Detection systems used to monitor reactor operations are of significant interest as tools for verification of operator declarations. Current reactor site safeguards are limited to visual inspections and intrusive monitoring systems. The recent development of antineutrino detectors may soon allow real-time monitoring from an unobtrusive location. Antineutrinos are produced through beta decay of fission products in the core. The lack of charge and small mass of the antineutrino ensures an extremely low interaction probability with all matter, effectively making the particle impossible to shield. As the fuel isotopic composition changes with burn-up, the primary fission source changes from ²³⁵U to ²³⁹Pu. Since differing antineutrino energy spectra are produced by each fissionable isotope, the antineutrino flux will also change as a function of burn-up. Supported by reactor simulations from nuclear codes, antineutrino detectors may provide a window into the reactor core and provide inspectors with tools to verify legitimate operations.
This thesis is focused on the antineutrino rate produced by CANadian Deuterium Uranium reactors (CANDU) during startup. A CANDU fuel bundle model was created with the TRITON module from the SCALE6.1 code to calculate isotopic antineutrino rates for a single bundle. A full core CANDU model that incorporates refueling was also created for the first 155 days of operation after startup by using a Python 2.6 script to handle pre- and post-calculations. All simulations were calculated using operational data from Point Lepreau Generating Station produced by proprietary codes for the forthcoming fresh core startup.
Dependence of the antineutrino rate on power and bundle replacement was analyzed, with a ±10% change in power causing a ±10% change in antineutrino rate, and the CANDU detector effectively measuring a 10% decrease in power within 9 hours of collection time. Bundle refueling was shown to only slightly modify the antineutrino rate, requiring a target volume more than 20 times larger than the present detector to effectively identify the change due to the bundles refueled over a one week period. Diversion of 15% or more of the total amount of bundles can be effectively measured by the CANDU detector within a one month counting period.