Finnish report on nuclear safety : Finnish 7th national report as referred to in Article 5 of the Convention on Nuclear Safety

Abstract

Executive summary Finland signed on 20 September 1994 the Convention on Nuclear Safety which was adopted on 17 June 1994 in the Vienna Diplomatic Conference. The Convention was ratified on 5 January 1996, and it came into force in Finland on 24 October 1996. This report is the Finnish National Report for the Seventh Review Meeting in March/April 2017.

There are two nuclear power plants operating in Finland: the Loviisa and Olkiluoto plants. The Loviisa plant comprises of two PWR units (pressurised water reactors, of VVER type), operated by Fortum Power and Heat Oy, and the Olkiluoto plant two BWR units (boiling water reactors), operated by Teollisuuden Voima Oyj. In addition, a new nuclear power plant unit (PWR) is under construction at the Olkiluoto site. At both sites there are interim storages for spent fuel as well as disposal facilities for low and intermediate level nuclear wastes. Posiva, a joint company by Fortum and TVO, submitted a construction licence application for the spent nuclear fuel repository in the end of 2012. The construction licence was granted for Posiva by the Government in November 2015.

Finland is currently reviewing a construction licence application for Fennovoima Hanhikivi unit 1 in Pyhäjoki (VVER type design). Since the review is underway, Hanhikivi unit 1 is discussed in this report mainly with regard to the licensing process and siting (see Articles 7 and 17 and Annex 5).

Furthermore, there is a Triga Mark II research reactor, FiR 1 in Espoo licensed to VTT Technical Research Centre of Finland Ltd. The operating licence for the research reactor FiR 1 is valid until the end of 2023. However, VTT Technical Research Centre of Finland Ltd has decided to shut down and decommission the reactor earlier due to economical reasons. This will be the first decommissioned nuclear facility in Finland representing a new challenge for the utility and the regulatory body.

In this report, latest development in the various topics of the Convention on Nuclear Safety is described. Major safety reviews and plant modernisations are explained including safety assessment methods and key results. Safety performance of the Finnish nuclear power plants is also presented by using representative indicators. Finnish regulatory practices in licensing, provision of regulatory guidance, safety assessment, inspection and enforcement are also covered.

Major developments in Finland since the Sixth Review Meeting are as follows: updating of legislative and regulatory framework, implementation of the renewed regulatory guides at the operating nuclear power plants completed, periodic safety review carried out at the Loviisa nuclear power plant in 2015-2016, and IRRS follow-up mission (IAEA’s Integrated Regulatory Review Service) carried out in Finland. Furthermore, construction of the new nuclear power plant unit continued and progressed to the operating licence phase, one new unit has entered into construction licence phase and construction licence for Olkiluoto Spent Nuclear Fuel encapsulation and disposal facility was granted. Latest development in the various topics of the Convention on Nuclear Safety is described in relevant articles.

Finland continues the hosting and participation in the international peer reviews and the Government of Finland has requested the IAEA to carry out four OSART missions in Finland between 2017–2022: • Olkiluoto 1&2 OSART mission will be conducted from 27 February until 16 March 2017 • Loviisa NPP OSART mission would take place in March 2018. • Pre-Operational OSART mission for Olkiluoto 3 before the first fuel loading (according to current schedule in April 2018) • Pre-Operational OSART mission for Fennovoima (Hanhikivi unit 1) would take place in 2022.

