The energy policy goals of Slovenia are to ensure a reliable, safe and competitive energy supply in a sustainable manner by ensuring a low carbon transition and achieving United Nations sustainable development goals. Future development of the energy industry is centralized among three general and inextricably linked pillars of energy policy, namely: climate sustainability, energy supply security and competitiveness.

In 2020, Slovenia prepared the Long-term Strategy for the next 30 years, which includes an analysis of different scenarios for the contribution of the European Union to meeting its own and Member States’ commitments under the United Nations Framework Convention on Climate Change and the Paris Agreement. Entered into force on 24 December 2018, EU Member States were required to prepare integrated national energy and climate plans (NECPs) that cover the five dimensions of the energy union for 2021–2030, according to the drafted governance of the energy union and climate action rules. In Slovenia, the Long-term Strategy and the Integrated NECP were prepared in harmony, where the Slovenian NECP was adopted by the Government on 27 February 2020.

The Energy Concept of Slovenia (ECS) serves as the basic development document in the energy field that will define objectives for the reliable, sustainable and competitive energy supply for the next 20 years (and tentatively up to year 2060). The ECS is drafted based on the projections of the country’s economic, environmental and social development and the adopted international commitments and is to be adopted through a resolution by the National Assembly on the Government’s proposal. The Ministry of Infrastructure estimates that the revised Resolution on the Energy Concept of Slovenia (ReECS Motion) could be prepared before mid-2021.

The objective of reducing greenhouse gas emissions affects the share of renewable energy sources in the final consumption of energy. Currently, Slovenia’s national objective is set at 27% by 2030 and confirmed by the Slovenian Development Strategy 2030. According to the rating of the World Energy Council (World Energy Trilema Index), Slovenia received the highest assessments in energy security in the world from 2016 to 2018.

Slovenia will strive to reduce the use of and dependency on fossil energy sources to the greatest extent possible, by gradually phasing out their use with great emphasis on increasing the efficient use of energy and greater use of renewable and low carbon sources. Considering decarbonization projections, the share of renewable energy sources in energy balances is projected to increase. Slovenia also maintains projects of common interest, including electricity clusters with high voltage power lines with Croatia, Hungary and Italy, which will contribute to the optimization of electricity trade, energy supply and increase electricity interconnectivity. Moreover, the Slovenian and Croatian electricity transmission network operators are implementing a project of common interest in the field of smart networks, which is co-financed by Connecting Europe Facility.

Slovenia has limited energy reserves (see Table 2). The proven and recoverable reserves of low quality brown coal and lignite amount to about 371 million tonnes. There are no proven crude oil and natural gas liquids recoverable reserves. The estimated hydropower reserves of Slovenia are up to 9.1 TWh per year, of which 4.3 TWh are already exploited. The country is connected to three gas pipelines, from Algeria, Austria and the Russian Federation.

TABLE 2. ESTIMATED ENERGY RESERVES

Source: World Energy Council, data for 2015 [1].

^a Coal, including lignite (million tonnes): proven recoverable reserves, the tonnage within the proven amount in place that can be recovered in the future under present and expected local economic conditions with existing available technology.

^b Crude oil and natural gas liquids (million tonnes; oil shale, natural bitumen and extra heavy oil are not included): proven recoverable reserves, the quantity within the proven amount in place that can be recovered in the future under present and expected local economic conditions with existing available technology.

^c Natural gas (billion cubic metres): proven recoverable reserves, the volume within the proven amount in place that can be recovered in the future under present and expected local economic conditions with existing available technology.

^d Reasonably assured resources under US $130/kg U (tonnes).

^e Hydropower (TWh per year): technically exploitable capability, the amount of the gross theoretical capability that can be exploited within the limits of current technology.

^f —: data not available.

A significant share of Slovenian industrial production is energy intensive, such as steel production, aluminium, chemicals, pulp or paper and building materials. Yet, overall energy demand is decreasing gradually; in 2018, industrial energy demand accounted for 28% of total energy consumption. The largest share was in transport, standing at 40%. High energy consumption in industry and transport is also reflected in high energy use per unit of GDP, when compared to other Western EU countries. Energy use per capita is lower than the average for EU Member States.

