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Kord Smith and Kaichao Sun. Hauptman, Sara(Sara E.) Massachusetts Institute of Technology. Department of Nuclear Science and Engineering. Massachusetts Institute of Technology. Department of Nuclear Science and Engineering 2020-01-08T19:34:47Z 2020-01-08T19:34:47Z 2019 2019 https://hdl.handle.net/1721.1/123366 1134770388 This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. Thesis: S.B., Massachusetts Institute of Technology, Department of Nuclear Science and Engineering, 2019 Cataloged from student-submitted PDF version of thesis. Includes bibliographical references (pages 49-50). Subcritical graphite piles were originally built as an important tool for determining diffusion length and criticality in the early days of nuclear engineering. MIT still retains a graphite exponential pile, recently recommissioned back into service, and utilized by students for hands-on demonstration of classroom topics like buckling, subcritical multiplication, and 1 group diffusion. For most effective use, the characteristics of the pile, including flux profile, source-dependence, and fuel slug composition, should be well known. In this thesis neutron radiography was performed on 10 different fuel slugs from the pile to directly measure the thickness of the aluminum cladding and confirm the suspected method of slug fabrication. This sample of fuel slugs had an average clad thickness of 4.66mm±0.03mm on the bottom, 4.10mm±0.02mm on the top, and 1.48mm±0.02mm on the side. Additionally, a detailed neutronic model of the pile was created using MCNP5 software and used to map the spatial source dependence. Experimental measurements were taken to compare to simulated model data and determine the accuracy of the model. The overall flux shapes were similar, but the error between the model prediction and the measured data was greater than 15% for the 6-7 sampling locations that were furthest from the source. The characterization of the slugs and development of a neutronic model will allow for more localized calculations of a wide variety of fuel loading patterns and better utilization of the Pile as a teaching tool.. by Sara Hauptman. S.B. S.B. Massachusetts Institute of Technology, Department of Nuclear Science and Engineering 60 pages eng Massachusetts Institute of Technology MIT 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. http://dspace.mit.edu/handle/1721.1/7582 Nuclear Science and Engineering. Characterization of the MIT Graphite Exponential Pile Thesis application/pdf 2020-01-08T19:34:44Z Publication Bachelor NucEng unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="a73bb1f9-396c-4aba-ba7b-958d5c041b65"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>Characterization of the MIT Graphite Exponential Pile</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2019</PublicationDate> <Authors> <Author> <DisplayName>Hauptman, Sara(Sara E.)</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Nuclear Science and Engineering.</Keyword> <Abstract>Subcritical graphite piles were originally built as an important tool for determining diffusion length and criticality in the early days of nuclear engineering. MIT still retains a graphite exponential pile, recently recommissioned back into service, and utilized by students for hands-on demonstration of classroom topics like buckling, subcritical multiplication, and 1 group diffusion. For most effective use, the characteristics of the pile, including flux profile, source-dependence, and fuel slug composition, should be well known. In this thesis neutron radiography was performed on 10 different fuel slugs from the pile to directly measure the thickness of the aluminum cladding and confirm the suspected method of slug fabrication. This sample of fuel slugs had an average clad thickness of 4.66mm±0.03mm on the bottom, 4.10mm±0.02mm on the top, and 1.48mm±0.02mm on the side. Additionally, a detailed neutronic model of the pile was created using MCNP5 software and used to map the spatial source dependence. Experimental measurements were taken to compare to simulated model data and determine the accuracy of the model. The overall flux shapes were similar, but the error between the model prediction and the measured data was greater than 15% for the 6-7 sampling locations that were furthest from the source. The characterization of the slugs and development of a neutronic model will allow for more localized calculations of a wide variety of fuel loading patterns and better utilization of the Pile as a teaching tool..</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>