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[en] The 11th International Conference on CANDU Maintenance and Nuclear Components was held on October 1-4, 2017 in Toronto, Ontario, Canada. The conference is one of the premier technical conferences held by the Canadian Nuclear Society (CNS) which focusses on the operating nuclear power plants, Ontario's major source of reliable, economic GHG-free electricity, and because of the major refurbishment projects underway to ensure the long-term supply of clean electricity. The three-day program, built around a theme of 'Delivering Clean Energy through CANDU Maintenance and Life Extension', comprised of six plenary sessions, six parallel technical programs, and also a student program that included a poster session based on technical paper submissions.
[en] The International Generic Ageing Lessons Learned (IGALL) programme was developed by the International Atomic Energy Agency to assist Member States in ensuring that aging of structures, systems and components (SSCs) of nuclear power plants (NPPs) is well managed, so that safety levels are maintained during long-term operation. Canadian Nuclear Safety Commission (CNSC) staff have been strong supporters of the IGALL programme since its inception, and lead Canadian participation to ensure that it addresses current, proven best practices and knowledge on aging management for Canadian CANDU® NPPs. Participation in IGALL also helps to ensure that Canadian utilities will benefit from international experience, proven practices, knowledge and lessons learned from Member States with similar CANDU / pressurized heavy-water reactor (PHWR) or light-water reactor technologies. The purpose of this paper is to provide an overview of the IGALL programme and to illustrate how it is applied to managing aging of mechanical, electrical and instrumentation and control (EI&C) components, and civil structures of CANDU NPPs. The aging management programs, time-limited aging analyses and aging management review tables for mechanical, EI&C and structural SSCs of CANDU NPPs are described. The application of the IGALL programme for implementation and compliance with CNSC REGDOC-2.6.3, Aging Management, and REGDOC-2.3.3, Periodic Safety Reviews, is also discussed. Finally, the paper outlines a few suggested areas for further enhancement of the IGALL programme. (author)
[en] This paper discusses the maintenance of nuclear facilities at Pickering and Darlington sites. The maintenance program must prevent failure of critical components to ensure safety and reliability of the plants. Plant must be kept in pristine condition with minimal backlog of corrective maintenance All maintenance must be performed with precision to ensure safety and reliability. All disciplines within the plant have an important role in supporting the front line maintenance worker. Maintenance costs comprise the largest portion of the operating costs of Nuclear plants. New innovative strategies for plant maintenance must be developed. Enhanced availability of digital information for the front line maintenance worker. Replacement of plant equipment with smart devices.
[en] Wireless technologies have been used in nuclear power plants for many years. Various systems utilize wireless technologies to perform their intended function. Some examples that have been employed include wireless security and Emergency Preparedness (EP) radios, Digital Enhanced Cordless Telecommunications (DECT) phone systems, wireless controllers for overhead cranes, and wireless business network Wi-Fi. With the exception of the security and EP radios which tend to operate in the 800-900MHz range, most devices operate well above 1GHz. Because of the overall growth of wireless technology and devices, the increasing costs of employing traditional technologies, and the cost savings efforts that are being embraced by the nuclear industry worldwide, new wireless alternatives should be considered for cost reduction and advanced capability. There are many advantages to deploying a sub-GHz sensor network within an industrial environment. Because sub-GHz frequencies can penetrate massive structures with less attenuation than higher GHz frequencies, it makes them an ideal candidate to employ plant-wide with less overall infrastructure to maintain. The type of networks employed for sub-GHz devices typically provides better signal strength and signal to noise ratios in areas of the plant where it is difficult to access or install permanent communications equipment. Some challenges exist with integrating new technology such as LTE-M and LoRa protocol based sensors into existing infrastructure, such as a Distributed Antenna System . Other challenges exist with battery consumption for wireless sensors versus data pull rates and data rate limitations. There are many applications for sub-GHz wireless technology to include supplemental monitoring (I&C) of plant processes, security monitoring, remote tamper indication, operations monitoring (i.e. manual valve position indication), unmanned fire watch, etc. Many of the applications are intended to provide additional monitoring capability, provided capability for predictive maintenance, or reduce the overall time and expense of Operations and Maintenance of the plant.
[en] Ultrasonic techniques are widely used for a variety of diagnostic and monitoring purposes. The ability to transmit and receive signals through pressure boundaries, and their proven accuracy in measuring flow have made them essential to the nuclear industry, particularly for flaw detection and flow measurements. We review the current use of ultrasonic technology in applications to nuclear power plants and report on recent advances in ultrasonic flow-measurement technology, including adaptations of cross correlation techniques and tests of specialized transducers. We suggest a number of potential but clearly achievable improvements in ultrasonic technology that could improve its usefulness to nuclear operators.
