Radiation Sickness

Radiation Sickness is a disease tied to exposure to radiation in Oxygen Not Included. It becomes a concern anywhere duplicants spend time near strong radioactive sources or directly in irradiated environments, especially around late-game nuclear equipment and radioactive materials.

The most intense common source listed is the Research Reactor, which emits 12,000 rads per cycle in a 25-tile radius. If the reactor melts down, it emits about 24,000 rads per cycle in the same radius, then decays to 0 after 5 cycles. Other significant sources include:

• Radioactive Contaminants: 11 rads per 10,000 units, affecting only natural tiles or constructed tiles, not loose items, bottled elements, or contents in pipes or rail systems.
• Depleted Uranium: 55 rads per 1,000 kg within 3 tiles; liquefying it into Liquid Uranium produces stronger radiation.
• Uranium Ore and Solid Nuclear Waste: 165 rads per 1,000 kg within 3 tiles.
• Liquid Uranium and Liquid Nuclear Waste: 165 rads per 1,000 kg within 3 tiles; because these are liquids, Radbolt Generator can be built inside them.
• Nuclear Fallout: 17 rads per 1,000 kg within 3 tiles; liquefying it into Liquid Nuclear Waste produces stronger radiation.
• Crushed Satellite: 2,400 rads per cycle within 12 tiles.
• Shine Bug: 60 rads per cycle within 6 tiles.
• Radiation Bee and its larva: 1,440 / 480 rads per cycle within 5 / 3 tiles, but only while asleep.
• Beeta Hive: 442 rads per cycle within 5 tiles, released in pulses only while refining Uranium Ore.
• Wheezewort: 480 rads per cycle within 6 tiles, whether wild or domesticated.

Radiation from asteroids also matters. The background cosmic radiation level depends on the asteroid, ranging from 125 to 375 rads per cycle in the exposed space region, with some locations such as Far and Spaced Out asteroids showing notably higher values. Radbolt impact itself also contributes 12 rads per Radbolt within 6 tiles for about 2 seconds.

In practice, Radiation Sickness is a positioning problem: keep duplicants away from reactors, radioactive debris, and high-radiation machinery unless they are protected or need to work there briefly. Radioactive materials are dangerous primarily when present as natural tiles or dense mass near a duplicant, so storage, containment, and distance are the main ways to reduce risk.