Cigéo memory: How to warn future generations?

Beyond the technical and operational aspects of the Cigéo geological waste storage solution for radioactive waste, the issue of transmission to future generations arises. How to inform, in thousands of years, about the existence of these sensitive wastes under our (their) feet? The French National Agency for Radioactive Waste Management (Andra) is conducting multiple studies and research on the “Memory for Future Generations” program to cultivate collective consciousness and think about solutions for transmitting this knowledge in the future.

For over 30 years, Andra has been tasked with researching the storage of, among other things, high-level radioactive waste (HLW) and medium-activity long-lived waste (ILW-LL). These wastes can have an extremely long lifespan, in some cases several hundred thousand years. Thus, the Cigéo geological storage solution, located 500 meters underground in Meuse/Haute-Marne, has been selected to contain these wastes and their radioactivity, ensuring they do not pose a future health or environmental hazard, even in the event of a civilization collapse.

HL waste primarily comes from the treatment of used fuels. ILW-LL waste includes the metallic structures that contain the fuel or residues from the operation of nuclear facilities. It is estimated that each French resident generates 200 grams of long-lived radioactive waste per year.

What are the dangers?

These wastes are uniquely hazardous due to their radioactivity. Direct exposure to ionizing radiation (referred to as irradiation) or ingestion of radioactive substances poses a major risk to health and the environment. Practically speaking, prolonged contact (a few seconds) without protection with HA waste can lead to a lethal dose.

Packaging waste parcels, the Cigéo site, and the impermeable Callovo-Oxfordian clay layer will prevent this risk of exposure to the public and personnel managing these wastes. They ensure that during the natural movement of radioactive elements (radionuclides) to the surface over very long periods, their levels reach values comparable to natural radioactivity. The danger of radioactive waste decreases over time due to the natural decay of radioactivity.

Memory: What are the options?

Cigéo was designed to be reversible for at least 100 years to allow future generations to retrieve the waste if, for example, a better solution is found by then. This is known as reversibility. After this period, the site will be sealed, and it is necessary to prevent these wastes from being forgotten, hence the principle of memory. The site must be monitored for at least 300 years, ensuring the memory of its existence. Beyond 500 years, the French Nuclear Safety Authority (ASN) has authorized, from a safety standpoint, the possibility of forgetting.

For ethical and intergenerational reasons, Andra wishes to consider ways to transmit the knowledge and awareness of a storage center like Cigéo from generation to generation on even longer timescales. However, it is impossible to assert with certainty that the site will not be forgotten for such durations. The OECD study “Loss of Information, Records, Knowledge, and Memory” showed that it is almost impossible to forget a storage site on a societal scale. However, details of the site may gradually be forgotten due to loss of archives or environmental factors.

Andra’s memory study takes the form of a program named “Memory for Future Generations.” It is divided into four pillars: regulatory documentation and archives, societal interactions, studies and research, and international collaboration. It aims to consider the best ways to transmit knowledge and to attempt to answer questions posed by such immense time spans: what civilizations, languages, and supports?

Source : ANDRA : Andra’s Memory programme

• The Regulatory and Archives Axis

Andra’s archivists first make a colossal effort to preserve and enhance archive documents. For this purpose, two files are created: the synthetic memory file and the detailed memory file. The former, intended for the general public, contains the main information about the history of the center, its waste, and its risks. The latter, primarily for successive operators of the storage center, is more comprehensive and contributes to a finer understanding of the issues related to the site.

• The Societal Interactions Axis

This axis contributes most to maintaining the existence of storage in collective consciousness over the longest term, using elements of society. This is first translated into organizing social interactions on the site to transmit information directly (consultations, open days, etc.).

Memory groups allow for imagining, experimenting with, and implementing solutions: collection of press articles, conservation of objects related to the center, installation of artworks, playful devices. For example, a comic book titled “Forgotten Memory” was created.

More creative research is conducted to convey knowledge through art. Artists like Cécile Massart or Juliette Nier propose artistic works that transcend the laws of time.

The Andra series “Tomorrow in 1000 Years,” in partnership with Le Drenche, also explores the issue of memory.

• The Studies and Research Axis

The aim is to reflect on messages, supports, and modalities for transmitting memory. An initial step is to understand how previous generations have transmitted their knowledge and heritage.

Research is also conducted on different materials that could endure over time. A geopolymer (a type of ceramic) and “permanent paper” are already used for some objects and archives.

A sapphire disk is also a very good candidate for thisobjective: it can contain the equivalent of 10,000 sheets of A4 paper, completely transparent and colorless, and resistant to temperatures above 1600°C and immune to chemical attacks and scratches.

Paths also turn to landscape archaeology in the form of surface structures, for example, ensuring that traces of deep geological storage cannot be confused with natural phenomena. The sound signage is also explored via the permanence of languages and symbolism. Researcher Paul Bloyer studies the potential of sonic semiotics.

Finally, Andra also tests digital alternatives. In conjunction with the company Eupalia, the Micr’Olonys system would encode a database in a form similar to QR codes.

• The International Collaboration Axis

Andra also works to find solutions within an internationally shared dynamic. The IDKM (information, data and knowledge management) project, which Andra participates in, is an international research and work platform on knowledge and memory in the context of radioactive waste management. It was created by the OECD’s Nuclear Energy Agency (NEA).