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dc.contributor.advisorLandsberger, Sheldon
dc.creatorChristian, Jose L. 1963-en
dc.date.accessioned2014-10-13T14:38:03Zen
dc.date.issued2010-12en
dc.date.submittedDecember 2010en
dc.identifier.urihttp://hdl.handle.net/2152/26496en
dc.descriptiontexten
dc.description.abstractFor several decades, the idea of flying and landing a less-than-man-rated nuclear reactor for planetary surface applications has been considered. This approach promises significant mass savings and therefore reduction in launch cost. To compensate for the lack of shielding, it has been suggested the use of in-situ materials for providing radiation protection. This would take the form of either raw dirt walls or processed soil materials into blocks or tile elements. As a first step in determining the suitability of this approach, it is necessary to understand the neutron activation characteristics of these soils. A simple assessment of these activation characteristics was conducted for both Martian and Lunar soils using ORIGEN2.2. An average composition for these soils was assumed. As a baseline material, commonly used NBS-03 concrete was compared against the soils. Preliminary results indicate that over 2.5 times more gamma-radiation production of these soils vs. concrete took place during the irradiation phase (a baseline of 2.4 x 1011 neutrons/sec-cm2 was assumed). This was due primarily to radiative capture on Na23 and Mn55 and subsequent decay of their activation products. This is does not necessarily disqualify these materials as potential shielding material since the -radiation output was only in the order of 4.2 x 108 photons/cm3-sec. Furthermore, these soils did not show any significant activity after shutdown of the neutron source (the reactor), since all activation products had very short half lives. Their performance in this area was comparable to that of NBS-03 concrete.en
dc.format.mimetypeapplication/pdfen
dc.subjectnuclear reactoren
dc.subjectplanetary surface compositionen
dc.subjectsoil compositionen
dc.subjectMarsen
dc.subjectLunaren
dc.subjectMoonen
dc.subjectradiation shieldingen
dc.subjectneutron activationen
dc.subjectregolithen
dc.subjectman-rateden
dc.subjectin-situ materialsen
dc.subjectraw soilen
dc.subjectradiation protectionen
dc.subjectORIGENen
dc.subjectNBS-03 concreteen
dc.subjectneutron irradiationen
dc.subjectdecayen
dc.subjectbuild-upen
dc.subjectgamma radiationen
dc.subjectradiative captureen
dc.subjectsodium-23en
dc.subjectNa-23en
dc.subjectMn-55en
dc.subjectmanganese-55en
dc.titleUse of raw Martian and Lunar soils for surface-based reactor shieldingen
dc.typeThesisen
dc.date.updated2014-10-13T14:38:04Zen
dc.description.departmentMechanical Engineeringen
thesis.degree.departmentMechanical Engineeringen
thesis.degree.disciplineMechanical Engineeringen
thesis.degree.grantorThe University of Texas at Austinen
thesis.degree.levelMastersen
thesis.degree.nameMaster of Science in Engineeringen


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