UNESCO

Half a Meter to a Meter: The Deep-Time Reality of Nuclear Waste

2025-08-21

Why high-level waste still needs shields — and memory beyond a million years

When it comes to high-level waste repositories, the old reassurance—“radioactivity falls back close to or below natural levels”—is misleading. Yes, if you total up all the radioactivity in a repository and compare it to the original ore, the sum may look modest after ten to a hundred thousand years, depending on waste type. But people (and animals) don’t meet sums. They meet things: individual containers, cores, and fragments that concentrate radioactivity. What matters—ethically and practically—is the radiation dose at the surface of each piece as time rolls on.

*Example of plot of total radioactivity versus original uranium ore. (Report SKB-TR-97-13)*

A new new paper looks squarely at that reality. Rather than only computing dose, a concept for radiation specialists, it asks a tangible question: how thick must a shield be to meet modern protection limits—not just now, but at one million years and beyond? Using concrete as the reference, the answer comes in units anybody can picture: roughly 50 to 90 centimeters at a million years, depending on the waste and the protection target.

Namely, at one million years,
Spent fuel about 67 to 93 centimeters of concrete is needed for a representative multi-ton package (ignoring any cask shielding)
Vitrified waste about 53 to 72 centimeters is needed for a full-size cylinder.
Beyond a million years, since uranium-238 lasts for billions of years, it sets the shielding needs to a practically constant non-zero value. In the absence of containers, concrete thickness requirements range between 17 and 42 cm for vitrified waste cylinders, and 62 to 87 cm for spent fuel.
Smaller isn’t safer. Even drill cores (say, 40 cm tall by 10 cm wide) or fragments still need shielding on the same order, because near-surface dose depends on what’s inside, not the item’s size. At a million years, unshielded drill cores from these mainstream inventory still translate into ~48–67 cm of required concrete for vitrified waste; 46-72 cm for spent fuel drill cores.
Scale matters. Numbers per item are only half the story. Program scale multiplies these requirements: for example, Sweden plans roughly 6,000 spent‑fuel canisters. In France, there will be >50,000 vitrified waste cylinders.

Concrete shielding thickness at ~1 million years for spent fuel (full canister and drill core) and vitrified high-level waste (full cylinder and drill core). Results are shown for two current protection targets: 0.02 mSv/h (brief, one hour of exposure) and 0.002 mSv/h (background). Figures are illustrative; actual design requirements are project-specific.

What this means in human terms

Heritage, not waste alone. If descendants encounter these materials—by curiosity, drilling, erosion, or chance—they won’t face a vanishing hazard but an enduring one, beyond legal timeframes and planning horizons. Our commitment to protect future people “to levels comparable to today” becomes concrete—literally—in centimeters of real shielding.
Justice and foresight. Thinking “per item” reframes responsibility. Are we designing containers—and contingencies—that keep each piece safe, including broken pieces? Are we documenting the long-lived contents that set deep-time dose? We should.
Design humility. Landscapes move; encounters may occur. The ethical stance is not to promise a perfect fortress forever, but to equip future people with buffers that still work: robust, intelligible, maintainable shields—and the memory provisions (markers, archives, institutional handovers) to keep that knowledge alive. Also, acknowledge that danger never really fades away.

So what now?

Build for fragments. Don’t just model intact packages; assume cores, partial breaches, and erosion-revealed segments—and assign them shielding, too.
Specify the long-lived drivers. Make a standard reporting of the deep-time isotopic loadings, because they determine the shield.
Design the message with the material. If safety demands 50–90 cm at a million years, our markings and archives should be designed to last—and be rediscoverable—on comparable horizons. Or that should be the ambition.
Expand the lens. Apply similar analyses to long-lived “medium-level” wastes that carry significant long-term gamma issues.

Takeaway: this isn’t a new fear; it’s a clearer ethic. We owe the future not only sealed vaults and clever signs, but credible buffers—thicknesses you can measure with a ruler—matched to how matter behaves over time. The shield is not a metaphor; it’s a promise we can make, and keep.

Archaeology of Garbage

2025-08-01

A new interview published in Brazil featuring the Chair’s affiliated researcher Dr Leila Papoli-Yazdi tells the significance of the archaeology of garbage, not the least for the future:

By connecting her research to the idea that archaeology can “build futures”, Leila reveals the potential of garbology as an interdisciplinary and transformative practice that illuminates not only the past but also the challenges of the present and the possibilities for a more just and sustainable future.

