictures here and there would be nice!
- Ehm, our resident office cat hasn't given permission to use the pictures on the website 😼︎

And, why do so many pages resemble railway timetables?
- Because we do like railway timetables! 🚂︎

Signs and Symbols used on this site

External link (see disclaimer) Link opens extra page in same window Link opens new window New page or new item Page or item revised or updated Alert PDF format RSS feed German language French language English language Internal link descriptors Current Issues Introductory material Other text Data collection Map Slide Talk with audio comment Slide Talk without audio comment Calculator Link collection Bibliography Glossary

Mine and mill operating status "property"/ no information prospection/exploration ongoing prospection/exploration halted prospection/exploration finished under construction/development construction/development halted construction/development completed operating operation halted (idle) operation terminated (closed) reclamation ongoing reclamation partially completed reclamation completed   Mine and mill type   open pit mine   underground mine   in situ leaching   heap leaching   mill   tailings recovery   Project status / Issues Deposit developing , operating terminated decommissioning regulatory   Mining companies trying to acquire, or owning, uranium claim, tenement, lease, property, prospect, etc. owning uranium deposit(s) planning to develop, or developing, uranium mine(s) mining uranium   ·   big uranium miner (> 1000 t U/a) uranium mining halted   ·   no longer mining uranium

The flags used on this site are taken from Mooney's MiniFlags (created by the Flags of the World group).

ACRONYMS

ADU

ammonium diuranate

at-%

atom-percent

DOE

U.S. Department of Energy

DU

depleted uranium

EPA

U.S. Environmental Protection Agency

ESA

Euratom Supply Agency

GDP

Gaseous Diffusion Plant

GW

gigawatt (unit of power), 1 GW = 10⁹ W = 10⁶ kW = 1 million kW

GWh

gigawatt-hour (unit of energy), 1 GWh = 10⁹ Wh = 10⁶ kWh = 1 million kWh

HALEU

High Assay Low-Enriched Uranium

HEU

highly enriched uranium

HLW

High-Level Radioactive Waste

HWR

heavy water reactor

IAEA

International Atomic Energy Agency , Vienna

ISL

in-situ leaching

ISR

in-situ recovery

kerma

kinetic energy released per unit mass

kg SWU

= SWU

LEU

Low Enriched Uranium

LEU+

Low Enriched Uranium plus

LLW

Low-Level Radioactive Waste

LWR

light water reactor

MOX

mixed oxide fuel

MW

megawatt (unit of power), 1 MW = 10⁶ W = 1000 kW

MWh

megawatt-hour (unit of energy), 1 MWh = 10⁶ Wh = 1000 kWh

NEA

OECD Nuclear Energy Agency , Paris

NPT

Nuclear Non-Proliferation Treaty

NRC

U.S. Nuclear Regulatory Commission

RAR

Reasonably Assured Resources

REMIX

regenerated mixture fuel

RepU

reprocessed uranium

SWU

Separative Work Unit

t

metric tonne = 1000 kg

t SWU

= 1000 SWU

t U

metric tonne uranium contained in some compound

TRISO

Tristructural-isotropic fuel

TWh

terawatt-hour (unit of energy), 1 TWh = 10¹² Wh = 10⁹ kWh = 1 billion kWh

UF₄

uranium tetrafluoride

UF₆

uranium hexafluoride

UNH

uranyl nitrate hexahydrate

UO₂

uranium dioxide

UO₂F₂

uranyl fluoride

UO₂(NO₃)₂·6H₂O

uranyl nitrate hexahydrate

UO₃

uranium trioxide

UOC

uranium ore concentrate

U₃O₈

triuranium octoxide

wt-%

weight-percent

GLOSSARY

30B cylinder

Cylinder Model 30B for transport of enriched uranium hexafluoride (UF₆) with max. enrichment of 5.0 weight-% U-235
Nominal diameter 30 inches (76 cm), nominal length 81 inches (206 cm)
Nominal tare weight 1,400 lb (635 kg), maximum net weight 5,020 lb (2,277 kg)

48Y cylinder

Cylinder Model 48Y for transport of uranium hexafluoride (UF₆) with max. enrichment of 4.5 weight-% U-235; usually used for natural UF₆ and depleted UF₆
Nominal diameter 48 inches (122 cm), nominal length 150 inches (380 cm)
Nominal tare weight 5,200 lb (2,359 kg), maximum net weight 27,560 lb (12,501 kg)

ablation (ore)

uranium ore beneficiation process, in which high energy impact separates the mineralized patina (coating) of uranium from the underlying grain. The uranium bearing particles are found in the fine fractions separated in a subsequent screening process.