TABLE 3. ENERGY STATISTICS

Source: Statistical Office of Republic of Slovenia; 2020

The following services are considered public service obligations: transmission system operator, distribution system operator, electricity distribution and market operator. The transmission and distribution companies are required to ensure access to the electricity network in a transparent and non-discriminatory manner following the principles of regulated third party access. The information on distribution and transmission networks traffic is public. The markets for electricity and gas in Slovenia were opened to all non-household customers in July 2004, representing a volume of market opening of 75% and 90%, respectively. Both markets have been fully open since 1 July 2007.

The creation of a market operator is one of the obligatory elements of the Energy Act, and one of the fundamental conditions for opening up the electricity market. The operation of the organized electricity market and the rights and duties of the market operator were in detail set in the new Rules on the Operation of the Electricity Market in 2019, which implement the requirements of the first stage of harmonisation of the Electricity Balancing Guideline Regulation. For the implementation of the public utility service relating to the organisation of the electricity market and activities in the Slovenian energy field connected with stimulating the use of renewable sources and the efficient use of energy in 2001 the company Borzen was established. As Power Market Operator Borzen provides and facilitates coordinated operation of the Slovenian electricity system. It is responsible for executing the activities of balance scheme management, recording of closed contracts, elaboration of indicative operating schedule, imbalance settlement and financial settlement of transactions, all connected with the aforementioned activities.

Within the “Centre for RES/CHP support” Borzen acts as support scheme operator for the generation of energy from renewable energy sources (RES) and highly efficient cogeneration of heat and power (CHP). The support scheme is financed via a supplement to the electricity price. Installations using renewable energy generation sources or waste and cogeneration units are eligible for qualified producer status. Yet, producers must meet environmental acceptability standards. Power plants are divided into four groups, depending on the installed power: micro power plants (up to 50 kW); small power plants (from 50 kW to 1 MW); medium power plants (from 1 MW to 10 MW); and large power plants (above 10 MW). The feed-in tariff scheme and premium schemes are set by the Government to stimulate production of electricity from renewable energy sources and combined heat and electricity power plants. The national target, a 39.3% share of renewable electricity in the gross final energy demand by 2020, is set in the National action plan for renewable energy between 2010–2020.

Borzen also promotes the development of the Slovenian electricity market and market mechanisms in accordance with EU guidelines and contributes significantly to the proper functioning of the Slovenian power system, alignment of Slovenian and European legislation and integration of the Slovenian electricity market to the integrated European electricity market.

In accordance with the provisions of the legislation, The Energy Agency is established as the national energy regulator as responsible for preparation and compliance of market rules. The regulator's task is providing the circumstances for development of competitiveness and ensuring its operation by taking into account the requirements for sustainable, reliable and high-quality supply.

The Energy Agency shall, acting under public authorisation, carry out the administrative and other tasks specified in the Energy Act, EU regulations, which determine the competences of the national energy regulators, or in general act of the agency adopted on the basis of the energy legislation. The tasks can be summarized in the following areas:

• regulation of the network activities, which covers economic regulation of all electricity and gas system operators and the regulation of the network with respect to issuing consents to the general acts,

• regulation of the supply of heat and other energy gases,

• ensuring a reliable supply of natural gas,

• promoting the production of electricity from renewable sources and cogeneration,

• promoting efficient use of energy,

• monitoring of electricity and natural gas market,

• supervising the providers of energy operators' activities,

• protecting the rights of consumers.

The Energy Agency in performing its task establishes conditions that encourage regulated companies to improve performance and investments. It supervises and monitors the implementation of regulated activities by determining the right balance between the quality of supply and prices for regulated services and promotes the efficient use of existing infrastructure. It ensures the transparency and openness of the regulatory process. It cooperates in the preparation and amending of the rules and general acts regulating market operation, and promotes transparency and non-discrimination.

The Energy Agency is continuously improving the regulation of the energy market in accordance with the best professional practice. It participates in the creation of the internal energy market at regional level.