In the report, the implementation of each of the Articles 6 to 19 of the Convention is separately evaluated. Based on the evaluation, the following features emphasising Finnish safety management practices in the field of nuclear safety can be concluded: • During the recent years Finnish legislation and regulatory guidance have been further developed and the revision of regulatory guide system was finalised in 2013. The overall revision of the regulatory guides took into account international guidance such as IAEA safety standards and WENRA (Western European Regulators’ Association) safety reference levels for existing reactors and safety objectives for new reactors. In addition, the lessons learnt from the TEPCO Fukushima Dai-ichi accident are taken into account. No deviation from the convention obligations has been identified in the Finnish regulatory infrastructure including nuclear and radiation safety regulations. • The revised regulatory guides were published at the end of 2013. The revised guides are applied as such for new nuclear facilities. For the existing facilities and facilities under construction separate facility specific implementation decisions are made. In the end of 2014 the licensees of operating NPPs submitted to STUK assessments on the fulfilment of the revised regulatory guides. In 2015, STUK evaluated the assessments and made decisions on how to further improve safety. Regular update and implementation of regulatory guides, particularly with regard to nuclear power plants in operation, are unique measures on the international perspective. • The licensees have shown good safety performance and rigorous safety management practices in carrying out their safety related responsibilities in the operation and modernisation of existing NPPs. During recent years, only minor operational events (INES 1 and below) have taken place and no major safety problems have appeared. The licensees’ practices are considered to comply with the Convention obligations. • Safety assessment is a continuous process and living full scope level 1 and 2 probabilistic risk assessment (PRA) practices are effectively used for the further development of safety. Periodic safety review of the Loviisa plant was carried out in 2015–2016, and the periodic safety review of the Olkiluoto plant was carried out in 2007–2009. The decisions how to apply the revised regulatory guides at the operating NPPs were made by STUK in 2015. Several plant modifications have been carried out at the operating NPPs during the recent years to further improve the safety. Some of these modifications are originating from the Fukushima Dai-ichi accident. • The resources of the Radiation and Nuclear Safety Authority (STUK) have been increased to meet the needs to oversee the construction of the new plants in Finland. The reports of the recent IRRS mission and follow-up mission have been published on STUK’s website and mission results have been and will be used to further improve regulatory guidance and practices. VTT Technical Research Centre of Finland Ltd supports effectively the regulatory body in the safety assessment work providing safety analysis capabilities and tools and performing safety analyses. There are also national research programmes which support and develop the competencies in nuclear safety and waste management of VTT as well as in the universities participating in the research programmes. • The Nuclear Energy Act was amended in 2015. The Act was revised to broaden STUK’s legal mandate to issue binding regulations. This was one of the recommendations from IRRS mission to Finland in 2012. Based on the amended Act, STUK published the new binding regulations concerning nuclear safety, security, emergency preparedness and waste management, as well as uranium and thorium mining in the beginning of 2016. Furthermore, based on changes in the Act the Government has to take into account the proposals included in the STUK’s statements when considering the conditions of the Decision-in-Principle and licences for nuclear facilities. • In January 2013 the Ministry of Employment and the Economy set up a working group to prepare a research and development strategy for the safe use of nuclear energy. The working group emphasized the importance of the research in the competence building. The Ministry of the Employment and Economy has started the implementation of the recommendations. In 2015 the Nuclear Energy Act was changed to ensure the financing for the enhancement of the nuclear safety research infrastructure.

The Sixth Review Meeting in 2014 identified some challenges and recorded some planned measures to improve nuclear safety in Finland. These issues are included and responded in this seventh national report of Finland. Some of these topics are discussed also below. These items were (in brackets the Articles, in which the issues are addressed): • regulatory oversight of existing NPP’s: ageing management (see Article 14) • challenges in new NPP construction project (Olkiluoto unit 3); oversight of contractors and subcontractors, operating licence application review, digital I&C (see Articles 10, 11, 12, 13, 18 and Annex 4) • preparation for the new build (see Annex 5) • maintaining and improving competence and responding to the growing needs for professional staff (see Articles 8 and 11) • continuous improvement of plant design: natural hazards, ultimate heat sink, I&C, electrical systems, spent fuel storage, emergency control room, replacement of diesel generators (see Articles 14, 17, 18 and Annexes 2, 3 and 4) • implementation of the action plan based on IRRS findings 2012, and follow-up IRRS mission in June 2015 (see Articles 7, 8, 10, 13, and Annex 6).

Still some of these issues require further development to enhance safety, i.e., including provision for plant ageing, reliability and safety demonstration of digital I&C and management of competence taking into account the new build projects and retirement of experts. Other important issues cover new technologies, security arrangements and the growing need for new research and development programmes. These are generic issues that require international attention in all countries using nuclear energy.

