1. REACTOR DECOMMISSIONING Michele Laraia, IAEA World Outlook in Nuclear Technology, March 27-29, 2008, Istanbul, Turkey

2. Contents • International Context • IAEA safety and industrial guidance • Technological issues • Financial issues • Organizational and management issues • Feedback from decommissioning experience to design and construction of new nuclear power plants

3. Decommissioning – a safety-oriented IAEA definition The administrative and technical actions taken to allow the removal of some or all of the regulatory controls from a nuclear facility (except for a repository or for certain nuclear facilities used for the disposal of residues from the mining and processing of radioactive material, which are ‘closed’ and not ‘decommissioned’).

4. A broader vision of decommissioning • The two main objectives of decommissioning are to render the site permanently safe and to recover it, as far as practicable, for reuse (TRS # 444, WNA 2006)

5. Status of the Decommissioning of Nuclear Facilities around the World* • Nuclear Power Plants • Operating: 446 • Under construction: 45 • Shutdown, under decommissioning: 107 • Decommissioned: 14 • Research reactors and critical assemblies • Operating: 288 • Under construction: 9 • Shutdown, under decommissioning: 119 • Decommissioned: 404 * various IAEA sources, 2004-2005

6. Status of the Decommissioning of Nuclear Facilities around the World* • Fuel cycle facilities (uranium milling, uranium conversion/recovery, uranium enrichment, fuel fabrication/heavy water production, fuel reprocessing) • Operating: 423 • Under construction: 19 • Shutdown, under decommissioning: 297 • Decommissioned: 192 • Medical, research and industrial facilities: ~ 320 000 • Cold war legacy • Total decommissioning liability for the period up to 2050 of about $ 1000 billion ($ 1 trillion) !!! *various IAEA sources 2004-2005 • * various IAEA sources, around 2004

7. Background • IAEA Statute: • Develop safety standards • Promote activities cost-effectively and consistent with Safety Standards Nuclear Safety Radiation Safety Waste Safety Transport Safety Peer reviews Technical cooperation Training Exchange/disseminate information (technical reports/docs) Research and development

8. DECOMMISSIONING

9. The Decommissioning Programme of the IAEA: Safety-related Aspects

10. Safety Standards Hierarchy Safety Fundamentals Safety Requirements Safety Guides Safety Reports

11. Safety Requirements (selection) • The preferred decommissioning strategy shall be immediate dismantling. The decision to undertake the deferred dismantling or entombment options shall be justified on a facility-by-facility basis.

12. Safety Requirements (cont‘d) • States shall include provisions in their national legal framework for establishment of funding mechanisms for decommissioning

13. Safety Requirements • A decommissioning plan shall be developed since the design and construction stage and submitted by the operator as part of the application for an authorization to operate the facility • and regularly reviewed to reflect changes in: • operation • regulatory requirements • technological improvements, etc. • It shall demonstrate: • that the selected decommissioning option is safe • no undue burdens to future generations • dismantling and decontamination techniques minimising waste generation and airborne contamination

14. The Decommissioning Programme of the IAEA: Strategic and Technological Aspects

16. Explosive dismantling of a stack

17. Brookhaven Reactor Decommissioning : Work Begins in South Duct 12/27/03 (underground)

18. Building wall clearance through ISOCS (Vandellos NPP, Spain)

19. CLOSING THE NUCLEAR LOOP REDEVELOPMENT! CONSTRUCTION A PB w Q S F SITING PHPP OPERATION F AND NOW ? DECOMMISSIONING E M

20. The “Vaporsphere” at ANL, USA, a former nuclear facility, now a warehouse

21. Journalists watching decommissioning activities at Vandellos NPP, Spain

22. Handheld mechanical cutting equipmentfor small contaminated pipes (decommissioning with limited resources)

23. IAEA’s Technical Assistance Projects on Decommissioning (selection)

24. SLOVAKIA (2000, ongoing) Robotic, Remote Viewing Technologies for D&D of A-1 NPP (e.g. IGRIP, laser scanner, gamma camera).

