Engineering Commons^™

Investigation Of Zircaloy-4 Doped With Metallic Burnable Poisons, Chrysostomes K. Kahambwe

Masters Theses

Burnable poisons are used in all commercial reactors to level the power distribution and to reduce the requirements for an excessively large control system. It has been proposed that metallic rare earth elements, serving as burnable poisons, might be alloyed with the fuel cladding rather than mixed with fuel in the form of compounds. This research project studies the effect of such additions on the ductility.and the corrosion resistance of three such alloys.

Alloys of Zircaloy-4 with 0.5 % Gd, 2.0 % Dy, and 2.0 % Er, chosen to represent the maximum likely concentrations of the absorbing elements to be …

Dose Analysis By Radiation Treatment Planning System (Tps) Software Vs. Thermoluminescent Dosimeters Output, Carlos Eugene Corredor

Masters Theses

Solid tumors are often treated with external beams of photons generated by bremsstrahlung radiation. These beams are shaped and filtered to optimize dose to specific regions defined by the treatment plans, which may involve irradiations from multiple angles. It is important that doses to healthy tissue not exceed tolerance doses and that the dose to the tumor be maximized. To accomplish these objectives, commercially available three-dimensional treatment planning software (TPS) is used to calculate doses to healthy tissue and to the tumor. It is generally believed that these commercial software packages calculate doses to the patient to within a few …

Fault Detection And Isolation Expert System And Kernel Smoothing Techniques To Monitor The Continuous Automated Vault Inventory System (Cavis), Joseph Michael Bowling

Masters Theses

The Continuous Automated Vault Inventory System (CAVIS™) is a system designed to continually monitor the status of special nuclear materials (SNM) at the Oak Ridge based Y-12 facility. CAVIS consists of an integrated package of low-cost sensors used to continuously monitor weight and radiation attributes of the stored items. The CAVIS system detects “change-in-state” of the special nuclear material and generates an appropriate alarm. Unfortunately, the CAVIS system is susceptible to false alarms that do not coincide with the removal of special nuclear material. These false alarms may be due to the random stochastic nature of the measurements, due to …

The Sequential Probability Ratio Test (Sprt) In Feature Extraction And Expert Systems In Nuclear Material Management, Thomas Jay Harrison

Masters Theses

The Y-12 National Security Complex in Oak Ridge, TN, maintains the nation’s stockpile of highly enriched uranium (HEU) for use in nuclear weapons. A proposed system for monitoring the HEU is the Continuous Automated Vault Inventory System (CAVIS), which uses radiation and mass detectors. Radionuclides decay stochastically (in a random matter that can be approximated by statistical analysis) and normal electronics and compute failures are inevitable. Therefore the system can and does experience spurious alarms arising from normal decay characteristics and system operation and not from material removal.

To reduce the spurious alarms and their associated costs, CAVIS operators desire …

Data-Based Modeling Methods For Fault Detection And Isolation In Heat Exchangers, Aaron Patrick Sawyer

Masters Theses

A multivariate analysis method is developed for processing measurements, and for detecting and isolating faults and monitoring performance degradation in heat exchanger control loops. A heat exchanger in a typical temperature-to-flow cascade loop s considered. A mechanistic thermal-fluid model for the components in the system is developed and compared to an installed laboratory heat exchanger control loop. A supplemental model for condenser hear transfer is included. The mechanistic model generate data to develop a data driven model using the Group Method of Data Handling (GMDH) approach. The GMDH model matches the mechanistic model well.

A Fault Detection and Isolation (FDI) …

Transportable Modular Balance Of Plant Study For Small Nuclear Power Plants, Martin Rodney Williamson

Masters Theses

The purpose of this research is to develop a conceptual design for a balance of plant (BOP) layout to coordinate with small nuclear power plants and to demonstrate the feasibility of transporting this BOP via US waterways. The Westinghouse International Reactor, Innovative and Secure (IRIS) is used as the primary plant for the base-case study. IRIS is an advanced design pressurized water reactor (PWR) with a power rating of 1000MWt (approximately 335 MWe). A Matlab® script file, named BOSCO, automates the process of calculating the BOP component sizes for different initial conditions, enabling the use of different primary systems and/or …

A Study Of Thermal Creep In The Vanadium Alloy, V-4cr-4ti, In A Lithium Environment, Scott Emmett O'Rourke

Masters Theses

Vanadium alloys have been proposed as structural materials for fusion reactors. Although favorable high-temperature properties and low neutron activation encourage its use, it must be used with a coolant that does not allow the addition of interstitial, embrittling impurities to the alloy. Liquid lithium is the only acceptable coolant known at the present time. Unlike behavior with other candidate coolants, the oxygen level in vanadium alloys decrease with time in the presence of lithium.

In order to evaluate the thermal creep of this alloy in the presence of lithium, a set of internally pressurized tube specimens is being exposed to …