Full reference:

Papoli-Yazdi, Leila, Tiago Silva Alves Muniz, Camilla Agostini (2025) Archaeology of garbage: from disaster archaeology to social entrepreneurship. Vestígios – Revista Latino-Americana De Arqueologia Histórica, 19(2), 317-326. https://doi.org/10.31239/j677sr71

This interview explores Professor Leila’s pioneering work in the archaeology of garbage, tracing her journey from disaster archaeology in Iran to the establishment of Europe’s first start-up focused on garbology. Initially working in Tehran, Leila faced challenges linked to Iran’s political climate and the adaptation of traditional garbological methods to urban environments. Upon moving to Scandinavia, she encountered new professional and cultural dynamics, eventually co-founding Garbonomix – a company dedicated to analyzing consumption habits to support economic resilience. She discusses the interdisciplinary potential of garbology to improve both individual and community well-being, linking academic insights with practical applications. Furthermore, Leila reflects on the stigmatization of contemporary material studies in archaeology, noting the field’s often nationalistic orientation that overlooks recent histories. Her work advocates for a more inclusive, human-centered archaeology that addresses modern issues like poverty and environmental sustainability. Through her engagement with both academic and consulting roles, Leila demonstrates how archaeology can extend beyond traditional frameworks, encouraging practitioners to collaborate with marginalized communities and contribute to social resilience.

Various activities April – June 2025

2025-07-01

Cornelius Holtorf attended the Webinar “Archaeological Cultural Heritage in the UNESCO Mandate” organized by the Polish National Commission for UNESCO, the UNESCO-UNITWIN Network on Culture in Emergencies and the University of Poznan (4 April 2025).

Cornelius Holtorf contributed to the consultation of the Swedish Commission for UNESCO concerning Sweden’s future collaboration with UNESCO (24 April 2025).

Cornelius Holtorf, gave an invited talk on “The Climate Heritage Paradox” for ca 90 participants in the national conference Heritage Horizons: Pathways to the Future by the Heritage Council of Ireland, held in Dublin, Ireland (1 May 2025).

Anders Högberg presented the research programme InKuiS – Innovative Cultural Entrepreneurship in Collaborative Co-creative Research, including the future-related project Earth Logic Design, at a conference organised by the Småland in Academy organised at Linnaeus University in Växjö (16 May 2025).

Cornelius Holtorf participated in a webinar of the “The Path to MONDIACULT 2025” series which is part of the preparations for MONDIACULT 2025, the UNESCO World Conference on Cultural Policies and Sustainable Development (19 May 2025). The 2025 edition of MONDIACULT in Barcelona will be pivotal in ensuring that culture is recognized as a standalone goal in the future United Nations development strategy.

Cornelius Holtorf contributed to a Consultation of the Heritage Adapts to Climate Alliance (HACA) on the UNFCCC process to develop indicators for measuring progress in adapting heritage sites and cultural practices to climate change (30 May 2025).

Cornelius Holtorf attended digitally a High level panel on future generations entitled “A Tribunal for Future Generations” held at the Hamburg Sustainability Conference 2025 and involving, among others, Guy Ryder (Under-Secretary-General, UN Executive Office) and Sophie Howe (The World’s first Future Generations Commissioner, for Wales) (2 June 2025).

Cornelius Holtorf and Anders Högberg held an informal meeting on heritage processes and futures literacy with Dr Anselm Tiggemann of the BGE Bundesgesellschaft für Endlagerung in Berlin to discuss future collaborations (9 June 2025).

Cornelius Holtorf attended digitally parts of The International Seminar on Heritage Interpretation and Presentation for Future Generations co-organized by the Institute of International Studies at Waseda University, Tokyo, Japan; the ICOMOS International Scientific Committee on Interpretation and Presentation of Cultural Heritage Sites, and the Our World Heritage initiative (14 June 2025).

Cornelius Holtorf ran a Future Workshop on “World heritage Southern Öland 25 years in the future” for 20+ students taking part in a course entitled “The World Heritage site of Southern Öland” at Ölands Folkhögskola, Skogsby, Öland, Sweden (18 June 2025).

Cornelius Holtorf arranged and participated in an exploratory meeting for future collaboration with Professor Tatsuyoshi Saijo, Kyoto University of Advanced Science (who has been developing Future Design) and Christine Kavazanjian, UNESCO Paris (representing UNESCO’s unit on Foresight and Futures Literacy), (19 June 2025).

Cornelius Holtorf took part in a meeting of the External Advisory Committee of the Flagship Initiative Transforming Cultural Heritage at the University of Heidelberg, Germany (20 June 2025).

Om framtidsskapande

2025-06-18

Artikel i tidskriften Byggnadskultur (som är svenska byggnadsvårdsföreningens tidskrift). In Swedish.

Anders Högberg, Professor of Archaeology UNESCO Chair on Heritage Futures

Rethinking Futures

2025-05-22

In May, Anders Högberg was invited as keynote speaker at the National Library of Sweden. The invitation came from their Department for Research and Collection Management, which hosted a joint staff day. Högberg presented his research on heritage processes as futures-making practices. In his presentation Anders emphasised that we need new knowledge in order to rethink futures in novel ways. The discussion that followed on the presentation, largely focused on how we can create change to achieve this, what opportunities it might bring, but also which challenges we need to address in order to succeed.

