IRRS Mission 2021: IAEA approves ENSI as an independent and progressive regulatory authority

Swiss nuclear safety oversight complies with the internationally applicable standards of the IAEA regulatory framework. This is the outcome of the IRRS mission of the International Atomic Energy Agency that concluded on Friday. ENSI will be implementing the improvement suggestions of the team of experts with an own package of measures.

Petteri Tiippana, Director General of the Finnish Radiation and Nuclear Safety Authority STUK, summarised the results of the IRRS mission: “Based on the mission and the outcomes we think that ENSI is a mature, competent and independent regulator and with that fully capable of fulfilling its mandate in Switzerland”. Since 18 October 2021, international experts under his leadership have been able to assemble an accurate overview of the Swiss regulatory system and ENSI’s work. The concluding meeting took place at ENSI’s headquarters in Brugg on 29 October 2021.

The Integrated Regulatory Review Service (IRRS) is backed by the International Atomic Energy Agency (IAEA) and is a service for its member states to help improve and develop nuclear safety worldwide.

IRRS Mission to Switzerland: the Background

The 2021 IRRS mission took place in Switzerland from 18 to 29 October with the aim of reviewing nuclear oversight. Among other things, the team of experts assembled by the International Atomic Energy Agency (IAEA) interviewed ENSI employees, nuclear plant operators, representatives of various national authorities and organisations, met with representatives of a Swiss NGO and accompanied ENSI specialists during inspections in regulated installations.

“On the one hand, this external assessment ensures that our oversight work is putting the IAEA regulations into practice. On the other hand, recommendations from international experts on issues highlighting room for improvement are valuable for our work,” said ENSI Director General Marc Kenzelmann on 18 October 2021 at the start of the IRRS mission.

An IRRS mission essentially comprises two parts: firstly, the preliminary self-assessment of the national regulatory system and, secondly, the review during the mission by a team of international experts assembled by the IAEA.

The IRRS mission in Switzerland prior to this took place in 2011, the corresponding follow-up review mission in 2015. Pursuant to Art. 2 para. 3 of the ENSI Ordinance, ENSI is obliged to undergo an international review every ten years.

The team of experts confirmed that the Swiss regulatory system, including the regulatory framework, contributes to nuclear safety. Nevertheless, the IRRS mission also made recommendations. For example, that in view of the challenges ahead – namely the decommissioning of nuclear power plants, radioactive waste disposal, and the long-term operation of nuclear power plants – Switzerland requires a national strategy to be able to maintain or build up expertise in the nuclear sector in the medium and long term and in this way remain able to continue to ascertain nuclear safety.

ENSI also received good marks from the IRRS team for its regulatory and safety culture. The backfitting requirements for the continuous improvement of safety in the nuclear installations and the related regulatory policy of ENSI were positively highlighted. The notes and recommendations given to ENSI concern, for example, the updating of the ENSI regulatory framework and the procedures for carrying out inspections.

“We would like to thank the IRRS team that carried out the mission on behalf of the IAEA,” said Marc Kenzelmann, ENSI Director General upon conclusion of the mission. “The completed international review will help us to further strengthen nuclear safety in Switzerland. We will treat the recommendations of the IRRS team with due seriousness”.

Package of measures: ENSI implements recommendations

The official final report of the IRRS mission is expected to be delivered during the coming months which ENSI will then publish it on its website.

The recommendations and instructions of the mission are not legally binding on Switzerland. However, ENSI will work through them within the framework of an action plan. A follow-up mission on the part of the IAEA will assess how the improvement suggestions have been implemented in the coming years.

The press release of the IAEA concerning the IRRS mission to Switzerland:

1 November 2021 | Brugg, Switzerland — IAEA Mission Says Switzerland Is Committed to a High Level of Safety, Sees Areas for Further Enhancement
An International Atomic Energy Agency (IAEA) team of experts said Switzerland is committed to maintaining and strengthening its regulatory framework for nuclear and radiation safety, as the country moves ahead with its plans to phase out nuclear power.

