Design of High Power Regenerative Battery Discharger System for Nuclear Power Plant

In a Nuclear Power reactor, safety loads are backed by standby battery system. The healthiness of the battery is very essential requirement and prominent attention is given to availability and reliability of battery supply in nuclear plants. Hence regular monitoring and testing the performance of the battery is a prime requirement. The capacity and load cycle discharge testing of the battery is done annually and the current system employed is to discharge the battery current through resistor banks, which results in unusable power consumption and is uneconomical. The growing trend in power electronics field has given the new technology of regenerating the dissipated power to grid. This paper proposes a high power electronic regenerative technology with high efficiency, low harmonics to pump the dc power to the grid. Though, it is available at lower rating in industry, the paper proposes a high power regenerative discharge system. The topology selected is interleaved boost converter interfaced to a three phase grid connected inverter. The challenges involved are high power operation, steep current discharges with a minimal interference to the normal plant operation power supplies during the regeneration. This paper also presents the system design and simulation results.

A Review Paper on Importance of SHM System in India

India being the home of rich historical background inherits varied amount of historical structures like Taj Mahal (one of the seven wonders), Red fort, Temples etc. Due to their historical importance, it becomes very important to assess health condition of these structures and take the required measures to improve their life. Buildings like stadiums, sports arenas, malls, lifeline structures like hospitals, public buildings which could cause harm to large number of people at a time and are something to be taken care on a regular basis. India also has various ambitious, complex, and critical structure, like nuclear plants, Dams, bridges and tunnels should be mandated with monitoring as their failure cause more losses than any other. Structural health monitoring will help us to achieve increased durability and health of structure, reduced maintenance and improved safety. Health monitoring of civil infrastructures consists of determining by measured parameter, the location and severity of damage in structures and inform us before it became to late. The main goal of SHM is to detect the damage based on the measurement by various types of sensors, locate the geometric position of the damage and quantify the damage so that we can take the necessary action timely and improve the life of the structure. Keywords: Bridge, Structural Health Monitoring (SHM), sensors, data management system, instrumentation scheme, Performance parameters

PLCrypto: A Symmetric Cryptographic Library for Programmable Logic Controllers

Programmable Logic Controllers (PLCs) are control devices widely used in industrial automation. They can be found in critical infrastructures like power grids, water systems, nuclear plants, manufacturing systems, etc. This paper introduces PLCrypto, a software cryptographic library that implements lightweight symmetric cryptographic algorithms for PLCs using a standard PLC programming language called structured text (ST). To the best of our knowledge, PLCrypto is the first ST-based cryptographic library that is executable on commercial off-the-shelf PLCs. PLCrypto includes a wide range of commonly used algorithms, totaling ten algorithms, including one-way functions, message authentication codes, hash functions, block ciphers, and pseudo-random functions/generators. PLCrypto can be used to protect the confidentiality and integrity of data on PLCs without additional hardware or firmware modification. This paper also presents general optimization methodologies and techniques used in PLCrypto for implementing primitive operations like bit-shifting/rotation, substitution, and permutation. The optimization tricks we distilled from our practice can also guide future implementation of other computationheavy programs on PLCs. To demonstrate a use case of PLCrypto in practice, we further realize a cryptographic protocol called proof of aliveness as a case study. We benchmarked the algorithms and protocols in PLCrypto on a commercial PLC, Allen Bradley ControlLogix 5571, which is widely used in the real world. Also, we make our source codes publicly available, so plant operators can freely deploy our library in practice.

