Peaceful nuclear explosions, that sounds like a contradiction in terms, especially in these times of heightened tension and nuclear sabre-rattling.
But there was time when back in the 50s, 60s and even up to the late 80s when the explosive power of a nuclear weapon was looked at in a very different way to how we generally think of them today. Of course, we now know a lot more about the downsides but back then, having a bigger bang for your buck was seen as the only way we could get some stuff done.
So instead of looking at ways to level cities, I thought we would look at what they proposed to do with some of those nuclear weapons for constructive purposes and maybe not to build cities but to connect them and do other things too.
Ever since the atomic bomb was created some have looked at it not only as the ultimate weapon but also as a tool to do things that were just not possible before.
If you look at it just from a size point of view you see the immediate advantage. This was the 108 tons of TNT that served as a test run before the Trinity atomic bomb test on the 16th of July 1945.
The Trinity bomb called “Gadget” was a metal sphere quite a bit smaller than the pile of approximately 3200 boxes of TNT and yet had the explosive power of 18,600 tons, about 172 times the explosive power of the original TNT test. Imagine how large the pile of TNT would be to match that and all the issues involved in transporting and handling it.
Since that time nuclear devices have been greatly optimized and now megaton devices could fit in the back of a small van.
On both sides of the iron curtain, ideas were put forward to use their enormous power to do in seconds what would take months, years otherwise or just not be possible at all by conventional means.
In the US this was called Project Plowshare, a name taken from a quote by the prophet Isaiah about converting weapons of war into goods for peace, “and they shall beat their swords into plowshares”
In the soviet union, a similar but larger program was initiated with the somewhat less enigmatic name “Nuclear Explosions for the National Economy”.
Project Plowshare came about as part of the 1957 Atoms for peace program which in itself was an attempt by the Eisenhower administration to try and balance the fears of continued nuclear armament with the peaceful use of uranium for future nuclear reactors and other nuclear technologies, and opening up the up until then-secret nuclear programs to other counties such as Israel and Pakistan by building nuclear power stations with them. Although ultimately the program was as much about containment of the Soviet threat as it was about spreading knowledge.
The idea was to get people used to the “friendly atom” and show that nuclear power didn’t always have to mean the death and destruction that had been seen in Hiroshima and Nagasaki.
Such applications would include large-scale excavations, seismological studies, prospect mining and stimulating gas and oil production using controlled nuclear explosions.
The first P.N.E’s or Peaceful Nuclear Explosions were due to be conducted in 1958 but were delayed by the test ban treaty between the United States and the Soviet Union which started in the same year. However, in 1961 it was broken by the Soviet Union when they resumed tests and the US restarted its test program shortly afterwards.
The first test was Project Gnome which occurred on the 10th December 1961, 40 km southeast of Carlsbad, New Mexico, in an area of salt and potash mines, along with oil and gas wells.
A 3.1 kiloton device was detonated at the end of a 340 meter horizontal shaft, 361 meters underground in a salt bed. The explosion created a cavity about 52m wide and almost 27m high with a floor of melted rock and salt.
Several experiments were to be carried out during the explosion including using the intense burst of neutrons generated to see if new radioactive isotopes could be created. More neutrons could be created in 100 microseconds of a nuclear explosion than in the most efficient reactors running for decades.
Others included seeing if electricity could be generated using the heat created and that remained in the rock. This is the reason why they chose a salt bed so water could be pumped through the molten salt to create steam that would rise up through boreholes to drive turbines and generate electricity, although the idea was sound in practice it didn’t work in reality because of other issues.
The explosion would also create big enough shock waves so that seismological studies covering most of the US could be undertaken to better understand its geology.
Just over six months after the test, a new tunnel was dug and scientists entered the nuclear-created cavern. The radiation level was low at only five milliroentgens, though after 6 months the temperature was still around 60C. They also found that the steam generation experiment had failed because part of the walls & roof had collapsed and the corresponding rocks had cooled most of the molten salt.
Soon, other experiments were undertaken such as Storax Sedan which was to explore cratering and earth-moving techniques. Here, a 104 Kiloton thermonuclear device, similar to a W56 high yield Minuteman one missile warhead was detonated 194 meters below the surface.
The blast lifted a dome of earth 90 meters above the surface before venting 3 seconds later. In all, it removed 11 million tons of earth and left the biggest man-made crater to date at 100m deep and 390m in diameter. The blast created seismic waves equivalent to 4.75 on the Richter scale.
It also created the largest amount of radioactive fallout of any single test in the US with the dust plumes rising to 16,000 ft and blown northeast and east before dropping on counties in Iowa, Nebraska, South Dakota and Illinois. If the blast had been done 3 years later in 1965 the radiation could have been about 100 times lower due to improvements in the design of the bomb.
The man-made crater later proved Eugene Shoemakers theory that the Barringer Crater was created by a meteor impact as very similar shocked rock samples were also found at the sedan crater and other nuclear ground tests.
The point of Sedan and other similar tests such as Project buggy which used five one-kiloton devices to dig a trench was to see if it would be possible to do earthmoving with nuclear explosions on a much bigger scale and in a much shorter timespan than using conventional methods.
Oil and gas stimulation was also big on the list of things that nuclear explosions were thought to be good at. The 1967 Project Gasbuggy in New Mexico was a test to shatter the sandstone rock in a gas field so that it could be more easily extracted. A 29-kiloton device was placed 1228 meters underground and the explosion created a 24-wide and 102-meter-high rubble chimney.
