15 June 2012
Update on German research work on LSA provisions
Meeting of the European Association of Competent Authorities for transport of
radioctive material (EACA), June 26-27, 2012, Brugg, Switzerland
Frank Nitsche
Bundesamt fuer Strahlenschutz (BfS), Salzgitter, Germany
Uwe Büttner
Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS)mbH, Cologne, Germany
Florentin Lange
Consultant, Mataré Str. 3, 40667 Meerbusch, Germany
Introduction
The aim of the research work was mainly to question the justification of the leaching
test for LSA-III material as currently required by the IAEA Transport Regulations with
respect to its relevance to transport safety based on current experience and knowledge
and to develop solutions for suitable regulation changes without decreasing the level of
transport safety.
This document is an updated version of the short report for the European Competent
Authorities Association meeting on May 19-20, 2011 [1] about the same project. It
summarizes the main research results after completion of the comprehensive research
work which was performed in recent years in Germany [2], [3] and which includes
results of collaboration with other European research institutes in this field [4], [5], [6],
[7]. It contains also a first proposal for changes in TS-R-1 and TS-G-1.1.
Background
In accordance with the safety concept of the IAEA Transport Regulations TS-R-1 the
package as combination of packaging and radioactive contents has to provide required
safety functions in all conditions of transport. Since Type IP-2 packages and Type IP-3
packages only have to protect against loss or dispersal of their contents under normal
conditions of transport, IP packagings for LSA-II and LSA-III materials may have only
limited accident resistance. Consequently, the Transport Regulations specify material
properties required for LSA-II and LSA-III materials being mainly based on accident
considerations and limitation of potential radiological consequences.
Among other required material properties the Transport Regulations comprise a limitation of the specific activity of LSA-II material to 10-4 A2/g (10-5 A2/g for liquids) and to
210-3 A2/g for LSA-III. In addition, the following more restrictive requirements were introduced for LSA-III material in order to justify the higher specific activity limit for LSA-III
material compared to solid LSA-II material:

a limitation of LSA-III material to solid material only excluding powders ,

a higher degree of homogeneity of the activity distribution in LSA-III material (“essentially uniformly distributed”) when contained within a solid compact binding
agent compared to solid LSA-II material (“distributed throughout”) and

a limitation of the solubility of the material.
The latter requirement has to be demonstrated by a leaching test of a material sample
representing the entire contents of the package in water for one week and a following
analysis of the dissolved activity. As argument for this leaching test the associated Advisory Material TS-G-1.1 considers a scenario of sufficient rain intake into an IP package during transport to surround the package content for one week followed by a handling accident which leads to a partial loss of this water and to the intake of a specified
fraction of the released activity by a nearby person.
Objective
The justification of the assumptions of the leaching test and its relevance with respect
to transport safety have often been questioned. On behalf of the German competent
authorities Federal Ministry of Environment, Nature Conservation and Nuclear Safety
(BMU) and Federal Office for Radiation Protection (BfS) GRS has analysed the consistency and adequacy of TS-R-1 requirements for LSA-II und LSA-III material and of
the leaching test requirement in particular with respect to transport safety.
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In the case of LSA-II material it is quite apparent by reviewing the historical development and current Advisory Material (TS-G-1.1) that the specific activity limit of 10-4 A2/g
was introduced regarding transport and handling accidents connected with airborne release of radioactive material. In contrast, the corresponding reasoning for the justification of the 20-fold higher specific activity limit of 210-3 A2/g for LSA-III materials is not
that evident since the leaching test introduced into the Regulations in the early 70s of
last century is focussed on a material property which has hardly any connection with
the majority of accident sequences with airborne release.
Consequently, a major objective of the current project was to analyse potential accident
scenarios of LSA-III material with respect to radiological consequences in order to
judge whether

accident scenarios following a prior leaching process or with a subsequent leaching due to immersion may lead to an unacceptable exposure

the remaining requirements for LSA-III (only non-powder solids, required activity
distribution) are sufficient to guarantee a high level of transport safety

