The Korea Hydro and Nuclear Power has built a new modular type of dry storage facility, known as MACSTOR KN-400 at Wolsong reactor site. The building has the capacity to store up to 24000 CANDU spent fuel bundles in a 4 rows by 10 columns arrangement of silos. The MACSTOR KN-400 consists of 40 silos; each silo has 10 storage baskets, each of which can store 60 CANDU spent fuel bundles. The development of an effective method for spent fuel verification at the MACSTOR KN-400 storage facility is necessary in order for the International Atomic Energy Agency (IAEA) to meet with safeguards regulations. The IAEA is interested in having a new effective method of re-verification of the nuclear material in the MACSTOR KN-400 dry storage facility in the event of any loss of continuity of knowledge, which occasionally happens when the installed seals fail. In the thesis work, MCNP models of central and corner structures of the MACSTOR KN-400 facility are developed, since both have different types of re-verification system. Both gamma and neutron simulations were carried out using the MCNP models developed for MACSTOR KN-400. The CANDU spent fuel bundle with discharge burnup of 7.5 GWD/t (burned at specific power of 28.39 MW/t) and 10 years cooled was considered for radiation source term estimation. For both the structures, MCNP simulations of gamma transport were done by including Cadmium-Zinc-Telluride (CZT) detector inside the re-verification tube. Gamma analyses for different spent fuel bundle diversion scenarios were carried out. It was observed that for diversion scenarios wherein the bundles are removed from the inner portions of the basket (opposite side of the collimator of the re-verification tube), it was difficult to conclude whether diversion has taken place based on the change in gamma radiation signals. Similar MCNP simulations of neutron transport were carried out by integrating helium-3 detector inside the re-verification tube and the results obtained for various diversion scenarios were encouraging and can be used to detect some spent fuel diversion cases. In the central structure, it was observed that addition of moderating material between the spent fuel and the detector increased the sensitivity of the detecting system for various diversion cases for neutron simulations. In the worst scenario, the diverting state could divert 14 spent fuel bundles from each of 10 baskets in a silo from the basket region opposite to the collimator of the re-verification tube. The non-detection probability for this scenario is close to 1. This diversion cannot be easily detected using the currently designed detection system. In order to increase the detection probability, either the design of the facility must be changed or other safeguard methods, such as containment and surveillance methods must be used for safeguarding the nuclear material at the facility.

Millisecond pulsars (MSP) are old neutron stars that have been spun up to high spin frequencies(as fast as 716 Hz) through the accretion of matter from a companion star. The extreme stellar densities in the core of globular clusters creates numerous accreting neutron star systems through exchange interactions; this leads to the formation of MSPs in larger numbers than in the galactic disk. Over the course of this project, we have collected over 17 TB of data on the 3 globular clusters M28, NGC6440 and NGC6441 plus 2 observations on NGC6522 and NGC6624 as part of the recently begun S-band survey using the Green Bank telescope. I have analyzed and conducted acceleration searches on 70% of the data and discovered 7 of the 23 new millisecond pulsars reported in this work. One year of timing observations of the pulsars in M28 and NGC6440 has led to the phase connected solution for 12 of the 15 new pulsars in those two clusters, 7 of which are in binaries. We have measured the rate of advance of periastron for two highly eccentric binaries and assuming this is purely due to general relativity, this leads to total system masses of (1.616 - 0.014)M and (2.2 - 0.8)M for M28C and NGC6440B respectively. The small mass function combined with this information imply that the most likely neutron star mass of NGC6440B is either very large or else there could be significant contribution to the advance of periastron from a nonzero quadrupole moment due to tidal interaction with the companion. Measurements of the period derivatives for many of the pulsars show that they are dominated by the dynamical effect of the gravitational field of the clusters. Finally, we have discovered the potential presence of a Mars-mass planet orbiting the pulsar NGC6440C with a period of 21 days. A dedicated timing campaign will be necessary to confirm the presence of such an object.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of North Texas, Dec., 2007. / Title from title page display. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Th. phys. EPFL Lausanne, 1983.

Thesis (M.S.)--University of Michigan, 1957. / Included in back pocket: Physics analysis of the subcritical reactor Model 9000/ by Poh-shien Young.

Thesis (M.S.)--Tsing Hua University, 1960. / Research done at the University of Michigan.

Thesis (M.S.)--Missouri University of Science and Technology, 2010. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed April 7, 2010) Includes bibliographical references (p. 41-42).

Thesis (M. Phil.)--University of Hong Kong, 1993.