Gerhard Proehl Overview on projects on disposal of high level radioactive waste in Europe CLasses of radioactive waste in total volumes in storage and disposal, based on the 2016 inventory data (IAEA, 2022). o VLLW and LLW comprise more than 90% of the total volume o ILW and HLW typically comprise more than 95% of the total radioactivity. Aims of Disposal of Radioactive Waste •  To contain the waste •  To isolate the waste from the accessible biosphere •  To reduce likelihood of inadvertent human intrusion into the waste
3

Near surface •  Short-lived radioactive waste •  Low-level waste ( LLW) •  lintermediate level waste (ILW) •  Available in many countries Geological •  For all types of radioactive waste and disused sources •  Especially for high level waste: Spent nuclear fuel and reprocessing waste •  Not yet available in most countries Host rocks for disposal of HLW — Salt l Clay l Crystalline
•  Rock salt behaves plastically under pressure — The formation of cracks and fissures is largely prevented. — If cracks do form, they heal quickly.
• Permeability
— The permeability of rock salt is extremely low. – It can be considered almost impermeable, which ensures the insolation of the waste.
• Thermal conductivity
— Higher specific thermal conductivity than granite or clay. — Heat-generating radioactive waste can be packed more densely than in granite or clay.
• Engineering
Due to its mechanical properties, the construction of large cavities in rock salt is possible
•  Salt is a commodity
– If the knowledge on the disposal facility gets lost, the likely hood for human intrusion increases

• Clay is impermeable to water
– Once the radioactive waste are disposed, they will remain there in the disposal. — The water with the dissolved substances in the rock pores is practically immobile.
• Clay minerals are negatively charged
— High sorption capacity for cations, most radionuclides in the wastes are cations – Cations in contact with clay will be strongly bound — But anionic radionuclides as e.g., l-129, Tc-99, Se-79 are not bound
• Swelling in contact with water
— In contact with water, it swells and — if there are any cracks —  the cracks are sealed.
• Disadvantage
– Clay is demanding from a structural engineering point of view. – The heat conductivity is low.

•  Crystalline is a hard rock
— Usually occurring in massive form — It may be dissected into cuboid blocks by horizontally and vertically running fissures
• Permeability
— The permeability is low for unfractured crystalline — Fissures in fractured crystalline cause high permeability
• Isolation of waste
— Engineered barriers have a key role for ensuring the long-term isolation of the waste from the surrounding environment — The waste will be packed in welded copper canisters
Favorable feature
Medium Examples of disposal facilities planned or under construction
•  Most advanced project for HLW in Europe, under construction since late 2016 •  Located near the Baltic coast in south-west Finland •  Disposal of spent fuel in crystalline rock at a depth of 400 m •  The waste will be enclosed in copper canisters •  In 2021, Posiva, the Finnish waste management organisation, started constructing the first emplacement drift •  To come into operation in the mid- 2020s
•  The underground laboratory in Onkalo: - To study the host rock - To support  the safety assessment •  Disposal of spent fuel •  Built in granite • Consists of an engineered system of tunnels.
Canisters are surrounded by bentonite clay in individual deposit holes at 500 m depth in granitic bedrock
•  An underground laboratory is in operation since the year 2000 by ANDRA (French waste management organisation) – Located about 250 km east of Paris in the municipality Bure •  The potential site for disposal of reprocessing waste is Cigéo, which is nearby • The waste will be disposed in a  clay rock formation at a depth of about 500 m • The construction licence application will be submitted soon • The disposal facility could go into operation around 2040
•  2008: Start of the site selection process •  2022: Selection of a clay formation “Nördlich Lägern" in North Switzerland  near the German border •  2024: Submission of a general license application •  2034: Construction work for underground studies •  2045: Construction of the section for LLW and ILW •  2050: Starting disposal for LLW and ILW •  2055: Construction of the section for HLW •  2060: Starting disposal for HLW •  2085/2090: Closure The Opalinus Clay was formed 175 million years ago. At that time, Northern Switzerland was covered by a shallow sea. Opalinus clay is solidified fine mud that was  deposited on the seabed. •  The name comes  from the extinct  mollusc “Leioceras opalinum” found in it.
•  The Netherlands has only small amounts of HLW to be disposed of. •  An above ground storage facility for HLW was built in the South of Netherlands — The facility is dedicated for long-term interim storage for at least 100 y. – Constructed in compliance with very high safety standards, i.e. it can resist fire, earthquakes, explosions, direct aircraft impact and flooding — It is operated by COVRA (Dutch waste management organisation) – The facility in operation since 2003. •  Finally, the waste will be disposed in a deep geological formation – Site selection process to start by the end of this century?
•  Spent fuel will be disposed in crystalline rock –  Site is close to the Forsmark NPP near the Baltic Sea, 140 km north of Stockholm. •  License application for construction was submitted in 2011 – The government’s assessment is ongoing — Questions regarding the corrosion resistance of the copper disposal canister came up – Additional material was submitted •  Construction of the facility could start in the mid-2020s. •  At the same site, a disposal facility in crystalline rock for LLW and ILW is in operation since 1988.
Concept for disposal of spent fuel •  Spent fuel assemblies to be disposed of in a deep geological disposal •  The site selection process: – Based on voluntary applications from potential siting communities – Ongoing since 2010 • The last two remaining sites are in the Province of Ontario (East Canada). – South Bruce: Sedimentary rock (argillaceous limestone) – Ignace: Crystalline rock (granite) •  In 2021, the South Bruce site will be further explored by drilling deep boreholes. • The siting decision is expected for around 2023.
Areas that could be considered for siting a disposal facility for HLW
Gorleben
•  Gorleben (North Germany) was selected in 1977 for disposal of HLW in rock salt –  Underground Investigations from 1979 - 1999.  (In 1999, the Green Party became part of the federal government for the first time). – Finally excluded as a site in 2020
A new process for site selection
•  The site selection process for a deep geological disposal for spent fuel and reprocessing waste restarted in 2017 — It began with a “white map of Germany”. •  Potential host rocks include granite, salt and clay. •  An interim report was published in 2020 on the 1st phase of site selection — The report lists the regions that have already been excluded from the selection process — It names those regions that will be examined in more detail during the next phases. •  Originally, the most suitable site should be identified by 2031 in a three-stage process. — In the meantime, a delay of 15 years has been announced.

