Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “RADIOACTIVE”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Study on Gaseous and Liquid Radioactive Effluents in AP1000 Plants

During normal operation, the gaseous and liquid radioactive effluents will be released in nuclear plants. It is the base of effluents management and environment influence evaluation to analyze the anticipated annual activity releases. In China, both the annual release of radioactive liquid and gaseous effluents limit value (for single plant and whole-site) and the liquid concentration of discharge canal are introduced in GB6249-2011. This standard is mandatory and the limit values must be met. Because the limit values are very strict, it is meaningful to determine a suitable and logical method of liquid and gaseous effluents in China. In this paper, according to the operation actuality and related rules of law in China, the analysis method of nuclides except H-3 and C-14 in the gaseous and liquid effluents of AP1000 plant is introduced. The method and results can be reference for effluents analysis for AP1000 plants. According to the revised method, the gaseous and liquid radioactive effluents for Sanmen 1 and 2 plants are calculated. The results and the comparison with the limit value in GB6249-2011 are given. The liquid concentration of discharge canal is 868.4 Bq/l, which is less than the limit value 1000 Bq/L in GB6249-2011. It can be seen that according to the revised method, the gaseous and liquid radioactive effluents for Sanmen 1 and 2 plants can meet the limit value in GB6249-2011. This revised method considers all the source, the detailed purification process and release pathways for gaseous and liquid radioactive effluents. The effluents calculation in the revised method can be a possible reference to the analysis of the gaseous and liquid radioactive effluents in China, though there may be some detailed optimization and improvement in future. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2014

A Low-Tech, Low-Budget Storage Solution for High Level Radioactive Sources

The need for safe, secure, and economical storage of radioactive material becomes increasingly important as beneficial uses of radioactive material expand (increases inventory), as political instability rises (increases threat), and as final disposal and treatment facilities are delayed (increases inventory and storage duration). Several vendor-produced storage casks are available for this purpose but are often costly — due to the required design, analyses, and licensing costs. Thus the relatively high costs of currently accepted storage solutions may inhibit substantial improvements in safety and security that might otherwise be achieved. This is particularly true in areas of the world where the economic and/or the regulatory infrastructure may not provide the means and/or the justification for such an expense. This paper considers a relatively low-cost, low-technology radioactive material storage solution. The basic concept consists of a simple shielded storage container that can be fabricated locally using a steel pipe and a corrugated steel culvert as forms enclosing a concrete annulus. Benefits of such a system include 1) a low-tech solution that utilizes materials and skills available virtually anywhere in the world, 2) a readily scalable design that easily adapts to specific needs such as the geometry and radioactivity of the source term material), 3) flexible placement allows for free-standing above-ground or in-ground (i.e., below grade or bermed) installation, 4) the ability for future relocation without direct handling of sources, and 5) a long operational lifetime . ‘Le mieux est l’ennemi du bien’ (translated: The best is the enemy of good) applies to the management of radioactive materials – particularly where the economic and/or regulatory justification for additional investment is lacking. Development of a low-cost alternative that considerably enhances safety and security may lead to a greater overall risk reduction than insisting on solutions that remain economically and/or politically ‘out of reach’.

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

Sixth National Report for the Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management

The United States of America (U.S.) ratified the Joint Convention on the Safety of Spent Fuel Management and on the Safety of Radioactive Waste Management (Joint Convention) on April 9, 2003. The Joint Convention establishes an international peer review process among Contracting Parties and provides incentives for nations to take appropriate steps to bring their spent fuel and radioactive waste management activities into compliance with general safety standards and practices. An extensive U.S. legal and regulatory structure ensures the safety of spent fuel and radioactive waste management. This report describes radioactive waste management in the U.S. in both the commercial and government sectors, and provides annexes with information on spent fuel and waste management facilities, inventories, and ongoing decommissioning projects. It also provides detailed information on spent fuel and radioactive waste management safety, as well as transboundary movements (imports/exports) and disused sealed sources, as required by the Joint Convention.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2012

