Frequently asked questions (FAQ) about the BALDER project
Here you will find answers to the most important and most frequently asked questions about our project.
No, the construction of a new nuclear power plant in Switzerland is prohibited under the Nuclear Energy Act (NEA) Art. 12a.
Together with its cooperation partner, the Danish company Copenhagen Atomics, PSI is planning the construction of a nuclear test facility. The aim is to test the reactor concept developed by Copenhagen Atomics and to answer scientific questions on safety and sustainability aspects.
A nuclear experiment will be delivered to PSI for this purpose. Once the tests have been completed, the experiment will be returned to Copenhagen Atomics and will leave Switzerland again.
In the coming years, the two cooperation partners want to jointly research the latest generation of molten salt reactors.
This type of nuclear reactor uses molten salt with uranium fluoride as fuel.
The aim of the experiment at PSI is to validate the technology; it should provide valuable experience for the planning, construction, approval, operation and decommissioning of the new technology and also answer a number of research questions on reactor physics, thermohydraulics and material behavior.
The project name BALDER was taken from the Prose Edda. Balder is a son of Odin and Frigg and is regarded as the Germanic god of the sun. Balder is considered the most peaceful and purest of the Asian gods. All of creation admires his radiant beauty as well as his mercy and wisdom.
The project name BALDER is used as an acronym for the German expression "Bereitstellung der Auslegungs- und Lizensierungs-Dokumente für das Erste MS-Reaktor-Experiment". In English this stands for ‘Provision of design and licensing documents for the first MS reactor experiment’.
The experiment is a 1:1 demonstration plant of Copenhagen Atomics' reactor design, but with a hundred times less power and a maximum operating time of 30 days.
The reactor technology developed by Copenhagen Atomics is not only the molten salt reactor itself, but also a modular technology that makes it possible to build and transport the reactor in a shipping container. This makes the technology mobile and no longer permanently installed in one place.
Copenhagen Atomics and PSI are planning to build a nuclear test facility for the phased testing in which the experiment is be installedto; the entire facility is to demonstrate in the experiment that it meets the criteria of a nuclear facility with low hazard potential. Once the tests have been completed, the entire experiment is to be transported back.
The long-term goal is to develop a process that generates energy while using the fuel sustainably.
In the planned experiment at PSI, for example, researchers are investigating whether the materials used behave as predicted. Changes can be identified and the materials optimized accordingly. The behavior of the reactor and the fuel itself is also of interest, such as which fission products are formed and in what quantities.
For this purpose, the molten salt reactor is operated at one hundredth of the nominal output. Even at this low power, important scientific conclusions can already be drawn about the behavior of the plant under operational and accident conditions, which are essential for the safety case.
According to the Nuclear Energy Ordinance (NEO) Art. 22 para. 1, nuclear installations with a low hazard potential are nuclear installations "where the frequency of all incidents [...] with a resulting dose of more than 1 millisievert (mSv) for members of the public is no more than 10-6 per year".
By way of comparison, the average natural radiation exposure per person for the Swiss population is around 5 mSv per year. A return overseas flight exposes a person to an additional radiation dose of around 0.1 mSv.
The frequency of 10-6 per year means that, in purely statistical terms, a maximum of one incident occurs in a million years. During normal operation, i.e. the experiment, there will be no increased radiation exposure for the environment or the population.
As the experiments planned by Copenhagen Atomics are of a low hazard potential, the newly planned nuclear test facility does not require a general license from the Federal Council in accordance with Art. 12 para. 3 of the Nuclear Energy Act (NEA).
A construction and operating license are sufficient.
The construction permit for the plant is the responsibility of the Federal Department of the Environment, Transport, Energy and Communications DETEC (Art. 15 NEA). The Swiss Federal Nuclear Safety Inspectorate ENSI is responsible for the safety-related review of the submitted documents. ENSI is also responsible for nuclear supervision of the PSI nuclear facilities.
Naturally.
A license is only granted if it can be proven that the planned experiment in the nuclear test facility is safe and that the entire facility corresponds to a facility with a low hazard potential.
Otherwise, the licensing authority will not issue a license.
The Swiss Federal Nuclear Safety Inspectorate ENSI defines the licensing process taking into account its experience with new technologies such as molten salt reactors in comparison with conventional nuclear reactors.
If necessary, external experts are consulted and commissioned, or there is an exchange with international authorities and experts.
As the technology differs from conventionally operated reactors, some of the known risks are already eliminated by the design. To this end, new potential risks are defined and safety measures are taken. These are described in detail in the safety report, which PSI is preparing with the support of Copenhagen Atomics.
