Canada’s operating uranium mining companies, Cameco Corporation and Areva Resources Canada Incorporated are not only leaders in uranium production, but they also lead in the development of environmentally sus­tainable uranium mining practices. They have developed new technologies to manage uranium mill tailings and reduce environmental impacts.

The tailings management strategy is based on two principles that underlie the containment of the tailings and their potential radionuclide and heavy metal contaminants:

1. Hydraulic containment during the operational phase: The pit is main­tained in a partially dewatered state throughout the operational life of the tailings facility to create a cone of depression in the groundwater system, which results in the natural flow being directed toward the pit from every direction. Since water has to be pumped continuously from the pit, current water treatment technology results in high-quality efflu­ent suitable for discharge to surface water.

2. Passive long-term containment, using the hydraulic conductivity con­trast between the tailings and their surrounding geologic materials: Long-term environmental protection is established through control of the tailings’ geochemical and geotechnical characteristics during tailings preparation and placement. This control creates future passive physical controls for groundwater movement in the system, which will exist after the decommissioning of operational facilities.

In addition to tailings from the milling process, uranium mining results in large quantities of waste rock being produced. The segregation of these materials according to their future management requirements is now a core management strategy. Material excavated from open pits is classified into three main categories: clean waste (both overburden and waste rock), special waste (containing sub-economic mineralization) and ore.

The clean waste refers to waste materials that are benign with respect to future environmental impact, and that can be disposed of in surface stockpiles or used on-site for construction purposes. The special waste is waste rock near ore bodies. This waste is potentially problematic, because it has some halo mineralization around the ore deposit, and is therefore potentially acid-generating in some instances and/or a source of contami­nated leachates when exposed to an oxidation environment. The disposal of this special waste in mined-out pits and flooding, to cut off the oxygen supply from the atmosphere and stop oxidation reactions, is now a widely recognized solution. If the pit is not suitable for the long-term management of the risk, engineered covers present an in-situ solution to impede the interaction of oxygen and moisture with the special waste. Typically, any waste material with uranium content greater than either 300 ppm U3O8 or 0.025% (250 ppm) uranium is categorized as special waste, and all material grading greater than 0.085% uranium has been classified as ore. The cut-off grade for the mill may vary depending on market condi­tions for uranium.

All mine and mill facilities provide water treatment systems to manage contaminated water collected from their tailings’ disposal facilities, as well as water inflows collected during open pit or underground mining, and problematic seepages from waste rock piles. The treatment processes vary from continuous to batch systems, and largely rely on conventional physical settling and chemical precipitation methods found in the metal mining industry.

Owners of closed uranium mines are also required to ensure that their sites are properly decommissioned, and that they have set the standard for decommissioning uranium mine sites. In instances where remedial actions are required at uranium mine and mill tailings facilities where the owner no longer exists, the Government of Canada and provincial governments ensure that the sites are safely decommissioned through cost-sharing arrangements.

1. The applicable radionuclides to be expected in a waste drum shall be provided for each drum.

2. Waste drums shall be radiologically characterized, reporting the activ­ity of all nuclides present in the waste.

3. Radiological characterization of waste drums can be carried out by non-destructive assaying (NDA) such as a drum scanner (Fig. 20.10) or radiochemical analysis of representative sample/s taken from the drum.

4. If use of statistical sampling is considered (e. g., limited number of drums analysed from a whole population), the suggested method shall be documented, justified and presented to PDO for approval, before any such sampling and analysis would be accepted.

5. NLM has a NNR-authorized radiological characterization (NDA) method for waste drums containing gamma-emitting nuclides and waste density of less than 1 g/cc in 100-210 L plastic or metal drums.

6. Waste from generators that could be characterized by this authorized method can be accepted without the need to provide evidence of radiological characterization.

7. The characterization of any waste drum containing a mixture of gamma — and non-gamma-emitting nuclides, or pure non-gamma — emitting nuclides, or density more than 1 g/cc lies with the waste.

8. When analyses are to be based on analysis of a representative sample taken from the waste, the analysis shall be performed by an accredited laboratory and method, and samples taken according to an approved sampling plan. This plan shall provide evidence that the prescribed sampling method ensures representative sampling. Evidence of at least the following shall be provided with each waste drum:

• sample and waste mass

• traceability to calibrated scales used

• activity calculation sheet

• laboratory analysis report

• reference to approved characterization procedure.

9. Evidence of the approved characterization method shall be provided to PDO, and where applicable a copy of the approved sampling plan.

