Treatment of the gaseous waste from nuclear fuel cycle facilities removes aerial radioactive particles and gaseous radioactive nuclides before dis­charge of the gaseous effluent into the environment. In reprocessing plants, the gaseous waste is filtered through scrubbers, Ag-zeolite/Ag-silica-gel filters for iodine and HEPA filters, and then discharged through a stack after radioactivity measurement to ensure it is below regulatory limits. In MOX fuel fabrication plants, only aerial radioactive particles are generated. The off-gas is passed through HEPA filters, and discharged through a stack after measuring radioactivity.

Treatment of the liquid waste from reprocessing plants removes radioac­tivity in controlled liquid discharges and eliminates process effluents. The liquid waste treatment system is composed typically of the high active liquid subsystem, the intermediate active liquid subsystem, the low active liquid subsystem, the solidification subsystem and the solvent waste subsystem. The high active liquid subsystem collects and processes typically raffinate from the separation/extraction process. This waste is concentrated by evap­oration, vitrified and stored in a dedicated interim facility.

The intermediate active liquid subsystem collects and processes effluents from the acid recovery process, the solvent washing process, the off-gas scrubber, etc. This waste is concentrated by evaporation, and then the distil­late is fed to the low active liquid subsystem.

The low active liquid subsystem collects and processes floor drain liquids, the detergent waste, etc. These wastes are distilled, then filtered and dis­charged into the ocean after activity measurement. The concentrated waste is fed to the solidification subsystem.

The solidification subsystem collects and processes the concentrated wastes from the intermediate active liquid subsystem and the low active liquid subsystem. These wastes are adjusted to appropriate pH and concen­trated by flocculation/ultrafiltration, and then solidified with cement in the Tokai reprocessing plant of the JAEA Tokai Research and Development Center. In the spent fuel reprocessing plant in Rokkasho village (Rokkasho reprocessing plant), these wastes are dried with a film evaporator and pel­letized with a granulator. The processed solid wastes are stored in the facilities.

The solvent waste subsystem collects and processes waste solvent from the solvent washing process. This waste is solidified with epoxy resin at Tokai and hydrothermally solidified after pyrolysis at Rokkasho.

Treatment of the solid waste is implemented with the aim of volume reduction for storage, because a disposal facility is not yet available in Japan for TRU waste. The combustible wastes are incinerated, and the incinerated ash is placed in 200 L drums for storage. The non-combustible wastes are placed directly in appropriate containers, and stored at the facilities. In Tokai MOX fuel fabrication plant, plastics and polyvinyl chloride (PVC) are also incinerated in a dedicated incinerator.

With stable conditions in the reactors of the Fukushima Daiichi NPP achieved, TEPCO will continue to monitor the radiation levels in the plant and carry out mid — and long-term work to achieve the following targets [33]:

1. In 2012, processing facilities for multi-radioactive nuclides, which could not be removed by the current cesium adsorption units, were installed. With the sealing of the water leakage, the processing of the accumulated water will be accomplished within 10 years.

2. To mitigate seawater contamination, seawater purification continued to be operated until the end of 2012. Furthermore, a water shielding wall will be installed by 2014 to prevent local groundwater discharge into the ocean.

3. Removal of fuel from SF pools will commence within 2 years, in the sequence of units 4, 3, 1, and 2. Complete fuel removal for all units will take about 10 years. Fuel reprocessing and storing methods will also be studied during this period.

4. After fuel removal, the leftover fuel debris will also be removed in accordance with site conditions, safety requirements, and the develop­ment of remote control technologies. This removal will be initiated within 10 years and is expected to be completed after 20-25 years.

5. The reactor facilities of units 1-4 will also be demolished within 30 and 40 years.

6. Another significant target is the processing and disposal of the radioac­tive waste. By the end of 2012, an R&D plan for the post-accident waste was set up. The R&D programme includes, but is not limited to, waste identification, effective waste treatment and disposal methods, potential equipment/device development. At this stage, the complete disposal of the RAW is expected to be accomplished after 30-40 years.

The overall mid- and long-term roadmap published by TEPCO is summa­rized in Fig. 24.9.