The Specific Characteristics of Shock and Blast Impacts on Construction Sites

The practices of hazardous and unique facilities’ construction imply that specific attention is paid to the issues of safety. Threats associated with crash impacts caused by moving cars or planes are considered. To ensure safety of these construction sites it is required to know the potential dynamic loads and their destructive capacity. This article considers the methodology of reducing dynamic loads associated with impacts caused by moving collapsing solids and blast loads to equivalent static loads. It is demonstrated that practically used methods of reduction of dynamic loads to static loads are based in schematization only of the positive phase of a dynamic load in a triangle forms are not always correct and true. The historical roots of this approach which is not correct nowadays are shown; such approach considered a detonation explosion as a source of dynamic load, including TNT and even a nuclear weapon. Application of the existing practices of reduction of dynamic load to static load for accidental explosions in the atmosphere that occur in deflagration mode with a significant vacuumization phase may cause crucial distortion of predicted loads for the construction sites. This circumstance may become a matter of specific importance at calculations of potential hazard of impacts and explosions in unique units — for instance, in the nuclear plants. The article considers a situation with a plane crash, the building structure load parameters generated at the impact caused by a plane impact and the following deflagration explosion of fuel vapors are determined.

Design of a dynamic mock-up bench for testing robotic interventions

When a robotic intervention is required in hazardous facilities (e.g. particle accelerators or nuclear plants), it is commonly not possible to test the operation on-site in advance - a considerable challenge since robotic interventions usually require specific tasks for each location -, precluding the team from demonstrating the feasibility of the operation. It becomes mandatory to develop a particular mock-up for each operation, unsuitable for reusing it in future missions. To solve this problem, a general dynamic mock-up bench was designed, allowing to centre the testing of all remote handled tasks and to choose the best set of robots to perform them.

Energy and Local Safety: How the Administration Limits Energy Security

Energy safety is multifaceted and is not limited only to nuclear plants. The research on local energy safety is not considerable. This article creates new ground by analysing the Polish local energy safety system in the cause–effect context. Consistent with an abductive approach, this paper’s insights have emerged iteratively based on the theory reviewed and the empirical case. The research aimed to determine whether the local administration negatively affected energy security and proposed preventive measures increased limited energy security. The findings show that flawed local government operations reduce local energy safety. Moreover, the State authorities did not recognise the weaknesses of the local energy safety system properly. The findings make two main contributions: first, they contribute to developing energy safety theory; and second, this article contributes to a further contextual diagnosis of the comprehensive energy system and can, in turn, be relevant for its further studies in worldwide context.

Optimization of Maintenance Strategy for Sea Water Pumps in Nuclear Plants

Probabilistic Safety Analysis (PSA) methodology is a significant supplement to the deterministic safety analysis in the nuclear power plant. PSA can be used to evaluate the NPP device change, equipment maintenance, in service inspection. The practicability of modifying sea water pump maintenance programme is evaluated in this paper by determining the initial event probability in fault-tree and modifying the PSA calculation model. Based on the evaluation results, the preventive maintenance of sea water pump and 6kv switch can be changed from executed in the plant overhaul to executed in the routine maintenance. This could make a great contribution in optimizing the NPP sea water pump maintenance program.

Greater acceptability, lower compensations required? The impact of perceived net benefits on willingness to accept nuclear energy projects

Purpose This paper aims to estimate willingness to accept (WTA) hypothetical nuclear energy projects and the impact of net perceived benefits across three countries: Italy, a country without nuclear plants in operation; the UK, a country with nuclear plants in operation and the United Arab Emirates (UAE), which has more recently opted for the inclusion of nuclear energy in its energy mix. These valuations can support cost-benefit analyses by allowing policymakers to account for additional benefits and costs which would be otherwise neglected. Design/methodology/approach Data collection was conducted through online nationwide surveys, for a total of over 4,000 individuals sampled from Italy, the UK and the UAE. The surveys included choice experiments designed to elicit preferences towards nuclear energy in the form of WTA, indicating estimated compensations for welfare worsening changes and questions to measure perceived risks and benefits. Findings The average WTA/Km is the lowest for the case of the UAE. What is more, perceived net positive benefits tend to decrease the WTA required by the UAE respondents? Moreover, across the cases, albeit to a lesser extent with regard to Italy’s case, there is evidence that a more positive benefit perception seems to increase the valuation of environmental and public benefits offered as part of the experiment. Originality/value The contribution of this study is primarily twofold: first, it provides a comparison of WTA values in a context where the availability of choice experiment data is scant; second, it assesses whether and to what extent perceived net positive benefits of nuclear energy impact WTA of nuclear energy projects.