Slovenia has fairly diversified primary sources for electricity production. In 2018, Slovenia had 3773 MW of total installed electricity capacity, 688 MW of which was provided by the Krško nuclear power plant (NPP) in addition to 1343 MW provided by hydropower plants, 1515 MW provided by thermal power plants and 227 MW provided by other power plant facilities (see Table 4). Total gross electricity production in 2018 amounted to 16331 GWh, of which 5776 GWh was produced from nuclear power plant, 4893 GWh from hydropower plants, 5400 GWh from thermal power plants and 255 GWh from solar and wind power plants.

TABLE 4. ELECTRICITY PRODUCTION AND INSTALLED CAPACITIES

Source: Statistical Office of Republic of Slovenia; 2020

In Slovenia, there are eight power generating companies, each with one main power station, with the exception of hydropower, where one company operates a chain of power plants on a single river system. Most of the major players in electricity production are owned by the two parent companies, Holding Slovenske Elektrarne (HSE) and GEN Energija. HSE also has majority ownership of the lignite mine in Velenje. Nuklearna Elektrarna Krško (NEK), on the other hand, is owned in equal shares by the Slovenian and Croatian legal successors of the founders of the power plant. On the Slovenian side, this is the company GEN Energija, which is 100% state owned.

The electric power transmission network of Slovenia is operated by company Slovenian Electric Utilities (ELES) whose main responsibility is to ensure best possible and most transparent use of the existing transmission grid management, operational reliability and security (as defined in the Energy Act). The Slovenian electrical power system is interlinked with the synchronous transmission grids of neighbouring states and integrated into the European network. There are three voltage levels in the transmission grid (400 kV, 220 kV and 110 kV), as well as corresponding transformer substations. The transmission network of Slovenia is presented in Fig. 1, along with generating capacities.

FIG. 1. Transmission network of Slovenia.

In 2018, final energy consumption (FEC) in Slovenia was around 208.2 PJ. The largest consumer was the transport sector (40%), followed by manufacturing and construction (28%), households (21%) and other use, including agriculture (11%). 

TABLE 5. ENERGY RELATED RATIOS

Source: Statistical Office of Republic of Slovenia; 2020

Slovenia has had one nuclear power plant in commercial operation since 1983, the Krško NPP. Construction started in 1975 and it was connected to the grid in 1981, entering commercial operation in 1983. In 2001, its steam generators were replaced, and the plant was first uprated by 6%, followed by an additional 3% uprate. Its operational life was designed to be 40 years but was extended to 60 years in 2012. The Krško NPP is a pressurized water reactor of 696 MW(e), delivered and constructed by Westinghouse and jointly owned with Croatia. The reliable operational and safety record of the Krško NPP complies with all international standards and the highest safety requirements. The safety status of the plant is supervised by the Slovenian Nuclear Safety Administration (SNSA) as well as by international expert missions organized by the IAEA, the European Union and the World Association of Nuclear Operators (WANO), among others.

After modernization in 2001 and transition to an 18 month fuel cycle in 2005, it can produce over 5.8 TWh in a year without outage and around 5.4 TWh in a year with outage. So, in accordance with the bilateral treaty on the Krško NPP, between 2.7 TWh and 2.9 TWh of electricity is available for the Slovenian market annually. In addition to the share of the electricity produced, the Krško NPP is also characterized by extremely high reliability. It can operate for 510 days without shutdown, ensuring stability of the electrical power system and reliable supply to customers.

The contract between the governments of Slovenia and Croatia on the regulation of status and other legal relations connected to investment in the Krško NPP, the use and decommissioning of the NPP, in addition to the memorandum of association all took effect on 11 March 2003. The basic capital of the Krško NPP is divided into two equal shares owned by the partners GEN Energija and HEP (Hrvatska Elektroprivreda). The Krško NPP produces and supplies electricity exclusively in favour of the two partners, who each have the right and obligation to 50% of its total output.

The organizational structure of the Krško NPP is shown in Figs 2 and 3.

FIG. 2. External organizational structure.

FIG. 3. Organizational structure of the Krško nuclear power plant.

Table 6 provides the status of the Krško NPP, and more data can be found on the Krško NPP home page (www.nek.si/en) (see Fig. 4).

TABLE 6. STATUS OF THE KRŠKO NUCLEAR POWER PLANT

Source: IAEA – Power Reactor Information System (PRIS)

Fig. 4. Location of the Krško nuclear power plant.

The most important performance indicators are displayed in Table 7.