ammonium diuranate (NH₄)₂U₂O₇

original form of yellow cake

alpha-neutron (a,n) reaction

The alpha radiation from the decay of uranium sets off alpha-neutron reactions with the fluorine contained in some uranium compounds (in particular in UF₄, UF₆, and UO₂F₂), thereby generating neutron radiation from such compounds, in addition to the neutron radiation from spontaneous fission of the uranium isotope U-238.
> see also: Alpha-Neutron Reaction Calculator

alpha radiation

emission of alpha particles (2 protons and 2 neutrons); results from the alpha decay of radioactive isotopes; heavy impact on organic matter; short range only; most hazardous when incorporated

assay

concentration of an isotope (uranium isotope U-235 subsumed, if not indicated otherwise) in uranium, usually given as weight-%

beneficiation (ore)

extraction of higher grade fraction from the mined uranium ore, by physical means such as sorting or ablation; used for low-grade uranium ore to considerably reduce the amount of material that has to be processed in a uranium mill, while losing only a minor fraction of the contained uranium (view details).

beta radiation

emission of electrons; results from the beta decay of radioactive isotopes; presents limited-range external radiation exposure hazard; may cause X-ray radiation by interaction with matter (Bremsstrahlung)

blendstock

uranium (LEU, natural uranium, or DU) used for downblending of HEU

conversion

here: conversion of uranium from one chemical form into another one (usually U₃O₈ to UF₆, if not indicated otherwise); conversion of uranium ore concentrate requires a refining step first

criticality

• controlled self-sustaining chain reaction of fissile material in nuclear reactors,
• accidental uncontrolled nuclear chain reaction caused from accumulation of a critical mass of fissile material; accompanied by heavy radiation emissions (in particular neutron radiation and gamma radiation)

decay

spontaneous disintegration of a radioactive nuclide into a different nuclide (not to be confused with fission); the decay rate (described by its half-life) is specific for each nuclide; depending on the type of the decay, it is accompanied by the release of alpha, beta, and/or gamma radiation; the decay product may also be radioactive, thus forming a whole decay series
> see also: Uranium Decay Calculator · Universal Decay Calculator · Nuclear Data Viewer

de-conversion

reversal of the conversion process (usually UF₆ to U₃O₈, if not indicated otherwise)

depleted uranium (DU)

uranium (of any chemical form) with concentration of the fissile uranium isotope U-235 lower than in natural uranium (i.e. less than 0.711 weight-%) (view details ); by-product from uranium enrichment in the form of UF₆.

• short-term storage as UF₆
• de-conversion from UF₆ to U₃O₈ for shielding applications, long-term storage, or disposal
• de-conversion from UF₆ to UO₂ for MOX fuel production
• de-conversion from UF₆ to uranium metal for shielding applications, ammunition (penetrators), tank armor, and other high-density applications, or for use as irradiation target in reactors to produce plutonium
• use in various chemical forms as blendstock for HEU downblending

dilution (enriched uranium)

downblending (enriched uranium)

dilution (ore)

downblending (ore)

DN30 transport package

Cylinder Model 30B with outer "protective structural packaging", for transport of enriched uranium hexafluoride (UF₆) with max. enrichment of 5.0 weight-% U-235.

downblending (enriched uranium)

mixing of HEU with blendstock uranium, to obtain LEU for nuclear fuel (view details )
> see also: Uranium Downblending Calculator

downblending (ore)

mixing of high-grade uranium ore with low-grade material, to obtain a feed material better suitable for processing in a uranium mill
> see also: Uranium Ore Sorting Calculator

enriched uranium

uranium (of any chemical form) with concentration of the fissile uranium isotope U-235 higher than in natural uranium (i.e. greater than 0.711 weight-%) (view details ); enriched uranium presents a criticality hazard