25. A1 NPP Slovakia, Aladin gamma camera

26. A1 Slovakia Graphic simulation (IGRIP)

28. LITHUANIA ( 2000, ongoing) Planning for Decommissioning of Ignalina NPP (e.g. upgrading of national infrastructure, review of draft docs., workshops)

29. Technology Issues

30. Introduction: Decommissioning can and has been done • Total dismantling of prototype facilities and commercial NPPs has been done up to “green field”, like: • KKN, Shippingport NPP, JPDR • Maine Yankee, Trojan • More NPP are currently being decommissioned (Stade, Wuergassen etc) • From 1990 until 2000 the technology has been improved and the major basis have been set up • The D&D “market” is now growing rapidly, expected to peak around 2015-2020

31. A view of some of the pilot projects Development of the technology (a piece of history) AT-1 KRB-A WAGR EWN BR3-PWR

32. Development of the technology (a piece of history) • Today, the US has carried out many times the one piece removal of RPV...

33. Is technology mature? • Current technology is able to carry out most decommissioning activities and operations • Nevertheless, improvements can be done for improving the operations • The incentives to improve technology are rather important: • reduce the costs • limit the waste production • reduce operator exposure • reduce contamination hazard • improve the industrial safety • reduce the industrial and financial risk • be able to react to unforeseen situations

34. Some overview of the available technology • Let us separate it in three main categories: • characterization techniques • before dismantling • during dismantling • after dismantling • decontamination techniques • for metal • for concrete • dismantling techniques • for activated metal • for contaminated metal • for concrete

35. Characterization before dismantling : a difficult job but a lot of possibilities • Before dismantling: • by direct measurement on site • by sampling & measurement (lab or radiochemistry) • by remote monitoring (e.g. ISOCS) • by calculation (improvements in activation codes and even contamination models)

36. Characterization & measurement during D&D: a hard job • Some measurements have to be carried out during the dismantling to allow sorting the material or defining the route to follow

37. Characterization after decommissioning: an important step • For radwaste management or material free release, the needs for characterization are important! • Gross gamma counting • Gamma spectrometry • Alpha spectrometry • Use of isotopicvector • ....

38. Decontamination: this concept covers a very broad spectrum of activities • Metal decontamination: • before dismantling • after dismantling • Concrete decontamination • Site or soil decontamination

39. Example of application of thorough chemical decontamination: the Medoc workshop at BR3

40. Material after decontamination

41. Another example: Projection of CO2 ice or water ice • CO2 ice pellets are projected at high speed against the surface • The CO2 pellets evaporate and remove the contamination • The operator works in ventilated suit inside a ventilated room to remove CO2 and contamination • Needs some decontamination tests before selecting the process (not efficient for deep contamination)

42. New techniques are currently developed to improve the efficiency and reduce the effluents • Methods based on laser ablation • Increasing the pressure of the water jetting • New chemical or electrochemical methods; new effluents treatment methods • Other methods... • But they are still under development!

43. Examples of Hand scabbling(labour intensive) Courtesy from Belgoprocess

44. Automatic wall shaver Close up view of the machine Use on a reprocessing cell wall Courtesy from Belgoprocess

45. Remote controlled jackhammer Courtesy from Belgoprocess

46. Some other shots... Diamond centerless saw Brokk and jackhammer Shaver

47. Some views of the very large number of processes Explosive Cutting Pipe cutter Laser Cutting Plasma Cutting

48. The cut pieces must match the material handling and removal requirements Output dismantling = Input material management e.g. Belgian standard : 400-l drum

49. Secondary waste generated • The secondary waste generated depends on the piece being cut and the cutting techniques as well • The final volume of the secondary waste is the main determining economical factor • Size and size distribution are from first importance in order to allow collection of the generated secondary waste. Eventually, different physical forms of waste can be generated (solid and gaseous…)

50. Conventional safety aspect • Dismantling techniques are close linked with the following hazards: • Heat generation (plasma torch) • Piece falling down • Sharp edges • Projection of material • Working at heights • Noise • Working in a continually different environment • …