Ionactive interactive

A radioactive decay heat calculator from Ionactive. This calculator is for the curious who might wonder what thermal heat is produced from the decay of radioactive material. Classic examples of decay heat include that from spent nuclear fuel, either inside a shut down reactor, or from highly radioactive fuel removed for cooling and decay (usually in wet storage ponds, or dry ventilated stores). Another example is the use of Co-60 in industrial irradiation processes where the huge activity involved produces adventitious heat that needs to be removed from the process. In some cases radioactive material is combined with a thermocouple to produce electricity - a classic example of this is the RTG (radio-thermoelectric generator) which often uses Sr-90 (Y-90 being the key here). On a far smaller physical scale, radioisotopes such as Pu-238 have been used in pacemakers where the intense alpha particle emission heat has been harvested by thermoelectric conversion to produce the electrical energy required for reliable operation. On a much larger scale Pu-238 has powered the Voyager space probes and continues to do so. In this Ionactive calculator we provide a number of radioscopes which you can investigate raw thermal output (e.g. W/Bq), and idealised comparisons with powering electric bulbs, charging phones and running electric bar fires.  Or go deeper, and investigate how water might be heated, how long it would take to charge your phone (using more realistic efficiency), and a realistic RTG output from a given radionuclide and activity. 

A Diagnostic X-ray Shielding / Transmission Calculator by Ionactive. This resource can be used to explore transmission and shielding in a number of materials for the x-ray energy region of 25-150 kVp. The shielding materials include lead, concrete, steel, gypsum, plate glass and wood. Whilst advertised as a diagnostic x-ray calculator, since the x-ray data is taken from typical medical x-ray tubes (e.g. HVT of 3mm AL at 80 kVp), its potential use is far wider. This calculator can be used for basic primary shielding calculations in the medical sector, but does not consider workload, distance or occupancy. The calculator is flexible enough to be used in the research and industrial sectors when relatively low kVp x-rays are utilised. The analysis provided by the calculator is one of its significant features and is used to explore how transmission may be represented by 10th value & half value thickness (TVT & HVT). It also illustrates that whilst TVT/HVT is normally adequate for heavily attenuated photons (in this energy range), lighter attenuation can significantly over estimate shielding design if a fixed TVT/HVT is used. The calculator can also be used to choose alternative shielding materials for a given kV and desired transmission.  The calculation process uses published resources (referenced) with some Ionactive algorithms to fill in for missing data. This calculator reports instantaneous dose rate, if you are looking for a medical shielding assessment then try our Medical Imaging Radiation Shielding Calculator (new for August 2026) which considers modality, workload, occupancy etc. 

A beta emitter skin dose rate calculator by Ionactive. This calculator will estimate skin exposure (HP 0.07) from surface contamination of over 100 radioactive substances. Choose radionuclide activity and surface spread and calculate dose rate per hour or minute. Investigate effect of an air gap (e.g. between inner surface of contaminated glove and the skin). Modify the likely skin dose by considering use of shielding materials. Use the glove calculator to show the layers of glove material required to attenuate direct radiation exposure to the skin.  Inputs and outputs can be specified in SI and Non-SI units. The calculation process uses published data (referenced) with some near field Ionactive algorithms for dose rates near to the skin, and through various cover material. Whilst we stand by the robustness of this calculator, we include an optional 'Varskin' selector to more directly align the calculator with expected varskin output (reasoning supplied in the detailed calculator release notes). 

A beta emitter radioactivity to dose rate calculator by Ionactive. Choose a radionuclide and activity at a specified distance from the source (point or planar source), and output the dose rate (absorbed dose in air).  Choose to show various shielding materials (air, tissue, acrylic, gloves) and see the thickness for total attenuation based on beta Emax (in Mev). All inputs and outputs can be specified in SI and Non-SI units. The calculation process uses published data (referenced) with some near field Ionactive algorithms for dose rates very close to the source. 

A radioactivity to dose rate to calculator by Ionactive. Choose a radionuclide and activity, and output the dose rate at a specified distance from the source (with or without shielding). Alternatively, specify a known dose rate and a desired dose rate, and output the thickness of shielding required for a given radionuclide at a desired distance. All inputs and outputs can be specified in SI and Non-SI units. Also see a plot of dose rate vs activity and configure as you like.

The calculation process uses adaptive buildup to avoid under or over exaggerating the dose rate or shielding. As with our companion calculator (Dose Rate to Radioactivity), dose rate and shielding parameters have been validated with MicroShield and OpenMC. 

A handy Radiation Protection Units Conversion Calculator. Conversions for dose, dose rate, activity, shielding and exposure are included. SI and non-SI units are included.