atw Vol. 63 (2018) | Issue 8/9 ı August/September
480
REPORT
factors such as the structuring along
exposure situations and the inclusion
of many situations with natural
radiation which had hitherto not been
regulated, it seemed to him that there
were no dramatic changes to the
regulation of the nuclear industry.
Goli-Schabnam Akbarian basically
agreed, nevertheless pointing out
there were some issues (such as the
new dose limit for the lens of the eye)
where a solution would have to be
found to demonstrate compliance in
practice. Jörg Feinhals, when looking
at clearance, took a balanced position:
changes were basically moderate but
there was some increase in risk for
nuclear industry due to the fact that
concerning some substances there
was a shift from unconditional to
specific clearance; the latter was liable
to be more prone to public controversy.
On the other hand, nuclear
industry could be happy that specific
clearance as such had been retained in
legislation at all. Jack Valentin tended
to agree that nuclear industry was not
overly affected. He said that in this
respect there was a clear divide
between the nuclear and non-nuclear
area and that most problems would
arise outside the nuclear industry. He
also mentioned that some changes
were likely to have an influence on
public perception. Ted Lazo agreed
and emphasised the role of stakeholder
participation, which he
expected to grow in importance; it
was essential, he noted, to take this
into account.
The chairman remarked that radiation
protection experts so far, in his
view, had not entirely succeeded in
educating the public, and asked how
participation could be meaningful
given the limited knowledge of the
average member of the public. Ted Lazo
responded that education in radiation
protection indeed was not feasible on a
general basis; how ever, his personal
experience from Fukushima had
shown that those persons actually
affected by a crisis were very knowledgeable
and had a good perception of
what mattered in radiation protection.
Jack Valentin agreed: it was essential to
utilise people's common sense. This
was supported by Jörg Feinhals who
emphasised that communication needed
to be kept easy, simple and truthful.
Statements by NGOs in Germany about
lethal effects of clearance under the
10-Micro sievert-concept showed that
much could go wrong if calculation
was done with inappropriate numbers.
Next, the topic of clearance vs.
exemption levels was brought up. The
BSS Directive (recital 37) follows the
philosophy that the activity concentration
limits for both clearance and
exemption should be the same. The
chairman stated this seemed logical to
him and asked whether this wasn't an
aspect of the new Directive which was
welcome to everyone. Jörg Feinhals explained
that there may be different
conditions and different reasons for
clearance and exemption assumptions
and limits. Historically, the – very
influential – values in the IAEA RS-G1.7
document were meant for exemption
and not for clearance of huge amounts
of materials. There was also an issue
about the efforts for licensing due to
the reduction of exemption values.
Jörg Feinhals explained that in nearly
all cases not the exemption values in
column 3 of the relevant table in
the Strahlenschutzverordnung (specific
activity) but the exemption values in
column 2 (total activity) are relevant
for the licensing procedure. These
exemption values are not changed.
Differences between exemption and
clearance are mainly based on different
scenarios for exemption (do I need
a license for a small amount of mass
with radio activity?) and clearance
(can I dispose of large amounts of
contaminated/activated material?).
Nevertheless, Jörg Feinhals saw a certain
benefit in adopting a plain and
easy approach by taking the same
values. Ted Lazo agreed and proposed
that a new terminology may be needed
to introduce the differentiation which
was necessary in some cases.
Finally, a participant asked about
averaging criteria. He stressed their
importance and asked whether any
international regulations will be published
to this issue. Jörg Feinhals agreed
about the relevance of averaging criteria
and noted that this topic has been
brought to the attention of the IAEA for
establishing guidance for member
states.
At the end of the session, there
was a strong final applause for the
excellent speakers.
Report: GRS Workshop
“Safety of Extended Dry Storage
of Spent Nuclear Fuel”
Klemens Hummelsheim, Florian Rowold and Maik Stuke
Since up to now all NPP-operating countries are lacking a disposal site for high-level waste and thus are confronted
with the necessity of prolonged storage periods, an increase of scientific working effort was notable in the past years.
From the German perspective, irradiated fuel assemblies from nuclear power plants are packed in transport and storage
casks, e.g. of CASTOR® type, following the wet storage in the spent fuel pool of the reactor. The originally planned
storage period of a maximum of 40 years will not be sufficient in all cases. According to the German Atomic Energy Act,
a license “may only be renewed on imperative grounds and after it has been discussed in the German Bundestag”. On the
technical side, the availability of all safety functions of the storage system and thus the compliance with the respective
safety goals of both the aged casks including their components and structures as well as the inventories have to be
demonstrated for the envisaged prolongation. Special and unique features of Germany’s spent fuel situation are the
very high burn-up of the fuel, the use of mixed oxide fuels (MOX) and a large variety in casks, fuel assembly types and
cladding materials. To address these technical aspects that may be important for extended storage, the Gesellschaft für
Anlagen- und Reaktorsicherheit (GRS) gGmbH in Garching initiated in 2017 an annual workshop. This year it took
place from 6 th to 8 th June entitled “Safety of Extended Dry Storage of Spent Nuclear Fuel”. Nearly 60 experts from
Report
Report: GRS Workshop “Safety of Extended Dry Storage of Spent Nuclear Fuel”
ı Klemens Hummelsheim, Florian Rowold and Maik Stuke
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