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dc.contributor.advisorMichael P. Short and Lin-wen Hu.en_US
dc.contributor.authorDumnernchanvanit, Ittinopen_US
dc.contributor.otherMassachusetts Institute of Technology. Department of Nuclear Science and Engineering.en_US
dc.date.accessioned2018-04-27T17:54:59Z
dc.date.available2018-04-27T17:54:59Z
dc.date.copyright2017en_US
dc.date.issued2017en_US
dc.identifier.urihttp://hdl.handle.net/1721.1/115003
dc.descriptionThesis: Ph. D., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2017.en_US
dc.descriptionThis electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.en_US
dc.descriptionCataloged from student-submitted PDF version of thesis.en_US
dc.descriptionIncludes bibliographical references (pages 448-467).en_US
dc.description.abstractThe nuclear industry is no exception when it comes to those affected by fouling deposit problems. Fouling deposits on fuel rods in nuclear reactors, known as crud, can cause a variety of undesirable effects including axial power shifts, accelerated corrosion, increased primary circuit radiation dose, and possible fuel failure. This study revisits the crud problem once again using a newly constructed Internally Heated Testloop For PWRs (IHTFP) and new analytical techniques, and attempt to find a way to prevent or mitigate crud, or at least better understand it. This is the first time that fuelrod coatings are examined as a way of countering crud growth. These coatings are chosen based on their surface chemical properties and robustness at PWR conditions. For the goal of gaining a better understanding of crud, this study is the first to apply fractal analysis to characterize crud. To achieve both of these goals, the IHTFP was built to obtain crud grown under the PWR thermal-hydraulic and chemical conditions. The crud-resistant coatings experiments show significantly reduced crud surface coverage, indicating reduced crud adhesion, for TiC and ZrN coatings. The results roughly agree with London-van der Waals theoretical force predictions, suggesting that London-VDW forces are responsible for the adhesion of crud to fuel cladding. This knowledge can be useful in designing better crud-resistant materials. The fractal analysis can provide a simple, effective way to characterize the macro-scale behavior of crud with its micro-scale properties. The fractal analysis experimental study found R2 values to be very close to one when applying the box-counting method to crud, which is one piece of evidence to support the usage of fractal analysis on crud. Moreover, a strong logarithmic relationship trend between fractal dimension and porosity was found. This relationship applies to both the IHTFP's and Westinghouse loop's crud, even though the two experimental setups used different crud precursors and heat flux. This could indicate that crud's fractal dimension is dependent only on porosity. This relationship could simplify crud modeling and lead to better predictions of crud's behaviors. Better predictions can lower margins, leading to more efficient reactors.en_US
dc.description.statementofresponsibilityby Ittinop Dumnernchanvanit.en_US
dc.format.extent467 pagesen_US
dc.language.isoengen_US
dc.publisherMassachusetts Institute of Technologyen_US
dc.rightsMIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.en_US
dc.rights.urihttp://dspace.mit.edu/handle/1721.1/7582en_US
dc.subjectNuclear Science and Engineering.en_US
dc.titleCharacterization and mitigation of crud at pressurized water reactor conditionsen_US
dc.title.alternativeCharacterization and mitigation of crud at PWR conditionsen_US
dc.typeThesisen_US
dc.description.degreePh. D.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Nuclear Science and Engineering
dc.identifier.oclc1031706854en_US


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