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Nuclear reactor inspections are critical to ensure the safety and reliability of a nuclear facility’s operation. In Canada, ultrasonic testing (UT) is used to inspect the health of pressure tubes that are part of Canada’s Deuterium Uranium (CANDU) reactor’s fuel channels. Currently, analysis of UT scans is performed by manual visualization and measurement to locate, characterize, and disposition flaws. Therefore, there is motivation to develop an automated method that is fast and accurate. In this article, a proof of concept (PoC) that automates the detection of flaws in nuclear fuel channel UT scans using a convolutional neural network (CNN) is presented. The CNN model was trained after constructing a dataset using historical UT scans and the corresponding inspection results. The requirement for this prototype was to identify the location of at least a portion of each flaw in UT scans while minimizing false positives (FPs). The proposed CNN model achieves this target by automatically identifying at least a portion of each flaw where further manual analysis is performed to identify the width, the length, and the type of the flaw. [ABSTRACT FROM AUTHOR]

Britain and Canada, two major nuclear Cold War actors, refrained from establishing close nuclear ties with Israel from 1958 to 1974, despite Israel's consistent interest in importing civilian nuclear technology. This was true both before and after the nuclear Non-Proliferation Treaty came into force in 1970, even though the treaty allowed for the export of safeguarded nuclear reactors. In comparison, the other two leading nuclear exporters of the period, France and the United States, were much more involved in the initial stages of the Israeli nuclear programme, exporting research reactors to Israel in the 1950s. How did Britain and Canada view Israel's military and civilian nuclear programme from 1958 to 1974? How did they form their nuclear export policy towards Israel and what considerations motivated them? This analysis examines these questions using archival material from British and Canadian archives. [ABSTRACT FROM AUTHOR]

Although some countries plan to build new nuclear power plants in the near future, in aggregate the data indicates that nuclear power's influence will continue to dwindle across the globe in coming decades. [ABSTRACT FROM AUTHOR]

• Implementation of a novel CFD-based model for reactor transient simulation. • Simulation of an unprotected loss of flow (ULOF) transient in a small lead cooled reactor (SEALER) • Comparison with a lumped-parameter model. • Study on the effect of the pump flywheel size. The recent development of small modular reactors needs to be followed by safety analysis using the newest available tools. This work focuses on one type of reactor, SEALER, which is a small lead cooled reactor intended for remote communities in Canada. Simulations of a loss of flow transients are performed using a CFD-based model that was specifically developed for this project. The CFD geometry includes the entire primary circuit with some simplifications. The fuel channel, steam generator and pumps use a simple geometry with momentum source and heat source/sink. Free surface level is modelled with the multiphase volume of fluid (VOF) method. The CFD part of the model is coupled to a custom code for heat transfer in the fuel rods and point kinetics for neutronics. Transient results show that core temperatures do not increase significantly and stay well below coolant boiling and fuel melting points. The CFD-based model presented here is compared against a lumped-parameter model using the same transient. It is shown that the evolution of the mass flow and temperature is significantly different and more detailed with the CFD-based model. Finally, the influence of the moment of inertia of the pump flywheel on the transient is explored. [ABSTRACT FROM AUTHOR]

A significant transition in Canada's electricity system is needed to achieve the zero-emission target that has been set for 2035. Many studies have charted possible decarbonization pathways to achieve this target, but most focus on commercially available generation technologies. In this study, we modify and deploy the electricity system planning model, COPPER, to explore the role of emerging technologies in Canada's electricity system transition under a suite of plausible scenarios. Results show that, if developed and deployed, low- or non-emitting thermal technologies alongside offshore wind could contribute to the transition on the national scale, but specific adoption patterns differ by province: provinces that must phase out fossil fuel generation add natural gas with carbon capture and storage to provide dispatchable capacity with low operation cost; provinces with an emissions cap or inflexible network integrate hydrogen combustion that operates as peaking facilities; offshore wind and small modular reactors are part of the optimal mix for emissions constrained provinces or provinces with a flexible network, respectively. Since the best-suited technologies differ by region, provinces should explore available opportunities, including emerging technology, identify suitable options, and leverage them to facilitate their electricity system transitions. • Dispatchable non- or low-emitting technologies can play a major role in the future. • Gas with carbon capture and storage can be used to meet the baseload demand. • Hydrogen has the potential to substitude natural gas. • Offshore wind is expected to contribute to the transition modestly. • Further reductions in small modular nuclear reactors costs are required to become cost-effective. [ABSTRACT FROM AUTHOR]

