Sunday, December 8, 2013

The Atom Blanket

Here's an oddity.   While skimming old Newsweeks, I found a photo from the AP in 1954 of an "atom blanket".

Sunday, December 1, 2013


In the summer of 1969, the US Army Corps of Engineers' Nuclear Cratering Group visited the island of Hawaii.

Monday, October 14, 2013

The Liquid-Jet Super-Flux Reactor

Neutrons, besides being one of the building blocks of matter, are also an essential tool in many scientific experiments.   And the most cost-effective source of neutrons is a nuclear reactor.

In a research reactor, neutrons are produced by uranium fission; some are used to sustain the chain reaction while the rest are leaked onto an experimental target.   Various tricks can be used to maximize the neutron production of a reactor but, beyond that, if you need more neutrons than a given reactor can provide, you build a bigger reactor.   But some experiments depend instead on the neutron flux - the neutron density in volume times time.   Increasing a reactor's power increases the total number of neutrons produced, but if the size of the reactor also increases then the flux remains the same, since the neutrons are spread out over a larger volume.   A higher neutron flux requires not just more power, but a higher power density in the reactor core.

Power density is limited by cooling.   Fission produces heat as well as neutrons, and if the reactor produces more heat than the cooling system can remove, the fuel rods melt.   This is generally considered a design flaw.   A higher flux can be produced by "pulsing" the reactor - running it at very high power, then shutting down to allow the cooling system to catch up - but this can only produce a high flux for a brief period at a time.

Los Alamos scientists in the late 60s wanted to go beyond the limits of conventional research reactors.   Neutron flux is limited because heat cannot be removed quickly enough from the fuel.   But what if, instead, they removed the fuel from the heat?

In the Liquid-Jet Super-Flux Reactor (LJSFR), a fluid fuel would be pumped into the reactor, then, after fissioning, be pumped rapidly back out.   By cooling the fuel outside of the reactor vessel, a power density - and therefore neutron flux - far beyond conventional reactors could be achieved.

Thursday, September 26, 2013

Nuking Hurricanes

It is the (semi-)official policy of the National Oceanic and Atmospheric Administration that we should not try to nuke hurricanes.   (No, seriously, it is.)

We were not always so unambitious.

Sunday, September 22, 2013

A Creative Use for Decommissioned Submarines

While doing research for a future article, I ran into something interesting: in the early 60s, the US Naval Civil Engineering Laboratory studied converting decommissioned World War II submarines into bomb shelters.

Thursday, September 12, 2013

Rock to Hide Me

Those Magnificent Men and their Atomic Machines

Rock to Hide Me: Herman Kahn, Civil Defense, and the Manhattan Shelter Study

With Special Thanks to the Staff of the US Fire Administration Library

One can almost hear the President saying to his advisors, 'How can I go to war – almost all American cities will be destroyed?' And the answer ought to be, in essence, 'That's not entirely fatal, we've built some spares.'” -Herman Kahn[K]

Note on Notation
The value of the dollar has been different from year to year. In each case, unless otherwise specified, values will be given in the amount for the year in question, followed in parentheses by the equivalent value in 2012 dollars. Equivalent values are calculated using The Inflation Calculator.

The Early Years of Civil Defense
In December of 1950, President Harry S Truman announced the formation of the Federal Civil Defense Administration (FCDA). With UN forces falling back before the Chinese onslaught in Korea, world war – nuclear war – seemed imminent. The FCDA's mission was to protect American citizens if that war should come.

The crisis receded; the UN forces threw the Chinese back and the war settled into a long stalemate. But the larger threat of the Soviet Union remained, and the possibility of a surprise attack – a bolt from the blue, an atomic Pearl Harbor – was an almost universal fear, a fear the FCDA was supposed to deal with.