[en] Fretting-wear damage between a vibrating structure and its supports is discussed in this paper. Typical components of concern are piping systems and pipe-supports, heat exchanger tubes and tube supports, and nuclear fuel bundles and fuel channels. Fretting-wear damage is related to the dynamic interaction between a structure and its supports. This interaction is conveniently formulated in terms of a parameter called 'work-rate' to predict fretting-wear damage. Work-rate is simply the integral of contact force over sliding distance per unit time. Fretting-wear damage may be investigated from an energy point of view. It is essentially the mechanical energy or power dissipated through contact forces and sliding that causes fretting-wear damage. Development of a simple formulation that relates tube vibration response and fretting-wear damage is presented in this paper. Several practical examples and simple calculations are discussed.
[en] It just so happens that achieving world-class performance in a nuclear facility also reduces the risks that are of concern to insurers who underwrite nuclear liability and nuclear peril. Our objectives being the same, insurance inspections of the past have now become 'surveys' that are far more collaborative in nature. These surveys are performed by engineers and specialists with significant experience in the Canadian nuclear industry. Survey outcomes play a major role in determining insurability and establishing premiums. The Nuclear Insurance Association of Canada (NIAC), the Canadian nuclear insurance pool, boasts a team of three surveyors with more than 120 years of nuclear power plant experience. Their surveys touch on all aspects of a nuclear facility's operation as defined by international guidelines that have been written by surveyors from insurance pools around the world including Canada, and incorporate industry best practices. Nuclear liability insurance is concerned with the risk to the public from reactor operation, while nuclear peril insurance is concerned with casualties and equipment damage from radioactivity arising from a facility's operation. The survey guidelines are therefore aligned to best address these risks: Nuclear Safety, Operations and Third-Party Liability (NSO-TPL); Fire Safety (FP), in support of NSO-TPL; Machinery Breakdown Prevention (MB), in support of NSO-TPL); and Nuclear Safety Culture, in support of all of the above. Fire and Machinery Breakdown have been the focus of the conventional insurance industry for well over a century. In the nuclear context, they continue to be significant contributors to a much broader scope that includes such themes as organizational effectiveness, training, emergency preparedness, radiation protection, to name but a few. This presentation will walk you through a typical survey cycle, focusing on survey methodology and the interface with the facility operator.
[en] Ion exchange resins are an accepted and established water treatment method for condensate polishing for the removal of species prone to cause corrosion. The minimization of such species lead to the minimization of asset degradation from corrosion and thereby leads to potentially decreased maintenance and increased asset longevity. The purity of the ion exchange resin itself has an impact on this goal. The presence of chloride is detrimental in high-purity water systems and the ion-exchange resin can be a source of the chloride ion. Chloride ions in high pressure steam cycle chemistry (PWRs) can be concentrated by a factor of 100-350X leading to increased conductivity and promotion of corrosive reactions. Thus, dependent upon the chloride maximum specification, even ion exchange resins can contribute to the chloride level in the condensate. Historically, 40 years ago, chloride specification for ion exchange resins were as high as 5%. Currently, it is at 0.5% for typical condensate and 0.1% for nuclear grade. The Ultra-Low Chloride (ULC) Anion Ion Exchange Resin has a specification of 0.05% with actual values typically well below this specification. The Ultra-Low Chloride (ULC) Anion Ion Exchange Resin is manufactured by Graver Technologies via a specific anion regeneration process which enables the new low chloride benchmark specification to be established. This new industry benchmark has been well-vetted for station improvements per multiple- year utilization of Gravex GR 1-9 US Ultra (uniform particle size) and Gravex GR-1-9 NG ULC (Gaussian particle size distribution) at both PWR and BWR stations, respectively, in the northeast and mid-Atlantic regions of the United States.
[en] This paper discusses the use of complimentary workforce. Supplemental workforce do not always feel part of our team. This leads to poor teamwork, misaligned standards resulting in rework. This leads to a lack of trust. Currently, supplemental workforce on board independently and not given the same introduction to standards and expectations. Contract staff are referred to as supplemental staff or transient workers. In future, training for supplemental supervisors is joint with onsite and complimentary workers together and delivered consistent with on site standards and expectations.
[en] In 2016, the Pickering Nuclear Generating Station enjoyed one of the best years in the stations history. This strong performance has continued in 2017 and is characterized by historically low Forced Loss Rate, well managed outages, and record setting periods of continuous operation on several of the Pickering units. This performance stands in sharp contrast to that of the preceding ten years or so. This presentation will describe the contributors and causes of past performance shortfalls and how Ontario Power Generation has driven improvements in human and equipment performance during this period.