Uranium Concentrates Industry Best Practice foravoiding contamination of Packages and Shipping
Containers in Multimodal Transports
INFORMATION PAPER
Dedicated to the safe, efficient and reliable transport of radioactive materials
WORLD NUCLEAR TRANSPORT INST I TUTE
WNTI
1. Introduction 4
2. Packages and packaging 5
3. Contaminants and Contamination 6
4. Recommended contamination limit 7
5. Measuring contamination 8
6. Preparation of packages regarding contamination 9
7. Preparation for loading of packages 10
8. Preparation of the shipping container loading area 11
9. Loading of packages into shipping containers at the mine site 12
10. Preparing shipping containers for transport from the mine site 13
11. Unloading of packages at converter 14
References 14
home contents
3
Uranium Concentrates Industry Best Practice foravoiding contamination of Packages and ShippingContainers in Multimodal TransportsTable of contents
1.1. Uranium oxide concentrate (UOC) is radioactive, and
hence is classified a “Class 7 Dangerous Good”. It is
a relatively weak emitter of radiation and is classified
as a “low specific activity (LSA-I)” radioactive
material. The management of exposure to and
contamination from sources of radiation forms an
essential component of the safe transport of
radioactive materials.
1.2. This guideline document addresses the issues
associated with managing contamination of
Packages and Shipping Containers in Multimodal
Transports.
home contents 1. Introduct ion
4
1. Introduction
2.1. A common type of package for transporting UOC is
a steel drum classified as IP-1, having tight fitting
sealed lids designed to minimise the potential for any
escape of powder or dust.
2.2. The steel drums have smooth sides that assist in ease
of decontamination of any non fixed contamination
on the outside.
2.3. For ease of shipment and additional protection, the
packagers are normally loaded in a shipping unit, a
20’ General Purpose (GP) shipping container.
2.4. In this document, the package shall mean the filled
drum.
2.5. The shipping container itself is not an integral part of
the packaging.
home contents 2. packages and packaging
5
2. Packages and packaging
3.1. Best practice requires that all packaging associated
with radioactive materials be as clean as possible.
Contaminants can be introduced onto packages and
into shipping containers through exposure to the
elements and through poor standards of associated
work practice and housekeeping.
3.2. Examples of contaminants include various forms of
dust, dirt, mud, residues of liquids, particulates
suspended in air, etc.
3.3. The cleanliness of the package and shipping
containers can be further compromised by
contaminants that may include radioactive
“contamination” as defined by the International
Atomic Energy Agency (IAEA): The IAEA Regulations
for the Safe Transport of Radioactive Material, 2009
Edition, TS-R-1, define contamination as being “the
presence of radioactive substance on a surface in
quantities in excess of 0.4Bq/cm2 for beta and
gamma emitters and low-toxicity alpha emitters",
such as natural uranium.
3.4. The IAEA Regulations for the Safe Transport of
Radioactive Material, 2009 Edition, TS-R-1, indicate
that the non-fixed contamination on the external
surface of any package shall be kept as low as
practicable and, under routine condition of transport
shall not exceed 4Bq/cm2 for beta and gamma
emitters and low-toxicity alpha emitters", such as
natural uranium (averaged over any 300 cm²).
home contents 3. contaminants and contamination
6
3. Contaminants and Contamination
4.1. Although not a regulation, the WNTI recommends as
a good practice to apply this 0.4Bq/cm² value
(averaged over any 300 cm²) to the package
(effectively reducing the admissible value for a
package surface by a factor 10), to the shipping
container, to relevant areas and to mobile
equipment. This will facilitate the return of the
shipping container for other uses, keep loading,
handling and storage areas clean and provide good
working conditions.
4.2. Minimising the transfer of or retention and collection
of contaminants on the package or shipping
containers can greatly assist in reducing the
likelihood for radioactive contamination.
4.3. There are two forms of radioactive contamination;
being fixed and non-fixed or transferable.
4.4. Fixed radioactive contamination can come from dust
or fine powder residues associated with, for
example, fertilisers or ceramic tiles that over time
may have become embedded, impregnated and
ground into relatively porous materials such as the
flooring of shipping containers.