Removal half-life (RHL) of tritium is one of the best means for optimising medical treatment, reduction of committed effective dose (CED) and quick/easy handling of a large group of workers for medical treatment reference. The removal of tritium from the body depends on age, temperature, relative humidity and daily rainfall; so tritium removal rate, its follow-up and proper data analysis and recording are the best techniques for management of accidental acute tritium exposed cases. The decision of referring for medical treatment or medical intervention (MI) would be based on workers' tritium RHL history taken from their bodies at the facilities. The workers with tritium intake up to 1 ALI shall not be considered for medical treatment as it is a derived limit of annual total effective dose. The short-term MI may be considered for tritium intake of 1–10 ALI; however, if the results show intake ≥100 ALI, extended strong medical/therapeutic intervention may be recommended based on the severity of exposure for maximum CED reduction requirements and annual total effective dose limit. The methodology is very useful for pressurized heavy water reactors (PHWRs) which are mainly operated by Canada and India and future fusion reactor technologies. Proper management will optimise the cases for medical treatment and enhance public acceptance of nuclear fission and fusion reactor technologies. [ABSTRACT FROM AUTHOR]

Atomic energy developed from 1940 as a subject shrouded in secrecy. Identified successively as a crucial element in military strategy, national status and export aspirations, the research and development of atomic piles (nuclear chain-reactors) were nurtured at isolated installations. Like monastic orders, new national laboratories managed their specialist workers in occupational environments that were simultaneously cosseted and constrained, defining regional variants of a new state-managed discipline: reactor technology. This paper discusses the significance of security in defining the new subject in the USA, UK and Canada - wartime allies with similar political traditions distinct but trajectories in this field during the Cold War. The intellectual borders and content of the subject developed differently in each country, shaped under the umbrella of secrecy by disparate clusters of expertise, industrial traditions, and national goals. The nascent cadre was contained until the mid 1950s by classified publications and state-sponsored specialist courses. The early context of high security filtered its members and capped enduringly both their professional aspirations and public engagement. [ABSTRACT FROM AUTHOR]

Abstract: Allowance for the continued operation of feeder piping at some Canadian CANDU stations, which is experiencing active degradation mechanisms, has been based primarily on augmented inspection practices and conservative fitness for service assessments. The major degradation mechanisms identified to date are: pipe wall thinning due to Flow Accelerated Corrosion (FAC) and service induced cracking due to Intergranular Cracking due to Stress Corrosion Cracking (SCC) and potentially Low Temperature Creep Cracking (LTCC) mechanisms. Given that currently available industry codes and standards do not provide sufficient guidelines/criteria for assessing the degradation of feeder pipes, the Canadian Nuclear Safety Commission (CNSC) has asked the utilities to establish feeder pipe specific procedures to provide reasonable assurance that the risk associated with the feeder degradation is maintained at an acceptably low level. In response to this requirement, the Canadian CANDU industry has developed and continued to update feeder fitness for service guidelines to provide evaluation procedures and industry standard acceptance criteria for assessing the structural integrity of the feeder pipes. The scope and frequency of inspections are determined based on the results of the fitness for service assessments taking into account the relative susceptibility of feeder pipes to each specific degradation mechanism. While industry practices for the management of degraded feeder pipes have, in general, been complied with the regulatory expectations, outstanding issues still remain. Major regulatory concerns include uncertainties associated with limitations in both the inspection techniques and the mechanistic understanding of the degradation processes, which can impede inspection planning and fitness for service assessments. This paper presents the regulator''s view of the current situation with respect to degradation of feeder piping, its implications for nuclear safety and the regulatory expectations on industry''s management of the critical ageing phenomena. [Copyright &y& Elsevier]

The article examines the measures undertaken by the government of Canada during the international shortage of medical isotopes, after it discovered the shutdown of the reactor in Chalk River, Ontario that included the termination of Linda Keen as chief executive officer and president of the Canadian Nuclear Safety Commission. The forced resignation of Keen provoked an international debate on the interference of the government in an independent agency. However, the Federal Court sided with the government as it dismissed the appeal made by Keen.

Abstract: This paper presents recent Canadian advances in nuclear-based production of hydrogen by electrolysis and the thermochemical copper–chlorine (Cu–Cl) cycle. This includes individual process and reactor developments within the Cu–Cl cycle, thermochemical properties, advanced materials, controls, safety, reliability, economic analysis of electrolysis at off-peak hours, and integrating hydrogen plants with Canada''s nuclear power plants. These enabling technologies are being developed by a Canadian consortium, as part of the Generation IV International Forum (GIF) for hydrogen production from the next generation of nuclear reactors. [Copyright &y& Elsevier]

