Definition of "scram"
scram1
verb
third-person singular simple present scrams, present participle scramming, simple past and past participle scrammed
(intransitive, originally US, often imperative) To leave in a hurry; to go away.
Quotations
"You scram out of here!" she admonished me fiercely. "Get out, or I'll scream so loud I'll wake the whole house up! You—you Peeping Tom!"
1943, Hans Natonek, “The Affair of the Semi-private Bathroom”, in Barthold Fles, transl., edited by Sugden Tilley, In Search of Myself, New York, N.Y.: G[eorge] P[almer] Putnam’s Sons, part 2 (The Year before the Decision), page 89
scram2
verb
third-person singular simple present scrams, present participle scraming or scramming, simple past and past participle scramed or scrammed
(transitive) To shut down (a nuclear reactor or, by extension, some other thing) for safety reasons, usually because of an emergency.
Quotations
The NCR [Nuclear Regulatory Commission] further demands the plant conform to all the safety requirements put into effect during construction. This means constant re-design. There must also be several ways to scram (emergency shut down) the reactor. Some of these are automatic and some are manual.
1976 December, Randy Warsaw, “Fermi II – A Plant Tour”, in Ray Barry, editor, The Michigan Technic, volume XCV, number 3, [Ann Arbor, Mich.]: College of Engineering, University of Michigan, page 15
Startup of reactor recirculating pump resulted in flux spike scraming plant.
1978, “Appendix II—Answers to Written Questions Posed to Nuclear Regulatory Commission before the Hearings”, in Nuclear Regulatory Commission Authorization Requests: Hearings before the Subcommittee on Energy and Power of the Committee on Interstate and Foreign Commerce, House of Representatives, Ninety-fifth Congress, Second Session, on the Nuclear Regulatory Commission’s Requests for an Increased Authorization for Fiscal Year 1978 and for a Fiscal Year 1979 Authorization of $330,000,000: […] (Serial No. 95-161), Washington, D.C.: U.S. Government Printing Office, page 794
The slightest problem in a reactor will cause the control rods to plunge automatically in the uranium core at high speeds (this is called scramming the reactor) and stop the chain reaction.
1983, Michio Kaku, Jennifer Trainer, editors, Nuclear Power, Both Sides: The Best Arguments for and against the Most Controversial Technology, New York, N.Y.: W[illiam] W[arder] Norton, page 22
Both active and manual methods scram by tripping power to a dedicated pump that unbalances the flows to the[sic] passively scram the reactor.
2000, Ralph R. Fullwood, “Analyzing Nuclear Reactor Safety Systems”, in Probabilistic Safety Assessment in the Chemical and Nuclear Industries, Boston, Mass.: Butterworth-Heinemann, section 6.1.4.3 (ABB PIUS), page 218
The reactor was then "scramed", but the control rods did not slide back into the reactor.
2007 June 22, Samuel Upton Newtan, “Nuclear Reactor Disasters: Part I: Stationary Reactors (Non-breeders)”, in Nuclear War I and Other Major Nuclear Disasters of the 20th Century, Bloomington, Ind., Milton Keynes, Buckinghamshire: AuthorHouse, page 113
Raising group eight rods and brining a nuclear reactor fully to life for the first time in nearly ten years—everyone was so ready they were all ready to pee in their pants. Andrews did not know he could do it without SCRAMing the reactor—in other words, pushing it into an automatic shutdown that might be too little too late.
2012 December 12, D. Michael Battey, chapter 35, in Tenacity Gene, Bloomington, Ind.: iUniverse, page 174
(intransitive) Of a nuclear reactor or some other thing: to shut down, usually because of an emergency.
Quotations
As soon as the earthquake struck, the reactors "scrammed"—shut down automatically—as they were supposed to.
2012, Daniel Yergin, “The Urgency of Fuel Choice”, in The Quest: Energy, Security, and the Remaking of the Modern World, revised edition, New York, N.Y.: Penguin Books, part 3 (The Electric Age), page 415
Immediately after the earthquake, following government regulations, the remaining reactors, 1–3, automatically SCRAMed; control rods shut down sustained fission reactions.
