Masters Theses

Keywords and Phrases

Americium-241; Americium-242; Bateman equation; BEGe 3825; MCNP; Plutonium age


“Am241 is typically produced via Pu241 decay in a uranium fueled reactor. Presence of Am241 can be used as the age estimation tool for spent fuel, which is a focus of this thesis along with the interest of the measurement and the ratio of production rates of Am241’s activation products; Americium-242 and its first excited state of Americium-242m. MCNP models of the core and BEGe 3825 detector were built. These models were compared with established and physical measurements of gamma/x-ray standards that were available at the reactor. Thermal fluxes at 200 kW for potential foils centered in the source holder tube were within a factor of 1.5 when compared to existing known MSTR thermal flux values. Unmodified simulated BEGe 3825 detector full energy peak efficiency values were well within a factor of 2 for both the Mixed and Europium source validation. Am241 build-up in Plutonium can be predicted to be measured to great certainty, using the BEGe 3825 that is available at the reactor by analyzing 59.50 keV using Prospect with estimated net uncertainty of 0.796% and 5.841%, for reactor grade and weapons fuel after 1 year of storage using the corrected BEGe 3825 simulation. Uncertainty values decreased as further time passed. Simulation considered full photon spectrum. Time estimate range values for modified WG plutonium differed by +1.11% and -0.895% error during the specific modified count time 19 year decay case. Study into Am242 and Am242m production revealed that the combined 102.616 keV displays a very reliable simulated Prospect net cps uncertainty around 1-2% free of Am241 photopeaks at irradiation times greater than 30 minutes for both the exempt and non-exempt quantities of Am241 used as standard sources”--Abstract, page iii.


Usman, Shoaib

Committee Member(s)

Liu, Xin (Mining & Nuclear Engr)
Alajo, Ayodeji Babatunde


Nuclear Engineering and Radiation Science

Degree Name

M.S. in Nuclear Engineering


Missouri University of Science and Technology

Publication Date

Spring 2017


xii, 238 pages

Note about bibliography

Includes bibliographic references (pages 236-237).


© 2017 Eric Anthony Feissle, All rights reserved.

Document Type

Thesis - Open Access

File Type




Thesis Number

T 12077