• LEU: > 0.711 to < 20 weight-% U-235
  • LEU plus: > 5 to < 10 weight-% U-235
  • HALEU > 5 to < 20 weight-% U-235
• HEU: > 20 weight-% of U-235

enrichment

process of increasing the concentration of the fissile uranium isotope U-235 in uranium, usually by physical processes, such as gas diffusion or gas centrifugation; produces a product stream of enriched uranium and a byproduct stream of depleted uranium (tails)
> see also: Uranium Enrichment Calculator

equilibrium factor

factor describing the ratio between radon and its short-lived decay products in air (view details )

exploration

uranium exploration

feed (uranium milling)

uranium ore (as produced in a uranium mine, or after beneficiation) that is processed in a uranium mill

feed (uranium enrichment)

uranium introduced into the enrichment cascade as UF₆

• normally: natural uranium (view details )
• in the case of re-enrichment:
  • depleted uranium (DU) (view details ), or
  • reprocessed uranium (RepU) (view details )

fissile material

nuclides that can be split by induced fission (by accumulating a critical mass - intentionally in nuclear reactors and weapons, or accidentally in criticality events -, or through external neutron bombardment):

• U-235: uranium isotope contained in natural uranium (at 0.711 weight-%) and in any other uranium (at varying assays);
• U-233: artificial uranium isotope found in spent fuel and reprocessed uranium;
• Pu-239 / Pu-241: artificial plutonium isotopes extracted from spent fuel or from irradiated targets of depleted uranium metal

fission

splitting of a nuclide (not to be confused with decay); releases radiation (in particular gamma and neutron radiation) and large amounts of energy; either

• occuring as spontaneous fission (e.g. of the uranium isotope U-238), or
• induced by accumulating a critical mass of fissile material (whereby the neutrons released from spontaneous fission of the uranium isotope U-238 present in the material initiate a nuclear chain reaction), used in nuclear reactors and nuclear weapons, accidentally occurs in criticality events, or
• induced by external neutron bombardment of fissile material

gamma radiation

penetrating electromagnetic radiation; released from most alpha and beta decays; presents external radiation exposure hazard

Gaseous Diffusion Plant (GDP)

enrichment plant using the gaseous diffusion process

grade (ore)

concentration of uranium in uranium ore, given in a variety of units (e.g. weight-% U, weight-% U₃O₈, weight-ppm U₃O₈)

green salt

uranium tetrafluoride (UF₄)

half-life

measure used to describe the rate at which the decay of a radioactive nuclide occurs; it is the time period, during which half of a given amount of the specific nuclide has decayed away; it is specific for each isotope and ranges from fractions of a second to billions of years

heap leaching

method to recover uranium from low-grade uranium ore by piling the ore (mined by conventional mining techniques) after some crushing up on a heap that is percolated by a leaching liquid; the liquid is then catched at the bottom of the pile, and the uranium is recovered from the liquid in a processing plant; the end product is uranium ore concentrate. The process leaves behind waste in the form of leached ore (spent ore, or "ripios"). (view details )

Heavy Water Reactor (HWR)

runs on natural UO₂ fuel (view details )

heels (UF₆)

residue left in a UF₆ cylinder after unloading by heating in an autoclave; strong emitter of gamma radiation (view details )

hex

uranium hexafluoride (UF₆)

High Assay Low-Enriched Uranium (HALEU)

LEU with an assay of the fissile uranium isotope U-235 greater than 5 and less than 20 weight-%

Highly-Enriched Uranium (HEU)

uranium with an assay of the fissile uranium isotope U-235 of 20 weight-%, or higher (only used in nuclear weapons and in some research reactors)

in-situ leaching (ISL)

also known as solution mining or in-situ recovery, recovery of uranium from a permeable underground uranium ore body by chemical leaching (acidic or alkaline), without removal of the ore from the deposit: a leaching solution (view details ) is injected into the deposit, where it dissolves the uranium (and other minerals), before it is pumped back to the surface, where it is treated in a processing plant to recover the uranium

in-situ recovery (ISR)

in-situ leaching

light water reactor (LWR)

such as Boiling Water Reactor (BWR) and Pressurized Water Reactor (PWR), requires enriched uranium with an U-235 assay of 3-5 weight-% as nuclear fuel

low-enriched uranium (LEU)

uranium with an assay of the fissile uranium isotope U-235 greater than 0.711 and less than 20 weight-% (as used in LWRs)

low-enriched uranium plus (LEU+)

uranium with an assay of the fissile uranium isotope U-235 greater than 5 and less than 10 weight-%

