Abstracts - VGB PowerTech Journal 5/2010
Operating Experiences with Nuclear Power Plants 2009
The VGB Technical Committee "Nuclear Plant Operation" has been exchanging for more than 30 years operating experience about nuclear power plants. Plant operators from several European countries are participating in this exchange. A report is given on the operating results achieved in 2009, events important to plant safety, special and relevant repair and retrofit measures from Belgium, Germany, Finland, the Netherlands, Switzerland and Spain.
Safety by Simulation
Simulator training is a key component in achieving and preserving the necessary expertise - also in the long term - of plant personnel that is required by the authorities, too. Thus, it is an important contribution to the safe operation of nuclear power plants. The Essen simulator centre is supported by five nuclear power plant operators. Here they established a joint enterprise which performs in one central place the duty of simulator training incumbent upon all nuclear power plants.
Seismic Design of Nuclear Power Plant Buildings
Hamid Sadegh-Azar and Andreas Garg
Nuclear power plants are built in a variety of countries and regions all over the world. Some of these regions show seismic activity. Consequently, seismic excitation is an important factor to be considered when designing these plants. The article summarises the basic principles of safe nuclear power plant design in seismically active regions. First, the safety concept underlying seismic design and the corresponding international safety requirements and guidelines are presented. Next, the analytical techniques and methods of computation are shown which can be used in designing for seismic events, and the conservative elements existing in the entire chain of computation are outlined.
Seismic Design of Nuclear Power Plant Components - Status and Trends
Fritz-Otto Henkel and Manfred Schalk
The report presents an overview about the present state of seismic design of plant components in Germany and in accordance with the German KTA 2201.4 rules, respectively. A discussion of the design objectives as part of the entire chain of nuclear power plant design is followed by an explanation of the systematic approach along the lines of KTA rule 2201.4, which is currently undergoing revision. The impacts on site or at the place of installation are determined, and special reference is made to possible methods of design and demonstration: computational and experimental approaches as well as analogy and plausibility procedures. The processes are explained and attention is drawn to inherent conservative factors. Knowledge of these factors in particular is of immense importance within the framework of a seismic PSA as part of a PSR. Reserves are apparent also from considering seismic design in the light of plant behaviour in real-life earthquakes. The report shows how revision of KTA 2201.4 re-establishes the connection to the international state of the art by opening the concept to more realistic procedures.
The Operation Supply of EnKK - Implementation of the Hazardous Substances Regulations, Handling of Materials
Bernhard Lehmann, Fred Böttcher and Michael Bolz
The materials management system of EnKK combines the purchasing, approval and quality assurance processes of material supply items with the requirements concerning the protection of health and the environment. The data and processes concerning procurement are connected to the material specific database by means of an SAP database system. The implementation and performance of the system made an important contribution to the positive results during the audit of EnKK's integrated management system and during the OSART missions in Philippsburg NPP and Neckarwestheim NPP.
Survey of Zinc Injection Experience at Siemens PWR's: Differences and Common Characteristics
Hans Walter Rich, Bernhard Stellwag, Fred Böttcher, Micael Jürgensen, Günter Holz, Bernd Markgraf, Sigrid Schütz and Milton Rübenich
Zinc injection for reduction of radiation fields at Siemens PWRs covers eight plants and time periods up to 13 years. This paper gives an overview of the influence of zinc injection on the dose rates of the plants and on their coolant properties. The change of the concentration of corrosion and activation products in the coolant after zinc injection start is examined and evaluated with regard to common characteristics and differences. Coolant chemistry changes are evaluated also with regard to dose rate decrease rates and the total dose rate reduction effect measured at the plants. The evaluation shows that the change of coolant properties and dose rates are plant-specific and dependent on the mode of operation.
Long-term Test of Online Measuring Concentration of Borate in the Stand-by Liquid Control System of Isar 1 NPP
Bernhard Schnurr, Harry Neder and Christian Scheuerer
In BWR plants a boron injection system, called stand-by liquid control system, is installed if the sub-critical state is not reached with adequate certainty by inserting the control blades. This system has a storage tank which contains a certain amount of boron as sodium pentaborate. While the volume may be monitored by observing the fill level in the tank, there is no similar simple procedure to continuously survey the concentration with sufficient sensitivity. The procedure presented is aiming at identifying a method which also enables continuous monitoring of the concentration with appropriate accuracy.
Iron Measurement in Comparison: ICP MS, AAS and UV Visible Spectrometry
Birgit Felgenhauer, Rolf Schorle, Andreas Speck and Hermann Wacker
Iron measurements are regularly carried out for the chemical operational surveillance of the circuits of boiling water reactors and pressurised water reactors. Within the last few years the detection limits could be reduced steadily by using modern techniques like ICP-MS and AAS. This paper contains a comparison of measurement results which were obtained with classical and modern techniques in the reactor water of the boiling water reactor Philippsburg 1 (KKP 1) and in the feedwater of the pressurised water reactor Philippsburg 2 (KKP 2).
Raising Poer Reserves by Lowering Measuring Uncertainties
Swen Arens and Jörg Holtmann
The operation of a power plant close to maximum capacity is limited by the uncertainty of the measuring instruments used, resulting in a safety margin that must not be exceeded. For example, safety margin in a nuclear power plant is up to 2 %. By using suitable flow-measuring technology with a lower overall uncertainty, safety margin can be narrowed and thus the thermal output of the power plant can be increased.
Final Stage of First Super-critical 460 MW CFB Boiler Construction - First Experience in Lagisza
Waldemar Ostrowski and Damian Goral
Steam boilers with circulating fluidised bed combustion have been advanced in the past years and proved well as large-scale technology. A further step was the development and construction of a boiler with super-critical steam parameters and increased output. In 2002 the Polish utility Południowy Koncern Energetyczny SA awarded a contract to Foster Wheeler Energia Oy to erect a fluidised bed boiler for the Lagisza power plant. Construction of the 460 MW plant was started in 2006. The plant has been in commercial operation since 2009.
New Ash Conveyors in the Largest Lignite-fired Unit in Niederaußem
Mario Dikty and Dirk-Michael Weber
In 2002 the Niederaußem power plant was extended by a BoA unit with a gross capacity of 1000 kW. During operation, problems occurred with ash discharge from the pressure vessels and transport to the ash silos. Tests with the FLUIDCON® process demonstrated that this system meets all requirements and can react flexibly on uneven distribution of the accumulating ash quantities transversely to the flue gas direction. In the meantime the complete ash removal system of unit K was modified accordingly.
Noise from Steam Valves in Power Plants - Calculation and Practice
Taking steam conditioning valves as an example, which are of particular importance from an acoustics point-of-view, this paper explains possible reasons for problems when noise limits aimed for in the planning phase are exceeded in practice. A measuring system using laser vibrometry is presented. With the aid of this system it is possible to carry out non-contact measurements of the vibrations of hot steam pipes. The results of such measurements can be used both as a proof of the achievement of guarantee values and as a basis for remedial actions with respect to airborne sound and vibrations.