Experience also shows that many operations rely on trades from different core businesses than that of the ‘remediator’. In particular, sites often rely on experts for asbestos removal, demolition of buildings, work on hydrol­ogy, management of conventional toxic waste, management of radon in buildings, the maintenance of building structure, etc. ANDRA’s agents have a duty to draw on the external expertise needed to better adress the risks that are poorly controlled or not controlled at all inside ANDRA. Again, any initial savings on these aspects can cost dearly later.

Low level liquid effluent (LLLE) and gaseous low level waste are dis­charged from nuclear installations in Scotland into the environment within volumetric and radioactivity limits which are specified in authorisations that are granted by SEPA. The site operators are required to manage discharges to be as low as reasonably practicable (ALARP). They are required to produce implementation control documents that demonstrate best practi­cable means (BPM) and best available technology (BAT). SEPA regulates the site operators against both the authorisations and the implementation control documents. SEPA’s policy is to encourage nuclear site operators to drive down liquid and gaseous discharges to the absolute minimum. In some cases this involves transferring the radioactivity from liquid and gaseous effluents to a solid medium to create a disposable LLW.

18.1.2 Legislative system

The policy on regulatory control of RAW management in the United States has evolved through a series of laws establishing federal agencies respon­sible for the safety of radioactive materials. Federal legislation is enacted by Congress and signed into law by the President. US laws apply to all 50 states and its territories. Table 18.1 identifies key US laws governing radio­active waste management; pertinent legislation on the safety of SNF and RAW dates from the 1950s.

TRU waste is a type of RAW that contains elements with atomic numbers greater than uranium (DOE, 2009). This waste consists primarily of clothing, tools, rags, residues, soil, debris, and other materials contaminated with plutonium; it may also be mixed with hazardous components. There are two categories of TRU waste: CH TRU waste can be handled by workers under very controlled conditions with no shielding for radioactivity other than the container itself, while RH TRU waste must be handled and transported in lead-shielded containers and casks because it emits more penetrating radiation. CH TRU represents 96% of the total volume of TRU waste to be disposed of at WIPP, while RH TRU makes up the remaining 4%.

Before WIPP opened, 28 DOE sites were storing TRU waste in a variety of configurations, primarily below-grade to contain the radioactive ele­ments while also allowing for its eventual retrieval for disposal. After nearly 20 years of testing, scientific research, engineering and design, and regula­tory permitting, WIPP began receiving CH TRU waste in 1999. In 2006, WIPP received final authorization to begin accepting RH TRU and the first shipment, from INL, arrived in January 2007.

Located 2,150 feet below ground in a 250 million-year-old salt formation, WIPP is the world ’s only operating deep geological repository. An esti­mated 150,000 m3 of CH TRU and 7,000 m3 of RH TRU resulting from US Cold War defense activities will ultimately be disposed of there.

Between 2002 and 2008, the DOE de-inventoried all legacy TRU waste at 14 sites, thereby eliminating associated management costs at these sites as well as environment, safety, and health risks. TRU waste was also removed from facilities at the NNSS, Lawrence Livermore National Laboratory, and Argonne National Laboratory (ANL) so they can support other missions.

As of February 2013, WIPP had received 11,112 shipments of TRU waste since it opened in 1999. These years of experience and a streamlined regula­tory framework have resulted in more efficient and routine operations with each passing year. The DOE has a clear strategy for building on this past success to meet its TRU risk reduction goals:

• characterize a small quantity of waste in Idaho for shipment to WIPP

• expand use of Central Characterization Project (CCP)

• facilitate shipping sites in certifying waste for acceptance at WIPP

• expand number of sites certified for RH shipping

• deploy shielded containers for shipping RH TRU.

This strategy includes expanding the number of sites certified for RH TRU shipping. To support and enhance this strategy, the DOE continues to develop shielded containers for RH TRU lead-lined drums that allow RH TRU waste to be handled, shipped, and potentially disposed of in a manner similar to CH TRU waste. Currently, RH TRU waste is emplaced in bore­holes along the walls of the WIPP repository and CH TRU waste is placed on the floors.

Significant coordination is required for optimal and efficient emplace­ment of RH TRU and CH TRU waste. The use of shielded containers for placement of selected RH TRU waste on the floors of the repository could increase the efficiency of disposal operations at WIPP. The DOE is actively pursuing the necessary regulatory approvals needed to move forward with shipping and disposing of RH TRU waste in shielded contain­ers at WIPP.

