Great effort is being expended in investigating the science, technology and sites for high-level waste (HLW) disposal deep underground. A key recent focus for the efforts and progress was afforded by recent discussions at the international conference on the Safety of Radioactive Waste Management, organised by the International Atomic Energy Agency (IAEA).

As Carl-Magnus Larsson, CEO of the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), and conference chairman, said in his opening remarks to delegates, radwaste management “remains a focus of both attention and contention, including the final management of spent fuel that has been declared as waste.”

He added: “There is, however, continual development over the whole spectrum of activities that relate to waste management.”

Topics addressed at the conference ranged from policy and science to projects handling different levels of waste, but key themes debated also included: regulator engagement; straight stakeholder engagement to get to the most informed decision-making; how to get to social acceptance and hence a “social licence” for a disposal solution; and, approaches to shared facilities, such as multinational disposal facilities.

No country has yet built a long-term disposal facility nor has any offered to host regional or multinational disposal facilities for radioactive waste, though some nations are seeking the service of such complexes – in particular those with only smalls amounts of waste, as the conference heard in its opening session. An exception is cases where small volumes of spent fuel are legally required to be returned from research reactors to the country of origin.

The point was made that it may be prudent for the European Union (EU) to examine the issue of rationalised, if not centralised, disposal solutions as it was acknowledged that, logically, it is questioned why the nations of the region should be in pursuit of about 20 separate repositories.

Well away from Europe, interesting discussions around matters of taking international nuclear waste across borders have been, and continue to be, held in Australia (see box, left).

In many cases, though, notes the summary of the Policy & Strategy session of the conference, the import or export of almost all radioactive waste is prohibited by law and, consequently, national disposal solutions are pursued.

Finland was acknowledged as the country making most progress towards geological disposal of high-level waste, having a facility already under construction.

Broad scope, deep topic

At the IAEA’s Safety of Radioactive Waste Management conference, held in Vienna in November last year –16 years after the last such major IAEA event, and with no spent fuel having been disposed of yet – the discussions were wide-ranging and both the activities and perspectives of different countries were presented.

A brief review of activities since the last IAEA event, in 2000, in Spain, had the view there had been significant progress, although there are differences in the approaches undertaken by countries. A ‘great leap’ forward had been made in demonstrating safety through the safety case approach, now “well established as a best-practice” method with a supporting suite of safety standards.

But, despite the progress in broad approaches when it comes to building disposal facilities advances are happening only slowly, in most cases – again, except for in Finland, and perhaps Sweden. This slow progress has led to society as well as many in the waste management community to view the effort as mostly unsuccessful. But this is ‘unjustified,’ concludes the report on the latest event.

Still, even with greater understanding of long-term safety through studies, final disposal is recognised as ‘the only feasible solution’ so far, according to the IAEA’s summary. There is both the perception and reality that the amount of radioactive waste and spent fuel held in non-final storage increasing. “This may lead to consideration of storage as a long-term option, which is hardly justifiable with regard to inter-generational equity,” the summary observes.

The point was also made that reporting on radioactive waste generation and inventories is being performed to different standards despite the existence and availability of international waste classification systems. Therefore, harmonisation of standards was urged.

Concerns around the importance of developing and maintaining comprehensive inventories were also stressed, in the Policy & Strategy session, for a category that is a counter-point to cases of transporting waste – i.e. the special issue of legacy waste, which comprises “non-removable wastes” that call for in-situ disposal solutions.

Inventories, again, came up with regard to high-level waste (HLW). The point was raised on the potential conflict between safety requirements (i.e. containing and isolating) and safeguarding (having facilities to verify stocks). However, there are potential synergies, too, it was noted, such as properly designed environmental monitoring programmes that could serve both categories – safety and safeguards.

The session summary observes from the discussions, “it became clear that this topic must be further explored.”

Beyond standards and systems, it was also advocated that there is greater coordination between international organisations; while collaboration was seen to be ‘working well’, it was ventured that more cohesive alignment of organisational efforts could help maximise the best potential use of limited resources, both nationally and internationally.

In pursuit of ensuring greater comprehension, the Policy & Strategy session also raised issues around retrieval of wastes from a proposed disposal facility. From the discussions, the session summary reports, it became apparent “there is apparently not a common understanding of what retrievability really means.” Further, and perhaps consequently, there is a lack of consistency in use of related terminology, e.g. reversibility, retrievability and recoverability. Sometimes, these have been used interchangeably.

Some spotlights in Europe

In the HLW session, the progress of a number of nations was discussed, including: Finland, Sweden, the Czech Republic, France, Japan and the UK.

The Policy & Strategy session heard about the radioactive waste management programmes of France, Germany, the Russian Federation, Republic of Belarus, Slovenia, Pakistan, Australia and the US.

