Longevity of sensors and portable devices are severely limited by temperature, chemical instability, and electrolyte leakage issues associated with conventional electrochemical batteries. Batteries undergo self-discharge and permanent loss of capacity at high temperatures, exhibit lower voltage and capacity at low temperatures, and leak electrolyte shortening operating lives, corrosion of nearby electronics, and potential safety hazards in the form of burns and poisoning. Instabilities in lithium types often short resulting explosions, fire, and venting of hazardous gasses. Betavoltaics do not have these problems and can operate in a wide temperature range without permanent degradation and loss of capacity, will not explode, and be made safe. Betavoltaic technology is maturing with advances in radioisotope sources, semiconductor materials, and developments in low-power applications, and has been identified by Department of Defense as a disruptive technology that is needed and should be pursued. This study presents experimental and modeling research on the leading betavoltaic technology, recent developments and proposed advancements. The next generation 100 microwatt betavoltaic is introduced along with projected voltage, current, and power characteristics.

In the work, we employed a new method to monitor the behavior of the grounded control rod. To this end, a sensor system based on the two-electrode capacitance is applied to measure the rod position in nuclear heating reactor. Additionally, the finite element method was used to analyze the capacitance of the sensors composed of two-electrode. According to the different electric properties of grounded control rod and air, this apparatus determines the control rod position using an interface electronics method and two -electrode capacitance sensor. The capacitance data obtained by simulations were compared with experiment results to verify the measurement accuracy. The subsequent quantitative analyses on the data indicate the reliability and accuracy of the apparatus for monitoring rod position. It is demonstrated that such a system shows very promising applications for measurements of the control rod position of nuclear reactor.

Impinging jet cooling technique has been widely used extensively in various industrial processes, namely, cooling and drying of films and papers, processing of metals and glasses, cooling of gas turbine blades and most recently cooling of various components of electronic devices. Due to high heat removal rate the jet impingement cooling of the hot surfaces is being used in nuclear industries. During the loss of coolant accidents (LOCA) in nuclear power plant, an emergency core cooling system (ECCS) cool the cluster of clad tubes using consisting of fuel rods. Controlled cooling, as an important procedure of thermal-mechanical control processing technology, is helpful to improve the microstructure and mechanical properties of steel. In industries for heat transfer efficiency and homogeneous cooling performance which usually requires a jet impingement with improved heat transfer capacity and controllability. It provides better cooling in comparison to air. Rapid quenching by water jet, sometimes, may lead to formation of cracks and poor ductility to the quenched surface. Spray and mist jet impingement offers an alternative method to uncontrolled rapid cooling, particularly in steel and electronics industries. Mist jet impingement cooling of downward facing hot surface has not been extensively studied in the literature. The present experimental study analyzes the heat transfer characteristics a 0.15mm thick hot horizontal stainless steel (SS-304) foil using Internal mixing full cone (spray angle 20 deg) mist nozzle from the bottom side. Experiments have been performed for the varied range of water pressure (0.7–4.0 bar) and air pressure (0.4–5.8 bar). The effect of water and air inlet pressures, on the surface heat flux has been examined in this study. The maximum surface heat flux is achieved at stagnation point and is not affected by the change in nozzle to plate distance, Air and Water flow rates.

In this paper we present the results of the CSNI task group on the Robustness of Electrical systems in the light of the Fukushima Daiichi accident (ROBELSYS). Based on the conclusion of a workshop organized in April 2014 and on further work, this task group has identified the three following main areas for international cooperation: Enhancement of the robustness of electrical systems, development and improvement in the analysis and simulation of the behavior of NPP’s electrical systems and safety challenges related to the use of power and software based electronics in electrical power systems. The paper concludes on the recently approved CSNI framework that will address these issues.

In this paper, we study the electronics in the instrumentation and control (I&C) systems for an accelerator driven sub-critical (ADS) system, where a target located at the centre of a sub-critical reactor core is bombarded by the protons from an accelerator. In comparison with a commercial reactor used in nuclear industry, more control electronics are required to exactly couple the high-energy beam from the accelerator to the spallation target in the reactor core. There is a strong drive to utilize standard commercial-off-the-shelf devices to minimize cost and development time. In order to improve the reliability of I&C systems, redundancy architecture has been considered by adding more electronic devices. In comparison with I&C system without redundancy, the dual redundancy architecture improves the reliability of the system by 20000 times. Then, we study the potential application of electronics devices, such as the preamplifiers for detectors, in the reactor building by shielding them with shielding materials. Since the most effective neutrons in creating radiation damages are those fast neutrons with the energy of more than 0.1 MeV, we have proposed a sandwich shielding method to reduce the neutron-induced radiation effects, in which the first and third layers are made of polyethylene and the second layer is made of heavy metal, e.g. tungsten. Simulation results with GEANT4 code have indicated that the shielding with a 30 cm-thick sandwich can increase the expected lifetime of electronics by 1258 times, and can reduce the soft errors caused by single event upsets by 5400 times.

