The Nuclear Reactor That America Buried at the Bottom of the World
Workers on the western slope of Mount Erebus spent the early 1970s taking a nuclear reactor apart by hand. They cut the four-component plant into sections, lifted the steel tanks out of the gravel they had been embedded in, and discovered something that turned a routine decommissioning into a decade-long emergency: the volcanic ground itself had gone radioactive. Effluent had been seeping down a drain pipe into the soil for years. So the U.S. Navy did the only thing the Antarctic Treaty allowed. It dug a hole roughly 9,000 cubic meters wide, scooped out the contaminated earth, and loaded it onto supply ships bound for California and Georgia — routing the radioactive cargo, in a final irony, through nuclear-free New Zealand. In total, around 12,000 tons of irradiated gravel and soil left the continent. The Americans had come to the last unspoiled place on the planet, and when they left that corner of it, they had to take the mountain with them.
The reactor was called PM-3A, and almost no one remembers it. Its story is the story of McMurdo Station in miniature: a monument to the idea that human ingenuity could conquer the ice, undone by the simple fact that the ice does not forgive mistakes.
McMurdo is the largest settlement on Antarctica, and that single fact contains its central contradiction. Humanity came to the most protected wilderness on Earth — a continent set aside by treaty for peace and science, off-limits to weapons and mining and territorial war — and proceeded to build a town there. A town with all the things towns have. Power plants and waste problems. Hierarchies and isolation. Boredom, drink, and the darker appetites that follow people into small rooms at the end of the world. McMurdo was meant to be a clean experiment in pure knowledge. It became a mirror.
How Antarctica Became a Cold War Chessboard
The world had never settled who owned Antarctica, and by the 1950s that question had become dangerous. Seven nations had drawn pie-slice claims across the continent, several of them overlapping, none of them recognized by everyone else. Britain, Argentina, and Chile all insisted on the same wedge of the Antarctic Peninsula. The United States and the Soviet Union, the two powers that mattered most, had filed no claims at all — and reserved the right to file them later. A frozen continent the size of the United States and Mexico combined sat unclaimed, unmilitarized, and increasingly contested at the precise moment the Cold War was hardening into a global standoff.
The solution arrived dressed as science. The International Geophysical Year, running from July 1957 to December 1958, was a coordinated global research push, and Antarctica was its showpiece. Twelve nations agreed to build research stations across the continent and, for the duration, to set their territorial quarrels aside. The arrangement worked so well that it was made permanent. The Antarctic Treaty, signed in 1959 and in force by 1961, froze all territorial claims, banned military activity and nuclear weapons, and dedicated the entire continent to peaceful research. It remains one of the most successful international agreements ever written.
Operation Deep Freeze and the Hut Beside the Base
The United States needed a foothold, and it chose Ross Island. American icebreakers arrived in 1955 under Operation Deep Freeze, the military logistics campaign that would supply the U.S. Antarctic effort for decades, and began throwing up a base on the bare volcanic rock of Hut Point Peninsula. They first called it the Williams Air Operating Facility. By December 1955 it had a new name, borrowed from a British naval officer named Archibald McMurdo who had charted the sound aboard HMS Terror in 1841 and never set foot on the continent that would carry his name forever.
The Americans built their base a short walk from a far older structure. Robert Falcon Scott’s men had raised a hut at Hut Point in 1902 during the Discovery expedition, and Scott’s later base at Cape Evans still stood across the island, its shelves stacked with seal blubber and tinned food, frozen exactly as the doomed explorers had left it. The men of Operation Deep Freeze were laying down generators and fuel depots within sight of the relics of an era when reaching this coast at all was a feat that killed people. The contrast was lost on no one. Half a century separated the Cape Evans hut from the new airstrip, and in that half century Antarctica had gone from a place men died trying to reach to a place the United States Navy was wiring for electricity.
