Novel Model Illustrates The Finer Details Of Nuclear Fission (phys.org)

mdsolar quotes a report from Phys.Org: For nearly 80 years, nuclear fission has awaited a description within a microscopic framework. In the first study of its kind, scientists collaborating from the University of Washington, Warsaw University of Technology (Poland), Pacific Northwest National Laboratory, and Los Alamos National Laboratory, developed a novel model to take a more intricate look at what happens during the last stages of the fission process. Using the model, they determined that fission fragments remain connected far longer than expected before the daughter nuclei split apart. Moreover, they noted the predicted kinetic energy agreed with results from experimental observations. This discovery indicates that complex calculations of real-time fission dynamics without physical restrictions are feasible and opens a pathway to a theoretical microscopic framework with abundant predictive power.

Comments

Hmmm

[Anonymous Coward]

Oh damn, now we have to redo all the nuke simulations again.

How much computation you ask?

[mdsolar]

The researchers extended the density functional theory (DFT) modeling method designed for electronic structure systems to strongly interacting many-fermion systems and real-time dynamics, creating a time-dependent superfluid local density approximation (TDSLDA). For the study reported, evaluating the theory amounted to solving 56,000 complex coupled nonlinear, time-dependent, three-dimensional partial differential equations for a 240Pu nucleus using a highly efficient parallelized graphic processing unit (GPU) code. The calculations required 1760 GPUs and 550 minutes total wall time on Titan, a Cray XK7 supercomputer located at the Oak Ridge Leadership Computing Facility (OLCF).

Re:How much computation you ask?

[caffeinated_bunsen]

So what are the implications for reactor design, physicists?

Probably not much. There's so much empirical data about the behavior of fission in reactor-like conditions that, even without a deep understanding of why things happen that way, we pretty much know what happens. That's almost certainly why they simulated the reaction they did -- we have tons of data about it already, so you can tell if the model's good.

Some slight refinements might show up eventually, but the impact of a model like this on reactors will be small.

Most nuclear physicists aren't researching fission reactors, though. The ones pushing the boundaries of the field, coaxing colliders into producing heavier nuclei, investigating weird excited states, and such, are the ones who will really notice this.

Good article, shame about the readers

[Anonymous Coward]

Finally news for nerds. It may not be revolutionary, but the interesting parts are that this model can make predictions that can be tested, and that one result differs significantly from current thinking.

This article holds far more interest for me than all the boring, pointless "multinational company X has problems producing random plastic widget Y" articles put together. Seriously, no nerd should be in the remotest bit interested in business chat that implies humanities future progress will soon vanish up its own backside in an orgy of consumer-driven pointlessness.

That modern Slashdot posters (I assume most of them are almost at the point where they could be considered capable of reading) don't find this at all interesting speaks volumes about how sites such as this have been flooded by shallow "norms" leading to the flight of and self-censorship by intelligent readers.

Re:Good article, shame about the readers

[Rei]

I wonder if this model applies as well to spallation. I would assume that it would...

Re:Good article, shame about the readers

[PPH]

the nerd population of Slashdot likes news like this, but does not have much of anything to post about it.

It's interesting news. And it's pretty advanced stuff, such that a number of Slashdot readers might understand it. But few are in a position to ask questions or discuss it without further study.

The Wayland/systemd/Windows flame wars exist because quite a few people on Slashdot are not only familiar with the subject matter, they have a level of expertise (in some cases greater then the developers) allowing them to remark 'WTF were they thinking?'

Clarification on "model"

[Anonymous Coward]

These days, one tends to think that by "model", they mean a woman on a magazine's cover. However, those type of models do not necessarily have a detailed understanding of nuclear physics. Usually. Sadly.

News for (nuclear physicist) nerds!

[torkus]

For once - actual nerd news. Something not written by a teenager aimed at the least common denominator...

Assuming I'm understanding correctly, this will allow simplified simulations of nuclear fission on a larger scale without having to run the intense calculations each time. Hopefully this leads to new understanding of the fission process and refinements to our use of nuclear power. The more we can control the fission process the more we can develop techniques to limit waste products and refine the overall use.

Nuclear fission is fairly simple and produces enormous energy for a given input...but the variables involved make plants large, safety measures redundant (by intent) and costs high. If we can simplify things and bring costs down by better understanding the atomic process then maybe 'too cheap to meter' could actually be a thing one day.

Renewable has it's place, energy storage has it's use, baseline power is important as well.

Arbitrarily Cheap Power

[Tenebrousedge]

Nuclear fission is fairly simple and produces enormous energy for a given input...but the variables involved make plants large, safety measures redundant (by intent) and costs high. If we can simplify things and bring costs down by better understanding the atomic process then maybe 'too cheap to meter' could actually be a thing one day.

Not that nuclear power should not be cheaper, but "too cheap to meter" will never happen and should never happen. There are negative externalities that need to be priced into the cost of producing power from any source, and eventually we are going to run up into some hard thermodynamic limits to how much energy we can produce without cooking ourselves. We're going to end up (in a few centuries) in a thermodynamic zero sum game. This may be as good as it gets for power costs, and we probably should think carefully about anything that would provide incentives for greater power use per capita.

There is nothing wrong with making nuclear power cheaper, but any power source being "too cheap to meter" would probably do more harm than good.