radionuclide
Enable an AI agent to identify a radionuclide, assess what its decay implies for a linked material inventory, and determine which uses or handling decisions require further evidence.
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.
Researched by: Codex
Purpose and description
Enable an AI agent to identify a radionuclide, assess what its decay implies for a linked material inventory, and determine which uses or handling decisions require further evidence.
It can be Resolve a supplied isotope or isomer label to a nuclear identity, or flag missing state information.; Retrieve and compare evaluated decay properties while preserving uncertainty and source versions.; Predict parent decay and daughter ingrowth for a linked inventory with explicit initial conditions.; Compare observed radiation features with expected emissions to propose or challenge an identification.; Convert atom inventory to activity, or activity to atom inventory, when the necessary decay data and assumptions are available.; Identify the additional material, exposure and authorisation evidence needed before judging a proposed use or handling action..
Distinguishing features
Atomic number alone identifies an element; radionuclide identity additionally requires mass number and nuclear energy state.
Evidence of radioactive decay distinguishes a radionuclide from a nuclide treated as stable within the stated evaluation limits.
Ground and metastable states must be resolved where they have distinct evaluated decay properties; an element-and-mass label may be insufficient.
A physical sample can contain several radionuclides and has an amount and activity at a time; the radionuclide itself denotes a nuclear species.
Different chemical compounds containing the same nuclear species do not become different radionuclides merely because their chemical forms differ.
Scope
+ Nuclide identity resolved by atomic number, mass number and nuclear energy state.
+ Decay modes, branching fractions, half-life and associated uncertainties.
+ Emitted radiation and daughter relationships, including decay-chain consequences.
+ Translation between radionuclide atom inventory and activity under stated assumptions.
+ Chemical-form and application dependencies needed to interpret the radionuclide's behaviour.
- A particular radioactive source, specimen, batch or container and its custody history.
- Chemical compound identity, formulation and bulk material properties.
- Radiation detector design, calibration and measurement-session records.
- Patient treatment plans, biological uptake models and individual dose assessments.
- Facility authorisations, transport packages and waste-management operations.
Characteristics
- Nuclear identity
- Element symbol, atomic number Z, mass number A and nuclear-state designation Prevents confusion between isotopes, isomers and incompletely specified labels.
- Nuclear excitation energy
- keV with uncertainty, or unresolved Helps distinguish nuclear states whose labels or assignments may be ambiguous.
- Half-life
- s or explicitly convertible time unit, uncertainty or bound, and applicable conditions Supports decay prediction and establishes the time scale over which inventory changes.
- Decay modes and branching fractions
- Evaluated decay modes with dimensionless fractions, uncertainties and upper limits Determines possible daughter products and how decay events are distributed among pathways.
- Emission energies and yields
- Energy in keV or MeV; yield per parent decay with the normalization stated Supports identification and radiation-field calculations without confusing yield with branching fraction.
- Daughter nuclear states
- Links to daughter nuclides and states, qualified by decay pathway Allows an agent to trace ingrowth and distinguish parent-only behaviour from chain behaviour.
- Activity of a linked inventory
- Bq at a reference time, linked to a specified inventory and uncertainty Makes activity usable without assigning a sample-dependent quantity to the nuclear species.
- Nuclear-data evaluation status
- Adopted, provisional, disputed or unresolved, with source version and date Exposes when calculations or identity decisions depend on unsettled data.
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 5 bundles · 10 layers · 10 findings · 27 questions.
Nuclear identity Resolve which radioactive nuclear species and energy state the registry entry represents.
Decay properties cannot be assigned reliably until isotope and nuclear-state ambiguities are removed.
Nuclide resolution
Establish the element and nucleon counts behind a supplied name.
Atomic and mass identification
Record the nuclear identity and the evidence connecting each accepted label to it.
- Which atomic number and mass number does this radionuclide designation identify? definition
- Which evaluated reference establishes the accepted designation and its aliases? provenance
Nuclear-state resolution
Distinguish ground-state and metastable identities and retain unresolved assignments.
State assignment
Make nuclear-state specificity explicit before attaching decay data.
- Does the designation refer to the ground state, a particular metastable state or an unresolved mixture? definition
- What excitation energy and evaluated state assignment support that interpretation? measurement
- When must an incomplete isotope label remain unresolved rather than default to the ground state? boundary
Decay behaviour Represent the time scale and competing pathways of radioactive transformation.