MAGNOX reactor

graphite moderated, gas cooled reactor, running on natural uranium metal fuel (view details )

mixed oxide fuel (MOX)

nuclear fuel for LWRs, with some of the fissile uranium isotope U-235 replaced by plutonium (view details )
> see also: MOX Fuel Calculator

natural uranium

uranium (of any chemical form) of natural isotopic composition, i.e. containing 0.711 weight-% (equiv. to 0.72 atom-%) of the fissile uranium isotope U-235 (view details )

neutron activation

transformation of one nuclide into another, when exposed to neutron radiation; used in the nuclear industry e.g. in the following cases:

• for production of nuclear weapons material: neutron activation of U-238 in DU metal targets to U-239, which then decays via Np-239 to the fissile plutonium isotope Pu-239;
• for the use in proposed thorium-based fuel cycles: neutron activation of Th-232 to generate Th-233, which then decays via Pa-233 to the fissile uranium isotope U-233;
• for retrospective determination of the strength of the neutron radiation emitted during a criticality accident: monitoring of activation products generated from various accidentially irradiated materials;

> see also: Neutron Activation Calculator

neutron radiation

emission of neutrons, presenting mostly a long-range external radiation hazard.
In irradiated matter, it may cause neutron activation.
It results from

• controlled chain reactions of fissile material in nuclear reactors,
• accidental criticality events involving uncontrolled chain reactions of fissile material,
• spontaneous fission of certain nuclides (in particular U-238),
• alpha-neutron reactions in certain uranium compounds (in particular in UF₄ and UF₆)

nuclear fuel

• low-enriched UO₂ made from natural uranium (view details ) for LWRs, or
• low-enriched RepU UO₂ made from reprocessed uranium (view details ) for LWRs, or
• MOX fuel for LWRs, or
• REMIX fuel for LWRs
• natural UO₂ (view details ) for HWRs
• natural uranium metal (view details ) for MAGNOX reactors
• HEU fuel for some research reactors

plutonium (Pu)

artificial radioactive element formed by irradiation of nuclear fuel or depleted uranium metal targets in a nuclear reactor, occurs as various isotopes, e.g.:

• Pu-238:
• Pu-239: fissile, results from neutron activation of U-238 to U-239, and subsequent decay via Np-239
• Pu-240:
• Pu-241: fissile
• Pu-242:

(all of the isotopes listed above also undergo spontaneous fission).
can be extracted from spent fuel by reprocessing; can be used for the production of MOX fuel (view details ); also used in nuclear weapons, thus presenting a proliferation hazard.

product (enrichment)

enriched uranium in the form of UF₆

• from enrichment of natural uranium (view details ), or
• from enrichment of reprocessed uranium (view details )

prospection

uranium prospection

radiation

emission of particles or electromagnetic energy, accompanying various types of transformation of atoms, whether inherent (e.g. decay, spontaneous fission), or induced (e.g. fission by neutron bombardment, alpha-neutron reactions)

• alpha radiation: emission of alpha particles (2 protons and 2 neutrons)
• beta radiation: emission of electrons
• gamma radiation: penetrating electromagnetic radiation
• neutron radiation: emission of neutrons
• X-ray radiation: penetrating electromagnetic radiation

radiation shielding

reducing the strength of radiation by placing layers of appropriate material(s) between source and point of exposure. The shielding effect increases with the thickness of the shield material.
For the shielding of penetrating electromagnetic radiation (such as gamma and X-Ray), lead is widely used, but in certain cases also depleted uranium (as metal or U₃O₈), although it emits some radiation by itself.

radioactive

property of an unstable nuclide which disintegrates by spontaneous decay, thereby emitting radiation

radium (Ra)

radioactive element; occurs as various isotopes, e.g.:

• Ra-223: member of the decay chain of U-235; decays into Rn-219
• Ra-224: member of the decay chain of Th-232; decays into Rn-220
• Ra-226: member of the decay chain of U-238 and U-234; decays into Rn-222

further isotopes are generated during irradiation of nuclear fuel in a reactor

radon (Rn)

gaseous radioactive element generated from the decay of radium, presents an inhalation hazard, in particular from its decay products (view details ); occurs as various isotopes, e.g.:

