Reactor Surveillance and Diagnostics

Workshop on Core Monitoring for Commercial Reactors: Improvements in Systems and Methods

The workshop on Core Monitoring for Commercial Reactors: Improvements in Systems and Methods (CoMoCoRe'99) was organised jointly by Vattenfall AB, ABB Atom and the Swedish Nuclear Power Inspectorate and was held on 4-5 October 1999 in Stockholm. It was chaired by T. Lefvert. The main objective was to discuss how instrumentation, methods and models used in core monitoring (CM) could be validated, or, if needed, improved and further developed to provide more reliable and/or detailed information on local power in the core and on other parameters indirectly affecting fuel duty as e.g. the core decay ratio in a BWR. Another important objective was to show how the core monitoring system can be used to support reactor operation in normal and anticipated transient modes and to supply data used to derive initial key core parameters for transient- and accident analysis. It dealt with applications for all commercial LWR types, including VVER.

The workshop was attended by about sixty participants from 30 organisations representing 15 countries. Twenty-three papers were presented in four technical sessions. The technical sessions included:

  • requirements on core monitoring systems, sensors;
  • signal processing and evaluation;
  • improved core models in core monitoring;
  • improved core monitoring systems;
  • design and operating experience.
Major trends observed include:
  • introduction of more detailed physics models in on-line calculations for both BWR and PWR;
  • more wide-spread discussion on possible advantages of backfitting some PWR types with fixed in-core detectors;
  • methods to combine the information from on-line measurements and on-line calculations.
Some conclusions:
  • There is an on-going development in physics models in the reactor physics, thermal-hydraulics and other related research communities. This will provide improved models that can be implemented in CM systems.
  • Signal validation is of prime importance in any CM system and could be a subject for further study in the framework of NEA.

More rigorous methods to combine information from measured and calculated data should also be very useful in future CM systems.

Previous meetings in this area

In core Instrumentation and Reactor Core Assessment

  • Specialist Meeting on In-core Instrumentation and Reactor Core Assessment (Mito, 1996)
  • Specialist Meeting on In-core Instrumentation and Reactor Core Assessment (Pittsburg, 1991)  (pdf 14.9 mb)
  • Specialist Meeting on In-core Instrumentation and Reactor Core Assessment (Cadarache, 1988)  (pdf 17.0 mb)
  • Specialist Meeting on In-core Instrumentation and Reactor Core Assessment (Fredrikstad, 1983)   (pdf 15.8 mb)


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