U.S. Lights New Atomic Pile for Peace
April 1949 Popular Science

April 1949 Popular Science [Table of Contents] Wax nostalgic about and learn from the history of early electronics. See articles from Popular Science, published 1872-2021. All copyrights hereby acknowledged.

A Wikipedia on the history of nuclear power shows a photo of the first light bulbs ever lit by electricity generated by nuclear power, at EBR-1 at Argonne National Laboratory-West, December 20, 1951. That was two years after this "U.S. Lights New Atomic Pile for Peace" article in Popular Science magazine, which discusses progress at the Brookhaven National Laboratory, located in New York state. It opened in 1947. Much public excitement - and fear - was fomented over the use of nuclear energy, which had just four years earlier been used to bring an end to World War II through its awesome level of concentrated destructiveness, for peaceful uses like generating electrical power and for medicine. During the postwar era, many such articles, which some considered propaganda, were published, television shows aired, and movies produced in attempts to turn the public into pro- or anti- nuclear power activists. The "anti's" have done a pretty good scaring everyone to the point where rather than benefitting from the very "green" aspects of nuclear power (which would have been continually improving in technology), they instead are accepting monstrous installations of solar arrays, wind turbine farms, and other impractical technologies. Their cost to society, economies, and the environment are rarely reported honestly.

U.S. Lights New Atomic Pile for Peace

Popular Science shows you the innards of Brookhaven's nuclear furnace.

By Martin Mann

Sometime this summer a young man in a sports jacket will twist a few knobs with his eyes fixed on a Geiger counter, then turn and say, "It's critical." The atomic pile at Brookhaven National Laboratory then will be running under its own "steam."

This, the fourteenth furnace ever built to release and control the terrifying forces in the heart of the atom, will be the world's most powerful air-cooled pile. Only the water-cooled giants that manufacture plutonium for bombs at Hanford, Wash., out-range it in the U. S. Brookhaven's pile, however, will not make fuel for bombs, and may not produce any usable power. Instead, it will produce more wrinkles in men's brows - by increasing their knowledge.

Drive out Long Island's Jericho Turnpike 65 miles from New York City to the edge of the duck- and potato-farm country, then turn off at an inconspicuous sign marked "Brookhaven National Laboratory," and you will quickly spot a big, striped smokestack. It towers above a group of modest frame and concrete-block buildings that house the laboratory. The smokestack and the most imposing buildings are on the side of Rutherford Hill - named for Sir Ernest Rutherford, the British physicist who laid the foundations of nuclear theory.

The biggest building, a light brick structure six stories tall, with two gigantic, green-glassed bay windows, contains the pile. It has two lower wings for laboratories especially designed and equipped for workers with radioactive chemicals. And there is a detached building in the rear for the "hottest" laboratory, where experiments with intensely radioactive substances can be conducted by remote control. Nearby are the fan house, cooling towers, and stack.

No smoke will ever belch from the stack of this plant (PS, Nov. '48, p. 108). Instead it will release the cooling air that gigantic fans will whirl through the pile at a rate of many tons a minute. And this radioactive air will come out of the stack only when atmospheric conditions are such that it will be safely dispersed.

To go inside and see the pile itself, you need a "Q" clearance from the Atomic Energy Commission. The drawing on pages 122 and 123, however, shows you even more than would meet your eye : if you walked into the huge room containing the beige-painted concrete cube, about 40 feet on a side. Only three faces and the top are exposed. The back - not visible in the drawing - is where the uranium is put in. Because this pile "burns" so fast, a new charge will be needed at least every few years.

The three visible sides bristle with balconies, tubes, rods, switchboxes, and wiring. On the two parallel working faces are seven rows of small windows. Most of these are about four inches square. These windows go directly into the hot heart of the pile. Material can be inserted through them for irradiation inside the pile. And beams of neutrons, gamma rays, and all the other kinds of particles and waves can be let out of the pile through them. The windows extend all the way through to both faces, in case something placed inside has to he pushed out. Balconies sticking out from the faces of the pile give easy access to the upper rows of windows.

The north face of the pile (directly in front of you in the drawing) has a system of pneumatic tubes that reach into its center. These tubes are like those used in department stores to relay orders and make change. Here they will be used to shoot material into the pile to be bombarded with neutrons, and to whisk back the newly made isotopes. This arrangement permits study of short-lived isotopes, the ones that lose their radioactivity and change into something else in a few minutes or even seconds.

Some of the pneumatic tubes end at the pile face itself; others extend under the floor into nearby laboratories, so that the isotopes can be delivered straight to a scientist's workbench. It is even possible to connect the tubes directly to experimental equipment, so that a fresh radioisotope will pop right into a test tube or flask and immediately become part of an experiment.

On the same face of the pile you can also see the lattice - the ends of the openings that hold the uranium rods. These openings extend through the pile. The actual loading and unloading, however, always will be done from the opposite side.

One other opening in the south face is a large one, about a foot square, set in the very center. It allows a beam of neutrons to shoot out of the pile and down a corridor built for it through the adjacent laboratories and offices. Such a beam, 60 feet long, may help experimenters determine the extent to which distance affects the ability of various materials to absorb neutrons.

When the pile is cut off, scientists may also work on top of it. The top is made up of 4-ft. square concrete blocks that can be lifted out to make openings wherever the researchers want them. These large openings do not give access to the center of the pile, but merely expose its outer graphite shell. A lot of slow-moving neutrons leak through the shell (this "leakage flux" is about 1/50 as intense as the neutron beams from the heart of the pile) and can be used for experiments in big apparatus placed over the opening in the shield.