Principles of Product Quality Control of German Radioactive Waste Forms from the Reprocessing of Spent Fuel: Vitrification, Compaction and Numerical Simulation - 12529

The German product quality control is inter alia responsible for control of two radioactive waste forms of heat generating waste: a) homogeneous vitrified HLW and b) heterogeneous compacted hulls, end-pieces and technological metallic waste. In either case, significantly different metrology is employed at the site of the conditioning plant for the obligatory nuclide inventory declaration. To facilitate an independent evaluation and checking of the accompanying documentation numerical simulations are carried out. The physical and chemical properties of radioactive waste residues are used to assess the data consistency and uncertainty margins, as well as to predict the long-term behavior of the radioactive waste. This is relevant for repository acceptance and safety considerations. Our new numerical approach follows a bottom-up simulation starting from the burn-up behavior of the fuel elements in the reactor core. The output of these burn-up calculations is then coupled with a program that simulates the material separation in the subsequent dissolution and extraction processes normalized to the mass balance. Follow-up simulations of the separated reprocessing lines of a) the vitrification of highly-active liquid and b) the compaction of residual intermediate-active metallic hulls remaining after fuel pellets dissolution, end-pieces and technological waste, allows calculating expectation values for the various repository relevant properties of either waste stream. The principles of the German product quality control of radioactive waste residues from the spent fuel reprocessing have been introduced and explained. Namely, heat generating homogeneous vitrified HLW and heterogeneous compacted metallic MLW have been discussed. The advantages of a complementary numerical property simulation have been made clear and examples of benefits are presented. We have compiled a new program suite to calculate the physical and radio-chemical properties of common nuclear waste residues. The immediate benefit is the independent assessment of radio-active inventory declarations and much facilitated product quality control of waste residues that need to be returned to Germany and submitted to a German HLW-repository requirements. Wherever possible, internationally accepted standard programs are used and embedded. The innovative coupling of burn-up calculations (SCALE) with neutron and gamma transport codes (MCPN-X) allows an application in the world of virtual waste properties. If-then-else scenarios of hypothetical waste material compositions and distributions provide valuable information of long term nuclide property propagation under repository conditions over a very long time span. Benchmarking the program with real residue data demonstrates the power and remarkable accuracy of this numerical approach, boosting the reliability of the confidence aforementioned numerous applications, namely the proof tool set for on-the-spot production quality checking and data evaluation and independent verification. Moreover, using the numerical bottom-up approach helps to avoid the accumulation of fake activities that may gradually build up in a repository from the so-called conservative or penalizing nuclide inventory declarations. The radioactive waste properties and the hydrolytic and chemical stability can be predicted. The interaction with invasive chemicals can be assessed and propagation scenarios can be developed from reliable and sound data and HLW properties. Hence, the appropriate design of a future HLW repository can be based upon predictable and quality assured waste characteristics. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2012

Stakeholder Engagement on the Environmental Impact Statement for the Disposal of Greater-Than-Class C Low-Level Radioactive Waste -12565

The Department of Energy's (DOE) Office of Disposal Operations is responsible for developing a permanent disposal capability for a small volume, but highly radioactive, class of commercial low-level radioactive waste, known as Greater-Than-Class C (GTCC) low-level radioactive waste. DOE has issued a draft environmental impact statement (EIS) and will be completing a final EIS under the National Environmental Policy Act (NEPA) that evaluates a range of disposal alternatives. Like other classes of radioactive waste, proposing and evaluating disposal options for GTCC waste is highly controversial, presents local and national impacts, and generates passionate views from stakeholders. Recent national and international events, such as the cancellation of the Yucca Mountain project and the Fukushima Daiichi nuclear accident, have heighten stakeholder awareness of everything nuclear, including disposal of radioactive waste. With these challenges, the Office of Disposal Operations recognizes that informed decision-making that will result from stakeholder engagement and participation is critical to the success of the GTCC EIS project. This paper discusses the approach used by the Office of Disposal Operations to engage stakeholders on the GTCC EIS project, provides advice based on our experiences, and proffers some ideas for future engagements in today's open, always connected cyber environment. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2013

