The Council of State, on the submission of the Ministry of Trade and Industry and by virtue of Section 81, first paragraph, point 1 of the Nuclear Energy Act (990/1987) given on 11 December 1987, has decided on the following:
Chapter 1
Scope and definitions
Section 1
Scope
This Decision shall apply to permanent disposal of spent nuclear fuel into bedrock. The provisions of this Decision shall also apply to other nuclear waste that is disposed of in the same emplacement rooms as spent nuclear fuel.
The provisions of the Transport of Dangerous Goods Act (719/1994) and of the Nuclear Energy Act (990/1987) shall apply to the transport of spent nuclear fuel to a disposal facility.
Section 2
Definitions
For the purposes of this Decision:
- ‘disposal’ shall mean permanent emplacement of nuclear waste into bedrock;
- ‘a disposal facility’ shall mean the entity of installations, intended for disposal, which includes:
- a facility for the encapsulation of spent fuel bundles; and
- an ‘underground facility’, consisting of rooms in the bedrock (‘emplacement rooms’) for the depositing of the spent fuel bundles conditioned for disposal (waste canisters), and the auxiliary rooms connected to them;
- ‘operation of the disposal facility’ shall mean actions taken at the disposal facility during its operational period; the operational period commences when the disposal facility has obtained the licence to receive nuclear waste and terminates when the Radiation and Nuclear Safety Authority has confirmed the nuclear waste to have been permanently disposed of in a manner approved by it;
- ‘disposal site’ shall mean the location of the disposal facility including the protection zones, if any, and, after the operational period, the site entered into the land register in accordance with Section 85 of the Nuclear Energy Decree, including the soil and bedrock underneath that site;
- ‘annual effective dose’ shall mean an effective dose that arises from external radiation and intake of radioactive substances during a period of one year; an effective dose shall mean the weighted sum of the equivalent doses of tissues and organs subjected to radiation, where the equivalent dose shall denote the product of the mean energy absorbed per unit mass in tissue or organ and of the radiation weighting factor;
- ‘long-term safety’ shall mean the safety of disposal after the operational period of the disposal facility, taking account of radiation impacts on man and the environment;
- ‘assessment periods’ are time periods of varying length, used in the evaluation of long-term safety;
- ‘barrier’ shall mean the host rock and a technical structure or material surrounding the disposed radioactive substances, as well as a physico-chemical interaction which hinders or slows down the release and migration of the disposed radioactive substances;
- ‘anticipated operational transient’ shall mean a safety-related incident during the operational period of the disposal facility with estimated average occurrence of less than once a year but having a significant probability to occur at least once during the operational period of the facility;
- ‘postulated accident’ shall mean a safety-related incident during the operational period of the disposal facility with low probability to occur during that period;
- ‘expected evolution’ shall mean such changes affecting the performance of barriers that have a significant probability to occur during the assessment period; these changes may be due to physico-chemical processes in the emplacement rooms, geological or climatic phenomena or human actions;
- ‘unlikely disruptive events impairing long-term safety’ shall mean such potential events affecting substantially the performance of barriers that have a low probability to occur during the assessment period; these events may be due to geological phenomena or human actions;
- ‘quality assurance’ shall mean all systematic and planned actions necessary to ensure that a component, facility or activity will fulfil specified requirements;
- ‘safety culture’ shall mean such attitude, line of action and working atmosphere in the organisation in question that emphasises consideration of factors relevant to the operational and long-term safety in the various phases of implementation of disposal.
Chapter 2
Radiation protection objectives for the planning and implementation of disposal
Section 3
Application of the Radiation Act
Besides the Nuclear Energy Act and the provisions and regulations pursuant to it, the provisions of Section 2 (General principles) and Chapter 9 (Radiation work) of the Radiation Act shall apply to the planning and implementation of disposal.
Section 4
Operation of disposal facility
The operation of a disposal facility shall not cause radiation exposure that could endanger occupational or public safety or could otherwise harm the environment or property.
The disposal facility and its operation shall be designed so that:
- as a consequence of undisturbed operation of the facility, discharges of radioactive substances to the environment remain insignificantly low;
- the annual effective dose to the most exposed members of the public as a consequence of anticipated operational transients remains below 0.1 mSv; and
- the annual effective dose to the most exposed members of the public as a consequence of postulated accidents remains below 1 mSv.
In the application of this Section, such radiation doses that arise from natural radioactive substances, released from the host rock or groundwater bodies of the disposal facility shall not be considered.
