The document provides an overview of the immobilization and storage of nuclear waste, detailing the types of radioactive waste, their generation sources, and management strategies. It discusses the processes of reprocessing, waste classification, and various storage solutions, including both interim and long-term geological disposal methods. The UK's approach to radioactive waste management involves community involvement, establishment of the Nuclear Decommissioning Authority, and recommendations for geological disposal facilities.

1. Immobilisation and Storage of Nuclear Waste Dr John Roberts Dalton Nuclear Institute The University of Manchester NI Rough Guide to the Nuclear Industry 2010

2. Radioactive Waste Generation Military programmes Hospitals and research laboratories Nuclear Energy Industry Mining and milling of uranium ores reprocessing of fuel discharged from reactors decommissioning

3. Massive Source of Energy In an AGR reactor 1 tonne of U is equivalent to 20,000 tonnes of coal In a fast reactor - equivalent to 2,000,000 tonnes of coal A typical nuclear power station requires 40 tonnes of fuel per year - one lorry load per fortnight An equivalent coal power station requires 3,000,000 tonnes per year - two train loads per day

4. Worldwide Nuclear Industry

5. UK Radwaste Sources

6. UK Radwaste Volumes

7. Nuclear Fuel Cycle Return to customers for final disposal Enrichment Conversion Uranium Ore Natural Uranium All plant requires final decommissioning Recycle Fuel (MOX) Electric Power Reactor Transport Reprocessing Spent Fuel Storage Waste Management Fuel Fabrication Recycled Uranium

8. Nuclear Reactor Fuel - Originally uranium metal but now many variations typically 75 tonnes for 1000 MWe Moderators - carbon, H 2 O, D 2 O Cladding - contains fuel and prevents release of radioactive fission products Coolant - gas or liquid circulated through core of reactor for heat extraction Control rods - usually B or Cd with large σ c Shield - usually steel and concrete used for radiation protection and pressure vessel

9. Magnox Fuel Assembly 1 fuel rod per assembly, Magnox cladding, U metal fuel

10. PWR Fuel Assembly 264 fuel rods per assembly, Zircaloy cladding, UO 2 fuel

11. AGR Fuel

12. Pebble Fuel

13. Storage of Spent Fuel Spent fuel is highly radioactive and very (thermally) hot Initially stored in ponds at the reactor site Water cools the rods and acts as shielding Can also be stored in dry stores with air cooling

14. Storage Pond Dungeness storage pond, Kent

15. Storage Pond THORP storage pond at Sellafield

16. Water Shielding

17. Reprocessing Only about 4% of U is burnt up 235 U content reduced to less than 1% Some Pu remains from fission reactions Reprocessing separates the U and Pu from waste products by chopping up the fuel rods and dissolving them in acid U can re-enriched Pu can blended with U to produce MOX fuel

18. LLW - Wastes not exceeding 4 GBq/t alpha or 12 GBq/t beta/gamma discarded equipment, tools, protective clothing ILW - Above levels of LLW but not significantly heat generating stripped/leached remains of cladding or PCM HLW - Significantly heat generating fission products UK Waste Classification

19. Challenges of Radioactive Waste

20. Total Waste Volume 2007

21. Waste by Activity Total conditioned waste volumes from each business activity Total volume 1,750,000 m 3 57% Commercial Reprocessing 30% Commercial Reactors 9% Research & Development 2% Ministry of Defence 1% Medical & Industrial <1% Fuel Fabrication & Uranium Enrichment

22. LLW

23. Low Level Waste

24. LLW Container

25. LLW Repository near Drigg

26. LLW Repository near Drigg

27. ILW

28. Magnox Fuel Assembly 1 fuel rod per assembly, Magnox cladding, U metal fuel

29. Magnox De-canning

30. Magnox Swarf

31. Magnox Swarf

32. Solid Waste

33. Transport of Drums

34. Testing of Drums

35. Container Testing • Tests are impact from 25 m and 1000 ˚C • Bounding hazards encompassed by these two criteria are: • building collapse • roof collapse • aircraft crash • train crash • explosives / explosive gases • crane failure / aggressive feature • seismic fault • train fire • flammable gases • explosion • electrical fire • package fire • overheating

36. Results

37. HLW

38. Vitrification of HLW

39. Storage of Canisters

40. Nuclear Power Generation 80 year lifetime use of electricity for 1 person generates this much high level waste

41. Dounreay

42. Dounreay Shaft

43. Dounreay Shaft - past Excavated in the 1950s during construction of under sea tunnel for the discharge of low level liquid effluent 4.6m diameter, 65m deep On completion a concrete plug was used to separate the shaft from the tunnel and it was allowed to fill up with groundwater In 1958 the Scottish Office authorised the UKAEA to use the shaft as a disposal facility for radioactive waste More than 11,000 disposals took place until 1977 Environmental legislation has been tightened and the UKAEA are now required to remove all waste from the Shaft

44. Dounreay Shaft 1984

45. Borehole Plan

46. Shaft Platform - Schematic

47. Shaft Platform - Actual

48. Shaft - Waste Retrieval The shaft was isolated in 2008 ahead of programme and budget Waste retrieval can now commence Radioactive conditions mean that everything must be done by remote control Complications include - quantity and diversity of the waste working depth amount of corrosion after 50 years Base of shaft is immersed in 60 m of contaminated water In March 2010 it was announced that waste retrieval will be deferred until the completion of the site license competition

49. Waste Retrieval Plant

50. What next ?? HLW and ILW can be successfully immobilised in either cement, glass or bespoke ceramics Where should the waste be moved to for storage (retrievable) or disposal (non-retrievable) ?

