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All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

U.S. Nuclear Regulatory Commission Historical Perspectives of Very Low-Level Radioactive Waste - 18367

The United States Nuclear Regulatory Commission (NRC), in Title 10 of the Code of Federal Regulations Part 61 (10 CFR Part 61), 'Licensing Requirements for Land Disposal of Radioactive Waste', provides licensing procedures, performance objectives, and technical requirements for the issuance of licenses for the land disposal of low-level radioactive waste. Low-level radioactive waste is divided into four categories based on its potential risk and need for isolation. Class A is the lowest category of low-level radioactive waste and poses the least risk. A large percentage of Class A low-level waste contains very low radionuclide concentrations and does not pose a significant health and safety risk. In the current regulatory framework, this waste, referred to as low-activity or very low-level waste, is managed in the same manner as much more hazardous waste. In 1986 and 1990, as a result of the Low-Level Radioactive Waste Policy Amendments Act of 1985, the NRC issued the Below Regulatory Concern (BRC) policy statement. This policy statement established an implementation plan regarding the expeditious handling of rulemaking petitions 'to exempt specific radioactive waste streams from regulation due to the presence of radionuclides in sufficiently low concentrations or quantities as to be below regulatory concern.' The BRC policy statement provided a consistent risk framework when considering regulatory exemption decisions, such as: (1) the release for unrestricted public use of lands and structures containing residual radioactivity; (2) the distribution of consumer products containing small amounts of radioactive material; (3) the disposal of very low-level radioactive waste at other than licensed disposal sites; and (4) the recycling of slightly contaminated equipment and materials. Due to concerns with the BRC policy that were raised by Congress, the States, the public, and others, Congress enacted the Energy Policy Act of 1992, which revoked the NRC's 1986 and 1990 BRC policy statements and led to the NRC's formal withdrawal of the BRC policy in 1993. Stakeholders raised concerns on NRC's potential deregulation of radioactive material. Additionally, in March 2005, the NRC staff proposed a rule to amend 10 CFR Part 20, 'Standards for Protection Against Radiation,' to include radiological criteria for controlling the disposition of solid materials with very small amounts of residual radioactivity. The NRC staff also proposed a limited disposition approach for the disposition of solid material, limiting the release of solid material meeting a 0.01 milli-Sievert per year (mSv/yr) [1 milli-rem (mrem/yr)] dose criterion, from licensed control. In June 2005, the Commission disapproved publication of the proposed rule and deferred the rulemaking until a later time, stating that the NRC's existing approach of reviewing specific cases on an individual basis was fully protective of public health and safety. This rulemaking effort was discontinued by the Commission in 2016. Recently, several nuclear power plant licensees have announced early decommissioning of their facilities. Some stakeholders have expressed concerns about the capacity and disposal costs associated with using the four existing low-level waste disposal sites for very low levels of radioactive waste (i.e., waste at the low end of the Class A category). A more risk-informed, performance based approach to waste disposal would allow more flexibility in managing this waste commensurate with its risk and hazard. A new approach would also allow the NRC to align with international standards for this type of waste. The NRC is presently conducting a scoping study to identify the actions the agency should take to strengthen its regulatory framework for very low-level waste disposal. The Very Low-Level Waste (VLLW) scoping study will consider divergent stakeholder comments; lessons learned from the BRC policy statements and the proposed rule on radiological criteria for controlling the disposition of solid materials; and best practices of other countries with respect to VLLW disposal. The NRC will also engage other government agencies to discuss regulatory options for VLLW. This paper offers a historical overview of past NRC initiatives to manage the lower end of Class A waste in a manner that is risk informed and performance based. It examines previous endeavors and discusses the regulatory challenges that arose. It also addresses lessons learned and introduces NRC's current effort regarding very low-level radioactive waste disposal. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Development of Processing Technology for Radioactively Contaminated Water at Chernobyl Nuclear Power Plant - 19656

