The Nuclear City the Ice Is Giving Back

On January 22, 1961, Walter Cronkite stood in a parka under fluorescent light and walked CBS's prime-time audience through a small American town that had no sky [S3]. The episode of The Twentieth Century was called "City Under the Ice." To get the footage, Cronkite had ridden three days across the Greenland ice cap on a US Army sled train called a "heavy swing," in a broadcast directed by Norton Bloom [S3]. The town he was filming was Camp Century — a network of corrugated-steel trenches roofed and buried under snow, heated and lit by a portable pressurized-water reactor called the PM-2A [S6]. The Army had also flown in two teenagers: Danish Boy Scout Søren Gregersen, age 18, and his American counterpart Kent Goering, photographed grinning in front of crates of boxed-up reactor components [S4]. The boys overwintered for roughly six months starting in October 1960 [S4]. The whole production was wholesome enough to sell to a network audience and, more importantly, to Copenhagen.

What Cronkite did not film, because nobody had told him, was Project Iceworm — the classified parent program for which Camp Century was the working prototype [S2]. Iceworm envisioned roughly 4,000 kilometers of subglacial tunnels spread across about 52,000 square miles of the ice sheet, three times the area of Denmark, hosting 600 "Iceman" missiles — a modified two-stage Minuteman with a range near 3,300 miles — on rail-mounted launchers that could be shuffled around the network to defeat Soviet targeting [S2]. The strategic appeal was simple geography: a launch site buried in Greenland would sit closer to Moscow than any US arsenal outside Turkey [S2]. Historians who later combed the documents would describe Iceworm more cautiously than its brochure version — an Army concept study, never blessed by the Joint Chiefs — but Camp Century itself was very real, it was nuclear, and the concept could not be tested without it [S2].

The Army's engineering brief had a problem its senior planners did not consult on at the start, which is that ice does not behave like a solid. It flows continuously under its own weight; the Greenland sheet creeps seaward, and a tunnel trenched into it is a tunnel slowly being closed. Glaciologists arrived rather late on the project, and what they measured was unsettling. By the summer of 1962 — barely two years in — ice deformation had drooped the reactor-room ceiling badly enough that the Army had to physically jack it up about five feet, roughly 1.5 meters, to keep the ice off the reactor itself [S6]. The PM-2A was shut down in 1963 and removed in 1964 [S6]. The base was downgraded to summer-only operation the same year [S6]. By 1967, Camp Century was abandoned [S5].

What the Army left behind is the inventory you read in environmental complaints, not history books: about 200,000 liters of diesel fuel, around 24 million liters of untreated sewage frozen in a sump, PCB-contaminated building materials, and a poorly documented volume of low-level radioactive wastewater [S5]. The Atomic Heritage Foundation estimates the PM-2A produced roughly 47,000 gallons of low-level radwaste over its working life; only the reaction chamber itself was extracted at decommissioning and buried in an Idaho dump [S6]. Everything else — coolant infrastructure, contaminated water, the cumulative output of six years of human occupation — was left where it sat, on the comforting assumption that perpetual snowfall would entomb it forever [S5].

This is where Denmark enters with embarrassing timing. Denmark had banned nuclear weapons from its soil — Greenland included — in 1957 [S2]. The workaround had a postmark. On November 18, 1957, Danish Prime Minister H.C. Hansen wrote a letter to US Ambassador Val Petersen in which he very pointedly did not ask whether the United States intended to store nuclear weapons in Greenland [S2]. The US read the non-question as tacit consent and proceeded [S2]. That single letter is the entire diplomatic fig leaf for nuclear deployments at Thule Air Base and, by extension, for whatever else was happening at Camp Century [S2].

The cover held for almost forty years. Then, in 1995, the 1968 crash of a nuclear-armed B-52 near Thule re-erupted in Danish politics, driven in part by the investigative reporting of Danish journalist Poul Brink [S8]. On June 29, 1995, Denmark's foreign minister stood at a press conference and confidently announced there had never been atomic weapons in Greenland [S8]. About two weeks later he reversed himself in front of the same press corps: roughly 50 weapons had been there [S8]. The scandal acquired a name — "Thulegate" — and Parliament commissioned the Danish Foreign Policy Institute, DUPI, to produce a full inquiry [S2]. The DUPI report landed in January 1997 and pulled Project Iceworm into daylight alongside everything else [S2]. The cover was not blown by Washington declassifying anything voluntarily; it was pried open by an allied legislature that had spent three decades being lied to by its closest defense partner [S2][S8].

The second cover was the ice. In 2016, William Colgan and colleagues, then at York University in Toronto, published a paper in Geophysical Research Letters with the unbeatable title "The abandoned ice sheet base at Camp Century, Greenland, in a warming climate" [S1]. They modeled the site's local surface mass balance — snowfall gained minus snowmelt lost — under two IPCC emissions scenarios. Under RCP8.5, the business-as-usual trajectory, the Camp Century site flips from net accumulation to net ablation around 2100 [S1]. Under RCP4.5, closer to a Paris-aligned path, it stays buried [S1]. The paper is more careful than its headlines: it does not predict the waste will surface this century. It says the threshold past which remobilization becomes inevitable — on decadal-to-centennial scales — sits inside our policy window [S1].

That is the audit. The Army's plan assumed the ice would manage its mess forever; Colgan et al. quantified what "forever" actually means once the thermostat moves. The price of "perpetual snowfall" turns out to be about one century of bad emissions choices.

And then there is the question of who, exactly, handles the contents. Under Greenland's Self-Rule Act of 2009, environmental authority sits in Nuuk, not Copenhagen [S2]. The party now legally responsible for negotiating the cleanup of a US-built, Danish-permitted, ice-entombed Cold War nuclear installation is a government that did not exist when the camp was built — and that no one in 1957 thought to ask. The Indigenous Greenlandic population whose land hosted the project was a consultation skipped at every stage, from Hansen's evasive letter to Cronkite's parka.

A generation of Cold War infrastructure was built on an implicit promise that "forever" was a manageable engineering timescale, because forty or fifty years was the longest planning horizon a 1957 Army general had any practical reason to imagine. The ice was supposed to be the warranty. Camp Century is the first major piece of that warranty to come due. The deflection numbers were already inside the ceiling by 1962, and the rest of the contract — the diesel, the PCBs, the wastewater, the lie to Denmark — is being read back to us by a slow auditor that has, finally, started its work.