Implementation of the updated ageing management requirements is underway for NPPs in operation and some specific challenges to fulfil these requirements have been met. For instance the revised regulatory guide has a requirement on the availability and operability as well as monitoring the condition of spare parts. Inspections have revealed that the amount of spare parts can be inadequate for keeping the plant in a safe state also during either aged or obsoleted. Another challenge has to do with knowledge and resources allocated for ensuring appropriate ageing management programme at NPPs. Inspections have revealed that the licensees have challenges to implement knowledge management to ensure that in the event of personnel changes information and knowledge necessary for discharging the duties involved is transferred to the successors. Additional challenge is to conduct relevant research to both educate personnel and to identify new ageing mechanisms to develop new inspection or monitoring technologies to detect degradation early enough.

The expected lifetime of the existing nuclear power plants requires renewal of systems, structures and components and modernisation of technologies. The regulation of the existing nuclear power plants emphasises the management of ageing and the quality of plant operations. The modernisation of I&C and other systems at the Loviisa and Olkiluoto plants are either undergoing or under planning, and therefore extra care is needed to ensure that operational safety will be maintained notwithstanding the plant modifications. Operating experience has shown that special attention has to be paid on the meticulous planning and controlled implementation and testing of the plant modifications and STUK is following this in its regulatory inspections.

A generic lesson learned in Finland is that the closer nuclear power plants get to the end of their design lifetime, especially due to the current market price of electricity, more difficult it is for the licensees to make decisions to modernise or modify the NPPs. Instead of renewing a system or a component, modernisation may be rejected or a partial modification is planned resulting in ageing issues in the remaining parts. Finland has successfully applied periodic safety reviews (PSR) for the operating NPPs. Practice has been that the licensee is obliged to demonstrate that the safety of the operations can be ensured and improved also during the next 10 years, and to do that the licensee has to commit to make safety improvements including major modernisations to address ageing of SSCs.

The retirement of large age groups in Finland has been affecting public administration and industry throughout, including STUK, utilities and the spent fuel management company Posiva as well as organisations providing technical support and education to them. The plans for a new NPP construction project and the above mentioned challenges and activities require additional resources and efforts from the nuclear power utilities and regulatory body as well as from technical support organisations. Thus, ensuring an adequate national supply of experts in nuclear science and technology and ensuring high quality research infrastructure are continuous challenges in Finland. For the moment, STUK has adequate resources to fulfil its oversight responsibilities. However, resources used for developing STUK’s own activities may be considered to be occasionally insufficient.

The Government has been decreasing STUK’s budget during the past years mostly due to reorganisation of funding and conduct of research in the government organisations. While oversight activities are charged in full from the licensees and nuclear safety research programmes are funded via waste management fund, budget cuts have not impacted the nuclear safety research or resources needed for the regulated activities. However, due to budget cuts STUK has partly terminated and also decreased significantly its radiation safety research (e.g. biological effects of radiation, biodosimetry). Since radiation safety research activities have been contributing to the maintenance and development of know how in Finland, STUK has established a national radiation safety research programme in co-operation with all universities in Finland to ensure that radiation safety research will be continued in Finland.

Since the interest in nuclear power in Finland is increasing, communication and information sharing with media and the general public on nuclear and radiation safety has become an increasingly important success factor for STUK and utilities. Regulatory processes and decisions have to be clear and understandable to general public. Due to the challenge, STUK has initiated a strategic communication development project in spring 2016 to address both changing communication environment and the use of modern communication tools. In addition, STUK has also initiated a project to develop its crisis communication capabilities. This work is based on the experience on recent events as well as past emergency exercises.