But when the gas was extracted it had an unacceptable level of radionuclides. Two further tests in project Rulison in 1969 and Project Rio Blanco in 1973 which turned out to be the final P.N.E test in the US were also found to be too radioactive. The economics were also questionable and found that even if all the gas were to be usable, after 25 years of production it would still only have paid for 15 to 40% of the extraction costs.
Whist the disadvantages gradually came to be known, that didn’t stop some of the ideas proposed in the earlier days seem by today’s standards somewhat mind-blowing in their audacity.
One was to build a new Panama canal upto 300 meters wide and 60 meters deep using multiple devices from the pacific to the Atlantic. If they used the shortest route which would be about 40 miles or 65km it was reckoned that about 325 one megaton devices would be required and it would take about 2-1/2 years to complete if worked 24/7.
Another idea considered for Project Carryall from 1963 – 1966, which was to create part of a new interstate highway and rail line which is now the I-40 across the Mojave desert and through the Bristol mountains using a similar technique of multiple bombs used at once to dig trenches through the rock. Though again this would have been subject to safety concerns and radiation fallout and was eventually dropped due to the cost of developing a clean enough bombs.
Project Chariot in 1958 would create an artificial harbour at Cape Thompson on the North Slope of Alaska and was championed by Edward Teller, the father of the Hydrogen bomb as well as many local politicians, newspapers and other groups and was seen as important economic development for the state.
It would have used five thermonuclear devices exploded in sequence to create the harbour.
This was eventually called off as opposition from the local people and scientists grew and evidence came in that worldwide radioactive material was travelling faster up the food chain in the arctic than in other areas of the world and that any economic benefits would be outweighed by the cost of the operation.
In 1963 The Lawrence Livermore National Laboratory proposed building an alternative to the Suez canal. This would have used 520 2 megaton devices to carve a 160-mile or 257-km path through the Negev desert in Israel from the Mediterranean to the Red sea.
However, as the proposal stated it, would have been difficult to forecast the economic feasibility not to mention the political and radioactive fallout from and on the surrounding Arab countries.
As time went by and the issues became more apparent, the 15-year Project Plowshare was gradually defunded until 1977 when it was terminated due to public opposition after 11 years and 26 tests.
However, whist public opinion may have halted progress in the US, in the Soviet Union public opinion was of little concern compared to the perceived greater good and national security, so their PNE program was much bigger and lasted much longer, consisting of 156 tests from 1965 to 1989.
Because of this, their scope was wider and did achieve some notable successes, especially in extinguishing runaway gas well fires.
On the 1st December 1963, well No 11 in the Urta-Bulak gas field caught fire destroying the platform. The well was drilled to 2400 meters into a thick gas-bearing layer which came out of the wellhead at a pressure of 300 atmospheres or 4400 psi.
The broken wellhead focused the burning gas into a giant roman candle over 120 meters high and consumed 12 million cubic meters of gas per day, enough to satisfy a large city.
The Soviets tried everything to cap the well but nothing worked. So in the end they decided to use a nuclear device to shock the area around the wellbore to collapse it and cut off the gas flow.
They dug a new wellbore to a depth of about 1500 meters and within 40 meters of the original, then a 30 kiloton device was lowered into place and the wellbore was backfilled with concrete.
On the 30th of Sept 1966, nearly 3 years after to initial blowout the device was detonated and within 23 seconds the flow of gas dwindled to nothing. A few months later a 47 kiloton device successfully stopped another high-pressure blowout at the nearby Pramuk gas field.
Following the success of 4 out of 5 gas plugging operations, although some did fail again later, when the deepwater horizon oil spill occurred in 2010, the use of a nuclear device was suggested to collapse the wellbore to cut off the flow of oil.
In the end, the idea was ruled out because of the fear of radiation and preparing for it would take at least 6 months. That and the explosion which would need at least 30 kilotons could fracture the sea bed and create even more leaks.
The soviets did use nuclear explosions for other things such as creating underground storage for toxic waste and storage of gas as well as crush ore in open cast mines to make it easier to extract metals and alike. Both oil and gas stimulation was done with 25 nuclear blasts though little is known about if the resultant gas became radioactive as in the US tests.
In a near copy of the US Project sedan, in 1965 the Soviets exploded a 140 kiloton device at the edge of the Semipalatinsk Test Site in the dry bed of the Chargen river. This created a crater 100m deep and 408m wide to capture the water when the high spring flow occurred and create an artificial lake.
But like the sedan test it also created a lot of fallout which ended up as far away as Japan.
Although at the time when tests were done afterwards, it was “said” to be perfectly safe to swim in the lake and irrigate crops with the water, that propaganda could be taken with a pinch of radioactive salt and today it would be considered too dangerous to use.
The last Soviet PNE was in Sept 1988 and was a part of a seismic program for geological exploration. The program was shut down as part of Mikhail Gorbachev’s nuclear disarmament initiative.
In general, the use of nuclear devices to provide a replacement for conventional explosives ran into many difficulties, not least the release of radionuclides and the cost of developing the devices with low fallout was also prohibitive.
The one area where it did prove useful was in putting out large fountains and fires on natural gas deposits and this is an area where proponents in modern-day Russia say that it is still the choice of last resort should these instances occur again in the future.