National Library of Sweden. Photo Maria Aho

Relativism and communication with aliens

2025-05-15

Dr Michael Ranta gave a lecture for us today, entitled “On Communication with Remote Cultures and Questions of Relativism” (15 May 2025).

On the picture from the left: Cornelius Holtorf, Gustav Wollentz, Michael Ranta, Peter Skoglund.

Ranta raised some very fundamental issues on truth, representation, communication and aliens:
How would it be possible to communicate with (remote) future generations, which may have different or altered forms of communication, compared to current ones? Apart from language or other communication alterations over time, new semiotic resources (e.g. resulting from technological or medical innovations) may emerge. Moreover, and most probable, the accumulation and processing of knowledge as well as the emergence of altered world views and category systems, or of paradigm changes (in Thomas Kuhn’s sense), may obstruct the comprehension, transmission, and exchange of information. Future generations may thus be confronted with significant obstacles trying to understand or reconstruct our communicative habits. These topics, especially with regard to communication with pictures, will be further elaborated and discussed in this presentation.

Gamma Fields: The Industrial Legacy We Cannot Afford to Forget

2025-04-28

By Claudio Pescatore

What if the true monuments of the nuclear age are not vaults, vitrified blocks, or warning markers—but fields of invisible light?

Gamma radiation is insidious. It leaves no ruin, no ash, no wound you can see. You don’t need to touch it. You don’t need to breathe it in. You simply pass by—and it passes into you. No trace is left on the soil. But a trace is left in you. And when the next person passes, they too receive the signal. Yet the source remains—unchanged, unweakened.
Most poisons are spent as they harm. Gamma radiation is not. It accumulates elsewhere, silently, without diminishing its source. A kind of ambient inheritance.

In a recent study, I calculated the gamma radiation field unleashed by humanity’s Uranium-238 (U-238) legacy. The results show that this field is not temporary. It is already present, slow to mature, but geologically assured and radiologically significant, beyond safety thresholds.

Mill tailings scattered across continents emit gamma radiation through uranium’s progeny. This signal will slowly fade over the next half a million years—but it will reach a baseline, unsafe value and will continue indefinitely.
Meanwhile, depleted uranium stockpiles—which emit almost no gamma today—are quietly maturing. From a few thousand years onward, their gamma output will rise steadily, eventually overtaking significantly that of tailings, peaking in two million years, and continuing unabated into geological time.
Most U-238 residues lie close to the surface—mill tailings, depleted uranium (DU) stockpiles, weapons testing sites, contaminated soils from mining and from exploded DU munitions. Even when their radiation does not cause immediate harm, it defines a long-term environmental signal whose meaning we have barely begun to grasp.

This raises questions not only of science, but of ethics, inheritance, and imagination:

What does it mean to leave behind a hazard that grows in potency over time?
How do we warn future beings of a danger concealed in ordinary soil or dust?
Should gamma radiation be seen not only as threat, but also as a marker of human agency?

Nuclear waste lasts a long time. But U-238 isn’t just persistent—it performs. It changes. It regenerates. It returns. And surprisingly, we don’t call it waste. We call it an industrial by-product.

And now we are not just leaving behind a signal—we are leaving a body.

About 4.5 million tonnes of U-238, mostly in oxide form, now reside in uranium tailings, DU, and spent fuel. It is a real, physical legacy—not symbolic, not speculative. This body must be put away—not forgotten, but deliberately placed and traced. Shielded, marked, and remembered.
We can still act. We can treat uranium’s gamma legacy not as an afterthought, but as a defining part of our industrial inheritance. This won’t undo the past—but it may shape how future generations understand what we’ve left them.

We often speak of the nuclear age as bracketed—confined by Cold War dates or the operational lifespan of reactors. But its material consequences are just beginning. Care begins by acknowledging and tending to what endures.

*Claudio Pescatore is a member of the UNESCO Chair on Heritage Futures at Linnaeus University*

Miras Gelecekleri

2025-04-14

Miras Gelecekleri is “Heritage Futures” in Turkish!

I was interviewed by Erman Ertuğrul for the popular Turkish website arkeofili.

In the interview I am talking, among others, on how I got into archaeology at age 10 and then, much later, into future archaeology.

See for the English version: https://arkeofili.com/on-future-archaeology-an-interview-with-cornelius-holtorf/ and for the Turkish version: https://arkeofili.com/gelecek-arkeolojisi-uzerine-cornelius-holtorf-roportaji/

Thank you, Erman!

New article on urban transformation, heritage and social sustainability

2025-04-03

Bebyggelsehistorisk Tidskrift (Nordic Journal of Settlement History and Built Heritage): Urban transformation, heritage processes and social sustainable futures by Ulrika Söderström & Anders Högberg.

