Tucson times thirty

Thirty years ago, the US Atomic Energy Commission (precursor to today’s US Nuclear Regulatory Commission) invited experts from various universities and engineers from the nuclear community to meet with representatives of the media to discuss the management of radioactive waste, specifically problems associated with leaks from the tanks containing high-level liquid radioactive waste at the Hanford Engineering Works, Richland, Washington. There had been a lot of misinformation in the articles appearing in the press and it was considered that this meeting at a credible forum such as the University of Arizona, with professor Roy Post and his associates as organisers, would be suitable for the dissemination of balanced and correct technical information.

The meeting was such a thundering success that it was decided to repeat it the next year. That was the birth of the Waste Management (WM) meetings at Tucson, which have since been held every year (excepting 1977) in the early desert spring of Arizona. Starting modestly with an attendance of about 100 at the first meeting, the conference had grown to attract, to its thirtieth birthday this year, more than 2000 people from over 25 countries. In addition to over 600 technical presentations, the delegates could also visit the largest exhibition in the world on radioactive waste management. Over 160 companies exhibited their wares and capabilities, which included robotics, transportation, engineering, design and construction, decontamination, decommissioning and environmental remediation.

A conference newsletter recalled some of the ‘hot topics’ of 1974. It is remarkable that many of the subjects just don’t go away: licensing and criteria, disposal in salt bed formations, retrievable disposal of waste are examples. In fact, treatment technologies for the liquid wastes in the venerable tanks at Hanford – the leaking tanks which had been the subject of the first WM meeting – had practically a whole session of papers devoted to them.

PLENARY PRESENTATIONS

The challenge of the tremendous size and scope of the ongoing US Department of Energy (DoE) environmental management programme on such waste facilities was illustrated in one of the plenary session papers by Mike Hughes of Bechtel Jacob. Of the 243 liquid waste tanks to be ‘remedied’, only two had been completed by the end of 2002; decontamination and decommissioning (D&D) of 651 facilities had been achieved, there were still 3750 facilities to go; 4928 sites have been remedied, 10,374 yet to be done. The sizes of some of the facilities are daunting and represent a challenge in waste handling, packaging, transport and disposal. The U-plant and the Purex facility in Hanford have 6200m2 and 9900m2 to be cleaned up, while the mammoth K-25 plant at Oak Ridge presents all of 164,000m2 of gas diffusion plant to be cleared.

The main message of the paper Global Perspective on Nuclear Fuel Cycle and Waste Management 2004, by Arthur de Montalemenbert of Areva, was that nuclear power is an acceptable energy option in all but one of the countries in the European Union, if all waste could be safely managed. However, even the nuclear positive French public did not seem to believe that there is a safe solution to the problem of disposal of high-level waste (HLW), as illustrated in the Table. Montalemenbert spoke also of the advantages of reprocessing fuel over the alternative of disposing it directly. The closed fuel cycle with reprocessing would require only a quarter of the repository volume necessary for direct disposal.

REPOSITORIES

An innovation in this year’s conference newsletter was the inclusion of short overviews of core issues in the field of radioactive waste management. One such was a worldwide round-up of the status of waste management programmes by John Mathieson, Nirex. It was noted that nearly half of the 40 countries with significant radioactive waste have chosen geological disposal as the long-term management option. About ten countries have active siting programmes. Long-term storage is also being considered in several countries, for example in the Netherlands, where the waste management organisation COVRA opened its 100-year HLW/spent fuel storage HABOG facility in September 2003. Active site investigations or construction activities are going on at Forsmark and Oskarshamn in Sweden, Eurajoki in Finland, Bure in France, as well as in Switzerland. Site selection activities and/or dialogues are proceeding in Japan, Australia and Belgium. Options are being discussed in the UK and in Canada, while siting activities are at an early stage in India, China, Taiwan and Poland. Political or other reasons have delayed action in this area in Germany and in Spain. In the Czech Republic, South Korea and in Italy, there have been negative public reactions to waste repository siting proposals.

