View Full Version : Origins of Crud and Scram

Squid Vicious
10-10-2000, 09:34 AM
In the parlence of nuclear power, CRUD is an acronym of Chalk River Unidentified Deposits and SCRAM is Safety Control Rod Axe Man. My question is whether or not these terms were in the everyday lexicon already or did they spring out of the nuclear arena. Is there evidence of these terms being used before WWII?

10-10-2000, 10:06 AM
Collins English Dictionary

1. a sticky substance, esp. when dirty and encrusted
2. an undesirable residue from a process, esp. one inside a nuclear reactor
.... C14: earlier form of CURD.

Scram (1):
vb. ...informal. to go away hastily, get out.
C20 shorted from scramble
1. an emergency shutdown of a nuclear reactor
2. (of a nuclear reactor) to shut down or be shut down in an emergency C20 perhaps from scram (1)

(Collins English Dictionary)

It looks as though the nuclear power people were deliberately making acronyms to fit already existing words.

10-10-2000, 10:45 AM
A bit off topic, but does anybody know for sure about the "Safety Control Rod Axe Man" thing? I'm not entirely convinced it's true, but a lot of people seem to think it is. The Jargon File entry for "scram switch" is skeptical of this origin but does not say for sure, and I couldn't find anything about it on Snopes.

The reason I want to know is that I work at a research reactor and the SCRAM story is part of the standard spiel we give during tours, and I don't want to be spreading an urban legend.

10-10-2000, 11:00 AM
Bobort, I'm not sure if you are asking whether the acronym derivation of "scram" makes sense, or whether the word predates the nuclear industry. But it seems that the verb "scram" would predate the specialised acronym (which does sound a bit contrived). Meriam-Webster online thinks that the verb "scram" ("go away! You're not wanted here.) dates from circa 1928, and I'm sorry, but it freaked out and gave up when I wanted the noun "scram".

FWIW, I'd think that the word would be about that age (or older) if it comes from "scramble" as WW1 aircraft chappies were forever "scrambling" (if kids' stories/film are to be believed). Oh, maybe disregard the last bit then!

Squid Vicious
10-10-2000, 11:36 AM
FWIW I used to teach a class in reactor physics for the navy. In the instructors guide there was a section of "oolies" or interest builders. The origins of scram and crud (as far as nuclear power terms) were presented in there as Safety Control Rod Axe Man and Chalk River Unidentified Deposits complete with backgroud stories. The explanations seemed plausable and I never went out of my way to investigate them for accuracy. I suppose it wouldn't be the first time that UL got mixed in with otherwise credible material, so anything's possible.

I was pretty sure that scram predated the U of Chicago's experiment but I'm still not sure about CRUD.

10-10-2000, 11:38 AM
Sorry about being ambiguous. I want to know whether SCRAM, as used in the nuclear industry, was indeed coined as an acronym of "Safety Control Rod Axe Man" by the people working on the Chicago pile in the '40s. The standard story goes like this:

The first nuclear reactor was built under a squash court at the University of Chicago by Enrico Fermi et al in (I forget what year exactly). [So far this is verifiably true] As a safety measure, they had a special control rod that was suspended out of the core by a rope; this control rod, if inserted, would bring the reactor subcritical. There was a person with an axe (usu. said to be a grad student) standing by the rope ready to cut it in an emergency. This person was called the Saety Control Rod Axe Man, and the signal to cut the rope was the word SCRAM.

The part about the control rod on a rope is at least plausible, but the acronym sounds contrived. What I specifically would like to know is 1) was the setup at the Chicago pile as described? 2) did they in fact use the word scram? 3) if so, did they choose it based on this acronym, or did somebody invent the acronym after the fact? If scram was a pre-existing word, its use in the nuclear industry could still be consistent with the story, but I doubt the above story is entirely accurate.

10-10-2000, 12:18 PM
According to the OED

Crud is an obsolete and dialect form of "curd", in which case it seems to have had something like its present meaning for several centuries. The meaning of "undesirable impurity" or "foreign matter" seems only to date from about 1950 and seems to be connected to the nuclear power industry. My WAG is that the nuclear CRUD acronym was devised to reflect an existing usage and in doing so, reinforced it.

Scram clearly predates the advent of nuclear power since the earliest quote is from 1928 (other quotes, all pre-war are from Punch, D L Sayers and Nancy Mitford). The Dictionary suggests that it is probably an abbreviation of "scramble" but might be related to the German schrammen, to go, depart or run away.

10-10-2000, 01:21 PM
Can I do a tiny hijack to ask Squid Vicious how the word "oolies" for interest-builders came about? Maybe it is in common use, and I just haven't heard it.

Squid Vicious
10-11-2000, 08:33 AM
I really have no idea where oolies came from. I've never heard it used outside the Navy, but within the navy (or at least the nuclear navy) it's used quite extensively.

Other strange idioms from the navy:
gedunk -candy or snacks
whamadyne -used as in "super whamadyne air compressor", etc.
zarf -cup holder
dink -delinquent
nub- newbie

There are others I can't recall right now.

10-11-2000, 09:08 AM
"Zarf" at least is a real word (a cupholder for those glass cups one sometimes uses) Apparently from an Arabic word for container or sheath.

New world government policy announcement: should world peace ever break out, certain naval/military service people can be employed as a public neologism department, to be named "oolies". I imagine there will be plenty of time to construct an acronym to fit!