2016, Nabil Abu el Ata, Rudolf Schmandt, “Understanding the Hidden Risk of Dynamic Complexity”, in The Tyranny of Uncertainty: A New Framework to Predict, Remediate and Monitor Risk, Berlin, Heidelberg: Springer, part I (Once upon a Time), page 21
noun
plural scrams
(also attributively) A shutdown of a nuclear reactor (or, by extension, some other thing), often done rapidly due to an emergency.
Quotations
During scram operation, a scram signal de-energizes the inlet and outlet scram valves. The outlet scram valve vents the volume above the drive piston to a scram dump tank. The inlet scram valve supplies scram pressure obtained from an accumulator to the under side of the vented piston.
1960 October 5, John Roberts, S. F. Armour, “Introduction”, in T7 Tanker Locking Piston Control Rod Drive Scram Analysis (GEAP 3561), Oak Ridge, Tenn.: Office of Technical Information, United States Atomic Energy Commission, page 2
Of the 14 scrams experienced, none was caused by operation exceeding the design parameters. Eight scrams occurred with the control rods withdrawn. [...] Six scrams occurred while the rods were inserted. Five were intentional to prevent accidental rod withdrawal, and one was the unintentional result of an instrument adjustment.
1966 fall, staff of First Atomic Ship Transport, Inc., “Operating Experience of the N.S. Savannah in Commercial Service”, in Nuclear Safety: A Quarterly Technical Progress Review, volume 8, number 1, [Oak Ridge, Tenn.]: Division of Technical Information, United States Atomic Energy Commission, section VI, page 65
By the time scram is completed, coolant temperatures would likely be climbing due to the combination of a large heat capacity within the fuel pins and low coolant flow.
1981, Alan E. Waltar, Albert B. Reynolds, “Unprotected Transients”, in Fast Breeder Reactors (Pergamon International Library of Science, Technology, Engineering and Social Studies), New York, N.Y., Oxford, Oxfordshire: Pergamon Press, section 15-5.D (Loss of Ultimate Heat Sink), page 604
Although fission stops almost immediately with a SCRAM, fission products in the fuel continue to release decay heat, initially about 6.5% of full reactor power. [...] Corresponding with the SCRAM, emergency generators were automatically activated to power electronics and cooling systems.
2016, Nabil Abu el Ata, Rudolf Schmandt, “Understanding the Hidden Risk of Dynamic Complexity”, in The Tyranny of Uncertainty: A New Framework to Predict, Remediate and Monitor Risk, Berlin, Heidelberg: Springer, part I (Once upon a Time), page 21
Other indicators can be used to measure the performance of an NPP [nuclear power plant] including the number of scrams (emergency shutdowns of a nuclear reactor), the collective dose (a measure of the total amount of effective dose multiplied by the size of the exposed population), the amount of low-level waste generated, and the fuel reliability. The number of scrams dropped from the peak of 30 in 1984 to only one in 2004 and 2–3 in the last two years.
2011, Min Lee, “The Past, Present and Future of Nuclear Power in Taiwan”, in Xu Yi-chong, editor, Nuclear Energy Development in Asia: Problems and Prospects, Basingstoke, Hampshire: Palgrave Macmillan, page 171
The device used to shut down a nuclear reactor; also, the button or switch used to initiate a shutdown.
Quotations
Each room housing a radiation source has a red-buttoned "scram" switch on the wall. One touch of the switch and all equipment stops abruptly.
1963 June, Kenneth Calkins, “Linac and Dynamitron”, in Boeing Magazine, volume XXXIII, number 6, Seattle, Wash.: Public Relations Division, Boeing Airplane Company, page 6, column 2
In particular, measures have been taken to make the scram system more fast-operating and to exclude any possibility of its being deliberately shut off by the personnel.
1998, Vladimir M. Munipov, “Ergonomics [Disregarding Ergonomic Design Principles: Chernobyl]”, in Jeanne Mager Stellman, editor, Encyclopaedia of Occupational Health and Safety, 4th edition, volume I, Geneva: International Labour Office, page 29-96
Today it is considered to be true that the accident paradoxically was ultimately caused by the emergency shut down of the reactor. By sending in the practically completely withdrawn scram and control rods, the reactivity of the reactor by the faulty conception of the rods was for a short time not lowered, but augmented.
