Raffinate from reprocessing DFR and PFR fuel is also stored in dedicated tanks in the same underground lined and shielded vaults as the research fuel raffinate. In this case, though, there is not yet a facility at Dounreay to treat and encapsulate this particular raffinate.

Gaseous LLW

All operational facilities at Dounreay have general space extraction and fresh air ingress ventilation systems and, if necessary, dedicated systems for contained active equipment ventilation. The latter is usually associated with gloveboxes, shielded cells and transfer systems. The extracted air is filtered and monitored before discharge to atmosphere under an authorisation from SEPA. There are a number of individual discharge stacks for specific facilities, but the fuel cycle area is served by an integrated system installed in 2010 to provide active ventilation requirements for both the current operations and the decommissioning of the complex and interconnected fuel cycle plants and laboratories (IMechE, 2010).

Low-level waste

Commercial and government facilities exist for LLW processing, including treatment, conditioning, and disposal. Generators prepare LLW for ship­ment to licensed disposal facilities. Commercial LLW disposal facilities are designed, constructed, and operated under licenses issued by either the NRC or an Agreement State, based on NRC health and safety regulations governing waste disposal quantities, forms, and activity levels. The DOE operates disposal facilities for LLW that it owns or generates and uses com­mercial LLW disposal sites in certain circumstances.

LLW is disposed of in near-surface facilities, i. e. a land disposal facility in which radioactive waste is disposed of in or within the upper 30 m of the Earth’s surface. Currently, commercial generators of Class B and C wastes in 36 states do not have access to a disposal site for these wastes, which are being stored pending a disposal pathway.

Greater-than-class C LLW

Greater-than-class C (GTCC) LLW waste is a form of LLW containing long — and short-lived radionuclides with properties requiring a more robust disposal strategy than for other classes of LLW. In the context of this chapter, ‘more robust’ means a greater degree of isolation, durability, and performance than is associated with near-surface disposal for other classes of LLW. This could include intermediate-level waste, as defined by some nations. The authority to possess this type of radioactive material is included in NRC or Agreement State licenses.

GTCC LLW may generally be grouped into the following three types: sealed sources, activated metals, and other waste. Other GTCC LLW includes contaminated equipment, trash, and scrap metal from miscellane­ous industrial activities, such as manufacturing of sealed sources and laboratory research. Most GTCC LLW is activated metal, generated by decommissioning NPPs, and disused sealed sources. Although the US inven­tory of GTCC LLW is modest, the construction of new commercial reactors and other proposed actions could generate additional quantities of GTCC LLW. GTCC LLW is stored until an adequate method of disposal is estab­lished by the DOE.

The owners of low — and intermediate-level radioactive waste are managing and operating storage facilities for their wastes. In addition, the two major waste owners, OPG and AECL, are pursuing initiatives to develop and implement long-term management solutions.

Segregation of waste

Unconditioned waste shall be segregated as follows:

1. compressible waste

2. non-compressible waste

3. uranium contaminated steel and metal waste (excluding lead), which shall be segregated in the following sub-groups:

• mild steel

• galvanized steel

• stainless steel

• aluminium and

• copper.

Low and intermediate level radioactive waste (LILW) arises mainly from NPP operation and nuclear technology applications. Radioactive waste pro­duced from operating NPPs is principally from the following:

• main process equipment and waste treatment equipment, including sec­ondary waste from loop leakage or drainage and waste treatment systems, which includes airborne and liquid radioactive wastes,

• technical maintenance during operation,

• protective articles such as shielding, equipment and miscellaneous scrap replaced during the daily operation.

Table 22.4 Disposal-based radioactive waste categorization system

Waste category Disposal approach

The wastes arising from nuclear technology applications refers to con­taminants that arise from the applications of radioisotopes and irradiation technology in industry, agriculture, medicine, research and teaching, which contain:

• man-made radionuclides with specific activity higher than 2 x 104 Bq/kg;

• or NORM wastes with specific activity higher than 7.4 x 104 Bq/kg;

• or abandoned/discarded wastes arising from the above-mentioned activ­ities with surface contamination levels exceeding the regulatory limits.

Such LILW is widely distributed, of a wide variety, and usually in small amounts.

The plutonium fuel fabrication facility (PFFF) operated from 1972 to 2002 for fabricating MOX fuels for Fugen and the experimental Joyo fast breeder reactor (FBR). The decommissioning and dismantling (D&D) project for the PFFF is divided into the following four phases:

• Phase 1 (up to 2010): stabilization and shipment of nuclear material in the facility. Choose decontamination and volume reduction techniques.