During the operation of the Chernobyl Nuclear Power Plant, distillation by evaporation was the main method for processing radioactively contaminated water. When the plant was decommissioned, the evaporation facility was mothballed and floor drain treatment was suspended in 2016. At present, the existing tanks with the capacity of 26,000 m{sup 3} are more than 60% full with radioactively contaminated floor drains, which requires alternative processing methods. The current process flow for radioactive waste management at State Specialized Enterprise 'Chernobyl NPP' includes processing of accumulated liquid radioactive wastes at a liquid radioactive wastes processing plant. Under the processing technology, liquid radioactive waste is immobilized at the plant by cementation and the resulting solid radioactive waste is then buried in a near-surface storage. Key factors for the selection of alternative radioactively contaminated water processing methods are the possibility to clear the processed water (no control monitoring), which requires the same degree of processing as for drinking water, and minimization of radioactive waste generation due to the lack of free space for solid waste disposal in the near-surface storage. Floor drains that require processing contain radionuclides such as {sup 137}Cs, {sup 90}Sr, {sup 60}Co and {sup 40}K. The current level of the total beta and gamma activity is about 4*105 Bq/kg. The following criteria are set for the Chernobyl NPP site for water to be disposed to the sewerage system: - Max. 37 Bq/kg for the total beta and gamma containing radionuclide activity; - Max. 0.7 Bq/kg for the total alpha containing radionuclide activity. METOIL produces inorganic sorbents for removing radionuclides from liquids and develops sorbent-based technology for a variety of applications related to liquid radioactive waste processing. In 2017-2018, experts from the Chernobyl NPP and METOIL ran several joint laboratory tests to evaluate the efficiency of inorganic sorbents made by METOIL for processing floor drains at the Chernobyl NPP. The test procedure included treatment of radioactively contaminated water in a two-stage sorption process: static sorption (sorbents are mixed in a liquid) and dynamic sorption (the liquid is filtered through a sorbent column). NIKET and MODIKS sorbents were provided for the tests. The results of the test measurements showed that the total alpha containing radionuclide activity is less than 0.026 Bq/kg and the total beta and gamma containing radionuclide activity is 9.2 Bq/kg. The physical and chemical parameters after processing also met the water disposal criteria. High sorption capacity of the sorbents used for the tests allows processing hundreds of water volumes with just one sorbent volume. At present, preparations are underway for full-scale tests at a pilot plant with a capacity of minimum 10 m{sup 3}/day. At a later stage, spent sorbents may be immobilized by inclusion into the cement matrix, which will substantially reduce the amount of radioactive waste to be buried. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

A proposed solution to the challenges of disposal of greater than class C low-level radioactive waste - 15172

In 1982, the US Nuclear Regulatory Commission (NRC) adopted rules for the disposal of low-level radioactive waste. These rules established new standards for the siting, construction, operation and closure of low-level radioactive waste disposal facilities. The new rules also set out a classification system for low-level radioactive waste based on half-life and concentration of the radionuclides in the waste stream. The defined classes - Class A, Class B and Class C - were based on increasing toxicity with Class A being the least hazardous and Class C being relatively more hazardous. Radioactive waste that could not fit the classification scheme due to its long half-life or its high concentration of radioactive material was deemed to be greater than Class C low-level radioactive waste, with the ascribed acronym 'GTCC' low-level radioactive waste. Such waste was deemed not suitable for shallow land disposal based on the design standards for low-level radioactive waste landfills in place at that time. This resulted in a radioactive waste stream that had no disposal option. To remedy this problem, the US Congress in 1985 stipulated that the US Department of Energy would be responsible for the disposal of GTCC waste. Subsequently, the NRC amended its regulations to require GTCC low-level waste to be disposed in a geologic repository unless the Commission approved proposals for disposal in a low-level radioactive waste disposal facility. The Commission did not concurrently establish any specific technical requirements for GTCC disposal in a low-level radioactive waste disposal facility, but did infer that a site-specific performance analysis could be conducted in support of any proposal for land disposal of such waste. In light of this, Waste Control Specialists LLC (WCS) has conducted such a site-specific performance analysis that has indicated the disposal facility at Andrews Texas will perform satisfactorily as a disposal facility for certain types and quantities of GTCC waste. Concurrently with this analysis, WCS has submitted to the Texas Commission on Environmental Quality a petition for rulemaking that will permit disposal of GTCC waste in their disposal facility. This paper summarizes the technical and legal analyses that were conducted in support of the proposed rulemaking. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

A Study on the Comparison of International WTS for Integrated Management of Radioactive Waste - 19034

Domestic radioactive waste is generated by nuclear power plants, the Korea Atomic Energy Research Institute and KEPCO Nuclear Fuel Company. These nuclear energy agencies have their own waste tracking system. To track waste more efficiently, it is necessary to build an integrated tracking system from the viewpoint of the final disposer. As for the korea Atomic Energy Research Institute, the decommissioning waste due to the decommissioning of research reactors No. 1 and 2, and the low and intermediate-level radioactive waste, generated by the operation of the High Flux Advanced Neutron Application Reactor(HANARO), account for the most. The solid waste from each facility and laboratory is sorted and collected according to radiation levels and the contents. For starters, according to the contents, the waste is divided into combustible, noncombustible compressible and non-compressible waste. The combustible waste, generated by the Korea Atomic Energy Research Institute, is treated according to the low and intermediate-level radioactive waste delivery regulation of the Nuclear Safety and Security Commission and the acceptance criteria of the disposal facility. KEPCO Nuclear Fuel Company is making the nuclear fuel used in nuclear power plants. Radioactive waste is generated in the nuclear fuel manufacturing process, and it is classified into 8 types of waste according to the solid waste management procedure. Most of the radioactive waste, generated while KEPCO Nuclear Fuel Company processes the light-water reactor and heavy-water reactor nuclear fuel, is classified as low and intermediate-level radioactive waste. The radioactive liquid waste, generated in the radiation controlled area in nuclear fuel processing facilities, is divided into low-concentration liquid waste and high-concentration liquid waste. The miscellaneous solids, generated in the Hanbit NPP of Korea Hydro and Nuclear Power Co., Ltd., are classified in consideration of the physical properties, density and amount of the waste, and substances subject to restricted disposal. This paper investigated information on the structure, functions and maintenance of the systems implemented and operated by individual countries and IAEA, and the types of managed data, and analyzed the detailed configuration of the system and the characteristics of DBMS (Data Base Management System), and discovered during the analysis process the information on the waste management in each country or institution. This paper investigated the classification standards and treatment methods according to the characteristics of the radioactive substances handled by each agency. These classification and treatment methods can be applied to the database when the radioactive waste tracking system is implemented in the future. Also, this paper analyzed the radioactive waste tracking system of each country. Most overseas waste tracking systems are configured based on the ORACLE DBMS. The ORACLE DBMS is highly secure, and can manage large-scale databases. Also, Germany's ReVK and US IWTS are using the Bar-Code system that can track and manage all waste data, generated during decommissioning or transportation, in real time, and the real-time tracking system of web-based US CID can simply create and output reports quickly. If the advantages of overseas waste tracking systems are added to the domestic integrated waste tracking system, more efficient and safer management of radioactive waste will be possible.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Radioactive Cs behavioral analysis in the incinerator at garbage incineration - 15031

