Environmental Safety Case and Changes to Waste Acceptance

Date: 25th April 2012

Dr Richard Cummings – LLWR ESC Project Manager

Presentation to: Customer Forum

Presentation

Objective:

Discuss changes to waste acceptance arising from the 2011 ESC

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2011 Environmental Safety Case

• Major submission

• Delivered to Environment Agency on the 1st May 2011

• Available on LLWR website: www.llwrsite.com

Agency Review of 2011 ESC: Current Schedule

• ESC delivered 1st May 2011• Initial review: May to Jul 2011• Main technical review: Aug 2011 to Jul 2012• LLWR submit application for new permit: late 2012• Agency publish review: Mar 2013• New permit: Sep 2013

• Planning permission process running in parallel

Implementation of 2011 ESC

• 2011 ESC approved by LLWR – believe we should implement to ensure environmental safety

• Required in current Permit to do so• Implementing where consistent with current Permit• Implementation:

– As a ‘live’ safety case under change control– New waste acceptance requirements

Waste Acceptance in the ESC

• Waste acceptance requirements derived from assumptions and assessment results of the ESC

• Four workshops held with consignors in 2011

New Draft Waste Acceptance Criteria (WAC)

• New draft WAC based on 2011 ESC just issued for consultation along with an explanatory customer notice

• Rest of talk focuses on:– Background to changes– Changes to current WAC

and processes– Further changes after

revised permit issued

Approach

‘Within the bounds of what is environmentally safe, we have adopted an approach in the 2011 ESC that seeks to minimise, as far as practicable, the impact on consignors, whilst maximising the potential use of the LLWR for LLW disposal.

It remains the case, however, that there will be significant changes required that will affect consignors.’

Most Significant Implications of ESC

• Requirements:

1. To control the total radiological capacity of the vaults

2. To limit and/or have emplacement controls on certain consignments due to either their activity or (potential) voidage

• To limit local voidage in waste stacks (and hence differential settlement of the cap) and to limit radiological impacts

Key Components

• Key components of the implementation of new waste acceptance arrangements:– Revisions to the Waste Acceptance Criteria (WAC)– Revisions to the Waste Acceptance Process– Introduction of a revised Inventory Control Process– Introduction of an Emplacement Strategy to manage

certain consignments

Changes to Current WAC and Processes

• Putrescible materials• Waste degradation and

settlement• Non-radiological

materials• Asbestos

• Total radiological capacity

• Specific activity of consignments

• Activity heterogeneity• Fissile radionuclides

Putrescible Materials

• One percent limit by volume

• May accept more if supported by:– BAT assessment– Assessment of potential health implications

Waste Degradation and Settlement

• Controls required to limit cap settlement• Use of BAT to limit potential voidage• Combined control on inaccessible, compression and

biodegradation voidage• Total potential voidage not to exceed 20% unless

agreed in advance

Non-radiological Materials

• Hazardous Waste, Hazardous Substances and Non-Hazardous Pollutants

• In discussion with Environment Agency on impact assessment and acceptance

• Such materials will only be accepted following approval of a Waste Consignment Variation Form

• Will allow us to implement changes at an appropriate point

Asbestos

• The ESC proposed that asbestos wastes should be excluded unless treated or conditioned to produce a form that would be acceptable if released during coastal erosion

• Work underway to refine our approach to implementing this proposal

• Asbestos will only be accepted following approval of a Waste Consignment Variation Form

• Will allow us to implement changes at an appropriate point• Environment Agency is considering its position on the disposal

of asbestos at the LLWR

Total Radiological Capacity

• Will control total repository activity through allocations of capacity by waste stream

• Allocation at characterisation stage• Waste streams will be rejected if exceed or use disproportionate

amount of remaining capacity• Remaining capacity analysis will take into account expected

future disposals based on UKRWI• Checks against allocation will be made at consignment stage

Specific Activity of Consignments

• Need to limit specific activity of individual consignments using a ‘sum-of-fractions’ inequality

• Approval of a waste consignment via a Variation Form where sum of ratios of specific activities of individual radionuclides and their trigger levels (specified in WAC) exceeds one

• Will need to be supported by a strong BAT case

Activity Heterogeneity

• Explicit criterion added to follow regulatory guidance

• Reasonably practicable measures to limit items of waste to below the 4 and 12 GB/t LLW limits

Fissile Radionuclides

• Relaxed conditions on reduced set of nuclides

• No limit on mass of graphite in a consignment

Importance of Accurate Consignment Data

‘Provision by consignors of accurate data on activity, materials and potential voidage for individual waste consignments (rather than averages for waste streams) will be essential.’

Changes to Come

• Relating to asbestos• Relating to non-radiological hazardous materials• Refined approach to complexants• Revised controls on sealed sources• Arising from revised permit

Complexants

• Potentially enhance mobility of radionuclides• Present in decontamination agents• Under current Permit, can only accept with written permission –

will be issuing guidance to help with identification• ESC proposed accepting non-persistent types (at low

concentrations)• Working to justify non-zero quantitative limits on all types• Will be consulting with consignors on use and waste

characterisation

Sealed Sources

• ESC proposed relaxing limits on some radionuclides in sources previously agreed with Agency

• Hope to implement changes under revised permit

Conclusions

• New waste acceptance requirements arising from 2011 ESC being implemented

• Implementation phased• Significant changes affecting consignors• New draft disposal WAC issued for consultation• We want to engage with consignors to ensure

changes are as practical as possible whilst protecting repository capacity and safety

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