Actions taken as a result of the TEPCO Fukushima Dai-ichi accident

Following the accident at the Fukushima Dai-ichi nuclear power plant on the 11th of March in 2011 (TEPCO Fukushima Dai-ichi accident), safety assessments were initiated in Finland immediately. In order to ensure nuclear safety, the Ministry of Employment and the Economy requested STUK to carry out a study on how the Finnish NPPs have prepared against prolonged losses of electric power supply and ultimate heat sink and extreme natural phenomena. Based on the results of the assessments conducted in Finland, it was concluded that no such hazards or deficiencies have been found that would require immediate actions at the Finnish NPPs. However, areas where nuclear safety can further be enhanced were identified, and accordingly, Finnish National Action Plan how to address these areas was created. The experiences from the TEPCO Fukushima Dai-ichi accident were also addressed in the renewed regulation and Finnish Regulatory Guides (YVL Guides) and in the nuclear safety research programme (SAFIR), see Articles 7 and 8.

In addition to the periodic safety reviews carried out for the nuclear power plants, an extraordinary review of site related issues was performed after the TEPCO Fukushima Dai-ichi accident in connection with the so called European stress tests. Assessment of the safety margins and effects of exceeding the design basis values have been available and utilised for all identified relevant hazards (including extreme weather conditions) in connection with external events probabilistic risk assessments (PRA) which are mandatory for the Finnish NPPs. The stress tests did not reveal any new site-related external hazards or vulnerabilities of the plants to external events. No need for immediate action was recognised, but some additional studies of external hazards and feasibility studies for plant modifications to improve robustness against external events were found justified (see Article 17). The following examples of safety improvements and additional analyses of external events can be mentioned: enhanced protection against high seawater level at the Loviisa NPP, detailed structural analysis of spent fuel pools to demonstrate integrity of the pools in the case of an earthquake with consequential boiling in the pools and seismic walk-downs of the fire extinguishing water system at the Olkiluoto NPP following with some improvement measures.

The systems needed for residual heat removal from the reactor, containment and spent fuel pools require external power at both Finnish NPPs. At both sites, the ultimate heat sink is the sea. A reliable supply of electrical power to the systems providing for basic safety functions at the Finnish NPPs is ensured by the Defence-in-Depth (DiD) concept. As a result of multiple and diversified electrical power sources at different DiD levels, the probability of loss of all electrical supply systems is considered very low at the Finnish NPPs. However, as a result of the studies made after the TEPCO Fukushima Dai-ichi accident, further changes are under planning or implemented at the both NPPs (see Articles 6 and 18). For example at the Loviisa NPP the independent air-cooled cooling units have been installed for decay heat removal from the reactor core and from the spent fuel pools in case of the loss of sea as an ultimate heat sink. These cooling units were considered already before the TEPCO Fukushima Dai-ichi accident due to the increased risks related to transporting of oil on the Finnish Gulf. Safety improvements at the Olkiluoto units 1 and 2 include ensuring cooling of the reactor core in case of total loss of AC systems, ensuring operation of the auxiliary feed water system pumps independently of availability of the sea water systems, and diverse cooling of the spent fuel pools. The emergency diesel generators will be replaced within the next few years. The new emergency diesel generators will be provided with alternative air and seawater cooling, while the existing diesels have only seawater cooling.

A comprehensive severe accident management (SAM) strategy has been developed and implemented at the operating Finnish NPPs during 1980’s and 1990’s after the accidents in TMI and Chernobyl (see Annexes 2 and 3). These strategies are based on ensuring the containment integrity which is required in the existing national regulations. STUK has reviewed these strategies and has made inspections in all stages of implementation. As a result of the studies made after the TEPCO Fukushima Dai-ichi accident, no major changes at the plants are considered necessary for severe accident management. However, the licensees are expected to consider ensuring the cooling of spent fuel pools in the SAM procedures (see Article 19). In addition, there are many actions related to the update of the emergency plans (see Article 16). Both NPPs were required to clarify and update their emergency preparedness plans with respect to issues like the possibility of several reactor units’ simultaneous accident, evaluation of the number and the suitability of emergency response personnel to their duties, management of access control and contamination control in the case when the normal arrangements are out of function and restoring the access routes and connections to the site in case of massive destruction of the infrastructure.

