The logical consequence of the age of the sites and their predominantly urban characteristic (the Paris area is the historic cradle of the radium industry) is that sites have usually been reused for other purposes, including for housing. As a result, the current owners cannot be treated as responsible for the pollution that affects them. These occupied sites are in fact consid­ered as ‘assimilated to orphans’ sites, although they have an owner present. This question raises starkly the two questions of health during the works and inheritance aspects for the management of these sites, aspects that have been neglected in the past.

ANDRA personnel are used to (and are chosen for their ability to) incorporate these aspects in their delicate human relations with residents. However, any difficulties or particular relational situations (and issues potentially difficult to live with) should immediately be shared with man­agement to find adequate answers so that no added burden is put on the personnel involved. In any case, it is important to remain aware of the psychological and social dimension of the remediation of these sites.

Nuclear licensed sites in Scotland have to comply with the terms of their site licences which are granted by the ONR which reports to the UK gov­ernment. There is uniformity of approach to licensing and regulation across all UK licensed sites. ONR has responsibility for regulation of nuclear safety (Nuclear Installations Inspectorate, NII), nuclear materials transport (Department for Transport, DfT) and security (Office for Civil Nuclear Security, OCNS). On the particular subject of radioactive waste, ONR is the lead regulator for the topics of management strategy, accumulations of waste, treatment, transport and storage. The implementation of the waste hierarchy, authorisations for disposals and movements of nuclear materials are, however, regulated by SEPA which reports to the Scottish government. The waste hierarchy requires all waste managers to consider managing waste by prevention, re-use, recycling, other recovery and disposal in that order of preference. In practice, ONR and SEPA have memoranda of understanding for identifying areas where both may have an interest and for identifying which regulator will assume lead regulator status.

M. REGALBUTO, Argonne N ational Laboratory, USA and J. JONES and S. P. SCHNEIDER, US Department of Energy, USA

DOI: 10.1533/9780857097446.2.567

Abstract: The federal government of the United States is responsible for the safe disposal of spent nuclear fuel and high-level radioactive waste. The development of policies and practices has evolved over the years to ensure that the waste is managed appropriately. The major agency involved in the implementation of these activities is the Department of Energy (DOE), and the regulatory authority is assigned to the Nuclear Regulatory Commission (NRC) and Environmental Protection Agency (EPA). The US waste classification system is divided into two areas — commercial and government owned. Current storage and disposal techniques are described, addressing the different types of waste. The cleanup history and current strategies for these waste types are discussed in detail to provide the reader with an overall understanding of the US national waste management system.

Key words: radioactive waste, regulations, Department of Energy (DOE), Nuclear Regulatory Commission (NRC), low-level waste (LLW), high-level waste (HLW), mixed waste, spent fuel, storage, disposal, transuranic (TRU) waste, uranium mines and mills, Waste Isolation Pilot Plant (WIPP) , cleanup program

18.1 Introduction

The United States operates waste storage facilities for low-level waste (LLW) and transuranic (TRU) waste. It is the only country in the world that has successfully licensed, constructed, and now operates a deep geo­logical repository for defense-generated radioactive waste (RAW), the Waste Isolation Pilot Plant (WIPP). There are three main sources of nuclear

Note: The submitted manuscript has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (‘Argonne’). Argonne, a US Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC0206CHH357. The US Govern­ment retains for itself, and others acting on its behalf, a paid-up nonexclusive, irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the Government.

567

waste in the United States that resulted from either defense or civilian applications:

1. Legacy waste from military operations — defense waste was the first type of radioactive waste generated. It is the byproduct of nuclear weapons production. Legacy waste from defense applications includes materials of multiple compositions and forms, presenting challenges for stabiliza­tion before disposal. In general, the management of legacy waste con­sists of a highly integrated operation that involves storing liquid waste in underground tanks; removing, treating, and dispositioning the low — activity fraction in concrete vaults; and vitrifying and storing the higher — activity waste until permanent disposal at a federal repository. There are 88 million gallons of liquid waste stored in tanks, 1.5 million m3 of solids, and a variety of contaminated equipment. In addition, there are surplus weapons materials and spent nuclear fuel (SNF) from reactors on naval vessels.