Options for managing the corium product of the melted cores at Fuku — shima have been considered [6] incuding stabilizing the site by creating a protective sarcophagus as is being done at Chernobyl. However, an under­standing of the interaction between water and the corium with which it would undoubtedly come into contact must be developed if this option is eventually chosen.

In December 1991, the National Assembly passed a law that gave ANDRA a new status making it independent of the CEA (see ANDRA, 1991). This law regulated in detail the feasibility study related to disposal of waste in deep geological rocks. The Agency had 15 years to complete this study. Christian Bataille (Member of Parliament for the Nord Department) was responsible of a mediation mission to seek local volunteers for the hosting on their territory of an underground laboratory.

15.3.2 1992-1999

1992-1994: ANDRA pursues its mission

In January 1992, the disposal facility CSFMA received its first waste package for disposal in concrete vaults. Also in 1992, ANDRA began to develop a specific management solution for waste coming from outside the nuclear power industry, particularly that from hospitals and used for medical training. This complex development work took nearly 10 years. Finally, in the disposal facility of the Centre de la Manche, the last package arrived on 30 June 1994, after 35 years of operations. The implementation of the waterproof cover continued, in view of the transition to the monitoring phase in 2003.

Where wastes cannot be prevented from arising, the UK strategy is aimed at minimising the volume and activity of LLW consigned for disposal through waste segregation, decontamination or decay storage. A variety of strategies are encompassed in recycling; including waste volume reduction and compaction and thermal treatment. Reuse and recycling of rubble and
metal wastes provide a further means to reduce LLW wastes. Metallic drum wastes from the LLWR are currently being shipped to the Studsvik facility at Lillyhall, Cumbria for processing to remove the radioactivity to minimise the quantities of metals disposed in the LLWR. Suitable LLW is also super­compacted under high pressure before disposal at the LLWR to minimise the volume prior to disposal.

In parallel with running down and eventual cessation in 1998 of emplace­ment of ILW into the wet silo, an above ground ILW store was brought into operation that allows retrievable storage of ILW in 200 litre drums in shielded vertical channels. Emplacement is carried out by conventional transport flasking operations.

Plutonium-contaminated material (PCM) storage

Waste is generated that has the gamma and beta radioactivity levels in the LLW range but is alpha contaminated. It is contact handleable with precau­tions, and referred to as PCM. There is an operational above ground vault store which accommodates the PCM in 200 litre mild steel drums awaiting further treatment and a final end-point being identified.

The NWPA of 1982 established the federal responsibility for the disposal of SNF and HLW. The NWPA assigned responsibilities for the disposal of SNF and HLW to three federal agencies:

1. DOE for developing permanent disposal capability for SNF and HLW

2. EPA for developing generally applicable environmental protection standards

3. NRC for developing regulations to implement EPA standards; deciding whether to license construction, operation, decommissioning, and closure of the repositories; and certifying packages used to transport SNF and HLW to the licensed repositories.

The NWPA, as amended in 1987 (Nuclear Waste Policy Amendments Act), directed the DOE to characterize a site at Yucca Mountain, Nevada, for its potential use as a deep geological repository. The geology at Yucca Moun­tain is a welded volcanic tuff and the climate is arid desert. (Other sites in salt and basalt had previously been under consideration.) However, in 2009, the Obama Administration decided that Yucca Mountain was no longer an option to be considered (see Section 18.6).

Radioisotope production and use generate a variety of radionuclides for commercial use, such as cobalt-60 for sterilization and cancer therapy units, and molybdenum-99 or other isotopes for use as tracers for medical research, diagnoses and therapy. Wastes that are generated during production are managed by the respective producers.

A number of waste management facilities process and manage the wastes that result from the use of radioisotopes for research and medicine. In general, these facilities collect and package waste for shipment to approved storage sites such as AECL-CRL. In some cases, the waste is incinerated, or retained in the facility to allow for decay to insignificant radioactivity levels and then released as clean materials.

The following criticality limitations are applicable to the WAC [12]:

• 100L to 160L drum: total 235U mass <200 g per drum

• 210 L drums containing compressed drums: total B5U mass <500 g per drum

• 210 L drums containing any other waste: total 235U mass <250g per drum.

More specific requirements are stated in Section 20.4.9.

