Talk:Chicago Pile-1

bucket o' water

I heard that the fail-safe in case the reaction went out of control was a bucket of water. I want to include this in the article, but because it seems very unlikely, I wanted to put it in the discussion first. If anyone can confirm or deny this, let me know.

Thanks.

'TWAS NOT A BUCKET OF WATER

It was a cadmium salt solution because cadmium absorbs neutrons or somethin like that but i KNOW it was cadmium salt solution.

I agree that this article has a gaping hole in its not addressing the safety issue of creating this world's first nuclear reactor in the middle of a university in a huge city. Surely Fermi's thoughts on the matter have been documented. That, as well as the security issue are two major improvements for this article.--Tdadamemd (talk) 18:32, 20 July 2010 (UTC)

I too remember, as an undergraduate physics major in the 70s, hearing that a number of graduate students were stationed above the CP-1 pile with buckets of cadmium salt solution to slow the reaction should it begin to run away on them. I wonder if anyone can verify this? It's not completely unreasonable to think that some of those graduate students might still be living today to confirm this. If so, it would be an interesting note to include this in the article. Sloughin (talk) 17:39, 18 March 2011 (UTC)

I heard the same story during a visit in the mid-60's. One further detail, not guaranteed: the students were told to not be too quick to dump the cadmium solution, because that would require replacement of all the cadmium-contaminated graphite, etc... NitPicker769 (talk) 22:00, 2 December 2012 (UTC)

Further to the above, ref (9) in the article includes a description of the various shut-down methods, including the container of a cadmium salt solution (and an axe!)... NitPicker769 (talk) 04:40, 3 December 2012 (UTC)

Merger

The following discussion is a concluded merger discussion. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the debate was AGAINST merger of Chicago Pile-1 into Stagg Field and AGAINST merger of Chicago Pile-1 with Metallurgical Laboratory.--TonyTheTiger (t/c/bio/tcfkaWCDbwincowtchatlotpsoplrttaDCLaM) 19:31, 29 September 2007 (UTC)

Well I think a lot of this can be merged into Stagg Field, and if the nuclear part gets too long there it could become its own article under the title that the National Historic Landmarks Program uses, Site of first self-sustaining nuclear reaction. I can do it if folks would like, I just cleaned up Stagg Field and think it would be a great place for this stuff and the stuff from the other article. I am copying this to the other talk page as well.A mcmurray 04:18, 12 February 2007 (UTC)

Why use the clunkly NHL name that nobody knows? Every history book lists this as Chicago Pile-1, I see no reason to list it under any other name. --24.147.86.187 12:32, 14 May 2007 (UTC)

Agreed. That comment was three months ago though. IvoShandor 13:24, 14 May 2007 (UTC)

I also agree that this should remain Chicago Pile-1. CP-1 isn't even located at "the site of the first self-sustaining nuclear reaction"--it was moved to the former site of Argonne National Laboratory, where it was reconstructed as CP-2 and where it's remains still reside today. CP-1 and that specific site are two separate concepts. Also, Stagg Field is NOT synonymous with the nuclear reactor--it has it's own history completely separate from both the lab and reactor. Squideshi 19:28, 21 September 2007 (UTC)

I agree that this should remain at its current location and separate from Stagg Field.--TonyTheTiger (t/c/bio/tcfkaWCDbwincowtchatlotpsoplrttaDCLaM) 19:31, 29 September 2007 (UTC)

I found this article, Metallurgical Laboratory, which is a near duplicate. Let's merge 'em. Speciate 02:21, 23 August 2007 (UTC)

I strongly disagree. The Metallurgical Laboratory was a place and organization, and CP-1 was a nuclear reactor. These two topics are NOT synonymous. If you want to improve these articles, move the information about the reactor to this article and the information about the Metallurgical Laboratory to that article, and/or expand one or both. Squideshi 19:22, 21 September 2007 (UTC)

I too feel the reactor should have a separate page.--TonyTheTiger (t/c/bio/tcfkaWCDbwincowtchatlotpsoplrttaDCLaM) 19:31, 29 September 2007 (UTC)

The above discussion is a concluded merger discussion. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Proposed Split of Chicago Pile-1

