Experts: T. Boal and S. Suksi

10.1. REGULATORY FRAMEWORK

The legislative framework for radiation protection in Slovenia is provided for in the 1984 Act, which was proclaimed by the Federal Republic of Yugoslavia, and in the 1980 Act, which was proclaimed by the Republic of Slovenia. There are eleven regulations covering radiation protection and safety: Ten regulations cover radiation in the workplace, environment and in medical practices (Z1 – Z10) and one regulation covers radionuclides in agriculture (K1).

The current legislation defines the sources of ionizing radiation that are covered by the Act. There is no definition of exposure situations that are excluded from meeting the requirements of the legislation. Exemption levels are defined in Regulation Z4, where radioactive materials are defined to be those materials with a specific and total activity above prescribed levels. There are prescribed levels for four groups of radionuclides, based on the radiotoxicity of each group of radionuclide. Apart from the mining of prescribed substances, natural sources of radiation are not covered by the legislation. However, the Ministry of Health has used the general powers in the Health Act to protect the health of the community to carry out surveys of radon levels in homes, in kindergartens, and in schools in co-operation with the SNSA.

Paragraph 3 of Article 4 of the government decree on Methods, Subject and Conditions of Dealing with Public Services of Radioactive Waste Management issued in May 1999, covers abandoned radiation sources. This decree states that the ARAO is responsible for the collection, clean-up and storage of radioactive waste in the case, when the generator of the radioactive waste cannot be identified.

The regulatory authorities are in the process of drafting new legislation to make the radiation protection legislation in Slovenia consistent with the latest international standards. For example, Regulation Z6 establishes a limit for effective dose of 50 mSv per year for occupationally exposed individuals, while the ICRP (ICRP60 - 1990) and the IAEA Safety Series No.115 - International Basic Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources recommend a limit for effective dose of 20 mSv per year.

10.2. REGULATORY CONTROL

The 1994 Act sets out the competences of different government bodies. The scope of the competence of the SNSA is defined as follows: “The Slovenian Nuclear Safety Administration performs administrative and technical tasks related to nuclear and radiation safety of nuclear facilities; to trade transport and handling of nuclear and radioactive materials; to safeguards and inventory of radioactive materials; to physical protection of nuclear materials and nuclear facilities; to liability for nuclear damage; to professional qualifications of operators of nuclear facilities and their training, to quality assurance in this field; to provision of radiation monitoring; to provision of radiation early warning system in case of nuclear or radiation accidents; to international co-operation in the field of administration and to other tasks specified by regulations; supervision of laws and other rules and regulations governing the domain of nuclear safety”.

The scope of the competence of the Ministry of Health covers health matters in many areas; e.g., foodstuffs, medicines. The scope includes the following: “… the implementation of health control over living and working environment …… over immission values of ground and water quality;…..sources of ionizing and non-ionizing radiation, …". Immission is defined in Regulation Z2 (Sections 2 and 3) as individual specific activities (Bq.kg^-1, Bq.m^-3, etc.) of all important radionuclides and all important pathways in specified environments on certain locations in the surroundings of nuclear facilities, that were caused by emission.

Therefore there is an overlap in the responsibilities of the two authorities. There are some areas of the legislation where both authorities carry out inspections and receive reports from licensed users of radiation sources.

Both regulatory authorities are in the process of developing new legislation to bring the Slovenian legislation into line with the latest international radiation protection and safety practices. However, the two authorities are working independently in developing the new legislation.

10.3. OPTIMIZATION PRINCIPLE

The Optimization Principle for ALARA (as low as reasonably achievable) practices is set out in Articles 5 and 7 of Regulation Z6.

The internal ALARA management plan for the Krš ko (KNPP) nuclear power plant requires that an optimization review be carried out for activities that will result in a collective dose of more than 10 man.mSv. There are about 5 activities each year that require an ALARA optimization review. With respect to the replacement of the generators at the KNPP in April 2000, an ALARA management plan has been developed and approved by the SNSA and the Ministry of Health.

