A Kelownan Naquadria bomb is type of nuclear weapon which uses the unstable radioactive variant of naquadah known as naquadria in its core. Due to the exponential energy release of naquadria, they are far more potent than conventional nuclear or naquadah bombs.
Naquadria bombs were first developed by the nation of Kelowna on the planet that would later come to be known as Langara. Among those scientists involved in its development was Jonas Quinn. The Kelownans were developing it as a defensive weapon to discourage attacks by their rival powers, the Andari Federation and Tirania Confederacy, despite warnings from their scientists and SG-1. They eventually used it when their defeat seemed imminent. Taken aback by the power of the device, all three nations agreed to a cease-fire, eventually resulting in a united planetary government.
During the early stages of the bomb's development, a laboratory accident nearly detonated a small supply of naquadria in an explosion that would have killed millions. The disaster was averted by Daniel Jackson, who in the process exposed himself to a fatal dose of radiation. (SG1: "Meridian")
Following the bomb's use, the radiation from the detonation caused a chain reaction which began converting the naquadah deposits beneath the surface into naquadria, threatening to render the planet uninhabitable when a larger vein ultimately detonated. With the aid of SG-1 and a Goa'uld spy, the crisis was averted. (SG1: "Fallout")