Waste Isolation Pilot Plant (WIPP)
•  WIPP is in operation in Carlsbad, New Mexico, since 1999. •  Dedicated for military transuranic waste built into rock salt at a depth of 655 metres. •  The closure of the WIPP is expected around 2050. The USA has several near-surface disposal facilities for LLW and ILW.
Yucca Mountain
•  Yucca Mountain is a volcanic ridge in Nevada Test Site about 160 km northwest of Las Vegas. •  The host rock is tuff – Yucca Mountain is made of layers of ashes from volcanic eruptions that happened more than 10 million years ago. – The facility would be about 300 m below the top of Yucca Mountain and about 300 m above the aquifer underlying the disposal. •  Natural and engineered barriers would be used to isolate the waste from the surrounding environment. — If constructed, it would use a tunnel complex in the mountain. •  Dedicated for disposal of 70000 tons of spent fuel (SNF) and reprocessing waste •  Application for licensing in 2008, no decision so far. A long way from the concept to start of disposal

The near field
— Types of waste •  Origin, nature, quantities and properties of waste • Radionuclide inventory – System engineering •  Waste conditioning and packaging, disposal units • Engineered barriers, cover of the disposal facility, drainage features — Extent and properties of the zone disturbed by any excavation or construction work
The far field (from waste to biosphere)
– Geology, hydrogeology, hydrology, geochemistry — tectonic and seismic conditions, erosion rates
The biosphere
— Location of the disposal facility –  Climate and atmosphere, water bodies — Biota, soils, topography and the geographical extent and — The local population, human habits

The biosphere
— Location of the disposal facility –  Climate and atmosphere, water bodies — Biota, soils, topography and the geographical extent and — The local population and human activities
The far field (from the waste to the
biosphere)
– Geology, hydrogeology, hydrology, geochemistry — Tectonic and seismic conditions, erosion rates
The near field
– Types of waste •  Origin, nature, quantities and properties of waste • Radionuclide inventory – System engineering •  Waste conditioning and packaging, disposal units • Engineered barriers, cover of the disposal facility, drainage features – Extent and properties of the zone disturbed by any excavation or construction work
•  Site characterization is time-consuming – Development of geosphere, hydrosphere, lithosphere, biosphere, climate ... — Engineering has to be adapted to results of site conditions •  A comprehensive assessment is required including all aspects – Demonstrate compliance with safety requirements and standards – Demonstrate compliance with radiological criteria – Need to cover time frames of up to 1 million years •  Radioactive waste disposal projects are very unpopular — Lack of public acceptance in many countries – A lot of objections and court cases – Reluctance of politicians to move these projects forward: Commitment to a repository is not good for the next elections •  Time-consuming evaluation of the license application – Complex system with many interaction between biosphere, geosphere, hydrosphere – Availability of experts for evaluation who are not directly or indirectly involved in disposal projects Not with us" Thank you!