2. Fuel cycle operations for energy production — civilian waste that results from fuel cycle stages for electricity production. This waste is the byprod­uct of facilities used for:

• uranium mining and milling — waste consists mainly of sandy tailings whose composition is the same as uranium ore (absent uranium)

• conversion, enrichment, and fuel manufacturing — the main byprod­uct is depleted uranium (DU) stored as either UF6 or U3O8

• electricity generation — the main waste in terms of activity is spent fuel, which consists of highly radioactive fission products and transu­ranic elements, and is classified as high-level waste (HLW). Nuclear wastes resulting from these operations are stable, unlike defense legacy waste, and may be readily stored and disposed. In addition to spent fuel, other low- and intermediate-level waste is generated from support and decommissioning operations.

3. Others types of waste — research and development, accelerators, medical, industrial, and naturally occurring. This waste composition is mainly short-lived radionuclides, usually classified as LLW, and is mainly stored onsite until it decays.

Both defense and civilian applications produced radioactive waste ranging from LLW to HLW. Defense and civilian generated waste have similar characteristics in terms of radiotoxicity and need to be isolated from the public; however, their forms are significantly different and the waste con­ditioning necessary before disposal differs significantly: [30]

• Defense waste needs to be concentrated and converted to a stable form before disposal, whereas civilian waste in the absence of reprocessing may be directly packaged, stored, and disposed.

Nuclear waste from both civilian and defense applications varies in its composition and form. In general, the nuclear waste attributes that affect humans and the environment and that determine the disposal path are chemical composition, physical form, and type of radiation. To facilitate a safe and cost effective waste disposal strategy, waste is categorized to provide guidance for its handling, transportation, storage, and ultimately final disposal. It is important to understand that how the waste is catego­rized ultimately affects how its final disposition is determined. The classifi­cation system ranges from very low-level waste (VLLW) to HLW. It varies from country to country but falls into two main types: those that are based on ‘where’ the waste was generated (i. e., point of origin) and those that are based on the ‘intrinsic qualities’ (i. e., risk-based parameters) of the material. The United States adopted a point of origin system, whereas the interna­tional community uses a risk-based system.

This chapter describes the current radioactive waste (RAW) manage­ment programs in the United States. The distinct policies, practices, and regulatory standards are explained, as well as the unique US waste classi­fication system used. Strategies for implementing the RAW management programs are explained for different currently existing US facilities. Multi­ple US storage and disposal facilities contain various defense and commer­cial RAW (Fig. 18.1) , which are discussed later in the chapter. The last

sections address the cleanup and closure process for specific US radioactive waste facilities, and the lessons learned from past experiences.

The DOE and its predecessor agencies generated liquid radioactive waste as a byproduct of processing SNF for the production of nuclear weapons (DOE, 2009). These wastes were stored in large underground tanks at the

Hanford site, SRS, INL, and the West Valley Demonstration Project (WVDP) in New York State. The DOE Office of Environmental Manage­ment (EM) is now safely storing 333 million L (88 million gallons) of tank waste in 229 underground tanks at three sites:

1. Hanford: 204 million L (54 million gallons) in 177 tanks

2. SRS: 125 million L (33.1 million gallons) in 49 tanks

3. INL: 3.4 million L (0.9 million gallons) in three tanks.

Tank waste is by far the DOE’s most significant environmental, safety, and health challenge, as well as the largest cost element of the cleanup program. Many of these underground tanks, particularly at Hanford, have exceeded their design lives. The DOE expends significant resources and attention to monitoring and maintaining the tanks to ensure they are sound and leak free and that workers can safely perform the necessary tank maintenance and remediation.

The unique and hazardous nature of liquid RAW requires development of innovative technologies for waste retrieval and disposition. These include constructing treatment plants to convert liquid waste into a stable, long — lasting waste form such as glass until it can be safely disposed of in a geo­logical repository. These treatment plants house highly complex chemical and physical treatment processes and must be very robust to operate safely over many years and to protect workers from radiation fields and contami­nation. Thus, they are expensive to construct and operate and require advanced engineering and technologies.