TABLE 7. SAFETY AND PERFORMANCE INDICATORS

Krško NPP’s operational life was originally designed for 40 years, until 2023. However, because of reliable maintenance and the replacement of major vital components, the Krško NPP is in good condition. Based upon these parameters, the Krško NPP launched its ageing management programme in 2008, which serves as a basis for plant life extension. On 20 June 2012, the SNSA issued a decision approving the modifications, which will enable long term operation of the Krško NPP. An approved ageing management programme of the Krško NPP is a precondition for the extension of its operation beyond 2023. In addition, a comprehensive second periodic safety review was approved in 2013, and a third one will be conducted in 2022 and 2023.

Following the Fukushima Daiichi accident, the Krško NPP analysed lessons learned and prepared the Safety Upgrade Programme (SUP), which was approved by the SNSA. The Krško NPP's SUP consists of a series of safety improvements, such as installing alternate bunkered systems for injecting cooling water into primary and secondary systems, installing an alternate system for cooling the spent fuel pool, installing a filtered venting system, replacing active hydrogen recombiners with passive ones, installing an emergency control room and independent instrumentation qualified for severe accidents, enhancing flood protection of the plant, etc. The Krško NPP's SUP, which is still underway, is scheduled to be completed before the end of 2021.

Furthermore, the precondition for potential operation after 2023 includes maintenance of operating equipment, well trained operators and a good safety culture of all employees. All the above-mentioned conditions should be fulfilled if operation of the NPP will be extended beyond 2023.

The Jožef Stefan Institute (IJS) is the leading Slovenian research organization. It is responsible for a broad spectrum of basic and applied research in the fields of natural sciences and technology. The staff of around 800 are specialized in physics, chemistry and biochemistry, electronics and information science, nuclear technology, energy utilization and environmental science.

Since the beginning of domestic nuclear activities, research of the institute has also been oriented towards the field of nuclear physics and the use of nuclear energy for peaceful purposes. At the Reactor Centre in Podgorica, four institute research departments and several centres were established.

The Department of Low and Medium Energy Physics performs research on atomic and nuclear physics and is also engaged in radiological environmental protection, namely the regulation of nuclear facilities and the control of the level of radioactive substances in food and the environment. It was for this reason that the Ecological Laboratory, with its mobile unit, was established. The main research areas of the Reactor Physics Department are theoretical, experimental and applied reactor physics, plasma physics, nuclear fragmentation, neutron dosimetry, neutron radiography, the physics of semiconductor devices and oncology. The Reactor Engineering Division performs nuclear engineering and safety research covering the modelling of basic thermohydraulic processes, thermohydraulic safety analyses of the project and severe accidents, structural safety analyses and probabilistic safety analyses. The multidisciplinary research of the Department of Environmental Sciences focuses on the combination of reciprocal physical, chemical and biological processes that influence the environment.

The institute also operates a Nuclear Training Centre on its premises, completed in 1988. It provides training for Krško NPP personnel, organizes radiological protection courses and carries out public information activities. The centre also regularly organizes and hosts training activities and workshops for the IAEA. Their main activity is promotion of knowledge about the use of nuclear energy.

The Reactor Infrastructure Centre is also part of IJS. The main purpose of the centre is operation of a TRIGA Mark II research reactor for the needs of IJS and other research groups. The research reactor was built by IJS in 1966. The reactor was delivered by General Atomics, while the reactor tank and body were built by Slovenian companies. In 1991, it was reconstructed and equipped for pulse operation. Practically all nuclear professionals in Slovenia started their career or attended practical training courses at the TRIGA reactor (including all professors of nuclear engineering and reactor physics at Ljubljana and Maribor universities, as well as directors and key personnel of the Krško NPP, the SNSA and the ARAO). The reactor has accumulated more than 40 years of continuous operation without any failure of major equipment or any event violating safety standards. It is planned that the reactor will operate at least until 2026.