The SNSA carries out inspections of the KNPP prior to an outage and requests information on whether there are any ALARA management plans for the next outage. The SNSA does not approve the ALARA management plans, but asks how the plan was developed and if the estimated doses are based on previous experience. The SNSA and the Ministry of Health have not developed regulatory guides to provide advice on how the nuclear power plant operator should develop the ALARA management plan. In addition, the Ministry of Health has not developed regulatory guides in relation to ALARA optimization for radiation sources in industrial and medical applications.

1. BASIS - IAEA Safety Fundamentals - Radiation Protection and the Safety of Radiation Sources, paragraph 4.9 (SS-120), states: “In relation to exposures from any particular source within a practice, except for medical exposures in radiodiagnosis and radiotherapy, protection and safety shall be optimized in order that the magnitude of individual doses, the number of people exposed and the likelihood of incurring exposures all be kept as low as reasonably achievable, economic and social factors being taken into account, with the restriction that the doses delivered to individuals by the source be subject to dose constraints.”

10.4. INVENTORY OF SOURCES

The Ministry of Health maintains an inventory of all radiation sources in Slovenia. The inventory is updated as new radiation sources are licensed. An inspection of each radiation source is required before the radiation source is licensed and each subsequent year. These inspections are carried out by an authorized organization. Usually the authorized organization uses an inspection checklist approved by the Ministry for Health. The inspection report of the radiation source prior to the initial authorization is submitted with the application for authorization.

The inventory includes the date of the last inspection and authorized organization survey. The owners of radiation sources that have not been inspected in the previous 12 months are contacted by the Ministry of Health.

10.5. ENVIRONMENTAL PROTECTION

Regulation Z2 sets out the requirements for regular radiation monitoring of the environment in the vicinity of nuclear installations, and a dose assessment of critical groups. The environmental surveillance includes regular sampling of water, sediment, soil, milk, food chain, drinking water, and dose rate around the plants.

With respect to the environmental radiation monitoring programme in the vicinity of the KNPP, KNPP discusses with the SNSA each year the content of the radiation monitoring programme. The operators of the nuclear power plant negotiate contracts with authorized organizations to carry out the monitoring programme and to prepare of the environment report each year. In practice, the radiation monitoring has been carried out by four organizations (two of these organizations are based in Slovenia and the other two are based in Croatia). One of the organizations co-ordinates the analysis of monitoring results, carries out the dose assessment and prepares a report for submission to the regulatory authorities.

The contract between the operators of the nuclear power plant and the authorized organizations requires that authorized organizations adopt a quality assurance programme. This quality assurance programme requires that analysis of standard samples are carried out in the laboratories, and that the same samples are analysed in more than one laboratory.

An annual dose constraint of 0.05 mSv has been applied to effluent releases from the KNPP since the original permit was issued in 1974. A dose constraint of 0.2 mSv for external radiation and from radioactive waste was applied in the licence issued for temporary storage facility for radioactive waste at KNPP. The maximum dose to the critical group in the vicinity of Krš ko in 1997 was estimated to be 0.008 mSv.

The SNSA and Ministry of Health are also involved in carrying out investigations into radon in homes and in schools and in kindergartens. An intervention level of 400 Bq.m^-3 has been applied.

10.6. DOSIMETRY SERVICES

There are two authorized providers of external personal dosimetry services in Slovenia: the Institute of Occupational Health (IOH) and the Jozef Stefan Institute (JSI). However, neither regulatory authority accredits the dosimetry services. The JSI holds the secondary standard for the measurement of ionizing radiation. The IOH carry out periodic checks of their external personal systems against the secondary standard.

The Zirovski vrh Mine (RZM) provides an internal dosimetry service for radon exposure of workers in the uranium mine and other underground mines, and the JSI provides an internal dosimetry service for the Cave of Postojna (a tourist underground cave system). Thyroid doses to some medical staff handling I-131 have been assessed: however, occupational doses from I-131 are not included in the national dose register.

The SNSA commenced the development of a database on occupational doses to ionizing radiation in nuclear facilities in December 1998. The Health Inspectorate commenced the development of a national database on occupational doses to ionizing radiation in April 1999.

10.7. AUTHORIZED ORGANIZATIONS

The regulatory authorities both rely on authorized organizations to carry out a number of activities including: to provide personal dosimetry services; to provide training courses in radiation protection and safety; and to inspect radiation sources.