The strategy for dealing with DOE’s tank waste is to:

• minimize the volume of high-activity waste to be solidified through treatment

• store glass canisters onsite until a federal repository is ready for perma­nent disposal

• solidify the low-activity waste (LAW) fraction and dispose onsite

• develop approaches to manage/treat/dispose of some tank wastes as other than HAW

• continue emptying and closing tanks according to compliance agreements.

W. C. M. H. MEYER, G. R. LIEBENBERG and B. VD L. NEL, South African Nuclear Energy Corporation (Necsa), South Africa

DOI: 10.1533/9780857097446.2.636

Abstract: This chapter describes the development of radioactive waste (RAW) management policies in South Africa and the implementation of such policies during contaminated site clean-up.

Key words: nuclear fuel cycle, nuclear waste, waste management, waste classification, nuclear reactor programme decommissioning.

20.1 Introduction

The main generators of solid radioactive waste (SRAW) in South Africa are the South African Nuclear Engergy Corporation (Necsa), Koeberg Nuclear Power Plant (NPP) and the mining industry. The other generators such as the iThemba Accelerator facilities, hospitals and industries are regarded as minor contributors (Fig. 20.1).

The South African nuclear programme of the 1970s to mid-1990s (mainly practiced at Necsa) has left the country with liabilities with regard to redun­dant, radioactively contaminated equipment, buildings and radioactive waste (RAW). RAW management policy in South Africa is structured and implemented by including the applicable sections from the various National Acts, i. e. National Environmental Management Act (No. 107 of 1998), The National Nuclear Regulator Act (No. 47 of 1999), the Nuclear Energy Act (No. 46 of 1999), the Hazardous Substances Act (No. 15 of 1973), and the National Water Act (No. 36 of 1998).

Radioactive wastes in South Africa are divided into two categories: his­torical waste and current/future waste. Historical radioactive waste, the main producer of which was Necsa, was generated prior to 1987. Necsa (South African Nuclear Energy Corporation) is a multi-facility nuclear site that operates or has operated the processes involved in the front-end of the nuclear fuel cycle (NFC) and therefore excludes the reprocessing of spent fuel (SF). The South African nuclear programme started in 1948 and focused on research and development in the NFC and in military applications. Some highlights in the history of Necsa are the successful separation of uranium

NORTHERN

PROVINCE

Pietersburg

20.1 Locality map of South Africa showing Vaalputs, Koeberg and Pelindaba [1].

isotopes and the start of the uranium enrichment programme that included the uranium conversion facility (Fig. 20.2). The enriched uranium was used as fuel for the SAFARI-1 research reactor, the NPP at Koeberg and for military purposes.

The uranium conversion and enrichment research and production projects were terminated in the early 1990s, due to cost considerations. As stated above, the South African nuclear programme of the 1970s to mid — 1990s has left the country with liabilities with regard to redundant, radio­actively contaminated equipment and buildings and RAW. Necsa has been generating RAW since the commissioning of the SAFARI-I research reactor in 1965, and the waste includes fuel fabrication waste as well as uranium conversion and enrichment historical waste.

The bulk of Necsa ’s waste was, however, generated between 1970 and 1998 by the nuclear fuel production cycle, namely the uranium conversion, enrichment and fuel fabrication plants. The medical isotope production centre, the hot cell facilities, laboratories, decontamination facilities, etc., have also contributed significantly to the waste quantities. Necsa also accepted industrial and medical radioactive waste from smaller waste pro­ducers in the nuclear industry and the medical sector.

The bulk of Necsa ’s radioactive waste (intermediate-level waste, ILW, and high-level waste, HLW) is currently stored in various interim storage

facilities on the Necsa site (Fig. 20.3). These wastes are mostly contained in metal and concrete storage containers. The waste in containers varies widely in type (powders, filters, oil, etc.) and only ILW is encapsulated into a cement waste form. These wastes can be regarded as historical waste in that they were produced in the absence of a well-defined end-point (repository) and therefore in the absence of formal waste acceptance criteria.

