Journal article Open Access

# The COLIBRI experimental program in the CROCUS reactor: characterization of the fuel rods oscillator

Vincent Lamirand; Pavel Frajtag; Daniel Godat; Oskari Pakari; Adolfo Rais; Mathieu Hursin; Grégory Hursin; Carlo Fiorina; Andreas Pautz

### DataCite XML Export

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<identifier identifierType="DOI">10.5281/zenodo.3667453</identifier>
<creators>
<creator>
<creatorName>Vincent Lamirand</creatorName>
<affiliation>Ecole Polytechnique Fédérale de Lausanne (EPFL); Paul Scherrer Institut (PSI)</affiliation>
</creator>
<creator>
<creatorName>Pavel Frajtag</creatorName>
<affiliation>Ecole Polytechnique Fédérale de Lausanne (EPFL)</affiliation>
</creator>
<creator>
<creatorName>Daniel Godat</creatorName>
<affiliation>Ecole Polytechnique Fédérale de Lausanne (EPFL)</affiliation>
</creator>
<creator>
<creatorName>Oskari Pakari</creatorName>
<affiliation>Ecole Polytechnique Fédérale de Lausanne (EPFL)</affiliation>
</creator>
<creator>
<affiliation>Ecole Polytechnique Fédérale de Lausanne (EPFL)</affiliation>
</creator>
<creator>
<creatorName>Mathieu Hursin</creatorName>
<affiliation>Ecole Polytechnique Fédérale de Lausanne (EPFL); Paul Scherrer Institut (PSI)</affiliation>
</creator>
<creator>
<creatorName>Grégory Hursin</creatorName>
<affiliation>Paul Scherrer Institut (PSI)</affiliation>
</creator>
<creator>
<creatorName>Carlo Fiorina</creatorName>
<affiliation>Ecole Polytechnique Fédérale de Lausanne (EPFL)</affiliation>
</creator>
<creator>
<creatorName>Andreas Pautz</creatorName>
<affiliation>Ecole Polytechnique Fédérale de Lausanne (EPFL); Paul Scherrer Institut (PSI)</affiliation>
</creator>
</creators>
<titles>
<title>The COLIBRI experimental program in the CROCUS reactor: characterization of the fuel rods oscillator</title>
</titles>
<publisher>Zenodo</publisher>
<publicationYear>2020</publicationYear>
<subjects>
<subject>Core monitoring and diagnostics</subject>
<subject>noise analysis</subject>
<subject>fuel vibration</subject>
<subject>research reactor experiment</subject>
<subject>zero-power reactor</subject>
</subjects>
<dates>
<date dateType="Issued">2020-01-20</date>
</dates>
<language>en</language>
<resourceType resourceTypeGeneral="JournalArticle"/>
<alternateIdentifiers>
<alternateIdentifier alternateIdentifierType="url">https://zenodo.org/record/3667453</alternateIdentifier>
</alternateIdentifiers>
<relatedIdentifiers>
<relatedIdentifier relatedIdentifierType="DOI" relationType="IsVersionOf">10.5281/zenodo.3667452</relatedIdentifier>
</relatedIdentifiers>
<rightsList>
<rights rightsURI="info:eu-repo/semantics/openAccess">Open Access</rights>
</rightsList>
<descriptions>
<description descriptionType="Abstract">&lt;p&gt;The present article presents the mechanical characterization of the fuel rods oscillator developed for the purposes of the COLIBRI experimental program in CROCUS. COLIBRI aims at investigating the radiation noise related to fuel vibrations. The main motivation is the increased amplitudes in the neutron noise distributions recorded in ex- and in-core detectors that have been observed in recent years in Siemens pre-Konvoi type of pressurized water reactors. Several potential explanations have been put forward, but no definitive conclusions could yet be drawn. Among others, changes in fuel assembly or pin vibration patterns, due to recent modifications of assembly structural designs, were pointed out as a possible cause. Computational dynamic tools are currently developed within the Horizon 2020 European project CORTEX, to help with understanding the additional noise amplitude. The COLIBRI program is used for their validation. An in-core device was designed, tested, and licensed between 2015 and 2019 for fuel rods oscillation in CROCUS, in successive steps from out-of-pile tests with dummy fuel rods to critical in-core tests. The characterization of its mechanical behavior is presented, in air and in water, and as a function of the load, for safety and experimental purposes. The device allows simultaneously oscillating up to 18 fuel rods. The maximum oscillation amplitude is 5 mm, while the maximum allowed frequency is 2 Hz, i.e. in the frequency range in which the induced neutron flux fluctuations are most pronounced in nuclear power plants.&lt;/p&gt;</description>
</descriptions>
<fundingReferences>
<fundingReference>
<funderName>European Commission</funderName>
<funderIdentifier funderIdentifierType="Crossref Funder ID">10.13039/501100000780</funderIdentifier>
<awardNumber awardURI="info:eu-repo/grantAgreement/EC/H2020/754316/">754316</awardNumber>
<awardTitle>Core monitoring techniques and experimental validation and demonstration</awardTitle>
</fundingReference>
</fundingReferences>
</resource>

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