4.5. Non-fixed radioactive contamination is material that
can be easily removed from the surface of a
package. It generally occurs in powder, dust or liquid
form, which may become airborne, settle or flow
anywhere, be carried away by people or equipment
and transferred to people, equipment, facilities and
conveyances... thus creating the potential for health,
community welfare, media issues. Non-fixed
radioactive contamination generally creates a greater
hazard than fixed radioactive contamination because
of its greater mobility. Therefore it should be
removed prior to shipment.
home contents 4. recommended contamination l imit
7
4. Recommended contamination limit
5.1 Uranium is an alpha emitter, but the immediate
long-lived decay chain of U-238 contains two alpha
emitters (U-238 and U-234) and two beta emitters
(Th-234 and Pa-234m). Secular equilibrium of these
radio nuclides is generally reached within some 6 to
8 months after extraction. If UOC is shipped shortly
after processing, only alpha measurements are
meaningful. Beta measurements should not be
attempted at the Consignor site. For shipment of
aged material close to secular equilibrium, on arrival
at the Converter site, both alpha and beta
measurements are acceptable; beta measurements
usually provide better accuracy.
5.2 For repeat shipments, the measuring methods should
be agreed between Consignor and Consignee,
occasionally comparing readings on the same items.
5.3 Alpha and beta contamination are measured
separately and are not “additive”.
5.4 Surface contamination can be detected and
measured using direct surface activity measurements
using a surface contamination meter or by taking
wipe tests.
5.5 Direct surface activity measurements usually measure
the level of fixed plus non-fixed radioactive
contamination, whereas wipe tests measure the level
of non-fixed radioactive contamination only.
5.6 A wipe test involves wiping off some of the non-
fixed radioactive contamination from a surface onto
a filter (made either from paper for smooth surfaces
or from fabric for rough surfaces), whose collected
activity is measured using an activity counter or rate
meter. This process usually involves making an
assumption of the fraction of total contamination
collected by the swipe. A typical value is 10%. It is
important that this assumption be documented.
5.7 Direct surface activity is measured using a surface
contamination meter. In order to measure the
desired source of activity, these devices should be
fitted with either an alpha or beta probe. Care must
be taken as a number of beta probes are also
sensitive to gamma radiation and hence will give a
false positive due to direct gamma emissions from
the UOC.
5.8 All measuring instruments should be calibrated
regularly as per manufacturer’s instructions or
regulatory requirements, and the calibration records
should be kept.
5.9 Regular checks of instruments must be performed
before using the equipment and in accordance with
the manufacturer’s instructions.
5.10 Measurements require the subtraction of
background radiation in the measurement area.
Failure to take into account subtraction of the
background measurement will result in erroneous
results. All readings, including the level of
background radiation, should be recorded.
Background for alpha contamination is usually close
to zero.
5.11 The detection limit for the measuring instrument
should be significantly below the required measuring
threshold. In other words, when checking for a
contamination standard of 0.4 Bq/cm2, an instrument
having a detection limit below 0.2 Bq/cm2 should be
used.
home contents 5. measuring contamination
8
5. Measuring contamination
6.1. Package types
6.1.1. Drum specifications are discussed in WNTI Industry
Good Practices for ISO Containers in Multimodal
Transports (Ref. [1]).
6.2. Preparation of drums
6.2.1 Prior to filling, drums should undergo a visual check
for suitability focussing on the lack of any visible
moisture or rust on the internal surfaces of the
drum, any rust, corrosion, punctures and/or visible
damage to the external surfaces, or defects with the
seam of the drum barrel or the jointing of the barrel
to the drum base and top collar which could lead to
failure of the package and the potential for a
leakage of uranium concentrate powder.
6.2.2 After filling and closing, the drums should be
cleaned, e.g. washed with water, dried and marked
in accordance with requirements.
6.2.3 After filling and closing, the external surfaces of the
drums should be tested as per the company’s
directive for non-fixed radioactive contamination
with adequate equipment. If the drums have been
stored outside in the open, additional care is
required when testing the underside of the drums.
6.2.4. The WNTI-recommended limit for surface
contamination is 0.4 Bq/cm2. Drums failing to meet
this criterion which are below the regulatory limit of
4 Bq/cm2 should be reviewed to determine if it is
acceptable to release them for shipment. Drums
exceeding the regulatory limit of 4 Bq/cm2 will
require remedial cleaning and re-testing prior to
acceptance.
6.2.5. Best practice would ideally see drums transferred
immediately from the drum filling plant directly into
shipping containers. Where that is not possible, the
drums filled with UOC, awaiting packing into
shipping containers should be stored undercover to
minimise contaminants such as moisture or
windborne dust as well as the potential for non-fixed
radioactive contamination. Failure to take this into
account may result in the need for rewashing and
retesting of the drums and associated preparatory
work ahead of packing the drums into shipping
containers.
home contents 6. preparat ion of packages regarding contamination
9
6. Preparation of packages regarding contamination
7.1 Suitability of shipping containers
7.1.1 Shipping containers may be contaminated by other
radioactive cargoes such as bulk or bagged fertilisers
or ceramic tiles that can leave residual traces of fixed
or non-fixed radioactive contamination.