• Rn-219: member of the decay chain of the uranium isotope U-235
• Rn-220 (thoron): member of the decay chain of the thorium isotope Th-232
• Rn-222: member of the decay chain of the uranium isotope U-238 and U-234

further isotopes are generated during irradiation of nuclear fuel in a reactor

radon daughters

radon progeny

radon progeny

decay products of radon, in particular the short-lived ones for Rn-222: Po-218, Pb-214, Bi-214, Po-214

recycled uranium

reprocessed uranium (RepU)

re-enrichment

use of depleted uranium (DU) or reprocessed uranium (RepU) rather than natural uranium as feed for the enrichment process

refining

purification step preceding the actual chemical conversion in the conversion of uranium ore concentrate to UF₆

regenerated mixture (REMIX) fuel

experimental nuclear fuel made from a mixture of reprocessed uranium (RepU) and plutonium, both extracted from spent nuclear fuel, with addition of small volumes of enriched uranium

reprocessed uranium (RepU)

uranium recovered from spent fuel in the form of uranyl nitrate hexahydrate (UNH), can be recycled into new fuel, contains unwanted uranium isotope U-236 (a neutron absorber reducing the reactivity) and other contaminants (view details )

• conversion from UNH to UF₆ for re-enrichment
• conversion from UNH to U₃O₈ for long-term storage

ripios

spent ore from heap leaching

secondary tails

tails generated from re-enrichment of depleted uranium tails

Separative Work Unit (SWU)

measure for the enrichment process, also referred to as "kg SWU"

shielding

radiation shielding

solution mining

in-situ leaching

sorting (ore)

uranium ore beneficiation process by separating chunks of higher grade material from lower grade material, using physical processes such as radiometric sorting, or X-ray fluorescence (XRF) based sorting and reverse flotation

spent nuclear fuel

irradiated nuclear fuel removed from a nuclear power plant, contains artificial uranium isotopes, transuranics, activation products, fission products, and all their decay products; the plutonium and residual uranium contained can be recovered by reprocessing (view details )

spontaneous fission

fission of an atom that occurs spontaneously (without any external trigger).
The uranium isotope U-238 and various plutonium isotopes undergo spontaneous fission at a low rate, emitting some neutron radiation, independent of their chemical compound.
> see also: Alpha-Neutron Reaction Calculator (also covers spontaneous fission)

tailings

here: uranium mill tailings
(not to be mistaken for tails!)

tails (enrichment)

here: byproduct in the form of UF₆ from enrichment of uranium

• depleted uranium from enrichment or re-enrichment of natural uranium (view details )
• depleted uranium from enrichment of reprocessed uranium (RepU) (view details )

(not to be mistaken for uranium mill tailings!)

tails assay

concentration of the fissile uranium isotope U-235 in tails, usually given as weight-percent

tails upgrading

equivalent to re-enrichment of tails

thorium (Th)

radioactive element, that naturally occurs as various isotopes, e.g.:

• Th-227: member of the U-235 decay chain
• Th-228: member of the Th-232 decay chain
• Th-230: member of the U-238 decay chain, decays into Ra-226
• Th-231: member of the U-235 decay chain
• Th-232: origin of the Th-232 decay chain
• Th-234: member of the U-238 decay chain

further isotopes are generated during irradiation of nuclear fuel in a reactor:

• Th-229: member of the Np-237 decay chain
• Th-233: obtained by neutron activation of Th-232; it decays via Pa-233 to the fissile uranium isotope U-233

Tristructural-isotropic (TRISO) fuel

spherical uranium-based nuclear fuel for experimental U.S. Department of Defense microreactors, space reactors, and civil "advanced" reactors

triuranium octoxide (U₃O₈)

chemical form of uranium in uranium ore concentrate (UOC), also used for the long-term storage and disposal of depleted uranium (DU)

UF₄

uranium tetrafluoride

UF₆

uranium hexafluoride

UNH

uranyl nitrate hexahydrate (UO₂(NO₃)₂·6H₂O)

U₃O₈

triuranium octoxide

UO₂

uranium dioxide

UOC

uranium ore concentrate

UO₂F₂

uranyl fluoride

UO₂(NO₃)₂·6H₂O

uranyl nitrate hexahydrate (UNH)

UO₃

uranium trioxide

upgrading (ore)

equivalent to beneficiation of uranium ore

upgrading (tails)

equivalent to re-enrichment of tails

uranium (U)

radioactive element that is found as natural uranium in low concentrations in most of the earth's crust, and in higher concentrations in uranium ore deposits

