Y. Y. Liu

Advanced Surveillance Technologies for Used Fuel Long-Term Storage and Transportation

Utilities worldwide are using dry-cask storage systems to handle the ever-increasing number of discharged fuel assemblies from nuclear power plants. In the United States and possibly elsewhere, this trend will continue until an acceptable disposal path is established. The recent Fukushima nuclear power plant accident, specifically the events with the storage pools, may accelerate the drive to relocate more of the used fuel assemblies from pools into dry casks. Many of the newer cask systems incorporate dual-purpose (storage and transport) or multiple-purpose (storage, transport, and disposal) canister technologies. With the prospect looming for very long term storage — possibly over multiple decades — and deferred transport, condition- and performance-based aging management of cask structures and components is now a necessity that requires immediate attention. From the standpoint of consequences, one of the greatest concerns is the rupture of a substantial number of fuel rods that would affect fuel retrievability. Used fuel cladding may become susceptible to rupture due to radial-hydride-induced embrittlement caused by water-side corrosion during the reactor operation and subsequent drying/transfer process, through early stage of storage in a dry cask, especially for high burnup fuels. Radio frequency identification (RFID) is an automated data capture and remote-sensing technology ideally suited for monitoring sensitive assets on a long-term, continuous basis. One such system, called ARG-US, has been developed by Argonne National Laboratory for the U.S. Department of Energy’s Packaging Certification Program for tracking and monitoring drums containing sensitive nuclear and radioactive materials. The ARG-US RFID system is versatile and can be readily adapted for dry-cask monitoring applications. The current built-in sensor suite consists of seal, temperature, humidity, shock, and radiation sensors. With the universal asynchronous receiver/transmitter interface in the tag, other sensors can be easily added as needed. The system can promptly generate alarms when any of the sensor thresholds are violated. For performance and compliance records, the ARGUS RFID tags incorporate nonvolatile memories for storing sensory data and history events. Over the very long term, to affirmatively monitor the condition of the cask interior (particularly the integrity of cover gas and fuel-rod cladding), development of enabling technologies for such monitoring would be required. These new technologies may include radiation-hardened sensors, in-canister energy harvesting, and wireless means of transmitting the sensor data out of the canister/cask.Copyright

Monitoring Helium Integrity in Welded Canisters

Monitoring the interior of a welded canister containing spent (or used) nuclear fuel for its functional and structural integrity is exceptionally challenging because of the intense levels of heat and radiation and the difficulties of transmitting the sensor signals out through the sealed stainless-steel canister wall. Yet, confirmation of canister integrity is crucial for the aging management of the dry cask storage systems (DCSSs) for extended long-term storage and subsequent transportation of used fuel. A canister breach can lead to serious consequences — release of radioactive contaminants; oxidation of fuel cladding, which could compromise fuel rod integrity and criticality safety; and generation of potentially explosive hydrogen gas. The development of the Remote Area Modular Monitoring (RAMM) technology and 3D simulation of thermal performance of a vertical dry storage cask are reported in this paper, as is a preliminary plan for field-testing and evaluation of multiple prototype RAMM units on selected dry storage casks at an Independent Spent Fuel Storage Installation (ISFSI) site.Copyright

RFID Technology for Environmental Remediation and Radioactive Waste Management

An advanced Radio Frequency Identification (RFID) system capable of tracking and monitoring a wide range of materials and components—from fissionable stocks to radioactive wastes—has been developed. The system offers a number of advantages, including enhanced safety, security and safeguards, reduced personnel exposure to radiation, and improved inventory control and cost-effectiveness. Using sensors, RFID tags can monitor the state of health of the tracked items and trigger alarms instantly when the normal ranges are violated. Nonvolatile memories in the tags can store sensor data, event records, as well as a contents manifest. Gamma irradiation tests showed that the tag components possess significant radiation resistance. Long-life batteries and smart management circuitries permit the tags to operate for up to 10 years without battery replacement. The tags have a near universal form factor, i.e., they can fit different package types. The read range is up to >100 m with no line-of-sight required. With careful implementation, even a large-size processing or storage facility with a complex configuration can be monitored with a handful of readers in a network. In transportation, by incorporating Global Positioning System (GPS), satellite/cellular communication technology, and secure Internet, situation awareness is assured continuously. The RFID system, when integrated with Geographic Information System (GIS) technology, can promptly provide content- and event-specific information to first responders and emergency management teams in case of incidents. In stand-alone applications, the monitoring and tracking data are contained within the local computer. With a secure Internet, information can be shared within the complex or even globally in real time. As with the deployment of any new technology, overcoming the cultural resistance is part of the developmental process. With a strong institutional support and multiple successful live demonstrations, the cultural resistance has been mostly overcome. As a result, implementation of the RFID technology is taking place at several of U.S. Department of Energy sites and laboratories for processing, storage, and transportation applications.Copyright

