Abstracts - VGB PowerTech Journal 5/2007

Opening Address, 2007 Winter Meeting

Walter Hohlefelder

Even more so than last year, energy policy is at the very top of the political agenda. The European Commission presented its strategy paper on “One Energy Policy for Europe,” and another energy summit will be held in Germany to pave the way for an energy concept.
As far as nuclear power is concerned, the EU Commission clearly and soberly emphasized today’s contribution of nuclear power in the EU and, above all, the chances of further expanding the use of nuclear power in the interest of CO2 avoidance, security of supply and competitiveness. This makes a reassessment of nuclear power also a matter of national interest.

Operating Experience with Nuclear Power Plants 2006

VGB-Fachausschuss Kernkraftwerksbetrieb

For more than 30 years the VGB Technical Committee “Nuclear Power Plant Operation“ has been exchanging operating experience made in nuclear power plants. Nuclear power plants from Germany, Finland, France the Netherlands, Sweden, Switzerland and Spain participate in this exchange. A report is given on the operating results obtained in 2006 as well as on safety-relevant events, important repair measures, special retrofit measures and annual dose rates.

When Future Becomes Reality: Investments in New Nuclear Power Plants

Laurent Stricker

A strong interest towards nuclear energy is shown in countries such as the United States, India and China. A specific highlight is made on Europe. As some European countries do not intend to implement a new energy mix with nuclear options, Finland is building a European Pressurised Reactor in Olkiluoto (OL 3), while the United Kingdom is shutting down several old nuclear plants, and thinking of building some new ones. This paper also gives some details about the situation in France, where a large nuclear fleet is operated. The renewal of the existing fleet was studied through two different scenarios, including Generation III and Generation IV Nuclear Power Plants.

20th Anniversary of the KSG/GfS Simulator Centre!

Eberhard Hoffmann

20 years ago, the two companies KSG Kraftwerks-Simulator-Gesellschaft mbH and GfS Gesellschaft für Simulatorschulung mbH were founded for the operation of simulators and their use for the training of responsible nuclear power plant personnel. A Simulator Centre had been installed, which looks back on a period of successful training and enormous development. The Simulator Centre is a joint enterprise, a competence centre and a service centre at the same time. This article reflects these demands and their realization and describes the relevant developments and experiences.

Recent Experience about the Influence of Primary Coolant and Shutdown Chemistry on Cobalt Activity at the Beznau NPP

Irene Mailand and Hartmut Venz

The Beznau nuclear power plant comprises two identical 380 MWe PWR units, commissioned in 1969 and 1971. The surfaces of the new steam generator tube material, Inconel 690, are the main source of 58Co. The 60Co originates predominantly from the Cobalt alloy, Stellite, which is installed in valves and pump bearings because of the very good hardness of this material. By means of optimised shutdown chemistry it is possible to reduce the amount of NiO on the fuel rods, leading to reduced Co-58 peaks in subsequent cycles. The optimised shutdown chemistry during the past few years and especially the strict separation of acidreducing phase from the acid-oxidising phase as well as the results of studies and the resulting operational experiences are important basics for the actual operation mode of the Beznau NPP.

Tracer Test Method and Process Data Reconciliation Based on VDI 2048 – Comparison of two Methods for Highly Accurate Determination of Feedwater Mass Flow at the Beznau NPP

Thomas Hungerbühler, Magnus Langenstein

The feedwater mass flow is the key measured variable used to determine the thermal reactor output in a nuclear power plant. Usually this parameter is recorded via venturi nozzles or orifice plates. The problem with both principles of measurement, however, is that an accuracy of below 1 % cannot be reached. In order to make more accurate statements about the feedwater amounts recirculated in the water-steam cycle, tracer measurements that offer an accuracy of up to 0.2 % are used. In the NPP Beznau both methods have been used in parallel to determine the feedwater flow rates in 2004 (unit 1) and 2005 (unit 2). Comparison of the results shows that a high level of agreement is obtained between the results of the reconciliation and the results of the tracer measurements. As a result of the findings of this comparison, a high level of acceptance of process data reconciliation based on VDI 2048 was achieved.

