Development of refined MCNPX paret multi channel model for transient analysis in research reactors

Research output: Contribution to report/book/conference proceedingsIn-proceedings paper


Reactivity insertion transients are in general analyzed (RELAP, PARET) using a two channel model, representing the hot assembly with specifi ed power distribution and an average assembly representing the remainder of the core . For the analysis of protected by the reactor safety system transients this approximation proves to give adequate results. Howeve r a more refined multi channel model representing the various assemblies, coupled through the reactivity feedback effects to the whole reactor core is needed for the analysis of unprotected transients with excluded over power and period trips. In the present paper a detailed multi channel PARET model has been developed which describes the reactor core in different clusters representing typical BR2 fuel assemblies . The distribution of power and reactivity feedback in each cluster of the reactor core is obt ained from a best estimate MCNPX calculation using the whole core geometry model of the BR2 reactor. The sensitivity of the reactor response to power, temperature and energy distributions is studied for protected and unprotected reactivity insertion tran sients, with z e r o a n d n o n z e r o reactivity feedback coefficients. The detailed multi channel model is compared vs. simplified few er channel models. The sensitivities of transient characteristics derived from the different models are tested on a few reactivi


Original languageEnglish
Title of host publicationPHYSOR 2012: Conference on Advances in Reactor Physics
Subtitle of host publicationLinking Research, Industry, and Education
PublisherANS - American Nuclear Society
Number of pages13
ISBN (Print)978-0-89448-085-9
Publication statusPublished - 15 Apr 2012
Event2012 - PHYSOR: Advances in Reactor Physics - Knoxville Convention Center, Knoxville, United States
Duration: 15 Apr 201220 Apr 2012

Publication series



Conference2012 - PHYSOR
CountryUnited States
Internet address


  • MCNPX, PARET, Multi channel model, Reactivity feedback, Reactivity insertion

ID: 6814438