I have proposed that the section entitled Chicago Pile-1 be split into its own article. This is the world's first nuclear reactor, and it deserves its own article. I would also like to see similar freestanding articles for Chicago Pile-2 and Chicago Pile-3. Squideshi 00:41, 24 May 2007 (UTC)

Oh my gosh, no kidding! This is ABSURD the way it is set up. I am doing some editing of another article and was planning on creating a link to Pile 1, and it comes to this? Absolutely, yes, split of Chicago Pile-1 NOW. Unschool 03:25, 6 June 2007 (UTC)

WikiProject class rating

This article was automatically assessed because at least one WikiProject had rated the article as stub, and the rating on other projects was brought up to Stub class. BetacommandBot 14:26, 9 November 2007 (UTC)

Graphite

In 1983 I was walking in the Cook County Forest Preserve that now occupies the reactor site. There had been a marker noting it as the reactor site but vandals had destroyed it. One day I found that the ground had been disturbed, obviously by some heavy equipment. In the mix of rocks and dirt, I found several blocks of graphite and I collected one, which I still have. It is approximately 4 inches square and maybe 1.5 inches thick. Does anyone know if this would have been part of the graphite core of the reactor?

T bingerq (talk) 18:41, 12 June 2008 (UTC)

I'm no expert; but knowing that the reactor was essentially a "pile" of graphite bricks, it seems likely. It also seems possible that the block could be radioactively contaminated and a danger to human health. I hope that you're taking appropriate precautions. You might consider having the block tested. Squideshi (talk) 18:59, 20 December 2009 (UTC)

Just a side note concerning the graphite and it's possible contamination... it (probably) isn't. I had attended a scientific glassblowing course (for chemistry majors) at University of New Mexico in Albuquerque, where some of the graphite from the original reactor had been machined for use in the glassblowing lab. This was in the mid-1990s. We were told of the provenance, and that it had been repeatedly tested, not only upon arrival, but also by the curious, who attended classes in the building, and others who were simply interested.... — Preceding unsigned comment added by 78.60.133.39 (talk) 21:59, 20 September 2013 (UTC)

No mention of secrecy?

I'm just puzzled that this entire article makes no mention of secrecy. Wasn't the pile constructed as part of the Manhattan Project, and kept entirely from the public eye? Isn't the telegraph about the Italian navigator so worded for reasons other than whimsy? --arkuat (talk) 03:43, 27 June 2008 (UTC)

Yes, it is kind of odd. Not to mention, if it was so secret, why would they invite dignitaries to watch? I'm gonna have to look into this...

--Sci-Fi Dude (talk) 18:30, 29 January 2009 (UTC)

I can not remember where; but I have read that Argonne National Laboratory, the site where Chicago Pile-2 was constructed from the same original materials, was indeed a secret facility. Squideshi (talk) 19:01, 20 December 2009 (UTC)

Wigner missing?

There doesn't seem to be any mention of Eugene Wigner (either in the article or the team photograph), though he was apparently part of the team. His "Twentieth Birthday of the Atomic Age" (in Symmetries and Reflections, pg 239-240) speaks of 'our group' and 'we', and his description of the criticality is definitely first person:

"We stood on the balcony of the court and Fermi directed the withdrawal of the rods in steps of about a foot each. After each step, the clicking of the counters started to speed up, but soon leveled off and reached a steady value. This steady clicking became higher and higher as the control rods were pulled out further and further. However, this was still "background", for the counting rate was still levelling off. Finally, at the last stage, the clicking (thus the flow of neutrons inside the pile), continued to increase and did not seem to approach a steady state. Left alone, in another few minutes the neutron count would have doubled, then doubled again during the same interval and so on.
This meant that the self-sustaining chain reaction was established; the pile was "critical". When it was certain that this stage had been reached, Fermi had the control rods reinserted and the clicking died down.
Nothing very spectacular had happened. Nothing had moved and the pile itself had given no sound. Nevertheless, when the rods were pushed back and the clicking died down, we suddenly experienced a let-down feeling, for all of us understood the language of the counters. Even though we had anticipated the success of the experiment, its accomplishment had a deep impact on us. For some time we had known that we were about to unlock a giant; still, we could not escape an eerie feeling when we knew we had actually done it. We felt as, I presume, everyone feels who has done something that he knows will have very far-reaching consequences which he cannot foresee.
I produced a bottle of imported Chianti from a brown paper bag on the balcony floor. Italian wine was appropriate because our leader, Fermi, was of Italian birth. He uncorked the bottle and we toasted the success of the experiment. As we drank the wine, we sent up silent prayers that what we had done was the right thing to do. I do not remember whewther any of us gave expression to his sentiments but we knew each other too well not to sense what was in the others' minds."