About 4.7 kg cesium 137 (Cs{sup 137}) and about 0.3 kg cesium 134 (Cs{sup 134}) were released to the atmosphere around Fukushima Prefecture by the accident of the Tokyo Electric Power Company Fukushima Daiichi nuclear power plant accompanying the Great Earthquake in East Japan, which occurred on March 11, 2011. In the general incineration system which a local government owns, the garbage to which radioactive cesium (Cs) adhered (less than 8000 Bq/kg) is incinerate usual time. Before incinerating the garbage to which radioactive Cs has adhered, we did the preliminary test. As a result, if a very special case is removed, it is checked by measurement that radioactive Cs is not released from an exhaust stack of general incineration system. Our research is the elucidation of the mechanism by which radioactive Cs contained in garbage is not again released to the atmosphere with combustion gas. Concretely, we focus on the agglomeration of Cs molecular and deposition of radioactive Cs particles to the ash particle that occurs at the time of refuse incineration. And we formulated the simulation model for analyzing this phenomenon. It is presumed from an analysis result that radioactive Cs is not re-releasing by the following reasons. First, radioactive cesium hydroxide (Cs(OH)) adhering to garbage changes to radioactive cesium oxide (CsO{sub 2}) by an incineration process. Furthermore, it changes to radioactive cesium chloride (CsCl) via Cs. CsCl and Cs(OH) molecules deposit to the surrounding incineration ashes (main ashes and fly ash), in form of agglomerations. About fly ash, agglomeration and deposition are occurrence from a combustion chamber to bag filter via flue and temperature reducing tower. All radioactive Cs deposits to fly ash and main ash particles in this process. Therefore, radioactive Cs is not re-released to the atmosphere with combustion gas. Also about the main ashes, the same phenomenon occurs. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

International Implementation of IAEA's Borehole Disposal Concept for Sealed Radioactive Sources - 18545

With funding from the Government of Canada, and support from the U.S. Nuclear Regulatory Commission's (NRC's) Office of International Program and many others, the International Atomic Energy Agency (IAEA) is supporting the field deployment of the Borehole Disposal Concept (BDC) for secure disposal of radioactive sources in Ghana, the Philippines and Malaysia. This is a first-of-its-kind implementation. Though small in volume, disused sealed radioactive sources can be intensively radioactive and create a significant safety and security liability for the majority of the 168 Member States in the IAEA. Millions of sealed radioactive sources have been manufactured since 1901, and it is estimated that hundreds of thousands are now unwanted. The irony is that some of the countries with the smallest inventories have the greatest difficulties managing their radioactive wastes. The BDC was originally conceptualized in an IAEA-study undertaken by the South African Nuclear Energy Corporation (NECSA) for countries with small inventories of disused sealed radioactive sources. There are multiple, passive engineered and natural barriers in the BDC design, including an inner stainless-steel capsule (which holds the wastes), an inner cement containment barrier, an outer stainless steel container and outer backfill cement, as well as the surrounding geosphere. In common subsurface geochemical environments, these barriers will isolate the wastes from the biosphere, provide effective containment and ensure long-term safety. To greatly limit the likelihood of inadvertent human intrusion (safety), and deliberate human intrusion (security), these waste packages will be disposed of in a narrow diameter borehole (26 cm) at depths greater than 30 m. This type of borehole disposal creates an exceptionally small footprint, removes the wastes from normal human surficial activities, and isolates the waste packages from near-surface processes. Over the past 20 years, the IAEA, NECSA and many others have advanced the BDC on the shoulders of the IAEA's broader work supporting safe and secure disposal of radioactive wastes and management of sealed radioactive sources. With recent funding and support from many others, the IAEA has assisted Ghana, Malaysia and the Philippines in assessing their inventories and conditioning their disused sealed radioactive sources, in drilling investigation boreholes and characterizing their proposed sites, and in designing their disposal systems. These countries plan to place the uppermost waste package at depths greater than 100 m. While activities in the Philippines remain focused on-site characterization, Ghana is in the latter stages of developing their Safety Case for operational and 'post-closure' safety and Malaysia has completed their Safety Case and submitted a license application to construct and operate a BDC facility. Though this paper identifies the support provided to Member States by the IAEA, it is the Ghana Atomic Energy Commission and the Malaysian Nuclear Agency that are responsible for the safety and security of the disposals and that have been responsible for carrying-out their disposal programs. Once the BDC is licensed by the relevant national regulatory bodies, these first-of-a-kind disposal approaches will provide a template for other countries to safely dispose of their disused sealed radioactive sources - permanently eliminating their safety and security liabilities. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Transportation of Low-Level Radioactive Waste from KAERI to the Final Repository - 18179