Short summary:

In this study, we use three case studies to discuss heritage processes as future-building practices. Through examples from urban regeneration processes in three Swedish cities, we discuss how these processes have contributed to social sustainability. The case studies are the Caroli neighbourhood in Malmö (transformed 1967-1973), the Valnötsträdet neighbourhood in Kalmar (transformed 2008-2018) and the ongoing transformation of Kiruna city. Our findings show that the cultural heritage processes activated in urban regeneration processes do not always promote socially sustainable future-making practices. We conclude that an engagement in different forms of future-making is crucial for heritage processes to contribute to long-term sustainable urban development. We suggest that this requires a way of thinking and acting that includes change and transformation. Our findings are conceptualised in a model that we hope can be used to understand heritage processes as future-making practices in urban transformation projects.

Bebyggelsehistorisk Tidskrift is a Nordic forum for research and debate on the history of the built environment. It is the Nordic region’s leading academic journal on the history of the built environment. The periodical presents the latest research on the history of the built environment, and also provides a forum for discussing the discipline in practice when buildings and heritage environments are being conserved.

https://bebyggelsehistoria.org/en/bebyggelsehistorisk-tidskrift-english/

Open access (Doctoral Thesis by Ulrika Söderström) https://lnu.diva-portal.org/smash/record.jsf?pid=diva2:1901953

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POSTSCRIPT 13 April 2025. Here is a graphical summary of the paper prepared by ChatGPT:

Various activities January – March 2025

2025-04-02

Cornelius Holtorf took part in the first meeting of the Heritage and Climate Change Working Group of the ICOMOS International Scientific Committee on Interpretation and Presentation (ICIP) (14 January 2025).

Cornelius Holtorf lectured on “Communicating Cultural Heritage with the Future” for 15 students reading the course “Cultural Heritage and Communication” as part of the Undergraduate Programme in Cultural Heritage in Present and Future Socities at Linnaeus University, Kalmar, Sweden (5 February 2025).

Cornelius Holtorf lectured on “Unesco världsarv: vad kommuniceras för framtida generationers skull?” for 15 students reading the course “Cultural Heritage and Communication” as part of the Undergraduate Programme in Cultural Heritage in Present and Future Socities at Linnaeus University, Kalmar, Sweden (10 February 2025).

Cornelius Holtorf participated in a short survey on the illicit trafficking of cultural property, with a particular focus on its online dimension, shaping discussions at the upcoming UNESCO Conference “Addressing Illicit Trafficking of Cultural Property in the Digital Era” to be held at UNESCO Headquarters in Paris on 26 June 2025 (15 February 2025).

Cornelius Holtorf had an informal meeting with Ulrik Brandén, Deputy Mayor of Mörbylånga, Emma Rydnér, World Heritage Coordinator at Mörbylånga Municipality, and Örjan Molander, Director at Kalmar County Museum, on various ideas for collaboration regarding development of the UNESCO World Heritage property Agricultural Landscape of Southern Öland (20 February 2025).

Cornelius Holtorf took place in the regular meeting of the International Scientific Committee on AeroSpace Heritage of the International Council of Monuments and Sites (ICOMOS) which discussed, among others, the recent listing of the sites on the Moon on the World Monuments Watch List 2025 by the World Monuments Fund (21 February 2025).

Cornelius Holtorf attended the 8th Annual Heritage Lecture of the Cambridge Heritage Research Centre on ”Changing concepts Future of the and the ’Ethics of Repair’”, given by Aleida Assmann, Professor of English Literature and General Literary Studies, Universität Konstanz (28 February 2025).

Cornelius Holtorf presented a keynote lecture on “Time Travel – More than Learning About the Past” for ca 50 listeners in the room and another 20 online, coming together for the conference Re-Action: Time Travels in a Changing Worl – Bridging Ages 20 Years in Kalmar, Sweden (4 March 2025).

Cornelius Holtorf had an informal meeting with Steven Hartman, Executive Director of the BRIDGES Sustainability Science Coalition in UNESCO’s Management of Social Transformations Programme (MOST), on ways of future collaboration (7 March 2025).

Cornelius Holtorf met with Shanti Morell-Hart of the Dept of Anthropology at Brown University in Providence, USA, for an informal conversation about seeds and heritage futures (14 March 2025).

Cornelius Holtorf met in Providence, USA, with Philip Segadika of the National Museum of Botswana in Gaborone, Botswana, for an informal conversation about collabloration on heritage futures (16 March 2025).

Cornelius Holtorf participated actively discussing heritage processes and futures literacy in the first Plenary Meeting of the Expert Group on Archiving and Awareness Preservation (EGAAP-1) of the Nuclear Energy Agency held online and at the OECD in Paris (19-20 March 2025).