Wednesday, June 26, 2019

Inside the World's First Long-Term Storage Facility for Nuclear Waste

Robert narrates below how nuclear spent fuel rods are left to decay naturally inside a storage site in Onkalo, Finland...

The Hiding Place: Inside the World's First Long-Term Storage Facility for Highly Radioactive Nuclear Waste
Robert Macfarlane
Jun 25, 2019

Uranium is mined as ore in a handful of countries—Canada, Russia, Australia, Kazakhstan, and the United States among them. The ore is crushed and milled; the uranium is leached out with acid, converted to a gas, enriched, consolidated, and then processed into pellets. A single pellet of enriched uranium one centimeter in diameter and one centimeter long will typically release the same amount of energy as a ton of coal. Those pellets are sealed within gleaming fuel rods, usually made of zirconium alloy, which are bundled together in their thousands and then placed in the reactor core,
where fission is initiated. Fission produces heat, which is used to raise steam; the steam is ducted to turbines, turning their blades and producing electricity.

Once the fission process has slowed below a horizon of efficiency, the rods must be replaced. But they are still intensely hot and lethally radioactive. The unstable uranium oxide continues to emit alpha and beta particles, and gamma waves. If you were to stand next to an unshielded bundle of fuel rods fresh from the core, radioactivity would plunder your body, smashing cells and corrupting DNA. You would be likely to die within hours, vomiting and hemorrhaging.
 
So spent rods are slid out of the reactor by machine, kept always under water or another shielding liquid as they are moved, then typically stored in deep spent fuel pools for several years before being sent for reprocessing or dry cask storage. Down in the fuel pools the water patiently absorbs the particle hail from the rods. Because this hail heats the water, it must be continuously circulated and cooled in order to prevent it boiling off and leaving the rods disastrously unshielded.

Even after decades in the pools, however, the rods are still hot, toxic, and radioactive. The only way for them to become harmless to the biosphere is through long-term natural decay. For high-level waste this can take thousands of years, during which time spent fuel must be kept secure: segregated from the air, from sun, from water, and from life.

The best solution we have devised for securing such waste is burial. The tombs that we have constructed to receive these remains are known as geological repositories, and they are the Cloaca Maxima— the Great Sewer— of our species. Into low- and intermediate-­level repositories go the lightly radioactive materials that are the byproducts of nuclear power and weaponry: the items that will remain harmful only for scores of years—the clothes, the tools, the filter pads, the zippers, and the buttons. All are barreled up and lowered into holes in silos that have been sunk below ground at
storage sites around the world. Each new layer is packed in concrete, ready for its supercessor. The Waste Isolation Pilot Plant — the intermediate-­level repository dug into the salt beds of New Mexico — is intended to receive 800,000 55-gallon soft-steel drums of military-origin trans-uranium waste, holding among other substances the radioactive shavings from U.S. nuclear warhead manufacture. The WIPP drum chambers will in time form neat strata, standing as highly organized additions to the rock record — another taxon of Anthropocene future fossil.
The most dangerous waste, though — the toxic and radioactive spent fuel rods from reactors — requires even more secure burial: a special funeral and a special tomb. We have only ever attempted to construct a few such high-level waste repositories. Belgium has sunk a test site to research future deep repository possibilities, and has named the facility HADES. America's attempt at a high-level repository took place at an extinct super-volcano called Yucca Mountain in the Nevada desert, but construction was suspended after decades of controversy and protest, and the caverns tunneled into
the ignimbrite currently stand as empty halls. Among the reasons for the suspension of the project is Yucca Mountain's proximity to a 900­-foot­-wide earthquake zone, the Sundance Fault, which is itself undercrossed by a deeper fault called Ghost Dance. If Yucca Mountain were ever to be filled to capacity it would hold, writes John D'Agata, "the radiological equivalent of two million individual nuclear detonations, about seven trillion doses of lethal radiation," enough to kill every human on Earth 350 times over.

