Abstracts - VGB PowerTech Journal 5/2008

2008 Winter Meeting of Deutsches Atomforum: Opening Address

Walter Hohlefelder

On the global and European scenes, nuclear power is experiencing an upswing, while it continues to be blocked in Germany. Given the pressing issues of climate protection, continuity of energy supply, and the prices of energy resources, the future of nuclear power can well be seen in an optimistic light. There will be a reassessment of nuclear power also in Germany because of the realities to be faced. If you really want to protect the climate, you cannot exclude the nuclear power option.

Operating Experience with Nuclear Power Plants 2007

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.

Annual Shutdown Chemistry Instead of Decontamination

Hartmut Venz and Irene Mailand

Outages in nuclear power plant cause about 80 to 90 % of the personnel dose rate of nuclear power station staff. The values cane be minimised be reducing the dose rate of the surface of components of nuclear power systems. In the past a common measure was the application of chemical decontamination, in which not only the outer but also the inner corrosion product layers were nearly removed completely.

Alpha-nuclides in Nuclear Power Plants

Peter Zeh, Marcel Schienbein, Alois Bleier, Wolfgang Schwarz and Mathias Rosskamp

The behaviour of alpha-nuclides in nuclear power plants is subject of the investigations presented. The source of alpha-nuclides is a contamination with fissile material (so called tramp uranium or tramp fuel) which deposits on fuel rod surfaces and leads to the build-up of transuranium nuclides. The determination of a defect situation with fuel release as well as the quantification of the fissile material contamination background is given for BWR and PWR plants. The quantification of the fuel release and the tramp uranium background can be calculated with different, measurable nuclides in BWR and PWR plants.

Evaluation of Linearly Elastic Finite Element Analyses in the Context of Mechanical and Thermo-mechanical Stresses

Jürgen Rudolph and Steffen Bergholz

Classical linearly elastic stress analysis can still be considered a principal practical application of the finite element (FE) method. It is in close relationship to problems of stress categorisation and evaluation according to the considered load case. The aim of the paper is to provide practical guidelines using concrete examples of power plant components subjected to mechanical and thermo-mechanical loadings.

Highly-efficient Lingen Combined Cycle Power Plant: Integration of the Recent GT26-Technology

Johannes Lambertz, Manfred Kehr and Andreas Lusch

Even after the third Energy Summit and the adoption of NAP II, the political framework for new investment in the power generation market remains uncertain. Key issues like the CO2 regime after 2012, the expansion of renewables-based generation and the growing dependence on imported primary energy are unresolved. Despite these uncertainties, the Lingen CCGT plant contributes to maintaining a well-balanced primary energy mix of RWE Power. It supplements the portfolio in the intermediate- and peak-load segment that is in great demand and is a building block of RWE Power's current power plant renewal and modernisation programme.

Status and Perspectives of Renewables in South East Europe

Joze Zagozen, Damjana Raner and Djordje Zebeljan

Slovenia is a small but well interconnected electricity market. Market developments in SE Europe will continue to strongly influence the Slovenian electricity market and electricity prices. In the medium term a worsening of electricity market balances in the regional market can be expected. This trend can only be stopped through the construction of a significant number of proposed projects regarding new generation units.

Energy Efficiency of Geothermal Power Generation

Alfons Kather, Kathrin Rohloff and Andreas Filleböck

The paper presents and analyses the possibilities of process optimisation und benchmarking of low-temperature electricity generation based on geothermal energy by taking into account own station demand of the entire plant. The processes available are presented in a new, generally valid structure. Efficiency and utilisation degrees are partly defined anew in order to be able to differentiate between cycle losses and entire plant losses. These are applied to different plant arrangements.

Failure Analysis with Advanced Simulation Techniques

Axel Schulz and Lars Sitzki

Advanced simulation techniques allow proving contrary to the traditional approach the truth of the failure assumption. Within the simulation the component is exposed to the exact assumed failure loads. This process represents an inversion of the causal chain. The iterative nature of this method allows a quasi-causal approach. The failure assumption is continually revised until the results of the simulation are equivalent to the damage symptoms.

Synthetic Natural Gas from Solid Biofuels - A Technical Analysis

Stefan Rönsch, Moritz Dreher, Alexander Vogel and Martin Kaltschmitt

Bio-fuels can be provided as liquids (e.g. Fischer-Tropsch-Diesel, Methanol) but also as gases (e.g. bio-methane, Synthetic-Natural Gas, Bio-SNG). The possibilities and limits of the latter are analysed from a technical point of view. The conversion path from solid biomass to Bio-SNG is a promising option.

Application of Biocompounds for the Purification of Regenerates Containing Nitrogen Taken from Condensate Cleaning Systems

Regina Walter, Kai Büsching, Christian Böttger, Nadine Oswald and Clemens Ochmann

Using the Biocompound technique, it is possible to biologically purify the regenerates of condensate cleaning systems to ensure direct discharger quality. In this process simultaneous nitrification and de-nitrification can take place temporally and locally using a completely aerated fluidised bed reactor. The biofilm carriers used for this purpose contain two different readily bio-degradable bio-polymers, the so-called Biocompounds.