Doctoral Dissertations

Keywords and Phrases

Burn-up calculations; Detector dead-time calculations; MOX fuel investigation; Online burn-up analysis; Pu/U discrimination


“This dissertation consists of three main parts. The first part is devoted to the comprehensive dead-time calculations with different detectors and conditions using different dead-time models as well as computer simulations. The minimum time that must separate two detectable events is called the counting system’s dead-time. If events take place during the system’s dead-time, they will not be recorded and will be lost. Such lost information is very important in many applications including high-intensity spectroscopy and nuclear spent fuel interrogations. The second part, a multitude of fission products identified as candidates have been scrutinized for their suitability of burnup analysis and spent fuel analysis for irradiated Mixed Oxide (MOX) fuels. Best isotopes obtained for analysis by investigating half-life, photon energy, fission yield, branching ratios, production modes, thermal neutron absorption cross section and fuel matrix diffusivity. 132I and 97Nb are identified as good isotope candidates for MOX fuel on-line burnup analysis. The third and most important part, in terms of time spent and effort, deals with spent fuel analysis using non-destructive (NDA) delayed fast neutron measurement technique for safeguard purposes. The spent fuel investigation experiment was held in Missouri University of Science and Technology Research Reactor (MSTR) which is a swimming pool type reactor and licensed to operate at 200 kilowatts power. The core of the reactor consists of 15 fuel elements with low-enriched Uranium-235. Using the NDA technique, the reactor fuel burnup and 235U - 239Pu conversion values calculated. The fast neutron measurements were taken with a liquid scintillator detector which its dead-time value calculated to be 101.2 μs for paralyzing dead-time model and 254.8 μs for non-paralyzing model”--Abstract, page iv.


Usman, Shoaib
Liu, Xin (Mining & Nuclear Engr)

Committee Member(s)

Lee, Hyoung-Koo
Alajo, Ayodeji Babatunde
Smith, Joseph D.


Nuclear Engineering and Radiation Science

Degree Name

Ph. D. in Nuclear Engineering


Missouri University of Science and Technology

Publication Date

Spring 2015

Journal article titles appearing in thesis/dissertation

  • GM Counter Dead-time Dependence on Applied Voltage, Operating Temperature and Fatigue
  • A Comparison of Traditional and Hybrid Radiation Detector Dead-time Models and Detector Behavior
  • Portable Spectroscopic Fast Neutron Probe and 3He Detector Dead-time Measurements
  • Characterization of Best Candidate Isotopes for Burnup Analysis and Monitoring of Irradiated Fuel
  • Spent Fuel Interrogation Using Delayed Fast Neutron Spectrum at Missouri University of Science and Technology Reactor


xiv, 167 pages

Note about bibliography

Includes bibliographic references.


© 2015 Tayfun Akyurek, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Thesis Number

T 11993

Electronic OCLC #