High power electronics are widely used in many different areas such as integrated circuit (IC) boards in nuclear reactor control system. Thermal management of electronic devices has been a topic of great interest among many researchers over the last few decades. Microchannel is one of several high-heat-flux removal techniques. Nanofluids with enhanced thermal conductivity and strong temperature- and size-dependent thermal properties are expected to be utilized in microchannels as coolants, which leads to a promising future for such high-heat-flux systems as cooling systems. The performance of the microchannel heat sink (MCHS) using water and Al 2 O 3 /water nanofluids, with consideration of different substrate materials, is numerically investigated and compared in the present paper to identify the combined effects of working fluids and substrate materials on the thermal resistance, pumping power and temperature distribution on the substrate surface of a heat sink.

Micro arc oxidation (MAO) technology known as a newly surface treatment technology has got a widely application in the field of aviation, aerospace, automotive, electronics, and medical industry. Strength, toughness, hardness and corrosion of valve metal such as aluminum, magnesium, copper, zinc, zirconium and their alloys can be greatly improved by MAO technology. This paper tries to probe into the feasibility of using MAO technology in nuclear power industry. Aluminum and its alloys are used as structural materials such as the cladding of reactor fuel and all kinds of pipes in the low nuclear reactor. Zirconium alloys are widely used for the fuel cladding, cannula, catheter and other components of the fuel assemblies. Titanium and its alloys offer a unique combination of desirable mechanical properties which makes them to be the candidate materials for structural application in the field of nuclear energy. The surface of all these materials may be destroyed which increasing the risk of the nuclear accident due to the severe serving conditions. As a result, it is necessary to improve the corrosion and wear resistance behavior. With the urgent requirements of safety and durability of nuclear reactor, MAO technology must have a broad prospect in nuclear industry.

Energy utilization from low-grade fuels of either fossil or renewable origin, or from medium-temperature heat sources such as solar, industrial waste heat, or small nuclear reactors, for small-scale power generation via steam cycles, can be reasonably enhanced by a simple technology shift. This study evaluates the technical feasibility of a compact power generation package comprising a steam turbine directly coupled to a high-speed alternator delivering around 8–12 MW of electrical power. Commercial or research-phase high-speed electrical generators at MW-scale are reviewed, and a basic thermodynamic design and flow-path analysis of a steam turbine able to drive such a generator is attempted. High-speed direct drives are winning new grounds due to their abilities to be speed-controlled and to avoid the gearbox otherwise typical for small system drivetrains. These two features may offer a reasonable advantage to conventional drives in terms of higher reliability and better economy. High-speed alternators with related power electronics are nowadays becoming increasingly available for the MW-size market. A generic 8 to 12 MW synchronous alternator running respectively at 15,000 to 10,000 rpm, have been used as a reference for evaluating the fundamental design of a directly coupled steam turbine prime mover. The moderate steam parameter concept suits well for converting mid-temperature thermal energy into electrical power with the help of low-tech steam cycles, allowing for distributed electricity production at reasonable costs and efficiency. Steam superheat temperatures below 350°C (660°F) at pressures of maximum 20 bar would keep the steam volumetric flow sufficiently high in order to restrain the turbine losses typical for small-scale turbines, while helping also with simpler certification and safety procedures and using primarily established technology and standard components. The proposed steam turbines designs and their characteristics thereof have been evaluated by computer simulations using the in-house code ProSteam and its sub-procedures AXIAL and VaxCalc, by courtesy of Siemens Industrial Turbomachinery and its steam turbine division located in Finspong, Sweden. The first results from this study show that high-speed steam turbines of the proposed size and type are possible to design and manufacture based on conventional components, and can be expected to deliver a very satisfactory performance at variable power output.

A gamma spectrometer based on LaBr 3 (Ce) crystal has been developed. The spectrometer uses a compact data acquisition system including a multi-channel analyzer and corresponding electronics components. The response function of the detector has been simulated using Monte Carlo Code (MCNPX 2.7E). It has been also tested, at the University of Ontario Institute of Technology radiation facilities, using a series of gamma radiation sources. The simulated data has been compared with experiments and a good agreement has been achieved. This paper presents the parameters of the developed spectrometer and the results of its testing along with a comparison with NaI(TI) crystal.

