1997 - Waste Package Specification for Ilw

NIREX REPORTN/007

WASTE PACKAGE SPECIFICATIONFOR INTERMEDIATE LEVEL WASTE

S V Barlow, N A Carr and S J Wisbey

May 2000

© United Kingdom Nirex Limited 2000

PREFACE

The role of Nirex is to provide environmentally sound options for the long-term management ofradioactive waste generated by the nation’s commercial, medical, research and defenceactivities. In order to assist waste producers who wish to package intermediate level wastes inaccordance with the principles of passive safety, Nirex has prepared documentation specifyingthe standards to be met.

This report sets out the Waste Package Specification for intermediate level waste prepared byNirex. Its purpose is to define the Nirex standard packages and to outline the requirements forpackaged wastes to be compatible with plans for interim storage, transport, handling andpotential disposal. This document has been produced by Nirex for publication. The informationin the document has been verified under procedures in accordance with ISO 9001. Theseprocedures have included independent peer review and internal review within Nirex.

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CONTENTS

1. INTRODUCTION................................................................................................................. 1

1.1. Background ............................................................................................................................. 11.2. Structure of Report .................................................................................................................. 11.3. Purpose of Waste Package Specification ................................................................................ 2

2. PACKAGING STANDARDS FOR INTERMEDIATE LEVEL WASTE ...................... 3

2.1. Scope of Waste Package Specification................................................................................... 32.2. Waste Management Phases ..................................................................................................... 32.3. Waste Package Types.............................................................................................................. 52.4. Non-standard Packages ........................................................................................................... 6

3. WASTE PACKAGE SPECIFICATION – GENERAL REQUIREMENTS ................. 11

3.1. General Requirements ........................................................................................................... 113.2. Quality Assurance ................................................................................................................. 143.3. Data Requirements ................................................................................................................ 14

4. WASTE PACKAGE SPECIFICATION........................................................................... 15

4.1. 500 litre Drum Waste Package .............................................................................................. 154.2. 3m3 Box Waste Package........................................................................................................ 164.3. 3m3 Drum Waste Package..................................................................................................... 174.4. 4 metre Box........................................................................................................................... 18

5. WASTEFORM SPECIFICATION.................................................................................... 20

5.1. Immobilisation of Radionuclides .......................................................................................... 205.2. Mechanical and Physical Properties ..................................................................................... 215.3. Chemical Containment.......................................................................................................... 225.4. Hazardous Materials ............................................................................................................. 225.5. Degradation Processes and Wasteform Stability................................................................... 225.6. Gas Generation...................................................................................................................... 235.7. Nuclear Properties................................................................................................................. 23

6. WASTE PACKAGE PRODUCTION PROCESS............................................................ 24

6.1. Quality Assurance for Waste Package Production................................................................ 246.2. Data Requirements ................................................................................................................ 26

7. OBTAINING PACKAGING ADVICE FROM NIREX.................................................. 32

7.1. Advice and Letters of Comfort.............................................................................................. 327.2. Initiating Packaging Advice.................................................................................................. 32

8. REFERENCES .................................................................................................................... 33

9. GLOSSARY OF TERMS ................................................................................................... 34

10. ABBREVIATIONS ............................................................................................................. 42

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1. INTRODUCTION

1.1. Background

The role of United Kingdom Nirex Limited (Nirex) is to provide the UK withenvironmentally sound options for the long-term management of radioactive wastegenerated by the nation’s commercial, medical, research and defence activities. This willinclude all intermediate level waste and some low level waste (ILW and LLW). Insupport of this role, Nirex has defined packaging standards in the form of thisspecification, which is issued to permit waste producers to package intermediate levelwastes in accordance with the principles of passive safety.

The approach adopted and promulgated by nuclear industry regulators, is for radioactivewastes to be converted into a passively safe form as soon as is reasonably practicable [1].In the case of ILW, this generally involves conditioning of wastes by their incorporationinto a solid, usually cementitious, matrix within a standard waste container: this is theprocess of waste packaging. Following packaging, wastes will be maintained in interimstorage, pending decisions on the preferred long-term waste management option [2].

This report has been prepared in order to define the waste packaging standards developedby Nirex to facilitate a standard approach to waste packaging. The document is intendedfor waste producers, regulators, Government Departments and all with an interest inradioactive waste management.

Throughout this report the general term ‘waste producer’ is used. This is taken to meanthe organisation that has responsibility for the packaging of waste; this may not always bethe organisation with ultimate liability for the waste.

1.2. Structure of Report

The remainder of this introductory section explains the reasons for providing this WastePackage Specification, the underlying principles that have been used in its preparationand its relationship with eventual Waste Acceptance Criteria that may be issued by theoperator of a disposal facility.

Section 2 provides an overview of the waste management phases that may be applicableto waste packages and which must as a consequence be covered by the Specification anddescribes the standard range of containers defined by Nirex for intermediate level waste.

Sections 3 through to 6 cover the Waste Package Specification itself.

§ Section 3: general requirements applicable to all packages;

§ Section 4: detailed requirements for specific waste package types;

§ Section 5: physical and chemical requirements to be met by the wasteform;

§ Section 6: quality arrangements covering the production and management of wastepackages.

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Section 7 provides a description of the mechanism by which waste producers may obtainadvice from Nirex and Section 8 contains a list of the references. A glossary of termsused throughout this document has been included in Section 9 and abbreviations used inthe report are defined in Section 10.

For further explanation of the rationale and derivation of the contents of this WastePackage Specification, a companion ‘derivation’ report is also published [3].

1.3. Purpose of Waste Package Specification

The Waste Package Specification has been developed by Nirex to define appropriatepackaging standards for intermediate level wastes. The Specification is comprehensiveand covers key aspects of the package including dimensions, handling and other features,performance requirements, wasteform characteristics, quality assurance and datarecording requirements.

The Waste Package Specification is not specific to a particular waste management option,but is derived from generic requirements for safe storage, transport, handling andpotential disposal. In addition the Specification also takes account of relevantinternational and national legislation, regulatory advice and other guidance and industrybest practice. The Waste Package Specification therefore facilitates the production ofwaste packages that are consistent with the principles of passive safety and that aresuitable for all phases of waste management.

Being generically based, the Waste Package Specification is designed to offer a robustenvelope against which waste producers may develop packaging proposals. Nirex assistswaste producers in this and is prepared to provide advice and endorsement of particularpackages. A formalised system for the provision of advice and endorsement has beenestablished and is described later.

The Waste Package Specification will be subject to periodic review as scientificknowledge of package performance increases, or when the bounding envelopes thatsupport the Specification become superseded by specific site and design information. It isenvisaged that the act of becoming site and design specific may lead to the removal ofsome of the conservatism from Specification criteria, as margins arising from currentuncertainties are removed.

From the foregoing it is evident that the Waste Package Specification must be treatedwith sufficient flexibility to permit it to evolve with time. It cannot therefore be entirelymandatory although certain provisions are, notably those for quality assurance andpackage identification. The Waste Package Specification in essence is guidance, which iswhy the interaction between waste producer and Nirex is a key element of the processleading to the production of conditioned waste packages.