10. When none of the methods described is possible, generators could still apply to PDO for acceptance of the waste by submitting a motivation for acceptance of a best estimate of the activity in the waste package based on knowledge of the waste producing process. A formal request shall be provided where at least the following shall be provided in a report:

• unique identifiers of waste drums (numbers)

• detailed description of waste and container

• quantities, number of drums and weight

• reasons why characterization (sampling/analysis, etc.) is not possible

• detailed description of the assumptions made and justifications for the expected nuclide-specific activity in each drum

• nuclide-specify activity estimations for each drum.

Up until 2011, China ’s nuclear power was still very small compared with other major world powers and only -1.5% of the nation ’ s electricity was generated by nuclear power. China has 12 operating nuclear power units (Table 22.1), distributed along coastal areas. Plate V (between pages 448 and 449) shows the geographical distribution of nuclear power plants (NPPs) in China.

With current worldwide interest in nuclear power as a clean energy source and the technical development of waste management and disposal in China, nuclear is becoming a significant proportion of China ’s power generation. As of June 2010, the official nuclear capacity targets were 80 GWe by 2020, 200 GWe by 2030 and 400 GWe by 2050 (Fig. 22.1). The aim

is that by 2050, the nuclear electricity generated should reach around 15-25% of overall electricity generated in China, similar to other superpow­ers [1-4].

China also has 12 research reactors, 2 uranium enrichment facilities in Gansu, 3 major research facilities mainly in Beijing, and also 32 storage facilities and 2 low and intermediate level waste disposal facilities (LILW) for dealing with the waste from past military and general research reactors, as well as for covering the waste from the newly built coastal NPP. The inventory from one of the waste facilities (in Gansu Province) is given in Table 22.2 .

The recent surge in nuclear power has brought much attention to China’s overall nuclear programme and the concerns are mainly in the following areas:

• social and economic impacts of nuclear energy,

• the large capital investment required,

• reactor central control systems, including plant safety, radiation protec­tion and emergency accidents, lack of qualified trained engineers and workers, lack of advanced technology,

• uranium mine resources plus management, and, in particular,

• waste management and repository resources.

Tokai-1 NPP (GCR) is a graphite-moderated, gas-cooled reactor. Tokai-1 NPP started commercial operation in 1966. However, it has disadvantages from an economic standpoint because the carbon dioxide GCR has a rela­tively low power output for the volume of the reactor. This raises the cost of electricity generation compared with light water reactors. Tokai-1 NPP was finally shut down in 1998 after it was defuelled and all fuel elements were shipped off-site for reprocessing by 2001. The reactor area was stored in a safe condition for 10 years after final shutdown to reduce radioactivity. During safe storage, conventional facilities outside the reactor area are removed to secure a transportation route for dismantling wastes, and also to create space for new waste conditioning facilities. Starting with periph­eral equipment outside the reactor area, Tokai-1 NPP is being demolished in stages. Equipment in the reactor area will be dismantled and removed after being securely stored until radioactivity has decayed to an allowable level. Finally, the site would be able to be re-used for a new NPP. Disman­tling activities initiated in 2001 and during the first five years, conventional facilities, such as the turbine system were removed. Cartridge cooling pond (CCP) water was also drained and the CCP was cleaned up for clearance activities.

Four steam raising units (SRUs) have been removed since 2006. The SRUs are 24.7 m in height, 6.3 m in diameter and within the SRUs are radio­actively contaminated and complicated structures. Jack-down methods and a remote dismantling system were developed for workers’ safety and to minimize the extent of the contaminated areas. The SRUs are removed with the system remotely in turn from bottom while lifting them with large jacks. The system enables cutting and holding not only of the SRU body but also other internal parts of the SRUs. Figure 23.2 shows images of cutting work on the SRU. The jack-down method prevents the need to work in high places and restricts the radiation controlled area to the bottom area of the SRU.

In general, radioactive wastes generated by the other nuclear weapons states programmes are less clearly documented.

• France has not declared any plutonium to be excess. HLW from pluto­nium production has probably been vitrified along with HLW from civilian programmes.

• India has an active nuclear weapons programme (e. g., Chari, 1998). Wastes are probably treated similarly to their commercial nuclear power reactor wastes for which information is available (e. g., Rao, 2001).

• Pakistan also has an active nuclear weapons programme with explosive devices tested in May 1998 (e. g., Kerr and Nikitin, 2011). Information is available on the treatment of radioactive wastes from commercial nuclear power generation programmes (e. g., Hamodi and Iqbal, 2009) and it is likely that defence wastes are treated in a similar manner.

• China has had an active weapons programme for many years and wastes are also likely to be treated in a similar manner to commercial radioac­tive wastes (e. g., Liangjin et al., 2006).

