It is necessary for the safe decommissioning and environmental remediation in decommissioning of reactor facilities damaged by severe accidents to define policy setting and improvement legal system. Because there are only two regulations about decommissioning program and decommissioning funding and anyway these contents are insufficient in existing law of Korea. For resolving suspicions and relieving uneasiness of the public about a nuclear power plant, it is necessary condition to construct a system of safe decommissioning and environmental remediation in accordance with global standards.
IAEA published the Policy and Strategy Guide NW-G-2.1 ‘Policies and Strategies for the Decommissioning of Nuclear and Radiological Facilities’ and the Safety Requirement WS-R-5 ‘Decommissioning of Facilities Using Radioactive Material’ as documents on safe decommissioning. IAEA published the Safety Requirement WS-R-3 ‘Remediation of Areas Contaminated by Past Activities and Accidents’ and the Safety Guide WS-G-3.1 ‘Remediation Process for Areas Affected by Past Activities and Accidents’ as documents on environmental remediation.
From the documents of IAEA serious implications for constructing a system of safe decommissioning and environmental remediation can be deduced. Considerations are classified into the before transfer, preparation, and implementation phases of the decommissioning. During the before transfer phase, it is important to ensure that fuel debris has been removed, and that the capability to confine radioactive materials is secured. And the characteristics of fuel debris should be understood before it is removed, treated and disposed of.
During the preparation phase the licensee should establish the decommissioning strategies that take account of all related factors including a potential disposal of special radioactive waste with unidentified properties such as fuel debris generated due to a severe accident. The licensee should determine a decommissioning end state and review in accordance with the decommissioning phases. Besides, in order to determine a end state the national government and licensee should continue close discussions with the stakeholders. The licensee should develop a decommissioning program based on the decommissioning strategies as soon as possible and a comprehensive radioactive waste management program that defines an appropriate end point(final destination of waste) and long-term safety actions. The licensee should estimate specific and detailed decommissioning costs, taking account of the characteristic of the affected reactor. The licensee should arrange the monitoring activities to maintain the facility in safe condition. And the national government or regulatory body should determine the clear and transparent rules for the public involvement in the decision making process as regards the important issues.
During the implementation phase the licensee should investigate the contamination conditions of rubbles etc. on the site in accordance with the radioactive waste management program and review the program to reflect the actual contamination condition and enter the investigation result into the radioactive waste database. In view of reducing exposure dose systematically and in phase the licensee should review the decontamination criteria (dose criteria) for each area in site according to the decommissioning implementation.
Futhermore, based on the document of IAEA’s environmental remediation, the following regard to the environmental remediation of the areas affected by the severe accident should be organized: establishment of legal framework, definition of roles and responsibilities, selection of remediation criteria and site characteristics investigation, optimization of remediation measures and development of remediation plan, management during remediation, and management after remediation.
For improvements related the framework for the decommissioning regulation it is necessary to study decommissioning-related regulatory requirements at each stage of the process from facility design to license termination and to review the current system for consistent and continued decommissioning regulations. Regulation schemes commensurate with the radiation risk of decommissioning activities and embodiment of graded approach in the decommissioning regulations are also important. An integrated decommissioning management system and safety culture should be improved.