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2. PACKAGING STANDARDS FOR INTERMEDIATE LEVEL WASTE

2.1. Scope of Waste Package Specification

In order to define packaging standards for intermediate level waste, it is necessary tohave an understanding of the phases of waste management that packaged waste mayexperience. Following its production, a waste package may be expected to undergo some,or all of the following phases:

§ Interim storage, usually at the site of arising.§ Transport to a disposal or storage facility.§ Handling and emplacement at the storage or disposal facility.§ Disposal1, where the package will provide the first barrier to release of activity.

Each phase will place its own demands on the waste package. These can be summarisedas follows.

2.2. Waste Management Phases

Interim storageInterim storage of packaged waste is the responsibility of the waste producer. During thisphase, packages are maintained within appropriate arrangements to ensure compliancewith site licence conditions and associated safety requirements. Packages are kept in amanner so that future transport, handling and potential disposal requirements will not becompromised.

TransportAlthough the siting and design of future long-term waste management facilities have yetto be finalised, the requirements and design of the transport system needed to transferpackaged waste between stores or to any future facilities are well understood.

Nirex has defined two generic types of waste package:

§ unshielded packages, which owing either to radiation levels or containmentrequirements, require remote handling and must be transported in a reusable shieldedtransport container;

§ shielded packages, which have built-in shielding and contain low-activity materials,so that the packages can be handled using conventional techniques and are transportpackages in their own right.

1Decisions on the preferred long-term waste management option for intermediate level waste will not bemade until after completion of Government consultation [2].

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The transport system, which may involve both road and rail transportation (andpotentially sea transport should the disposal facility be located on an off-shore island) isrequired to be able to accommodate both the above types of waste package. The transportsystem will need to meet all UK regulations for transport of radioactive materials, whichlike almost every other country are based on International Atomic Energy Agency(IAEA) Transport Regulations2 [4]. A further description of the standard waste packagesand transport containers is given in Section 2.3.

Handling and EmplacementAlthough the design of any future storage and/or disposal facility will not be completeduntil the preferred waste management option is identified, such a facility can be describedin terms of the following generic elements and operations:

§ receipt of transport packages, which will either be the re-usable shielded transportcontainer type or the shielded package type;

§ handling of the transport packages at surface facilities, which will comprise facilitiesfor receiving and checking of transport packages as well as management,administrative and other support functions;

§ transfer of transport packages to underground facilities via shaft or drift tunnel(assuming an underground facility is being considered);

§ in the case of packages transported inside re-usable shielded transport containers, theunloading of waste packages in a shielded inlet cell;

§ emplacement of waste packages in shielded vaults where operations will permitmonitoring and retrieval as necessary.

DisposalOne concept extensively researched and developed by Nirex is based on isolatingpackaged wastes in vaults excavated at depth in a stable geological environment. Theconcept makes use of engineered and natural barriers, working in conjunction, to achievethe necessary degree of long-term waste isolation and containment. This multiple-barrierapproach to containment takes credit for the fact that wastes are immobilised in anappropriate matrix, the immobilised wastes are packaged in metallic or concretecontainers and are emplaced in underground vaults. The vaults will be backfilled with acementitious grout material at an appropriate stage before sealing and backfillingaccesses from the surface.

In addition to these engineered barriers, the host rock will provide additional naturalbarriers, both physically and chemically, to the transport of radioactive material back tothe human environment. Following cessation of repository operations, it is expected thatthe waste packages will experience;

2 The Waste Package Specification for Intermediate Level Waste currently references IAEA Safety SeriesNo. 6 [4]. This is this version of the Transport Regulations that are incorporated into UK legislation. Whenthe more recently issued version, IAEA Safety Standards Series No. ST-1 [5] is adopted, the Specificationwill be revised accordingly.

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§ a period of care and maintenance under institutional control, prior to final closure;§ backfilling of the disposal vaults with a specially formulated cementitious grout

mixture to provide chemical conditioning and sorption of key radionuclides.

2.3. Waste Package Types

Nirex has defined a limited range of standard waste containers that are intended to besuitable for packaging the variety of ILW that arises in the UK. Standardisation isimportant as it enables handling and transport operations to be optimised around a limitednumber of variants, with consequent benefits in safety, logistics and economicsthroughout all the phases of waste management.

The four standard containers currently defined by Nirex for packaging ILW are listed inTable 2.1

Table 2.1: Nirex Standard Containers

WasteContainer

Typical Contents Overall Dimensions GrossMass3

Figure

500 litre Drum The normal container for mostoperational ILW

800 mm diameter x1200 mm height

2,000 kg 2.1

3m3 Box A larger container for solidwastes

1720 mm x 1720 mmplan x 1225 mm

height

12,000kg

2.2

3m3 Drum A larger container for in-drummixing and solidification ofliquid and sludge type wastes

1720 mm diameter x1225 mm height

12,000kg

2.3

4 metre Box For large items of waste,especially fromdecommissioning operations

4013 mm x 2438 mmplan x 2200 mm high

65,000kg

2.4

Note. When filled with conditioned waste, the above are described as “standardpackages”.

3 maximum mass of package filled with conditioned waste

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2.3.1. Unshielded packages

The 500 litre Drum, 3m3 Box and 3m3 Drum are typically manufactured from stainlesssteel. They are not designed to provide any radiation shielding in themselves hence whenfilled with waste these are known as unshielded packages. Handling and storage of thesepackages require remote handling facilities. For transport through the public domain, theunshielded waste packages will generally be placed within a shielded reusable transportcontainer to form a Type B package as defined in the Transport Regulations of the IAEA[4]. The shielded reusable transport containers are designed to contain either four 500litre Drums within a transport stillage, a single 3m3 Box or a single 3m3 Drum.

2.3.2. Shielded packages

The 4 metre Box is designed to meet the requirements for an Industrial Package freightcontainer as specified in the IAEA Transport Regulations [4]. The box is manufacturedfrom stainless steel and is provided with a concrete lining that can be varied in thicknessto suit the radioactivity of the contents. The radioactivity content is restricted to thatwhich can be classed as Low Specific Activity (LSA) or Surface Contaminated Objects(SCO) [as defined in 4] at the time of transport in the public domain. No additionaltransport container is required for the 4 metre Box because shielding is provided by thepackage itself in the form of the concrete liner. The box when filled with waste isdescribed as a shielded package since it can be handled by conventional means; the doserate external to the box is restricted consistent with its classification as an IndustrialPackage.

2.4. Non-standard Packages

A limited number of non-standard packages will also require transport, handling andpotential disposal. These non-standard packages are specifically designed by the wasteproducers, for wastes that cannot be packaged into standard waste containers. Thesedesigns may pre-date the establishment of Nirex standards or may be developed to fulfil aspecialised role. Non-standard packages will have to satisfy the safety requirements to anequivalent level of safety to that provided by the standard packages.