--129.49.7.125 (talk) 16:34, 23 April 2009 (UTC)

Put the picture of the reactor at the top

Not a picture of a sculpture. Seriously. — Preceding unsigned comment added by 74.70.111.59 (talk) 22:24, 22 December 2011 (UTC)

Reinserting the rods would "dampen" the reaction? Don't you mean "damp?"

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The first reactor?

How can CP-1 be the first reactor (first critical in later 1942), when the Leipzig Pile L-IV already had an criticality accident on June 23 1942? --46.5.104.58 (talk) 06:40, 30 September 2013 (UTC)

It wasn't a criticality accident. Per List of military nuclear accidents: "During the inspection, air leaked in, igniting the uranium powder inside. The burning uranium boiled the water jacket, generating enough steam pressure to blow the reactor apart. Burning uranium powder scattered throughout the lab causing a larger fire at the facility." Hawkeye7 (talk) 00:52, 3 December 2015 (UTC)

2 Type of control systems & the curious lunch call

According to this article that appeared in the new Scientist magazine, there were two primary control systems for the control rods, one electrically controlled with a knob/variable resistor from the balcony and the other titled "zip" (probably so named due to the sound wire makes when running over a pulley at an accelerating rate) under the watchful eye of the SCRAM man/axe man to cut the line/wire.

While for finer control of the neutron rate than the electrically operated dial or knob system may have provided, George Weil operated the last "rod" or more accurately a plank. Incrementally inching it out with Fermi overlooking his progress. So there were 3 human operated control "rods" in total.

Secondly, the call for lunch at 11:30 was not random as the article in its present state suggests, but occurred right after the automated control system dropped a control rod into the fail-safe postion, doing so because it was set on too fine a hair trigger/too sensitive to neutron rates. So you see, they were slowly ramping up the reactor to a self-sustaining point and then all of a sudden this safety system wipes out all their work! So it was time to take a break and start all over again! As it was, it appears they were 2nd time lucky. Who needs to wait for third anyway?

See the bottom of page 1 and the top of page 2.

http://www.waltpatterson.org/georgeweil.pdf New Scientist 30 November 1972

Moreover the paper "The first reactor" published on the 40th anniversary in 1982 also has similar info. Along with the galvanometer chart of neutron intensity, or in the authors poetic terms, the reactors "birth certificate".

185.51.75.43 (talk) 12:06, 24 March 2016 (UTC)

Accuracy?

The documentation of the building and operation of the pile described bricks of (processed) Uranium Oxide (which the Oxygen in the Oxide would be similar in moderation capability as the graphite) and some Uranium. Phrase "neutron-producing uranium pellets" is scientifically inaccurate, doesn't appear in the documentation. Purified Uranium (with decay products found in ore removed) is essentially non-radioactive: the radiation counts for natural Uranium are masked by natural radioactivity from Cosmic Rays, Potassium-40, et al. U-238, 99.2752% natural abundance, radioactive half life is about the age of the Earth. Of the small number of Uranium atopms that do decay, most decay by alpha emmission and only less than .01% by spontaneous fission (which emits neutrons). A neutron source (Berylium/Polonium probably;Little Boy:"Polonium for the initiators") was introduced to initiate reaction, standard practice for all Uranium reactors. Plutonium on the other hand with a 24,000 yr half life and typically decays by spontaneous fission, is its own neutron source and does not need initiation. References:

• http://www.uchicago.edu/features/how_the_first_chain_reaction_changed_science/
• http://www.osti.gov/accomplishments/documents/fullText/ACC0044.pdf includes "Fermi's own words" "initiator"

Shjacks45 (talk) 14:06, 4 November 2013 (UTC)