7.1.2 Good practice requires that uranium producers
should always check as early as possible (and clean
or reject as necessary) shipping containers for
radioactive contamination prior to moving them to
clean areas and to loading them with packages of
UOC.
7.2 Contamination inspection
7.2.1 A reliable source of shipping containers that are
known to be clean (dirt and contamination) should
be secured. Nonetheless, a certain level of
assessment of the quality of the shipping container
should be performed. For remote locations, this
assessment should be completed before the shipping
containers are shipped to the site to prevent the
additional cost of receiving and returning a shipping
container that is not clean.
7.2.1 All inside surfaces shall be checked for any
attachments and protruding parts that might come
in contact with, and damage, the packages.
7.2.2. Prior to checking for radioactive contamination, the
inside and outside of the shipping container should
be cleaned of debris. Using water or liquids should
be avoided as it may shield alpha contaminants;
drying is essential before measurements.
7.2.3 After cleaning, the fixed plus non-fixed radiation
contamination levels inside the packed shipping
container may be measured. The level of natural
uranium, as determined by either Alpha or Beta
radiation measurements, should be less than the
WNTI-recommended free-release contamination level
of 0.4 Bq/cm2. In any case, this limit is applicable
when averaging over any area of 300 cm2 of any
part of the surface (ref. [1]).
7.2.4 The three interior shipping container walls and inside
of shipping container doors should be checked by
taking measurement tests. Take the wipe tests
preferably in the middle of the walls (laterally and
vertically).
7.2.6 Any shipping container found to have levels of
radioactive contamination above 0.4Bq/cm² but are
below the regulatory limit of 4 Bq/cm2 should be
reviewed to determine if it is acceptable to release
them for shipment. Any shipping container
exceeding the regulatory limit of 4 Bq/cm2 shall not
be accepted.
7.2.8 On completion of this pre-loading inspection, ensure
that the doors of the shipping container are closed
immediately to prevent the possibility of extraneous
contaminants entering.
home contents 7. preparat ion for loading of packages
1 0
7. Preparation for loading of packages
8.1 The shipping container loading area should be
cleaned thoroughly with water and a hard broom, or
with a hard water jet to remove extraneous materials
that could be carried into the shipping container by
personnel or equipment. It is preferable to have the
area covered with clean suitable washable floor
covering.
8.2 Movement by personnel or equipment across the
shipping container packing area should be limited
to essential traffic associated with the shipping
container loading process. All other traffic should
be redirected elsewhere.
11
8. Preparation of the shipping container loading area
home contents 8. Preparat ion of the shipping container loading area
9.1 Minimisation of the transfer of contaminants
9.1.1 Every care should be undertaken to minimise all
forms of contaminants that could be transferred
from the package storage area into shipping
containers.
9.1.2 Workers involved in the loading of packages into
shipping containers should wear appropriate clean
protective clothing (e.g. gloves, full body overalls and
other designated personal protective equipment that
may form part of the organisations standard work
safety requirements).
9.1.3 Best practice requires that packages of UOC should
not be loaded into shipping containers during
extremely windy or dusty outdoor conditions.
9.1.4 Ensure that tyres and wheels of any forklift
equipment being used are clean and free of
contaminants and contamination.
9.1.5 Forklift equipment must be fitted with approved
drum handling attachments. Under no circumstances
should the forklift tines be used for lifting, moving or
the placement of drums into shipping containers.
9.1.6 Drum placement configurations should be designed
to provide sufficient spacing to prevent interaction
between adjacent drum lids and locking rings during
transport that could contribute to failure of the drum
seal. Drum chime diameter larger than the rings is
recommended.
9.1.7 All material used for packing and securing of the
packages in the shipping container including timber
bracing, wedges, chipboard, plywood, strapping etc.
must be stored in a clean area prior to being used
and must be checked for contamination before use.
12
9. Loading of packages into shipping containers at the mine site
home contents 9. Loading of packages into shipping containers at the mine s ite
10.1.1 This section should be read in conjunction with
information provided in the Pre Shipment Inspection
checklist for ISO Container with cargo as referenced
in Appendix 4 of Ref. [1].