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Figure 2.1 – 500 litre Drum waste package

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Figure 2.2 - 3 m3 Box waste package

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Figure 2.3 - 3 m3 Drum waste package

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Figure 2.4 - 4 metre Box

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3. WASTE PACKAGE SPECIFICATION – GENERAL REQUIREMENTS

The Waste Package Specification should be used as the initial basis for developingpackaging strategies for discussion with Nirex. Consistent with the principles stated inSection 1.3, the Specification is not specific to a particular waste management option, butis derived from consideration of generic requirements for safe storage, transport, handlingand potential disposal. For clarity, general criteria applicable to all packages are given inthis section; criteria for specific Nirex standard packages are given in Section 4 andcriteria for the wasteform are given in Section 5.

Within the Specification both should and shall are used to preface criteria. When used inthe Specification they have the following meaning:§ shall denotes a criterion which is derived from consideration of a regulatory

requirement and/or which forms the basis for package standardisation;§ should denotes a criterion which is considered as a target, and for which variations

may be possible following discussion with Nirex.

3.1. General Requirements

This section covers general criteria that are applicable to all ILW packages. They shouldbe read in conjunction with the package-specific requirements described in Section 4.

3.1.1. Activity content

The activity level of the waste package contents shall not exceed that for ILW, asdescribed in the Government White Paper on radioactive waste management policy [1](i.e. waste with a radioactivity content which exceeds either the alpha or beta/gammaupper limits for LLW, but with a lower radioactivity and heat output than High LevelWaste (HLW) ).

In the case of shielded packages (the 4 metre Box), the contents shall be demonstrated tobe solid non-fissile LSA or SCO material, as defined in the IAEA Transport Regulations[4]. The quantity of LSA material or SCO in a single box shall be so restricted that theexternal radiation level at 3 m from the unshielded material does not exceed 10 mSv/h.

3.1.2. Dose rate

No external dose rate limit is specified for unshielded waste packages.

Limitations are however imposed on the external dose rate from the transport package bythe IAEA Transport Regulations [4]. The dose rate at 1 m from the surface of thetransport package shall not exceed 0.1 mSv/h and the dose rate on its external surfaceshall not exceed 2 mSv/h; the above criteria being applicable at the time of transport.

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3.1.3. Heat output

The heat output from a waste package shall be limited to a value that will preventexcessive temperature rise within the waste package during the stages of interim storage,transport or disposal. Heat output limits for individual packages are given in Section 4.

3.1.4. Surface contamination

The non-fixed surface contamination, averaged over an area of 300 cm2 of any part of thesurface of any waste package, should not exceed the following:

4.0 Bq/cm2

0.4 Bq/cm2- beta, gamma and “low toxicity” alpha emitters- all other alpha emitters.

3.1.5. Venting

Waste packages, which contain material that leads to gas generation and which may besusceptible to significant over-pressurisation, shall be vented. If a vent is fitted it shouldbe designed to retain significant particulate activity.

3.1.6. Integrity

Waste packages shall be capable of being moved and handled safely prior to finalemplacement within a storage and/or disposal facility. The container should be designedso that:

§ following a period of storage on the waste-producing site, the waste containermaterial, its thickness and corrosion properties and the sealing system of the wastepackage shall meet the requirements for transport and for subsequent operations at afuture facility;

§ following emplacement in a facility, the mechanical integrity of the waste containershall be capable of being maintained for the duration of the operational period.

Best Practicable Means (BPM) shall be used to provide containment for solubleradionuclides thereafter.

This will place a requirement for the waste container to maintain its integrity for at least50 years in interim storage and for a further 50 years beyond that. The BPM requirementreflects the need for package integrity to be robust to a range of waste managementoptions including disposal in an underground repository.

3.1.7. Properties of the wasteform

In providing a wasteform, all reasonable measures shall be taken to:

§ ensure that radionuclides in the waste are immobilised and loose particulate materialis minimised;

§ exclude free liquids;

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§ minimise the presence and volume of voids (such as ullage, holes or spaces) withinthe waste package; and

§ control the fissile material content of the waste packages to ensure that it does notpresent a criticality hazard.

See Section 5 for a more detailed specification.

3.1.8. Impact performance

Requirements on impact performance of the unshielded waste package are as follows:

§ the unshielded waste package shall be capable of being dropped in any attitude from aheight of 0.3m onto a flat unyielding surface, whilst retaining its radioactive contents,and remain suitable for safe handling, transport and disposal;

§ the unshielded waste package shall be capable of being dropped in any attitude from aheight of 10m onto a flat unyielding surface with the loss of contents, in the form ofparticles smaller than 40 micrometre, no greater than that specified in Section 4;

§ the unshielded waste package should be capable of being dropped in any attitudefrom a height of 25m onto a flat unyielding surface with the loss of contents, in theform of particles smaller than 100 micrometre, no greater than that specified inSection 4.

The limits of loss of content are defined in terms of A2, which is a measure of activitylinked to possible exposure pathways defined in the IAEA Transport Regulations. See theGlossary for the definition of A2.

The impact performance of the shielded package is controlled by virtue of itsclassification as an Industrial Package and consequential restrictions on the form of thecontents [4].

3.1.9. Fire performance

The unshielded waste package should be capable of withstanding a fully engulfing,1000oC pool fire of 1 hour duration, with the release of contents no greater than thatspecified in Section 4.

The fire performance of the shielded package is controlled by virtue of its classificationas an Industrial Package and consequential restrictions on the form of the contents [4].

3.1.10. Stackability

The waste package should be capable of being stacked six-high. The stacking load on thepackage is to be calculated as that resulting from its support of five similar packages,each at the maximum gross mass defined for the package type in Section 4. Under thisload the waste package should not exhibit any permanent deformation or abnormality thatwould render it incompatible with any other requirements defined in the Specification.

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3.1.11. Identification

The waste package shall be marked with a unique alpha-numeric identifier in a formatspecified by Nirex. Requirements on waste package identification are as follows:

§ the identifier shall be marked at the locations specified in Section 4;§ the identifier shall consist of ten alphanumeric characters arranged in a horizontal

sequence from left to right;§ the characters shall be 6-10 mm high;§ the characters shall be of the Optical Character Recognition type A (OCR-A) format

[6]. They shall be capable of being read on receipt at the repository and throughoutits operational period.

3.2. Quality Assurance

Quality Assurance arrangements shall be applied to all aspects of the packaging ofradioactive wastes that affect product quality. These arrangements shall be agreed withNirex prior to the start of the activities to which they relate. Specific requirements forQuality Assurance are described in Section 6.1.

3.3. Data Requirements

Information shall be recorded for each waste package and supplied to Nirex. Specificrequirements for the data to be recorded are described in Section 6.2.

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4. WASTE PACKAGE SPECIFICATION

The General Requirements for the Waste Package Specification are described in Section3 above. This section defines the specific requirements applicable to the four standardILW packages.

4.1. 500 litre Drum Waste Package

4.1.1. Heat output

The heat output from a 500 litre Drum waste package should not exceed 50 watts.

4.1.2. Dimensions

Overall dimensions of the 500 litre Drum waste package shall be:

Height mm3+mm15mm 1200 −

Diameter mm0mm6mm 800 +

−

4.1.3. Lifting feature

The 500 litre Drum shall incorporate a lifting feature in the form of a recessed flange.The flange is to be located on the top face of the drum and provide access to locate clawsof a lifting attachment. A 500 litre Drum waste package shall be capable of being liftedusing the lifting feature, with contact at no more than three equi-spaced points, withoutexhibiting any permanent deformation under a weight load equivalent to twice the grossmass limit of such packages.