Tunnels for Tests with Animals

As a visitor to the pile room, you might also notice trapdoors in the floor. They lead to two tunnels that pass directly underneath the pile. In each tunnel there is a small car, pulled by motor-driven chains, that can be moved back and forth through the tunnel and stopped under an opening in the pile's bottom shield. The smaller car is for exposing instruments to the full blast of radiation from the pile. The larger one can carry animals as big as chimpanzees.

Animal experiments may reveal a cure for radiation sickness - whether caused by an accident or a bomb - and may also tell much about cancer, heredity, and the other biological mysteries. This is the first installation permitting studies with animals of near-human size and complexity. Previous work at Oak Ridge has been limited mainly to rats and rabbits.

Inside the concrete cube there are 60,000 pieces of graphite, which resembles the lead in your pencil but is nearly 100 percent pure. There are 2,600 different sizes and shapes of these pieces. Putting them together was like assembling a colossal Chinese puzzle. These thousands of "bricks" were made so accurately that they fit together to form an almost airtight mass without needing cement or mortar between their joints.

Inside this graphite block, within the concrete cube, is a maze of channels. Aluminum cans containing the long rods of uranium that make the pile powerful fit into some of them. Others are for the cadmium rods, which the operators can slide in and out like pistons to regulate the rapidity with which the invisible neutrons split the invisible atoms of uranium. Still others are the ducts through which the air to cool the pile circulates.

Fuel Is a Mixture of Isotopes

The uranium in the Brookhaven pile is "natural" material. It is highly purified, but is still a mixture of the three isotopes - U-234, U-235, and U-238. Only the U-235 atoms fission (split), and they are barely 0.7 per-cent of the total.

Nevertheless, the Brookhaven pile will run at fairly high power - unofficially estimated at about 5,000 kilowatts or more. Most of this power will be wasted, but about 1,500 kilowatts could be converted into electricity to help run the cooling fans. (Outside power would still be needed for the fans, however, since they draw much more than 1,500 kilowatts.) If this is done, the Brookhaven pile will become the first in America to generate useful electric power.

But the new pile will not produce anything like 5,000 kilowatts immediately. At first its power output will be nearer zero. For it will be "warmed up" slowly and will not be operated at full power until, possibly, sometime in July. This slow rise in output will give the engineers a rare opportunity to learn things that cannot be learned after a pile has its full load of fuel. During this build-up period, scientists will study the pile closely, watching the neutron production in various sections, the changes in the graphite bricks, the effects or weather conditions, the way the control changes with increasing power, and how fission products build up in various parts of the pile.

By next fall the research program for which the pile is being built should be running full blast. It will cover nearly every field of science - physics, chemistry, biology, medicine, and all the rest. But much of it will be concentrated on chemical and metallurgical problems related to materials used in piles. For materials are the main stumbling block to atomic progress now. If the engineers had the right materials, they could design good nuclear engines for power plants, rockets, airplanes, or warships in a jiffy.

Will Gold Shield Atomic Engines?

Shielding is one of the toughest problems. The shield on the Brookhaven pile - the part you can see - is made of a special, secret kind of concrete at least six feet thick. You can't put that heavy a shield in an atomic rocket, or even a battleship. But what can you use that's lighter? Professor Walter C. Whitman, head of the chemical engineering department at M.I.T., recently made a study of light shielding materials for the Atomic Energy Commission. His report: the cheapest shield now available would be 24-karat gold!

Another big problem is finding structural materials to use inside an atomic engine. Most ordinary things either react badly with neutrons or melt under the high temperatures. Steel absorbs neutrons so fast that it would stop a pile completely. For a while, the unusual metal titanium (now used in white paint) looked like a good bet, but it has not lived up to expectations. Zirconium might work, but it is always accompanied by hafnium, which is bad. Rubidium and caesium, two other possibilities, are too scarce.

Then there is the ash headache. When a U-235 atom fissions, it breaks into two pieces - two new elements each weighing somewhere around half as much as uranium. (These fission products are not always the same elements, but may be any of the 24 that range from selenium to lanthanum in the periodic table.) The fission products will not fission themselves. Worse than that, they absorb neutrons, reducing the power of the pile. Nucleonics experts call this process "poisoning the pile."

The poisons, or nuclear ashes, have to be taken out after the pile has operated a while. But mixed in with the ashes is a lot of good, fissionable uranium far too valuable to throwaway. As Sumner Pike, one of the members of the AEC, once said, a pile is like an inefficient coal furnace that lets unburned coal fall into the ash pit. You can shake the ashes, get that coal out, and put it back in the furnace. But the nuclear "ashes" must be shaken at least 10 times to get all the uranium out. These ashes also contain plutonium, the fissionable stuff in bombs, and other materials so radioactive that you dare not get too close to them even if you wear an asbestos suit.

So ways must be found to reduce the poisoning effect of the fission products, so that the ashes won't have to be shaken so many times. More efficient and cheaper methods of doing the shaking must be learned, too. Present estimates indicate that a plant for shaking an atomic ash barrel would cost as much as the atomic power plant it would accompany. And somebody has to figure out an easy way to get rid of the left-over radioactive "garbage," now mostly buried in huge underground tanks.

The Brookhaven experimenters may not answer these questions - or even attack them directly. Brookhaven's scientists merely seek facts, any kind of facts, not just those dealing with power plants and rocket motors. Yet the basic facts of nature are the bricks out of which some men, somewhere, sometime, will build power plants and rocket motors.

Posted April 10, 2024