Abstracts - VGB PowerTech Journal 5/2012

Operating experience with nuclear power plants 2011

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 2011, events important to plant safety, special and relevant repair and retrofit measures from Belgium, Germany, Finland, the Netherlands, Switzerland and Spain.

The load follow capability of nuclear power plants - experience and outlook

Wolfgang Timpf and Michael Fuchs

The notion that nuclear power plants are inflexible machines that cannot be operated in load-following mode has constantly been spread by anti-nuclear activists over the last years. But actually, quite the opposite is true. Nuclear power plants are able to adjust their power output over a wide range within a short period of time. High power flexibility was already implemented into the original design of German nuclear power plants from the very beginning and has not to be retrofitted.

Replacement of the cooling tower packing at the Gösgen-Däniken AG nuclear power plant

Hans Walter Rich

In 2005 the asbestos cement cooling tower packing was replaced by plastic material. Two years later, the packing showed strong deformations, deposits of solids and weight gain. At the end of 2007 parts of the packing collapsed into the cooling tower basin. Investigations were made, revealing that the thickness of the packing foil was too low and that packing geometry and biofilms on the surface of the packing favoured deposition of solids. Successful measures were taken to solve the problems.

Advances cycle based fatigue - a stress and temperature based synthesis of existing basic approaches

Christian Heinze, Jürgen Rudolph, Steffen Bergholz, Benoit Jouan and Martin Reithinger

Cycle based counting is an internationally established procedure for the determination of fatigue usage factors in nuclear power plants. The AREVA fatigue concept (AFC) includes a three-stage approach to calculate the usage factors, utilising not only cycle based counting but additionally stress based fatigue analysis. This paper describes the developed Advanced Cycle Based Fatigue method (A-CBF) that uses not only the measured temperature profile but also the stresses previously calculated in the three stage approach of the AFC.

Alternative solutions for waste management centres designed for new nuclear power plants under construction

Klaus Büttner

Today, designers of new VVER reactors as well as Russian NPP operating companies favour direct methods of waste management for treating wastes of different categories generated during plant operation. The objective is to achieve the amount of 50 m3 of conditioned waste per one reactor unit per year, which is currently being discussed internationally. NUKEM Technologies has reviewed the existing waste management concepts and proposed improved waste management technologies.

Rebuilding the synchronous generator of the Biblis A NPP to a phase-shifting motor

Martin Lösing and Georg Schneider

After the disconnection of the power plant Biblis through the KKW-Moratorium 2011 the infeed of reactive power in the area around Frankfurt has been too low. With the rebuilding of the synchronous generator Biblis A into a synchronous motor (synchronous condenser) an adaptable and automatically regulated large reactive power compensation is available for supporting the grid voltage.

Energy storage: technologies and potentials to balance supply and demand of energy

Markus Doll and Jörg Kruhl

Following political and public intention, future energy systems will be based on a high share of renewable energy with fluctuating behaviour. This will lead to system states in which the matching of supply and demand will be a main challenge. Energy storage is one measure to overcome this challenge. However, energy storage is not the only solution, there are alternative measures such as grid extension, load management or building backup capacity. This paper will present the existing and new storage technologies with their specific application areas and opportunities. The focus is on the large-scale storage applications in Germany.

Projects for pumped storage plants - a new battery for Europe

Andreas Stettler

Today, more than 11 pumped storage plants (PSP) with a collective pump capacity of 1,600 MW are located in Switzerland. In future, Europe’s ambitious plans to expand the share of renewable energy will require much larger systems which are capable of regulating or even buffering intermittent feed-in. Swiss electrical utilities were quick to recognise this need and are now increasingly exploiting their ideal alpine topography for this purpose. The capacity of an existing PSP on the shores of Lake Geneva is currently being doubled, and the Nant de Drance and Linth-Limmern projects are under construction. If these expansion projects are to play a key role as part of Europe’s battery, transmission grids on Europe’s North-South axis must be expanded without delay.

Flexibility through highly-efficient technology

Roland Jeschke, Björn Henning and Wolfgang Schreier

Increasing renewable energy generation urges the conventional counterpart to secure grid stability by balancing fluctuating input. Conventional power plants therefore need to become more flexible in terms of load range, frequent start-up and shutdown capability with keeping emission limits and part load efficiency to assure the maximum input of renewable generation. Hitachi Power Europe GmbH provides several means to improve power plant flexibility cost effectively by combining existing technologies reasonably.

12 years of Fuzzy on the example of the Ludwigshafen waste incineration plant - What is possible and what is not?

Heinrich Maltry, Christian Gierend and Uwe Schneider

TWL as the operator of the Ludwigshafen WTE plant, site of GML, decided in 1999 on reviewing the firing rate control at boiler 3 which had required many manual interventions by operating personnel. During the period 2003 to 2009, the flue gas cleaning lines were switched to “quasi dry” operation and the waste boiler was switched to Fuzzy control.

How the right chemistry in the FGD unit helps to improve the removal in the waste water treatment plant

Leo Vredenbregt

The chemistry in the wet flue gas desulphurisation (FGD) unit is complex and far from constant, depending on fuel composition and flue gas conditions. Trace elements that exist in several oxidation states and which are of environmental importance are As, Cr, Hg, Mn, Se, Sb and Tl. From results with “jar tests”, in which the wastewater treatment plant (WWTP) is simulated, it becomes clear that the removal in the WWTP cannot be optimal for all elements at the same time at certain ORP conditions in the FGD.

Method against increasing chemical costs due to ageing resins in IEX DI plants

Dieter Mauer

It is a familiar but unwelcome fact in ion-exchange DI systems that the loading throughput decreases with increasing age of the resin filling. In this paper, the reasons and consequences will be outlined which cause improper response to these phenomena.
New strategies for the adaption of regenerant amounts emerge from the understanding of the specific ion-exchange aging mechanisms and the influence on the operating capacity by variations of regenerant amounts for thoroughfare regeneration and one-stage counter-current regeneration.