4.1.4. Mass

The gross mass of a 500 litre Drum waste package should not exceed 2,000 kg.


The release of contents, in particles smaller than 40 micrometre shall be no greater than 5A2 in the event that a 500 litre Drum is dropped from 10m onto a flat unyielding surface(see Glossary for explanation of A2).

The release of contents, in particles smaller than 100 micrometre should be no greaterthan 20 A2 in the event that a 500 litre Drum is dropped from 25m onto a flat unyieldingsurface.


The release of contents should be no greater than 20 A2 in the event that a 500 litre Drumwaste package is engulfed in a 1000°C pool fire, for a duration of 1 hour.

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4.1.7. Location of identifier

Each 500 litre Drum shall be marked with its unique identifier specified in Section 3.1.11at four equally spaced positions on the vertical edge of the drum lifting feature.

4.2. 3m3 Box Waste Package

4.2.1. Heat output

The heat output from a 3m3 Box waste package should not exceed 200 watts.

4.2.2. Dimensions

Overall dimensions of the 3m3 Box waste package shall be:

Height mm3mm 3 - mm 1225 +

Plan 1720 mm 1720 mm - 10 mm+ 0 mm

-10 mm+ 0 mm×

Corner Radius 430 20 mm - 0 mm mm+

4.2.3. Lifting features

The 3m3 Box shall incorporate four equally spaced lifting points in the form of twistlockapertures. These shall be positioned on the top face of the 3m3 Box, mid-way along thesides. A 3m3 Box waste package shall be capable of being lifted using any three of thesetwistlock apertures, without exhibiting any permanent deformation under a weight loadequivalent to twice the gross mass limit for such packages.

4.2.4. Mass

The gross mass of a 3m3 Box waste package should not exceed 12,000 kg.


The release of contents, in particles smaller than 40 micrometre shall be no greater than20 A2 in the event that a 3m3 Box is dropped from 10m onto a flat unyielding surface (seeGlossary for explanation of A2).

The release of contents, in particles smaller than 100 micrometre should be no greaterthan 80 A2 in the event that a 3m3 Box is dropped from 25m onto a flat unyieldingsurface.


The release of contents, should be no greater than 80 A2 in the event that a 3m3 Boxwaste package is engulfed in a 1000°C pool fire, for a duration of 1 hour.

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Each 3m3 Box shall be marked with its unique identifier as specified in Section 3.1.11, oneach of the four sides of the box, at a mid-point and 50mm from the top edge.

4.3. 3m3 Drum Waste Package

4.3.1. Heat output

The heat output from a 3m3 Drum waste package should not exceed 200 watts.

4.3.2. Dimensions

Overall dimensions of the 3 m3 Drum waste package shall be:

Height 1225 mm - 3 mmmm+3

Diameter 1720 mm - 10 mm+ 0 mm


The 3m3 Drum shall incorporate four equally spaced lifting points in the form of twistlockapertures. These shall be positioned on the top face of the 3m3 Drum, on mutuallyorthogonal radii. A 3m3 Drum waste package shall be capable of being lifted using anythree of these twistlock apertures, without exhibiting any permanent deformation under aweight load equivalent to twice the gross mass limit for such packages.

4.3.4. Mass

The gross mass of a 3m3 Drum waste package should not exceed 12,000 kg.


The release of contents, in particles smaller than 40 micrometre shall be no greater than20 A2 in the event that a 3m3 Drum is dropped from 10m onto a flat unyielding surface(see Glossary for explanation of A2).

The release of contents, in particles smaller than 100 micrometre should be no greaterthan 80 A2 in the event that a 3m3 Drum is dropped from 25m onto a flat unyieldingsurface.


The release of contents should be no greater than 80 A2 in the event that a 3m3 Drumwaste package is engulfed in a 1000°C pool fire, for a duration of 1 hour.

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4.3.7. Location of identifierEach drum shall be marked with its unique identifier as specified in Section 3.1.11, atfour equally spaced positions on the side of the drum, 50 mm from the top edge.

4.4. 4 metre Box

4.4.1. Heat output

The heat output from a 4 metre Box waste package should not exceed 200 watts.

4.4.2. Dimensions

Overall dimensions of the 4 metre Box shall be:

Length 4013 mm 6 mm0 mm

−+

Width 2438 mm 5 mm0 mm

−+

Height 2200 mm 5 mm0 mm

−+


To allow lifting, handling and restraint during transport, corner fittings suitable for the boxmass and based on the British and International Standards for Freight Containers [7], shallbe provided at the eight corners of the box.

4.4.4. Mass

The gross mass of a 4 metre Box waste package shall not exceed 65,000 kg.


Minimum performance requirements are not specified for the 4 metre Box, as impactperformance will be controlled by virtue of its classification as an IAEA IndustrialPackage and consequential restriction to the carriage of material which can be classed asLSA or SCO [4].


Minimum performance requirements are not specified for the 4 metre Box, as fireperformance will be controlled by virtue of its classification as an IAEA IndustrialPackage and consequential restriction to the carriage of material which can be classed asLSA or SCO [4].

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Each 4 metre Box shall be marked with its unique identifier as specified in Section 3.1.11,on each of the four sides of the box, at the midpoint, along the bottom edge.

Each 4 metre Box shall also comply with the marking, labelling and placardingrequirements of the IAEA Transport Regulations [4], and with the marking and labellingrequirements for a freight container [8].

4.4.8. Transport Regulations

The 4 metre Box is intended to be a transport package and, as such, shall comply with theIAEA Transport Regulations [4] for an Industrial Package Type 2 (IP-2) designed toconform to the British and International Standards for Freight Containers [9], excludingdimensions and ratings.

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5. WASTEFORM SPECIFICATION

This section provides the Specification for the wasteform to augment the keyrequirements specified in Section 3.1.7.

5.1. Immobilisation of Radionuclides

The wasteform shall be designed to immobilise radionuclides such that the containmentprovided by the waste package should not be compromised by conditions or events that itmay encounter.

5.1.1. Immobilisation of radionuclides and particulates

All reasonable measures shall be taken to ensure that radionuclides in the waste areimmobilised and loose particulate material is minimised.

5.1.2. Response to an impact accident

The design and production of the wasteform should ensure that the quantity of potentiallymobile radionuclides present within a waste package at the time of an impact accident,including those generated as a result of the impact accident, is commensurate with thewaste package meeting the relevant radioactivity release limits specified in Section 4.

Impact performance of the 4 metre Box contents is controlled by its classification as anIAEA Industrial Package restricted to carriage of LSA material or SCO [4].

5.1.3. Response to a fire accident

The design and production of the wasteform for the unshielded packages, should ensurethat the quantity of potentially mobile radionuclides present within a waste package at thetime of a fire accident, including those generated as the result of a fire accident, iscommensurate with the waste package meeting the relevant radioactivity release limitsspecified in Section 4. In addition the wasteform should not burn or otherwise supportcombustion.

Fire performance of the 4 metre Box contents is controlled by its classification as anIAEA Industrial Package restricted to carriage of LSA material or SCO [4].

