Halden Reactor Research Articles

Tools for the Standardised Software Safety Assessment. (The SOSAT Project)

The possibility of using tools for assistance in software safety assessment is of importance for all safety related applications of computers, particularly in the nuclear field. A set of such tools has therefore been developed within the framework of the SOSAT (Software SAfety Tools) project. The analysis starts on the basis of a memory dump of the processor, by extracting the program and translating it into a common assembly language (CAL). Translators from a variety of processors into CAL have been developed. CAL forms the basis for an analysis by a static analyser, and is also made executable and instrumented for dynamic testing. Applications of the tools on test examples show that the use of these tools leads to a deeper and more cost effective analysis of safety related programs.The SOSAT project is a joint project between TüV Norddeutschland in Hamburg, GRS in Garching, and the OECD Halden Reactor Project in Norway. It has been sponsored by Bundesministerium für Forschung und Technologie in Germany.

Irradiation Studies of JAERI's Fuel at Halden Reactor

Irradiation Studies of JAERI's Fuel at Halden Reactor

Irradiation studies of JAERI's fuel at Halden Reactor.

Japan Atomic Energy Research Institute (JAERI) has conducted irradiation experiments utilizing extensive fuel instrumentations at HBWR in Norway since 1967. The major effort has been given to the study of pellet cladding interaction. A special emphasis was placed on the studies of inpile fuel rod deformation including cladding diameter measurements. The experimental conditions cover steady state irradiation, power ramping and power cycling. The data obtained from the experiments were used for development and verification of the computer code FEMAXI. The present paper reviews and summarizes the major results of the experiments.

The Large-Scale Research Simulator NORS for Man-Machine Systems Development

The use of real-time simulotors for control system development is a well established application area. With the growing number of large-scale training simulators their use for other purposes than training such as human factors studies and control room improvements is becoming a common practice. For the development and evaluation of highly sophisticated operator support systems the use of large-scale plant simuI a tors as test facilities is becoming a practical necessity. These development trends are leading to the introduction of a new type of real-time simulators. the dedicated large-scale research simulators.The NORS (NOkia Research Simulator) is of this new type. It was implemented during 1983 Halden Reactor Project's Man-Machine Systems Laboratory (HAMMLAB). The HAMM-LAB research programme on advanced computer and colour display based control rooms covers the establishment of experimental techniques and methods for the new facility basic Man-Machine Systems research with development of concepts and theories experiments on information presentation and exercise of control and experimental validation of advanced computerized operator support systems.The NORS simulator was designed to effectively support the needs of the versatile research programme. The design goal was to combine the simulation scope and quality of large-scale training simulators with a flexible software and hardware structure readily adaptable to various experimental conditions. Novel features of the simulator software include extensive use of computer aided modelling and generic modelling packages for simulation of plant systems and instrumentation, highly modular structure and comprehensive use of a data base and software development system.

Nuclear Engineering for an Uncertain Future

"Nuclear Engineering for an Uncertain Future." Nuclear Technology, 62(1), p. 124 Additional informationNotes on contributorsJohn M. ChristensonJohn M. Christenson has been a faculty member in the Department of Chemical and Nuclear Engineering at the University of Cincinnati since 1970. In 1973 he was an ASEE-Ford Foundation industrial resident with Northern States Power at the Prairie Island Nuclear Generating Plant. On academic leave in 1979, he was a member of the Reactor Safety and Control Division of the Halden Reactor Project. He has served as a consultant for several national laboratories and nuclear utilities. His current interests are in the areas of applied reactor analysis, the determination of reactor operability rules, and the medical applications of nuclear technology.

An Investigation of Methods for Production and Verification of Highly Reliable Software

A joint project between Technical Research Centre of Finland and OFXD Halden Reactor Project with the aim of investigating methods for developing and testing computer programmes with high requirements for reliability has been completed. This paper gives a short outline of the project. The main emphasis is on the experiences gained during the project and on the conclusions and recommendations made on the basis of this experience. Methods used for the specification, programming, programme analysis, testing, and reliability assessment are discussed together with their virtues and weaknesses.

Spectral Analysis of Sampled Nuclear Reactor Plant Data with Heterodyne Digital Filtering Techniques

A design procedure for the digital algorithm of a heterodyne power spectral density analyzer using digital components has been developed. The heterodyne filtering, a straightforward technique to yield directly the spectral densities, avoids a number of the disadvantages inherent in the method of determining spectral densities of stochastic signals using the Fourier transform of precalculated correlation functions.For the design of the required digital low-pass filters in this system, the method of bilinear conformal transformation of the continuous s domain onto the discrete z domain has been used to generate recursive filter difference equations.The complete digital analyzer, consisting of a group of digital filters with contiguous passbands, has been implemented on a process computer and tested with real plant data at the OECD Halden Reactor.

