Navigating nuclear waste: Creative solutions and future challenges

What happens to a nuclear-powered ship when, after several decades of service, it becomes outdated and is decommissioned? The United States has developed a special procedure called the Ship-Submarine Recycling Program (SRP) for the safe dismantling of nuclear-powered vessels.

Over 100 American nuclear submarines, as well as aircraft carriers like the ex-Enterprise, have undergone dismantling. Decommissioned ships retain their names during this process but are prefixed with "ex-". Likely in 2026, the first Nimitz-class aircraft carrier, USS Nimitz, will also be scrapped, possibly marking its final voyage with the US Navy.

While the hull is scrapped like any other vessel, nuclear-powered ships must be stripped of their nuclear fuel and reactor modules beforehand.

The fuel is transported to the Naval Reactors Facility in Idaho, and the propulsion elements are carried by train to the Hanford site in Washington state, where they are placed in a nuclear dumpsite called Trench 94.

To ensure the safe transport of potentially dangerous ship parts, a special transport system called Atlas was built. This 16-axle platform, approved for ordinary railroad tracks, can carry loads exceeding 220 tons, while monitoring radiation levels along the entire route.

Atlas faces a significant challenge, as the U.S. Department of Energy estimates that by 2060, it will need to transport up to 154,000 tons of spent nuclear fuel and radioactive materials. Where should such massive amounts of hazardous waste be stored?

For nearly 70 years, various countries have been trying to find optimal solutions to this problem.

For years, the largest producers of radioactive waste disposed of their problem by dumping it into the sea. Hundreds of thousands of tons of waste from the United States, the UK, Switzerland, and France were sunk in various basins until this practice was banned in 1993.

The Soviet Union also dumped significant amounts of waste, even sinking entire ships filled with waste and reactors containing fuel, such as the K-27 submarine with a complete nuclear power plant.

The scale of this operation was so dangerous that the West, including countries like Germany and Norway, funded the construction of a storage facility for Russia in the Saida Bay (Sajda Guba) near Murmansk. Opened in 2008, this storage was presented by Russian propaganda as a success for the Putin administration.

Russia ended the agreement allowing funding countries to oversee the proper securing of waste in November 2024.

Ultimately, all these actions are merely stopgaps. The safe and long-term storage of waste, which could remain hazardous for thousands of years, is expected to be solved by deep geological repositories. These underground storage facilities are located in appropriately stable geological structures with no risk of underground water circulation. Radioactive waste is sent there for long-term—essentially eternal—storage from our current human perspective.

Currently, several such facilities are operating or under construction worldwide, with the aim of storing radioactive waste at significant depths, usually several hundred meters.

Examples of these repositories include the Swedish Äspö Hard Rock Laboratory, the Belgian HADES Underground Research Facility, and the Finnish Onkalo (Finnish for "hidden place"). The deepest repository, the Mizunami Underground Research Lab, is currently being built by Japan, aiming to store its waste in granite shafts at a depth of 3,281 feet.

The construction and planning of such facilities come with a significant challenge, not just ensuring their immediate security but also marking them in a way that the dangers within are understandable to both contemporary humans and our distant descendants, who may come across them in 1,000 or 10,000 years.

The challenge is even greater given that we do not know what language future explorers will speak or which cultural codes they will understand. If they are not adequately warned, they might breach these sites—much like past explorers who entered ancient ruins without understanding the builders' language or symbols.

This is why Americans planning the security of the Waste Isolation Pilot Plant (WIPP) established a group called the Human Interference Task Force, consisting of engineers, anthropologists, nuclear physicists, and behavioral scientists. Their task was to develop a method for preserving knowledge about hazardous waste for thousands of years.

Among the ideas was creating a "nuclear monastic order," which would preserve fear of the repository through the ages like religious beliefs. Stanisław Lem, who participated in the effort, proposed cultivating plants that, due to genetic modifications, would grow only in contaminated areas.

French philosophers showed creativity by suggesting that cats could act as carriers of warnings. They assumed that cats, which have accompanied humans for thousands of years, would continue to do so. These cats would be genetically modified to change color in response to radiation, and the fear of locations where cats change color would be instilled in the culture through stories or songs.

Ultimately, the task of developing warnings to protect future explorers from accidentally entering the WIPP was entrusted to the Department of Energy, which is working on a marking system called Passive Institutional Controls.

Aside from graphical information, the markings will include above- and underground installations with information, various markers, granite pillars forming the above-ground outline of the repository, and metal elements pointing to the location of underground stores.

Additional information in many languages will be stored in archives around the world—all to minimize the risk that knowledge of the hazardous waste might be forgotten in the future. This multifaceted marking system is expected to be ready by 2033.