The Korea Atomic Energy Research Institute (KAERI) collects the radioactive wastes generated during the operation of nuclear facilities and R and D processes. Radioactive wastes are treated and repackaged according to the national radioactive waste management policy, and then transferred to the final disposal site at the Korea Radioactive Waste Agency (KORAD). After 2015, the wastes delivered to the final disposal site have consisted of spent filters and combustible wastes such as clothes and gloves generated during R and D or facility operation processes at KAERI. The wastes generated by each facility are collected at the radioactive waste treatment facility, then treated and repackaged in 200 L drums according to their generation characteristics, i.e. each drum contains waste of the same type from the same facility, and with the same date of generation. Then, a radionuclide inventory is obtained for the repackaged drum by using a direct measurement method such as the drum assay system, radiochemical analysis through random sampling or an indirect measurement method such as applying a scaling factor. When performing sampling of the radioactive waste drums, the waste samples with a high contamination are selected in a conservative approach as representative. The radioactive waste drums are inspected and checked for acceptability by the Quality Management Division of KAERI, and a preliminary inspection is carried out on-site by KORAD. At this time, the acceptability of the radioactive waste drums is assessed through visual inspection, the appropriateness of their nuclide analysis value is confirmed, and a survey or smear test of sample drums is performed. Drums that meet the acceptance criteria are transferred to KORAD after a radiation environmental impact assessment of the transportation. Since 2015, 1,084 low-level operational radioactive wastes have been transferred from KAERI to the final disposal site, and further preparation work is now being made for the transportation of additional drums. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Development of In-Situation Radioactivity Inspection System for Food Materials

The impacts on the ocean of releases of radionuclides from the Fukushima nuclear power plants remain unclear. Korean people worry about radioactive contamination of Japanese and Korean sea products. Radioactive contamination of processed foodstuffs, livestock, sea products, farm products imported from Japan and fishes caught in coastal oceans of Korea has become an important social issue. Recently, there are also needs of inspection system for monitoring of public meals such like school feedings of kindergarten, elementary/middle/high school and university. Radioactivity inspections of food materials have been executed manually with portable measuring instruments or at labs using their samples. But, it's very important the radioactivity inspection should be performed at the field of feeding facilities. To protect the health of people from radioactivity contained in Japanese marine products imported to Korea, a system to inspect radioactivity in real time has been developed. The system is to measure the radioactivity level of farm and marine products and public meals continuously and automatically at inspection sites of an agency checking radiation of imported foodstuffs or school. The performance test of NaI(Tl) detector was examined using the quantified Cs-137 source 10 Bq/kg, 30 Bq/kg, 50 Bq/kg, 300 Bq/kg and 900 Bq/kg at Korea Research Institute of Standards and Science(KRISS). Source was put in a box and radioactivity was measured in the middle of the box. First of all, Background was measured and calibration was performed using the Cs-137 300 Bq and Ba-133 3700 Bq for 60 minutes. After setting the background and calibration data, tests of the Cs-137 10, 30, 50, 300, 900 Bq/kg were executed for 10 minutes. A peak-shaped graph is shown at the location of 662 KeV (80∼100 channel). This is due to the gamma radiation energy with 662 KeV emitted by the Cs-137. Because through KRISS examination, the MDA (minimum detectable activity) is about 23 Bq/kg, it is reasonable Cs-137 10 Bq/kg cannot be measured. And in cases of Cs-137 300 Bq/kg and 900 Bq/kg, there are some peak movement on the graph. It can be adjusted by controlling gain or high voltage. The examination was identified through the performance test (Cs-137 10, 30, 50, 300, 900 Bq/kg) at KRISS. In order to increase the measurement efficiency of Cs-137 and the system performance, database will be built up based on radioactivity measurement results from 10 to 300 Bq/kg with the unit 10. Thus, Cs-137 concentration of food materials can be identified below the maximum permissible concentration of 100 Bq/kg on a basis of the spectrum characteristic of Cs-137. Also, anxiety about radioactive contamination of foods after the Fukushima nuclear accident will be eased and trust of the radioactive inspection is expected definitely. (authors)

