Owners and operators of nuclear power plants (NPPs) and other types of facilities manage the SNF and radioactive waste they generate at their facilities prior to disposal. The Department of Energy (DOE) is responsible for the disposal of SNF. US federal or state governments regulate waste disposal sites. Government custody may occur at different stages of the waste management process depending on the type of RAW and generating activity, including decommissioning activities.

Successful management of SNF and RAW requires careful integration among power or research reactors, waste generators, storage facilities, treat­ment facilities, and disposal sites, as well as their transportation interfaces. Integration is achieved through interface management, such as specified waste acceptance criteria. Acceptance requirements define the interfaces, allowing generators and disposers to have a common understanding of the waste. The United States recognizes the importance of this integration and manages the interfaces between various steps (e. g., storage, transportation, and disposal).

18.1.1 Radioactive waste policy

US national nuclear activities policy

The US government is responsible for the safe disposal of SNF and HLW. This section summarizes US policies and practices for SNF and radioactive waste management, and related nuclear activities.

The US government promotes the development of commercial nuclear power and nuclear technology for beneficial uses in medicine, industry, and research. The federal and regulatory duties for commercial and government sectors are assigned to different agencies, which are discussed later in this section.

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.

Scotland is similar to the rest of the UK in its hospitals and industries using radioactive sources for medical and industrial purposes. The use of these sources is controlled by the suppliers who in most cases are also responsible for their storage or disposal after use. There are many movements of these radioactive sources daily under controlled conditions and in authorised containers.

17.2 Conclusion

Although the volumes of radioactive waste and decommissioning activities in Scotland are small compared with the total UK liabilities, they are nev­ertheless diverse and challenging. Dounreay is the second most challenging site in the UK after Sellafield. Scottish radioactive waste managers and nuclear site operators manage their responsibilities both within UK require­ments and legislation and the Scottish government’s specific policies on RAW management. Although Scotland has significantly different approaches to some aspects of HAW management, these are not creating operating problems at present. During the next few decades of develop­ment of disposal technologies in the UK as a whole, and the Scottish gov­ernment’ s commitment to review its HAW policy every ten years, closer alignment and coordination are possible.

17.1.4 Oil and gas industry

Extensive oil and gas industrial activity takes place in the North Sea to the east and north east of Scotland. The main on-shore centre of the industry in Scotland is Aberdeen. Drilling and processing operations create waste sludges and films contaminating the drilling and processing equipment. These wastes contain naturally occurring radioactive materials (NORM). Although the levels of radioactivity (20-100 Bq/gm) are usually insufficient to cause concern to the health of workers exposed to them, or to the envi­ronment, precautions are taken to limit the build-up and accumulation of the wastes. The industry has a well-developed system of cleaning its pipe drilling strings, pipework, valves and other process equipment through the use of contractors.

The cleaning process, usually referred to as descaling, creates waste con­taining very low levels of radioactivity. This waste was routinely disposed of to sea near Aberdeen until 2011 when the licence was withdrawn. A facility was opened in October 2011 by a joint venture of SITA UK and Nuvia at Stoneyhill landfill site near Peterhead to process NORM. This facility cleans the NORM from the equipment by high pressure water jetting which is then encapsulated in cement in drums. The drums of cemented NORM are then disposed of under controlled conditions in the adjacent landfill facility which is operated by SITA UK (Sita, 2011).

Usually referred to as ‘Faslane’, this Royal Navy establishment is situated on Gare Loch off the Firth of Clyde in Argyll and Bute and near to Glasgow (Fig. 17.1). It was constructed in the 1940s and is now the principal support base for the UK’s operational nuclear submarine fleet. The volume of operational radioactive waste produced by servicing the submarines is small compared to refitting or decommissioning work carried out at Rosyth or Devonport, and based on projected operations the lifetime packaged volume of LLW to be disposed of at LLWR is 770 m3 (NDA, 2011a).

There are seven redundant nuclear submarines laid up floating at Rosyth and current operations are focused on one-year, six-year and twelve-year maintenance routines for each submarine to ensure they are kept in a safe state and that they will be in a condition suitable for their eventual decom­missioning. The strategy for decommissioning the UK ’s fleet of nuclear submarines was the subject of a consultation exercise carried out in late 2011/early 2012 (MoD, 2011). No date for deciding on the chosen strategy has been made but there are two significant conditions which will affect the decision and its timing. Firstly, decommissioning will not commence until a storage solution for the ILW arising has been agreed. This is a joint MoD and NDA programme in itself. Secondly, berthing space for laying up redun­dant submarines will be full by 2020, so if decommissioning has not started, then further berthing facilities would be required. The current favoured option in the consultation is that the seven laid up submarines at Rosyth would be decommissioned there, but none of the submarines which are operational at present would go to Rosyth for decommissioning.

