dog nougat posted:

MasterBuilder posted:

I assume that if something went wrong it would fail into the negative position.

quote:

With Topsy still in operation, a second critical assembly for basic studies, Lady Godiva (she was unclad, like the lady), began operation in 1951. This essentially bare sphere of enriched uranium, simpler than the two-component Topsy, had not been planned earlier because of undetermined sensitivity to outside influence—facetiously, even the effect of a fly alighting on the surface. The critical size was established earlier by means of a near-critical pseudosphere set up on the Comet machine. The Lady Godiva sphere, on the Elsie machine, was subdivided into a stationary central section with retractable upper and lower caps (Fig. 8). The central section contained a diametral glory hole with fillers, and channels for two highly enriched uranium control rods. Compensation for openings in the glory hole was provided by mass-adjustment buttons of enriched uranium that fit into recesses in the spherical caps. Lightweight component mounts resulted in
small extraneous reflection.

By late 1962, the usual critical characteristics of Lady Godiva had been thoroughly established. Calibration of control rods and mass-adjustment buttons, and the reactivity equivalence of enriched uranium as a function of radius provided the means of correction to an idealized sphere (i.e., without surface irregularities or nonuniformities). Other features of the standard survey were extensive. In addition, however, positive periods were measured throughout 97% of the interval between delayed and prompt criticality. Because extrapolation was predictable, plans to investigate the behavior of Lady Godiva in the neighbortiood of prompt criticality were then formulated.

Here, the account of Lady Godiva must be interrupted to introducethe second kiva, a result of the original kiva becoming overloaded to the extent of frequent three-shift operation. Kiva 2 was occupied a t th e beginning of 1953. After Lady Godiva was moved to the second kiva, its operationwas extended gingerly into t h e prompt-critical region with t h e result that superprompt-critical radiation pulses (Fig. 9) were being produced by mid-1953. These sharp, intense pulses were terminated by thermal expansion of the assembly. At one stage, Lady Godiva was moved outdoors and elevated well above the ground (Fig. 10) to eliminate the effect on pulse shape of room-return neutrons. The resulting shapes agreed with calculation.

Although intended initially to confirm predicted superprompt-critical behavior, the sharp, intense pulses were immediately in demand as sources for biological studies (Fig. 11), solid-state experiments, and proof tests of instrumentation and controls that were supposed to withstand radiation from a nuclear explosion. The result was that Lady Godiva became a radiation source and produced a total of about 1000 of the prompt-radiation bursts— but not without incident. Twice the delicate limit beyond prompt criticality that could be tolerated was exceeded. The first, which occurred in February 1954, warped uranium parts slightly but not sufficiently to prevent further operation. The second, 3 years later, was more extreme. It produced severe warping and oxidation of parts and damaged the lightweight supports (Fig. 12). As a result. Lady Godiva was retired and replaced by Godiva II, a sturdier bare U(93) assembly designed specifically for prompt-burst production.

Platystemon posted:

The central section contained a diametral glory hole with fillers

Don't Ask posted:

https://i.imgur.com/s2CekWr.mp4

By popular demand posted:

Fun fact: glory hole is originally a mining term and thus a good subject for this thread!

madeintaipei posted:

What does it mean in a mining context?

Flash Gordon Ramsay posted:

In some mines, in the men's bathroom, there's a hole cut into the side of the stall and

Flash Gordon Ramsay posted:

In some mines, in the men's bathroom, there's a hole cut into the side of the stall and

madeintaipei posted:

What does it mean in a mining context?

Cartoon Man posted:

Gonna link this cause it’s disturbing. Guy gets hit by a bus, picks himself up, dusts himself off, and continues on into the Pub for drinks like he gives a gently caress.

https://imgur.com/gallery/v9o3YPw

ekuNNN posted:

https://va.media.tumblr.com/tumblr_qycuocvR0W1r0uzl6.mp4

Cartoon Man posted:

Gonna link this cause it’s disturbing. Guy gets hit by a bus, picks himself up, dusts himself off, and continues on into the Pub for drinks like he gives a gently caress.

https://imgur.com/gallery/v9o3YPw

Woozie66 posted:

I don't think you'll be able to guess the end of this.

https://www.tiktok.com/embed/7000111249363127557

CommieGIR posted:

The solution to the method seen here was the Lady Godiva Device, which allowed you to do this test remotely



Seen here is Godiva I, which also had an incident which resulted in warping parts of the device from heat/neutron exposure. Thankfully, the device was operated remotely with the operators receiving minimal exposures. It had two incidents like this.
https://en.wikipedia.org/wiki/Godiva_device

Rebel Blob posted:

https://www.youtube.com/watch?v=QqfyUJDzWrQ

We know what book the owner of the sailboat hasn't read.

The Lone Badger posted:

Is that because freshwater is gentler on the metal?

The Lone Badger posted:

Is that because freshwater is gentler on the metal?

Fornax Disaster posted:

It also illustrates how very old some Great Lakes shipping is. Towards the end the camera zooms in on Cuyahoga and you can see that hull is riveted together like the frickin' Titanic instead of welded.

mobby_6kl posted:

I just know how to avoid them

kimihia posted:

It’s hard to find parking for a helicopter.

Megillah Gorilla posted:

Disgruntled Bovine posted:

I thought the whole point of that "experiment" was to play chicken with a criticality accident.

CommieGIR posted:

Effectively, yes. How else do you get the good data?

LifeSunDeath posted:

Scholtz posted:

Cross post from the meme thread: