Abstracts - VGB PowerTech Journal 5/2009

DAtF 2009 Winter Meeting: Opening Address – Responsibility for Germany's Energy Supply

Walter Hohlefelder

Responsibility for energy supply concerns all stakeholders – politics, suppliers, and consumers – and requires unbiased analysis, realistic planning, and courageous commitment. We are facing enormous challenges. The life extension of German nuclear power plants is an adjunct of a sustainable economic programme, all the more so as it will not cost the taxpayer one cent.
DAtF 2009 Winter Meeting: Opening Address - Responsibility for Germany's Energy Supply

Walter Hohlefelder

Responsibility for energy supply concerns all stakeholders - politics, suppliers, and consumers - and requires unbiased analysis, realistic planning, and courageous commitment. We are facing enormous challenges. The life extension of German nuclear power plants is an adjunct of a sustainable economic programme, all the more so as it will not cost the taxpayer one cent.
Operating Experiences with Nuclear Power Plants 2008
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 2008 as well as on safety-relevant events, important repair measures, special retrofit measures and annual dose rates.

Nuclear Knowledge Management - A Core Competence of VGB

Hartmut Pamme

It is a well established expectation that utilities/operators of nuclear power plants communicate their own operational situation and are able to comment promptly on any findings and events in the international nuclear scene. In order to gain synergies on knowledge management, utilities have been using VGB as common platform for many years. The paper describes the generic expectations concerning knowledge management towards an association like VGB. It is analysed which elements and peculiarities of modern knowledge management are already established within VGB in the nuclear field.

Design and Operating Condition Consequences for EDF NPP's Chemistry

Jean-Luc Bretelle, Agnés Stutzmann and Francis Nordmann

Since the beginning of the French nuclear programme in 1977, four major types of design have been commissioned, the fifth one being under construction (EPR). The paper points out advantages and drawbacks of chemistry choices for the primary, secondary and tertiary systems in French NPP, for each design particularity and it describes the corresponding operating conditions. Chemistry option proposals are drawn for the future of the French fleet, taking into account the material behaviour and the operation improvement.

Development of a Corrosion Product Management for the Secondary Circuit of the NPP Beznau

Hartmut Venz and Irene Mailand

After having replaced the steam generator and related components in the Beznau power plant and after having optimised the water chemistry, a corrosion product management system was developed that proved to be a suitable tool to assess the condition and possible corrosion risks of the steam generator and all other important components of the secondary cycle. Based on the major target, i.e. never having to clean the system chemically, other important targets are also being focused on.

Blow-down of WWER-440 Steam Generators in NPP Paks

Janos Ösz

The article locates the concentration places of non-volatile solutes and accumulation places of disperse corrosion products in WWER-440 steam generator, based on the simulated two-phase flow illustration. The take-away from these places results in effective blow-down under the operation of new SGs. Furthermore, the article concludes that the blow-down of SGs in the Paks NPP - that operate with high purity working medium - can be less effective than new SG under the enlarged power of extended lifetime. The annual blow-down is replaced by periodic blow-down. In the meantime the daily average hourly mass flow and the continuous blow-down are unchanged.

The Areva Integrated and Sustainable Concept of Fatigue Design, Monitoring and Re-assessment

Jürgen Rudolph and Steffen Bergholz

Fatigue is a focus of Areva's R&D activities in the view of changing boundary conditions for the operation of nuclear power plants: modification of the code-based approaches, lifetime extension, new plants with scheduled operating periods of 60 years and improvement of availability. An integrated approach to the fatigue issue is the way to an optimisation of costs and plant operation as well as a minimisation of non-destructive testing requirements.

Dynamic Optimisation Technology Improves Unit Performance during Times of Changing Demand

Jeffery Williams

The paper describes how "add-on" technologies applied to existing power station control systems can help meet a changing supply and demand market, improving efficiencies and increasing revenues for plant operators. The increasing use of wind power as a contributor to generating capacity is challenging operators to improve the response of their base capacity to match rapidly fluctuating supply and demand conditions. In order to meet the requirements new software modules have been developed for existing control systems that enhance boiler and turbine response for tighter overall control and more efficient operation.

Influence of Z-phase on Long-term Creep Stability of Martensitic 9 to 12 % Cr Steels

Hilmar K. Danielsen and John Hald

The long-term creep strength of the new generation of martensitic creep resistant 9 to 12 % Cr steels is based on the well-known steel Grade 91. Careful control of the Z-phase precipitation process has led to the design of experimental 12 %Cr martensitic steels. Such steels may again enable the combination of high strength and oxidation resistance in the same alloy. This opens a new pathway for further alloy development of the heat-resistant martensitic steels.

Microbially Influenced Corrosion in Cooling Water Systems - Development of a New Protection Concept for System Components Conveying Brackish Water

Simone Bartels, Erika Nowak and Tobias Richter

Corrosive findings ascribed to Microbially Influenced Corrosion (MIC), have been increasingly observed on cooling water systems in Northern German nuclear power plants. By means of a research programme (field tests), high-alloyed materials with different Pitting Resistance Equivalent Numbers (PREN), various surface finishing and various coatings were evaluated, based on microbiological preliminary research, with respect to their corrosion behaviour in natural brackish water. Subsequent material evaluations, in combination with other measures, provided a new standard of knowledge for the development of a protection concept for components conveying brackish water.

A Systematic Approach Linking Condenser Performance to Heat Rate and CO2 Emissions

Peter de Graaf, Martyn Gilbert and Andrew Hurst

A systematic approach to cooling system management was taken at InterGen's Rocksavage Power Station with the objective of improving the overall performance of the cooling tower and condenser under varying conditions. The approach included a combination of engineering, operational and chemistry initiatives that led to measurable performance improvements. This paper will present the path taken by the Rocksavage Power Station to not only improve condenser performance, but also to quantify the impact on plant heat rate and CO2 emissions.

Water Desalination with Membrane Methods - The Revised VGB Instruction Sheet M 404

Gerd Pohsner, Joachim Fahlke, Jörg Klauer, Michael Lormies and Jochen Staiger

The VGB Instruction Sheet M404G "Water Desalination with Membrane Methods" has been revised by the VGB Working Group "Chemistry of Water Treatment". Central issues like the description of membrane and module types have been updated as well as some process engineering details. A new chapter about electro deionisation (EDI) has been introduced. A so-called "design matrix" has been developed. It is for use as a clearly arranged presentation of process engineering possibilities for an optimum design of the treatment steps, depending on the quality of the relevant inlet water at the respective step. A chapter about automation has also been introduced.