Evolution of Standardized Specifications on Materials, Manufacturing and In-Service Inspection of Nuclear Reactor Vessels

The cataloguing and revision of reactor pressure vessels (RPV) manufacturing and in-service inspection codes and their standardized material specifications—as a technical heritage—are essential for understanding the historical evolution of criteria and for enabling the comparison of the various national regulations, integrating the most relevant results from the scientific research. The analysis of the development of documents including standardized requirements and the comparison of regulations is crucial to be able to implement learned lessons and comprehend the progress of increasingly stringent safety criteria, contributing to sustainable nuclear power generation in the future. A novel methodology is presented in this work where a thorough review of the regulations and technical codes for the manufacture and in-service inspection of RPVs, considering the implementation of scientific advances, is performed. In addition, an analysis focused on the differences between irradiation embrittlement prediction models and acceptance criteria for detected defects (both during manufacturing and in-service inspection) described by the different technical codes as required by different national regulations such as American, German, French or Russian is performed. The most stringent materials requirements for RPV manufacturing are provided by the American and German codes. The French code is the most stringent with respect to the reference defect size using as a criterion in the in-service inspection.

Grid-Scale Ternary-Pumped Thermal Electricity Storage for Flexible Operation of Nuclear Power Generation under High Penetration of Renewable Energy Sources

In this work, the integration of a grid-scale ternary-Pumped Thermal Electricity Storage (t-PTES) with a nuclear power generation to enhance operation flexibility is assessed using physics-based models and digital real time simulation. A part of the electricity from the nuclear power generation is delivered to the grid, and the balance is used to power a heat pump that can be augmented by an auxiliary resistive load element to increase the charging rate of the thermal storage. This increases the thermal potential between hot and cold thermal stores (usually solid materials or molten salts inside large storage tanks). The thermal energy is transformed back into electricity by reversing the heat pump cycle. Different transient scenarios including startup, shutdown, and power change for grid-connected operation are simulated to determine the behavior of the hybrid nuclear-t-PTES system operating under variable loads that constitute a departure from conventional, baseload nuclear plant operation schemes. Ternary refers to the three modes operation: (i) heat pump (including heating coil), (ii) heat engine, and (iii) simultaneous operation of heat pump (including heating coil) and heat engine during changeover from pumping to generation or vice-versa. The controllability of t-PTES in the short timescales as a dynamic load is used to demonstrate operational flexibility of hybrid nuclear plants for flexible operation through advanced load management. The integration of t-PTES into nuclear power systems enhances the system flexibility and is an enabler for high penetration of renewable energy resources.

Tele-operation of an industrial robot by an arm exoskeleton for peg-in-hole operation using immersive environments

The design and development of an upper limb exoskeleton are being discussed for the tele-operation in order to control the KUKA KR5 industrial robot. When sufficient resolution is not provided by the visual feedback, feedback of haptic provides a qualitative understanding of changes in the remote conditions. This also provides tactile feedback from the virtual and real environment. Peg in a hole operation using exoskeleton works as the master for tele-operation in order to control the robot using immersive environment as visual feedback for the operator. The application of this work can be implemented as a nuclear power generation plant.

Measuring CSR Disclosure when Assessing Stock Market Effects

A growing number of studies use a dichotomous variable indicating the presence of a standalone CSR report to capture impacts of CSR disclosure. Our concern is that, without considering differences in the information provided, such an approach could lead to incorrect inferences regarding those impacts. Accordingly, we extend prior research by examining whether, similar to differences in environmental disclosure, the mere presence of a standalone CSR report mitigates negative market reactions at times of regulatory cost exposure. We focus on the 2011 Fukushima Daiichi disaster and a sample of international utilities with nuclear power generation. Controlling for other factors related to social and regulatory cost exposures, we find only the environmental disclosures appear to reduce negative market effects. We thus argue that, in exploring the impacts of CSR disclosure, researchers need to carefully consider, beyond just the presence of a CSR report, differences in the extent of information being provided.