• Phase 2 (2010-2015): D&D planning and adaptability tests.

• Phase 3 (2015-2020): size reduction of equipment and glove box. R&D programme carried out.

• Phase 4 (2020-2035): re-use of buildings for waste storage.

An issue relating to the accumulation of special nuclear material became apparent in the 1990s in this facility. Eight glove boxes in the facility had to be replaced by those with an improved automated fuel fabrication system and residuals recovery system. In order to dismantle these glove boxes, it was necessary to have a more durable containment structure than that of the plastic enclosure, commonly used at the time. To circumvent these issues, the glove box dismantling facility, a centralized decommissioning workshop to dismantle glove boxes, was developed. The purpose of the workshop is to safely dismantle the after-service glove boxes and recover the fuel residuals from the glove boxes. The basic concepts of the workshop are as follows:

1. The workshop has the functionality of a glove box. To prevent the spread of contamination, the level of the internal pressure is kept around 300 Pa in gauge pressure negative to the surrounding room pressure.

2. The workshop is installed in a room in the basement of the plutonium fuel production facility (PFPF) and used for glove box dismantling repeatedly.

3. Remote-controlled devices are installed in the workshop to reduce the radiation dose to which workers are exposed.

The activity undertaken was of both remote and hands-on type size reduc­tion. The data and knowledge will be reflected in the planning of the D&D project for PFFF.

Technological developments to reduce secondary waste generation are being carried out. Dismantled equipment is cut and wrapped in plastic sheets and packing tape, and stored in 200 L drums. The amount of packag­ing material (secondary waste) sheets may be about 20% of the volume of dismantled materials. In addition, the packaging activities are performed by workers wearing airline suits. These suits are also secondary wastes. In addi­tion, waste treatment facilities will remove the packaging materials from the dismantled equipment which must then be sorted.

To reduce waste treatment work and the amount of secondary waste, a direct in-drum system for RAW management has been developed. The direct in-drum system can be stored directly in a double-skin drum without packaging. In addition, RAW stored in the drums can easily be retrieved

from them. To prevent the leakage of radioactivity during storage and retrieval of RAW, the lid of the double-skin drum and of the direct in-drum system are connected by a gasket. The direct in-drum system (Fig. 23.3) is attached to the glove to

The NNSS is located in the Great Basin portion of the basin-range physi­ographic province of the southwestern United States (Hunt, 1967; Stewart, 1980), approximately 150 km east of the Sierra Nevada mountain range containing the highest point in the contiguous United States (Mount Whitney, 4421 m) and about 40 km northeast of Death Valley, the lowest

point in North America (86 meters below sea level) (see Fig. 26.1). There are multiple definitions of the Great Basin based on hydrographic, physi­ographic, and floristic criteria (Grayson, 1993), but the most useful defini­tion for this chapter is the hydrographic definition. The Great Basin is an area centered about the state of Nevada, and including parts of the states of California, Utah, Oregon, and Idaho of the western United States that are internally drained. Precipitation in the Great Basin has no ocean outlet

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26.1 Shaded relief map of Southern Nevada, and adjacent areas of California in the southwestern United States. The solid line denotes the boundary of the Nevada National Security Site (NNSS; formerly the Nevada Test Site). The dashed line is the boundary of the Death Valley regional flow system (DVRFS) after Belcher and Sweetkind (2010). Death Valley and the Amargosa Desert are major discharge areas for the DVRFS.

and surface drainage flows into ephemeral streams that empty into saline lakes or dissipate through combined evaporation, transpiration and/or infiltration. Groundwater flow is an important component of the regional water budget and the NNSS is located in the central part of the Death Valley regional flow system (DVRFS; Winograd and Thordarson, 1975; D’Agnese et al., 1997; Belcher et al., 2004), a large internally drained area of Nevada (Fig. 26.1). Recharge in the DVRFS occurs primarily at higher elevation mountain ranges in the north, east and southern parts of the flow system. Discharge areas are distributed in the lower elevations of the Amar — gosa Desert and ultimately Death Valley (Fig. 26.1). The climate of the region is arid and is controlled largely by the rain shadow of the Sierra Nevada mountain range to the west with local variations controlled by elevation.

