The Act of 28 June 2006 reinforced ANDRA’s mission of design and opera­tion of RAW disposal and also requested that ANDRA have a ‘public service’ mission (ANDRA, 2006):

• The Agency must develop, in the clay layer at 500 m depth in the Meuse and Haute-Marne districts, a reversible deep repository for high level and intermediate long-lived waste.

• It must also seek a solution for low-level long-lived waste, both radium­bearing and graphite.

• The ‘public service’ missions were two-fold:

— Remediation of former radioactively contaminated so-called orphan sites (i. e., those for which there is no responsible body) is managed in a more sustainable manner with the creation, as from 2007, of the National Commission for Assistance in the Radioactive Area (‘Com­mission Nationale des Aides dans le domaine Radioactif’, or CNAR), decided by the Board of ANDRA.

— The management of radioactive waste obtained from individuals (e. g., alarms with radio luminescent needles, radium fountains — radium was believed in the past to have therapeutic virtues and such fountains for radium distribution can still be found in French house­holds, etc.) was addressed with the launch in late 2008 of a campaign (involving the 36,000 mayors of France, the departmental services for fire and rescue, the waste treatment entities, among others) to identify and remove such radioactive objects from homes and manage them safely through storage or disposal.

The UK government (through the Department of Energy and Climate Change, DECC) is working with the NDA through its RWMD (a prospective
site licence company) on finding a site and implementing the construction of a GDF through the volunteer process. The variety of the UK’s wastes mean that a multi-level and chamber repository will be needed with differ­ent wastes in separate sections (Fig. 16.10; NDA, 2010).

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).

In 2009, the Obama Administration announced that it had determined that developing a repository at Yucca Mountain, Nevada, is not a workable option and that the United States needs a different solution for nuclear waste disposal. The Secretary of Energy established the BRC on America’s Nuclear Future in January 2010 to evaluate alternative approaches for managing SNF (referred to as ‘used nuclear fuel’ in BRC documents) and HLW from commercial and defense activities.

The BRC conducted a comprehensive review of policies for managing the back end of the nuclear fuel cycle. It has provided recommendations for ‘developing a safe long-term solution to managing the Nation ’s used nuclear fuel and nuclear waste.’ An interim draft report was issued in July 2011, and a final report was submitted to the Secretary of Energy in January 2012 (BRC, 2012).

The report contains eight recommendations for legislative and adminis­trative action to develop a ‘new’ strategy to manage nuclear waste:

1. A new, consent-based approach to siting future nuclear waste manage­ment facilities.

2. A new organization dedicated solely to implementing the waste man­agement program and empowered with the authority and resources to succeed.

3. Access to the funds nuclear utility ratepayers are providing for the purpose of nuclear waste management.

4. Prompt efforts to develop one or more geological disposal facilities.

5. Prompt efforts to develop one or more consolidated storage facilities.

6. Prompt efforts to prepare for the eventual large-scale transport of SNF and HLW to consolidated storage and disposal facilities when such facilities become available.

7. Support for continued US innovation in nuclear energy technology and for workforce development.

8. Active US leadership in international efforts to address safety, waste management, nonproliferation, and security concerns.

The near-term direction advocated by the BRC aligns with ongoing DOE programming and planning. Current programs will identify alternatives and conduct scientific research and technology development to enable long­term storage, transportation, and geological disposal of SNF and all radioac­tive wastes generated by existing and future nuclear fuel cycles. The BRC report has informed the Administration ’s work with Congress to define a responsible and achievable path forward to manage used nuclear fuel and nuclear waste in the United States.

In January 2013, the Secretary of Energy issued the Administration ’s Strategy for the Management and Disposal of Used Nuclear Fuel and High — Level Radioactive Waste. The strategy is a ‘framework for moving toward a sustainable program to develop an integrated system capable of transport­ing, storing, and disposing of used nuclear fuel and high-level radioactive waste from civilian nuclear power generation, defense, national security and other activities’ (DOE, 2013). It addresses several issues: it serves as an Administration policy statement for handling the disposition of nuclear waste; it presents the response to the BRC report; and it represents an initial basis for discussions among the Administration, Congress, and other stake­holders on the path forward for nuclear waste disposal.