5.1.4. Free liquids

All reasonable measures shall be taken to exclude free liquids from the wasteform and thewaste package.

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5.2. Mechanical and Physical Properties

The wasteform shall be designed to provide the mechanical and physical propertiesnecessary to ensure appropriate long-term performance of the waste package understorage, transport and disposal conditions. It must be demonstrable that these mechanicaland physical properties will not be compromised by conditions that may be encounteredby the waste package.

5.2.1. Strength

The wasteform shall provide sufficient mechanical strength to allow the waste package tobe transported and handled, under normal and accident conditions, without affecting theability of the waste package to meet all the requirements of the Waste PackageSpecification.

5.2.2. Voidage

The design and production of the wasteform should ensure that the volume of voidagewithin the wasteform and the waste package (such as ullage, holes or spaces) isminimised.

5.2.3. Mass-transport properties

The wasteform shall be sufficiently permeable to allow gases generated by the wasteformto be released without changes that would cause it to fail to meet the requirements forimmobilisation of radionuclides. The permeability, diffusivity and porosity of thewasteform shall meet the requirement to provide best practicable means for containmentof mobile radionuclides within the waste package during the operational and post-closurephases of the repository.

5.2.4. Homogeneity/uniformity

Local concentrations of materials within the wasteform which may compromise anyaspect of the Waste Package Specification should be avoided.

5.2.5. MassThe combined mass of the wasteform and container, including all internal packagingcomponents, should not exceed the gross mass specified in Section 4.

5.2.6. Thermal conductivity

The thermal conductivity of the wasteform shall be sufficient to dissipate any heatgenerated within the package when emplaced in a backfilled repository withoutunacceptable temperature rise. Normally wasteforms with a thermal conductivity of 0.5Wm-1K-1 or greater will meet the envisaged design requirements.

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5.3. Chemical Containment

The wasteform shall be compatible with the dual physical and chemical barriers forcontainment of radionuclides and hazardous materials.

5.4. Hazardous Materials

The wasteform shall not contain, or have the potential to generate, hazardous materialsunless the packaging of the wasteform makes them safe. The means by which any ofthese materials is made safe shall be demonstrable under all conditions that may beencountered by the waste package.

5.5. Degradation Processes and Wasteform Stability

The wasteform should not degrade to a degree that will affect the ability of the wastepackage to meet all the requirements of the Waste Package Specification.

5.5.1. Cementitious wasteform dimensional stability

Dimensional changes of the wasteform should not compromise any aspects of the WastePackage Specification.

5.5.2. Corrosion

Any volume increase of the wasteform due to formation of solid corrosion productsshould not compromise any aspects of the Waste Package Specification.

5.5.3. Radiation stability

The effect of absorbed dose from self-irradiation and irradiation from surrounding wastepackages under storage and disposal conditions should not compromise any aspects of theWaste Package Specification.

5.5.4. Thermal effectsThe heat generated by a wasteform shall be sufficiently low to allow the heat generatedwithin a stack of packages to be dissipated without excessive temperature rise. Inaddition, the effects of localised heat sources within a wasteform should not degrade thepackage to the extent that would compromise any aspects of the Waste Package orWasteform Specification.

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5.6. Gas Generation

The total extent of gas generation by the wasteform should not compromise the capacityof the wasteform to immobilise radionuclides. Radioactive gas generation within thewasteform should not compromise the ability of the package or transport container tomeet radioactivity release restrictions under normal and accident conditions of handling,storage and transport, or to meet release restrictions subsequent to emplacement in therepository.

5.7. Nuclear Properties

5.7.1. External dose rate

The radionuclide content and nature of the wasteform should ensure that waste packageexternal dose rate limits as specified in Section 3.1.2 are complied with.

5.7.2. Criticality

The fissile material content of the waste shall ensure that a waste package does notpresent a criticality hazard during transport or during the operational phase of a disposalfacility, and that criticality shall not be a significant concern after repository closure.

The 4 metre Box contents shall comply with the requirements of the IAEA TransportRegulations [4] for solid non-fissile radioactive material packages.

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6. WASTE PACKAGE PRODUCTION PROCESS

In the role of future waste facility operator and specifier of packaging standards, Nirexneeds to be confident that each waste package being produced will meet the agreedpackaging intentions and will be acceptable following interim storage, for subsequenttransport, handling and potential disposal. The Quality Assurance (QA) and DataRecording requirements given in this Section are intended to provide this assurance.These aspects need to be addressed from the outset of the waste packaging process, as itis not possible to apply QA and many aspects of data recording retrospectively.

6.1. Quality Assurance for Waste Package Production

It is a requirement of the Nirex Quality Policy and of the Regulators that QualityAssurance arrangements be applied to the packaging of radioactive wastes that may bedisposed of in a deep waste repository.

The purpose of the QA arrangements is to provide confidence that the packaged wastehas the characteristics ascribed to it. This will enable Nirex to be assured that thecharacteristics of the packaged waste are as specified and can then be used in assessmentfor compliance against safety case criteria for transport, operation and disposal once theseare finalised.

6.1.1 Quality assurance arrangements

The waste producer shall establish and implement formal arrangements for all aspectsassociated with the packaging of waste which comply with the requirements of theappropriate ISO 9000 standard.

ISO 9000 is specified because it is an International Standard dealing with quality systemrequirements for both external and internal quality assurance purposes and representscurrent best practice in the nuclear and non-nuclear industries. ISO 9000 addressescontract review which is a key area in the relationship between Nirex as the ultimatedisposer of the waste and the waste producer organisations. Other key areas such asindependent verification, traceability, the need for external audit arise from ISO 9000 aswell as the need for a documented Quality Management System which identifies QualityAssurance Programmes, Quality Plans, procedures and records.

QA arrangements should cover all stages of the waste packaging process that can affectthe quality of the waste package. This includes waste characterisation, container design,process development, aspects of plant design, plant testing, commissioning and operations.

QA arrangements should be established and implemented at the earliest practicable timeand be consistent with the progress in establishing the processes for packaging waste.Nirex requires the provision of objective evidence that QA arrangements are beingdeveloped and implemented.

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6.1.2 Waste product specification

The waste producer shall establish, and provide to Nirex, Waste Product Specification(s).

The purpose of Waste Product Specifications is to describe the quality (properties andcomposition) and performance characteristics of each waste package type. These should besubmitted as part of the documentation to demonstrate effectiveness.

6.1.3 Demonstration of effectiveness

The waste producer shall demonstrate to Nirex that the Quality Management Systememployed is effective and that waste is being packaged in compliance with it.

Nirex in its role of potential waste facility operator and therefore the ultimate receiver ofthe packaged wastes, needs assurance that the quality of the products being produced fordisposal are compliant with its requirements.

Therefore in order to demonstrate the effectiveness of the Quality Management System,the waste producer shall provide to Nirex appropriate documentation and establish asystem of verification for all activities that have a bearing on the quality of the packagedwaste.

6.1.4 Assessment by Nirex

The waste producer shall provide, upon reasonable request, access for Nirex or its agreedagents to conduct assessment(s) of those activities affecting the quality of wastepackages.

