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Research draft

thorium

vr.tr.thorium · PHY.MAT

Let an agent describe thorium and its properties, relay isotopes, uses and the thorium fuel cycle from chemistry and nuclear references at a public level, relay safety and regulation, and distinguish thorium from uranium without operational detail.

Thing Registry Physical world and living systems

Research draft, second pass

A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.

written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify

Researched by: Claude

Purpose and description

Let an agent describe thorium and its properties, relay isotopes, uses and the thorium fuel cycle from chemistry and nuclear references at a public level, relay safety and regulation, and distinguish thorium from uranium without operational detail.

A weakly radioactive chemical element with symbol Th and atomic number 90, a silvery actinide metal, with the primordial isotope thorium-232 having a half-life of 14 billion years and other isotopes such as thorium-230 used in dating corals and sediments, thorium-229 with a nuclear isomer thorium-229m studied for nuclear clocks, thorium-231 and the historical radioactinium thorium-227; thorium occurs in monazite sands, was used in gas mantles and alloys, and is studied as a nuclear fuel in thorium fuel cycles.

What it is for: Dating, alloys, historical mantles and prospective nuclear fuel.

It can be describe properties and isotopes; relay uses and fuel cycle context; relay safety and regulation; distinguish from uranium.

Distinguishing features

Primordial radioactivity

Fertile nuclear material

Monazite source

Nuclear clock isomer

What it looks like

A silvery metal that tarnishes to grey or black.

Physical character

atomic number: 90 count

thorium-232 half-life: 14.05 billion years

melting point: 1750 C

crustal abundance: about 3-4 times uranium ratio

How it is recognised

Actinide element 90

Thorium-232 primordial; Th-230, Th-229 and Th-229m, Th-231, Th-227 radioactinium, Th-238

Uranium is element 92; thorium dioxide is thoria; monazite is the ore mineral

Related models

is a kind of - in registry terms

actinide

occurs in - sands

monazite

is fertile for - in thorium fuel cycles

uranium-233

is used in - through thorium-230

uranium-thorium dating

In practice

Families and kinds

thorium-232 and the thorium decay series

thorium-230 in uranium-thorium dating

thorium-229 and the thorium-229m nuclear isomer

thorium-231 and thorium-227 in the uranium-235 series

thorium compounds such as thoria

thorium fuel cycle concepts

Identifiers

symbol Th

CAS 7440-29-1

Standards and regulation

Radiation protection laws and IAEA safety standards

Nuclear material regulation and safeguards

Rules on naturally occurring radioactive materials in mining

Failure modes and hazards

Radiation and radon exposure from thorium ores

Agents providing operational nuclear detail

Overstating thorium reactor readiness, with positions attributed

Also called

Radioactiniumthorium-231thorium-230thorium-229mthorium-229thorium-238thorium-237thorium-236thorium-235thorium-234thorium-233thorium-209thorium-210thorium-211thorium-212thorium-213thorium-214thorium-215thorium-216thorium-217thorium-218thorium-219thorium-220thorium-221thorium-222thorium-223thorium-224thorium-225thorium-226thorium-227thorium-216m1thorium-216m2thorium-208thorium-239thorium-228thorium-232

Where this came from

wikidata · CC0 1.0

Also registered as vr.tr.thorium

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.

Understand What thorium is.

Science.

Properties

Properties.

Properties

Properties.

  1. What are the physical and chemical properties of thorium, and how does it compare with uranium? definition
  2. Is the question about the element, an isotope, the fuel cycle or operational matters the model does not cover? boundary

Isotopes

Isotopes.

Isotopes

Isotopes.

  1. What isotopes exist, and what are thorium-230 dating, the thorium-229m nuclear clock isomer and radioactinium? definition
  2. Which entry fits the specific isotope? action
Use Uses.

Application.

Historical

Historical and current uses.

Historical

Historical.

  1. How has thorium been used in gas mantles, alloys, optics and welding electrodes, and why have many uses ended? provenance
  2. Which references are standard? provenance

Nuclear

Thorium fuel cycle.

Nuclear

Nuclear.

  1. What is the thorium fuel cycle, what has been tried, and what do proponents and critics say, with positions attributed? provenance
  2. Is the presentation neutral and non-operational? boundary
Occur Occurrence and safety.

Regulation.

Occurrence

Occurrence and mining.

Occurrence

Occurrence.

  1. Where does thorium occur, and how is it extracted from monazite, in general terms? provenance
  2. Which sources are cited? provenance

Safety

Safety.

Safety

Safety.

  1. What radiological hazards does thorium pose, and how is it regulated? provenance
  2. Which entry fits radiation protection? action
Context History and science.

Context.

History

History.

History

History.

  1. How was thorium discovered by Berzelius and named after Thor, and how was its radioactivity found? provenance
  2. Which entry fits the history of the actinides? action

Science

Dating and clocks.

Science

Science.

  1. How are thorium isotopes used in geochronology and in nuclear clock research? provenance
  2. Which entry fits nuclear clock? action

What the second pass must settle

  • Should the thorium fuel cycle be a separate primary entry?
  • How should nuclear data sources be linked?
  • The registry entry has merged aliases naming isotopes and a historical name; should they be split off?