Another TRU waste risk-reduction strategy is the characterization of small-quantity TRU waste sites in Idaho for shipment to WIPP. A Record of Decision (ROD) approved in February 2008 allows the DOE to send waste from small-quantity sites to INL for treatment, characterization, and shipment to WIPP, assuming the waste meets INL waste acceptance criteria. This reduces costs by eliminating the need to construct TRU waste treat­ment facilities at sites with small quantities of TRU waste. It also results in faster removal of TRU from these sites and a greater economy of scale for the TRU waste facility at INL.

The DOE is also expanding the use of the CCP at large sites. The project employs a modular waste characterization system consisting of full disposal characterization equipment for both CH TRU and RH TRU waste and a mobile loading system used to place drums of TRU waste into shipping containers for transport to WIPP. CCP has proven successful in character­izing waste more cost effectively through use of a standard suite of proce­dures, quality assurance documents, and equipment.

Another strategy includes the use of TRU waste expert teams to assist generator sites in certification and characterization planning for waste streams that are more difficult to manage, such as those requiring additional documentation, treatment, or packaging. These teams help to ensure all TRU waste is characterized, shipped, and disposed of at WIPP.

The DOE has designed a new cask, TRUPACT-III, for TRU waste pack­aged in large boxes that cannot be shipped in currently available transporta­tion casks due to their size. The strategy to ship and dispose of large-size containers at WIPP also requires the development, deployment, and regula­tory approval of equipment needed to determine the contents of large containers. With this knowledge, the potentially dangerous and costly task of reducing the size of large containers before shipment and disposal at WIPP can be avoided.

ILW is waste which has limited heat generation capacity that need not be considered for its disposal or in its disposal option (typically below 2 kW/m3) with intermediate short-lived and/or intermediate long-lived radionuclide concentrations. ILW consists mainly of irradiated uranium (uranium, actinides, other activation products and fission products) in smaller quantities, or cooled irradiated uranium or in the form of irradiated uranium contaminated waste as generated in the isotope production facili­ties and the operation of the SAFARI research reactor. Unirradiated uranium (from the NFC) could also fall into this waste class, especially when it occurs in higher concentrations. Waste management is aimed at prevent­ing unirradiated uranium falling into this waste class. Long-lived sealed sources, for example Ra-226 or SHARS (spent high activity sealed radioac­tive sources) could also fall in this waste class. SHARS of shorter lived radionuclides may have such high activity levels that the intrusion dose after the institutional control period is in excess of 10 mSv/a as specified for near surface disposal.

The long-lived radionuclide half life (Ti/2 > 30.2 years) concentrations could on average typically be 4,000 Bq/g and 40,000 Bq/g for a and в у emit­ters, respectively. Criteria for long-lived radionuclide concentrations need to be justified for a specific repository. Criteria are justifiable in the case of a specific repository if inherent intrusion dose after the institutional control period is between 10 mSv/a and 100 mSv/a.

For irradiated uranium waste, containers are shielded to ensure surface dose rate levels <2 mSv/h. Unirradiated uranium waste could be pre-treated in unshielded containers. ILW that is removed from authorized containment systems shall be processed to ensure a solid waste form in a waste package that is suitable for handling, transport and storage for a period of 50 years. Additional requirements may be prescribed for a specific ILW repository. Corporate pre-disposal management standards need to be specified to ensure good practice and waste packages that are compliant and verifiable in terms of the applied IAEA standards [5]. These generic standards ought to be used as reference standards for the evaluation of ILW disposal con­cepts and for the long-term safety of planned ILW repositories. Disposal of ILW needs a high degree of containment and isolation from the biosphere over a long period of time that is obtainable by intermediate disposal at depths of tens to hundreds of metres.

Radioactive wastes arise from the generation of electricity in nuclear power stations and from the use of radioactive materials in industry, medicine, research, and military. There is a wide spectrum of wastes, from those that contain high concentrations of radioactive materials, to general industry and laboratory wastes which are only lightly contaminated with activity.

The Atomic Energy Act (AEA, Article 2.18) of the Republic of Korea defines ‘radioactive waste’ as radioactive materials or materials contami­nated with radioactive materials which are subject to disposal, including spent fuel. The Enforcement Decree of the AEA defines high-level radioac­tive waste (HLW) as radioactive waste with radioactivity concentration and heat generation over the limiting volume specified by the Ministry of Edu­cation, Science, and Technology (MEST). In the strict sense, wastes other than HLW belong to the LILW category in accordance with the AEA. The limiting values on radioactivity and heat generation rate are specified in the MEST Notice No. 2008-31 (Notice of the Standards on Radiation Protec­tion, etc.) [MEST, 2008] as follows:

• radioactivity: >4,000 Bq/g for alpha-emitting radionuclides with a half­life of longer than 20 years

• heat generation rate: >2 kW/m3.