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2016

Cement Solidification of Residual Metal Oxide from Radioactive Waste

A lot of uranium contaminated soil and concrete waste is generated from the dismantlement of uranium conversion facilities. There are several disposal methods for radioactive materials such as regulation exemption, decontamination and long-term storage. It is necessary for us to achieve the permanent disposal of radioactive waste. The methods for solidifying radioactive waste include cement solidification, asphalt solidification, and polymer solidification. Cement solidification has several advantages such as well-known materials and technologies, various applications, and reasonable cost. On the contrary, it has certain disadvantages such as a large volume expansion of solidification for radioactive waste. Because cement solidification has excellent structural strength and a shielding effect, it is widely used for the permanent disposal of radioactive waste. Cement solidification operates as a barrier against the leaching of nuclides during radioactive waste disposal. To evaluate the criteria of KORAD (Korea Radioactive Waste Agency), integrity tests on the solidification of radioactive waste need to be performed. In this study, to inspect the criteria of KORAD, we carried out the cement solidification of residual metal oxide from radioactive waste. An integrity inspection such as the pressure strength, inundation, and leaching test on cement solidification was performed. We also analyzed the experimental results according to the criteria of KORAD. The calculation of the leachability index on the primary and secondary cement solidification for leaching detection of nuclides is carried out. The integrity of primary and secondary cement solidification is evaluated. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Development of the Mobile Systems for Conditioning of Disused Sealed Radioactive Sources in Serbia - 20105

Sealed radioactive sources (SRS) are being used worldwide in the field of medicine, agriculture, industry and research. They can be found in mobile as well as stationary devices. SRS contains radioactive material that is (a) permanently sealed in a capsule or (b) closely bounded and in a solid form. The capsule or material of an SRS should be strong enough to maintain leak tightness under the conditions of use and purpose for which the source was designed, also in case of accidents. In this case only emitted radiation is utilized. Firstly, the hazard from external radiation has to be considered, but the possibility of contamination due to fracture of the capsule should not be disregarded. The radioactive sources are composed of the radiating isotope contained in the filling medium, the single or double isotope holder that partially or totally surrounds the filling medium, the outer cover that contains the parts mentioned above and the capsule closed airtightly by welding or using some other method. The capsule must be tested for leakage periodically. If the SRS is no longer needed (e.g. replaced by a different technique) or it becomes useless for the intended application (e.g. the activity becomes too weak, the equipment containing the source works poorly or becomes obsolete, the source is damaged or leaking) it is considered disused. Disused sealed radioactive sources (DSRS) are typically conditioned and disposed if a facility is available. If the disposal option is not available, conditioned DSRS should be stored under proper conditions. In some cases, the radionuclide(s) in DSRS can be recovered/recycled or the DSRS can be repurposed for other applications. Conditioning of DSRS ensures containment of the radioactive material, provides confinement for leaking sources, provides sufficient radiation shielding, reduces storage/disposal volume by allowing consolidation of multiple sources into a single storage/disposal container, facilitates transport operations and contributes to safety and security as well. Typically, conditioning technologies are deployed either as permanently installed stationary systems in centralized or mobile on-site waste processing facilities, or in a mobile configuration. Centralized stationary facilities provide a single processing location for multiple users that requires transport of the waste to the facility. On the other hand, mobile systems may be provided for the selection and application of the optimum technology for a specific waste stream (such as DSRS) by bringing the process to the point where the waste is generated. In addition, mobile systems could offer additional flexibility by sharing equipment among multiple waste generating sites for processing campaigns that vary in duration, from very short periods to several years. The term 'mobile processing system' refers to any radioactive waste processing system or component which is designed to be transportable and which is not considered permanently installed. Two mobile system for conditioning of disused sealed radioactive sources are developed in the Public Company Nuclear Facilities of Serbia. Development of these mobile systems was supported by SRB9005 national project via Technical Cooperation of the IAEA. The first mobile system, built inside the 20 feet ISO container, will be used for conditioning of DSRS category 3 to 5. The second mobile system, built inside the 7 m long vehicle (Iveco Daily Van), will be used for dismantling of ionizing smoke detectors mostly with Am-241 sources. Designs of the mobile systems were defined in cooperation with two companies from Belgium (Belgoprocess and Leniko) and a Croatian company Ekoteh as well as with the support of the IAEA experts. The generic safety assessment and operational procedures for the mobile systems are developed. Based on safety assessment the acceptance criteria and operational limits and conditions are established. Operational procedures include: (a) equipment and material requirements, (b) assembling procedure of the mobile unit, (c) procedure for acceptance of devices for dismantling and conditioning, (d) dismantling procedure for devices to recover the DSRS, (e) characterization of DSRS, (f) encapsulation procedure of DSRS, (g) disassembling procedure of the mobile unit, and (h) keeping records, identification and traceability. In addition, radiation safety, health safety, security and emergency preparedness plans are prepared. The generic safety assessment and operational procedures could be updated with site specific requirements, DSRS inventory, and different needs for future customers. Developed mobile systems could be used in all situations when it is feasible to perform conditioning of DSRS on the spot in the county and worldwide. Development of these mobile units was just the first step to create the Reference Center for Radioactive Waste Treatment and Disused Radioactive Sources Conditioning for Small Facilities which can become a regional training center in the future, and/or as a tool for comprehensive national search and secure programmes. In the next phases development of e-learning platforms and blended learning packages as well as application for the IAEA Qualified Technical Centre (QTC) for the management of DSRS is foreseen. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

