GLOSSARY[e1]
Overpack-A process which encapsulates damaged packages in a larger package.
500L drumUnshielded cylindrical waste package which has a volume of 500L. Normally contains ILW.
3m3 drumUnshielded cylindrical waste package which has a volume of 3m3. Normally contains immobilised radioactive ILW sludge.
3m3 boxUnshielded waste package which has a volume of 3m3. Normally contains solid radioactive ILW waste.
3D MappingA Non Destructive Testing method which emits waves and receives the reflected waves. Such method could detect surface cracks and dimensions of an object
BackfillingFilling the PGRC with concrete. This is envisaged to occur at the end
of the 300 year monitoring period.
ConcreteA cementitious based composite which consists of cement, water, coarse aggregate and fine aggregate.
ColdAn environment that contains levels of radiation that are suitable for
humans to work in.
ContainerAn empty stainless steel package which has no grout or any waste forms in it.
DecontaminationThe complete or partial removal of contamination by a deliberate
physical, chemical or biological process.
Direct Workers visually inspecting a package with the naked eye. Primarily
Viewingthrough an oil filled shielded window which provides protection from
radiation.
DPIDye Penetrant Inspection method is a Non Destructive Testing method. By allowing dye to seep into cracks, and cleaning the surface, one could identify the presence of a crack easily.
Encapsulation Immobilisation of solid waste by mixing it with a matrix material within a container in order to produce a more stable waste form.
GPRGround Penetrating Radar is a Non Destructive Testing method. By transmitting radio wave and receiving it, one could determine the attenuation of concrete. It is being used to monitor the curing of concrete structures.
GrabThree armed lifting crane to lift/move a 500L drum.
GroutA cementitious based composite used to immobilise waste. It mainly consists of cement, water and fine aggregate. This will be used in the Overpacking procedure.
Half-lifeThe time required for half the number of nuclei of a specific radionuclide to undergo radioactive decay.
HotAn environment that contains levels of radiation that are too high for
humans to work in.
HarwellCurrent (February 2007) home of Nirex, UK where ILW stored just below surface’ is being removed, inspected, and stored. This waste will be transferred to the PGRC when built.
IndirectVisual inspection of a package using indirect means such as cameras.
Viewing
ILWIntermediate Level (Radioactive) Waste; wastes with radioactivity levels exceeding the upper boundaries for Low Level Waste but which do not require heating to be taken into account in the design of storage or disposal.
ImmobilisationConversion of waste into a less mobile or non-mobile form by, for example grouting or encapsulating.
MagnoxGas cooled fission reactor using un-enriched uranium as fuel, with magnesium alloy as cladding, the reactor type used in the UK’s first generation nuclear power plants.
Master/SlaveTools currently used to inspect and rework waste drums that are being
Manipulator extracted from ‘just below surface’ storage at Harwell.
NirexUK Nirex Ltd. A company jointly owned by DEFRA and the DTI that advises nuclear site operators on the preparation of safety case submissions to the regulator for the conditioning and packaging of radioactive waste.
Oil filledAllows direct viewing into hot areas of the Inspection and
shieldedOverpacking Cells whilst providing protection from the dangerously
window high levels of radiation within the cells.
Overpack-A process which encapsulates damaged packages in a larger package.
PGRC Phased Geological Repository Concept is the concept facility which will manage radioactive waste in the long term, which includes storage, monitoring and backfilling in a phased geological disposal method..
RadionuclideA nucleus of an atom that possesses properties of spontaneous disintegration. Nuclei are distinguished by their mass and atomic number.
ReworkingMinor repair work on damaged packages and to prevent further minimise further degradation from occurring.
Sievert (Sv)The SI unit of radiation dose.
StillageA tool container for holdingusedto facilitate four 500L drums. The drums are only extracted from a stillage when being individually inspected in the Inspection Cell or overpacked in the Overpacking Cell.It is being used to enable stacking and transport of 500L drums more efficiently.
Storage VaultA facility within the PGRC which is being used to store the waste packages.
Transfer Tunnel The tunnel which connects all inspection cells together and with the overpacking cell. A rack and pinion system will be adopted.
Twist LockA crane locks into this feature to move/lift a package. A T-Lock is
(T-Lock)used on a 3m3 box, 3m3 drum and stillage.
Phased Geological Repository Concept (PGRC)PGRC is the concept facility which will manage radioactive waste in long term, which includes storage, monitoring and backfilling.
Minor ReworkingMinor repair work on damaged packages and to prevent further corrosionminimise further degradation from occurring..
GroutA cementitious based composite used to immobilise waste. It mainly consists of cement, water and fine aggregate. This will be used in the Overpacking procedure.
ConcreteA cementitious based composite which consists of cement, water, coarse aggregate and fine aggregate.
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