IJS has a long research programme tradition in the field of fission technology. The main efforts are dedicated to reactor physics and reactor technology. Research on reactor physics is directed mostly towards developing new methods for research and power reactor calculations. Work is carried out on neutron, photon and electron Monte Carlo transport, nuclear data evaluation, advanced nodal methods, pin cell and fuel element homogenization and on methods aimed at precise power distribution reconstruction. Also studied are advanced fourth generation reactors, advanced neutron sources and data and materials for fusion technology. The reactor technology research activities belong to the wider field of nuclear engineering and safety. This interdisciplinary research integrates thermohydraulic, structural and probabilistic safety analyses. Advanced reactor technology is also studied, mainly by developing computer models for different physical phenomena. Both reactor physics and technology divisions are strongly involved in research projects within the European Framework Programmes, as well as other programmes.

Slovenia is also very strongly involved in fusion research, mainly for the purposes of the ITER project. Different research departments deal with fusion, and all of them are associated with the Slovenian Fusion Association. The contributions of the institutions in the association to the several areas of the fusion programme are based on R&D experiences of researchers in the fields of nuclear, atomic and plasma physics, ceramic materials development, mechanical engineering and computer aided design. The major equipment available in the institutions includes the following: an ion beam accelerator with materials diagnostic installations; a TRIGA reactor; an advanced fully integrated high resolution microscope facility dedicated to nanostructural materials; and computer systems for simulations, structural mechanical analyses and computer aided design.

Slovenia was admitted to full membership of the IAEA in 1992. Cooperation with the IAEA covers a wide range of activities, including:

1. Cooperation within of international conventions;

2. IAEA missions to Slovenia;

3. Technical cooperation, including attendance of Slovenian experts on IAEA sponsored seminars and training courses, scholarship, scientific visits and research contracts.

Furthermore, Slovenia cooperates with other international organizations, such as the Nuclear Energy Agency of the Organisation for Economic Co-operation and Development (OECD/NEA — observers) and the European Union. Cooperation is also institutionalized through membership in associations, such as the Western European Nuclear Regulators Association (WENRA), the Network of Regulators of Countries with Small Nuclear Programmes (NERS) and the International Nuclear Law Association (INLA).

There is also cooperation through multilateral and bilateral international agreements. The Krško NPP is also a member of WANO.

In 1987, the Slovenian regulatory body was established by the Act on Amendments to the Act on Organization and Competence of the Regulatory Bodies and Republican Organizations and Independent Professional Services of the Slovenian Government.

Over the years, the organizational structure and linkages with other administrative bodies or ministries have changed, becoming more specific in function in recent years.

4.1.1.1. Activity of the Slovenian Nuclear Safety Administration

4.1.1.2. Organization of the Slovenian Nuclear Safety Administration

The licensing process is governed by the provisions of the Ionizing Radiation Protection and Nuclear Safety Act (Off. Gaz. RS, 76/2017 in 26/19).

The licensing system is divided into four steps after the preliminary condition (the planning of the site of nuclear facilities in the national site development plan) is fulfilled:

• Application for the licence for the use of land — the competent body is the Ministry of the Environment and Spatial Planning, with preliminary approval of radiation and nuclear safety — the competent body is the SNSA.

• Application for the licence to construct a facility — the competent body is the Ministry of the Environment and Spatial Planning, with approval from the SNSA.

• Application for the licence for trial operation — the competent body is the SNSA.

• Application for operation and decommissioning — the competent body is the SNSA.

In the Ionizing Radiation Protection and Nuclear Safety Act, there are provisions on:

• Use of land: The planning of the site of nuclear facilities and the conditions for their siting in a spatially and functionally contained area must be carried out with the national site development plan.

• Construction: An investor intending to construct or decommission a nuclear facility must obtain a construction licence for the construction, reconstruction or decommissioning of a nuclear facility. The same applies to the investor intending to carry out construction work in an area of limited use due to the vicinity of a nuclear facility, which affects nuclear safety.

• Trial operation: After construction work is completed, every nuclear facility must first undergo a period of trial operation. It is necessary to obtain approval from the SNSA prior to the commencement of a period of trial operation of a nuclear facility.

• Operation and decommissioning: An investor or operator, who intends to commence or cease operation of a nuclear facility, commence the disposal of spent fuel in a repository of spent fuel or of radioactive waste in a repository of radioactive waste, close a repository of spent fuel or radioactive waste or commence or complete the decommissioning of a nuclear facility, must obtain a licence from the SNSA.