Conceptual Design of Decontamination System for Radioactive Contaminated Water with Microalgae

In 2011, Fukushima nuclear power plant accident in Japan caused contamination of lakes and rivers due to radioactive materials released. As time passes, the radioactivity of radioactive contaminated water has been lowered, but there is still some level of radioactive contamination. At present, decontamination of radioactive contaminated water uses a method of removing radioactive materials in polluted water by using resin or filter. This conventional decontamination method can lower the radioactive concentration of contaminated water to a certain level. However, it is difficult to reduce the amount of contaminated water to a level lower than the very low level due to technical and economic reasons. In this study, we propose a method to decontaminate water contaminated with radioactive materials using microalgae. In addition, a system for the treatment of radioactive contaminated water using microalgae has been conceptually designed.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Design and Development of an Automated Instrument for Measuring Radioactivity in an Excavator Bucket - 16246

Increasing interest and emphasis is being given to the presence of radioactive contamination in the environment and the methods by which this contamination can be remediated. Radioactive contamination may arise from industrial process including the operation of nuclear facilities. It may also arise from the enhancement of naturally occurring radioactive material by industrial processes. An area of particular concern is the remediation of soil and rubble with radioactive contamination. Traditional methods of soil remediation involve sampling followed by the excavation of areas where contamination is found. The soil removal process is normally very inefficient and can involve multiple handling of excessive quantities of soil and ultimately an over estimate of the quantity of soil with radioactive contamination. In order to both minimize material handling and to reduce the final volume of contaminated material, which must be handled for disposal, a sensitive instrument has been developed and tested which is designed to measure the radioactive content of an excavator bucket. The instrument detector is positioned automatically just above the open top of the bucket and the measurement employs a high efficiency sodium iodide crystal which has a graded shadow shield to reduce the effect of background radioactivity. The measurement efficiency is enhanced as the detector is located in close proximity to the soil in the bucket and the thick steel shell of the bucket acts as a shield to further reduce the effect of background from the ground below. The method has obvious advantages over methods, which attempt to measure the potentially radioactive soil through the shielding provided by the thick steel bucket shell. As the first stage of the bucket measurement the excavator operator fills the bucket and locates it in a designated position with the open top of the bucket facing upwards, close to the operator cab. A measurement technician, located outside the danger area of the excavator boom, begins the measurement using a tablet computer with a wireless connection to the instrument. The shielded detector is moved from a storage position above the operator cab to the measurement position close to the open surface of the excavator bucket. Once the measurement is completed in typically one to two minutes, the detector is repositioned in its storage location and the measurement data is transmitted to the tablet computer. At this point the measurement technician makes the decision based on the measurement results as to how to disposition the bucket contents. Typically contaminated material will be transferred to a vehicle for off-site disposal. Alternatively, and this is the great advantage of this technique, uncontaminated material may be returned directly to the site of the excavation without the need for further handling. The development, detailed design and preliminary testing of the instrument are described. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

The UK's National Policy and Programme for the Management of Spent Fuel and Radioactive Waste - 16574

This paper provides a broad overview of the United Kingdom's (UK's) national policies and national programme for the management of spent fuel and radioactive waste. The aim of the paper is to ensure a clear understanding of the approach taken in the UK so that opportunities for learning lessons and joint working, where they exist, can be identified and to ensure a general understanding of the interdependencies between the various approaches taken in the UK. With a legacy that dates back to the late 1940's/early 1950's the UK have a range of complex and difficult issues to resolve that have evolved over time. What was considered to be acceptable in the past is not thought of in the same way today. We therefore need to be forward thinking, innovative and above all ready to adapt our practices and policies to address previously unknown issues and complications. Due to the wide range of types of radioactive wastes and materials to be managed in the UK we have needed to establish a set of high level principles to cover all radioactive waste types while at the same time ensure that specific approaches for specific issues are developed within that framework. In the UK we have also had to consider the issue of integration to ensure that an approach that addresses one issue does not inadvertently cause a problem elsewhere - for example: in disposing of the high volumes of very low level waste we needed an approach to ensure that other low level waste has a disposal route. Financing of decommissioning and future waste management is clearly one of the biggest challenges to be addressed. As mentioned above ensuring that the legacy left for future generation is not one of a burden - we need to ensure that measures are in place to fund and manage long lived radioactive wastes. Finally, it is clear that not all radioactive wastes are the same and therefore different approaches are needed for managing the different types of material. This requires a proportionate and prioritised approach so while the same ultimate goal is applied (i.e.: the safe and responsible management of radioactive waste) some radioactive wastes are more equal than others and need to be treated accordingly. In the UK we believe that we have a broad programme in place that allows the right balance to be struck in managing all our radioactive waste and spent fuel in a proportionate, safe and responsible manner.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2014