Another subject that just will not lie down and die seems to be multinational repositories. The five panellists on waste management issues and challenges were all pessimistic about the political feasibility of such proposals. The failure of the Pangea concept loomed large in many memories. For those who do not immediately remember, Pangea was an idea that was put forward a few years ago by an international industrial group to locate an international repository in the bedrock of the Australian outback, where all three of the qualifying factors put up by the designers seemed to be satisfied:

stable geology, stable political conditions and availability of technical competence. The Australian government made it quite clear that the country would not accept an international repository. However, proposals for international repositories continue to pop up, most recently in Stockholm, where International Atomic Energy Agency’s director general Mohamed ElBaradei put the idea on the table, much to the embarrassment of his Swedish hosts, as could be read in the next day’s newspapers. The logic of such repositories is inescapable: must a country like Estonia, with no nuclear power programme, but with the defuelled hulks of two ex-Soviet nuclear submarine reactors on their hands, go through the entire complicated processes of siting, building, filling and sealing a repository by itself? The Krsko reactor is jointly owned by Croatia and Slovenia. Would it not be appropriate to have a joint repository? An interesting viewpoint at this panel session was from a member of the audience: if a European Federation becomes a reality, would the question of international repositories become a moot issue?

The most discussed repository at WM’04 was of course the one at Yucca Mountain. USA has already a repository for high level waste: the Waste Isolation Pilot Project (WIPP) in New Mexico. WIPP is, however, exclusively for transuranic waste from the defence programme. As early as 1989, an agreement was signed between the (then equivalent to) DoE and the owners of commercial nuclear power plants, whereby DoE undertook to build a repository for high-level radioactive waste (including spent fuel) from nuclear power plants. The repository would be ready to accept waste from 1998. The plants agreed to pay 0.1¢/kWh nuclear power sold into a ‘Nuclear Waste Fund’. Up to December 2002, $19.8 billion had been collected, of which $5.9 billion has been used for research and development. However, due to the lack of a repository, nuclear plants have been forced to resort to interim spent fuel storage installations (ISFSIs) to store fuel for the time being.

Part of the Nuclear Waste Fund has been used to build an ‘exploratory facility’ at Yucca Mountain in Nevada for a repository. The DoE has to procure a licence from the US Nuclear Regulatory Commission (NRC) for the repository. According to Title 10, Part 63, of the Code of Federal Regulations, the DoE has to file an application with the NRC for a licence to begin construction of a geologic repository and obtain a construction authorisation. Even midway through construction, DoE will have to update its application and request a licence to receive HLW. The consideration of each licence will include hearing requirements. The DoE is currently in the process of preparation of this licence application for a “first-of-a-kind facility using a one-of-a-kind regulation” – a description used in one of the papers at a Yucca Mountain Update session. As can easily be seen against the above background, quite a few years can be expected to pass before the ISFSIs at various plants can be dismantled and their contents shipped to Yucca Mountain.

SEALED RADIOACTIVE SOUCES

Sealed sources have been used in medicine, industry and research for over 100 years. The problems arising from their huge numbers, lack of institutional control and the residual radioactivity at the end of their lives were discussed at a paper session and a panel session at WM’04. To illustrate some of these problems: in the USA, there are some 600,000 sources with various amounts of radioactivity. Due to the small radiation risk (in their sealed condition), these are only ‘generally’ licensed, not requiring routine inspections and contacts with the regulatory authorities. This lack of supervision has resulted in many sources lost, stolen or unaccounted for. Approximately 200 sources are reported missing every year to the NRC. It is believed that this number is just the tip of an iceberg and actually a much larger number is in circulation. This picture is generally true of most of the industrial world.

Some of such sources end up as scrap metal and have been accidentally melted in steel mills, leading to considerable contamination and extremely high clean-up costs and loss of production. Two much publicised cases have been the melting of a small plutonium-238 source (less than 1g) – suspected most likely to have been in an abandoned cardiac pacemaker (itself an unregulated source) – at the Avesta Sheffield plant in the UK and that of a caesium-137 source, which was melted in the Acerinox Stainless Steel Mills in Algeciras, Spain. The latter triggered monitoring detectors in France, Italy, Switzerland, Germany and Austria, with measurements up to 1000 times the background levels. The Acerinox incident resulted in a $20 million loss in production, $3 million for clean-up and $3 million for disposal of waste.

A positive result of the Acerinox incident is that it led to the setting up in Spain of the first national control system to prevent such accidents.