It is regarded that the spent resins from the water purification systems of moderator (MOD) and the primary coolant of the Canada deuterium uranium-pressurized heavy water reactor (CANDU-PHWR) are a unique waste, owing to their high 14C and gamma-emitting nuclides. In this work, 14C and 3H contents, anion and cation fractions and the predominant gamma-emitting nuclides of the spent resins from 4 units of CANDUPHWRs, were investigated. Also the chemical species of 14C of the spent resins were determined. For a simultaneous separation of 14C and 3H from the spent resins, the wet oxidation-16 wt% H2SO4 stripping process was utilized. The 14C and 3H activity concentration range of the spent resins of the nuclear power plant (NPP), 4 units of all CANDU-PHWR types, was 2.48E5 Bq/g ∼5.33E6 Bq/g, 1.29E5 Bq/g and ∼2.33E5 Bq/g, respectively. Among the analyzed spent resins, the highest 14C and 3H activity concentration was detected in units 4 and 3, respectively. It was found that more than 92% of the 14C activity concentration was retained on the anion resin and the predominant chemical species was inorganic 14C. It was revealed that the anion resin fraction of the spent resins from unit 1 and unit 2, was about 40% and that of unit 3 and unit 4 was around 60%. More than 80% of the total gamma-radioactivity concentration was associated with the cation fraction of the spent resin. The predominant gamma-emitting nuclide of the spent resin for unit 2 was 137Cs, a fission product, and that for unit 4 was 60Co, a corrosion product. [ABSTRACT FROM AUTHOR]

Abstract: This paper discusses the severe accident management guidance (SAMG) development process undertaken for the Canadian CANDU 6 nuclear power plants (NPPs); the customization process of the generic CANDU SAMG for the Point Lepreau NPP is presented. Examples of severe accident management (SAM) guidelines related to containment pressure control are included in this paper. This paper also provides an overview summary of the severe accident analysis program at Atomic Energy of Canada Limited (AECL) that complements the SAM guidelines development process for the CANDU 6 NPPs in Canada. These analyses provided insights into the accident progression and basis to develop the SAM guidelines. [Copyright &y& Elsevier]

A three-dimensional (3-D) computational fluid dynamics (CFD) model has been developed to analyze the liquid poison injection phenomenon of shutdown system 2 (SDS-2) of a Canada deuterium uranium (CANDU) reactor. Because the SDS-2 injects highly pressurized liquid poison into the moderator in a very short time, it is a major safety priority to confirm the effectiveness of the SDS-2 as one of the shutdown systems. In general, it is difficult to directly measure the velocity and concentration of the poison jet during an injection because of the complex nature of the injection system and the process. Therefore, a series of investigations has been performed to develop a CFD model for liquid poison injection phenomenon with limited validations. In this study, the validation of the existing CFD model for the poison injection phenomenon of the CANDU SDS-2 is extended to be applicable to a CANDU-6 reactor as well as a larger CANDU reactor. The analyses showed that the poison jet growth for those experiments simulated by the 3-D CFD model agrees reasonably with the experimental results. Therefore, it is concluded that the proposed 3-D CFD model can be used to assess the effectiveness of a liquid poison injection in compliance with the intended functional design requirements of the CANDU SDS-2. [ABSTRACT FROM AUTHOR]

When reactivity insertion such as refueling occurs in Canada deuterium uranium (CANDU) reactors, the power and the water level are tilted in the upper outer zone of the liquid zone control system (LZCS) and fluctuate unstably for a certain period of time (1 to 5 days). Such instability is observed in most of the CANDU reactors in service around the world, but neither its root cause has been identified nor have solutions against it been established. Therefore, this study experimentally and analytically attempted to prove that the root cause lies in the holdup of light water on the top of the tube support plate (TSP) due to the mismatch between the net volumetric flow rate of light water and helium crossing the narrowed porous TSP installed within the LZCS compartment by performing hydrodynamic simulation of the inflow/outflow of light water and helium. Two solutions against the aforementioned instability of LZCS were suggested. One is to regulate volumes of helium gas flowing into the compartment and light water flowing therefrom, and the other is to enlarge the flowing paths of helium and light water within the TSP. The former may be applicable to nuclear reactors in service and the latter to those planned to be constructed. [ABSTRACT FROM AUTHOR]

Though Canada established formal diplomatic relations with the Republic of Korea in 1964, there was no embassy in Seoul until 1973. That year D. Gordon Longmuir was dispatched to Seoul to help open that embassy and serve as First Secretary and Consul, as well as Chargé d'Affaires until a resident ambassador arrived early in 1974. He stayed in Seoul until 1976. Among the more pressing duties of the embassy while he was stationed there was ensuring adequate safeguards for a nuclear reactor Korea was considering buying from Atomic Energy of Canada Limited (AECL). At first Canada, somewhat distrustful of President Park Chung Hee, was uncertain whether or not to provide Park with such a nuclear power plant. However, after the ROK agreed to ratify the Nuclear Non-proliferation Treaty, the deal was signed and Korea eventually went on to purchase a total of four Canadian-designed CANDU nuclear reactors. As a representative of the Canadian government, Longmuir was in the audience on August 15, 1974, when a disgruntled Korean-Japanese attempted to assassinate Park but shot and killed Park's wife instead. He also watched as, under Park's leadership, the Korean economy began its rapid march to modernization while the government resisted pressure for democratization. The embassy occasionally had to intervene on behalf of some activist Canadian missionaries who felt that urban workers were being asked to pay too heavy a price for Korea's economic progress. [ABSTRACT FROM AUTHOR]