Nukey Poo: The Nuclear Reactor That Poisoned the Antarctic Ice
The Navy decided the answer to McMurdo’s energy problem was an atom. In the late 1950s, nuclear power carried a futuristic shine — clean, compact, the obvious technology for the century ahead. Diesel had to be hauled across the most hostile ocean on the planet and burned by the thousands of gallons a day, and every drop arrived by ship through pack ice that could trap a convoy for weeks. A reactor promised to end the dependence. It promised heat, electricity, and fresh water from a single core no larger than an oil drum. To a military planning a permanent presence on the ice, it sounded like the future.
Why the U.S. Navy Brought an Atom to Antarctica
PM-3A stood for “portable, medium-power,” the third in a line of compact military reactors. It was shipped to McMurdo in sea crates over the summer of 1961 and assembled on the slope of Mount Erebus. The cold imposed a strange engineering compromise from the start: concrete will not cure in sub-zero temperatures, so the reactor could not be encased in the usual protective shell. Instead, its four main components sat in steel tanks embedded in gravel and wrapped in a lead shield. A crew of 25 men from the Naval Facilities Engineering Command ran it. The reactor went critical on March 3, 1962, and began feeding power to the station that July. It generated 1.8 megawatts and reportedly replaced the need for 1,500 gallons of oil a day. The crew, with the gallows affection sailors reserve for machines that try to kill them, named it Nukey Poo.
The name was earned fast.
Ten Years of Malfunctions, Leaks, and Quiet Failure
Trouble started in the reactor’s first year. A hydrogen fire broke out in the tanks, knocking the plant offline for eight weeks and forcing McMurdo back onto emergency diesel — the very thing the reactor was supposed to render obsolete. The fire was the opening act. Over its operational life, PM-3A logged 438 documented malfunctions, an average of roughly 56 a year, more than one a week, every week, for a decade. Components cracked three separate times. A persistent fault sent slightly radioactive effluent trickling down a drain pipe and into the volcanic soil, year after year, in a slow contamination no one fully tracked at the time.
The end came from corrosion. During a routine inspection, technicians found wet insulation and feared chloride stress corrosion was eating into the reactor’s lining — the kind of flaw that precedes a serious leak. Within roughly a month of the discovery, the Navy made its decision. In September 1972, after ten years and 438 things going wrong, Nukey Poo was shut down for good. The military had already abandoned its dream of seeding reactors across its remote outposts; the Antarctic experiment had proven the technology was too expensive, too fragile, and too dirty for the places that needed it most.
Shipping the Contaminated Mountain Back to America
Decommissioning a reactor normally means entombing it in concrete and walking away. The Antarctic Treaty made that illegal — nothing radioactive could be left behind, and nothing could be dumped at sea. So the Navy faced a problem no one had solved before: how to make a nuclear reactor, and the ground it had poisoned, completely disappear from a continent.
The answer was brute removal. Crews cut the plant into transportable pieces and crated it for shipment to disposal sites in the United States. Then they turned to the earth. Testing revealed the gravel and soil around the tanks had absorbed enough radiation to require excavation, and the Navy dug it out — eventually around 12,000 tons of irradiated rock and soil, hauled onto Military Sealift Command vessels and carried north. Some of it ended up at Port Hueneme Naval Base in California, where it was reportedly mixed into asphalt pavement. The site at McMurdo was dug down roughly 9,000 cubic meters and backfilled, and the work of fully clearing it dragged on until 1979. The cleanup predated Antarctica’s modern environmental rules by two decades and forced the United States to invent soil-contamination standards on the fly, because no one had ever needed them at the bottom of the world before.
The human cost trailed the cargo home. New Zealand soldiers who had loaded the contaminated soil in the late 1970s later feared they had been exposed; one veteran, a cargo handler named Paul Williscroft, recalled being ordered in early 1979 to load an American ship taking soil away from the shuttered plant. American servicemen who had worked at McMurdo died of cancers their families linked to the reactor, and decades later federal hearings would examine radiation exposure among McMurdo Navy veterans — only for investigators to find that years of exposure records had been lost. The reactor that was supposed to free McMurdo from its fuel ships left behind a paper trail of malfunctions, a hole in a volcano, and a generation of men who spent the rest of their lives wondering what the ice had given them.
