The depleted material stream in isotope uranium enrichment. enrichment tails retain uranium, so gross feed demand exceeds the enriched product mass.

A unit of isotope-separation work used in fuel-cycle accounting. If stream masses are in kilograms and $x$ is isotope mass fraction, $S=PV(x_p)+WV(x_w)-FV(x_f)$ is in kg-SWU, with $V(x)=(1-2x)\log [(1-x)/x]$. This is a resource-accounting relation, not equipment or cascade design.

An increase in the fraction of a specified uranium isotope. Fuel-cycle accounting tracks feed, product, enrichment tails and separative work; it does not specify an uranium enrichment plant or its operating conditions.

The operating interval between specified refuelling events. It must be distinguished from the full material nuclear fuel cycle and from an individual fuel batch's multi-cycle residence time. Reactivity history, thermal limits and fuel management constrain the achievable interval.

The approximate invariance of the strong nuclear force under isospin rotations. It compares channels with the same spin, orbital and total-isospin quantum numbers; it does not identify the spin-triplet isospin-zero deuteron channel with the spin-singlet isospin-one neutron-neutron channel. Electromagnetic effects and quark mass differences break the approximation.

A dineutron is a two-neutron system. There is no vacuum bound state at physical parameters. In the low-energy $s$-wave channel, the spatial state is symmetric, and two neutrons have symmetric isospin; the Pauli exclusion principle therefore requires antisymmetric total spin, the spin-singlet channel. Other orbital angular momentum channels have different exchange constraints. An unbound vacuum pair does not rule out correlated neutron pairs inside a larger atomic nucleus or neutron pairing in dense matter.^[ref]

A two-proton system. Its low-energy spin-singlet strong channel does not give a vacuum bound state, and electrostatic repulsion further opposes binding. This is distinct from proton pairing correlations within an atomic nucleus.

Formation of a deuteron from a neutron and a proton with photon emission. For an initial pair at rest, two-body energy and momentum conservation gives $E_{\gamma }=B-B^2/[2(m_p+m_n)]$ in natural units, where $B=m_p+m_n-m_d$. The missing binding energy becomes nuclear recoil.

The approximately bounded binding energy per nucleon and approximately constant interior density of well-bound medium and heavy nuclei. The short effective range and many-body character of the nuclear force prevent each nucleon from binding independently to every other nucleon with an unsuppressed long-range attraction.

A nuclide formed in or descended from nuclear fission. The inventory includes unstable species and their decay products and evolves with irradiation and elapsed time.

Nuclear fission induced before the incident neutron has slowed to thermal energies. It allows otherwise non-thermal-fissile fuel constituents such as uranium-238 to contribute to fission power. A change in their fission fraction need not mean a change in total power.

Nature 278, 219–223; abstract and natural-analogue rationale.

Key Engineering Materials 48–50, 717–721; ANSTO primary research record.

MRS Proceedings 663, 259; abstract reports 2M, 4M and pyrochlore transitions.

Primary conference record; lead author S. Muraoka, with H. Mitamura, S. Matsumoto, E. R. Vance and K. P. Hart.

Waste-form development paper; section on long-term uranium-daughter criticality and neutron absorbers.

Journal of Nuclear Materials 249, 175–189; flow-through dissolution, blanks and flow dependence.

WS-R-5; historical, superseded by GSR Part 6; paragraph 1.5.

GSR Part 6; paragraphs 1.9–1.10 distinguish planned strategies from exceptional entombment of a nuclear facility.

SSG-40; section 6 covers treatment, conditioning and gaseous-waste management.