Load-Case and -Combination Database

摘要

The loading database is part of the pipeline analysis and monitoring system that will be used for nuclear power plant pipingrnsystems and connected equipment at 2 Finnish nuclear power plants. These plants are situated in Olkiluoto and operatedrnby Teollisuuden Voima OY (TVO). For a start the system will be used for class 1 piping systems only, but later on it may bernextended to other systems where it is useful. The system will comprise a large set of process systems and components. Pipingrncomponents, geometry, materials and systems are defined in an associated pipeline database [1]. Like the pipeline database,rnalso the load-database will have a combined alphanumerical and graphical user-interface to show the user what the actualrnstate is and what changes are made. The database system runs on a PC using commercially available database software [3].rnThis paper outlines the contents of the loading database system, which is being developed by TVO and VTT to facilitaternthe condition monitoring, aging and thermal transient follow-up, load history bookkeeping, documentation for componentrnload specifications and related analyses for class 1 piping.rnBasic dimensioning and necessary checks are made according to design standards like the ASME Code. This code definesrnallowable stress/strain levels in applicable service limits and rules how to estimate the usage factor of the cyclic loads.rnNormally those standards are applied that were valid when designing the plant or component. When ordering new components,rnthey have to be compatible with the rules valid at that moment. This is the practice, at least in Finland. This means thatrnin one plant different acceptance systems may exist simultaneously. This makes it difficult to find the applicable load data atrna time.rnThe load database is designed to:rn1. Contain and document the actually valid design load specification for any component or system inclusive servicernlimitsrn2. Act, as far as possible, as an input database to perform stress, flexibility, fatigue and/or crack analyses for the pipingrncomponents or systems under considerationrn3. Monitor and document the annual cumulative thermal transient eventsrn4. Perform book-keeping of the load-cases and -combinations that are valid at a time and contain the connection betweenrnold and new datarn5. Give the structure for the result database where the significant results of analyses are stored.rnLoad-cases and -combinations are fully user configurable. In the present application either static or dynamic pressures,rntemperatures, weights, and forced displacements can be included as basic loads. These are included in the database or coupledrnas structured files in case of large data quantities. Presently, the database structure has been designed and is implemented.rnThe items 1, part of item 2 and item 3 of the above list are implemented and test runs have been made for a pipingrnsystem for at least part of the analysis types described under item 2. Most of the basic programming work will be finalizedrnwithin one year. During the presentation the present status of the databases and program modules will be described.