• natural uranium consist of three isotopes (U-238, U-235, and U-234), of which only U-235 is fissile (view details );
• all uranium isotopes are radioactive: they decay into isotopes of other elements, thereby emitting alpha or beta, plus gamma radiation,
• each of the isotopes U-238 and U-235 contained in natural uranium is the origin of a particular decay chain of decay products (view details ),
• if left undisturbed for long periods of time, natural uranium is accompanied by its decay products in secular equilibrium;
• chemical processing of uranium during nuclear fuel production changes the abundance of its decay products;
• enrichment changes the isotopic composition of the uranium,
• the uranium isotope U-238 undergoes spontaneous fission, thereby emitting some neutron radiation, even if not irradiated,
• alpha-neutron reactions in some uranium compounds produce additional neutron radiation,
• recycled uranium (RepU) recovered from spent nuclear fuel contains additional artificial uranium isotopes,
• as a heavy metal, uranium also presents a toxicity hazard (view details ),

Isotopes of natural uranium:

• U-234:
  • minor isotope contained in natural uranium;
  • emits alpha radiation, is a member of the U-238 decay series
  • is a neutron absorber reducing the reactivity in nuclear fuel
• U-235:
  • contained in natural uranium at 0.711 weight-% (equiv. to 0.72 atom-%);
  • at lower percentages contained in depleted uranium, and at higher percentages contained in enriched uranium;
  • emits alpha radiation, is the origin of the U-235 decay series;
  • is the only fissile isotope in natural uranium
• U-238:
  • contained in natural uranium at 99.284 weight-%;
  • emits alpha radiation, is the origin of the U-238 decay series;
  • undergoes spontaneous fission, resulting in some neutron radiation

Artificial isotopes generated during irradiation of nuclear fuel in a reactor:

• U-232:
  • emits alpha radiation,
• U-233:
  • emits alpha radiation,
  • is fissile,
  • also obtained by irradiation of thorium in a nuclear reactor (by neutron activation of Th-232 to Th-233, and decay via Pa-233)
• U-236:
  • emits alpha radiation,
  • is a neutron absorber reducing the reactivity in nuclear fuel
• U-237:
  • emits beta radiation,
• U-239:
  • emits beta radiation, decays via Np-239 to the fissile plutonium isotope Pu-239
  • also obtained by irradiation of depleted uranium metal targets in a nuclear reactor (through neutron activation of U-238);

uranium dioxide (UO₂)

chemical form of uranium (of any isotopic composition) used in nuclear fuel for

• LWRs: either enriched UO₂ (view details ), or enriched RepU UO₂ (view details ), or
• HWRs: natural UO₂ (view details )

uranium exploration

Uranium exploration is the process of locating uranium minerals and assessing their concentrations (grade) and quantities (tonnage), to determine if they are commercially viable ores for mining. Uranium exploration is much more intensive, organized, involved, and professional than uranium prospection.

uranium hexafluoride (UF₆)

highly toxic chemical form of uranium (of any isotopic composition) used in enrichment by gas diffusion or gas centrifugation; a grey crystalline solid at ambient temperature, it vaporizes above 56.4°C; also known as hex

• uranium hexafluoride (UF₆) from processing of natural uranium (view details )
• uranium hexafluoride (UF₆) from reprocessed uranium (RepU) (view details )

Uranium hexafluoride is chemically very reactive, and therefore presents an inhalation hazard not only for its radioactivity, but also for its chemical aggressivity.
In uranium hexafluoride, alpha radiation from the decay of uranium sets off alpha-neutron reactions with fluorine, thereby generating neutron radiation in addition to that resulting from spontaneous fission of the uranium isotope U-238.

uranium metal

uranium of any isotopic composition in the form of metal

• as depleted uranium used for radiation shielding
• as depleted uranium used for ammunition (penetrators), tank armor, and other high-density applications
• as depleted uranium used as irradiation target in reactors to produce plutonium
• as natural uranium used as nuclear fuel for MAGNOX reactors

Finely divided uranium metal presents an ignition hazard.