The hydrology of the NNSS is controlled primarily by three hydrologic and geological features. The first is the underflow of groundwater in the DVRFS and the location of areas of significant local recharge in the NNSS at the higher elevation mountain ranges and mesas of the site. The second feature is the physical properties and spatial distribution of diverse assem­blages of rock lithologies that form the aquifers and aquitards for the groundwater flow system. These rocks comprise three major lithologically and temporally distinct groups including Paleozoic carbonates and clastic sedimentary rocks, Miocene volcanic rocks erupted from multiple coalesced caldera centers, and thick alluvium deposited in fault-controlled basins. The third feature is the location and nature of major structural and tectonic features, including regional thrust belts formed in late Paleozoic and Meso­zoic time, major structures associated with caldera collapse and resurgence, and Miocene and younger extensional and strike-slip faults that formed the alluvial basins of the eastern and southern areas of the NNSS. This combi­nation of features control the volume, velocity and direction of groundwater flow and resulting transport of testing-introduced radionuclides.

Germany currently operates a once-through fuel cycle. Although initial intentions were for a closed fuel cycle, strong public opposition and eco­nomic concerns led to the abandonment of plans for a reprocessing facility in the Bavarian town of Wackersdorf in 1988. Until 1994 utilities were obliged to reprocess SNF in order to recover usable materials for recycling into new fuel assemblies. However, because Germany never fully developed the capability, most of the reprocessing of SNF was contracted to facilities in France and the United Kingdom. Only a small amount of fuel was reprocessed in Germany at the Karlsruhe reprocessing plant (Wiederauf — arbeitungsanlage Karlsruhe, WAK). Between the commissioning of the WAK in 1971 and its shut-down in 1990, about 200 tonnes of irradiated fuel were reprocessed at the facility (EWN Gruppe, 2010). Federal policies began to change between 1994 and 1998 when both reprocessing and direct disposal were equally acceptable to the government. As part of the agree­ment negotiated between the SPD-Green coalition federal government and the nuclear utilities, it was agreed in 2001 that SNF would be disposed of directly and foreign shipments for reprocessing SNF would no longer be allowed after mid-2005 (subsequently codified into the AtG §9a).

As of 31 December 2010, 97 casks of type CASTOR® HAW 20/28 CG or similar with vitrified HLW were being stored at the interim storage facility for heat-generating waste at Gorleben. An additional 33 casks of vitrified HLW will be shipped from France and the United Kingdom associated with reprocessing of German SNF (BfS, 2011c). Eleven of the casks were returned from the French reprocessing facility in La Hague by the end of 2011 and 21 will be returned from the reprocessing facility at Sellafield in the United Kingdom by the end of 2017. By contractual accord, LLW and ILW gener­ated as a by-product of reprocessing will remain at the foreign facilities. As an offset, approximately 5% additional canisters with vitrified HLW are included in the waste being returned to Germany for final disposal. Addi­tionally, by the end of 2024, the final shipment of approximately 150 CASTOR®-type casks containing high-pressure compacted waste will be returned to Germany from La Hague.

If might be intellectually satisfying to seek total clean-up, but experience shows that this goal is often illusory and generates unnecessary costs. Indeed, what does total clean-up mean? Should we seek to return to the background noise level, regardless of the cost incurred? The house in Gif — sur-Yvette shows that even having reached a dose rate for Ra-226 in the range of background noise (0.1 mSv/h) in the home, radon levels remain significant and close to the pseudo-limit of 400 Bq/m3. Substantial resources have been committed without the possibility of cleaning the house completely, simply because working on the house itself without addressing the surrounding land amounted to moving the pollution limit without elimi­nating it (radon, in its migration in the ground, ignores administrative boundaries). Total clean-up is only possible for localized pollution. Even then, it is still necessary to agree on a target value for pollution control, and therefore on the residual contamination that is left behind, which de facto contradicts the idea of total clean-up.

Similarly, on an industrial site, considerable sums were spent to treat the site, and thus produced contaminated soil now stored at the CEA (the Cadarache site). The cost of disposal of the soil is assessed at over € 2 million even though the original site is still not completely cleaned up. The pursuit of an illusory goal of total clean-up has led to considerable — and probably unjustified — expense without the goal being reached.

In its communications with the media, ANDRA must refrain from using a term as misleading and meaningless as the ‘total clean-up’.

Building development on nuclear sites in Scotland is controlled by The Town and Country Planning Act (Scotland) 1997 Chapter 8 (UK Govern­ment, 1997) and The Planning etc. (Scotland) Act 2006 (UK Government, 2006). Local councils produce planning frameworks for their strategy for building and economic developments in their geographical areas. These may contain policy statements expressing a council’s view on nuclear facili­ties or operations in their areas which may have an influence on the course of planning applications.

There is also the Scottish Councils Committee on Radioactive Substances (SCCORS), which provides a forum for discussion among those councils with nuclear interests and which can respond to nuclear issues and consulta­tions on a joint basis.