alternative regulatory requirements are needed to replace the leaching test.
Compared to the accident scenarios given in the Advisory Material TS-G-1.1 as a justification for the LSA-III requirements more detailed analyses have been carried out applying current knowledge on airborne release behaviour of powders, brittle materials
and liquids for different types of accident scenarios. These analyses and assessments
have been performed in a comprehensive and conservative way and do also include
considerations of various material types used as LSA-III material in practice to achieve
representative results.
Summary of results of accident scenario analyses and potential radiological consequences
Potential radiological consequences from accident conditions involving LSA-II or LSAIII material
may result from inhalation of airborne release. In the case of LSA-III
material for which a leaching test is required also accident scenarios resulting in
release of water with enhanced activity levels from leaching may contribute to
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exposure. Therefore the analysed transport accident scenarios performed in the research project were chosen with the following intentions:
1. To examine potential radiation exposure by inhalation of persons being nearby
to a severe accident either outdoor or indoor involving LSA-II and LSA-III packages with respect to the 50 mSv effective dose criterion of the Transport Regulations. For such kind of land-based transport accidents airborne release of respirable particulate is dominated by material properties which are independent of
a postulated leaching behaviour of the LSA material
2. To examine potential radiation exposure resulting from leaching scenarios under accident configurations. In each case it was assumed that the leaching behaviour of the material would not fulfil the leaching test requirement but would
have a 100-fold higher leach rate. The aim was to check whether a scientifically
well based consequence analysis may give any support to the current leaching
requirement.
Analysed accident scenarios and boundary conditions
Area 1: Transport and handling accidents with mechanical impact of IP packagings
containing LSA-II or LSA-III material (no water involved)
As package contents representative LSA-II or LSA-III materials with comparatively high
airborne release fractions following mechanical impact have been chosen. As average
specific activities of the radioactive contents the respective limits of 10-4 A2/g for LSA-II
and 2 10-3 A2/g for LSA-III have been assumed. In addition, the possible effect of locally
increased specific activities in conformance with the homogeneity requirements of
226.13 to 226.17 of TS-G-1.1 have been investigated by assuming that this very
volume part of the package is suffering the impact forces.
As LSA-II material a highly dispersible powdery material was assumed. Such kind of
material, e.g. ashes from incineration of radioactive wastes, would conform to the material requirements for LSA-II but is explicitly excluded for LSA-III materials. As representative and frequently used LSA-III material a cement/concrete matrix material has
been chosen on the basis of experimental investigations which included a large spectrum of other brittle materials. Data from extensive experimental programs to investigate the release behaviour of such materials are available [2], [3], [4] and have been
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applied to estimate airborne release fractions as function of the severity of impact, e.g.
equivalent drop height, and the mass of representative LSA-II or LSA-III materials in a
Type IP-2 or IP-3 packaging. The experiments included the drop of sheet steel packages of increasing size up to 200 l drums from drop heights up to 27 m to establish the
effect of the cladding and of the volume of the LSA material on the airborne release.
The analysed accident scenarios are

A road or rail accident involving an IP-2 or IP-3 package with either LSA-II or
LSA-III material resulting in a mechanical impact equivalent to the severity of
the 9 m drop test for Type B packages. To represent typical package sizes, e.g.
for the shipment of radioactive wastes, three internal volumes of 200 l, 1 m³ and
10 m³ were considered.

As handling accident the drop of an LSA-II or LSA-III package when lifted and
moved by crane in a storage hall. To simulate varying boundary conditions a
small hall with 300 m³ free volume (assumed drop height 3 m) and a large all
with 3000 m³ free volume (drop height 6 m) was considered.
The potential exposure via inhalation of airborne particulate radioactivity was determined for persons close to the accident location (outdoor scenario) and for personnel
within the storage hall and compared with the 50 mSv effective dose criterion (10-6 A2
intake) of the Transport Regulations.
Area 2: Transport and handling accidents of LSA-III packages involving the release of
water after penetrating into the package and a consecutive leaching period of 1 week

A scenario is analysed which considers the postulated sequence of events as
given in 601.2 of TS-G-1.1 as explanation for the required leaching test and its
pass criterion of 0.1 A2 activity in the leaching water after seven days (heavy
rain fall during normal transport operation  water penetrating into the
packaging  leaching attack during 7 days  then accident which leads to
partial loss of penetrated water  resulting radiation exposure of a person
nearby). In contrast to the modelling approach of the Advisory Material much
more severe conditions are postulated by assuming a 100-fold higher activity
content in the leaching water (10 A2), complete loss of penetrated water
following the handling accident (assumed drop from 3 m in small storage hall
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and from 6 m in large storage hall). The potential exposure of personnel in the
hall is assessed by applying a well founded modelling approach and data
regarding resulting airborne activity either after loss of water and evaporation
from a resulting pool on the floor or by a spray release from the impacting
package.

An accident of an inland waterway craft on a small navigable river is considered
which results in the submersion of an LSA-III package. Before recovery activity
is released from the damaged package by leaching during 7 days. A 100-fold
higher leaching rate of 10 A2 in 7 days is assumed compared to the pass
criterion of the leaching test (0.1 A2/week). Neglecting retention and dilution
effects from the usual bank filtration of drinking water a direct consumption of
river water by a person downstream from the accident location is assumed and
the resulting effective dose determined.
In summary it can be stated that conservative and covering scenarios have been taken
to achieve reliable results.
Potential radiation exposure from analysed scenarios
In each of the analysed scenarios a number of conservative assumptions are involved
when assessing the potential radiation exposure of persons close to the accident location. The scenarios were selected to cover conceivable accidents involving LSA-II and
LSA-III packages with very adverse circumstances. In all cases calculated effective
doses remain below the 50 mSv effective dose criterion of the Transport Regulation, often even substantially below. It should be emphasised that the selected scenarios and
associated boundary conditions can all be seen as very low probability events.
In the case of the scenario of an accident involving the drowning of a damaged LSA-III
package in a small navigable river for one week combined with an unrealistically high
leaching rate the exposure of an individual directly consuming river water downstream
would remain well below 1 mSv effective dose. This is reassuring because for such circumstances of public exposure a 1 mSv criterion could also be of relevance.
Main findings can be summarized as follows:
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
The current requirements of the Transport Regulations for LSA-II packages are
sufficient and effective to meet the high transport safety level as provided by
TS-R-1.

