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Re: Shine - a real use for fusion, now!

Posted: Fri Mar 10, 2017 6:47 pm
by Rich Feldman
JakeJHecla wrote: ... accidental solution reactors have happened a number of times previously. In such a criticality accident, when the solution hits k=1, there's a large release of heat and radiation, but rarely an explosion. ... system will go critical yet again (often repeating many, many times)...
The Japanese built a facility called TRACY for doing that on purpose, with real fissile materials in solution, and plenty of variables. Some early results were useful for terminating the unplanned criticality at Tokai-mura in 1999.
snipped from ... 5/2_4.html

Today I couldn't re-find an online video clip that viewed a TRACY critical solution from above. Not only was the camera shielded, it was at the farthest corner of the enclosure, with telescope and mirrors in the optical path. In spite of all that, the image gets sparkly (and momentarily white) from irradiation of the camera sensor. Like the videos Andrew Seltzman has shown us from camera on conveyor cart in e-beam irradiation facility.

When the criticality at Tokaimura was over, I believe the total fission count (which power of ten) was determined by measuring the activation of coins found at the plant office and in neighbors' houses. They must have been looking at activation products with half-lives measured in hours or days. Maybe that's given in the reference given above by Jake. A friend of mine was in Japan on business at the time, and the accident interrupted his rail travel.

Re: Shine - a real use for fusion, now!

Posted: Sat Mar 11, 2017 4:39 pm
by Richard Hull
Again, fortunately, this system can't go critical even by accident or the NRC would never have issued the license to proceed. Nor, would they have ok'd the license to use and receive the fissle materials needed to make "Shine" go. Killing the fusion neutron source, (cutting its power), would force the normally subcritical operation to go deeply subcritical.

Richard Hull

Re: Shine - a real use for fusion, now!

Posted: Sun Oct 07, 2018 6:45 am
by Rich Feldman
This came up again at HEAS today, consequent to discussion about Bert Hickman, electron implantation in acrylic slabs, and video from a shielded camera on the train of carts rolling through tunnel of irradiation.

Andrew, once again I couldn't find the remembered video: looking down into a tank of uranious solutions going critical on purpose.
Found one video, generally similar, on today's website for JAEA's TRACY facility: ... en_03.html
There's a link with Japanese text, which leads to a 25-megabyte file called r-nucef-0001.wmv Not sure about the time annotation, method of reactivity insertion in this experiment, etc.
For new readers of this thread: the shielded camera is not over the mixing tank. It's at the far end of the lab, enjoying the view via mirrors and long-focal-length lenses.
There's a fixed arc In the round field of view, between angles of about 2:00 and 8:00. I think it's the boundary between turbulent liquid surface and the tank wall. Bright spots are reflections of overhead lights.

Re: Shine - a real use for fusion, now!

Posted: Sun Oct 07, 2018 7:23 pm
by Rich Feldman
Back to the nominal subject of this thread: Looks like Shine has continued its dash through the approval, funding, planning, and construction process. Here's a NYT article from January, ... onsin.html.

Well maybe not that fast -- there's always going to be self-promotional hype.
In August 2017, Wall Street Journal reported a groundbreaking ceremony in Janesville. ... fb47c.html
In June 2018, the Janesville Gazette reports "Shine to Break Ground". ... ce866.html

According to the NYT article, the city of Janesville's generous economic development package beat those of competing cities. Their General Motors plant closed in 2008, and is being demolished as we speak.

None of the articles cited here uses the words nuclear, fission, fusion, reactor, or uranium.
Except about old ways to make Mo-99.
And that the new way "does not require HEU". :-)