The purpose of such assessments is to enable Nirex independently to establish that theQA arrangements in place, for activities affecting packaged waste quality, are consistentwith the requirements of the specified Quality Assurance systems. The nature, extent andscope of the assessments shall be sufficient to provide Nirex with the necessaryassurance.

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6.1.5 Method of compliance

Verification of the effective implementation of the Quality Management System and itscompliance with this specification shall be demonstrated through the provision ofobjective evidence such as by assessment.

Assessments may be by means of a review of documentation, by surveillance of activitiesat the works locations and/or by formal audits.

Assessments may be performed by Nirex or by a Nirex approved third party.

6.2. Data Requirements

This Section identifies the information that may need to be made available by the wasteproducer for waste packages. The required information will be generated throughout thevarious phases of waste management, from package conception, through packageproduction, storage, transport and eventual disposal.

6.2.1. Aims

The Specification for waste package data is required to facilitate demonstration ofconformance with relevant legislation and guidance, and to endeavour to ensure thatwaste packages – individually, in numbers and collectively – can be shown to meet therequirements for safe and cost effective storage, transport, handling and eventualdisposal. What needs to be recorded, therefore, are appropriate data that can be used toestablish, infer or predict package properties and performance under relevantcircumstances.

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A summary of general waste package data recording requirements is given below:

i) Data shall be recorded for each waste package.

ii) Each waste package shall be readily identifiable and be linked to data recorded forit.

iii) The recorded data shall:

- facilitate waste package tracking;- provide verification of conformance of a package with the relevant Waste

Product Specification or identify areas of non-conformance;- enable demonstration of conformance with the IAEA Transport

Regulations (as implemented by UK legislation);- meet the transport documentation requirements for special waste where

the radioactive waste is also special waste;- enable assessment of the safety of handling and storage;- meet the requirements of international safeguards;- enable demonstration of conformance with, and permit revision of the

repository operational safety assessment;- enable demonstration of conformance with the repository site licence and

discharge authorisations;- enable demonstration of conformance with, and permit revision of the

repository post-closure safety assessment;- enable demonstration of conformance with the repository disposal

authorisations;- enable demonstration of conformance with the Waste Acceptance Criteria

for disposal which will, in turn, be substantially based on safetyassessments (including criticality) covering the repository operational andpost-closure phases;

- facilitate provision of the disposal record.

iv) Of particular significance is a realistic and justifiable record of the nature andcontent of each package which:

- covers the physical, chemical and radionuclide element;- identifies or enables prediction of package properties and performance;- allows prediction of the evolution of the package characteristics with time,

and of the effect of interactions with other packages and repositorycomponents.

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6.2.2. Implementation

Each distinct type of packaged waste requires separate consideration in order to allow thedevelopment of a tailored system for data acquisition and recording. The system needs tocover the history of the packaged waste from the time of waste arising, through initialwaste characterisation, package conception and development, to package production,storage, transport and deep disposal.

The data which is to be available for each package is as follows:

a) Waste Package IdentifierUnique waste package identifier.

b) Waste- Description of raw waste.- Relevant UK Inventory Waste Stream Identifier.- Origin of the waste.- Identity of storage facility for raw waste (if applicable).

c) Waste Container- Type of waste container.- Waste container specification, including:

§ manufacturing drawings;§ dimensions;§ material specifications;§ container storage conditions.

d) Encapsulant, Capping and Conditioning MaterialEncapsulant, capping and conditioning material specification (as applicable), including:

§ chemical components;§ relevant physical properties;§ material storage conditions.

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e) Wasteform FormulationWasteform formulation, including (as applicable):

§ ratios of waste to encapsulant and conditioning materials;§ ratios of components of the encapsulant, capping and conditioning materials.

f) Process ConditionsProcess conditions, including (as applicable);

§ component temperatures;§ component addition regime;§ mixing regime;§ in-process movement times;§ process verification steps.

g) Nature of the Waste PackageDocumentation providing evidence of package properties and performance, including (asapplicable):

§ demonstration of conformance with the requirements for impact and fireperformance;

§ thermal conductivity;§ macro-voidage;§ thermal, chemical, radiation and mechanical stability;§ corrosion rates of waste package materials;§ gas generation and migration;§ mobility of radionuclides;§ compatibility with alkaline disposal environment;§ stability of filters and seals.

h) Waste Package Radionuclide Inventory- Activities (TBq per package) of radionuclides present in significant quantities at a

given reference date.- Methodology statement describing the establishment of package activities.- Form of radionuclides.

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i) Wasteform Component Inventory- Description of wasteform.- Declaration that wasteform is free of proscribed materials or that hazardous materials

have been made safe.- Inventory of components present in significant quantities, including (as applicable):

§ radioactive material in particulate form;§ encapsulant, capping and conditioning materials;§ metals;§ organic materials;§ inorganic materials;§ irradiated graphite.

- Methodology statement describing the establishment of wasteform componentinventories.

j) Waste Package Properties- Waste package classification.- Gross mass (kg).- Surface dose rate (mSv/h).- Non-fixed surface contamination levels (Bq/cm2 )- Heat output (watts), including non-radiogenic heat output.

k) Waste Product Specification- Waste Product Specification and supporting documentation.- Declaration of conformance or non-conformance with the Waste Product Specification.- Verification of conformance or non-conformance with the Waste Product Specification.- Details of remedial action taken in respect of a waste package initially deemed non-

conforming with the Waste Product Specification.- Details of non-conformance with Waste Product Specification.

l) Waste Package History- Date of production.- Identity of waste packaging plant(s).- Identify of waste package store(s).- Dates on which the waste package was placed in and removed from store(s).- Storage conditions.- Checks on the condition of the waste package in store.- Any abnormal occurrences or incidents involving waste package.- Any remedial action taken in respect of a waste package that becomes non-conforming.

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m) Criticality Safety- Criticality compliance assurance documentation and appropriate short and long-term

criticality safety cases.- Declaration of compliance or non-compliance with the criticality compliance assurance

documentation.- Verification of compliance or non-compliance with the criticality compliance assurance

documentation.- Details of remedial action taken to establish as compliant a waste package initially

deemed non-compliant with the criticality compliance assurance documentation.- Details of non-compliance with the criticality compliance assurance documentation.

n) Administrative- Customer contact.- Customer authorisation and agreement for transfer of waste package for disposal.

o) Transport- Consignment documentation covering transport of package. [see 10, 11].

p) International Safeguards [see ref. 12]- Safeguards category (safeguarded, non-safeguarded or exempt).- Measurement basis.- Batch designation.- Number of items.- Material description.- Weight of elements.- Uranium category.- Weight of fissile isotopes.- Obligation code.- Intended use of the material.- Date and time of movement, and identity of issuing and receiving material balance

area.

q) Special Wastes (if applicable) [see ref. 13]- Consignment documentation.

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7. OBTAINING PACKAGING ADVICE FROM NIREX

7.1. Advice and Letters of Comfort

Waste producers are encouraged to discuss their detailed waste packaging plans withNirex at an early stage, in order to obtain independent advice on particular packagingproposals. Nirex is prepared to give advice on specific applications based on itsknowledge of waste package behaviour and performance requirements under storage,transport, handling and disposal conditions and from its experience obtained during theresearch and development of systems for the transportation, handling and disposal ofradioactive waste. This advice normally takes the form of one or more Letters of Advice,which are reports issued by Nirex following assessment of a waste packaging proposal.The advice identifies further information requirements, or may highlight issues that needfurther development before an assurance can be given.