The 20-fold higher specific activity limit for LSA-III packages is fully justified
based on required material properties which do not include the leaching requirement.

.Potential radiological consequences of transport and handling accidents which
additionally involve a hypothetical leaching scenario but do not take credit of the
current solubility restriction for LSA-III material remain well below the 50 mSv
criterion of the Transport Regulations.

In summary, from the point of accident consequences and accordingly of
transport safety no significant contribution is associated with the current leaching requirement for LSA-III material.
Suggested changes to the Transport Regulations
Currently the required LSA-II and LSA-III material properties are specified in para. 409
of TS-R-1 (2009) and are essentially:
LSA-II (solids): The activity is distributed throughout and the estimated average activity
does not exceed 10-4 A2/g
LSA-III:
1. Solids excluding powders
2. The radioactive material is distributed throughout a solid or a collection of solid
objects, or is essentially uniformly distributed in a solid compact binding agent
(such as concrete bitumen, ceramic, etc.)
3. The radioactive material is relatively insoluble, or is intrinsically contained in a
relatively insoluble matrix, so that even under loss of packaging, the loss of ra7
dioactive material per package by leaching when placed in water for seven days
would not exceed 0.1 A2
4. The estimated average specific activity of the solid, excluding any shielding material, does not exceed 2 x 10-3 A2/g.
In short, for solid LSA-II material requirements concern the activity distribution and the
specific activity of the material. For LSA-III powdery material is excluded, the specific
activity may be 20-fold higher than for LSA-II material and a solubility limit is introduced
by limiting a leaching rate.
Regarding further requirements for shipments of LSA-II and LSA-III packages TS-R-1
also contains conveyance activity limits which distinguish between combustible and
non-combustible solids as well as contents restrictions due to dose rate limits at 3 m
distance from the unshielded LSA material.
On the grounds of the above described thorough investigations and assessments including analytical and experimental methods it can be concluded that the requirement
of a leaching test for LSA-III material is not justified from considerations of transport
safety. Experience of more than 40 years of transportation of such kinds of material
can also be judged as being supporting information. This requirement was originally introduced into the Transport Regulations in the 70th of last century with the intention to
justify the 20-fold higher specific activity limit for LSA-III compared to LSA-II. In essence, the leaching requirement can be withdrawn as required material property for
LSA-III because it does not result in enhanced transport safety and only adds an unjustified burden to demonstrate compliance. At the same time the recent and now finalized
research work concludes that the other above mentioned requirements of the Transport
Regulations are necessary and fully sufficient to achieve the goal of high transport
safety both for LSA-II and for LSA-III materials.
Therefore in this paper a modification of the IAEA Transport Regulations regarding the
solubility requirement and associated leaching test for LSA-III is proposed.
The suggested changes to TS-R-1 are quite limited:
In para. 409 (c) for LSA-III the requirement
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(ii)
The radioactive material is relatively insoluble, or is intrinsically contained in
a relatively insoluble matrix, so that even under loss of packaging, the loss of
radioactive material per package by leaching when placed in water for seven
days would not exceed 0.1 A2
should be deleted.
Associated with this change are essentially only changes to para. 601 “Requirements
for LSA-III Materials” which addresses the leaching test, to para. 701 which specifies
performance compliance with this test including LSA-III material and to the heading of
para.703 which includes reference to LSA-III material.
Advisory Material
The cancelling of the leaching test would, of course, also require a number of modifications in 226.9 and 601.2 of the Advisory Material TS-G-1.1. by presenting explanatory
information in 226 as proposed here as a first draft:
The LSA-III material requirements were introduced into the regulations in the early 70s
of last century. In the meantime much progress has been achieved internationally
regarding knowledge of the kind and characteristics of LSA-II and LSA-III materials and
their release behaviour in accident conditions. It has been demonstrated that the factor
of 20 in specific activity limit of LSA-III material compared to solid LSA-II has sufficient
safety margins. These safety margins result from other currently required material
properties than those involved in the previously required leaching test, e. g. activity
distribution within the material and restriction to solids excluding powders.