20.1.5 Waste form requirements

1. The waste form shall be passively safe without the possibility of internal corrosion of waste container caused by the waste form or the possibility of volume increase of the waste form due to formation of corrosion products.

2. Pre-treatment, treatment and immobilization actions should be aimed at providing passively safe waste forms.

3. The waste form does not contain or have the potential to generate haz­ardous or corrosive materials unless it is demonstrated that the encap­sulating or immobilizing matrix of the waste form makes them passively safe.

4. If waste drums contain uranium metal, the following limitations are applicable:

• items shall be dry (no water, oil or grease)

• volume per item not less than 5 cm3.

• surfaces of all items to be smooth

• minimum thickness 10 mm.

The Chinese government and research communities have also paid atten­tion to the issues of radioactive waste disposal and repository siting and design. Waste generated from NPP is, for the most part, currently stored at the NPP sites where the wastes are generated as well as at research institu­tions that have reactors. The accumulated low and intermediate level radio­active waste (LILW) will eventually be sent to near-surface disposal facilities. The high level wastes (HLW) will be sent to a geological repository when it is available; this is expected to be sometime around 2050 [5-7].

Most of China’s regulations and standards are developed based on inter­national safety standards in combination with the Chinese situation. China’s current spent fuel (SF) management policy is to reprocess. However, the SF generated so far is still in interim storage, either at or away from the reactors. China’ s radioactive waste policy serves as a baseline for China’ s radioactive waste regulations, which are in place to guarantee that there will be no radioactive waste burden left for future generations.

Adapted from the IAEA regulations [8], waste producers in China must:

1. Minimize waste in fuel production and fuel cycles, materials classifica­tion and purification.

2. Guarantee a high volume reduction.

3. Use high quality waste packaging materials along with safety regula­tions that cover transportation and in-situ storage during periods when the waste may be exposed.

4. Centralize and control disposal and control release from a waste package which includes enhanced monitoring.

5. Design, construct and operate all facilities and practices for radioactive waste within these practices.

The liquid RAW generated at NPP must be immobilized and solidified. The regulations mandate that the implementers of waste disposal must be rela­tively independent from the waste producers. The waste disposal service is not chartered by or sponsored by the central government. Five regional sites in Guangdong Province, Zhejiang Province, Gansu and Beijing have been built, mainly for disposal of LILW. For HLW, including SF, current practice is to temporarily store the wastes, while the liquid RAW is being solidified.

In terms of the legislative framework, the China Atomic Energy Authority/ Agency (CAEA) is responsible for development of policies concerning the peaceful uses of nuclear energy:

• development of industry standards;

• control of nuclear materials;

• acting as a leading body for nuclear accident response, in particular for organizing the State Committee of Nuclear Accident Coordination;

• reviewing and approving the nuclear energy development project;

• reviewing and approving R&D projects.

The People’s Congress developed the Regulatory Framework Act to address some issues with the signed Presidential Regulations. The State Council is responsible for the promulgation of regulations, which are issued with the signature of the Prime Minister.

The uranium refining and conversion plant (URCP) at Ningyo-toge was constructed in 1981 to demonstrate refining and conversion of yellow cake (or uranium trioxide) to uranium hexafluoride via uranium tetrafluoride. There are two different types of refining processes in the URCP. One is the wet process for converting natural uranium and the other is the dry process for reprocessed uranium.

Dismantling of the dry process facilities began in March 2008. The basic strategy concerning plant dismantling was to optimize the total labour costs and minimize the radioactive wastes generated. The basic schedule for dismantling is as follows.

• Phase 1: removal of large equipment or processes involving uranium hexafluoride,

• Phase 2: removal of the greater part of the utilities connecting the main process of URCP,

• Phase 3: removal of equipment of main process,

• Phase 4: removal of ventilation systems.

The majority of equipment will be dismantled, except for building decon­tamination, by 2013. A large amount of fluidization media had been stored in tanks held underground in the URCP. The fluidization media is com­posed of small aluminum pellets which absorbed uranium oxides or unre­acted uranium tetrafluoride used for the fluorination reaction. They therefore contain high levels of uranium and thorium as progenies of U-232. Among its progenies, Tl-208 is a high gamma emitter, so some external exposure will arise in handling the fluidization media.