Induced Radioactivity Analysis for the NSRL Linac in China Using Monte Carlo Simulations and Gamma Spectroscopy - Paper 141

The Synchrotron Radiation Facility of the National Synchrotron Radiation Laboratory (NSRL) located in Hefei, China consists of a 200-MeV electron linear accelerator and an 800-MeV electronic storage ring. Constructed in 1989, the 200-MeV Electron linac is one of the earliest high-energy electron linear accelerators in China. The NSRL is a large-scale experiment device, having been operated more than twenty years, so it is hard to give a historical recount about the injection of NSRL Linac. Lower-energy electrons emitted from the accelerator electron gun are progressively accelerated to about 200 MeV in five acceleration tubes, and then are injected into the electron storage ring, reaching the final energy of 800 MeV. The linear accelerator is a traveling wave linear accelerator, consisting of pre-injection, four 6-m acceleration segment, some beam sensing elements, and focusing inserts. The electrons are accelerated in the acceleration tubes to 32 MeV, 74 MeV, 116 MeV, 158 MeV, respectively, and the electronic energy reaches 200 MeV at the end of the acceleration trip. A scraper is used for beam collimation and is located at the end of each acceleration tube, with a length that increases with the energy to provide sufficient collimation. The NSRL Linac was retired in 2012 due to a plan to upgrade the facility. The decommissioning produced many real challenges related to the methods to handle the large size of the device and the time required to store structural materials until the radioactivity is reduced in the waste repository. These problems should be solved as soon as possible in order for the upgrade to proceed smoothly. At present, no prior decommissioning experience existed in China on such a high-energy electron linear accelerator. Therefore, the decommission project provided an opportunity to study and evaluate the challenges, in particular, involving the induced radioactivity for the purposes of radiation protection. For a well-shielded accelerator facility, the induced radioactivity is an important source of radiation for people who perform the decommissioning. In addition, information on the level of induced radioactivity is needed for disposing of the retired accelerator materials. Therefore it is significant to predict such radioactivity level accurately. However, the induced radioactivity study for such type high-energy electron linear accelerator is very seldom. Particle accelerators that operate at energy greater than 10 MeV will produce induced radioactivity due to well-known photonuclear interactions. However, the assessment of such as induced radioactivity of large-scale installations is a time-consuming process. Experimental methods are time-consuming and require special radiation safety measures to protection the investigators. On the other hand, empirical formula cannot yield sufficiently accurate results. Therefore, Monte Carlo simulation method is the primary means to study such problems. In the decommissioning process of the NSRL Linac, the induced radioactivity assessment will be based on Monte Carlo simulation method as the main auxiliary means to expand a series of studies. (authors)

43 PARTICLE ACCELERATORS↗
DOE OSTI2017

Innovative Solutions To Solve Complex Radioactive Waste Management Problems In The U.S. - 2017 Richard S. Hodes, M.D. Honor Lecture Award - 17609

Ever since Wilhelm Roentgen, Henri Becquerel, and Marie Curie discovered x-rays, radioactivity, and radium, respectively, at the turn of the nineteenth century, nuclear technologies have continued to evolve and significantly enrich the quality of life for mankind. The evolution of such technologies has enabled our society to diagnose medical illnesses without the need for invasive surgeries, treat cancers, conduct research, develop new kinds of pharmaceuticals, preserve our food supply, and generate over 20% of our nation's electricity from commercial nuclear power plants. While these life-changing technologies have significantly enriched our quality of life and advanced our understanding of the sciences, they also generate radioactive waste that must be managed responsibly in a manner that protects public health. Over the past several decades, decision makers have developed a patchwork of policies to safely manage radioactive wastes-policies that are not necessarily based on the risk posed to public health, but more often on the origins of the waste and the manner in which they are defined in federal legislation. However, in the past several years, much progress has been made to better risk-inform the practices of managing Low-Level Radioactive Waste (LLW) in the United States. In 2012, the nation's first regional commercial facility for disposing of Class A, B, and C LLW since the U.S. Congress enacted the Low-Level Radioactive Waste Policy Act of 1980, as amended in 1985, was opened in Andrews County, Texas. Since then, other innovative LLW management solutions have emerged, ranging from cost-effective disposal options for wastes with very low levels of radioactivity to depleted uranium, and perhaps ultimately, for waste exceeding the concentration-based limits for Class C LLW (i.e., Greater Than Class C LLW) as specified in Title 10 of the Code of Federal Regulations (CFR), chap. 61.55. Most recently, a license application for a consolidated interim storage facility for Spent Nuclear Fuel (SNF) is currently under review by the U.S. Nuclear Regulatory Commission (NRC). Should the NRC approve the license application, SNF currently located at 12 shutdown and decommissioned nuclear reactors could be placed into interim storage in Texas. Approval of this license application would facilitate the complete decommissioning of nuclear power plants, returning them to green-fields, and allowing the local communities to re-purpose the lands for further economic development. Over the next decade, many of these waste management challenges that once seemed insurmountable may soon be transformed into a reality. As will be discussed at the award lecture, achieving such possibilities clearly aligns with the vision of creating innovative radioactive waste management solutions for our nation that were championed by the late physician and statesman, Dr. Richard S. Hodes. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Experience with the Quality Control of Radioactive Waste Packages for the German Repository Konrad - 16493