Nirex is also prepared to provide assurances that the proposed waste packages areconsistent with the envisaged transport and disposal system. This assurance is provided inthe form of an endorsement known as a Letter of Comfort. The Letter of Comfortsignifies that the proposal has been subject to a systematic evaluation to confirm that it isconsistent with foreseen requirements for interim storage, transport, handling andpotential disposal.

7.2. Initiating Packaging Advice

Waste producers wishing to develop plans for the packaging of ILW are advised toestablish contact with Nirex at an early stage. Nirex advice will assist in the identificationof an optimum solution and the provision of a Letter of Comfort will demonstrate that thefuture waste management phases have been considered and meet Nirex requirements.

Further information on Nirex packaging advice and the role of the Letter of Comfort isgiven in the Nirex publication, The Packaging of Waste for Safe Long-Term Management[14].

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8. REFERENCES

1. H M Government. Review of Radioactive Waste Management Policy - FinalConclusions. Command 2919, 1995.

2. H M Government. Response to the House of Lords Select Committee Report onthe Management of Nuclear Waste. 25 October 1999.

3. United Kingdom Nirex Limited. Derivation of Waste Package Specification forIntermediate Level Waste. Nirex Report N/008.

4. International Atomic Energy Agency. Regulations for the Safe Transport ofRadioactive Material. Safety Series No. 6, 1985 Edition (as amended 1990).

5. International Atomic Energy Agency. Regulations for the Safe Transport ofRadioactive Material. Safety Standards Series No. ST-1, 1996 Edition.

6. British Standard Institution. Character Set OCR-A, Shapes and Dimensions ofthe Printed Image. BS 5464 Part 1: 1977 (1984).

7. British Standard Institution. British Standard Freight Containers, Specificationfor Corner Fittings for Series 1 Freight Containers. BS 3951: Part 1: Section1.2: 1985 - Also published as ISO 1161:1984.

8. HM Government, Health and Safety. The Freight Containers (SafetyConvention) Regulations 1984. SI 1890.

9. British Standard Institution. British Standard Freight Containers, Specificationand Testing of Series 1 Freight Containers - General Cargo Containers forGeneral Purposes. BS 3951: Part 2: Section 2.1: 1991 - Also published as ISO1496/1:1990.

10. HM Government. The Radioactive Material (Road Transport) (Great Britain)Regulations 1996. SI 1996 No. 1350.

11. HM Government. The Packaging, Labelling and Carriage of RadioactiveMaterial by Rail Regulations 1996. SI 1996 No. 2090.

12. European Commission. Commission Regulation (Euratom) No. 3227/76 of19 October 1996 concerning the application of the provisions on EuratomSafeguards.

13. HM Government. The Special Waste Regulations 1996. SI 1996 No. 972.

14. United Kingdom Nirex Limited. The Packaging of Waste for Safe Long-TermManagement. Nirex Report N/006.

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9. GLOSSARY OF TERMS

A2

A2 is a measure of activity linked to possible exposure pathways defined in IAEATransport Regulations. It is used by IAEA to set contents limits for Type A packages andto limit the maximum allowable activity release from a Type B package. A2 is usedwithin the Waste Package Specification to define maximum releases from unshieldedpackages under impact and fire conditions.

Activity

Activity is the rate of nuclear transformations or transitions occurring in a radioactivesource. The SI unit of activity is becquerel (Bq).

Alpha emitter

An alpha emitter is a radionuclide that decays through emission of alpha radiation.

Alpha radiation

Alpha radiation consists of streams of alpha particles, which are positively-charged atomsof helium.

Becquerel (Bq)

Becquerel is the SI unit for radioactivity. One becquerel is the activity of a quantity ofradioactive material in which one radionuclide decays per second.

Beta emitter

A beta emitter is a radionuclide that decays through emission of beta radiation.

Beta radiation

Beta radiation consists of streams of beta particles, which are high-speed electrons.

Best Practicable Means (BPM)

Best Practicable Means is that level of management and engineering control thatminimises, as far as practicable, the radiological impact of the option whilst takingaccount of a wider range of factors, including cost-effectiveness, technological status,operational safety, and social and environmental factors.

Conceptual stage

Conceptual Stage is the phase during which the waste producer is initially developing thepackaging concept for a specific waste stream.

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Conditions for Acceptance (CfA)

Those criteria relevant to the acceptance of waste packages for handling, storage anddisposal. Also known as Waste Acceptance Criteria.

Criticality

Criticality is a state in a radioactive substance, which contains a sufficiently largequantity of fissile material, in which a self-sustaining neutron chain reaction occurs.

Decommissioning

Actions taken at the end of the useful life of a nuclear facility in retiring it from service,with adequate regard for the health and safety of workers and members of the public, andprotection of the environment.

Decommissioning waste

Radioactive waste from decommissioning activities.

Dose equivalent

Dose equivalent is a measure of the biological effect of radiation, i.e. it takes into accountthe different effectiveness of the various radiations in causing harm to body tissues. TheSI unit of dose equivalent is Sievert (Sv).

Dose rate

Dose rate is the quantity of radiation, or dose, received within the body per unit time.When a dose rate relates to a dose equivalent received over a known period of time, theSI unit for dose rate is sievert/hour (Sv/h).

External radiation level - see dose rate

Fissile material

Fissile material is a material that undergoes fission under neutron irradiation.

Fission

Fission is the splitting of an atom into two (or more) radionuclides of approximately thesame mass. The fission process results in the release of energy, mainly in the form ofkinetic energy of the fission fragments, which is rapidly converted into thermal energy.

Gamma emitter

A gamma emitter is a radionuclide that decays through emission of gamma radiation.

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Gamma radiation

Gamma radiation is an electromagnetic radiation emitted after nuclear reactions or duringradioactive decay.

Gross mass

The gross mass of a waste package is the combined mass of the wasteform and wastecontainer, including all internal packaging components.

Half-life

Radioactive half-life is the time required for half the number of atoms of a radioactivesubstance to decay.

High Level Waste (HLW)

Waste produced from reprocessing irradiated nuclear fuel. It contains over 95% of theradioactivity in all waste arising from nuclear power generation. High level wastes are ofrelatively small volume but have considerable heat output.

Independent Verification

Independent Verification provides independent reviews confirming that activities whichmay affect product quality, have been properly carried out and have been recorded.

Industrial Package

An Industrial Package (IP) is one category of transport package defined by IAEATransport Regulations.

Industrial Packages may be Type 1 (IP-1), Type 2 (IP-2) or Type 3 (IP-3). Industrialpackages are restricted to the carriage of LSA or SCO material.

Immobilisation

Radioactivity present in waste is generally immobilised by converting the waste to a solidform. This reduces the potential for migration or dispersion of the activity by naturalprocesses during storage, transport, handling and disposal.

Intermediate Level Waste (ILW)

Waste with a radioactivity content which exceeds either of the upper limits for Low LevelWaste, but having a lower radioactivity and heat output than High Level Waste.