Nukey Poo was not the only polar reactor the Cold War buried and abandoned. The United States had already tried the same trick in the Arctic, planting a portable reactor inside a secret tunnel city under the Greenland ice sheet — a project that ended the same way, with the reactor pulled out and the dream of a nuclear-powered polar empire quietly written off. Today a small bronze plaque at McMurdo commemorates the first and only nuclear reactor ever to operate in Antarctica. It is the politest possible memorial to one of the messiest things the United States ever did on the continent.
Life and Death on the Ice
McMurdo grew anyway. The reactor failed, the diesel generators came back, and the base kept expanding into the haphazard sprawl it is today — more than a hundred buildings scattered across 164 acres of frozen volcanic dirt, a town with a fire station, a chapel, a store, a post office, a hair salon, a 24-hour coffee house, and two bars named Gallagher’s and Southern Exposure. In the height of the austral summer it holds well over a thousand people: scientists, but mostly the cooks, mechanics, janitors, electricians, and IT workers who keep a small city running on a continent that wants nothing alive on it. The place looks less like a research outpost than a mining town that wandered onto the wrong planet.
Winter-Over: Months of Darkness and the Psychology of Isolation
Then the sun goes down and does not come back. From around April to September the polar night swallows McMurdo whole, and the population collapses to fewer than two hundred people sealed inside the dark. There are no flights in or out for months. Temperatures fall toward minus 58 Fahrenheit, and a winter storm can drive the wind chill near minus 85 — cold enough that crossing the gap between two buildings becomes a calculated risk. The people who stay are the “winter-overs,” and they spend the long night in a closed loop of the same faces, the same corridors, the same recycled air.
The isolation does things to people. Researchers who study polar psychology describe a syndrome of irritability, insomnia, depression, and cognitive fog that sets in during the dark months, sometimes called “winter-over syndrome.” The first women did not winter over at McMurdo until 1974, when biologist Mary Alice McWhinnie and Sister Mary Odile Cahoon spent April through October on the ice — a measure of how long the base remained an all-male enclosure, and how slowly that changed. For most of its history McMurdo was a place where a few hundred people, overwhelmingly men, were locked together in the cold and the dark with no exit and no daylight, and told to hold it together until the planes returned in August.
The Deaths McMurdo Doesn’t Advertise
People die at McMurdo. The continent kills slowly through cold and exposure and quickly through accident, and the base’s history is dotted with both. A 1991 fire destroyed the Old Chapel, a Quonset hut being used to store musical instruments, while a band played in the club across the street and a winter-over crew fought the flames in a wind chill near minus 85. The buildings burn easily in the dry polar air, and firefighting in a place where water freezes in the hose is a special kind of nightmare.
The worst recent loss came in December 2018. Two fire technicians — contractors performing preventive maintenance on a fire-suppression system at a remote generator building serving a radio transmitter — were found unconscious on the floor by a helicopter pilot who saw smoke and landed to investigate. One was pronounced dead at the scene. The other died after being flown to the McMurdo clinic. They had been asphyxiated while servicing the very system meant to keep others safe. The men were employees of a subcontractor, two of the thousands of workers who do the unglamorous labor that lets the science happen, and their deaths were investigated and absorbed into the long quiet ledger of people the ice has taken. McMurdo is a place of discovery. It is also a workplace, and like all workplaces in extreme environments, it occasionally kills the people running it.
The Town’s Darkest Open Secret
McMurdo’s most disturbing crisis has nothing to do with the cold. In 2022, the National Science Foundation released a report it had commissioned the year before, and it landed like a detonation. Built on more than 80 interviews and a survey of 880 current and recent workers, the report reached a conclusion the agency could not soften: sexual harassment, stalking, and sexual assault were ongoing, continuing problems across the U.S. Antarctic Program — and McMurdo, as the largest station, was named the worst of them.