The Alberta oil-sands bitumen deposits comprise one of the largest sources of hydrocarbon in the world, and have emerged as the fastest-growing, soon to be dominant, source of crude oil in Canada. Although the oil industry has made great strides in improving the effectiveness of gathering this resource, the main challenge that remains is the large quantity of energy needed in the process of extracting the oil and upgrading it to commercial levels. However, over the past few years, developments in oil- sands extraction technology, and developments in CANDU technology through the advanced CANDU reactor, (ACR™), have converged so that a practical, economical match of nuclear energy to the oil sands is now available. This paper describes recent studies by Atomic Energy of Canada Limited (AECL) and by the Canadian Energy Research Institute (CERI) to look at the adaptation of the ACR design for use in the oil sands, in particular with regard to economic viability. Issues raised in these studies are discussed, along with priorities for further work. [ABSTRACT FROM AUTHOR]

Discusses life management strategies for fuel channels of the Canada Deuterium Uranium (CANDU) nuclear reactor. Inspection and evaluation program for mechanisms that affect fitness for service; Safety and reliability in operation of current pressure tubes; Dimensional changes; Deuterium ingress; Material properties; In-service damage and wear.

The article explores issues concerning the redesign of the Canada Deuterium Uranium nuclear reactor. The government-owned Atomic Energy of Canada Ltd. (AECL) redesigned the reactor and called it the Advanced CANDU. Unlike previous generations of the reactors which relied on expensive, hard-to-handle heavy water coolant, the new design will be cooled with light water, making it roughly $200 million cheaper to build. The new design aims to overcome the problem of earlier design which is the complex system of hundreds radioactive fuel tubes and coolant pipes running into the reactor core. According to Pat Tighe, vice president for sales at AECL, CANDU are cheaper to operate and maintain than U.S. and pressurize-water reactor from France.

Presents news briefs related to the environment as of November 1977. Decrease in the amount of air pollution in Canada during 1970 through 1974; Possible adoption of a moratorium on construction of nuclear reactors by the West German government; Use of shredding machines to destroy some critical documents at Industrial Bio-Test Laboratories.

The article focuses on the controversy regarding the nuclear reactor in Chalk River in Ontario, Canada, which produces the raw materials for medical isotopes. It notes that the controversy has become an international embarrassment for Canada while some European isotope producers has refused to participate in the efforts to coordinate with the international isotope supply. On the other hand, it also reveals that the conflict between the U.S. and the company MDS Nordion is prompting calls for the creation of a domestic supplier which would get the company of its greatest customer. INSET: Securing Canada's isotope supply.

The article offers world news briefs about nuclear power. The first nuclear reactor, a research plant with a 2,000 kilowatts capacity began its operation in Swierk, Poland on June 14,1958. Twelve West European countries signed a three-year agreement for joint research on the Halden nuclear reactor in Norway on June 1958. The first nuclear power station in Canada resumed its construction, with 20,000 electrical kilowatts capacity and will serve as pilot project for large scale plants.

The article reports on the developments in field of nuclear weapons and atomic research of various countries. National Research Universal, Canada's third atomic research reactor is almost completed at Chalk River, Ontario of which it is considered the most powerful materials testing reactor in the Western world due to its size and high neutron flux. Jawaharlal Nehru of India claimed that architectural plans are made and approved for the Atomic Energy Establishment and the swimming pool reactor which was designed and built by personnel of the establishment has been critical. Norway's 20,000-kilowatt boiling water reactor is estimated to cost $700,000 to construct.

The article reports global events related to nuclear research and development. The Atomic Energy Commission of Australia announced the site for its research laboratories and nuclear reactor. It is hoped the major part of the laboratories will be completed by the end of 1956. After a decade of nuclear research and development, Canada has resumed its operation of the Chalk River reactor, NRX, and a larger reactor is under construction. Moscow has announced the construction of a second nuclear power reactor, with a capacity of 100,000 kilowatts.

The article reports on the announcement given by the Canadian Trade Minister C. D. Howe regarding the plan to build an atomic pile at Chalk River in Ontario, Canada. The approval for the proposal is certain, although it was not yet submitted to the Parliament. The new pile is going to be commercial research project, and the sale of plutonium and isotopes is expected to put Chalk River on a paying basis. Howe suggests that the new development enables Canada to discuss the problems in atomic development specifically with the breeding of fissionable material and the design of atomic power plants.