The purpose of this paper is to highlight recent US nuclear power industry operating experience using high frequency acoustic emission (AE) valve leak detection technology to: ▸ Troubleshoot LLRT boundaries ▸ Identify internal through valve leakage ▸ Limit personnel exposure ▸ Limit outage schedule slippage ▸ Optimize & prioritize work scopes ▸ Eliminate unnecessary work orders ▸ Supplement existing troubleshooting methods ▸ Limit maintenance induced failures Several examples where AE technology has been successfully utilized to make intelligent decisions related to the maintenance and testing of valves in nuclear power plants are examined including the resulting savings in time, personnel exposure and cost. The specific examples discussed herein represent the experiences of different plants, reactor types, systems and process mediums. While utilizing acoustic or ultrasonic equipment as a troubleshooting tool for valves may not be considered groundbreaking, the acoustic emission system discussed in this paper was specifically designed for the early detection of leakage through a closed valve (sometimes known as “passing”). Because of the unique design of the AE sensor and associated electronics this new approach is essentially deaf to and thus unable to “hear” much of the background noise that has historically complicated use of existing general purpose acoustic or ultrasonic tools to reliably detect through valve leakage. As a consequence, it is now much easier for a novice technician to identify a leaking valve in a noisy operating plant environment. This new equipment was developed by a large UK based company as a result of experience with major oil and gas customers around the world where detection of through valve leakage in systems that contain explosive hydrocarbon products is a critical safety issue. This new technology has recently found a home in US nuclear power plants where it has been proven to quickly identify the location of leak paths during Appendix J leak rate testing, as a troubleshooting tool to identify or confirm suspected leaking valves and on the secondary side to identify costly steam losses.

BELGONUCLEAIRE has been operating the Dessel plant from the mid-80’s at industrial scale. In this period, over 35 metric tons of plutonium (HM) has been processed into almost 100 reloads of MOX fuel for commercial west-european light water reactors. In late 2005, the decision was made to stop the production because of the shortage of the MOX fuel market remaining accessible to BELGONUCLEAIRE. As a significant part of the decommissioning project of this Dessel plant, about 170 medium-sized glove boxes and about 1.300 metric tons of structure and equipment outside the glove boxes are planned for dismantling. The dismantling works are expected to start in the second quarter of 2009. On account of stringent internal rules of alpha-containment during over 25 years of operation, there is no significant contamination of the plant, outside the glove boxes; that assumption has been confirmed by radiological surveys performed by independent bodies in 2001 and 2008. Therefore most of the materials outside the glove boxes that were not a priori destined for radioactive waste will be released without restriction on the basis of the applicable legal regulations in Belgium (ARBIS), along with the buildings and the plant site. In this paper, after having reviewed the different regulations in Belgium, the authors introduce the different options considered for release of materials, and the main decision criteria (process, safety aspects, radiological, etc) for the different expected types of materials (inert materials, metals, plastics, electrical cabinets and cables and electronics) are analysed. Besides the regulatory aspects, the technological and economical aspects are considered (as an example, comprehensive metal smelting is implemented, as a favourite solution because it provides with decontamination, homogeneization and volume characterization).

A computational fluid dynamics (CFD) model has been developed to predict air temperatures within the switchgear room environment of a nuclear plant’s Electronics Auxiliary Building (EAB). In order to validate the CFD model output, a scale model experiment has been developed using an analytical model to properly scale important EAB room parameters to allow small scale experiments to be performed for validation of the CFD model. The focus of this paper is the development of the methodology used to accurately predict the bulk air temperature or the EAB room. The CFD model is compared to a simple lumped parameter model as well as a scale model experiment. The scaling approach matches the eigenvalues of the lumped parameter model. An experiment based on this scaling approach was performed and compared with CFD output. The time predicted by the CFD model of the Electrical Auxiliary Building room for the average air temperature to increase from 17.7 °C (64 °F) to 40 °C (104 °F) is 23.5 minutes. The lumped parameter analytic solution produces a mean time of 22 minutes. The heat up time for the experiment matches the CFD model providing confidence in the fidelity of the CFD model.