Section 5
Long-term safety
In any assessment period, disposal shall not cause health or environmental effects that would exceed the maximum level considered acceptable during the implementation of disposal.
Disposal shall be so designed that as a consequence of expected evolutions, the radiation impacts remain below the constraints given in paragraphs 3 and 4.
In an assessment period that is adequately predictable with respect to assessments of human exposure but that shall be extended to at least several thousands of years:
- the annual effective dose to the most exposed members of the public shall remain below 0.1 mSv; and
- the average annual effective doses to other members of the public shall remain insignificantly low.
Beyond the assessment period referred to above, the average quantities of radioactive substances over long time periods, released from the disposed waste and migrated to the environment, shall remain below the nuclide specific constraints defined by the Radiation and Nuclear Safety Authority. These constraints shall be defined so that:
- at their maximum, the radiation impacts arising from disposal can be comparable to those arising from natural radioactive substances; and
- on a large scale, the radiation impacts remain insignificantly low.
Section 6
Consideration of unexpected events
The importance to long-term safety of unlikely disruptive events impairing long-term safety shall be assessed and, whenever practicable, the acceptability of the consequences and expectancies of radiation impacts caused by such events shall be evaluated in relation to the dose and release rate constraints specified in Section 5 above.
Chapter 3
Planning for long-term safety
Section 7
Method of implementation and timing of disposal
The implementation of disposal, as a whole, shall be planned with due regard to safety. The planning shall take account of the decrease of the activity of spent fuel by interim storage and the utilisation of best available technology and scientific knowledge. However, the implementation of disposal shall not be unnecessarily delayed.
Disposal shall be planned so that no monitoring of the disposal site is required for ensuring long-term safety and so that retrievability of the waste canisters is maintained to provide for such development of technology that makes it a preferred option.
Section 8
Barriers
The long-term safety of disposal shall be based on redundant barriers so that deficiency in one of the barriers or a predictable geological change does not jeopardise the long-term safety. The barriers shall effectively hinder the release of disposed radioactive substances into the host rock for several thousands of years.
Section 9
Disposal site
The geological characteristics of the disposal site shall, as a whole, be favourable for the isolation of the disposed radioactive substances from the environment. An area having a feature that is substantially adverse to long-term safety shall not be selected as the disposal site.
Section 10
Disposal depth
The repository shall be located at a sufficient depth in order to mitigate the impacts of above-ground events, actions and environmental changes on the long-term safety and to render inadvertent human intrusion to the repository very difficult.
Chapter 4
The disposal facility and its operation
Section 11
General safety principles
To ensure the operational safety of the disposal facility and the long-term safety,
- proven or otherwise carefully examined and high-quality technology shall be employed;
- advanced quality assurance programmes shall be obeyed; and
- advanced safety culture shall be maintained in the design, construction, operation and closure of the disposal facility.
Section 12
Continuous safety improvement
Operating experience from the disposal facility shall be systematically followed and assessed. For further safety enhancement, such actions shall be taken that can be regarded as justified considering operating experiences and the results of safety research as well as the progress in science and technology.
Section 13
Safety classification
The systems, structures and components of the disposal facility shall be classified on the basis of their importance to the operational safety and to the long-term safety of the disposal facility. Their quality level and the inspections and tests required to ascertain and verify the quality level shall be adequate considering the importance to safety of the item concerned.
Section 14
Ensuring of safety functions
The functions at the disposal facility that are important to the maintenance of the integrity of fuel bundles and waste canisters, prevention of radioactive releases and to the radiation protection of the personnel shall be ensured.
Section 15
Operational conditions, specifications and condition-monitoring
Technical and administrative requirements and restrictions for ensuring the operational and long-term safety shall be set forth in the technical safety specifications of the disposal facility. Appropriate instructions shall exist for the operation, maintenance, regular in-service inspections and periodic tests as well as for transient and accident conditions. The reliable function of systems and components shall be ensured by adequate maintenance and by regular in-service inspections and periodic tests.
Section 16
Personnel
The personnel at the disposal facility shall be suitable for their duties, qualified and well trained. The competence of the personnel shall be maintained and enhanced through training programmes.
Section 17
Limitation of radioactive discharges
The dispersion of radioactive substances inside the disposal facility as a consequence of handling of spent fuel shall be limited to the minimum. The released solid, liquid and particulate airborne radioactive matter shall be collected and treated as radioactive waste.
