First 3D Simulations of Complete Nuclear Detonations

jhiv writes: "The National Nuclear Security Administration (NNSA) reports that 'Los Alamos and Lawrence Livermore national laboratories have completed the first full-system three-dimensional simulations of a nuclear weapon's explosion'. The simulations are two of the largest computer simulations ever attempted, each taking weeks to complete on the ASCI White supercomputer. The Los Alamos team used the ASCI Blue Mountain supercomputer to visualize the results. Additional coverage can be found in this story in the Albuquerque Journal."

Comments

Certification of the stockpile

[T5]

By law, the directors of the nuclear weapons labs (Sandia, Los Alamos, and Lawrence Livermore, IIRC) are required to certify annually the readiness of the nuclear stockpile. This has been a problem due to the lack of production of tritium in the US, with the exception of a small amount from Savannah River in South Carolina and just recently at the Tennessee Valley Authority's Watts Bar Nuclear Plant in Tennessee. Without sufficient quantities of tritium, the aging thermonuclear arsenal's decay of tritium puts the existing weapons at risk of not functioning within their design parameters. The only thing more frightening than a nuke that works is one that you can't rely on to work when needed. Thus, the directors have threatened to not certify the arsenal.

With this new computing power, the directors can now verify the status of even degraded weapons whose functionality was up till now a mystery and make better decisions about how to use the still small amounts of tritium being produced.

Re:What exacly are they trying to learn?

[thesupraman]

It's quite simple, they are trying to find out how long the current weapons will keep working, and how the rate of failure changes over time.

These devices contain quite an amount of rather radioactive material, which emits a lot of high energy particles, this causes other materials around them to change over time, therefore then need to know if they will stay safe, and will work if required.

The worked out how to build a 'big enough bomb' quite some time ago, but building new devices is expensive, as it blowing them up from time to time for testing, simulating the 'aging' devices is a much cheaper and simpler option, as well as providing supercomputing power for 'other' work.

Re:will this work?

[dohnut]

Well, they weren't H-bombs, but yes..

Study: 1950s nuclear fallout worse than thought

Re:Innovation...

[jimhill]

"We're lucky 'The National Nuclear Security Administration' even lasted through that mess of 8 years. Thoughts anyone?"

Yeah, here's a thought:

With all due respect, kwishot, like many Slashdot posters you're posting out of your ass and while you might win points among the equally ignorant you turn yourself into a laughingstock for those with a greater understanding.

The nuclear weapons complex is under the purview of the US Department of Energy. Almost since it was created from AEC/ERDA in the mid 1970s, DOE has been under attack for its poor organization, poor administration, and poor security record. Multiple panels and commissions and auditors spent their time submitting final reports and recommendations suggesting that the security aspect of the weapons complex be removed from DOE control or at least placed in the hands of a semi-autonomous agency.

After the _annus horribilis_ that was 2000 for Los Alamos, support both public and Congressional was high for these recommendations to be implemented. New Mexico Republican Senator Pete Domenici introduced legislation which would create the National Nuclear Security Administration as a semi-autonomous agency within DOE and that legislation passed with support from both parties and was signed into law by Democratic President Clinton. (Side note: then Energy Secretary Bill Richardson, former Democratic Congressman from, yep, New Mexico, took a well-publicized pummeling from members of both parties, not least of which was West Virginia's Democratic Senator Robert Byrd, who told Richardson that he could never vote to confirm Richardson for another government position again.)

I'm not a supporter of Clinton's -- his decision to appoint Hazel O'Leary as his first Energy Secretary will be a long, Long, LONG time in overcoming (among her since-revoked brilliant ideas was eliminating the color-coded badges which were used to provide a visual cue of a person's clearance level in favor of a less "discriminatory" monochrome badge). To fall to your knees and give thanks that an agency created in the closing year of his administration survived the eight year Reign of Terror just reveals that you don't have the first clue what you're addressing. Next time you're tempted to fire off a post on a topic to whose table you bring complete ignorance, may I suggest that you instead spend a few moments educating yourself -- and only then, if you feel you have something of value to contribute, should you click on "Submit".

Re:How do you simulate a nuclear explosion?

[T5]

Mostly thermodynamics, plasma dynamics, fluid dynamics, nuclear physics, and about $110M for the iron.

Re:will this work?

[Waffle Iron]

Instead, what is usually done is to encase the hydrogen (tritium actually) in additional uranium or plutonium.

IIRC, tritium is very rare and only a few grams are used to "boost" the fission trigger. The main fusion fuel in most H bombs is a mixture of lithium and deuterium, which conveniently combine to form a solid chemical compound.

At any rate, in many bombs, the fusion is not even the main source of energy. It is used as a massive source of neutrons, instantly converting hundreds or thousands of pounds of dirt cheap unenriched uranium into fissionable fuel (unenriched uranium also avoids worries about dangerous multiple critical masses in one bomb). Many bombs get only about 1/3 of their energy from actual fusion, the rest is from the fast-neutron induced fission of the uranium blanket surrounding the fusion core. The end result orders of magnitude more fallout isotopes than a simple A-bomb.

In 20 years we can do it at home

[dmendesf]

First, ASCI White specs: Name: ASCI White Built by: IBM over a period of 5 years for the Department of Energy Price: for $110 million. Power: 1,000 times more powerful than IBM's Deep Blue; capable of roughly 12.3 trillion calculations per second CPU: Made of off-the shelf IBM Power3 processors (well, 8,192 of them altogether) RAM: 16 terabytes Disk space: 160 terabytes Power requirements: 3 megawatts of electricity (would light up 3,000 homes) Now let's say 1 Power3 = 1 domestic processor of today... By Moore's law, in 18 months our computational power will double, so: 2^x = 8192 x = 13 13 * 18 months = 19,5 years conclusion: video games will be very cool in 20 years

you're close....

[Anonymous Coward]

There are 365.25 day in a year according to the Julian calendar. The calendar in use through most of the world at present is the Gregorian calendar, in which there are 365.2425 days in a year. The Julian calendar was switched to the Gregorian in 1582. Well, the Catholic world switched over on that date, other countries followed shortly after.
There are countries that use other calendars than
the Gregorian, most notably the USSR calendar and the Iranian calendar. Both of these are more accurate than the Gregorian, each losing about one day every 150,000 years, while the Greogrian loses a day approximately every 5000 years. Now I'm rambling, but my point is that nobody uses a calendar with 365.25 days in a year anymore.

Re:will this work?

[Sakhmet]

Yup, you can kill a lot of the people a lot of the time, but you can't kill all the people all the time.

Reading these comments frightens me. Badly. Does anyone here even think that tactical thermonuclear devices are a good idea? Like, good enough to warrant having one in your backyard for your little sister to play on? Not me, and not my little sister.

Sakhmet.

Re:will this work?

[MullerMn]

IIRC, tritium is very rare and only a few grams..

Tritium is rare as it has a half life of only 12 years, but it can be produced my bombarding Lithium with neutrons. This is how currently designed Tokamak fusion reactors create part of their own fuel.

--
Andy