ハルデン・プロジェクトの活動と成果

ハルデン・プロジェクトの活動と成果

Studies of Fuel-Clad Mechanical Interaction and the Resulting Interaction Failure Mechanism

Fuel performance studies at the Halden reactor have given valuable information on how various design parameters affect the mechanical interaction between fuel and cladding. The experiments have als...

Computer Control of the Halden Boiling Water Reactor Part II: Reactor Plant and Core Control

At the OECD Halden Reactor Project advanced control methods have been applied for on-line control of the main plant variables and of the power distribution in the reactor core.For the control of the plant variables, which comprise the integral nuclear power and the reactor vessel pressure, a control algorithm was developed which is based on a linear, time-invariant model of the reactor and its heat removal circuits. The algorithm is optimized with respect to a quadratic performance index. Kalman filtering technique was used for the estimation of inaccessible state variables.The performance of the control system was tested in reactor experiments. Different perturbations were introduced to the reactor plant and the behaviour of the controlled process was observed. The results indicate that the chosen control method is promising with respect to applying it to nuclear power plants.As a parallel project, an on-line control procedure was developed for the spatial distribution of the power generation in the reactor core. The chosen method implies the continuous estimation of the present state of the process and of the state-dependent process parameters. From this information a feedback function is evaluated which converts the deviation between actual and desired distribution into a control rod pattern which yields an optimal approximation of the de sired power distribution.

Computer Control of the Halden Boiling Water Reactor Part I: Plant Supervision Function and Corresponding On-Line Software System

At the OECD Halden Reactor Project, Halden, Norway, an international research and development programme on computer control of nuclear power reactors is being conducted. The programme aims for demonstration of plant supervision functions, direct digital control using conventional and advanced methods, and schemes for optimal control of the core power distribution. These functions are implemented on IBM-1800 and NORD-l process control computers with about 750 analogue inputs and 200 digital inputs and outputs, disk and tape stations, displays and operator console. The multitude and complexity of computer functions have required the design of an extensive user-oriented software system to obtain efficient data flow and computer utilization, and to serve as basis for proper operator-process communication functions. The computer system has been ope rational for on-line applications since 1967 and in routine operation for supervision, data logging and direct digital control, whereas advanced control methods have been tried on the reactor in separate experiments.The present paper describes the plant supervision system comprising monitoring of plant variables, alarm handling and operators communication, and includes some of the operational experience obtained.

Case Study of Operator Communication and Planned Development in Connection with Computer Control of the Halden Boiling Water Reactor

Process computers are increasingly being used for control and supervision of nuclear power reactors as the reactor control become s more complex due to increased plant size and load requirements from the grid. In addition, the operating characteristics are such that one is getting closer to the technical limits of the system. As a consequence, the extended use of computers implies that more emphasis is put on operator-proces s communication.At the OECD Halden Reactor Project, the reactor being an experimental power reactor, an international research and development programme on computer control of nuclear power reactors is being conducted. The programme aims for demonstration and routine operation of plant supervision as well as direct digital control using conventional and advanced methods. For experiments and routine operation the operator communication system is one of the main components in the system. This computer based system is operating in parallel with and is supplementing a conventional control system.The control desk consists of a console, alphanumeric and graphic Cathode Ray Tube display units (CR Ts) journal and report typewriters and plotter. The function of the console is to enable the operators to display process variables, request status, enter constants, change limits, and start and stop control routines. The CR Ts are used for prewarnings and alarm handling, messages, trend and status display, etc.The functions are implemented on a process control computer with about 750 analogue inputs and 224 digital inputs and outputs, 11 analogue outputs, 3 disk drives, 2 tape stations, and a line printer. The computer system has been operational for online applications since the end of 1967, and the scope of computer applications together with the communication system have gradually been extended.The multitude and complexity of computer functions have required a design of an extensive user-developed software to obtain an efficient dataflow and to serve as basis for proper operator - process communication functions. In designing and programming the communication system, emphasis has been put on obtaining sufficiently short response time, clear language with respect to text formats, organization of output, etc. Some efforts have been made to apply human engineering with the purpose of avoiding operator maloperations.The control desk has been easily understood and accepted by the operators, but not all functions introduced were equally much appreciated.Based on this experience which has been followed up by ergonomic studies, further investigations on man - computer - process communication systems will be conducted. This is envisaged due to thedevelopment of new hardware, like advanced minicomputers, and extended use of colour displays. A general purpose communication system, based on modules which can be configurated for the particular purposes can now be realized. The communication system could possibly be adapted to any general process computer. The development of a standard operator communication language is proposed.The paper deals with the experience obtained and the further development plans.

The Halden (Norway) Reactor

The Halden (Norway) Reactor