Some of the authorized organizations were set up in the early 1980s by government decree. The regulatory authorities have not reviewed in the past the activities of the authorized organizations in the areas of radiation protection.

10.8. MEDICAL EXPOSURES

Sources of ionizing radiation used for medical purposes are regulated by the Ministry of Health. The Ministry of Health has an inventory of sealed radiation sources, X-ray machines and centres using radioisotopes for nuclear medicine. These sources are inspected by an authorized organization prior their use being authorized by the Ministry of Health. At present, there is no regular determination of patient dose for diagnostic procedures.

The total exposure of the population of Slovenia from various sources of ionizing radiation is summarized in the 1997 Annual Report of the SNSA. The following estimates are made:

Environmental sources – natural radiation sources 2.5 mSv

Man-made sources: Medical procedures 1.5 mSv

Chernobyl 0.06 mSv

Krš ko NPP (critical group) 0.008 mSv

Total – man-made 1.6 mSv

TOTAL EXPOSURE OF POPULATION 4.1 mSv

The 1997 Annual Report states that the estimate of the exposure of the Slovenian population due to medical sources is very approximate, and is based on an extrapolation of German data to the Slovenian situation. The doses are assumed to be an average across the Slovenian population, and the radiation dose from Krš ko applies to the critical group in the vicinity of Krš ko. Nevertheless, medical exposures to ionizing radiation is by far the largest source of man-made exposure of the Slovenian population. The International Commission of Radiological Protection noted in 1990 (ICRP60) that there was a considerable range of patient doses from one medical practice to another for the same procedure, and that patient doses could be reduced with simple, low cost measures without loss of diagnostic information, but the extent to which these measures are used varies widely.

10.9. EMERGENCY PREPAREDNESS

A network of radiation monitoring systems to detect accidents at nuclear power plants is maintained by the SNSA, KNPP and other organizations in Slovenia. This network includes monitoring of external gamma radiation at 38 locations (there is real time data retrieval) throughout Slovenia. Data from this network is forwarded to the European system EURDEP every week, at Ispra in Italy. Aerosol levels are measured at two locations in Slovenia (one of these sites is inside the boundary fence of the Krš ko NPP). A third aerosol monitoring system, to be located about 2 km downwind (prevailing wind) from the nuclear power plant site, commences operation in December 1999.

In the event of an accident at a nuclear installation, the Division of Radiation Protection at the SNSA provides a technical support group for dose assessment. As the SNSA does not have the number of required staff in this area, staff from authorized organizations assist in this task.

In the event of an accident or incident involving radiation sources, for example, an incident involving an industrial radiography source, or a traffic accident involving the transport of radioactive materials, the Jozef Stefan Institute attends such accidents or incidents in a mobile monitoring vehicle provided by the Ministry of Defence. However, there is not a national emergency plan to respond to radiation emergencies.

10.10. RADIATION PROTECTION RESOURCES

The State Office for European Affairs in Slovenia has been estimated that an additional 15 staff in the radiation protection area of the SNSA, Ministry of Health and authorized organizations will be required in Slovenia to meet the requirements of European Commission.

Both Ministry of Health and the SNSA have a large percentage of inexperienced staff in the areas of radiation protection. There has been a high turnover of junior staff in the radiation protection at the SNSA in recent years. There are four physicists in the radiation protection section of the SNSA: two of these physicists have considerable experience in radiation protection and most of the remaining staff have joined the SNSA in the past two years. There are three physicists in the Ministry of Health, who have been with the Ministry for four years, two years and three months, respectively, as of the review in December 1999.

There is no mechanism for the regulatory authorities to require that the staff of the authorized organizations meet specified educational qualifications and undertake specified training before they carry out radiation safety activities.

The IAEA Basic Safety Standards No.115 - International Basic Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources, and the European Commission Basic Safety Standards both refer to qualified experts. Using the criteria in the BSS, there are no qualified experts in Slovenia and there is no training programme in Slovenia to accredit qualified experts.

See recommendation in Section 1.5.1. (a) of this report.