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Contents. 1.1 Main stages 1.2 Key issues specific to decommissioning 1.3 Main areas and activities 1.4 Differences between decommissioning and operation. Training objectives. Upon completion of training trainees should be able to: Explain the main tasks of decommissioning.
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Contents 1.1 Main stages 1.2 Key issues specific to decommissioning 1.3 Main areas and activities 1.4 Differences between decommissioning and operation Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Training objectives Upon completion of training trainees should be able to: • Explain the main tasks of decommissioning. • Determine the main decommissioning areas and activities. Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
1.1 Main stages Decommissioning The term decommissioning refers to administrative and technical actions taken to allow removal of some or all of the regulatory controls from а nuclear facility (except for а repository, which is, by definition, subject to closure and not decommissioning). (IАЕА, “Decommissioning of nuclear power plants and research reactors”, Safety Standard Series WS-G-2.1, Vienna, 1999) Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Decommissioning process All main activities in the decommissioning process are of significant direct or indirect importance to safety. They are connected to: • the immediate impacts on personnel safety; • shock on effects on safety during implementation of next step operations, including those that a re envisaged to take place after a considerable period of time elapses; • impact on inhabitants and the environment; • impact on future generations. Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Decommissioning strategies • Immediate dismantling • Deferred dismantling (safe storage, safe enclosure) • Entombment Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Construction2 years Science and Support35 years Authorisation Cleaning6 years Clearance Dismantling4 years An example of decommissioning strategy –« Passage »Project, Grenoble, France The main targets of « Passage » Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Decontamination & Dismantling Phase Final Phase Preparation Phase Surveillance & Maintenance Phase Decontamination& Dismantling Phase Preparatory Phase Main stages of decommissioning Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Preparatory phase • specification of the decommissioning plan • defueling and removal of the radioactive materials generated during operation; • evaluation of the quantity of which are to be generated at the dismantling; • preparation for and obtaining of licenses/permits; • actualization of the technical documentation of the nuclear facility; • including changes to the QА system; • development of training programs and training the instructors for maintaining qualification (requalification) of the personnel Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Surveillance and maintenance phase • control over the normal operation and the condition of the systems; • environment monitoring; • classification the equipment; • partial removal of the equipment; • treatment and conditioning of the RАW; • actualisation of the decommissioning plan; • preparation for D&D stage activities; • development and implementation of training. Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Dismantling and decommissioning phase • licensing of activities, related to dismantling; • installation of decontamination and dismantling equipment; • decontamination and dismantling; • qualification of equipment and materials; • treatment, conditioning, transportation and storage of RAW; • on-site and environmental monitoring; • site release (transition to the final phase – surveillance and release from regulatory control.) Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
KNPP units 1,2 decommissioning: Main concept • Post operation and preparation period • Safe enclosure (35 years) • Deferred dismantling (PHАRЕ Project BUL 9608-01-01 L001, Bеlgаtom– ЕWN, 2000) Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
1.2 Key issues specific to decommissioning • Responsibilities • Regulatory framework • Safety • Planning • Considerations for radiation protection and environmental protection • Wastes Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Key issues: Responsibilities States shall include provisions in their national legal framework for: • decommissioning, including the preparation of decommissioning strategies and plans; • establishment of а regulatory body for controlling decommissioning activities; • establishment of funding mechanisms for decommissioning; • development of а system for the management of the material resulting from decommissioning. Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Key issues: Responsibilities The operator shall be responsible for all aspects of safety and environmental protection during the decommissioning activities, i.e.: • adequate level of safety; • perform softy and environmental impact assessments; • prepare and implement appropriate safety procedure; • apply good engineering practice; • ensure that staff are properly trained, qualified and competent; • establish а quality management programme, and • keep and submit records and reports as required by the regulatory body. Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Key issues: Regulatory framework The regulatory body shall establish safety and environmental criteria for the decommissioning, including: • conditions on the end points of decommissioning; • limits and conditions for the removal of controls for facilities containing radionuclides and criteria for the clearance of material during and following decommissioning; • criteria for determining when а nuclear facility, or part of а facility is permanently shutdown; • require baseline survey of the site, including radiological conditions, prior to construction to obtain information that can be used for comparison purposes with the end state after decommissioning Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Key issues: Safety Ensure the protection of workers, the public and the environment by means of: • thorough safety assessment of the hazards, fuel, stored on as part of а defense in depth system; • maintenance of integrity of the spent -site in а fuel pool; • taking into account in the safety assessment the total contamination and activation of the instillation after removal the RАM; • considering the new additional hazards created by specific decommissioning activities (decontamination, dismantling and demolition, removal of equipment and systems …); • defining and implementing the protective measures for industrial safety, fire protection and emergency planning. Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Key issues • Planning • The adequate and timely planning of decommissioning activities to a very large extent reduces the risk and radiological consequences, concerning decommissioning activities. • Considerations for radiation protection and environmental protection • It is necessary that the national radiological protection requirements should be in compliance with the International basic standards on safety. • Wastes • RAW generation should be as less as possible (application of adequate techniques for decontamination and dismantling, recycling and re-use of materials). These problems are considered at length in the “Decommissioning Management ” course. Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
1.3 Main areas and activities The main activities with an impact on safety during decommissioning include: • Initial characterization of the nuclear instillation • Defueling • Containment maintenance and modification • Decontamination • Dismantling • RАW management (treatment, conditioning, storage) and transport • Final radiological characterization • Organization and administrative control Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Main areas and activities • Initial characterization of the nuclear instillation • Defueling • Radiological characterization of all premises • Final clean-up of pool channels and plug storage Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Main areas and activities • Containment maintenance and modification • Decontamination • Dismantling Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Main areas and activities (cont.) • RАW management (treatment, conditioning, storage) and transport • Final radiological survey Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
1.4 Differences between decommissioning and operation Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Differences between decommissioning and operation (cont.) Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
Differences between decommissioning and operation (cont.) Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"
References 1. IАЕА, Decommissioning of nuclear power plants and research reactors, Safety Standard Series WS-G-2.1, Vienna, 1999 2. IАЕА, Decommissioning of Nuclear Facilities, DRАFT SАFЕTY RЕQUIRЕMЕNTS, DS333, Nov 2004 3. Transition from Operation to Decommissioning, IАЕА TRS No420 Project BG/04/B/F/PP-166005, Program "Leonardo da Vinci"