Safety and security of radioactive sources in industrial radiography in Bangladesh

Malicious use of radioactive sources can involve dispersal of that material through an explosive device. There has been recognition of the threat posed by the potential malicious misuse of NDT radioactive source by terrorists. The dispersal of radioactive material using conventional explosives, referred to as a 'dirty bomb', could create considerable panic, disruption and area access denial in an urban environment. However, as it is still a relatively new topic among regulators, users, and transport and storage operators worldwide, international assistance and cooperation in developing the necessary regulatory and security infrastructure is required. The most important action in reducing the risk of radiological terrorism is to increase the security of radioactive sources. This paper presents safety and security considerations for the transport and site storage of the industrial radiography sources as per national regulations entitled 'Nuclear Safety and Radiation Control Rules-1997'.The main emphasis was put on the stages of some safety and security actions in order to prevent theft, sabotage or other malicious acts during the transport of the packages. As a conclusion it must be mentioned that both safety and security considerations are very important aspects that must be taking in account for the transport and site storage of radioactive sources used in the practice of industrial radiography. (authors)

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2016

Radioactive Waste Water Treatment for Fukushima Daiichi Nuclear Power Plant - 16081

The Great East Japan Earthquake of 11 March 2011 caused serious damage to the Fukushima Daiichi Nuclear Power Station (NPS) of the Tokyo Electric Power Company, Inc.. Toshiba and Shaw/AVANTech installed a Simplified Active Water Retrieve and Recovery System (SARRY{sup TM}) to remove radioactive cesium (Cs) from the contaminated water. Toshiba, in partnership with EnergySolutions, also developed and installed the Multi Radionuclide Removal System (MRRSTM), which can remove radioactive nuclides being treated, except tritium, to a level less than the concentration limit in water. As contaminated water treatment has progressed, the composition of the contaminated water has changed. Both salinity and radioactive Cs concentration in the contaminated water have been decreasing. Thus, a new adsorbent that is suitable for the present water chemistry conditions is required. In order to provide an appropriate contaminated-water treatment system, Toshiba has been examining the removal of not only radioactive Cs but also radioactive strontium (Sr) by SARRY{sup TM}. SARRY{sup TM} has been operated for removing Cs by using a Cs adsorbent. Instead of a Cs adsorbent, a new media that has high selectivity for both Cs and Sr should be installed. This paper describes the results obtained when using the newly developed adsorbent for removing Cs and Sr at once. As the Cs and Sr adsorbent, we have selected crystalline silico-titanate (CST). The distribution coefficient (K{sub d}) of CST was determined by the batch method. The lifetime of the adsorbent was evaluated by a column examination. The selected CST had a K{sub d} value of over 10{sup 4} ml/g for both Cs and Sr. The highest-selectivity CST had a lifetime (defined as the period for the outlet concentration to decrease to one tenth of the inlet level) of more than 125000 BV (bed volume) for Cs and more than 18000 BV for Sr, when the test was conducted at 10 BV/h. Calculation code was also developed for estimating the relation between the BV and the decontamination factor (DF) using an adsorption rate model for diffusion and adsorption. The calculation results of the Cs and Sr adsorption behavior agreed well with the experimental results. To evaluate the replacement cycle of adsorption tower in actual equipment, the radiation exposure during the replacement operation and the required Cs and Sr removal performance were used as limiting conditions for the estimation. The results of the evaluation showed that the selected CST has sufficient performance for practical usage. Based on this finding, Toshiba proposed loading the CST in SARRY{sup TM}, and SARRY{sup TM} loaded with this CST started removing Cs and Sr in December 2014 resulting in decreased contaminated water. It has been continuously working since then. (authors)

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

Regulatory Treatment of Non-Core Sources of Radioactivity for Advanced Reactor Designs