By far the most advanced of all these deep storage facilities is Onkalo, set 1,500 feet down into 1.9-billion-year-old rock on the Bothnian coast of Finland. When the burial chambers of Onkalo are full with waste from the three nearby power stations of Olkiluoto, they will hold 6,500 tons of spent uranium. Radiation is a hazard only if incorrectly handled. People think nuclear waste is harmful for eternity. It isn't! After 500 years, you could take spent uranium into your home.

Spent fuel rods are encapsulated inside eight feet long inert copper canister, a foot and a half in diameterhe, for long-term storage. Inside the copper canister is a cast-iron canister, which has been internally partitioned so that it resembles a tic-tac-toe board, with gaps for the squares. Into these gaps will be slid the zirconium alloy fuel rods containing the spent uranium pellets. Each canister will weigh around 25 tons when complete; each canister will be nested in a bed of water-absorbing bentonite clay, inside a cored-out tube of gneiss, 1,500 feet down into the gneiss and granite bedrock.
 
A copper canister and the cast iron canister that fits inside it, into which spent fuel rods from the Olkiluoto nuclear power plant will be placed for long-term storage.
The landscape below which the Hiding Place is sunk has been flattened by the glacial ice that has rolled repeatedly over it in the past two million years. Erratic boulders big as buildings lie among trees where the last ice left them. The glaciers do not feel long gone, as if they will be back soon.

The mouth of the Hiding Place is a ramp blasted down into the gneiss. Lichen has already begun to colonize the exposed rock around the entrance: orange lipstick-kisses of Xanthoria. A shutter-gate locks off the ramp in case of accident. Now the gate is raised—and below it a tunnel angles down into darkness.

Shotcrete walls, unnaturally smooth. Green side-lights diminishing in size. Signs declare the speed limit at the end of the world to be 20 kmh. Utility cables droop between brackets. A gurgle of water runs down a gutter. Air moves coldly up from below, stirring stone dust. The Earth is our tabernacle, a receptacle for all decompositions.... From the threshold the tunnel leads down and around in a steady crooked three-mile spiral before leveling out at the burial chambers themselves.

Seen in abstract, as if the rock that encases it does not exist, the Hiding Place has an elegant simplicity. There are three central shafts dropping vertically downward from the surface: ventilation in, ventilation out, and an elevator.

Around these shafts the transport ramp turns in its helter-skelter, descending at last to a complex excavated space nearly 1,500 feet deep. Outward from the central space extends a network of storage tunnels, into the floor of each line of which are bored the receptacle wells for the fuel rod canisters. When Onkalo is ready to receive its first deposition, there will be more than 200 storage tunnels, which together will hold the 3,250 canisters. In their form these tunnels resemble to me the chambers and galleries that boring beetles make under tree bark, creating space in which to lay their eggs and rear their larvae before they kill the tree that feeds them.

Onkalo, by contrast, is constructed with the desire that its contents never be retrieved. It is a place that confronts us with timescales that scorn our usual measures. Radiological time is not equivalent to eternity, but it does function across temporal spans of such breadth that our conventional modes of imagination and communication collapse in consideration of them. Decades and centuries feel pettily brief, language seems irrelevant compared to the deep time stone-space of Onkalo and what it will hold. The half-life of uranium-235 is 4.46 billion years: such chronology decenters the human, crushing the first person to an irrelevance.

The tunnel curls around and back. The air hums oddly. Unseen machines undertake obscure tasks. At a depth of 1,000 feet we enter a series of big side­ chambers. In the first stands a yellow drilling engine, unmanned but with its eight halogen eyes glaring, its drill arms still drooling water. The keys are still in the ignition. The shotcrete chamber roof is slotted with silver and red bolt-plates. New drill holes in the roof weep onto us. The halogen casts hard shadows.

