Abstract - VGB PowerTech Journal 5/2019
Not perhaps “nuclear energy for future” after all?
Dr-Ing Ludger Mohrbach
The only actually economic and available option for solving the energy challenge (until the introduction of nuclear fusion around 2050) is nuclear fission, currently used by 31 countries worldwide, with in five more newcomers under construction and four more in concrete planning. The nuclear fuels uranium and thorium are available worldwide for many centuries and for practically nothing else usable, with use in advanced reactors even for many thousands of years.[more...]
The role of resources and reserves for the global energy supply
The assured availability and competitiveness of the various energy sources, as well as climate compatibility, determine their use. Conditions on the energy markets are also subject to continuous change. This article examines the extent to which the availability of energy resources and the orientation of energy policies influence the energy mix, particularly power generation. It also outlines strategies for achieving the energy policy goals – security of supply, value for money and environmental compatibility (including climate protection) – in the best possible way.
Nuclear power plant flexibility at EDF
Patrick Morilhat, Stéphane Feutry, Christelle Lemaitre and Jean Melaine Favennec
Based upon existing experience feedback of French nuclear power plants operated by EDF (Electricité de France), this paper shows that flexible operation of nuclear reactors is possible and has been applied in France by EDF’s 58 reactors for more than 30 years without any noticeable or unmanageable impacts: no effects on safety or on the environment, and no noticeable additional maintenance costs, with an additional unplanned capability load factor estimated at only 0.5 %. EDF’s nuclear reactors have the capability to vary their output between 20 % and 100 % within 30 minutes, twice a day, when operating in load-following mode. Flexible operation requires sound plant design (safety margins, auxiliary equipment) and appropriate operator skills, and early modifications were made to the initial Westinghouse design to enable flexible operation (e.g., use of “grey” control rods to vary reactor core thermal power more rapidly than with conventional “black” control rods). The nominal capacities of the present power stations are sufficient, safe and adequate to balance generation against demand and allow renewables to be inserted intermittently, without any additional CO2 emissions. It is a clear demonstration of full complementarity between nuclear and renewable energies.
Targeting innovation at cost drivers – How the UK can deliver low cost, low carbon, commercially investable power
When it comes to creating affordable, reliable, low carbon energy, the UK consortium led by Rolls-Royce, is bringing a modern, holistic approach to small nuclear power station design. The design concept is driven by improving the economics and market requirements of nuclear power; targeting cost drivers such as schedule uncertainty; and focusing innovation efforts to reduce or remove those cost drivers entirely. The result is a compelling, commercially investible design for a whole power station, not just a small modular reactor, that can help the world meet its low carbon energy challenges.
The German Quiver Project – Quivers for damaged and non-standard fuel rods
Sascha Bechtel, Wolfgang Faber, Hagen Höfer, Frank Jüttemann, Martin Kaplik, Michael Köbl, Bernhard Kühne and Marc Verwerft
The GNS IQ® Integrated Quiver System is a versatile tool for the disposal of damaged fuel rods from both PWR- and BWR-NPPs. The Quivers can safely accommodate several fuel rods and – featuring the same dimensions as complete fuel elements – fit into the standard basket positions of the transport and storage casks for PWR-FA and for BWR-FA respectively. The Quivers are designed like a “second cladding” to accommodate large varieties of fuel rods with defects, e.g. in terms of deformations and defect morphologies, and also leakers. Their robust design provides sufficient margins for safety requirements. E.ON Kernkraft (EKK, now PreussenElektra) started a project in 2005 to establish a solution for the dry interim storage of their failed fuel rods in the on-site storage facilities. In 2006 EKK asked GNS Gesellschaft für Nuklear-Service mbH to join the project and later on further companies. In 2009 the four German utilities jointly asked GNS to take over one of the concepts and develop it towards cask-licensing. In 2018, the first PWR-quivers were loaded at Unterweser NPP. Further dispatch campaign are already in implementation.
Advanced sectorial gamma scanning for the radiological characterization of radioactive waste packages
M. Dürr, M. Fritzsche, K. Krycki, B. Hansmann, T. Hansmann, A. Havenith, D. Pasler and T. Hartmann
The management of radioactive waste is under strict regulatory control to ensure the compliance with safety guidelines. For the disposal in the Konrad geological repository for non-heat generating radioactive waste in Germany, acceptance criteria for radioactive waste packages have been derived from the safety case. The waste designated for disposal is subject to product control which is conditional for approval of the waste package by the operator of the disposal facility. The non-destructive assay using gamma radiation detection techniques is a cost-effective measure to characterize radioactive waste and serves to verify the conformity with the acceptance criteria. In the past decades, the pre-dominantly used method is segmented gamma scanning of waste drums, which is based on simplifying assumption of a uniformly distributed activity and a homogeneous waste matrix. The simplification reduces the accuracy of the measurement leading to large conservative estimates for the activity content which in turn leads to an excessive and inefficient exhaustion of activity limits for waste packages and to higher costs for disposal. An Advanced Sectorial Gamma Scanning (ASGS) method is developed, which includes a software module for the efficiency calculation of inhomogeneous activity distributions (ECIAD) to reconstruct the spatially resolved activity distribution from the acquired measurement data. This method can be applied for a wider range of the composition of the radioactive waste, which is of relevance in the qualification of legacy waste and the increasing stream of waste from decontamination and decommissioning of nuclear installations.
Review of the analytical methods used in nuclear decommissioning
Application vs. aspiration – an EU-wide survey of methods in radioanalytical chemistry
Alexandra K. Nothstein, Ursula Hoeppener-Kramar, Laura Aldave de las Heras and Benjamin C. Russell
The wave of decommissioning of nuclear facilities that Europe is facing now and in the near future requires a solid basis of efficient chemical and radiochemical analytical methods and capabilities. This study presents the results of a survey among European laboratories to summarize current practices, covering radionuclides, activity levels, sample types, and analytical instrumentation to create a clearer picture of the present status and future challenges. The results reflect the particularity of decommissioning, which requires analysis of a wide range of sample matrices. As a result, a wide variety of radioanalytical methods are deployed. However, gamma spectrometry, liquid scintillation counting and alpha spectrometry remain by far the dominant analytical methods. Despite the need for novel methods for specific nuclides, laboratories did not consider specialization or miniaturization of instruments as a focus for future developments. Rather, two types of challenges emerged most prominently: firstly, process optimization, such as improved and more integrated communication with customers and regulatory bodies and secondly, methodical improvements, such as the more widespread application of new technologies and enhanced availability of reference materials.
From Technical Documentation to the Information Space
Information for everyone – company-wide, digital, mobile
Digitization, industry 4.0, mobile computing, social selling and big data will influence the products of tomorrow and ultimately shape the development of our entire society. Information becomes the lubricant of our digital world. Companies need an intelligent concept for making their collected knowledge available to all areas of the company: At the touch of a button, up-to-date, digital and mobile. DOCUFY, manufacturer of professional software solutions for technical documentation, has developed a solution concept: the information space.
Operating experience with nuclear power plants 2018
The VGB Technical Committee “Nuclear Plant Operation” has been exchanging operating experience about nuclear power plants for more than 30 years. Plant operators from several European countries are participating in the exchange. A report is given on the operating results achieved in 2018, events important to plant safety, special and relevant repair, and retrofit measures.