The recent resurgence in advance (non-light water) reactor development has been paralleled by the development of risk-informed performance-based (RIPB) licensing pathways. Specifically, the creation of the RIPB Licensing Modernization Project (LMP) approach and subsequent endorsement by the U.S. Nuclear Regulatory Commission (NRC) now provides advanced reactor vendors with a defined RIPB method to develop an affirmative safety case for licensing. In addition, the Technology Inclusive Content of Applications Project (TICAP) has published guidance on developing a license application based on the LMP approach. To support the utilization of risk information as part of advanced reactor design and licensing efforts, the American Society of Mechanical Engineers (ASME)/American Nuclear Society (ANS) Joint Committee on Nuclear Risk Management (JCNRM) has developed a probabilistic risk assessment (PRA) standard for advanced reactors. The standard, which was formerly approved by the American National Standards Institute (ANSI) in 2021 and recently endorsed by the NRC in trial use Regulatory Guide (RG) 1.247, is an integral standard, covering from initiating events to offsite consequence. A major feature of the standard is that it permits the inclusion of any source of radioactivity material at the site within the plant PRA. Therefore, non-core sources of radioactivity, such as fuel storage, fuel processing, and purification systems, can be included within a single comprehensive plant PRA. For those advanced reactor vendors utilizing a RIPB licensing approach, there is an opportunity to include the non-core sources of radioactivity within the RIPB framework for licensing decision-making, such as the categorization of events, classification of structures, systems, and components (SSCs), and evaluation of the adequacy of defense-in-depth (DID). For advanced reactor designs that contain multiple non-core sources of radioactivity, or for monolithic plant sites that include associated fuel facilities, this approach could potentially simplify licensing applications through the use of a single, uniform, and consistent decision-making framework across all radioactive sources at the site. In addition, a RIPB approach could provide additional insights regarding plant behavior, flexibility regarding licensing decision-making, and potentially allow the use of risk information as part of the plant oversight process. Risk-informing these aspects of advanced reactor licensing would also be consistent with the NRC’s risk policy statement. However, there is diverse regulation and guidance regarding the licensing of non-core sources of radioactivity and generally limited experience using RIPB approaches for the evaluation as part of licensing.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2015

Study of two different radioactive sources for prostate brachytherapy treatment

In this study we evaluated two radioactive sources for brachytherapy treatments. Our main goal was to quantify the absorbed doses on organs and tissues of an adult male patient, submitted to a brachytherapy treatment with two radioactive sources. We evaluated a {sup 192}Ir and a {sup 125}I radioactive sources. The {sup 192}Ir radioactive source is a cylinder with 0.09 cm in diameter and 0.415 cm long. The {sup 125}I radioactive source is also a cylinder, with 0.08 cm in diameter and 0.45 cm long. To evaluate the absorbed dose distribution on the prostate, and other organs and tissues of an adult man, a male virtual anthropomorphic phantom MASH, coupled in the radiation transport code MCNPX 2.7.0, was employed.We simulated 75, 90 and 102 radioactive sources of {sup 125}I and one of {sup 192}Ir, inside the prostate, as normally used in these treatments, and each treatment was simulated separately. As this phantom was developed in a supine position, the displacement of the internal organs of the chest, compression of the lungs and reduction of the sagittal diameter were all taken into account. For the {sup 192}Ir, the higher doses values were obtained for the prostate and surrounding organs, as the colon, gonads and bladder. Considering the {sup 125}I sources, with photons with lower energies, the doses to organs that are far from the prostate were lower. All values for the dose rates are in agreement with those recommended for brachytherapy treatments. Besides that, the new seeds evaluated in this work present usefulness as a new tool in prostate brachytherapy treatments, and the methodology employed in this work may be applied for other radiation sources, or treatments. (authors)

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2017

1st Quarter Transportation Report FY2017: Waste Shipments To and From the Nevada National Security Site (NNSS), Radioactive Waste Management Complex

This report satisfies the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office (NNSA/NFO) commitment to prepare a quarterly summary report of waste shipments to the Nevada National Security Site (NNSS) Radioactive Waste Management Complex (RWMC) at Area 5. This report summarizes the 1st quarter of fiscal year (FY) 2017 low-level radioactive waste (LLW), mixed low-level radioactive waste (MLLW) and classified non-radioactive (CNR) shipments. There were no shipments sent for offsite treatment from a NNSS facility and returned to the NNSS this quarter of FY2017.

