atw 2018-09v3

inforum

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

More magazines by this user
Similar magazines