The numbers were grim. Among women surveyed, 59 percent reported personally experiencing or witnessing sexual assault or harassment, and 72 percent agreed it was a problem in the program. Ninety-five percent of respondents knew someone who had been assaulted or harassed. The details were worse than the statistics. On her first day on the ice, one woman was warned to stay away from a particular building “unless you wanted to be raped.” Another said harassment was simply a fact of life in Antarctica, “just like the fact that Antarctica is cold and the wind blows.” One interviewee called McMurdo a “training ground for bad behavior” that set the tone for the entire continent.
The isolation that makes McMurdo extraordinary is exactly what makes it dangerous. A victim cannot leave for weeks or months. In deep field camps, a person can be trapped working alongside their harasser with no way to call for help and nowhere to go. And the reporting culture, workers told investigators, punished the wrong people: “the number one thing I heard was ‘don’t report it or you will go home and be blacklisted from the program.’” One mechanic, Liz Monahon, told the Associated Press that after a man threatened her life and her appeals to human resources went nowhere, she started carrying a hammer with her for protection — ready, she said, to start swinging if he came near.
The fallout was slow but real. In late 2022 the NSF stopped serving alcohol at McMurdo’s bars, though workers could still buy a weekly ration. In 2023, the agency’s inspector general sent criminal investigators to the station for the first time and appointed a dedicated sexual-assault-prevention official. In 2024, a U.S. House committee concluded after a two-year investigation that the NSF had failed to protect its Antarctic workers and had been lax in overseeing the contractors who employ most of them. The cleanest, most idealistic enterprise the United States runs — pure science at the end of the Earth — turned out to have carried one of humanity’s oldest predations along with the cargo.
McMurdo Today: Cleanup, Rebuilding, and the Ethics of the Ice
McMurdo in the 2020s is a town confronting its own decay. The base grew without a plan for sixty years, and most of its structures are now at or past the end of their design lives. The answer is the Antarctic Infrastructure Modernization for Science project — AIMS — a decade-long, federally funded rebuild meant to collapse the station’s sprawl of more than a hundred aging buildings down to roughly sixteen, including a new central facility, a 285-bed dormitory, and consolidated workshops. The first new structures are rising as the old ones come down; a replacement dormitory has been under construction with completion expected in 2026. The Navy reactor is long gone, but the cleanup mindset endures — the entire base is being rationalized, insulated, and made to leave a smaller mark on the rock it sits on.
Even resupply has become a battle against the changing continent. McMurdo was long served by an ice pier in Winter Quarters Bay, but warming seas have made the ice unreliable, and the pier has failed five times in a decade. The United States is now building a permanent floating barge pier to replace it — a quiet acknowledgment that the frozen world the base was designed for is melting underneath it.
Visiting the Edge of the World
McMurdo is not a tourist destination, and it never will be. There is no commercial way in. The station exists for the United States Antarctic Program, and reaching it requires a job, a research grant, or an invitation, followed by a flight from Christchurch, New Zealand — roughly 2,400 miles across the Southern Ocean — onto a sea-ice or snow runway in conditions that can ground aircraft for weeks. The handful of people who arrive each year come to work, not to sightsee.
For those who do reach it, the historic huts of Scott and Shackleton still stand nearby on Ross Island, preserved as some of the most haunting relics of the heroic age of exploration, accessible only to permit holders under strict conservation rules. Mount Erebus smokes on the horizon, one of the few continuously active volcanoes on the planet, the same slope that once held a leaking reactor. The bronze plaque marking Nukey Poo’s old site is a modest thing, easy to walk past.
What McMurdo offers is not beauty in the postcard sense but a particular kind of clarity. It is the place where the cleanest intentions humanity ever wrote into law — a continent for peace, for science, for no one — collided with the ordinary truth of what people are. The reactor leaked. The base sprawled. The dark months bred their own cruelties. And still the science gets done, the ice cores get drilled, the climate record gets read out of the snow. McMurdo is the proof that there is no empty place left on Earth where we arrive without bringing ourselves. The wind blows, the sun goes down for half the year, and at the bottom of the world the most human settlement on the planet keeps the lights on.