The Nuclear Energy Act (NEA) and the Nuclear Energy Ordinance (NEO) as well as other laws and ordinances define the licensing process for all nuclear installations.
ENSI guidelines already exist for nuclear installations other than nuclear power plants. ENSI also has the option of applying international standards and guidelines.
It is up to the legislator to decide whether such a specific directive is useful or necessary.
According to Art. 12 Para. 3 of the Nuclear Energy Act (NEA), a general license from the Federal Council is not required for plants with a low hazard potential.
As a rule, this also means that no formal public participation is required, as is the case for larger or higher-risk projects.
However, there are extensive opportunities for objections before a permit is granted. In Switzerland, several legal provisions - such as the Nuclear Energy Act and the Environmental Protection Act - regulate the inspection and consultation procedure as part of the licensing process, even for installations with a low hazard potential.
For reasons of social responsibility and transparency, PSI involves the public informally and also provides information on the progress of the approval procedures, for example through media releases and regular updates on the PSI website.
Even if no formal public participation is required by law for a facility with a low hazard potential, PSI will set up a contact point for the public through which feedback can be submitted.
The PSI will hold information events at regular intervals at which the public can ask questions and make suggestions.
The collaboration between Copenhagen Atomics and PSI is based on the fact that both partners have a high level of expertise in molten salt reactors, albeit in different areas
Copenhagen Atomics is an expert in pumps and components for molten salts and for the production of high-purity salts.
PSI has internationally recognized expertise in the scientific processing of this technology. It also has great expertise in the construction of large-scale plants, in licensing and in the safe operation of nuclear plants. As part of the partnership, PSI is constructing an additional building (nuclear test facility) in which the Copenhagen Atomics experiment will be carried out under the strictest safety measures.
PSI is responsible for licensing and ensuring the safety of the experiment, while Copenhagen Atomics is responsible for financing and supplying the technical components of the experiment.
Both the PSI as a research institute and the Swiss supervisory authority (ENSI) enjoy an extremely high international reputation in the research, supervision and approval of nuclear facilities.
The costs for approval, construction, commissioning and implementation of the reactor experiment will be borne in full by Copenhagen Atomics.
This means that no Swiss taxpayers' money will be used for the construction of the nuclear test facility.
Currently planned is about four years. The milestones are as follows:
- Submission of a combined construction and operating licence for a nuclear test facility in accordance with Art. 20 para. 2 of the Nuclear Energy Act
- Granting of the combined construction and operating licence
- Construction and commissioning of the nuclear test facility
- Delivery of the experiment
- Cold tests of the experiment (functional tests without fuel and moderator)
- Hot tests of the experiment (functional tests with fuel and moderator)
- Criticality at zero power (self-sustaining chain reaction without significant thermal power)
- Gradual increase in power up to the set limit of the safety report
- Dismantling of the experiment
- Removal of the experiment from Switzerland.
In Denmark, there is no legal framework for the operation of nuclear facilities, i.e. no competent licensing and supervisory authority that could independently review and approve the construction and operation of such a test facility.
This is a goal that is being pursued in principle.
However, it depends heavily on the political framework conditions in Switzerland and, of course, on the success of the experiment.
For the tasks currently pending, scientists and technicians will initially be employed on temporary contracts and, where possible, contracts will be awarded to subcontractors in the region.
The PSI Center for Nuclear Engineering and Sciences (NES) and Copenhagen Atomics itself are linked to the global research community on molten salt reactors through numerous research projects and collaborations.
There is a lively exchange of information and knowledge. For example, PSI has been a partner in many EU-funded research projects on molten salt technology.
In general, international safety and environmental standards are important points of reference for the approval of nuclear facilities in Switzerland.
Although licenses are issued by national authorities such as the Swiss Federal Nuclear Safety Inspectorate (ENSI), they take into account international standards, such as those of the International Atomic Energy Agency (IAEA) or the Nuclear Energy Agency (NEA).
These standards help to ensure a high level of safety and integrate international best practice. For a plant with a low hazard potential, these standards play a subordinate role, but can still be included in the safety assessments.
At the General Assembly of the Swiss Nuclear Forum 2024, IAEA Director General Rafael Grossi encouraged Switzerland to contribute its vast knowledge of and experience with nuclear facilities to the use of nuclear energy.
The IAEA advocates a uniform, risk-based approach by national licensing and supervisory authorities: Installations with a proven low risk should require less extensive supervision.
Switzerland is a member of the Nuclear Non-Proliferation Treaty and is thus committed to banning the proliferation of nuclear weapons.