Truman's FCDA proposed to protect citizens with a network of government-built bomb shelters. But, with the stalemating of the war in Korea, Congress refused to allocate funds to actually build any shelters, and the whole concept of public shelters was abandoned with the arrival of the Eisenhower administration and the hydrogen bomb in 1952. The enormous power of the H-bomb – a hundred to a thousand times greater than the bombs dropped on Japan – led to a seemingly inescapable conclusion: the cities were doomed. Bomb shelters were pointless; they simply could not be made strong enough to survive, not for a price Congress or the fiscally conservative Eisenhower administration were willing to pay.

Eisenhower FCDA administrator Val Peterson argued instead that the only defense was “not to be there” when the bomb went off. When the Distant Early Warning RADAR stations spotted an incoming attack, every city in the nation would empty, the population moving en masse by bus and private car to receiving areas in the countryside in the few hours before the bombers arrived. Evacuating millions of people in a few hours was a mind-boggling logistical task – and, sooner or later, intercontinental rockets arcing over the North Pole would reduce those hours to thirty minutes.

Then, in 1954, a US nuclear test in the Pacific overshot its projected yield. CASTLE BRAVO spread radioactive contamination a hundred miles downwind, sickened dozens of Japanese fishermen and Marshallese islanders, and made horrifically clear that distance alone would not protect the evacuees. Fallout from high-yield nuclear surface-bursts would make large areas lethally radioactive for days or weeks. Even if the cities were successfully evacuated, the evacuees would still have to be provided with shelters.[Bl][Mc]

By 1956, Val Peterson had changed his mind and asked President Eisenhower for $32.4 billion ($270 billion) to build public blast and fallout shelters. President Eisenhower responded by appointing a committee, commonly called the Gaither Committee after its chairman, to study not just Peterson's proposal, but the whole question of civil defense. At the committee's first meeting in August 1956, he set them a simple question: “If you make the assumption that there is going to be a nuclear war, what should I do?” The committee soon expanded its mandate to cover all aspects of this question, reviewing the United States' entire defense policy, but civil defense remained a core issue.[Bl][Ka][Gh]

The FCDA and the Gaither Committee were not the only people thinking about how to protect the civilian population. With civil defense policy in flux, a new voice entered the debate – a young, roly-poly nuclear strategist named Herman Kahn. In 1956, a member of Kahn's civil defense group at the RAND think-tank proposed a radical new solution to the problem.[Gh] There would not be time to flee to the countryside – but, if city-dwellers could not escape horizontally, perhaps they could escape vertically.

A vast network of deep underground tunnels and dormitories could be built under every major urban area in the country. When warning came, every man, woman, and child would descend 800 feet into the earth, deep enough to survive a direct hit by a high-yield nuclear weapon. There they would remain for three months until the radiation in the city's ruins dropped to safe levels. The project would be preposterously expensive, requiring excavation and construction on a titanic scale – engineering commensurate to the scale of the problem it was intended to solve. But its inventors believed it could ensure the survival of 86% of the American people, even in the face of all-out thermonuclear war.

Figure 1: Model of Manhattan Shelter Study[Pa]
(Copyright Expired)

Saturday, August 17, 2013


In the late 60s, Wold & Jenkins, a Wyoming coal exploration company, in conjunction with the US Atomic Energy Commission, proposed nuking the Tertiary Fort Union coal formation in Wyoming.

In 1967, the AEC's Plowshare program - investigating peaceful uses for nuclear explosions - turned ten years old.   Plowshare investigated a wide variety of concepts, but the main inspiration for the program - and source of political backing - was nuclear excavation, the use of hydrogen bombs, as Edward Teller put it, in "geographical engineering.   We will change the Earth's surface to suit us."
[TB]   But after ten years, despite extensive nuclear testing, the AEC seemed to be getting further and further away from actual operational employment of the technology, due to treaty limitations on atmospheric nuclear tests and growing public concern over the radiological consequences.   As a result, the program began to shift towards alternative uses, what the AEC called "underground engineering": fully-contained underground applications of nuclear explosives, in cooperation with private industry (who would also shoulder much of the development costs), in which, at least in principle, no fallout would escape into the environment.