Frequently Asked Questions
Why was there a nuclear reactor at McMurdo Station?
The U.S. Navy installed the PM-3A reactor, nicknamed “Nukey Poo,” in 1962 to reduce McMurdo’s dependence on diesel fuel, which had to be shipped across the Southern Ocean by the thousands of gallons. The reactor was meant to supply electricity, heat, and desalinated water from a single compact core. It proved so unreliable — logging 438 documented malfunctions over ten years — that the Navy shut it down in 1972, and the technology was never used at America’s other remote bases.
What happened to the contaminated soil at McMurdo?
After the reactor was decommissioned, the Navy discovered that years of radioactive effluent had contaminated the volcanic soil beneath the plant. Because the Antarctic Treaty forbids leaving radioactive material on the continent or dumping it at sea, around 12,000 tons of irradiated rock and soil were excavated and shipped to the United States, with some routed through nuclear-free New Zealand and ultimately disposed of at sites in California and Georgia. The full cleanup was not completed until 1979.
How many people live at McMurdo Station?
The population is highly seasonal. During the austral summer, from roughly October to February, McMurdo holds well over a thousand people and can support up to about 1,200. During the winter months, when the sun disappears and flights stop, the population drops to fewer than 200 “winter-over” residents who remain sealed in for months at a time.
Is McMurdo Station safe for workers?
A 2022 National Science Foundation report found that sexual harassment, stalking, and sexual assault were ongoing problems across the U.S. Antarctic Program, with McMurdo named as the worst location. Fifty-nine percent of women surveyed reported experiencing or witnessing such behavior. The isolation of the base, where workers cannot easily leave, compounds the danger. Since then the NSF has restricted alcohol, sent criminal investigators, and faced a critical congressional review of its oversight.
Can tourists visit McMurdo Station?
No. McMurdo is a working research and logistics base operated by the U.S. Antarctic Program, and there is no commercial access. Reaching it requires employment, a research grant, or an official invitation, plus a military or contracted flight from Christchurch, New Zealand. The nearby historic huts of Scott and Shackleton can be visited only by permit holders under strict conservation rules.
Why is McMurdo built on volcanic rock?
McMurdo sits on the bare volcanic ground of Hut Point Peninsula on Ross Island, near the active volcano Mount Erebus. The exposed rock provides a stable, ice-free foundation and a natural harbor deep enough for resupply ships, which is why both early explorers and the modern station chose the location. It is one of the southernmost points of solid, ice-free ground on the continent.
Sources
The Story of Nukey Poo — Bulletin of the Atomic Scientists (1978)
The Rise and Fall of ‘Nukey Poo’: Lessons for Today’s Nuclear World — Naval Historical Society of Australia (2024)
Remembering Antarctica’s Nuclear Past with ‘Nukey Poo’ — The Conversation (2018)
Sexual Assault and Harassment Prevention and Response Report — National Science Foundation (2022)
Sexual Harassment and Assault Plague U.S. Research Bases in Antarctica — National Public Radio (2022)
Women Report Rampant Sexual Harassment at Antarctica’s McMurdo Research Station — Smithsonian Magazine / Associated Press (2023)
House Science Panel Says an ‘Absent’ NSF Failed to Protect Antarctic Workers — Science / AAAS (2024)
Antarctic Infrastructure Modernization for Science (AIMS) Project Documentation — National Science Foundation, U.S. Antarctic Program (2024)
McMurdo Station — Encyclopaedia Britannica (2024)
Two Technicians Killed at McMurdo Station — Associated Press (2018)
Kiwis Fear Cancer After Working Near Leaky US Nuclear Reactor in Antarctica — Stuff / Will Harvie (2018)
The Antarctic Treaty — Secretariat of the Antarctic Treaty (1959)