Section 18
Radiation monitoring
Compliance with operational radiation protection constraints shall be ensured by means of continuous or regular monitoring, focused on the potential discharge routes at the disposal facility and on the activity concentrations in the surroundings of the disposal facility.
Section 19
Prevention of criticality accident
The formation of such spent fuel configurations that would cause an uncontrolled chain reaction of fission shall be prevented by means of structural design of systems and components.
Section 20
Prevention of fire and explosion hazards
The disposal facility shall be designed so that the likelihood of a fire is low and its consequences are of minor importance to safety.
The disposal facility shall be designed so that explosions that would jeopardise the integrity of spent fuel bundles, waste canisters, or the components or chambers containing radioactive substances, are reliably prevented.
Section 21
Consideration of external events
The disposal facility shall be designed so that the impacts caused by potential natural phenomena and other external events are taken into account.
Section 22
Physical protection and emergency preparedness
The Decision of the Council of State on the general regulations for physical protection of nuclear power plants (396/1991) shall apply, in accordance with its Section 12, to the disposal facility to the extent required by the degree of threat posed by unlawful activities to the nuclear facility concerned.
The Decision of the Council of State on the general regulations for emergency response arrangements at nuclear power plants (397/1991) shall apply, in accordance with its Section 10, to the disposal facility to the extent required by the degree of danger posed by the nuclear facility concerned.
Section 23
Control of nuclear materials
The design, construction, operation and closure of a disposal facility shall be implemented so that control of nuclear materials can be arranged in accordance with pertinent regulations.
Chapter 5
Specific requirements for the underground facility
Section 24
Design of the emplacement rooms
At the planned disposal depth, blocks of bedrock with adequate size and intactness shall exist for the construction of the emplacement rooms. For the design of the emplacement rooms and for the acquisition of data needed for the safety analysis, the host rock shall be adequately characterised by means of investigations performed at the planned disposal depth.
Section 25
Preservation of the integrity of host rock
The design, excavation, other construction and closure of the underground facility shall be implemented in the best manner with regard to retaining the characteristics of the host rock that are important to long-term safety.
Section 26
Prevention of damages of waste canisters
Excavation works related to enlargement of the underground facility shall not be performed in the vicinity of disposed waste canisters and even otherwise the operations in the underground facility shall be designed with regard to efficiently prevent damages to waste canisters. Regarding underground excavation and construction works, transfers of rock masses or other comparable extensive transfers shall not be performed in the same areas which might simultaneously be used as transport routes for waste packages.
Chapter 6
Demonstration of compliance with safety requirements
Section 27
Operational safety of the disposal facility
If compliance with the requirements for the operational safety of the disposal facility cannot be directly ascertained, it shall be demonstrated by experimental or computational methods or their combination. The computational methods shall be selected so that the detriment or risk likely to occur, with high degree of certainty, remains below the results of analyses. The applied computational methods shall be reliable and well validated for dealing with the events of interest.
Section 28
Demonstration of long-term safety
Compliance with long-term radiation protection objectives as well as the suitability of the disposal concept and site shall be justified by means of a safety analysis that addresses both the expected evolutions and unlikely disruptive events impairing long-term safety. The safety analysis shall consist of a numerical analysis based on experimental studies and be complemented by qualitative expert judgement whenever quantitative analyses are not feasible or are too uncertain.
Compliance with the radiation protection constraint given in Section 5 shall be demonstrated by assuming such a self-sustaining community in the vicinity of the disposal site that receives the highest radiation exposure. In addition to the impacts on man, potential impacts on species of fauna and flora shall also be examined.
Section 29
Uncertainties related to long-term safety
The data and models introduced in the safety analysis shall be based on the best available experimental data and expert judgement. The data and models shall be selected on the basis of conditions that may exist at the disposal site during the assessment period and, taking account of the available investigation methods, they shall be site-specific and mutually consistent. The computational methods shall be selected on the basis that the results of safety analysis, with high degree of certainty, overestimate the radiation exposure or radioactive release likely to occur. The uncertainties involved with safety analysis and their importance to safety shall be assessed separately.
Chapter 7
Miscellaneous provisions
Section 30
Detailed regulations
The Radiation and Nuclear Safety Authority shall issue detailed regulations relating to the safety of disposal of spent nuclear fuel.
Section 31
Entry into force
This decision enters into force on 1 May 1999.