• Periodic safety review (PSR): The act requires that the operator of a nuclear facility ensure regular, full and systematic assessment and examination of radiation or nuclear safety of a facility by a PSR. The PSR must be approved by the SNSA. The approved report on the PSR is the condition for renewing an operating licence.

• Modifications: With regard to every intended modification in the facility or to the management method used or to the operation of the facility, including maintenance work, inspection, testing or the introduction of a technical, organizational or any other type of modification which affects or could indirectly affect the content of the safety analysis report, the operator must evaluate the intended modification in relation to its significance for radiation or nuclear safety. With respect to their significance for radiation or nuclear safety, changes may be:

• Such that it shall be necessary only to notify the SNSA;

• Such that the intention of their implementation must be reported to the SNSA;

• Of such significance for radiation or nuclear safety that for its implementation a licence from the SNSA must be obtained.

The Ionizing Radiation Protection and Nuclear Safety Act contains provisions on issuing, renewal, amendment and expiration of the licence. The act determines the content of a licence, such as details about the operator, a detailed description of the type, scope and purpose of the use of the facility, the duration of the validity of the licence, the operational conditions and limitations relating to the safety analysis report, obligations relating to the periodic safety review, the steps the licensee must take after the licence expires, the financial warranties (if needed), the deadlines and conditions for a repeated review of the evaluation of the radiation protection of exposed workers and the protection and emergency plan, the duration of a licence (a licence may be issued for a maximum of ten years, except in the case of a licence for the completion of decommissioning of a facility or the closure of a facility) and the conditions for the renewal of the licence (the same conditions and procedure as for the issuing of a licence). A licence may be amended at the request of the licensee or ex officio. A licence can be amended ex officio when the conditions related to the nuclear or radiation safety have changed, when required for the protection of the environment or the life or health of the population, for public benefit or when due to external influences or natural phenomena a radiation source is under threat so that nuclear or radiation safety is considerably reduced. The provisions applying to the issue of a licence also apply to the procedure for amending a licence.

The Ionizing Radiation Protection and Nuclear Safety Act has only a few provisions on the licensing procedure, as the General Administrative Procedure Act stipulates all the general principles of the licensing procedure, of which are to be followed also by the SNSA. The rules of the General Administrative Procedure Act must follow all procedural matters, except for cases when the special acts provide for a different solution. For example, based on the provisions of the General Administrative Procedure Act, the licensee can appeal any decision issued by any regulatory body. However, the Ionizing Radiation Protection and Nuclear Safety Act determines the cases, for which no right to appeal against the SNSA’s decision is allowed. In these cases, the licensee will have only the right for judicial review of the decision.

Furthermore, for the implementation of the Ionizing Radiation Protection and Nuclear Safety Act two rules have been issued by the Minister for the Environment which deal in detail with specific licensing aspects.

The Rule on Operational Safety of Radiation and Nuclear Facilities determines:

• The method of using the operating conditions and limits;

• The method and frequency of reporting on the implementation of programmes, on collection and analysis of operating experience;

• The manner and extent of control of ageing;

• The method of maintenance, testing and inspection of structures, systems and components.

The rule also has provisions on:

• The content, scope and frequency of regular and emergency reporting;

• The frequency, content, scope, duration and method of conducting periodic safety reviews and the manner of reporting on these reviews;

• Cases when the SNSA may order a periodic safety review;

• The content, quality and method of probabilistic safety analysis for checking the safety of nuclear facilities and the evaluation methodology and classification of modifications and the manner and form of information and notification of changes in radiation or nuclear facilities.

With respect to potential emergency situations, the rules also detail requirements on an emergency response plan and emergency management of radiation or nuclear facilities, on emergency procedures in radiation or nuclear facilities and on ways of informing about the incident.

The Rule on Radiation and Nuclear Safety Factors determines the conceptual basis for radiation and nuclear facilities, the content of applications and of documents to obtain approvals and licences for nuclear and radiation facilities under the Ionizing Radiation Protection and Nuclear Safety Act. It also determines the contents of safety reports and other documentation necessary to demonstrate and ensure the safety of radiation and nuclear facilities, as well as additional requirements regarding organization of a radiation or nuclear facility and regarding the content and format of the quality assurance programme and its implementation in radiation and nuclear facilities.