1 Successful decommissioning of a nuclear plant Evelyn Hooft Bart Thieren 20 june 2008

2 Introduction ■ NIRAS: public institute responsible for the safe management of radioactive waste in Belgium. Has developped a coherent and central management system ■ Belgoprocess: industrial daughter of NIRAS, main activities are treatment and storage of radioactive waste and decommissioning of shut down nuclear installations

3 Introduction ■ NIRAS is charged by the belgian State with the clean up of nuclear liabilities = task of public benefit ~ 1986 : site BP 1 (Eurochemic) ~ 1989 : site BP 2 (Ex waste department of SCK.CEN) ~ 1991 : installations and fission products originated from research reactors and other installations of the SCK.CEN

4 Foto site 1

5 Eurochemic

6 Eurochemic ■ First reprocessing plant in Europe ■ Goal ~Research and development in the field of reprocessing spent fuel originated from nuclear reactors ~Construction of a pilot plant

7 Reprocessing ? ■ Definition: Reprocessing = recycling ~Spent fuel (nuclear fuel) can be recycled ■ 97% of the material can be reused for electricity production (U and Pu) ■ 3% is waste and is vitrified, interim stored awaiting for disposal.

8 History of Eurochemic ■ 1957Constitution of Eurochemic ■ 1960Start construction ■ 1966Start up and active operation ■ 1974Shutdown ■ 1978Take-over by the Belgian State with the intention to continue reprocessing ■ 1984Constitution of Belgoprocess ■ 1985Belgoprocess takes over the personnel

9 ■ 1986Decision to end reprocessing in Belgium  Transfer actions to NIRAS ■ 1987Start decommissioning studies ■ 1989Start decommissioning pilot project ■ 1990Start decommissioning Eurochemic ■ 2008Start conventional demolition History of Eurochemic

10 Pilot project ■ Decommissioning of two smaller buildings for endproducts originated from reprocessing ~To demonstrate that decommissioning is feasible ~To demonstrate that costs can be managed ~To develop and optimise dismantling techniques ~To train personnel

11 Before and after

12 Main lessons learned ■ Emphasis should be put on: ~Decontamination of metal components ~Automation of concrete decontamin- ation

13 Clean-up of Eurochemic

14 ■ Main data ~Length 90 m, width 27 m, height 27 m ~Volume: m³ ~Concrete volume: m³ ~Concrete surface: m² ~Metal: ton ■ 7 levels, 40 main cells ■ 106 cell structures Clean-up of Eurochemic

15 ■ Radiological status in 1981 ~Contamination level up to 200 Bq/cm² (alpha) and 125 Bq/cm² (beta) ~Sometimes contamination in depth ~Hot spots up to several mSv/h ~No activation Clean-up of Eurochemic

16 Used techniques ■ Removal of metal components ■ Decontamination of concrete surfaces ■ Removal of contamination in depth ■ Removal of pipe penetrations ■ Techniques for working on heights

17 Removal of metal components

18 Removal of metal components

19 Decontamination of concrete surfaces

20 Decontamination of floor

21 Removal of contamina- tion in depth

22 Removal of pipe penetrations

23 Working at height

24 Working at height

25 To decontaminate ■ Main streams ~Metal ~Concrete

26 To decontaminate ■ Main streams ~Metal1.494 ton ~Concrete2.913 ton (incl. barytes blocs) (period 1988 – 2007)

27 Metal decontamination

28 Before and after

29 Concrete sampling

30 Clearance measures ■ 100 % surface measurement ■ Taking samples and analyses ■ Procedure is representative and approved by the department of fysical control ■ Control organism (Bel-V) subsidiary of FANC

31 Clearance measurement

32 Safety ■ Top priority for Belgoprocess ■ Radiation dose ■ Contamination risque ■ Conventional safety

33 Safety ■ Top priority for Belgoprocess ■ Radiation dose (average < 2 mSv/year.person over ) ■ Contamination risque (Protective clothes including full-face mask) ■ Conventional safety ~Circumstances as on a construction warf ~Vibration stress

34 Protective clothes

35 Protective clothes

36 Isolation of a module

37 Demolition ■ Method

38 Result: ■ Production streams ■ Men-hours ■ Budget ■ Planning

39 Result: production CONTAMINATED MATERIAL DECONTAMINATION OF MATERIALS RADIOACTIVE WASTE UNCONTAMINATED MATERIAL RECYCLINGWASTE PROCESSING & & && & & && DECOMMISSIONING

40 Result: production CONTAMINATED MATERIAL DECONTAMINATION OF MATERIALS RADIOACTIVE WASTE UNCONTAMINATED MATERIAL RECYCLINGWASTE PROCESSING & & && & & && 557 t t t145 t t1.675 t63% DECOMMISSIONING (31/12/2007) t t

41 Result: production CONTAMINATED MATERIAL DECONTAMINATION OF MATERIALS RADIOACTIVE WASTE UNCONTAMINATED MATERIAL RECYCLINGWASTE PROCESSING & & && & & && 557 t t t145 t t1.675 t63% -> 88% DECOMMISSIONING (31/12/2008) t t t

42 Result: men-hours ■ Initial estimation:403 man-year ■ Current estimation:600 man-year ■ Difference explained by: ~Decontamination until clearance ~Differences with the initial inventory ~Labour-intensive clearance measurements and procedures

43 Result: budget Initial estimation M€ 1992 M€ M€ 2008 after 2007 M€ 2008 Total M€ 2008 Ratio Decommissio ning costs 54,8 73,9115,130,0 145,1 1,96 Treatment (tarif 2008) 68,7 92,625,74,2 29,9 0,32 Totaal123,5 166,5140,834,2 175,0 1,05 Forced decontamination till clearance Less treatment, interim storage and disposal End result remains equal

44 Result: planning ■ Conventional demolition ~East part:september2008 ~Central part:einde2010 ~West part :einde2012 ~Distribution of water, air, steam,.. for neighbouring buildings remains

45 Result: planning

46 Ambitions ■ Safety ■ Environment ■ Socio-economical ■ Exploitation of the disposal site for category-A waste ■ International partner

47 Conclusion ■ Start of the conventional demolition of Eurochemic ■ In 2012 completely demolished ■ Cleaned-up historical heritage ■ Know-how to recycle >90% Belgoprocess and NIRAS decommission succesfully a nuclear plant

48 More information ■ Websites ~Eurochemicwww.eurochemic.be ~Belgoprocesswww.belgoprocess.be ~NIRASwww.nirond.be