Together with the International Atomic Energy Agency (IAEA), the Swiss Federal Office of Energy (SFOE) carries out regular inspections of all Swiss nuclear facilities, checking the nuclear fuel inventories.
This ensures that no waste materials are diverted from the fuel cycle that would be suitable for the production of nuclear weapons. Such inspections also take place regularly at PSI.
The operator, i.e. PSI, monitors operations on an ongoing basis and reports to the Swiss Federal Nuclear Safety Inspectorate (ENSI).
This monitors compliance with the licensing requirements for nuclear facilities. It carries out regular inspections, checks the reports and ensures that all safety and operational requirements are met.
In the event of breaches of the licensing conditions, ENSI takes measures which, depending on the severity of the breach, can range from a written warning and operating conditions to temporary closure of the plant.
At the current stage of the licensing procedure, it is necessary to ensure that the planned facility is a low-risk nuclear facility.
The associated risk for the population is already legally defined and limited. The hazard potential is expected to be significantly lower than that of the existing nuclear facilities at the PSI.
This means that the emergency measures already taken or planned by PSI for incidents in existing nuclear facilities already cover the planned nuclear test facility.
The classification as a facility with low hazard potential ensures a high level of protection against incidents of both internal and external origin.
For a low-risk facility, this means that even in the case of highly improbable incidents (probability of up to 10-6) inside or outside the facility, the resulting radiation exposure of the population remains below the natural radiation exposure (< 1 mSv).
Yes, PSI will initially review the information provided by Copenhagen Atomics internally by specialist committees and external experts.
The supervisory authority ENSI will obtain additional expert opinions if necessary.
The licensing procedure for nuclear facilities includes a detailed safety report, risk analyses, radiation protection assessments and environmental impact assessments.
The Swiss Federal Nuclear Safety Inspectorate ENSI reviews safety reports, risk analyses and emergency plans for completeness and effectiveness. Simulations, technical tests and inspections are also carried out.
Emergency plans and possible incident scenarios are reviewed to ensure the safety and integrity of the plant and the protection of people and the environment.
In Switzerland, an environmental impact assessment is also required by law for installations with a low hazard potential.
The applicant must provide evidence of the expected radiation exposure, waste paths, emissions and other factors.
Technical safety measures protect the environment; at the same time, continuous measurements ensure strict radiological monitoring.
This is carried out within the framework of PSI's radiological monitoring systems, which have been tried and tested for decades.
Transportation is by truck.
As the planned project is an experiment, there is no waste in the legal sense.
All materials, both the fuel and the container, are still of interest to the owner Copenhagen Atomics and will continue to be used or examined in terms of materials technology.
It is therefore planned that the entire experiment will leave Switzerland again.
Only the operational waste from the radiation monitoring will therefore remain as radiological waste. This will be treated in the same way as the other operational waste from the PSI nuclear facilities and sent to the known disposal paths.
Yes, nuclear energy is fundamentally low in CO2 and this naturally also applies to molten salt reactors.
To date, there are no reliable figures on the production costs of energy generated with molten salt reactors.
However, molten salt reactors have the potential to be competitive, particularly due to their efficiency, safety and low fuel costs.
They could replace fossil fuels and serve as an alternative technology in combination with renewable energies.
The exact positioning compared to existing energy generation options also depends on technical progress and political framework conditions and is always location-dependent.
As the costs are borne entirely by Copenhagen Atomics, we cannot provide any information on the total costs or profitability.
Yes, Copenhagen Atomics will have to provide proof of insurance for various scenarios.
If the experiment is successful, the commercial benefits will accrue to Copenhagen Atomics.
However, the project will also deliver unique research results from which PSI and the international nuclear research community will benefit considerably.
If there is no patent protection, the research results are made available internationally.
Yes, there are research projects on fourth-generation reactors, including molten salt reactors, in various countries.
There are comparable projects in the USA and China in particular.
This project will enable PSI to construct a liquid salt reactor using the knowledge acquired to date and to test its suitability and safety.
Copenhagen Atomics is financing the construction of the nuclear test facility at PSI.
This facility will also allow PSI to conduct further valuable research that would not have been possible without this project.
In addition, at the request of the Swiss Federal Office of Energy, technology monitoring will take place during the project in accordance with Article 74a of the Nuclear Energy Act, whereby the safety and sustainability of advanced reactor concepts will be reviewed and evaluated.
The project also helps to train the next generation of radiochemists, nuclear scientists and engineers, which is the mandate of PSI's Centre for Nuclear Technologies and Sciences.
In turn, this project enables the Swiss regulatory authorities to become intensively familiar with advanced reactor technologies and to set international safety standards in this field.