Thursday, July 25, 2013

Total Atomic Defense

I've been on a bit of a civil defense kick lately (you'll see why in a few weeks if all goes well), and as part of that I ran across an odd little book called Total Atomic Defense from 1952, by one Sylvian G. Kendall.   Kendall was a former Army colonel who served in the US expedition to Siberia after World War I, itself a rather odd and regrettably forgotten (at least in the US) episode in history.   His only previous writing experience seems to have been an account of the expedition published in 1945.   TAD is part of a subgenre of works I like to call "atomic exhortations", about What Should We Do About the Bomb.   However, unlike most exhortations published around this time, Kendall doesn't have much use for the UN, world government, or disarmament treaties, which were the other exhorters' preferred solutions.   No, Kendall takes a very different view: his book is about how to survive the Bomb, not about how to get rid of it.   His preferred solution, though, isn't bomb shelters, which he sees as a classic example of refighting the last war.   Kendall was an advocate of dispersal.

Figure 1: Total Atomic Defense Cover
(Public Domain)

Saturday, July 20, 2013

Happy Moonwalk Day

Forty-four years ago today, at 10:56 PM EST, humans first touched the surface of another world.

Never forget that.   Amidst all the headlines of war and depression and chaos, never forget that we can do great and mighty things.

Monday, July 15, 2013

The Philosopher's Bomb, Part 1

Magnificent Men and their Atomic Machines

The Philosopher's Bomb: Discovering New Elements with Nuclear Explosions

Part I

With special thanks to Dr. Steve A. Becker and Dr. David W. Dorn

At seven o'clock in the morning, on November 1st, 1952, a man pushed a button on a control console on the USS Estes. Fourteen minutes and 59.4 seconds later, a series of detonators fired on the island of Eniwetok. The explosives compressed a hollow sphere of uranium-plutonium alloy to a fraction of its former size; at the same moment, a burst of neutrons from the initiator in the sphere's center split a handful of atoms. Those fissioning atoms released more neutrons, which split more atoms, releasing more neutrons, building in a fraction of an instant to apocalyptic force.

The superheated plasma began to push out from the boiling heart of the primary – but the X-rays leapt ahead of it, bouncing down the bomb casing to a refrigerated canister of cryogenic deuterium-tritium wrapped in polyethylene. The X-rays evaporated the plastic, the vapor pushing like rocket exhaust, compressing the D-T around a thin rod of uranium, which began to fission itself, releasing still more energy – and the fusion reaction ignited as deuterium + tritium became helium-4 + neutron, a torrent of heat and light that shattered the morning calm with the force of 10.4 million tons of TNT. This was IVY MIKE, the United States' first test of a hydrogen bomb, a weapon tapping nuclear fusion – the same process that powers the stars.[Rh]

Figure 1: IVY MIKE Cloud[CTBTO]
(US Government)

The Philosopher's Bomb, Citations

Citations for The Philosopher's Bomb (Part 1, Part 2):

Friday, July 12, 2013

The Abo School

Figure 1: The Abo School Today[CLUI]
(Used Under Creative Commons License)

Can you make out what that sign says?

Tuesday, June 11, 2013

Peaceful Uses for Nuclear Explosions

The examples below are all from serious to semiserious sources - that is, sources where at least some thought was put into them beyond "what would make a cool picture".

Sunday, April 14, 2013

Propulsion Nucléaire Aéronautique?

So here's a mystery.   I was skimming an old AEC list of reactor proposals for article ideas, and I came across an entry for a reactor called "BRENDA", that was going to be built by the Societe Nationale D'Etudes et de Construction de Moteurs D'Aviation (SNECMA) and the Commissariat à l'Energie Atomique (CEA) in Cadarache, France.   The reactor was gas-cooled, used ceramic-clad enriched uranium oxide fuel, and would be moderated by beryllium oxide.   1 MWth power, 1300 F temperature.   Purpose: aircraft propulsion prototype.

