NUCLEAR ENGINEERING · HEALTH PHYSICS
Decay, dose and shielding. Every number sourced.
Eleven calculators built on the IAEA chart of nuclides and the NIST attenuation tables. Every screen cites the dataset it used and the textbook section behind the formula.
Free calculators · no account · works offline · 174 published checks
- NUCLIDES
- 3,383IAEA NUBASE2020 / AME2020
- GAMMA EMITTERS
- 130Line spectra from ENSDF
- SHIELD MATERIALS
- 9NIST μ/ρ and μen/ρ
- NETWORK CALLS
- 0The data ships in the app
Eleven tools
⚛︎Chart of Nuclides
All 3,383 ground states plus 661 metastable isomers, coloured by decay mode. Pan, zoom, filter by half-life. Tap any nuclide for its branches, spin-parity, decay chain, isomers and neutron cross sections.
AtDecay Calculator
A(t) = A₀e−λt for any isotope or isomer — Tc-99m included — or enter your own half-life. Works forward from a calibration date and backward to one.
γDose & Shielding
Point-source dose rate summed over the real emission spectrum, with ANSI/ANS-6.4.3 buildup, half- and tenth-value layers, and ALARA stay time. Also solves for distance or thickness.
σMDA / Counting
Currie critical level and detection limit. Minimum detectable activity and concentration, plus a gross-count detection decision.
XeXe-135 Simulator
Xenon transients for shutdown, startup and step changes. Gives the reactivity worth and the time the iodine pit peaks.
k∞Formula Explorer
Six-factor formula and point kinetics on live sliders. Shows k_eff, prompt-jump reactivity, stable period and dollars.
⇆Unit Converter
Activity, absorbed dose, dose equivalent, dose rate, energy and exposure. Includes the ICRP 103 weighting factors.
ρMixture & Enrichment
Parses chemical formulas, converts weight and mole fractions, breaks down composition by element, and runs a cascade mass balance with SWU.
ΣDecay Chain
Full Bateman solution across a chain. Classifies equilibrium, plots activity against time, exports CSV.
μPhoton Transmission
Transmission against thickness for nine materials across the NIST energy grid, with buildup on or off.
n°Neutron Activation
Activation product build-up and decay under a chosen flux, with saturation activity and presets for common facilities.
Where the numbers come from
Every dataset is pulled from its publisher by a script and named on the screen that uses it. The few hand-entered tables — buildup factors, a set of neutron cross sections, ICRP weighting factors — carry a citation on every entry. The validation page shows 174 checks of the results against published values.