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

2nd Quarter Transportation Report FY2015: Radioactive Waste Shipments to and from the Nevada National Security Site

This report satisfies the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Field Office (NNSA/NFO) commitment to prepare a quarterly summary report of radioactive waste shipments to and from the Nevada National Security Site (NNSS) Radioactive Waste Management Complex (RWMC) at Area 5. There were no shipments sent for offsite treatment and returned to the NNSS this quarter. This report summarizes the 2nd quarter of Fiscal Year (FY) 2015 low-level radioactive waste (LLW) and mixed low-level radioactive waste (MLLW) shipments.

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

Radiation Safety of Sealed Radioactive Sources

Sealed radioactive sources are used in a wide variety of occupational settings and under differing regulatory/licensing structures. The definition of a sealed radioactive source varies between US regulatory authorities and standard-setting organizations. Potential problems with sealed sources cover a range of risks and impacts. The loss of control of high activity sealed sources can result in very high or even fatal doses to members of the public who come in contact with them. Sources that are not adequately sealed, and that fail, can cause spread of contamination and potential intake of radioactive material. There is also the possibility that sealed sources may be (or threatened to be) used for terrorist purposes and disruptive opportunities. Until fairly recently, generally-licensed sealed sources and devices received little, if any, regulatory oversight, and were often forgotten, lost or unaccounted for. Nonetheless, generally licensed devices can contain fairly significant quantities of radioactive material and there is some potential for exposure if a device is treated in a way that it was never designed. Industrial radiographers use and handle high activity and/or high-dose rate sealed sources in the field with a high degree of independence and minimal regulatory oversight. Failure to follow operational procedures and properly handle radiography sources can and has resulted in serious injuries and death. Industrial radiographers have experienced a disproportionately large fraction of incidents that result in unintended exposure to radiation. Sources do not have to contain significant quantities of radioactive material to cause problems in the event of their failure. A loss of integrity can cause the spread of contamination and potential exposure to workers and members of the public. The NCRP has previously provided recommendations on select aspects of sealed source programs. Future efforts to provide recommendations for sealed source programs are discussed.

radioactive material↗
DOE OSTI2019

Waste Shipments to and from the Nevada National Security Site (NNSS) Radioactive Waste Management Complex, FY19 First Quarter Transportation Report

This report satisfies the U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office (NNSA/NFO) commitment to prepare a quarterly summary of waste shipments to the Nevada National Security Site (NNSS) Radioactive Waste Management Complex (RWMC) in Area 3 and Area 5. This report summarizes the first quarter of fiscal year (FY) 2019 and serves as a quarterly report for the following types of shipments: Low-Level Radioactive Waste (LLW) Mixed Low-Level Radioactive Waste (MLLW) Classified Non-Radioactive (CNR) Waste Classified Non-Radioactive Hazardous (CNRH) Waste

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

4th Quarter / Annual Transportation Report FY2017: Waste Shipments To and From the Nevada National Security Site (NNSS), Radioactive Waste Management Complex

This report satisfies the U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office commitment to prepare a quarterly summary report of waste shipments to the Nevada National Security Site (NNSS) Radioactive Waste Management Complex at Area 5. This report summarizes the 4th quarter of fiscal year (FY) 2017 low-level radioactive waste (LLW), mixed low-level radioactive waste (MLLW), which includes classified LLW and MLLW, classified non-radioactive and classified non-radioactive hazardous shipments. There were no shipments sent for offsite treatment from an NNSS facility and returned to the NNSS this quarter of FY2017.