Letter of Advice (LoA)

A Letter of Advice is a document prepared by Nirex following the assessment of a wastepackaging proposal submitted by a waste producer. The LoA gives advice on thepackaging proposal, identifies further information requirements and/or highlights issuesthat need further development.

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Letter of Comfort (LoC)

A Letter of Comfort is a document, prepared by Nirex, which provides assurances to thewaste producer that the waste package proposed is compatible with Nirex plans, ascurrently foreseen, for the repository and associated transport system.

Low Level Waste (LLW)

Waste with a radioactivity content, which does not exceed 4x109 Bq/t of alpharadioactivity or 12x109 Bq/t of beta/gamma radioactivity, other than that acceptable fordisposal with household refuse (Very Low Level Waste).

Low Specific Activity (LSA) material

Radioactive material which by its nature has a limited specific activity (i.e. activity perunit mass of material), or radioactive material for which limits of estimated averagespecific activity apply. LSA is a material classification defined by IAEA TransportRegulations.

Low toxicity alpha emitter

The low toxicity alpha emitters are: natural uranium, depleted uranium, natural thorium,uranium-235 or uranium-238, thorium-232, thorium-228 and thorium-230 whencontained in ores and physical or chemical concentrates, and alpha emitting radionuclideswith a half-life less than 10 days.

Micrometre

One micrometre is a millionth of the SI unit of length, metre (m).

mSv/h

One milli-sievert per hour is a thousandth of the SI unit of dose rate, Sv/h.

Non-standard waste container

A container, designed by the waste producer, to package wastes that cannot be packagedinto one of the standard waste containers. The non-standard containers may pre-date theestablishment of Nirex standards or may be developed to fulfil a specialised role.

Operational waste

Radioactive waste produced during the normal operations of a nuclear facility.

Packaging

The preparation of radioactive waste for safe storage, transportation, handling anddisposal by means of enclosing a conditioned wasteform in a suitable container.

Passive Safety

A passively safe form is one in which the waste is chemically and physically stable andstored in containment and a manner which minimises the need for safety mechanisms,

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maintenance, monitoring and human intervention, and which facilitates retrieval for finaldisposal.

Permeability

Permeability is a measure of the rate at which a gas or a liquid moves under a pressuregradient through a porous material.

Porosity

The ratio of the aggregate volume of interstices or porous media to total volume.

Pre-operational stage

Pre-Operational Stage is the phase during which the waste producer is building the plantfor packaging a specific waste stream. The plant design will have been developed duringthe Project Pre-Commitment Stage.

Project pre-commitment stage

Project Pre-Commitment Stage is the phase during which the waste producer is designingthe packaging process for a specific waste stream. The packaging process will be basedon the packaging concept developed during the Conceptual Stage.

Quality Assurance Programme

A Quality Assurance Programme provides a description of the overall qualitymanagement system which provides quality assurance for a particular project at any stagein its life cycle.

Quality Management System

A quality management System is the overall system by which an organisation determines,implements and ensures quality.

Quality Plan

A Quality Plan describes or identifies technical requirements and the means by whichdocumentation of items, processes or services will be controlled.

Radioactive decay

Radioactive decay is the transformation of an unstable substance into a more stable form,usually accompanied by alpha or beta and/or gamma radiation.

Radionuclide

A radionuclide is an isotope of an element that is unstable and undergoes radioactivedecay.

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Shielded waste package

A shielded package is one which either has in-built shielding or contains low activitymaterials and may be handled by conventional techniques. In all cases shielded packagesare also transport packages in their own right.

ShieldingShielding is the protective use of materials to reduce radiations so that the dose rateoutside the shielding material is kept As Low As Reasonably Achievable (ALARA). Theamount of shielding required will therefore depend on the type of radiation, the activityof the source and on the dose rate which is acceptable outside the shielding material.

Sievert (Sv)

Sievert is the SI unit of dose equivalent.

Special Waste

In general terms, special wastes are those which are dangerous or difficult to handlebecause they include hazardous or toxic materials. The Special Waste Regulations 1996implement the European Hazardous Waste Directive 91/689/EEC, are intended toprovide an effective system for the control of such wastes from their production to theirfinal disposal or recovery.

Standard waste container

A container designed to be consistent with a Nirex Waste Package Specification. Nirexhas specified four standard waste packages for Intermediate Level Waste.

Stillage

A stillage is a metal frame designed to hold four 500 litre Drums so that they can behandled and stacked as a single unit.

Surface Contaminated Object (SCO)

A solid object which is not itself radioactive but which has radioactive materialdistributed on its surfaces. SCO is a material classification defined by IAEA TransportRegulations.

Thermal conductivity

Thermal conductivity is a measure of the flow rate of thermal energy through a materialin the presence of a temperature gradient. The SI unit of thermal conductivity is Wm-1K-1.

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Transport container

A reusable container into which waste packages are placed for transport, the whole thenqualifying as a transport package under the IAEA Transport Regulations.

Transport package

The complete assembly of the radioactive material and its outer packaging as defined inthe IAEA Transport Regulations.

Type A package

A Type A package may contain an activity up to A1 or A2 and must comply with therequirements for Type A packages given in the IAEA Transport Regulations. A Type Apackage simply shall provide containment for its radioactive contents during normaltransport conditions (i.e. where an incident resulting in minor mishaps of the packagemay occur).

Type B package

A Type B package may contain an activity that exceeds the A1 and A2 limits for Type Apackages and must comply with the requirements for Type B packages as given in theIAEA Transport Regulations.

Unshielded package

An unshielded package is one which, owing either to radiation levels or containmentrequirements, requires remote handling and is transported in a reusable transportcontainer.

Waste Acceptance CriteriaThose criteria relevant to the acceptance of waste packages for handling, storage anddisposal. See also Conditions for Acceptance.

Waste container

The vessel which remains in direct contact with the wasteform and is disposed of alongwith the wasteform.

Wasteform

The waste in the physical and chemical form in which it will be disposed of, includingany conditioning media but not including the waste container.

Waste package

The wasteform and its waste container as prepared for storage and disposal.

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Waste Product Specification

A document prepared by the waste producer which describes the quality (properties andcomposition) and performance characteristics of each distinct type of waste packageproduced in a waste packaging plant.

Waste producer

In the context of the Waste Package Specification, the waste producer is the organisationthat packages the waste. In some cases, the waste producer may also be the organisationthat produces the waste to be packaged.

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10. ABBREVIATIONS

Bq bequerel

CfA Conditions for Acceptance

IAEA International Atomic Energy Agency

ISO International Organisation for Standardisation

HLW High Level Waste

ILW Intermediate Level Waste

K degree Kelvin

kg kilogram

LLW Low Level Waste

LoA Letter of Advice

LoC Letter of Comfort

LSA Low Specific Activity

m metre

mm millimetre

cm centimetre

QA Quality Assurance

QMS Quality Management Systems

SCO Surface Contaminated Objects

SI unit 'Systeme Internationale' unit

Sv sievert

t metric tonne

W watt

WAC Waste Acceptance Criteria

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1997 - Waste Package Specification for Ilw

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