2. To drop the control rods into a reactor core. Originally coming from the acronym Super-Critical Reactor Axe Man coined during the original testing of reactor design using graphic bricks as a moderator. In the event of a highly supercritical reaction, the axe man would cut the ropes causing the rods to be fully inserted and supress the neutron flux and thereby drastically reduce the fission rate and rate of heat production.
3. (slang) To turn something off. Derived from the above and used primarily by nuclear engineering majors or nuclear operators in the Navy.
2. The reactor scrammed on an automatic protective feature.
3. My computer started smoking so I scrammed it.