Spotlighting a selection of European activities:

Finland:

Finland has the world’s first geological deep repository for HLW under construction on the island of Olkiluoto. This success follows years of underground rock research onsite at the Onkalo laboratory, and also accompanying excavation methodology research. Posiva, the company responsible for the development, operation and management of the facility received the construction licence in late 2015 to proceed and complete the facility, which is expected to be operational by the mid-2020s, subject to licensing.

Sweden:

Sweden undertakes much R&D collaboration with Finland on final waste disposal systems, such as KSB-3, an application for which was made under the Environmental Code six years ago. The company responsible for the developments is the Swedish Nuclear Fuel and Waste Management Co (SKB). In 2014, SKB applied to extend the existing final repository (SFR) for short-lived waste, at Forsmark. For HLW, the milestones being targeted for a KBS-3 system at the deep geological disposal facility – also at Forsmark – anticipates completing design & licensing around 2020; the following decade is dedicated to construction and commissioning, enabling trial operations from early 2030s. The KBS-3 system includes encapsulating spent fuel in sealed copper canisters with an insert of cast iron, and placing them in rock- carved silos embedded in bentonite clay at depths of at least 500m.

Germany:

Germany plans to end commercial electricity generation by nuclear fission by 2022 at the latest. The latest milestone event on radioactive management was a report from the commission on storage of HLW, delivered in mid-2016, dealing with the framework and methods to select a disposal site for heat- generating waste.

The Site Selection Act was passed by government three years earlier, and the commission reviewed its proposed framework over 2014-16 in an open-to-public oversight process. The potential sites are across the country but a pick is not expected for almost 15 years, by about 2031. It is anticipated that the disposal facility could be commissioned around 2050.

Also last year, provisions were made in the Atomic Energy Act for: a single, federally-owned company with private legal status to be responsible for all final disposal projects in Germany, and which will also implement the site selection process; and an independent, National Societal Committee to ensure continuity of public engagement, participation and monitoring of the site selection process.

Separately, the federal government is converting the Konrad mine at Salzgitter to become a disposal facility for waste with negligible heat generation. The Konrad disposal facility is expected to be operational from 2022 and operate for 40 years to take up to 303,000m3 of licensed waste.

Low and medium-level waste disposal has ended at the Morsleben facility, which is to be closed and sealed.

France:

Since 2011, France has been proceeding through an industrial design development phase for its proposed deep geological repository, to be set in clay host rock and to have a reversible waste disposal concept. The powers to take forward the research were granted in 2006. The responsible organisation is the French National Radioactive Waste Management Agency (Andra).

The research was underway in earnest by the 1990s when an extensive site selection process led to the selection of the Meuse/ Haute Marne location, in 1998. Work on the underground rock laboratory at the site began in 2000, and a report in 2005 confirmed the feasibility and safety of a deep disposal option in the area. The information and data led to the 2006 Act and continuing work, including further research at the underground laboratory to refine the design of the repository – the Industrial Center for Geological Disposal (Cigeo).

Two milestones in the current efforts for Cigeo are: in 2016, the safety options dossier was produced; and, the licence application is expected to be submitted around 2018. It is anticipated that, pending licensing, construction could start around 2021 for the initial industrial pilot phase to commence after the mid-2020s.

Steps forward

In its conference conclusions, the IAEA event counters the concern of the long time it takes to build final disposal facilities with the view that it is, inherently and simply, how it is: “We have also come to the realisation that the establishment of such facilities does take a very long time.”

With the condition that “we should allow it to take as long as required while still maintaining the path forward,” the conclusions from the conference further caution against optimistic time frames as that “may equate to setting oneself up to fail.”

Considering time more widely, the extra time taken to develop geological disposal facilities is argued to be relatively small compared to even the duration of their excavation and then, with safety and safeguards, holding the wastes securely for the very long term.

The conference suggests more effort to convey the message of the meticulous, continually refining analyses and strenuous efforts towards assuring safety, while also heeding societal concerns and working through step-wise licensing processes to seek social acceptance for the concepts and potential disposal facilities.

Mixed with all these factors is aligning standards and the yet more societal dimensions when a further suggestion of the conference conclusion is considered: not solely to look at national plans in isolation but also, in parallel, “an alternative path to disposal which involves shared facilities, either on a bilateral, regional or multinational scale.”

An interesting initiative that will become engaged in different ways in these discussions, and more, is the “SITEX” initiative, possibly to be launched next year (see box, below).

Whether pursued locally, regionally or through a multi-nation approach, further clarifications are required to solidify understanding and terms on the retrievability dimensions of waste for long-term safety and safeguarding at these critical infrastructure assets.

The conference concluded, further, it would be good to follow up progress with a future event but ideally not taking another 16 years until then. But even if so, according to current schedules, the world’s first HLW disposal facility, being built currently in Finland, is anticipated will have been finished and operating for a few years by then.