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Open it As such they can be a biological hazard, depending upon dose.
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Neutron - Wikipedia led to the first self-sustaining nuclear reactor (Chicago Pile-1, 1942) and the first nuclear weapon (Trinity, 1945). Free neutrons, while not directly ionizing atoms, cause ionizing radiation. <span>As such they can be a biological hazard, depending upon dose. A small natural "neutron background" flux of free neutrons exists on Earth, caused by cosmic ray showers, and by the natural radioactivity of spontaneously fissionable elements in th
last interval [days]
repetition number in this series
scheduled repetition interval
last repetition or drill
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