EDF DECOMMISSIONING PROGRAMME

Up to the late nineties, Electricité de France (EdF) had planned to let its shutdown reactors stay in a stage 1 (SAFSTOR) status of decommissioning for about 50 years before total dismantling of the plants and free release of the sites. In 1996, the authorities, worried that such ‘interim’ solutions could easily become permanent, asked for proposals for the complete dismantling of the Brennilis EL4 reactor. These proposals were presented in 1999. Two years later, EdF went a step further and proposed the total dismantling of all its nine shutdown reactors during the next 25 years. This decision was in part due to the realisation that, while nuclear power is accepted by the French public as safe, reliable and cost effective, there were concerns regarding final dismantling and waste disposal. Moreover, EdF wanted to use the period 2000 to 2020 to build up an industrial organisation that can manage the dismantling of the current generation of PWRs to give place to new reactors. The plants to be dismantled are:

• All six gas-graphite reactors at Chinon, Bugey and St Laurent.
• Brennilis PHWR.
• Chooz A PWR.

• Creys-Malville (Superphenix) FBR.

• Storage silos at St Laurent for 2000t graphite fuel sleeves.

The decommissioning costs are estimated to be about €3 billion, 20-25% of which would be for planning and engineering, 40-45% for dismantling and 20-25% for waste management. The dismantling of the plants and the demolition of the buildings will result in 400,000t of radioactive waste, half of which are classified as very low-level waste (VLLW). A repository for such wastes is nearing completion and is expected to be significantly cheaper (per m3 of waste) than the LLW repositories at La Manche and L’Aube. The decommissioning programme envisages simplification of the regulatory procedure, for example by reducing the current three separate licences to one decommissioning licence. With this new offensive strategy, EdF hopes to demonstrate that total dismantling of reactor sites to release levels is possible on an industrial scale and that the wastes arising from decommissioning can be managed safely and economically.

SOGIN DECOMMISSIONING PROGRAMME

Another massive centrally planned reactor decommissioning programme is going on in Italy. The four ENEL-owned reactors – Garigliano BWR, Trino PWR, Latina GCR and Caorso BWR – were shut down after a national referendum and a subsequent parliamentary decision in 1987. Due to lack of decommissioning plans, funds and final repository for waste, the stage 1 (SAFSTOR) alternative was chosen.

In 1999, it was realised that the ‘nuclear’ know-how necessary for reactor decommissioning would disappear in a country where nuclear power was not used. It was therefore important to utilise the experienced personnel still at the plants. These sites were also needed for other industrial use. These factors led to a change of direction. The Italian parliament decided to ask the newly-established decommissioning company Sogin to plan for a total decommissioning of the four reactors by the year 2020. Sogin has later been given the responsibility for the decommissioning of all nuclear research facilities belonging to the ENEA energy research organisation. This programme is also to be completed within the same timeframe – by 2020.

For the execution of Sogin’s decommissioning plans, a repository for low- and intermediate-level waste is an essential. Sogin has also been given the responsibility for the design of the repository. According to the strategic plan, a site should be chosen by 2005 and the repository ready for use by 2009. The GCR fuel will be sent to BNFL in the UK for reprocessing, while the water reactor fuel will be interim-stored in Castor casks. To top up the funds started earlier by ENEL for financing the back-end of the fuel cycle (including decommissioning), the (non-nuclear) electricity that is sold in Italy is surcharged at 0.036 rcent/kWh for the reactors and 0.026 rcent/kWh for the research facilities. Italy’s decommissioning plans were outlined in NEI December 2003, p18.

CLEARANCE ISSUES

The clearance of solid materials from regulatory control is an issue of great importance to nuclear decommissioners, whose projects generate huge quantities of very low-level radioactive residual materials. The cost dimension of this issue was one of the themes of an overview paper on initiatives in the USA on clearance by Jas Devgun and Harold Peterson. In the USA, there are prescribed surface activity limits below which contaminated material may be released (NRC’s Regulatory Guide 1.86 from 1974). However, there are, as yet, no such regulations regarding volumetrically contaminated material. The authors quote the US National Academies’ report The Disposition Dilemma which came out in 2002, which estimates that the disposal costs of bulk materials (concrete and metal) from the decommissioning of US nuclear power plants could range from $4.5 to $11.7 billion, based on current costs and depending on the LLW disposal site chosen. If regulatory mechanisms were in place to release volumetrically contaminated material and slightly radioactive material could be sent to licensed landfills, the disposal costs would decrease to between $0.3 and $1 billion.