Perspective and Projects for a Sustainable Electricity Future in India

Yogeswhar Singh Ratra, Harinder Mohan Jain

The growth in electricity demand in India over the last 5 to 10 years has been sizeable, whereas matching capacity addition has been lacking resulting in both energy and peak demand shortages. To meet with projected requirements fully over the next 5 to 6 years, new initiatives in capacity addition of about 68,000 MW are called for. The paper covers historical perspective of growth of the Indian power sector detailing current and projected scenario of installed capacity, per capita consumption of electricity, village and household electrification and source-wise contribution in the electricity generation along with present supply position and demand projections. The development of a National Power Grid in India is another important issue that finds mention. The paper further highlights various provisions of the Electricity Act 2003 in the field of Power Sector Reforms and raising level of competition in power sector to ensure increased private sector participation.

Maintenance in Competition: Experience with OEM and Non-OEM upon Maintenance of Gas- and Steam Turbine Generators

Klaus Schippers, Andreas Hinterthan, Bruno Schroeder and Oliver Then

Due to the enormous increase in competition within the electricity industry it has been necessary for Energy Utilities to significantly reduce their controllably costs. A proportion of these cost reductions have been made in the area of power station maintenance activities and have in part been achieved through increasing the inspection and maintenance intervals of major plant components and through the increased use of third party maintenance service providers. This report describes the ongoing development of the gas and steam turbo-alternator maintenance strategy within the hard coal-fired and gas-fired power stations of RWE Power.

Experience from Straw Dust Firing at Amager Unit 2

Mogens Berg, Soren Thaaning Pedersen, Gorm Rohde

Due to CO2 regulations, the power companies in Denmark have to increase the amount of biomass. Additional to the firing of straw bales, wood pellets and wood chips also straw pellets have been introduced as a biomass fuel to be fired in the old pulverised coal-fired unit, Amager. Operating experience and problems caused by the new fuel are outlined and discussed.

Innovative Coating and Heat Insulation of e. g. Waste Heat Recovery Steam Generators

Klaus Danwerth, Dietmar Ringkamp, Bruno Wilhelmi, Georg Krömer

The waste gas ducts of a combined-cycle power plant were conventionally isolated with mineral wool mats and internal metal sheet cladding. This isolation caused problems already during the first months of operation. After presentation of a new technique for international insulation of waste gas ducts it was decide to set up a test field in the waste gas duct and to collect first operating experience. After nearly one year of operation the system displayed excellent insulation characteristics. In comparison to conventional internal isolation, the Compac Clad system better meets the requirements of a nearly gastight insulation.

Quality of Forecast of Noise Emissions in Industrial Plants

Josef Danner

On the basis of a virtual industrial plant, a calculation method is presented. By means of this method, the uncertainties of sound sources of an industrial plant can be weighted. It shows that the largest uncertainties occur for estimating the sound emission of individual sources. Therefore, the uncertainty and thus the quality of the noise prediction decisively depend on the competence of the acoustic expert. Thus, a statement of a tolerance is not really decisive for describing the quality of a prediction. More important are realistic approaches regarding the sound emission of individual sources.

Tail-end CO2 Capture as Convincing Opportunity for Retrofitting of Coal-fired Power Stations and Related R&D Objectives

Bernhard Epp, Hans Fahlenkamp, Bernhard Pieper, Christina Stankewitz, Egon Erich, Monika Vogt

CO2-capture techniques of the so-called post-combustion-category appear to be highly attractive. In the ideal case they can be simply “attached” to the well-proven power plant process. This publication outlines the concept of two recently started research projects, interrelating the experimental idea to a reasonable capture-ready-design. The experimental ideas are the use of hollow fibre (membrane)-contactors as absorption apparatus with flash-desorption of amine solutions as solvents and the operating of a mobile potash scrubber in the by-pass flue gas stream of commercially run power station.