The main generators of current/future SRAW in South Africa are Necsa, Koeberg power plant and the mining industry. The other generators such as the iThemba accelerator facilities, hospitals and industries are regarded as minor contributors. Koeberg generates low — and intermediate-level waste (LILW) and ILW that is sent to the national waste disposal site called Vaalputs, situated in the Northern Cape (Fig. 20.4). Koeberg also generates HLW. Currently, all the HLW (SF) is stored in the SF pool at Koeberg (Fig. 20.5). Dry storage of HLW (SF) at Vaalputs as an interim solution could be considered.

Current and future nuclear activities at Necsa will continue producing operational radioactive waste, albeit in a more controlled manner to comply with formally defined waste acceptance criteria [ 2]. Current activities at Necsa that generates waste are:

1. Nuclear fuel cycle

• Uranium conversion (future)

• Uranium enrichment (future)

• Fuel fabrication (future)

• Fuel reprocessing (future)

• Decommissioning (current and future)

• SAFARI (current materials test reactor (MTR) in South Africa)

2. Supporting facilities

• Laboratories

• Research and development

• Hot cells

• Maintenance

3. Current operations

• SAFARI 1 (research reactor)

• Nuclear technology products (NTP — production of radionuclides)

• Target plate manufacturing

4. External

• Health care waste

• Industrial waste

• Spent sealed radioactive sources

5. Decommissioning waste

• The research reactor utilized in the process for the generation of radioactive isotopes for industrial and medical applications

• The liquid waste treatment facility producing sediment that is con­ditioned and classed as SRAW

• Research laboratories

• Fuel and target plate manufacturing centre

• Decontamination facility

• Various decommissioning projects.

The Radioactive Waste Management Policy and Strategy [3] for the Republic of South Africa was approved by cabinet in November 2005, in which certain structures are to be established:

• National Committee on Radioactive Waste Management (NCRWM),

• Radioactive Waste Management Institute, and

• Radioactive Waste Fund

On a strategic level, the National Radioactive Waste Management Policy and Strategy (NRWMPS) expresses the national commitment towards the management of RAW in order to ensure a coordinated and cooperative approach to RAW management and to provide a national strategy and framework for the development of future waste management plans. Legisla­tion is currently being prepared to establish the National Radioactive Waste Management Agency (NRWMA) as an independent government- sponsored agency responsible for the disposal of all RAW on a national basis. This agency is expected to be in operation within the next three to five years.

The energy situation in Korea is worse than in many countries, as Korea has no viable natural energy sources and must import primary energy. In 2011, Korea imported approximately 97% of its primary energy. South Korea is the world’s No. 5 crude oil buyer and No. 2 liquefied natural gas importer and has boosted spending to acquire assets and develop oil and gas reserves, with a heavy focus so far on the Middle East and the Arctic. As a result, Korea is currently the ninth largest emitter of greenhouse gases in the world. Korea’ s greenhouse gas emission rates are increasing at the fastest rate (2.8%) in the world.

An important agenda in Korea’s energy development plan is to promote nuclear power as a strategic response in the post-fossil fuel era and as a pillar of energy security and independence. Korea mapped out its long-term energy development plan based on the 3Es — energy security, economic efficiency and environmental protection. Korea hopes to reach its long-term energy goals by

• improving energy efficiency and reducing energy consumption,

• promoting clean energy including nuclear and renewable energy to reduce dependence on fossil fuels,

• boosting the green energy industry, and

• making energy sources accessible and affordable to low-income households.

Korea’s total installed electricity generation capacity, standing at 72,491 MWe as of 2008, is projected to grow to 95,115 MWe by 2020 and further to 105,195 MWe by 2030. According to the Carbon Dioxide Information Analy­sis Center (CDIAC), Korea is the ninth highest country in carbon dioxide emissions in the period 1950-2005. USA (25%), China (10%) and Russia (8%) are the top countries in carbon dioxide emission in 1950-2005.