Concerning the off-site emergency preparedness and response (see Article 16), no needs for major changes were identified. However, some improvements were identified and implemented that are for instance improved accessibility to the site in case of extreme natural hazards, ensured sufficient amount of radiation protection equipment and radiation monitoring capabilities for rescue services and improved the communication arrangements between emergency centers of NPPs, STUK, and Rescue Service. In 2014 Loviisa NPP exercised for the first time a two reactor unit’s simultaneous accident scenario. Furthermore, during the national full command post exercise OLKI-14 actions and decision making of the intermediate phase of the severe accident were exercised for the first time.

Most of the Fukushima Dai-ichi related safety improvements presented in the Finnish national action plan have already been implemented. A few ongoing measures will still be completed in the next few years. Further information related to the actions taken in Finland following the accident at the Fukushima Dai-ichi nuclear power plant are described in more detail under Articles 16, 17, 18, 19 and Annexes 2, 3 and 4.

The challenges identified by the Special Rapporteur in the Sixth Review Meeting

How to minimize gaps between Contracting Parties’ safety improvements? The Finnish policy is to participate actively in the international work on developing safety standards and adopt or adapt the new safety requirements into national regulations. STUK participated WENRA’s work on the update of the Safety Reference Levels after the Fukushima accident and most of the updated Reference Levels were already taken into account in the finalisation of the revised YVL guides. In addition, Finland has bilateral agreements with several foreign countries and regulatory bodies. See more details under Article 7 and Annexes 2, 3 and 6.

How to achieve harmonized emergency plans and response measures? Nordic countries have published two joint documents that detail the cooperation arrangements in case of an radiological emergency. Nordic Manual and Nordic Flag Book ensure that the response to any nuclear or radiological emergency in Nordic countries is harmonised and consistent between the countries. Furthermore, Finland participates actively in the international cooperation in the field of emergency preparedness, such as IAEA, OECD/NEA and EU/EC (WENRA and HERCA). See more details under Article 16.

How to make better use of operating and regulatory experience, and international peer review services? Finland supports activities to improve peer review services and has participated in the development of IAEA’s peer review services (e.g. IRRS, IPPAS and the OSART missions). Finland continues both hosting and providing experts to the international peer reviews. The latest peer reviews in Finland are described in Annex 6. STUK has also participated in co-operation between international organisations such as the IAEA, the OECD/NEA and the EU (Clearinghouse), which exchange information on safety issues, operating events and regulatory experience. Other forums that STUK uses to obtain information are WENRA, MDEP and its working groups, the VVER Regulators’ Forum as well as some bilateral agreements. See more details under Articles 8 and 19 and Annex 6.

How to improve regulators’ independence, safety culture, transparency and openness? The regulatory control of the safe use of radiation and nuclear energy is independently carried out by STUK. STUK’s role and responsibilities have been assessed by a peer reviews (IRRT mission in 2001, follow-up in 2003 and IRRS mission in 2012, follow-up in 2015). STUK’s Safety and Quality Policy was fully renewed in 2014 as a result of the recommendation from the IRRS mission. STUK has also updated its management system and included selfassessment of safety culture into annual self-assessment programme. The IRRS mission also recommended that the Government should seek to modify the Nuclear Energy Act so that the law clearly and unambiguously stipulates STUK’s legal authorities in the authorisation process for safety. Based on the recommendation, the Act was amended in 2015 to broaden STUK’s legal mandate to issue binding regulations. Furthermore, the Government has to take into account the proposals included in the STUK’s statements when considering the conditions of the Decision-in-Principle and licences for nuclear facilities. See more details under Articles 8 and 10.

