Strategic Guidance on the Management of LLW and ILW / LLW ...

More documents

Recommendations

Info

LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 22 of 585.2.1. Size Reduction [Ref. 5, 14, 15]Usage as standalone techniqueSurface contaminatedLLWAluminiumCopperMild steelMild steel (coated)Stainless steelILW/LLWStainless steel (coated)VolumetricallycontaminatedActivatedDescription of techniqueSize reduction is a set of techniques used to minimise the dimensions of an item or object. For pondfurniture, if not undertaken underwater size reduction is predominantly undertaken using so-called “coldcutting”mechanical techniques or laser cutting, to minimise the spread of contamination to atmosphere.Plasma cutting has been seen to be effective underwater as well as in dry environments.Examples of mechanical cold-cutting techniques used for size reduction of pond furniture include:• Mechanical saws (e.g. reciprocating saws) for size reduction of small or medium sized pond furniturecomponents.• Nibblers (which use reciprocation to nibble through small amounts of metal) used for thick mild orstainless steel components.• Diamond wire saws used for large components.Outcomes Advantages Disadvantages• Reduction in the size of pond furniturecomponents to facilitate further treatmentor disposal.• Secondary wastes are smaller volumes ofsolid metallic waste for treatment / disposaland tools / tool components.• Simple.• Applicable to widerange of metal types.• Applicable to wideactivity range.• Minimised likelihood ofcontamination transferrelative to “hot-cutting”techniques.• Simple and easy tomanage secondarywastes.• Use of manualtechniques may bedifficult in high doseenvironments.• Can be difficult todeploy successfullyfor items of complexgeometry.Technique used at:A company owned by UK Nuclear Waste Management LtdNOT PROTECTIVELY MARKED
LLW Repository LtdNational Waste ProgrammeNWP/REP/011Issue 2.1 – Jan 2013Page 23 of 585.2.2. Surface Washing [Ref. 5, 14, 15]Usage as standalone techniqueSurface contaminatedLLWAluminiumCopperMild steelMild steel (coated)Stainless steelILW/LLWStainless steel (coated)VolumetricallycontaminatedActivatedDescription of techniqueThis is a technique which uses low pressure water (at either high or low temperature) to remove any watersoluble and loose debris from the surface of contaminated items. This technique can be applied at closerange, at distance or remotely (depending on the space and dose constraints of the area). The efficacy ofcleaning can be improved by the addition of detergents and solvents to the water but this can make disposalof the liquid secondary waste more complex. This has been found to be most useful for the removal of bulksolids or sludges from the surfaces of metallic items.Outcomes Advantages Disadvantages• For LLW:o Waste metal decontaminated toEPR out-of-scope status forunrestricted release for re-use orrecycle; oro Waste metal decontaminated toenable further processing,recycling or disposal.• For ILW / LLW cross-boundary wastes:o Waste metal decontaminated toLLW classification to enable furtherprocessing, recycling or disposal.• Secondary wastes – could potentiallygenerate a large volume of radiologicallycontaminated aqueous spent washingliquors (potentially contaminated withdetergents and solvents).A company owned by UK Nuclear Waste Management Ltd• Simple.• Applicable to widerange of metal types.• Applicable to wideactivity range.• Can be appliedremotely or atdistance.• Cannot remove fixedcontamination.• Not useful forvolumetricallycontaminated oractivated metals(unless as precursorstep for furthertreatment).• Generates largevolume ofradiologicallycontaminatedaqueous wasterequiring disposal.• Potential for orphansecondary wastegeneration.• Effectiveness limitedby complexgeometries orinaccessible wastes.NOT PROTECTIVELY MARKED
Page 1 and 2: National Waste ProgrammeStr
Page 3 and 4: LLW Repository LtdNational Waste Pr
Page 21: LLW Repository LtdNational Waste Pr

Strategic Guidance on the Management of LLW and ILW / LLW ...

Create successful ePaper yourself

Delete template?

Save as template?