National Laboratories Partner on 3D-Printed Nuclear Pressure Vessels

Drilling Operations Underway

Posiva has begun drilling the first deposition hole at the Onkalo repository in the Olkiluoto bedrock, more than 400 meters below the surface. The operation commenced after a safety and technical review meeting. The Deposition Hole Boring Machine (DHBM), manufactured by Herrenknecht AG, was delivered to the Onkalo site in June 2022. This machine, weighing 78 tonnes, is over 9 meters long, 3 meters wide, and nearly 4 meters tall. The drilling complex also includes a 7-meter, 22-tonne energy unit and an 18.5-tonne drill processing plant.

Prior to this, Herrenknecht AG's crew conducted test drilling of four holes in late 2022, followed by Posiva's crew drilling an additional four test holes with supplier assistance. The current deposition hole is being drilled vertically into the floor of an excavated final disposal tunnel. Upon completion, it will be 8.4 meters deep and 1.75 meters in diameter. A strict tolerance of 25 millimeters deviation from the vertical centerline is enforced along the entire length of the hole. The first three holes will undergo additional measurements upon completion to ensure compliance. If the deviation exceeds the permitted limit, the hole will be rejected for final disposal.

Repository Development and Future Plans

Kimmo Lehtola, Posiva's Construction Manager for Operations, stated that drilling an 8-meter hole at Onkalo typically takes about ten hours of effective drilling time. The objective is to achieve a production rate of approximately two finished deposition holes per working week once the process is fully integrated into normal operations. The first final disposal tunnel, approximately 330 meters long, is designed to accommodate around 30 drilled deposition holes.

The Onkalo repository, located near the Olkiluoto nuclear power plant, was selected in 2000. Posiva, jointly owned by Fortum and Teollisuuden Voima Oyj (TVO), submitted its construction license application in December 2013, which was granted in November 2015. Construction began a year later. In July 2022, Posiva announced the completion of excavation for the first five disposal tunnels, totaling about 1700 meters. Over the 100-year operational period, an estimated 100 deposition tunnels, with a total length of approximately 35 kilometers, will be excavated. Posiva submitted its operating license application for the encapsulation plant and final disposal facility in December 2021, seeking approval for operations from March 2024 to the end of 2070. The Radiation and Nuclear Safety Authority (STUK) has indicated that safety requirements for the operating license have been met, with a government decision anticipated in the autumn. Posiva's President and CEO, Ilkka Poikolainen, aims for operational readiness by the end of 2026.

ATLAS Initiative Focuses on Maritime Nuclear Potential

The Atomic Technologies Licensed for Applications at Sea (ATLAS) initiative held its inaugural meeting in the USA, gathering international stakeholders to discuss the future of nuclear energy in maritime applications. A joint statement issued during the event highlighted the potential of advanced small modular reactors (SMRs) as a safe and viable option for the maritime sector. This technology could enable higher-speed commercial shipping with reduced refueling needs and provide versatile energy sources, such as floating nuclear power plants, to supply electricity to coastal or remote communities and industries.

The International Atomic Energy Agency (IAEA) describes ATLAS as the first globally coordinated effort to bridge the nuclear and maritime sectors. The initiative aims to foster collaboration among international nuclear and maritime communities to ensure the safe and secure deployment of these technologies and to enhance safeguards for civil nuclear applications at sea. Advances in reactor design, fuel technology, and maritime engineering suggest that some nuclear maritime designs could be ready for deployment as early as the 2030s.

Broad International Support and Future Workstreams

Initial signatories to the joint statement include Argentina, Bangladesh, Belgium, Brazil, Canada, Denmark, the Dominican Republic, Finland, France, Greece, India, Italy, Japan, Malta, the Netherlands, Norway, Poland, Romania, Saudi Arabia, Singapore, Slovenia, South Korea, Turkey, the UAE, the UK, and the USA. The ATLAS initiative will maintain a technology-neutral approach, acknowledging that designs, business models, and operational concepts for these systems are still in early stages of development.

Following the launch event, six project groups are being established to commence practical work this year. These groups will focus on addressing safety, security, safeguards, and regulatory aspects, while also considering deployment scenarios and other attributes of nuclear-powered shipping and floating nuclear power plants. The IAEA emphasized its role in bringing together regulators, governments, industry, and technology developers to establish the necessary institutional and regulatory frameworks for safe, secure, and safeguarded nuclear technology at sea.

Diverse Applications for Nuclear Maritime Technology

Nuclear maritime technologies are envisioned for a wide range of applications. These include powering large vessels such as container ships, bulk carriers, tankers, cruise ships, icebreakers, and offshore support vessels. Additionally, they could provide reliable electricity, heat, desalination, and emergency power for remote communities, ports, disaster response efforts, and offshore industries. The initiative seeks to transform the promise of offshore nuclear energy and nuclear-powered shipping into commercial reality by addressing practical deployment barriers through collaborative efforts among governments, regulators, and industry.