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

Waste Shipments to and from the Nevada National Security Site (NNSS), Radioactive Waste Management Complex (Q4 and Annual Transportation Report (FY 2019)

This report satisfies the U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office commitment to prepare a quarterly summary of waste shipments to the Nevada National Security Site Radioactive Waste Management Complex in Area 3 and Area 5. This report summarizes the fourth quarter of fiscal year 2019 and serves as an annual report for the following types of shipments: Low-Level Radioactive Waste, Mixed Low-Level Radioactive Waste, Classified Non-Radioactive Waste, Classified Non-Radioactive Hazardous Waste.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2012

Apparatus and method for radioactive waste screening

An apparatus and method relating to screening radioactive waste are disclosed for ensuring that at least one calculated parameter for the measurement data of a sample falls within a range between an upper limit and a lower limit prior to the sample being packaged for disposal. The apparatus includes a radiation detector configured for detecting radioactivity and radionuclide content of the of the sample of radioactive waste and generating measurement data in response thereto, and a collimator including at least one aperture to direct a field of view of the radiation detector. The method includes measuring a radioactive content of a sample, and calculating one or more parameters from the radioactive content of the sample.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2012

Radioactive Waste Conditioning, Immobilisation, And Encapsulation Processes And Technologies: Overview And Advances (Chapter 7)

The main immobilization technologies that are available commercially and have been demonstrated to be viable are cementation, bituminization, and vitrification. Vitrification is currently the most widely used technology for the treatment of high level radioactive wastes (HLW) throughout the world. Most of the nations that have generated HLW are immobilizing in either alkali borosilicate glass or alkali aluminophosphate glass. The exact compositions of nuclear waste glasses are tailored for easy preparation and melting, avoidance of glass-in-glass phase separation, avoidance of uncontrolled crystallization, and acceptable chemical durability, e.g., leach resistance. Glass has also been used to stabilize a variety of low level wastes (LLW) and mixed (radioactive and hazardous) low level wastes (MLLW) from other sources such as fuel rod cladding/decladding processes, chemical separations, radioactive sources, radioactive mill tailings, contaminated soils, medical research applications, and other commercial processes. The sources of radioactive waste generation are captured in other chapters in this book regarding the individual practices in various countries (legacy wastes, currently generated wastes, and future waste generation). Future waste generation is primarily driven by interest in sources of clean energy and this has led to an increased interest in advanced nuclear power production. The development of advanced wasteforms is a necessary component of the new nuclear power plant (NPP) flowsheets. Therefore, advanced nuclear wasteforms are being designed for robust disposal strategies. A brief summary is given of existing and advanced wasteforms: glass, glass-ceramics, glass composite materials (GCM’s), and crystalline ceramic (mineral) wasteforms that chemically incorporate radionuclides and hazardous species atomically in their structure. Cementitious, geopolymer, bitumen, and other encapsulant wasteforms and composites that atomically bond and encapsulate wastes are also discussed. The various processing technologies are cross-referenced to the various types of wasteforms since often a particular type of wasteform can be made by a variety of different processing technologies.

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

Considerations Related To Human Intrusion In The Context Of Disposal Of Radioactive Waste-The IAEA HIDRA Project

The principal approaches for management of radioactive waste are commonly termed ‘delay and decay’, ‘concentrate and contain’ and ‘dilute and disperse’. Containing the waste and isolating it from the human environment, by burying it, is considered to increase safety and is generally accepted as the preferred approach for managing radioactive waste. However, this approach results in concentrated sources of radioactive waste contained in one location, which can pose hazards should the facility be disrupted by human action in the future. The International Commission on Radiological Protection (ICRP), International Atomic Energy Agency (IAEA), and Organization for Economic Cooperation and Development/Nuclear Energy Agency (OECD/NEA) agree that some form of inadvertent human intrusion (HI) needs to be considered to address the potential consequences in the case of loss of institutional control and loss of memory of the disposal facility. Requirements are reflected in national regulations governing radioactive waste disposal. However, in practice, these requirements are often different from country to country, which is then reflected in the actual implementation of HI as part of a safety case. The IAEA project on HI in the context of Disposal of RadioActive waste (HIDRA) has been started to identify potential areas for improved consistency in consideration of HI. The expected outcome is to provide recommendations on how to address human actions in the safety case in the future, and how the safety case may be used to demonstrate robustness and optimize siting, design and waste acceptance criteria within the context of a safety case.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