How to engage all countries to commit and participate in international cooperation? STUK participates in international cooperation in several working groups of the IAEA, the OECD/NEA and the EU. For example, the OECD/NEA/CNRA working groups WGOE (Operating Experience) and WGRNR (Regulation of New Reactors) improve nuclear safety by sharing experience and lessons learnt from nuclear installations in operation and under construction. Other forums that STUK uses to obtain information are WENRA, MDEP and its working groups, the VVER Regulators’ Forum as well as some bilateral agreements. For example, exchange of information between Rostechnadzor and STUK on the operation of the Kola and Leningrad nuclear power plants and of Finnish nuclear power plants is an ongoing activity. The similar information exchange is arranged also to Sweden (SSM) and France (ASN). Furthermore, Finland has bilateral agreements with Sweden, Norway, Russia, Ukraine, Denmark and Germany on early notification of nuclear or radiological emergencies and exchange of information on nuclear facilities. In addition, STUK has bilateral arrangements with several foreign regulatory bodies, which cover generally the exchange of information on safety regulations, operational experiences, waste management etc. Such an arrangement have been made with NRC (USA), ASN (France), FANR (United Arab Emirates), NSSC and KINS (Republic of Korea), TAEK (Turkey), ENSI (Switzerland), SUJB (Czech Republic), Rostechnadzor (Russian Federation), CNSC (Canada), AERB (India), ONR (Great Britain), HAEA (Hungary), NNR (South Africa), NRA (Japan) and SSM (Sweden). STUK has also formed a strategic partnership with King Abdullah City for Atomic and Renewable Energy (K.A.CARE) to develop the necessary infrastructure for the establishment of a national authority dedicated to regulate and monitor nuclear safety in Saudi Arabia. See more details under Annex 6.

Consideration of the Vienna Declaration on Nuclear Safety

The Vienna Declaration on Nuclear Safety was adopted by the Contracting Parties by consensus at the Diplomatic Conference on 9 February 2015. The Vienna Declaration contains three principles to guide the Contracting Parties.

The first principle concerning the safety goal for new nuclear power plant design, siting, construction and operation is included in the Finnish regulations (see Articles 17 and 18). Furthermore, the Nuclear Energy Decree stipulates that the release of radioactive substances arising from a severe accident at a nuclear power plant shall not necessitate large scale protective measures for the population nor any long-term restrictions on the use of extensive areas of land and water. In order to limit the long term effects, the limit for atmospheric releases of cesium-137 is 100 terabecquerel. The possibility of exceeding the set limit and of a release in the early stages of an accident requiring measures to protect the population shall be extremely small.

Regarding the second principle, on the implementation of safety improvements at the operating NPPs to meet, as far as reasonably practicable, the safety goal of the first principle, Finnish regulations state that periodic safety review (PSR) shall be conducted at least every ten years. In addition, the Nuclear Energy Act states that the safety shall be maintained as high as practically possible and for further development of safety, measures shall be implemented that can be considered justified considering operating experience and safety research and advances in science and technology. Hence, the implementation of safety improvements has been a continuing process at both Finnish NPPs since their commissioning. The most significant plant modifications and modernisation projects carried out at the Finnish NPPs during the plant life time including backfitting of severe accident management systems during 1980’s and 1990’s are described in Annexes 2 and 3.

Regarding the third principle of the Vienna Declaration requiring that national regulations need to take into account the relevant IAEA safety standards and, as appropriate, other good practices, the Finnish nuclear safety regulations are regularly updated taking into account operating and construction experience, safety research and advances in science and technology. The overall revision of the regulatory guides in end of 2013 took into account international guidance (e.g. IAEA safety standards and WENRA safety reference levels) and the lessons learnt from the Fukushima Dai-ichi accident.

In conclusion, Finland has implemented the obligations of the Convention and also the objectives of the Convention, including the principles of the Vienna Declaration on Nuclear Safety, are complied with. Safety improvements have been implemented at the Loviisa and Olkiluoto plants since their commissioning. Legislation and regulatory guidance have been further developed. Additional safety assessments and implementation plans for safety improvements have been made at the Loviisa and Olkiluoto plants based on the lessons learnt from the Fukushima Dai-ichi accident. IRRS mission (IAEA’s Integrated Regulatory Review Team) was carried out in October 2012 and the follow-up mission in 2015. STUK has been implementing its action plan for improvement on the basis of the IRRS missions results and the self-assessment. There exists no urgent need for additional improvements to upgrade the safety of the Finnish nuclear power plants in the context of the Convention.