Nuclear Radiation

Nuclear Radiation adds a physics-based radiation hazard system, tracking source activity in becquerels through environmental fields and shielding to biological dose in sieverts, with distinct behavior for alpha, beta, gamma/X-ray, and neutron radiation. Radioactivity can come from placed blocks, dropped item stacks, fluids, and containers holding radioactive materials; the world also tracks soil, air, and water contamination by chunk, and sources can irradiate nearby blocks so they may change. More than 40 isotopes, including uranium-235, plutonium-239, cesium-137, iodine-131, strontium-90, cobalt-60, and californium-252, decay according to their half-lives, with decay chains producing daughter isotopes such as uranium-235 from plutonium-239. Exposure includes radiation from nearby sources, hot items carried in the inventory, and isotopes ingested or inhaled, as well as background radiation that can vary by dimension and biome; prolonged exposure can mutate mobs. Stone, iron, gold, water, obsidian, and netherite can shield radiation, with denser materials offering stronger attenuation and different effectiveness against X-rays and neutrons; armor and the mod’s full-body hazmat suit provide additional protection. A Geiger counter reports nearby activity through clicks that speed up as it rises, while a dosimeter displays total dose, current dose rate, and external, inventory, and internal dose sources; intense fields add screen static, and dropped radioactive items can glow. Protective treatments include iodine pills against iodine-131 uptake, Prussian blue to clear cesium-137, an anti-radiation injection and Radaway to reduce accumulated contamination, and a potion that resists incoming dose. Map makers and modpack authors can configure a tunable creative radiation emitter, assign radioactivity to items, blocks, and fluids through datapacks or KubeJS, and adjust armor shielding and simulation settings; JEI and EMI provide reference pages for isotopes, radioactive items, decay chains, armor protection, and related information. The mod also integrates radiation from Mekanism and Nuclear Science into its shared isotope-based system, so those sources use the same dose and shielding mechanics.