Radionuclide calculators

A free set of calculators for radiation safety, dosimetry and the nuclear industry — decay, dose rate, shielding, unit conversion and reference data from NNDC/ENSDF, IAEA LiveChart, DDEP/LNHB, NIST XCOM and ICRP-116/Peplow.

Basic and regulatory calculations

Unit conversions and calculations using physical and regulatory formulas.

Decay

DecayIsotope activity at a date, required initial activity, time to target.

Unit converters

Activity unitsConvert becquerel, curie and submultiples (Bq ↔ Ci).

Activity ↔ massMass ↔ activity for any nuclide by half-life.

Specific activitySpecific activity in Bq/kg, Bq/L and Bq/cm².

Dose unitsConvert sievert, gray, roentgen and rem.

Transport & packaging

Transport indexTransport index (TI) and package category for Class 7 carriage.

Source categoryRadioactive source category 1–5 by A/D ratio (НП-067-24).

A1/A2 and package typeExcepted / Type A / Type B package by A1/A2 values (SSR-6, НП-053-16), with Kvant УКТ limits.

Sample analysis

Effective activityEffective specific activity Aeff and material class (NRB-99/2009).

Personal dosimetry

Individual dose Hp(10)Gamma and neutron Hp(10), calibration settings and period totals.

Model-based estimates

Results depend on the source model, geometry, composition or measurement method.

Nuclear materials

UraniumUranium mass ↔ activity by enrichment and chemical form.

PlutoniumPlutonium mass ↔ activity by grade and composition.

Dose & shielding

Dose rateGamma dose rate, inverse-square law and ALARA scenarios.

ShieldingLead/concrete thickness, half-value layer and build-up.

Beta doseSkin-dose estimate using 32 tabulated factors.

Bremsstrahlung / X-rayBremsstrahlung yield and X-ray dose estimate.

Sample analysis

MDC/MDAMinimum detectable concentration/activity (Currie).

Gamma spectrometrySample activity from a gamma photopeak (efficiency, yield, live time).

Decay

Half-lifeHalf-life from two activity measurements over time.

Reference data

Nuclear and regulatory data with source-specific limits.

Reference tables

Gamma-ray dose constantsEffective-dose constants for 1192 nuclides (Peplow / ICRP-116 AP).

Half-life tableHalf-lives of 3561 radionuclides (ENDF/B-VIII.0) with search and sort.

Gamma lines by energyIdentify a radionuclide by gamma-peak energy (keV ± tolerance).

Specific activity tableSpecific activity of pure radionuclides, Bq/g and Ci/g.

D-values tableD-values (dangerous activity) of 352 radionuclides — НП-067-24 / IAEA RS-G-1.9.

Dose limits НРБ-99/2009Basic dose limits (Table 3.1) for personnel and the public, with a share-of-limit check.

Online calculators for radiation safety and dosimetry

What the calculators cover

A free toolkit for radiation safety and dosimetry. The calculators cover everyday tasks: decaying a source activity to a date, finding a half-life, computing gamma dose rate and shielding, converting radiological units, estimating specific activity of materials and detection limits.

Data sources and reliability

All calculations are deterministic and rely on open scientific data — NNDC/ENSDF decay data (ENDF/B-VIII.0, 3561 nuclides), NIST attenuation coefficients, ANS-6.4.3 build-up factors. The data source and version are stored with every saved calculation, and values are marked as reference: verify against the source certificate and applicable regulations before any operational or safety decision.