The Korean government is focusing its efforts on nuclear power as part of a national strategy to reduce greenhouse gas emissions and to achieve low carbon sustainable growth, Korea aspiring to become a green power country with low carbon, green growth. The national vision is to become the world’s seventh largest green power by 2020 and the fifth largest green power by 2050.

After more than 20 years of geological survey and investigation, the Beishan area was chosen as one of China ’s likely areas for its GDF for HLW/SF. Beishan, in the Gobi desert, is extremely dry and has been unchanged for millions of years. It is located in a remote area of Gansu Province in northwest China, not far from the west end of China’s Great Wall, Jia-Yu Guan (Jia-Yu Fortress). The narrow aubergine-like Gansu province is also referred to as Western River Corridor (Yellow River West Corridor), linking central China to China’s Xinjiang Autonomous Region — crossing and along the Gobi Desert through about a thousand miles linking to the west part of Asia and Eastern Europe as shown in Plate VII (between pages 448 and 449).

A thorough geological survey has been carried out at Beishan (Fig. 22.7). In August 2005, the CAEA revised the long-term HLW geological reposi­tory programme, with the objective of building China’s HLW geological repository by about 2050. China is closely monitoring the potential envi­ronmental impacts of nuclear energy for future generations, particularly where HLW/SF and geological disposal are concerned. China ’s regulator body, the SEPA, implements the activities related to radioactive waste and disposal, which have been managed by the China National Nuclear Corpo­ration (CNNC). Furthermore, China ’s HLW/SF geological disposal R&D programmes are carried out by CNNC’s research and engineering organiza­tion and led by BRIUG.

The Chinese government has approved a three-phase GDF programme:

1. Phase I: Site selection and site confirmation (2001-2020): Technical preparation, HLW disposal/repository programme started in China; geo­logical study, preliminary site characterization and evaluation: investiga­tions on surface geology, hydrogeology and geophysics with the drilling of four boreholes (BS01-04) and in-situ tests in boreholes.

2. Phase II: Underground Research Laboratory (URL) construction and in-situ tests (2010-2030): in-situ tests on EBS on backfill/buffer materi­als, radionuclide migration and use of the necessary natural analogues; mock-up tests and underground lab tests of backfill/buffer materials, together with coupled THMC tests.

3. Phase III: Repository construction (2030-2040): Construction structural design, simulation and modelling, construction and preparation of geo­logical repository engineering work.

While the granite site at Beishan is regarded as the most likely site, China is keeping its options open by also examining a potential GDF site in clay formations in Xinjiang in northwest China.

The major isotopes of plutonium in the reactor fuel are plutonium-238, 239, 240, 241, and 242, which account for as high as 1% of the total weight of the heavy elements in high burn-up fuel, and is recognized to have high priority in radiological protection. Analysis of a-radioactivity of soil samples by MEXT showed non-negligible distribution of plutonium isotopes in the environment. Despite the low concentration detected in soil, plutonium was found at some locations in the region up to several tens of km radius from the NPP, especially in the northwest direction. Plutonium is generally observed in the environment as a result of weapons testing and the Naga­saki atomic bomb. The radioactivity ratio between plutonium-238 and the sum of 239 and 240 is a fingerprint for the origin of plutonium contamina­tion in the environment. The ratio observed for the weapons testing fall-out in Japan is approximately 0.026 on average, but after the Fukushima acci­dent it ranged from 0.33 to 2.2. This proves that the observed plutonium is from the accident.

However, according to MEXT, the sum of the radioactivity concentration of plutonium-239 and 240 was from 0.6 to 3.3 Bq/m2 , and this was within the range of the background contamination by weapons fall-out, which is 17.8 Bq/m2 on average over the period from 2001 to 2010. Therefore, the radiological effect of the plutonium by this accident is considered to be within the existing effect of weapons testing fall-out. Zheng et al. [9] ana­lysed soil samples in the area from 25 km to as far as 230 km from the NPP.

