ILW disposal in the UK Presentation at IAEA TM-45865, September 2013 Cherry Tweed – Chief Scientific Advisor

UK Radioactive Waste Sources of radioactive waste –generation of electricity in nuclear power stations –production and processing of the nuclear fuel –use of radioactive materials industry medicine research –military nuclear programmes Safe and appropriate management requires a good understanding of the type and nature of the radioactive waste and materials to be managed 2

3 Government’s framework for managing higher activity radioactive waste through geological disposal NDA as implementing body committed to: –Programme of R&D –Development of RWMD into delivery organisation –Preparation and planning for geological disposal Communities invited to open (without commitment) discussions with Government –Voluntarism and partnership –Right of withdrawal Note: Policy does not cover Scotland Geological Disposal – UK Policy (2008)

4 Schematic of ‘Single facility’ for HAW

5 Baseline Timescales Baseline Programme First ILW waste emplacement – 2040 First HLW waste emplacement – 2075 If added to programme, first emplacement of spent fuel from new build – 2130 All dates are indicative. Exact timing will be agreed with host community

Illustrative geological disposal concept examples 6

UK ILW/LLW Concept

Opalinus Clay Concept

WIPP Bedded Salt Concept

National LLWR Facility near Drigg

Definitions - UK High level waste Radioactive wastes in which the temperature may rise significantly as a result of their radioactivity, so this factor has to be taken into account in the design of storage or disposal facilities Intermediate-level waste Radioactive wastes exceeding the upper activity boundaries for LLW but which do not need heat to be taken into account in the design of storage or disposal facilities Low-level waste Radioactive waste having a radioactive content not exceeding 4 gigabecquerels per tonne (GBq/te) of alpha or 12 GBq/te of beta/gamma activity

UK Inventory Pu, U and Spent Fuel are not wastes but are included in planning for geological disposal 12 MaterialPackaged volume (m 3 ) ( 2010 Baseline inventory) HLW6,910 ILW [1] [1] 490,000 LLW [2] [2] 13,800 Plutonium7,820 Uranium106,000 Spent Fuel6,400 [1][1] Based on total volume of existing ILW stocks when packaged and future ILW arisings [2][2] Low level waste that cannot be disposed of at LLWR

13 ILW – waste (examples) Magnox Swarf Hulls and Ends Legacy ponds

14 Usually encapsulated in: Cement –BFS/OPC –PFA/OPC Alternative processing Polymers (e.g. epoxy resins) High T processing (e.g. vitrification) Bitumen (not in UK) Non-encapsulated (Robust shielded containers) ILW – conditioning process Cutaway of cement encapsulated 500L ILW drum

15 ILW – physical characteristics Source 2010 RWI (mass) ~1/3 conditioned (Packaged and or treated)

16 High activity in short- term (Cs-137, Sr-90…) Sharp decrease after ~ years, highly dependent on waste stream Activity ~order of magnitude less than HLW plot Cs-137, Sr-90 Ni-63 Source 2010 RWI ILW – radiological characteristics Ni-59

Illustrative Risk Calculations – ILW concept in higher strength rock 17

Some regulatory requirements Record keeping –Regulation require comprehensive record-keeping with duplicates Human intrusion –assume that human intrusion after the period of authorisation is highly unlikely to occur –implement any practical measures that might reduce this likelihood still further –assess the potential consequences of human intrusion after the period of authorisation Post-closure monitoring –assurance of environmental safety must not depend on monitoring or surveillance – Subsequent monitoring is not ruled out, provided it does not produce an unacceptable effect on the environmental safety case

Planned/ongoing R&D on ILW Disposal Key radionuclides –C-14 –Uranium Wasteform evolution –Vitrified ILW Container performance –Corrosion studies Buffer/backfill –Long-term cement evolution System understanding –Nar-field component model