An agent needs decay kinetics and pathway probabilities to predict changes without treating uncertain values as exact.
Decay time scale
Capture half-life evidence and the conditions under which it applies.
Half-life evaluation
Keep the adopted half-life, uncertainty, limits and relevant environmental qualifications together.
- What half-life is adopted, with what uncertainty or bound? measurement
- Which evaluation supports that value, and does it supersede conflicting measurements? provenance
- Are the linked inventory's electronic or environmental conditions outside those assumed by the adopted decay data? boundary
Competing decay pathways
Represent decay modes and their evaluated probabilities.
Branch accounting
Distinguish established branches, bounded rare branches and unassigned probability.
- Which decay modes are established, and what branching fraction and uncertainty belong to each? measurement
- Do the reported fractions share a normalization, and are any pathways represented only by upper limits? boundary
Radiation and daughters Connect parent decay to emitted radiation and resulting nuclear species.
Identification and consequence assessment depend on both immediate emissions and subsequent daughter decay.
Emission signatures
Describe radiation features that may support identification or radiation-field assessment.
Energy and yield signature
Record emission type, energy distribution and yield with clear attribution.
- Which particle or photon emissions are expected, with what discrete energies or continuous spectra? measurement
- Are yields stated per parent decay, per branch or under a specified daughter-equilibrium assumption? definition
- Which observed features could be shared with other radionuclides and therefore require corroboration? boundary
Daughter-chain relations
Trace daughter identities and the conditions that change their contribution.
Daughter ingrowth context
Link decay products while preserving the distinction between a nuclear pathway and daughters retained in a sample.
- Which daughter nuclides and nuclear states result from each decay pathway? definition
- Which daughters were initially present, subsequently removed or lost from the linked inventory? provenance
- What evidence permits an equilibrium approximation instead of explicit daughter-ingrowth calculation? boundary
Inventory and material context Connect nuclear properties to time-specific amounts and chemically situated material.
Activity, mobility and practical persistence cannot be inferred from radionuclide identity alone.
Amount, activity and time
Support conversions and predictions for a specified physical inventory.
Inventory reference basis
Require a reference time and composition basis for inventory-derived quantities.
- What atom count, radionuclide mass or activity is known for the linked inventory, at what reference time and with what uncertainty? measurement
- Does the reported activity describe this parent alone or include other radionuclides and daughters? boundary
- Does projection to another time require accounting for production, transfer or separation as well as decay? action
Chemical and physical carriers
Link chemical form and material containment to interpretations of radionuclide behaviour.
Form-dependent behaviour
Separate nuclear identity from the material properties that govern movement and accessibility.
- In which chemical species, oxidation state and physical phase is the radionuclide present? definition
- Which linked material evidence is needed to assess volatility, solubility, leaching or daughter retention? boundary
Use and decision evidence Connect radionuclide properties to proposed purposes and the evidence required for consequential decisions.
Nuclear suitability is only part of deciding whether a particular inventory can be used, measured, stored or transferred.
Application fit
Assess the nuclear properties relevant to a proposed application.
Purpose-property match
Relate half-life, emissions and daughter products to explicit application requirements.
- Which required half-life range, emission characteristics or daughter behaviour make this radionuclide a candidate for the proposed purpose? action
- What radionuclidic composition and activity-per-mass requirements must the linked inventory satisfy? measurement
- Which application requirements depend on formulation, equipment or biological behaviour rather than nuclear identity? boundary
Handling decision dependencies
Identify missing context before reaching a handling or permission conclusion.
Context required for action
Connect intrinsic radiation properties to inventory-specific exposure and authorisation assessments.
- What activity, chemical form, containment, geometry and exposure-pathway evidence is required to assess the proposed action? action
- Which current jurisdiction-specific authorisation or classification record applies to this inventory and action? provenance
- Which missing inputs prevent the agent from concluding that the proposed action is permitted or adequately controlled? boundary
What the second pass must settle
- Does the existing Vercy catalogue already cover radionuclides within a nuclide or isotope model, requiring this registry entry to link there?
- Which evaluated nuclear-data sources and version-selection rules should govern conflicting half-lives, branching fractions and state assignments?
- What identity policy should distinguish metastable states while preserving the registry's authoritative granularity?
- Where should Vercy place daughter-chain calculations, inventory-specific activity and chemical-form links across neighbouring models?
- What evidence threshold should distinguish established radioactive decay, a decay limit and a nuclide treated as stable?