10.1.2 On completion of package loading and securing, all
extraneous materials associated with the packing
and securing process must be removed from the
shipping container. The method used to load and
secure the packages in the shipping container must
meet the securing requirements for the planned
mode of transport.
10.1.3 Any area in which the shipping container is due to
be stored before shipment must be inspected for
cleanliness. If the area is dirty then cleaning is
recommended. If the area has had any contact with
material suspected as being radioactive it may
require additional cleaning or checking for
radioactive contamination.
10.1.4 Check conformance of the shipping containers with
radioactive contamination standards immediately
prior to transporting the shipping containers from
the packing site by taking appropriate measurements
on all four vertical sides of the shipping container. If
the results detect any radioactive contamination, the
shipping container must be re-cleaned before
transport. The level of radioactive contamination
averaged over 300 cm2 of any external part of the
shipping container should not exceed 0.4Bq/cm2.
10.1.5 At each point of transfer throughout the supply
chain (mine to converter) each side of each shipping
container should be inspected for damage which
may have resulted from travel and handling. It is best
practice to take photographs of each shipping
container side inspected. Damage to shipping
containers must be reported to the Consignor.
Temporary repairs can generally be undertaken to
address minor damage, abrasions, small holes etc.,
but if spillage is suspected then radiation
measurements must be performed prior to any
action. The Consignor should report details relating
to the incident as per applicable regulatory and
safeguards requirements, and arrange recovery.
13
10. Preparing shipping containers for transport fromthe mine site
home contents 10. Preparing shipping containers for transport from the mine s ite
11.1 Preparation of the shipping containeroffloading area
11.1.1 The shipping container offloading area should be
easy to decontaminate and provide reasonable
protection against weather conditions so that any
contamination is not dispersed at opening; the best
practice is an indoors offloading area.
11.1.2 The shipping container offloading area should be
prepared in the same manner as the loading area
above. As spillage may have occurred during
transport, surfaces should be easy to decontaminate;
recovery equipment should be present such as
protective equipment, plastic sheets, empty drums,
vacuum cleaners, etc.
11.1.3 Movement by personnel and equipment across the
shipping container offloading area should be limited
to essential traffic associated with the package
unloading process. All other traffic should be
redirected elsewhere.
11.2 Unloading shipping containers
11.2.1 After opening the shipping container doors, check
for any signs of visible contamination such as spillage
of UOC powder from UOC packages. It is best
practice to be aware and alert for any potential leaks
or spillage during the unloading process.
11.2.2 If evidence of spillage is found it should be collected
and handled as per site policy. An investigation
should be undertaken to identify the source and
cause of the spilt material and the Consignor should
be informed of the spill.
11.2.3 Workers involved in the unloading of packages from
shipping containers should wear appropriate clean
protective clothing (e.g. gloves, full body overalls and
other designated personal protective equipment that
may form part of the organisations work safety
requirements).
11.2.4 Care must also be taken during the unloading of
packages from shipping containers to prevent the
contamination of the shipping container with
radioactive material being transferred from within
the receiving facility.
11.2.5 Ensure that the tires and wheels of any forklift
equipment being used are clean and free of
contaminants and contamination.
11.2.6 Forklift equipment must be fitted with approved
package handling attachments. Under no
circumstances should the forklift tines be used for
lifting, moving or the placement of drums from
shipping containers.
11.2.7 After offloading packages, check the shipping
container floor for evidence of spilt material. If spilt
material is detected, then it should be collected and
handled as per site policy. An investigation should be
undertaken to identify the source and cause of the
spilt material.
11.2.8 Take measurements inside of the shipping container
for radioactive contamination, to certify compliance
with free release requirements. If the level of the
total contamination of the shipping container is
greater than 0.4Bq/cm2, the shipping container will
require additional remedial cleaning and rechecking
for levels of radioactive contamination. See Ref. [1]
for a description of the direct fixed point
measurements required for free release of shipping
containers.
11.2.9 Record the radiation measurements as per internal
Converter policy, prepare and issue Container
Release Certificate refer to Appendix 2 Ref. [1]
ReferencesReference [1] WNTI Industry Good Practices for ISO
Containers in Multimodal Transports
14
11. Unloading of packages at converter
home contents 11. Unloading of packages at converter
Remo House310-312 Regent Street
London W1B 3AXUnited Kingdom
Tel: +44 (0)20 7580 1144Fax: +44 (0)20 7580 5365
Web: www.wnti.co.ukEmail: [email protected]
IP6_EN_MAR13_V1
WORLD NUCLEAR TRANSPORT INST I TUTE
WNTI