2004, Dieter Berg, “Radionuclides Released into the Environment”, in Richard Tykva, Dieter Berg, editors, Man-made and Natural Radioactivity in Environmental Pollution and Radiochronology (Environmental Pollution), Dordrecht: Springer Science+Business Media, page 119
scram3
verb
third-person singular simple present scrams, present participle scramming, simple past and past participle scrammed
(transitive, Derbyshire, Wales) To scratch (something) with claws or fingernails; to claw.
Quotations
A woman has praised firefighters and her cat for saving her life following an alleged arson attack. Two-and-a-half-year-old tortoiseshell Taffy repeatedly bit owner Tracie Horgan-Hodgkiss on the hand until she woke up when her flat filled with acrid smoke in the early hours of this morning. [...] "I’d like to say thank you very much to the firefighters for coming to rescue me. And I am sorry that Taffy scrammed one of them!"
2013 December 19, Abby Bolter, “Firefighters Rescue Woman Trapped in Bridgend Flat following an Alleged Arson Attack”, in WalesOnline, archived from the original on 24 December 2013
(transitive, US, mining, archaic) To mine for ore on a small scale, especially from mines previously been worked on where most of the ore is believed to have been removed.
Quotations
Just west of this pit is another one, which has been nearly worked out; but three men are scramming about five tons per day in it.
1880, “Marquette Iron District”, in Annual Report of the Commissioner of Mineral Statistics of the State of Michigan, for 1879, Lansing, Mich.: W. S. George & Co., […], page 167
Recently, Capt. Oliver, [...] set a couple of experienced miners to work scramming in this underground pit, when it was soon discovered that what the former mining captain had conceived to be a regular foot-wall, was, in fact, a thin shale of rock, which hid from view what now appears to be a very large body of clean blue ore.
1882, A. P. Swineford, “The Cyclops Mine”, in Annual Review of the Iron Mining and Other Industries of the Upper Peninsula for the Year Ending Dec. 31, 1881, [Marquette, Mich.]: Mining Journal, page 141
noun
plural scrams
(US, mining, archaic) A mine previously worked on where most of the ore is believed to have been removed, but which is still being mined on a small scale.
Quotations
[page 64] Many of these old openings still afford places where ore is mined. A man can start in almost anywhere and fine ore. There is a great deal of this "scramming" done at the Jackson. Quite a proportion of the annual product comes in this way. Not unfrequently one of these "scrams" leads to the finding of a large deposit of ore. [...] [page 67] South from the east part of the Incline pit they have a scram of good ore which furnished a small product.
1887, Cha[rle]s D. Lawton, “The Jackson Iron Co.”; “The Cleveland Mining Co.”, in Mines and Mineral Statistics, Lansing, Mich.: Thorp & Godfrey, […], pages 64 and 67
There are numbered workings running to about 20, representing small pits and scrams, sometimes worked by contract by "scrammers."
1891, N[ewton] H[orace] Winchell, H[orace] V[aughn] Winchell, “The Chandler Mine”, in The Iron Ores of Minnesota, […] (Geological and Natural History Survey of Minnesota Bulletin; no. 6), Minneapolis, Minn.: Harrison & Smith, […], part II (Methods of Exploration and Mining, and Descriptions of the Various Mines), page 196
scram4
verb
third-person singular simple present scrams, present participle scramming, simple past and past participle scrammed
Of one's body or limbs: to become numb or stiff due to cold, lack of movement, etc.
Quotations
But though he had breeches and waistcoats to spare, / He had nothing quite seemly for Barbee to wear, / Who, half shrammed to death, stood and cried on a chair / At the caddle she found herself in.
1866 (date written), Thomas Hardy, “The Fire at Tranter Sweatley’s”, in Wessex Poems and Other Verses, New York, N.Y., London: Harper & Brothers, published 1898, page 191
To be weakened by an accident, a disease, starvation, etc.
Quotations
"But they will be scrammed!* the children will be scrammed, Mary, before morning," cried Jim, scratching his head with perplexity and distress at the very thought of two young creatures sleeping on the bare boards, in a cold garret with only a shawl to cover them. [Footnote *: Starved.]
, chapter I, in How Mary Edmonds Did What She Could; and What Came of it after Many Days, London: The Religious Tract Society, […], pages 14–15