The strategy includes a phased, adaptive, and consent-based approach to siting and implementing a comprehensive management and disposal system. With the appropriate authorizations from Congress, the Administration plans to implement a program over the next ten years that:

• sites, designs, licenses, constructs, and begins operations of a pilot interim storage facility by 2021 with an initial focus on accepting used nuclear fuel from shut-down reactor sites;

• advances toward the siting and licensing of a larger interim storage facility to be available by 2025 that will have sufficient capacity to provide flexibility in the waste management system and allow for accept­ance of enough used nuclear fuel to reduce expected government liabilities;

• makes demonstrable progress on the siting and characterization of geo­logic repository sites to facilitate the availability of a geologic repository by 2048.

The Administration, through the DOE, is undertaking activities within existing Congressional authorization to plan for the eventual transporta­tion, storage, and disposal of used nuclear fuel. Activities range from exam­ining waste management system design concepts, to developing plans for consent-based siting processes, to conducting research and development on the suitability of various geologies for a repository.

19.4.1 Low-level, historical waste projects

A variety of sites contaminated with historical low-level radioactive waste materials have been identified across Canada. The diversity of wastes, wasteforms and sites include: pitchblende ore handling facilities used during the 1930s, 1940s and 1950s along a 2,200 km transportation route between the Port Radium mine in the Northwest Territories and Fort McMurray in
northern Alberta; uranium and radium processing residues currently located in Port Hope area waste sites established during the 1930s, 1940s and 1950s; discarded luminescent dials and apparatus found at sites across Canada; and former radium dial painting and waste management operations located in the Toronto area.

As described in Section 19.2.5, the Government of Canada established the LLRWMO in 1982 to characterize and delineate these historical low — level waste sites across Canada, and undertake decontamination, waste consolidation and interim waste storage as required at these sites. The types of remedial work conducted by the LLRWMO at these historical waste sites include: excavation and transportation of radioactively contaminated soil in quantities ranging from a few m3 to thousands of m3; collection/consolida — tion of contaminated debris and radioactive artifacts; decontamination of residential and industrial structures primarily associated with historical radium dial painting operations; and the development of community-based interim waste management solutions pending the development of a longer — term solution. This work routinely involves liaison with the local communi­ties and regulatory agencies to develop acceptable waste management solutions for the short and long term (Benitez et al., 2011; Gardiner et al, 2011).

Most of the remaining historical waste to be dealt with in Canada is located along the northern transportation route. The waste has resulted from the past transport of radium and uranium-bearing ore and concen­trates from the Port Radium mine to the barge-to-rail transfer point at Fort McMurray. The sites that still have to be remediated include Sawmill Bay, Bennett Landing, Bell Rock and Fort Fitzgerald. Strategies are currently being developed for the cleanup of these remaining sites. They are esti­mated to consist of about 10,000 m3 of contaminated soils.

The process involves the implementation of the national radioactive waste classification scheme in the Necsa context in support of solid radioactive waste management on the Necsa site at Pelindaba. The system is aimed at presenting the classification scheme as it applies to Necsa and providing principles and guidance on waste classification in terms of the approved classification scheme [3] and latest international developments in this regard [15]. The system is further aimed at applying the waste classification criteria to typical waste streams at Necsa.

20.1.7 Characterization of solid radioactive waste

This provides for a system to characterize waste in terms of its radiological, physical, biological and chemical properties. It determines the needs for further adjustment, treatment, conditioning, or its suitability for further handling, processing, storage or disposal.

With the rapid development of its nuclear industry, China’s RAW manage­ment has gradually been improved over the past 20 years. In the 1950s, when the country’s nuclear industry had just begun to develop, the Chinese gov­ernment put forward the policy that radiation protection should be devel­oped before the nuclear industry became operational, which required that any work involving radioactivity must be accompanied by waste treatment capability and that any RAW discharge complies with the required stand­ards. Therefore, nuclear industry production and research facilities were all equipped with RAW treatment and storage installations for storage of dif­ferent categories of wastes in accordance with the categorization given in Table 22.4.