The bare walls of the chamber are covered in cave art: spray-paint markings in blue, red, apple green, nuclear yellow. The rock is adorned with numbers, pictograms, lines, arrows, and other codes I cannot decipher.

The Greek word for "sign," sema, is also the word for "grave." Around 1990 the research field of nuclear semiotics was born. As plans developed for the burial of radioactive waste, so the question emerged in America of how to warn future generations of the great and durable danger that lay at depth. It became important, the U.S. Department of Energy decided, to devise a "marker system" that could deter intrusion into a repository "during the next 10,000 years." The Environmental Protection Agency founded a "Human Interference Task Force" charged with the imagining of such a system
for the entombment sites under construction at Yucca Mountain and in the New Mexico desert. Two separate panels were convened to consider the issue of the "marker system," reporting to an overall Expert Judgment Panel. Among those invited to express interest in joining the panels were anthropologists, architects, archaeologists, historians, graphic artists, ethicists, librarians, sculptors, and linguists, as well as geologists, astronomers, and biologists.

The challenges faced by the panels were formidable. How to devise a warning system that could survive — both structurally and semantically — even catastrophic phases of planetary future. How to communicate with unknown beings‑to‑be across chasms of time to the effect that they must not intrude into these burial chambers, thus violating the waste's quarantine?

Several proposals developed by the panels involved forms of what is now known as hostile architecture, but which they referred to as "passive institutional controls." They suggested constructing above ground at the burial site a "Landscape of Thorns" (50-foot-­high concrete pillars with jutting spikes that impeded access and suggested "danger to the body"), a "Black Hole" (a mass of black granite or concrete that absorbed solar energy to become impassably hot) and "Forbidding Blocks" (the bulks of which might intimidate a visitor into turning back).

The panel members realized, however, that such aggressive structures might act as enticements rather than cautions, suggesting "Here be treasure" rather than "Here be dragons." Prince Charming hacked his way through the briars and thorns to wake Sleeping Beauty. Howard Carter excavated Tutankhamun's tomb despite the multiple obstructions placed in the way of access, and the warnings given in languages other than his own.

Other proposals from the panels involved versions of a transcendental signifier. Human faces could be carved into stone: pictograms or petroglyphs conveying horror. Munch's The Scream might be taken as a model, it was suggested, on the grounds that it could still somehow communicate terror to whatever being approached it in the distant future. Or a durable aeolian instrument might be constructed that tuned the far-future desert winds to D minor, the chord thought best to convey sadness.

The semiotician and linguist Thomas Sebeok argued on grounds of futility against the search for a transcendental signifier that could outlast all corruption and mutation. Such a sign did not exist, he said. Instead he proposed working toward what he called a long-term "active communication system" that relayed the nature of the site using story, folklore, and myth. Such a means of transmission— perpetuated by an elected "atomic priesthood"— would be flexible, allowing retellings and adaptations to occur across generations. In this way what began as a simple set of warnings might be reconfigured as, say, a long poem or folk epic, made narratively new for each society in need of
warning. Those ordained into the priesthood would have the responsibility of "laying a trail of myths about the [burial sites] in order to keep people away."

The Waste Isolation Pilot Project in New Mexico is currently due to be sealed in 2038. The plans for marking the site remain under development. Among those advising the project are social scientists and writers of science fiction. Plans for what Gregory Benford has called "our society's largest conscious attempt to communicate across the abyss of deep time" include the following measures.

First the chambers and the access shafts will be backfilled. Then a 30-foot-high berm of rock and tamped earth with a core of salt will be constructed, enclosing the above­-ground footprint of the repository. Buried in the berm and the earth around it will be radar reflectors and magnets, discs made of ceramic, clay, glass, and metal, engraved with warnings: Do Not Dig or Drill. The berm itself will be surrounded by an outer perimeter of 25-foot­-high granite pillars, also bearing warning texts.