51. Possible Options Disposal in Space Disposal in Ice Sheets Disposal in Subduction Zones Direct Injection Disposal at Sea Sub-seabed Disposal Dilute and Disperse

52. Probable Options Indefinite Storage Near Surface Disposal (Phased) Deep Disposal Very-deep Borehole Disposal

53. Underground Storage USA have (de)selected Yucca Mountain South Korea have selected Gyeongju Finland have selected Olkiluoto Sweden has selected Forsmark France, Belgium and Switzerland all have experimental sites

54. What is the UK doing ? Set up a committee - CoRWM Committee for Radioactive Waste Management Presented recommendations to government in July 2006 Government accepted all the recommendations in November 2006

55. CoRWM Summary Geological disposal is the best form of long-term management Coupled with safe and secure interim storage Development of volunteerism/partnership approach to secure facility siting Government’s response Accepted CoRWM’s proposal on geological disposal Accepted need for safe and secure interim storage Supportive of exploring the concept of volunteerism/partnership arrangements (recognising that geological/scientific requirements must be met)

56. Nuclear Decommissioning Authority Established April 1st 2005 All civil nuclear liabilities Two aims reduce the predicted cost of nuclear clean-up maintain the required skillsbase £70 billion budget

57. NDA Sites

58. Hunterston A

59. Hunterston A Located near West Kilbride, 2 units 160 MWe each, first grid connection 1964, shutdown 1990 Area of 15 hectares Current site end state plans are removal of all waste and buildings to be cleared with the site delicensed, landscaped and available for alternate use Key dates 2006 - Construction of ILW store complete 2014 - All operational ILW retrieval/processing complete 2017 - Entry into care and maintenance stage 2090 - Final site clearance and closure

60. Hunterston ILW Store

61. Hunterston ILW Store

62. Sellafield

63. Sellafield Located on the West Cumbrian coast, supported the nuclear power programme since the 1940s. Operations include processing of fuels removed from nuclear power stations, mixed oxide (MOX) fuel fabrication and storage of nuclear materials and radioactive wastes Area of 262 hectares Site end state will be decommissioned to passively safe state with plutonium and uranium stored on site

64. Äspö Hard Rock Laboratory

65. Multibarrier Concept

66. Spent Fuel Canister

67. Phased Disposal Concept

68. Underground Access

69. Vault Concept

70. Very-Deep Borehole Disposal

71. Drill the first stage of the borehole Insert the casing. Pour in the cement basement. Drill the next stage of the borehole. Insert the casing. Pour in the cement basement Drill the next stage of the borehole Constructing the Borehole And so on, down to > 4 kms 0.6 - 0.8 m diameter Constructing the Borehole Drill the first stage of the borehole Insert the casing Pour in the cement basement Drill the next stage of the borehole Insert the casing Pour in the cement basement Drill the next stage of the borehole And so on, down to > 4 km

72. Placement of Canisters Insert the casing Insert the canisters Pour in the grout and allow it to set Placement of Canisters Insert the casing Insert the canisters Pour in the grout and allow it to set

73. Separation of Canisters Insert Bentonite clay Insert another stack of canisters Repeat until the bottom km of the borehole is filled 4 kms Separation of Canisters Insert Bentonite clay Insert another stack of canisters Repeat until the bottom km of the borehole is filled

74. Sealing the Borehole Pour in some backfill (crushed granite) Insert heater and seal the borehole Pour in more backfill and seal the borehole again 3 km deep (topmost canister) Fill the rest of the borehole with backfill Sealing the Borehole 3 km deep (topmost canister) Pour in some backfill (crushed granite) Insert heater and seal the borehole Pour in more backfill and seal the borehole again Fill the rest of the borehole with backfill

75. Natural Analogues I Isolating Clay 50 ancient tree stumps found preserved in Dunarobba, Italy Trees had grown 1.5 million years ago They had not yet begun to rot Clay isolated them from oxygen and water

76. Natural Analogues II Canadian deposit/repository Cigar Lake uranium deposit lies 430m below ground Thickness 1- 20 m Width 50 -100 m Length 2 km Surrounded by clay there is there no radiological trace at the surface

77. Natural Analogues III Fossil Reactors Most famous is in Oklo, Gabon A layer of uranium ore is sandwiched between sandstone and granite. Water trickling through moderated the neutrons allowing fission of the uranium A chain reaction occurred until the water was boiled away Reactor worked on and off for more than a million years HLW created held in place by the rocks, Pu had only travelled 3m in almost two billion years

78. Useful Websites http://www.nltv.co.uk http://www.nuclearliaison.com http://www.rwin.org.uk http://www.corwm.org.uk http://www.nda.gov.uk http://www.sellafield.com http://www.nuclearinst-ygn.com