The rationale given for this test requirement in the previous regulations was to restrict
leaching of activity by water postulated to have penetrated into the packaging during
transport operations. The limited solubility had to be demonstrated by a leaching test of
a material sample representing the entire contents of the package in water for one
week and a following analysis of the dissolved activity.
Compared to this accident scenario given as a justification for the LSA-III requirements
more detailed analyses of different types of accident scenarios have been carried out
applying current knowledge on airborne release behaviour of powders, brittle materials
and other applied LSA-II and LSA-III materials [4], [5], [6], [7]]. The low relevance of the
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limited solubility of solid LSA material for transport safety compared to the potential of
airborne release from mechanical impact has been verified by scenario analyses of
potential radiological consequences from transport and handling accidents. In these
analyses no scenario has been identified which could lead to an activity intake of
10-6 A2 (equivalent to 50 mSv effective dose) due to a lacking leaching test [1], [2], [3].
In conclusion, with a deletion of the leaching test requirement for LSA-III material the
IAEA Transport Regulations still guarantee a high level of safety for IP-2 and IP-3
packages which is fully consistent with that of other package types of the Transport
Regulations.
Conclusions
In this paper a modification of the IAEA Transport Regulations regarding the solubility
requirement and associated leaching test for LSA-III is proposed. The main findings
and conclusions are based on comprehensive research work which was performed in
recent years in Germany and which includes results of collaborations with other European research institutions in this field. For packages with LSA-III material it can be
concluded that the achieved high level of transport safety is not connected with the currently required limited solubility of the material but is resulting from the other required
material properties. Therefore the performance of the leaching test for LSA-III material
does not contribute to the requested safety level and can be omitted without decreasing the level of transport safety. This would help to simplify the Transport Regulations
and to overcome difficulties regarding different interpretations and implementations of
the leaching test in practice especially for radioactive waste.
References
[1]
W. Brücher, U. Büttner, (GRS, Germany), F. Lange, (Consultant,
Germany)
Review of LSA-III Material Requirements according to the IAEA Transport
Regulations with Respect to Transport Safety – Final Results. 11.5.2011
10
[2]
W. Brücher, U. Büttner, F.-N. Sentuc (GRS, Germany), F. Lange,
(Consultant, Germany)
Entwicklung eines Regeländerungsvorschlages für die Anforderungen in
den IAEA-Transportvorschriften TS-R-1 zum Auslaugtest für LSA-III
Material, GRS – A – 3599 Bericht, May 2011
[3]
W. Brücher, U. Büttner (GRS, Germany), F. Lange (Consultant, Germany)
Review of Material Requirements of the IAEA Transport Regulations for
LSA-II and LSA-III, PATRAM 2010 Symposium, 4 – 8 October 2010,
London, UK
[4]
F. Lange, R. Martens, (GRS, Germany), E. Hörmann, (Consultant,
Germany), W. Koch, O. Nolte, (Fraunhofer – ITEM , Hanover Germany),
I.Gray (Consultant, UK), C. Ringot, (Consultant, France), N. Carr (Nirex,
Harwell, UK), L. van Velzen (NRG Petten, Netherlands), S. Hughes,
(NRPB Chilton, UK)
Improvement of the Radiological and Experimental Basis to Further
Develop the Requirements of the IAEA Transport Regulations for
LSA/SCO Materials – Final Report, Commission of the European
Communities, Customer´s Contract No.: 4.1020/D/01-0021 2003
[ 5]
F. Lange, R. Martens, (GRS, Germany), E. Hörmann, (Consultant,
Germany), W. Koch, O. Nolte, (Fraunhofer – ITEM , Hanover Germany),
P. Malesys (COGEMA LOGISTICS, St. Quentin, France), S. Hughes,
(NRPB Chilton, UK)
Development of Methodologies and Small Scale Demonstration Tests for
the Assessment of Aerosol-Borne Release of Radioactive Materials in
Different Transport Situations – Final Report, Commission of the
European Communities, Customer´s Contract No.: 4.1020/D/02-002, 2004
[6]
F. Lange, H.-J. Fett, R. Martens (GRS, Germany), W. Koch, O. Nolte
(Fraunhofer ITEM, Hanover, Germany)
Assessment, Evaluation and further Development of the Safe Transport of
Radioactive Material: Methods and Tools Applied for Radioactive Material
11
Transport Risk Analysis Purposes, Final Report of the Research Project
SR 2479 (Working Area 4), GRS – A – 3378 / IV, June 2007
[7]
F. Lange, R. Martens, (GRS, Germany), O. Nolte, H. Loedding, W. Koch,
(Fraunhofer ITEM, Hanover, Germany)
Testing of packages with LSA materials in very severe mechanical impact
conditions with measurement of airborne release, Packaging, Transport,
Storage & Security of Radioactive Materials, Vol. 18, No. 2, pp.59-71,
2007
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