Demonstration (DEMO) of radiofrequency identification (RFID) system for tracking and monitoring of nuclear materials

Abstract The US Department of Energy (DOE) [Environmental Management (EM), Office of Packaging and Transportation (EM-45)] Packaging Certification Program (PCP) has developed a radiofrequency identification (RFID) tracking and monitoring system for the management of nuclear materials packages during storage and transportation. The system, developed by the PCP team at Argonne National Laboratory, involves hardware modification, application software development, secured database and web server development, and irradiation experiments. In April 2008, Argonne tested key features of the RFID tracking and monitoring system in a weeklong, 1700 mile (2736 km) demonstration employing 14 empty type B fissile material drums of three designs (models 9975, 9977 and ES-3100) that have been certified for shipment by the DOE and the US Nuclear Regulatory Commission. The demonstration successfully integrated global positioning system (GPS) technology for vehicle tracking, satellite/cellular (general packet radio service, or GPRS) technologies for wireless communication, and active RFID tags with multiple sensors (seal integrity, shock, temperature, humidity and battery status) on drums. In addition, the demonstration integrated geographic information system (GIS) technology with automatic alarm notifications of incidents and generated buffer zone reports for emergency response and management of staged incidents. The demonstration was sponsored by EM and the US National Nuclear Security Administration, with the participation of Argonne, Savannah River and Oak Ridge National Laboratories. Over 50 authorised stakeholders across the country observed the demonstration via secured Internet access. The DOE PCP and national laboratories are working on several RFID system implementation projects at selected DOE sites, as well as continuing device and systems development and widening applications beyond DOE sites and possibly beyond nuclear materials to include other radioactive materials.

Extending intervals for periodic leakage rate testing of radioactive material transportation packagings

Abstract This paper describes methodologies that may be used to extend the intervals applied to the periodic leakage rate testing of certified type B transportation packagings that are loaded but not immediately shipped. In some cases, the packagings may be held in interim storage for more than 1 year, and the immediate goal is to extend the leakage rate testing interval from 1 up to as many as 5 years. The extended intervals are predicated on the basis of acceptable results of long term O ring performance tests and continuous monitoring of environmental conditions of the packagings provided by the ARG-US radio frequency identification (RFID) system. Preliminary results obtained from field testing and applications of the ARG-US RFID system to date indicated that the system is reliable and that the packaging ambient temperature can be monitored and recorded by the RFID tag sensors even when the packagings were away and outside the range of the RFID reader. Extending the intervals between the periodic leakage rate testing of the packagings enhances safety by reducing handling and radiation exposure to workers and cuts annual operating costs during the storage phase of such packagings by US

Training in the Application of the ASME Code to Transportation Packaging of Radioactive Materials

2500–3000 per package.

Training in Quality Assurance for Radioactive Material Transportation Packaging

The Department of Energy has established guidelines for the qualifications and training of technical experts preparing and reviewing the safety analysis report for packaging (SARP) and transportation of radioactive materials. One of the qualifications is a working knowledge of, and familiarity with the ASME Boiler and Pressure Vessel Code, referred to hereafter as the ASME Code. DOE is sponsoring a course on the application of the ASME Code to the transportation packaging of radioactive materials. The course addresses both ASME design requirements and the safety requirements in the federal regulations. The main objective of this paper is to describe the salient features of the course, with the focus on the application of Section III, Divisions 1 and 3, and Section VIII of the ASME Code to the design and construction of the containment vessel and other packaging components used for transportation (and storage) of radioactive materials, including spent nuclear fuel and high-level radioactive waste. The training course includes the ASME Code-related topics that are needed to satisfy all Nuclear Regulatory Commission (NRC) requirements in Title 10 of the Code of Federal Regulation Part 71 (10 CFR 71). Specifically, the topics include requirements for materials, design, fabrication, examination, testing, and quality assurance for containment vessels, bolted closures, components to maintain subcriticality, and other packaging components. The design addresses thermal and pressure loading, fatigue, nonductile fracture and buckling of these components during both normal conditions of transport and hypothetical accident conditions described in 10 CFR 71. Various examples are drawn from the review of certificate applications for Type B and fissile material transportation packagings.Copyright