A new generation of Alkaline earth sulfides (MgS, CaS, and BaS) doped with rare-earth ions have been identified by the University of Montpellier as the very high sensitivity of these phosphors, the short time constant of the luminescence and the perfectly separated spectra enable many applications in real time and online dosimetry. The online detecting technology of optically stimulated luminescent (OSL) radiation dosimeter main make use of the OSL characteristics of doping the alkaline-earth metal sulphides, makes the material into the thin films for storing energy from Ionizing radiation, the excitation light through optical fibers reached the where under radiation-field, with a sensitive detection device to read out the radiation dose from storing the OSL material, obtains a novel technology of radiation dose measurement. In the previous works, the dosimeter benefits from a printed circuit board mount. Both the sensor and the electronics are exposed to radiation, the problem of the radiation induced damage is supposedly being addressed. In both cases, the use of optical fibers can provide an elegant solution. Optical fibers offer a unique capability for remote monitoring of radiation in difficult-to-access and hazardous locations. Optical fiber can be located in radiation hazardous areas and optically interrogated from a safe distance. Hence, optical fiber dosemeters are immune to electrical and radio-frequency interference that can seriously degrade the performance of remote electronic dosimeters. In this paper, a novel remote optical fiber radiation dosimeter is described. The optical fiber dosimeter takes advantage of the charge trapping materials CaS:Ce, Sm and SrS:Eu, Sm that exhibit optically stimulated luminescence (OSL). The range of the dosimeter is from 0.01 to 1000Gy. The optically stimulated luminescent (OSL) radiation dosimeter technically surveys a wide dynamic measurement range and a high sensitivity. The equipment is relatively simple and small in size, and has low power consumption. This device is suitable for measuring the space radiation dose; it also can be used in high radiation dose condition and other dangerous radiation occasions.

Microbatteries are essential for portable electronics, cellular phones and MEMs devices to be miniaturized. Use of radioisotopes to realize nuclear microbatteries have been extensively researched. Electrical energy of a nuclear battery is produced from radioactive materials decaying by a suitable energy conversion process. Our approach in this paper is study of a direct collected charge to motion conversion. In this manuscript, the performance of radioisotope powered piezoelectric generator has been analyzed and simulated. The generator employs direct charging to convert radiated beta particles kinetic energy into stored electromechanical energy in a piezoelectric unimorph piezoelectricity to stored mechanical energy into extractable electrical energy.

In order to meet the rising demand for fuel leak detection and Dry Cask Storage Services, Westinghouse Electric Company chose to re-design and market the industry-proven failed fuel detection technique of canister sipping. Based on a custom fast-plastic scintillator gamma detector, Westinghouse chose simply not to re-build its legacy system. Instead, the system was redesigned from the ground up, considering materials, limitation of overall size and weight, system control, ease of use, and decontamination. The result was a brand new design and unique improvements utilizing new, yet proven technologies. The following paper will illustrate the considerations that engineering undertook while in development of the new system. These include industry lessons learned and the fundamental improvements considered. New aspects of the design will be highlighted, including steps to be taken to improve ease of decontamination, a unique sliding lid, Nuclear Instrument Module (NIM-Bin) replacement electronics, and an up-ending system. Steps taken to decrease weight and overall footprint size will be illustrated. Lastly, improvements in control structure, and a highlight of WeSiP, Westinghouse’s new object-oriented Global Sipping Platform Software, used to log data and power the system will be examined. With these unique improvements, the new Westinghouse Canister Sipping System meets the industry’s demands for a reliable system to identify failed fuel.

Narrow channel heat transfer element has been extensive adopted in engineering applications, especially at electronics technology, this kind of elements often be used to construct compact heat exchanger. Pressure drop of flow boiling at vertical channel with gaps of 1.7, 2.2 and 3.6 mm was experimentally investigated in this paper. The variation of the two-phase frictional multiplier vs. heat flux at various operating conditions was gotten experimentally, possible mechanism of the two-phase frictional multiplier trends of narrow channel were analyzed. Experimental results revealed that the two-phase frictional multiplier increased at lower flow rate and heat flux, as well as higher vapor quality, and dropped at wider flow gap. The multiplier can not be estimated by commonly used method for ordinary gap, thus a modified model of pressure drop for narrow channel was proposed considering the size effects of channel. The error of the predicted two-phase frictional multiplier is within ±15.4% compared with experimental results.

A clear distinction between advanced plants, such as the Westinghouse AP1000 and AP600, and evolutionary plants is the policy in the latter to use current systems’ and buildings’ configurations. This approach does not promote simplification or streamlining, especially in the mechanical systems of the plant. The most significant simplification in evolutionary designs has arguably been in the plant electronics where compact digital components and multiplexing have led to improvements, especially in the areas of information display, installation, and testing. The Westinghouse advanced, passive plants take a different approach. Their design engineers presume that if regulatory requirements can be satisfied by using passive systems, then active plant systems that are only designed to meet plant control functions and not burdened with meeting a safety pedigree can be implemented. This separation of safety and control allows the plant designer to focus on systems’ optimization and reliability by reducing complexity and its associated cost. This design policy has led Westinghouse to the AP600 and AP1000 plant configurations, both of which incorporate significant improvements in areas of plant simplification and enhanced safety.