In 2000, a joint MoD and Babcock project team decided that the nuclear support facilities that would become redundant in 2003 should be decom­missioned with the objective of de-licensing the nuclear site area of 0.83 ha to allow future industrial use. The first operations, which took four years, were to characterise the radioactive contamination, agree on monitoring protocols with the regulators and obtain the necessary authorisations from SEPA. For thoroughness in characterisation, retired employees were inter­viewed for their knowledge of historical discharges or spills, health physics logbooks were checked and the GPS-linked ‘Groundhog’ monitoring system was employed.

Rosyth has an active waste accumulation facility (AWAF) for storing LLW and ILW. It also has a LLLE outlet from the end of one of the dock’s piers. Monitoring of the sediments in the tidal and non-tidal basins detected no significant radioactivity.

The first phase of decommissioning and demolition of redundant facilities was undertaken by contractors and completed in 2009 with 99% recycling of non-asbestos building materials. This has led to low volumes of LLW requiring disposal at LLWR. Contaminated metals were authorised by SEPA to be sent to Studsvik AB in Sweden for treatment. 96% by weight was recyclable by Studsvik and one tonne of LLW was received back which was disposed of at the LLWR. A major facility decommissioned and demol­ished was the health physics building which contained the LLLE treatment plant. As LLLE treatment is a continuing requirement, a mobile unit has been procured.

The ILW waste from the decommissioning to date is organic ion exchange resin which is being stored in AWAF in 1.2 m3 transport container tanks. The strategy agreed with regulators and LLWR is to condition these resins in cementitious grout directly in one-third height ISO containers. The mon­olithic wasteform is LLW which is acceptable for disposal at LLWR. On this basis, the AWAF could be closed in 2016.

The lifetime packaged LLW disposed of at LLWR is estimated to be around 183 m3.

Decisions on delicensing are in abeyance awaiting the determination of the strategy on the SDP.

Rosyth is a long established naval dockyard built between 1909 and 1915. It covers 127 ha and is located on the north side of the Firth of Forth in Fife (Fig 17.1). The dockyard became involved with nuclear operations in 1960 with the start of support services to the Royal Navy’s nuclear submarines. Some support work continued until 2003 although since 1993 the main support services have been provided at Devonport in England. In 1997 the dockyard was sold to Babcock International which now holds the nuclear site licence. The nuclear decommissioning liability is still retained by the MoD.

17.1.3 Naval reactor test establishment (NRTE) Vulcan

Vulcan is situated in Caithness adjacent to the Dounreay site. The site is owned by the MoD on a long lease from the NDA and operated by Rolls Royce. Its purpose is to test nuclear submarine propulsion reactors on shore in support of the operating fleet.

Construction of the Dounreay Submarine Prototype 1 (DSMP1) was started in 1957 and the first reactor was operational in 1965. The facility tested a number of reactor cores until it was shut down in 1984. The facility includes a pond where fuel from the testing programme is stored.

A second facility, the shore test facility (STF) was commissioned in 1987 for a similar testing programme on the next generation of submarine reac­tors. It is planned to operate this facility until 2015 when it will no longer be required (UK Government, 2011) as a reactor core prototype plant. Associated with the STF is a pond where fuel from this testing programme is stored and a decontamination and waste treatment facility (DWTF) in which is stored activated organic resins from decontamination operations in the STF. Operational LLW from Vulcan is transferred to Dounreay for disposal and LLLE is transferred to the Dounreay LLLETP.

Post-operational activities and early decommissioning could start in 2015 and be completed by 2021. Options to continue support to the naval nuclear propulsion programme from the Vulcan site are being considered together with a decommissioning programme. Final decommissioning and demoli­tion could take up until 2050 to be completed. Some of this could be planned in and associated with the decommissioning programme at Doun — reay. The decommissioning waste volumes are small compared to Dounreay and could be incorporated into Dounreay’s management arrangements. The lifetime packaged volume of LLW to be disposed of at Dounreay is esti­mated to be around 3,600 m3. The lifetime packaged volume of ILW, possibly to be stored at Dounreay, is estimated to be around 156 m3 (NDA, 2011a). However, the Scottish HAW policy does not apply to Vulcan so the final end-point for this ILW may be different from that of Dounreay’s.

A wide range of unirradiated and irradiated uranium and plutonium mix­tures of fast reactor fuels has been left over from the research programme. These require a high level of security for the site and their storage arrange­ments. The NDA reviewed the credible options for this fuel which included stakeholder consultation. The top two options were continued storage at Dounreay or transfer to Sellafield. The former would require rebuilding of stores over a 100-year period and continuing high level security arrange­ments. The latter would allow use of common facilities and security at Sellafield but would entail transfers through many communities. The deci­sion to transfer the exotic fuels to Sellafield as the preferred option was made in February 2013 (NDA, 2013).