They found 1.4 Bq/kg at locations about 30 km from the NPP, which is several times higher than the background. Despite its low radiological effect, the fact that plutonium, being quite a non-volatile element, was found significant distances away, suggests the need for more careful follow­up for the environmental effects of this accident.

The second change in the strategy was designed to better represent the pragmatism of an iterative modeling approach focused on quantifying and attempting to reduce uncertainty sufficient to support regulatory decisions. Multiple decision points were added between NSO and NDEP at critical steps in the overall progression of UGTA studies. Each decision represents a juncture between continuing forward in the strategy progression or looping back (iterating) through studies. For example, a decision point was added at the end of development of a flow and transport model in the second stage to assess whether the data and model results are adequate. If both are judged adequate, the studies proceed to an external peer review. If either the data or model results are judged inadequate, the studies return to additional site characterization, refined modeling studies, and sensitivity and uncertainty analysis, all essential parts of an iterative modeling cycle.

Uncertainty in UGTA studies, particularly modeling uncertainty, was also reassessed in the strategy revisions. The multiple components of uncertainty in modeling studies are divided into statistical and structural uncertainty following guidelines established in the uncertainty literature (Morgan and Henrion, 1990; Krupnick et al., 2006). Statistical uncertainty includes knowl­edge uncertainty and variability as a subset of knowledge uncertainty; struc­tural uncertainty refers to model, conceptual model, and decision and regulatory uncertainty.

Reassessment of uncertainty in UGTA studies led to changes in both the approach and output of modeling studies. Modeling under the original strategy emphasized development of a preferred model of groundwater flow and radionuclide transport. However, the external peer review of the modeling studies for Frenchman Flat (IT Corporation, 1999) concluded that a single model result did not adequately represent the full range of potential model responses. The revisions in the UGTA strategy are designed to emphasize development of multiple alternative model responses that rep­resent a spectrum of permissive combinations of model output using mul­tiple alternative models of the hydrologic conditions and geologic setting of flow and transport in the NNSS.

LLW and ILW originating from the operation of nuclear power plants, as well as from basic research, nuclear medicine and industrial applications in the former GDR was disposed of in the repurposed salt mine Bartensleben in Morsleben: the Morsleben Repository for Radioactive Wastes (Endlager fur radioaktive Abfalle Morsleben, ERAM) from 1971 until German reuni­fication (Fig. 14.5). The BfS became the licence holder upon reunification and DBE took over the operation of the facility as well as the task of designing any improvements and modifications through repository closure. After reunification, except for the period from 1991 to 1994 when emplace­ment operations were temporarily halted, disposal of low-level and medium — level radioactive waste with short-lived radionuclides continued until the Higher Administrative Court of Magdeburg issued an injunction on 25 September 1998 halting further disposal. On 12 April 2001, BfS committed to the permanent closure of the facility with no additional waste emplace­ment. During its period of operation from 1971 through 1998, a total of about 37,000 m3 of RAW, including about 6,621 spent sealed radiation sources, was disposed of in the facility (BfS, 2011g).

The licence application for permanent closure, including the closure plan and the associated environmental impact statement, was initially submitted to the licensing authority, the Ministry of Agriculture and Environment of Saxony-Anhalt (Ministerium fur Landwirtschaft und Umwelt Sachsen — Anhalt, MLU) on 13 September 2005. Revised documentation was resub­mitted for review to the MLU in January 2009. The MLU completed its

review in July 2009 and the documents were submitted for public comment from 21 October 2009 to 21 December 2009.

Pending completion of the closure licensing process, work is ongoing to stabilize non-repository portions of the former mine. Specifically, extensive former mining activities in the central portion of the salt body raised sig­nificant concerns regarding the long-term stability of the subsurface open­ings. To address these concerns, backfilling of 27 former mine chambers with saltcrete was initiated on 8 October 2003. These operations were completed in February 2011. A total of approximately 935,000 m3 of void volume have been filled in this manner. Final closure of the repository portions will com­mence after issuance of the closure licence (BfS, 2011h).