Set flat near the berm will be a map measuring 2,200 feet by 600 feet. The map will be slightly domed so that it sheds sand in the wind, and does not itself become buried. The continents will have granite edges, the oceans will be represented by caliche stone rubble, and marked on the map will be the world's significant radioactive burial sites. An obelisk will indicate the WIPP site: You Are Here.

Close to the WIPP map what is called a "Hot Cell" will be constructed: a reinforced concrete structure extending some 60 feet above the earth and 30 feet down into it. "Hot" because it will house small samples of the interred waste, in order to demonstrate the radioactivity of what is buried far beneath.

Within the curtilage of the berm an information chamber will be built of granite and reinforced concrete, designed to last a minimum of 10,000 years. The chamber will carry stone slabs into which will be inscribed more maps, timelines, and scientific details of the waste and its risks, written in all current official United Nations languages, and in Navajo.

Buried directly below the information chamber will be a "Storage Room." This room will have four small entrances, each secured by a sliding stone door. In the room will be messages of warning cut into stone and simply phrased:

We are going to tell you what lies underground, why you should not disturb this place, and what may happen if you do.

This site was known as the WIPP (Waste Isolation Pilot Plant Site) when it was closed in 2038 A.D.

The waste was generated during the manufacture of nuclear weapons, also called atomic bombs.

We believe that we have an obligation to protect future generations from the hazards that we have created.

This message is a warning about danger.

We urge you to keep the room intact and buried.

That configuration of berm, map, Hot Cell, information chamber, and buried Storage Room — all set atop the casks of pulsing radioactive molecules entombed deep in the Permian strata — seems our purest Anthropocene architecture yet, and the greatest grave that we have so far sunk into the underland. Those repeated incantations — pitched somewhere between confession and caution—seem to me our most perfected Anthropocene text, our blackest mass.

But I know also that even those words will decay over the course of deep time—blasted from the stone by desert wind, eaten from it by atmospheric moisture, or lost in translation. For language has its half-life too, its decay chain. The written history of humanity is only around 5,000 years old, when cuneiform first emerged. Our language systems are dynamic, our inscription systems vulnerable to destruction or distortion. Most ink is perishable in direct sunlight, fading within months toward invisibility. Even if lettering is inscribed in durable substances, there is no guarantee that it will be legible to future audiences. Today perhaps a thousand people in the world can understand cuneiform.

Those in charge of the burial chambers at Onkalo are largely unconcerned about how to communicate warnings to future generations. They know that, at their latitude, the forest will soon begin to grow over abandoned land, concealing the above­-ground presence of the site. They know too that once the forest has grown it will not be long, in terms of Earth time, until the glaciers return to this region. They know that the passage of the ice will smooth out all signs of what has been done here, placing the whole terrain under erasure.
 
At the lowest point of Onkaloa an arched side tunnel leads off the terminal chamber. The tunnel's floor is flat and screeded. Sunk into that floor are two cored­-out cylindrical spaces. These are burial holes awaiting their bodies.

Each hole is eight feet deep and five feet in circumference, protected by a circular yellow guardrail.

At the tunnel's mouth sit a gray melamine table and a brown plastic chair. Until the lethal canisters arrive this is a workplace, and as in all workplaces there are forms that require filling in and legs that need resting.

A series of brown plastic panels are bolted to the side of the tunnel, and on them an unknown finger has sketched pictures in the stone dust that clings to the plastic. There are three panels. On the left-hand panel the finger has drawn a landscape with a storm, a tree, a house. On the center panel, a rabbit sitting on a cloud. On the right-hand panel is a human face with a crinkled smile.

Once the canisters of waste have been deposited in Onkalo and all the reception cylinders are replete, the spiraling access ramp will be backfilled, the ventilation shafts will be backfilled, the lift shaft will be backfilled, and at last the mouth of the tunnel entrance will be backfilled—two million tons of bedrock and bentonite, sealing those canisters in place, keeping the future safe from the present.

(Excerpted & edited from Underland by Robert Macfarlane.)

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