Currently, there are great inconsistencies between the various proposed release standards, especially in their application in the field. In the USA, there is the currently applied Regulatory Guide 1.86 (surface contamination), as well as the NRC Draft NUREG-1640 and the ANSI N13.12 standard, both of which suggest surface and volumetric limits based on an individual dose criterion of 10µSv/year. Also based on the same criterion of 10mSv/year are IAEA’s TECDOC-855 (1996) and the European Commission’s RP 89 (1998). A comparison of clearance levels for cobalt-60, for instance, shows that NUREG-1640 is an order of magnitude more restrictive than TECDOC-855. For surface contamination, NUREG-1640 is not consistent with either Regulatory Guide 1.86 or ANSI N13.12. For cobalt-60 again, NUREG-1640 asks for 280dpm/100cm2, while Regulatory Guide 1.86 allows up to 5000dpm/100cm2 and ANSI N13.12 up to 6000dpm/100cm2. Such inconsistencies, the authors point out, could cause major problems in the recycle and reuse of materials, for example in international commerce that involves millions of tons of steel in imports and exports.

A paper was presented by John Wiley on the first phase of a study by the US National Academies Board on Radioactive Waste Management on improving the regulation and management of low-activity radioactive wastes. It is to be noted that ‘low-activity waste’ according to the board is all radioactive waste other than spent nuclear fuel, high-level waste from chemical processing of spent fuel or transuranic wastes. The background to this study was that the board had observed that the regulations that control low-activity wastes have developed in an ad hoc manner over the last 60 years. This has resulted in a patchwork of regulations that usually reflect the origin of the waste – defence, nuclear power, non-nuclear industries, research, medicine, and so on – rather than its radiological hazard. The board pointed out that in some cases, this approach has led to overly restrictive regulations, resulting in excessive costs to the waste producers, while in other cases, wastes with greater potential risks to the public are left unregulated. The board proposed, in their Phase 1 report, a list of categorisation of essentially all low-activity wastes, focussing on their inherent radiological properties:

• Operational wastes from the nuclear utilities, other industries, medicine and research currently deposited in commercial repositories or at DoE sites.

• Slightly radioactive solid materials (SRSM) such as debris, rubble and contaminated soil from nuclear decommissioning and site remediation. These arise in very large volumes but produce very low or practically undetectable levels of radiation.

• Discrete sources: used radiation sources from industry, medical or research applications. These may be large enough to cause acute effects in humans or serious contamination accidents.

• Uranium and thorium ore processing wastes. Hazards are from uranium and thorium remains as well as from decay products, especially radium and radon.

• NORM and TENORM wastes from mining, oil and gas production and water treatment. Unlike the four earlier categories, which are federally regulated by the NRC, these are not. Regulation, if any, is by the individual states.

According to the board, the first four categories are the subject of great public attention and concern, while there is little public recognition of the hazards of NORM and TENORM wastes. The following incident is quoted as an example:

The Big Rock Point decommissioning project (BRP) had applied to the NRC for permission to deposit concrete rubble from the demolition of buildings at a municipal landfill in North Michigan. A 5 picoCurie/g (0.19Bq/g) above background was established as a release limit during the bulk scanning of the rubble. The plan was approved by the NRC and the Michigan Department of Environmental Quality (MDEQ). BRP’s efforts were fairly successful in convincing the public that the disposal would be fully protective of the environment, in spite of some reluctance in the minds of a few. The MDEQ pointed out that there were other things going into the landfill now that are more radioactive than the rubble. In fact, the coal ash used to cover the cells show a concentration in the range of 13 picoCurie/g (0.48Bq/g) of ash. Recently, the landfill operator installed portal monitors at the site, in preparation to accept the rubble. However, the alarm tripped when certain loads of oil and gas production sludges were brought to the site. These materials have been coming to the site for years.

Author Info:

Based on presentations at the Waste Management Symposium 2004 conference, held in Tucson, Arizona on 29 February to 4 March 2004. In a few cases, complementary information has been taken from papers published at the French Nuclear Energy Society (SFEN) conference ‘Decommissioning Challenges: an Industrial Reality?’, held in Avignon, France, on 23-27 November 2003. Shankar Menon, Menon Consulting AB, Fruängsgatan 25F, S-611 30 Nyköping, Sweden

Tables

Reasons why the European public believes no European country has yet disposed of the most hazardous category of radioactive waste