In the early years, the liquid and gaseous radioactive waste treatment processes, as part of nuclear production and research activities and as a component associated with the main production process, employed purifica­tion filtration, evaporation, and ion exchange among other practices. Such wastes were discharged into the atmosphere and surface water after meeting the national standards — ‘Radiation Protection Regulations’ (GBJ8-74) [11,12]. This standard was issued by the State of Ministry of Nuclear Indus­try, targeting the national regulations on the treatment and disposal of radioactive wastes. Those liquid and solid radioactive wastes that could not be discharged were stored. In general, in the process of nuclear facility construction and operation, the treatment of gaseous and liquid radioactive waste generally received due attention with practical treatment technology being employed. This played an important role in ensuring normal operation as well as environmental protection. All sorts of liquid wastes generated in the processes operating at each nuclear facility underwent solidification treatment. Evaporator residues of liquid LLW underwent bituminization and the resultant solidified forms, after packaging, were sent to a storage facility near Beijing. The programme for dealing with China’s legacy HLW is based on joule heated ceramic melters (JHCM) such as those used in Germany, Japan, the US and Russia operating at well over 1,100°C. However, opportunities exist in the future that waste streams from NPP from China may be more applicable to cold crucible induction melting (CCIM) technol­ogy, which has been developed intensively by France and Russia. From a materials point of view, selected glass compositions will be within the boro — silicate range adapted for current wastes and the envisaged future HLW streams. Large-scale research programmes and investment are also under way on the development of glass composite and ceramic waste forms.

With the construction and expansion of NPPs and the development of the radioactive waste management concepts of making safe disposal central, progress has been made in RAW treatment and conditioning technology and installation. NPPs in China now have liquid and solid RAW treatment facilities installed during their construction. NPP operators prepare RAW management programmes, which specify the assignment of responsibility for RAW management within each NPP. The Chief Manager of each nuclear operational organization acts as the primary person responsible for RAW management. The Chief Manager is responsible for providing suffi­cient resources to ensure effective implementation of the RAW manage­ment programme, and to ensure the national limits of radioactive effluents are complied with. This RAW management arrangement can be maintained and modified in a sustainable manner.

RAWs are managed according to their categories at NPPs. Based on the features of each NPP, the specific categorization schemes are developed and applied to the management of RAW arising from NPP operations. In general, concentrated liquid and spent ion exchange resins are solidified in cement, the waste arising from technology processes is held in storage after sorting and compression. Cement solidification proc­esses have been established in Daya Bay, QNPP II and Ling-ao NPPs to carry out cement solidification of liquid LILW, spent exchange resins and spent filter cartridges. Spent ion exchange resins produced at QNPP and QNPP III are currently stored temporarily and cemented waste forms are stored in waste storage facilities at such NPPs. The solid RAW gener­ated at NPPs is mainly stored in on-site facilities and the liquid wastes are stored in tanks. On the whole, the facilities for waste storage at NPPs are well constructed and in a good condition, and comply with current requirements.

In China, the NPP operators continue to carry out technology modifica­tions. QNPP upgraded the cement solidification installation and as a result the waste drum-filling coefficient increased from less than 79% to more than 90%. Guangdong Daya Bay NPP continues testing to improve the formula for cementation of its spent ion exchange resin so as to raise the waste loading capacity. Daily operational practices include measures to control waste generation. Personnel awareness of waste minimization is reinforced through training and education activities. Suitable operational processes are employed and technological and administrative measures are envisaged to make waste generation ALARA. Moreover, detailed work plans and arrangements to control waste generation during maintenance include: [37]

• enhanced recovery and re-use by dismantling the disused intermediate and high efficiency filters, and returning metal frameworks to manufac­turers when the contamination is below clearance levels.

As of December 2006, the volume of solid LILW generated from China’s NPPs was 4773 m3.

Tracking solid RAW is an important aspect in its safety RAW manage­ment. Each NPP writes specific management procedures to require the tracking of its RAW. Each waste package is tracked by establishing a unique RAW record. The relevant information of the record includes origin of waste, type of waste, date of waste generation, radioactivity level in waste, quantity/volume of waste, temporary storage location, etc.

A main objective of RAW management is to minimize the generation of RAW in China. Compared with some countries, there is still potential to reduce waste generated at China’s NPPs. However, the minimization of RAW is a combined effort balancing factors of technology, safety and economy. China is taking additional actions in controlling the generation of the wastes, upgrading management practices, introducing advanced waste reduction technologies, promoting specialization and socialization in RAW treatment services.

The sequences of events in the reactor accident were as follows:

1. Fukushima was shaken by an earthquake measuring magnitude 9.0 on the Richter scale; however, the six NPPs were designed on the basis of an earthquake equivalent to magnitude 8.2.