The AEA also defines the clearance level adopted from the ‘exempt waste’ concept of the IAEA radioactive waste classification. The clearance levels in Korea are such that annual individual radiation dose shall be less than 10 pSv/y and the total collective dose below one person-Sv/y concurrently. These are the same as the levels specified in the IAEA Safety Series No. 115 (1996) [IAEA, 1996].

All radioactive wastes are still to be stored in on-site temporary storage until a permanent disposal facility has been constructed. The amount of radioactive waste being stored by April 2012 is 89,865 drums from nuclear power plants (KHNP, 2012). (Hereafter, ‘drum’ means ‘200-liter drum equivalent’ unless otherwise stated.) The total capacity of temporary storage in NPP sites is 109,900 drums and the accumulated radioactive waste stored at each NPP site is around 77.7% of their storage capacity, as shown in Table 21.1 . Although the volume of waste arising from radioisotope use is still relatively small compared to power reactor waste volume, the annual gen­eration rate is expected to rise rapidly as industrial use of radioisotopes increases. The waste type and volume of LILW is shown in Fig. 21.2.

Japan has carried out nuclear power generation research since the middle of the 1950s. A test power reactor, the Japan Power Demonstration Reactor (JPDR), started operation in 1963 and Tokai-1 Nuclear Power Plant (NPP), the first commercial reactor, went into operation in 1966 with a generation capacity of 166 MWe. Currently, about 50 commercial nuclear reactors, predominantly boiling water reactors (BWRs), and pressurised water reactors (PWRs), are in operation, with a total generation capacity of 48,847 MWe. Prior to the Fukushima disaster, about 30% of Japan ’s electricity came from nuclear power (Plate VIII between pages 448 and 449). Japan will continue to develop nuclear power as a mainstay of non-fossil energy, while placing the highest priority on safety1.

The Framework for Nuclear Energy Policy (FNEP), which was estab­lished by the Japan Atomic Energy Commission (JAEC) as the basics for political measures regarding the use of nuclear power generation and radia­tion to be promoted by governmental agencies for the next 10 years, was approved by the Cabinet in October 20052.

Prior to the events at Fukushima, nuclear energy was expected to con­tinue to contribute to the pursuit of an optimum energy supply mix for Japan. The FNEP specified that nuclear power’s share of Japan’s total power generation should be maintained at 30-40% or more beyond 2030 and that the nuclear fuel cycle should be promoted3. Nuclear power genera­tion is the key base-load power source. After Fukushima, in July 2011, the Energy & Environment Council (Enecan or EEC) was set up by the Cabinet Office to recommend on Japan’s energy future to 2050. It is chaired by the Minister for National Policy and will focus on future dependence on nuclear power. In September 2011, Japan ’ s prime minister said he expected the country to reduce its dependency on nuclear power in the medium and long term, and that the government would address the question of those new plants now under construction. He said that the national Basic Energy Policy would be revised from scratch, and that a new strategy and plan to 2030 would be created. He also stated that Japan’s ministerial-level Energy and Environment Council would ‘thoroughly review nuclear policy and seek a new form’. The review may recommend that nuclear power’s contri­bution to electricity be targeted at 0%, 15%, or 20-25% for the medium term — a 36% option was dropped.

The Fukushima NPP accident resulted in the spread of radionuclides into the atmosphere. The radionuclides were volatilized by the high temperature in the reactor core and during the explosions and fires. In addition, seawater containing non-volatile activation products and fuel rod materials may have been released into the subsurface and ocean environment [22]. The fate and potential transport mechanisms of these radioactive materials are shown in Fig. 24.2 ; the illustrated atmospheric, terrestrial, and aquatic systems were all affected by the accident. Since some long-lived radionuclides were among the released radioactive materials, the radioactive contaminants may have a profound impact on the environment, food, and human health through their migration between and within these systems.

When a camouflet explosion occurs under high temperature (over a million degrees Kelvin) and high pressure (order of several million atmospheres), evaporation and melting of rock occurs in the region where the charge was laid, resulting in a boiler chamber having a shape similar to a three­dimensional ellipsoid. The effective radius of this cavity is 10-40 m. The cavity wall thickness is several tens of centimeters, composed of sintered layers of rock. The mass of the melt reaches 400 m at 1 kiloton of explosive power. Behind the wall cavity, as a result of the shock wave, is crushed rock. At large distances behind the wall cavity, is a region of increased fracturing. A truncated cylinder shape is formed with the upper limit in the cleavage zone impacting the surface of the Earth above the boiler cavity zone where increased fracturing occurs (Israel, 1974).