Now that's certainly something.

Thursday, April 4, 2013

The Nuclear-Powered Swimsuit

And I'm not talking about the bikini.

In the mid to late 60s, the AEC studied the use of Pu-238 radioisotope heaters to provide heat for a Navy wetsuit:

Figure 1: Pu-238-heated Wetsuit

(Okay, yes, technically it's a wetsuit, not a swimsuit.   I thought swimsuit made a better title.)

Friday, March 29, 2013

Burning Metal, Part 2

Those Magnificent Men and their Atomic Machines

Burning Metal: The Los Alamos Molten Plutonium Reactor Experiment and the History of the Fast Breeder

Part II

With special thanks to Prof. R. M. Kiehn

Note on Notation
Money is going to be talked about a lot, but the value of the dollar has been different from year to year. In each case, unless otherwise specified, values will be given in the amount for the year in question, followed in parentheses by the equivalent value in 2011 dollars.

Change of Plans
But, as Los Alamos was preparing the third LAMPRE fuel loading, the nuclear energy landscape was changing.

In 1958 the Atomic Energy Commission (AEC) had set a target of making nuclear electricity cost-effective in regions with high fuel costs. In 1962, they decided they had just about reached that goal. Four private nuclear reactors and two joint public-private projects were producing power by 1962, and another ten were under construction, most of them Light Water Reactors (LWRs). In a landmark report to the president on civilian nuclear power in 1962, the AEC recommended that light water technology be handed over to the private sector. There were obviously further improvements to be made, but they would be evolutionary and incremental, and thus the domain of private enterprise rather than the AEC labs. Properly encouraged by the government, the light water reactor would be cost-competitive with coal and gas by the 1970s except in very low fuel cost areas. The AEC would focus instead on advanced reactor concepts, particularly breeders.

Tuesday, March 19, 2013

Burning Metal, Part 1

Those Magnificent Men and their Atomic Machines

Burning Metal: The Los Alamos Molten Plutonium Reactor Experiment and the History of the Fast Breeder

Part I

With special thanks to Prof. R. M. Kiehn

Note on Notation
Money is going to be talked about a lot, but the value of the dollar has been different from year to year. In each case, unless otherwise specified, values will be given in the amount for the year in question, followed in parentheses by the equivalent value in 2011 dollars.

In the Beginning
When the Atomic Energy Commission (AEC) was formed in 1947, it inherited from the Manhattan Project a sprawling empire of factories, test sites, laboratories, and development programs, organized around one purpose: the design and manufacturing of nuclear weapons. And for the first decade of its existence, that was the AEC's primary purpose as well. But the hopes of most of the scientists and engineers, and the citizens who paid their salaries, were not of weapons – they were of reactors, nuclear reactors to provide cheap, clean, abundant energy, energy to propel ships and planes, energy to free man from his age-old burden of labor, energy to bring permanent prosperity to the world.

In 1954, the AEC began to turn those hopes into reality. Although power reactor research had started at a low level before the AEC had even been formed, the requirements of national defense had limited most work to military applications such as naval propulsion. President Eisenhower's “Atoms for Peace” speech in December of 1953, along with growing pressure from the powerful Joint Committee on Atomic Energy, led to a steady expansion in the AEC's funding for civilian power reactor research. Developing a power reactor would be an immensely difficult, expensive, and time-consuming task. The AEC was well-armed for the challenge, with unprecedented public funding and the lion's share of the nation's talent in nuclear science and engineering. But what would a power reactor actually look like?

The reactors at Hanford, built during the war to make plutonium for bombs, were adequate for their task, but clearly unsuited to generating electrical power. And no one really knew what a power reactor would look like – after all, none had been built before.