Thermal analysis of 9977 radioactive material package

The Department of Energy (DOE) has established guidelines for qualifications and training of the technical experts preparing and reviewing the safety analysis reports for packaging (SARP) and transportation of radioactive materials. One of the qualifications is working knowledge of, and familiarity with the quality assurance (QA) requirements in Subpart H of Title 10 of the Code of Federal Regulations Part 71. DOE is sponsoring a course on quality assurance for radioactive material transportation packaging. The objective of this paper is to describe the salient features of the course, the purpose of which is to provide QA training and practical experience that are required to develop and implement a QA plan or prepare the QA chapter of a SARP for the design, fabrication, assembly, testing, maintenance, repair, modification, and use of the packaging. The applicable QA requirements from DOE orders, federal regulations, and NRC regulatory guides will be highlighted, along with a graded approach to selected QA elements from Subpart H of 10 CFR Part 71. The paper will also briefly discuss ASME NQA-1 for Type B and fissile material packaging, current issues resulting from the different emphasis between a compliance-based QA program (in Subpart H, 10 CFR 71) for packaging and a performance-based QA program for DOE nuclear facilities (based on 10 CFR 830, “Nuclear Safety Management”), and the final rule changes in 10 CFR 71 that became effective on October 1, 2004.Copyright

Graded approach to establish QA requirements for type B and fissile material transportation packagings

Abstract The 9977 package is a certified type B transportation packaging that was designed to transport radioactive materials with a decay heat load of up to 19 W. The packaging was recently modified to accommodate increased content heat load (up to 38 W) by employing an aluminium heat dissipating sleeve outside the containment vessel (CV), as well as an aluminium spacer inside the CV holding two 3013 containers. This paper provides highlights of thermal analyses of the modified 9977 package that were performed to evaluate its compliance with the 10 CFR 71 regulatory safety requirements. Parametric studies were also performed to examine effects of (i) surface properties, e.g. light absorptivity and emissivity, of the packaging; (ii) total decay heat loads, ranging from 18 to 38 W; and (iii) distribution of decay heat load inside the CV on the temperature of the Viton O-ring seal. The results of thermal analyses show that for the normal condition of transport with insolation, increasing absorptivity and decreasing emissivity increase the temperature of the O-ring; decreasing heat load decreases the temperature of the O-ring, whereas changing heat load distribution has little effect on the temperature of the O-ring. Likewise, changing the thermal conductivity of the spacer inside the CVhas little effect on the temperature of the O-ring. Briefly discussed is the possible extension of the annual maintenance interval of the 9977 package, based on previous work and the data obtained in the long-term leak performance tests conducted by the Savannah River National Laboratory.

Development of training course on transport security of radioactive materials

Abstract The essence of the graded approach is the establishment of applicable quality assurance (QA) requirements to an extent consistent with the importance to safety of an item, component, system or activity. The genesis of the graded approach is a study conducted by the US Nuclear Regulatory Commission (NRC) for the US Congress in 1987 to assess the effectiveness of QA activities. That study demonstrated the need to improve the application of QA requirements for the nuclear industry in general. The conclusion of the study indicated that a graded approach for establishing QA requirements is the most viable method to satisfy federal safety standards that result in protecting public health and safety. The application of QA requirements for type B and fissile material transportation packagings is not based solely on importance to safety or safety related considerations. The operability of items, components, systems and activities is considered to be equally important. The nuclear industry, along with regulatory agencies, recognises the significance of operability considerations, as well as the evaluation of each item, component, system or activity for safety related considerations. The graded approach for QA requirements for type B and fissile material transportation packagings is based on Title 10, Part 71 of the US Code of Federal Regulations (CFR), ‘Packaging and transportation of radioactive material.’ Guidance for implementation of the QA requirements specified in §71 is provided in NRC Regulatory Guide 7·10, ‘Establishing quality assurance programmes for packaging used in transport of radioactive material,’ and ASME NQA-1, ‘Quality assurance requirements for nuclear facility applications’. The graded approach for QA requirements is based on criteria for containment, shielding and subcriticality specified in 10 CFR Part 71.