Over time, gravity causes the melt to flow down from the top and side walls of the cavity to its lower part, forming a lens of melt. After a further decrease in temperature, the melt passes into a solid phase and is partially or completely embedded with fragments of rock up to a height of a few meters from the bottom of the cavity. In this case, the bottom layer of the fractured rock pile covers the lens of melt. The array of the rock above the boiler cavity has been destroyed and eventually starts to sink down to form a pillar collapse. This process partially reverses the expansion of soil and rock mechanical faults caused by the shock wave, but also lowers the gas pressure in the cavity that was formed. Since the diameter of the column collapses the diameter of the boiler cavity, the cave only partially fills the cavity, forming one or more hollow zones located closer to the surface. The pillar collapse has very high moisture and gas permeability. The associated, filtration coefficient is hundreds of meters per day, and the coefficient of loosening of pillar collapses, defined by the ratio of porosity before and after the explosion, reaches 0.73-0.85. At the same time, the lateral border pillar collapses and is clearly separated from the solid undisturbed rock. At the point of contact, the lateral border pillar collapses along with the adja­cent undisturbed rock to form a peeled zone with permeability greater than the permeability of the collapsed column. At the ground surface above the explosion zone epicenter cleavage phenomena were observed. These took the form of swelling or rock subsidence depending on the exact nature of the explosion. Often crushed rocks are observed on the rock — similar arrays in the cleavage zone.

Because of the complexity of nuclear processes, a range of radionuclides are released in the explosion, which are deposited mainly in the cavity of the explosion. High-melting products are concentrated mainly in the lens of the melt and are mostly fissile nuclides of uranium and plutonium, fission fragments and neutron-activated elements of the charger and breeder. In the column collapse and fracture zone, volatile compounds such as pluto­nium and polonium are concentrated, as well as the radionuclides stron­tium, cesium, lanthanum, etc. (Israel, 1974).

15.1.1 Waste sources and categories

The various types of RAW are classified according to the half-lives and radioactivity levels of the main radionuclides they contain, to their physical and chemical characteristics, as well as to their origins. Half-lives are divided into very-short (less than 100 days), short (between 100 days and 31 years) and long (over 31 years).

In France, there are six major waste categories depending on their radio­active content (activity level and half-life), as follows:

• High-level waste (HLW) consists mainly of vitrified-waste packages in the form of stainless-steel containers, which contain the vast majority of radionuclides, whether in the form of fission products or of minor acti­nides. Radionuclides contained in spent fuel are separated from pluto­nium and uranium during fuel reprocessing at the La Hague plant. The activity level of vitrified waste is on the order of several billions of Bec — querels per gram.

• Long-lived intermediate-level waste (LL-ILW) originates mostly from the reprocessing of spent fuel and consists of structural residues from nuclear fuel (i. e., hulls (sheath sections) and ends, which were condi­tioned initially into cemented waste packages, but are now compacted into stainless-steel containers). It also includes technological waste (e. g., used tools, equipment, etc.) and residues resulting from the processing of effluents, such as bituminized sludge. The activity of these residues ranges between 1 million and 1 billion Becquerels per gram. There is either no or a negligible heat release.

• Long-lived low-level waste (LL-LLW) consists mainly of graphite and radium-bearing waste. The activity of graphite waste lies between 10,000 and 100,000 Becquerels per gram. Its long-term activity arises from long-lived beta-emitting radionuclides. Radium-bearing waste contains long-lived alpha-emitting radionuclides and their activity lies between a few tens to a few thousands of Becquerels per gram.

• Short-lived low — and intermediate-level waste (SL-LILW) results mainly from the operation and dismantling of nuclear power plants (NPP), fuel cycle facilities and research establishments, as well as, for a small amount, from activities relating to biological and academic studies. Most residues in this category were disposed of in a surface facility at the Centre de la Manche disposal facility (CSM) up until 1994 and at Centre de l’Aube disposal facility for LILW (CSFMA) since 1992.

• Very-low-level waste (VLLW) is mostly from the operation, mainte­nance and dismantling of NPPs, fuel cycle facilities and research estab­lishments. Its activity level is generally lower than 100 Becquerels per gram. All residues of this category are disposed of at the Centre de l’Aube disposal facility for VLLW (CSTFA).

• Very-short-lived waste includes residues that result notably from medical uses.

For practical purposes, the acronyms listed in Table 15.1 are often used.