Where to go with Denmark’s radioactive waste?

25.03.2015

This was the issue tackled yesterday by policy-makers and scientists at a conference organised by Friends of the Earth Denmark (NOAH) in Copenhagen. The Oeko-Institut contributed two presentations. NOAH regretted that the Danish authorities responsible for the final disposal of radioactive wastes had withdrawn their participation in the conference at short notice, with the argument that they are now first considering whether long-term interim storage may be the preferable option.

Debate at the conference, however, focused not on interim storage but on the final repository concept that the Danish government has been preparing for several years. A formal Strategic Environmental Assessment (SEA) of that concept was conducted in October 2014. The SEA identifies possible sites at which to consign to final storage the radioactive material that will result largely from the country’s three research reactors that have now been shut down and are being dismantled. Numerous German institutions and individuals presented their views as input to the public participation procedure that formed part of the SEA.

Gerhard Schmidt, Senior Researcher at the Oeko-Institut, criticised in his presentation the classification of wastes which underpins the repository concept: “The concept is based on the assumption that we are dealing here with short-lived wastes that will decay within 300 years to activity levels below current clearance criteria. Our analyses, however, reveal that this only applies to two types of wastes in the Danish inventory. The great majority of the Danish radioactive wastes is long-lived and needs 100,000 years and longer for it to decay to levels below today’s clearance limits”.

One outcome of the classification of the wastes as short-lived is that current Danish plans envisage near-surface landfilling at depths between 0 (surface repository) and 100 metres (shallow repository). Accordingly, the site selection procedure has only considered such sites. The Oeko-Institut stresses, however, that final disposal of such wastes must be guided above all by their permanent containment and by their isolation from the biosphere over periods of more than one million years. Near-surface repositories cannot achieve those goals with the requisite reliability. The institute recommends that all Danish radioactive wastes are consigned to final storage in a single geological formation that possesses the required reliability over time. To that end, the limitation to a near-surface concept should be abandoned and the geological formation best suited to this purpose should be sought.

Beate Kallenbach-Herbert, Head of the Oeko-Institut’s Nuclear Engineering & Facility Safety Division, gave a presentation comparing the Danish repository concept with the nuclear waste management approach applied in Germany. She noted that a key challenge in final disposal is to gain the trust of the public and of stakeholders. She further underscored that the chosen concept and the selection of host rock formations and sites must follow good scientific practice and be guided by safety considerations. The two Swedish speakers also highlighted those aspects, noting that the Danish approach leaves much scope for improvement in this regard.

Presentations:

Öko-Institut’s take on the Danish concept for a final repository for low- and intermediate-level radioactive waste
Powerpoint presentation by Gerhard Schmidt

Nuclear waste management in Germany compared to nuclear waste management in Denmark
Powerpoint presentation by Beate Kallenbach-Herbert

Further information from the Oeko-Institut:

Working Paper “The Danish Inventory of radioactive waste and the required repository type”

Further information on permanent disposal on the focal-issue pages of the Oeko-Institut website

Contacts at the Oeko-Institut:

Beate Kallenbach-Herbert
Head of Division
Nuclear Engineering & Facility Safety
Oeko-Institut (Institute for Applied Ecology), Darmstadt office
Tel. +49 6151 8191-109
E-Mail: b.kallenbach--at--oeko.de

Gerhard Schmidt
Senior Researcher
Nuclear Engineering & Facility Safety
Oeko-Institut (Institute for Applied Ecology), Darmstadt office
Tel. +49 6151 8191-107
E-Mail: g.schmidt--at--oeko.de