Appendix CRF - Part 3 - Northamptonshire County Council

8.16.5 The likely conclusion is that the landfill can receive unlimited amounts of these
nuclides at up to 200 Bq/g without exceeding the radiological capacity before
reaching the physical capacity. For those highlighted nuclides their effect in
practice will be reduced by being parts of mixtures with other nuclides and at
average concentrations less than 200 Bq/g. Several of the most restrictive
nuclides are short half-life and will generally not feature in decommissioning
wastes in significant concentrations.
8.16.6 Notwithstanding the overall conclusion that capacity is not particularly restricted
in this case, the proposal is that the capacity of the landfill is subject to a total
capacity limit combined with a series of other conditions. The total capacity limit
would apply from the date of issue until closure of the landfill or until the capacity
is reached. The landfill would receive no more LLW under the permit once the
capacity limit is reached. The capacity limit cannot be expressed as a single
number because it depends on the mixture received up to any point in time, so
the proposal is for a continuously revised capacity limit based on individual
nuclides (including appropriate daughter chains). The total capacity limit would
be established using an authorised spreadsheet model agreed with the regulator.
The spreadsheet model would represent the most restrictive case from the risk
assessment and would produce as an output the remaining capacity of the landfill
on an individual nuclide basis given the exact wastes received to that point in
time. Prior to accepting any further waste the model would be used by the landfill
operator to determine that the consignment would not lead to a breach of the
total capacity limit. This approach has a number of features:
The approach requires a comprehensive level of waste characterisation by the
consignors, but this is considered practicable and is optimal for ensuring public
health is not impacted by imprecise waste assay. This is also sustainable
because future generations will receive comprehensive information on the
disposed nuclides enabling them to make informed decisions.
The approach cannot be expressed as a simple number and hence may be less
transparent to the public, but the approach is highly transparent and detailed to
the regulator.
The approach is “modern” in the sense that it aligns the authorisation with the risk
assessment. This is in line with proposals to use risk based approaches for RSA
exemptions orders, waste definitions, clearance definitions and nuclear site
delicensing conditions. Hence the criteria used to produce the waste, to
categorise the waste and to dispose of the waste are based on a consistent risk
based approach that can be expressed in common terms of risk and dose.
The approach is based on the total life cycle of the facility. This addresses a
potential public concern that the authorised capacity may “creep” upwards at the
point of annual reviews. Authorisation creep of this type was identified as a
concern from the pre-application stakeholder workshops.
Application for disposal of LLW including HV-VLLW under RSA 1993,
for the East Northants Resource Management Facility:
Supporting Information
July 2009
88
WS010001/ENRMF/CONSAPPCRF 407