In Germany, the regulatory framework for nuclear facilities and related radioactive waste (RAW) management is based on a hierarchy of acts, ordinances, safety rules and guidelines, and is consistent with pertinent European Law. The fundamental law governing all German nuclear facili­ties is the ‘Law Over the Peaceful Use of the Nuclear Energy and the Protection against their Dangers’ of 1959 as amended, also known as the Atomic Energy Act (Atomgesetz — AtG). In its original form, the AtG provided the basis for licensing and regulating nuclear facilities and the

Legend

d Nuclear power plant (operational)

ДІ Nuclear power plant (shut down)

♦ Centralized interim storage Research reactor interim storage U Application for interim storage facility I I Opertional interim storage facility ^Exploratory mine ^Nuclear waste repository

14.1

Map of major German nuclear installations (ZLN — Zwischen Lager Nord (Interim Storage North); dates indicate year of NPP shut down or planned shut down). Source: Provided by the German Company for the Construction and Operation of Waste Repositories (DBE), Peine, Germany.

effects of ionizing radiation as well as for the handling and disposal of nuclear wastes. However, under the coalition government elected in 1998 between the Social Democratic Party (SPD) and the Green Party, the AtG was amended, based on agreements negotiated between the federal govern­ment and the major electrical utilities, to promote the phase-out of electric­ity production from nuclear energy (AtG §1). The amendment went into effect in April 2002. A key component of the AtG, as amended, was the implementation of a lifetime cap of 2,623.31 TWh on all operating nuclear power plants, which translated to an average 32-year total operational life for the existing facilities. In December 2010 the AtG was again amended
by the then-current coalition government to increase the cap by 1,804.278 TWh, thus extending the lifetime of the 17 remaining nuclear power plants by an average of 12 years (AtG §7(1a); Annex 3), and to include the provision for land expropriation contingencies for the study and development of nuclear waste repositories, if needed (AtG §9d and 9e). The AtG further assigns regulatory responsibilities between the federal govern­ment and the German Lander (Federal States) and makes provisions for the delegation of activities to third-party entities (AtG §9a(3)).

The recent incidents involving the Daiichi Power Plant in Fukushima, Japan, following the earthquake and tsunami of 11 March 2011, resulted in a freeze on plans by the German federal government to extend nuclear power plant operating life as announced by Chancellor Merkel on 14 March 2011. On 30 May 2011, the German federal government announced plans to leave off-line the seven oldest NPPs, which were immediately powered down after the disaster. An additional reactor, which had previously been shut down for maintenance purposes, will also remain off-line. The remain­ing operational NPPs will be shut down by 2022. The corresponding changes to the AtG were ratified by the German Parliament (Bundestag) and the Federal Council (Bundesrat) and incorporated into the AtG by German Federal Law Gazette 2011 Part I No. 43. The changes to the AtG became effective as of 6 August 2011.

Independent of the phase-out of nuclear energy in Germany, ensuring human and environmental protection requires a permanent solu­tion for the RAW that has been and will continue to be generated. The disposal of these wastes in geological repositories is the only solution that ensures the protection of both humans and the environment for future generations.

Overview

The sites for remediation are:

• Old industrial sites:

о from the radium industry which flourished in the interwar period о from the production of objects for medical or daily use о from the production or the usage of radium paints for watches, clocks, military instruments

о from the production or the usage of tritium-based paints from 1960

о from the extraction of caesium from monazite о from tracer fabrication (more recently) о where rehabilitation is pending

• Old laboratories dealing with radioactivity.

The top priority for the NDA in England and Wales remains the higher hazard facilities at Sellafield, especially those associated with legacy plant and historical high level wastes, and the development of a geological dis­posal facility.

Alternative disposal options for ILW have been explored and may present safe and economic facilities for use at site or national level. In addition, the current unavoidable extended storage of higher activity wastes may result in the potential for reclassification of some wastes due to radioactive decay or volume dilution arising from unavoidable dilution due to waste condi­tioning processes. This presents potential challenges to regulation of waste management practices.

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).

The Uranium Mill Tailings and Radiation Control Act (UMTRCA), which amended the AEA, directed the EPA to establish standards for active and inactive uranium and thorium mill sites. The standards for active sites, issued in 1983 as 40 CFR Part 192 (and amended in 1995), establish limits on radon emanations from tailings as well as contamination limits for build­ings, soil, and groundwater. A key aspect of UMTRCA is that it required EPA standards to address nonradiological contaminants in a manner con­sistent with EPA requirements for managing chemically hazardous waste.

The AEA does not identify uranium-mining overburden as radioactive material to be controlled, and neither the NRC nor the DOE regulate the disposition of conventional mining wastes as part of the nuclear fuel cycle. Once uranium mining product is processed or is brought into the milling circuit, including production from in-situ recovery operations, the NRC and Agreement States regulate its possession, use, transport, etc.