The team added that a key challenge is to keep and to build new safety competence for the future by evaluating anticipated gaps in expertise and in identifying actions required to fill them.

The Integrated Regulatory Review Service (IRRS) team concluded a twelve-day mission to Switzerland on 29 October. The mission was conducted at the request of the Government of Switzerland and hosted by the Swiss Federal Nuclear Safety Inspectorate (ENSI), the national regulatory body for safety and security of nuclear facilities.

Using IAEA safety standards and international good practices, IRRS missions are designed to strengthen the effectiveness of the national regulatory infrastructure, while recognizing the responsibility of each country to ensure nuclear and radiation safety.

The 20 member team, comprised of 17 senior regulatory experts from 15 countries, as well as 3 IAEA staff members, reviewed facilities and activities regulated by ENSI. This included the four Swiss nuclear reactors which generate 35% of the country’s electricity, one operational research reactor and a national interim storage facility for radioactive waste. Switzerland decided in 2011 to phase out nuclear power and, in 2017, Swiss citizens voted in a referendum endorsing a new energy law to promote renewable energy and to approve a ban on new nuclear power plants.

Activities covered during the safety review included emergency preparedness and response, transport, decommissioning, occupational exposure control, environmental monitoring and public exposure, and the safety interface with nuclear security. The IRRS Team also reviewed the licensing process and regulatory guidelines for the ongoing plans for constructing a deep geological waste repository. The mission also used the opportunity to exchange information on national regulatory implications of the COVID-19 pandemic.

The team visit was part of the  second IRRS mission cycle to be held in Switzerland, the first was in 2011, with a follow-up in 2015, which also had the same scope to review facilities and activities regulated by ENSI.

“Switzerland has a mature regulatory infrastructure for nuclear safety and radiation protection. As the country phases out its national nuclear power programme, its main challenge at the national level  is to maintain and build the competence of parties with safety responsibilities, that is, ENSI and the nuclear industry including NPP licensees,” said IRRS team leader Petteri Tiippana, Director General of the Finnish Radiation and Nuclear Safety Authority – STUK – who led the team.

“ENSI welcomes an IAEA review of our oversight work to better understand the degree of implementation of IAEA safety standards in Switzerland,” said Marc Kenzelmann, ENSI Director General. “The outcomes of the mission will strengthen our regulatory framework by setting out the precise areas to focus on within ENSI’s continuous improvement programme.”

During the mission, the team conducted interviews with management and staff from ENSI and the nuclear facilities, as well as from other national authorities and one non-governmental organization. The team also accompanied ENSI during their inspection and oversight activities at regulated facilities.

The team identified good practices in the area of safety culture. ENSI continuously improves its internal safety culture and promotes the proactive safety culture of licensees through periodic focus groups.

Good performances have been also acknowledged, including:
– The role of ENSI in implementing the regulatory policy and associated requirements for continued safety improvements at nuclear power plants.
– The collaborative dialogue among all Federal and Cantonal authorities involved in the licensing process of nuclear facilities.
– The periodic security background tests for ENSI’s staff, including evaluation of a potential lack of impartiality.

The IRRS Team also identified several recommendations and suggestions to further enhance the Swiss regulatory system and the effectiveness of the regulatory functions in line with IAEA safety standards, including:
– The Government should set up legal provisions to allow for the prosecution of a licensee in addition to an individual.
– ENSI should update its procedures for clarifying the role of inspectors in the enforcement process, including in relation to the immediate corrective actions inspectors are authorized to take.

The final mission report will be provided to the Government of Switzerland in about three months. Switzerland plans to make the report public.


General information about IRRS missions can be found on the IAEA website. IRRS are used to advise Member States on ways to strengthen and enhance the effectiveness of national regulatory frameworks for nuclear, radiation, radioactive waste and transport safety while recognizing the ultimate responsibility of each State to ensure safety in these areas.

The IAEA Safety Standards provide a robust framework of fundamental principles, requirements, and guidance to ensure safety. They reflect an international consensus and serve as a global reference for protecting people and the environment from the harmful effects of ionizing radiation.