2. The three units in operation, units 1, 2 and 3, automatically went into SCRAM (sudden shutting down of a nuclear reactor, usually by rapid insertion of control rods), which was triggered by detecting the high earthquake acceleration. Following the total loss of off-site power, emer­gency power generators automatically started to supply electricity.

3. The standard post-shutdown cooling modes started up to remove the decay heat. This residual heat must be removed to prevent the nuclear fuel, mainly UO2 , cladding metal, and supporting structural elements from melting in the core of the reactor. The melting point of UO2 is approximately 2,900°C, while those of cladding and supporting parts are in the range of 1,300-1800°C.

4. About 45 minutes after the earthquake, tsunami waves variously hit the units, destroying seawater pumps for the residual heat removal system and many of the emergency generators. Eventually, this lead to the total loss of the electricity that powered the water pumps used to maintain cooling water circulation around the reactor cores. The spent fuel (SF) storage pools suffered the same problem.

5. In spite of the performance of various emergency core cooling systems, as well as trials to vent the reactor vessel enabling water injection from outside, the core eventually became uncovered by cooling water. Along with the increase in temperature of the uncovered fuel, the reaction of cladding material with steam to generate hydrogen proceeded rapidly, and the fuel started melting leading to core destruction through meltdown.

6. According to the results of the simulation calculation conducted even with insufficient records of the instrumentation, most of the core is believed to have melted in unit 1. In units 2 and 3, much of the fuel apparently melted but to a lesser extent than in unit 1 and dropped to the bottom of the pressure vessel. It is considered that a certain part of the fused fuels and structural materials flowed out from the reactor pressure vessels (RPVs) into the primary containment vessels (PCVs).

7. During the severe accident process, appreciable amounts of volatile radionuclides (typically these are noble gases, cesium and iodine) are considered to have evaporated. They must have escaped from the RPV into the PCVs, and finally escaped via cracks or openings made under the severe conditions.

8. Hydrogen explosions occurred in units 1, 3 and 4, and these seriously damaged their operation floors at the top of the reactor building, and also the upper side walls of unit 4.

The following sections briefly describe the hydrogeological setting by cor­rection action units (CAUs) of geographical areas used for underground testing on the NNSS (Fig. 26.3).

26.3.1 Frenchman Flat CAU

Ten underground detonations were conducted in Frenchman Flat (Figs 26.3 and 26.4), a strike-slip pull-apart basin formed at the northeastern termina­tion of the Rock Valley fault (Bechtel, Nevada (BN), 2005). Seven tests were detonated in the northern part of the basin in the lower part of the unsatu­rated zone in alluvium and distal facies of the volcanic rocks originating from eruptive centers in the volcanic highland to the northwest. Three tests were conducted in alluvium in central Frenchman Flat; two of the tests are in the unsaturated zone and one test was detonated below the water table (NNES, 2010a). Local directions of groundwater flow in the Frenchman Flat basin are difficult to establish because of low hydrologic gradients in the basin. Flow is inferred to be predominantly to the southeast driven by higher groundwater levels northwest of Frenchman Flat across the north­east trending, right-slip Cane Spring fault (NNES, 2010a) (Fig. 26.4). Groundwater velocities are very low (1 meter per year or less) down gradi­ent of nuclear tests conducted in alluvium (high porosity alluvial aquifer) in central and northern Frenchman Flat, but may be higher down gradient of two tests where flow is in fractured volcanic aquifers (welded tuff and basalt lava; SNJV, 2006; NNES, 2010a). Gradients in the alluvial and vol­canic aquifers are downward but flow from these sections into the underly­ing carbonate aquifer is limited across a basal confining unit of zeolitized volcanic rocks.

The POLLUX® was specifically developed for the geological disposal of SNF, but is also suitable for interim storage and transportation if required. A single POLLUX® can hold ten irradiated fuel rods from a PWR or 30 fuel rods from a BWR. It has a diameter of 1.6 m, a length of approximately 5.5 m, and a weight of 65 tonnes when loaded. The container is a double­shell design with an internal container to accommodate the fuel rods from

SNF assemblies, which are separated by a neutron moderator, and an exter­nal shield container made of spheroidal graphite (SG) iron (GNS, 2011b ; Diersch et al, 1993). Figure 14.3 shows a POLLUX® container being hoisted into place for a 9 m edge-on drop test.