The German repository Konrad for radioactive waste with negligible heat generation is designed to accept 303,000 m{sup 3} of waste packages in total. Based on the Konrad licensing conditions, any treatment and conditioning of radioactive waste should be planned and carried out in accordance with the waste acceptance requirements of the repository Konrad in order to produce waste packages suitable for disposal. The qualification of the waste treatment processes and the resulting products are achieved by interaction of different parties involved. On behalf of the Federal Office for Radiation Protection - the competent German authority for disposal of radioactive waste - TUV NORD EnSys Hannover GmbH and Co. KG acts as one of the independent expert organizations for more than twenty years in the field of qualification of waste treatment campaigns and review of waste packages documentations. The permitted amount of nuclide activity in the radioactive waste packages depends on the characteristics of the radioactive waste products. Projecting a suitable strategy for loading the waste containers contributes to determine in advance, what requirements the radioactive waste products have to fulfill as well as what properties of the waste products need to be verified and documented during conditioning or treatment process. On the basis of various examples, it is being demonstrated how appropriate advance process planning can ensure that radioactive waste packages are generated to comply with the waste acceptance requirements. In consequence, technical measures due to requalification can be avoided even in case of unpredictable difficulties. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Issues and Challenges for the Disposal of Solid Radioactive Waste in the UK - 16597

The latest UK radioactive waste inventory describes the UK as having roughly 4.5 million m{sup 3} of solid radioactive waste - waste that either exists now or which will arise in future. This quantity excludes the potential waste that could be generated from the final site clearance of nuclear sites, estimated to be at least 3 times the current inventory volume. Most solid radioactive waste (by volume) is managed in the near-surface, at the national Low Level Waste Repository (LLWR) or in other appropriately permitted landfill sites. The UK has yet to develop solutions for the final disposal of Higher Activity Radioactive Waste (HAW) but has established arrangements for packaging of waste now for storage while maximising the probability that these packages will be disposable once a solution is provided. Irrespective of the final disposal solution, the principles that govern the safe management of solid radioactive waste are common across the UK. Recent experience in the UK, including from the review of the environmental safety case for the LLWR, identified a number of issues relevant to solid waste disposal which are pertinent to other existing Low Activity Radioactive Waste (LAW) disposal sites as well as the development of safety cases for HAW disposal facilities. These issues include: scoping the extent of 'wastes' included in any assessment (e.g. whether to include the 'package' as well as its contents); the importance of understanding the waste heterogeneity; non-radioactive characteristics of waste, and understanding of external factors such as climate and landscape change. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2022

Charging of radioactive and environmental airborne particles

The charging of various airborne particles was investigated using single-particle levitation and charge-balance equations. Though radioactive decay and triboelectrification can induce charging, it is typically assumed that the aerosols in a radioactive plume will not carry significant charge at steady state since atmospheric particles can have their charge neutralized through the capture of adjacent counter-ions (i.e., diffusion charging). Here to assess this assumption, we directly measured the surface charge and charge density of various triboelectrically charged aerosols including radioactive uranium oxide (<1 μm), urban dust, Arizona desert dust, hydrophilic and hydrophobic silica nanoparticles, and graphene oxide powders using an electric field-assisted particle levitator in air. Of these particles, uranium oxide aerosols exhibited the highest surface charge density. Charge balance equations were employed to predict the average charge gained from radioactive decay as a function of time and to evaluate the effects of diffusion charging on triboelectrically charged radioactive and non-radioactive particles in the atmosphere. Simulation results show that particles, initially charged through triboelectrification, can be quickly discharged by diffusion charging in the absence of radioactive decay. Nevertheless, simulation results also indicate that particles can be strongly charged when they carry radionuclides. These experimental and simulation results suggest that radioactive decay can induce strong particle charging that may potentially affect atmospheric transport of airborne radionuclides.

54 ENVIRONMENTAL SCIENCES↗