uranium mill

plant that recovers uranium from uranium ore that was mined in a conventional (i.e. open pit or underground) uranium mine, by mechanical (crushing, grinding) and subsequent chemical processing; the end product is either Yellow Cake, or uranium ore concentrate (UOC); the mill generates a waste stream of uranium mill tailings

uranium mill tailings

the slurry/sand-like waste arising from uranium milling, still containing 85% of the radioactivity initially present in the ore (view details )

uranium mine

facility that extracts

• uranium ore from the ground by conventional mining (i.e. open-pit or underground mining); the ore is then further processed at a uranium mill or a heap leaching facility, while waste rock is dumped at the mine site, or
• uranium from uranium ore left in its geologic setting, by in-situ leaching

uranium ore

rock containing uranium in concentrations that can be recovered economically by uranium mining (view details )

uranium ore concentrate (UOC)

marketable end product of uranium extraction from uranium ore, obtained either

• by uranium mining (open-pit or underground), and uranium milling or heap leaching, or
• by in situ leaching,

has greyish or greenish color; contains at least 90% U₃O₈; is often imprecisely referred to as "Yellow Cake", but is actually obtained from Yellow Cake by calcining (view details )

uranium prospection

Uranium prospection is the first stage of the geological analysis of a territory for the occurence of uranium minerals. Traditionally prospecting relied on direct observation of uranium mineralization in rock outcrops or in sediments. Modern prospecting also includes the use of geologic, geophysical, and geochemical tools to search for anomalies which can narrow the search area.
In case of promising results, uranium prospection is followed by the more thorough uranium exploration.

uranium tetrafluoride (UF₄)

highly toxic intermediate chemical form of uranium in various processing schemes; a green crystalline solid, also known as "green salt".
In uranium tetrafluoride, alpha radiation from the decay of uranium sets off alpha-neutron reactions with fluorine, thereby generating neutron radiation in addition to that resulting from spontaneous fission of the uranium isotope U-238.

uranium trioxide (UO₃)

intermediate chemical form of uranium in various processing schemes

uranyl fluoride (UO₂F₂)

highly toxic intermediate chemical form of uranium in the de-conversion of UF₆.
In uranyl fluoride, alpha radiation from the decay of uranium sets off alpha-neutron reactions with fluorine, thereby generating neutron radiation in addition to that resulting from spontaneous fission of the uranium isotope U-238.

uranyl nitrate hexahydrate (UNH): UO₂(NO₃)₂·6H₂O

highly toxic intermediate chemical form of uranium in various processing schemes, in particular of reprocessed uranium

waste rock (mining)

overburden and mined material with a grade too low for economic uranium extraction

X-ray radiation

penetrating electromagnetic radiation, resulting e.g. from interaction of beta radiation with matter (Bremsstrahlung)

yellow cake

originally only used for ammonium diuranate, the penultimate end product of uranium extraction from uranium ore, containing 70% - 90% U₃O₈, and named after its glowing yellow color;
today, the term yellow cake often is also imprecisely used for uranium ore concentrate (UOC) which is obtained from ammonium diuranate by calcining

UNIT CONVERSION

Uranium Contents

1 lb U3O8 = 0.385 kg U 1 million lbs U3O8 = 385 tonnes U	1 kg U = 2.6 lb U3O8 1 tonne U = 2600 lbs U3O8
1 short ton U3O8 = 0.77 tonnes U	1 tonne U = 1.3 short tons U3O8
1 tonne U3O8 = 0.848 tonnes U	1 tonne U = 1.179 tonnes U3O8
1 tonne UF6 = 0.676 tonnes U	1 tonne U = 1.479 tonnes UF6
1 tonne UO2 = 0.8815 tonnes U	1 tonne U = 1.134 tonnes UO2

Mass

1 lb = 0.45359 kg	1 kg = 2.2046 lb
1 short ton = 0.907185 metric tonnes	1 metric tonne = 1.1023 short tons

Volume

1 US gallon = 3.7853 l 1000 US gallons = 3.7853 m3	1 l = 0.26418 US gallons 1 m3 = 264.18 US gallons
1 cubic foot = 0.02832 m3	1 m3 = 35.31 cubic feet
1 cubic yard = 0.7646 m3	1 m3 = 1.3079 cubic yards
1 acre foot = 1233.5 m3	1000 m3 = 0.8107 acre foot

Area

1 acre = 4046.8 m2 = 0.40468 ha	1 ha = 10000 m2 = 2.471 acres
1 square mile = 2.59 km2	1 km2 = 0.3861 square miles

Radiation

1 pCi = 0.037 Bq 1 Ci = 3.7 x 10 10 Bq	1 Bq = 27.027 pCi
1 pCi/l = 37 Bq/m3	1 Bq/m3 = 0.027 pCi/l
1 rem = 0.01 Sv 1 mrem = 10 µSv	1 Sv = 100 rem 1 µSv = 0.1 mrem
1 rad = 0.01 Gy	1 Gy = 100 rad

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