PhD investigating Nuclear Data for the safe and efficient use and handling of next generation Nuclear Reactor fuel

In a world with growing energy requirements and a progression away from the traditional energy production using coal and Gas (~63% global energy production; see figure 1), more electricity production is needed using nuclear and renewable energy sources.

The focus of this PhD is on the need of, and producing, increasingly accurate nuclear data. Nuclear data is used in developing the next generation nuclear facility models, estimating current nuclear power plant core reaction outputs, and calculating storage container size and shielding thresholds for nuclear waste. Accurate modelling of nuclear reaction rates, energy spectra and cross sections are reliant on nuclear theories and the accuracy of nuclear data.


An important area of nuclear data for the modelling of nuclear fuel matrixes and nuclear waste storage is the (alpha,n) reaction in the alpha-particle energy range 2-7.5 MeV. The decay Trans-Thorium elements, found in nuclear fuel and nuclear waste, emit alpha-particles with energies up to ~7.5 MeV. The alpha-particles will interact with light nuclei via the (alpha,n) reaction to produce high energy neutrons. This reaction will be increasingly important for next generation nuclear fuels contained in light nuclei as, in comparison to current generation nuclear fuel, the relative number of heavier alpha-decaying nuclei is expected to be much higher and the neutron rate can vary from a fraction to many times the spontaneous fission neutron rate.


The nuclear modelling and transport codes Sources-4c, TALYS and GEANT4 are used by nuclear facilities (e.g. UK Nuclear National Laboratory) to calculate the (alpha,n) reaction rates and energy spectra for shielding calculations. The codes use current nuclear data (cross section data and nuclear levels of the compound nucleus) as input. Where this data does not exist, and has not been measured, theoretical calculations are used instead (e.g. GNASH pre-equilibrium). The use of the calculated spectra has resulted in large uncertainties of the order 10-35% [2]. These large uncertainties mean any next generation nuclear reactors and nuclear waste storage facilities will more shielding dependent on the upper limit of the uncertainties.

This PhD's intention of improving the accuracy of identified important nuclear data will reduce potential shielding costs of next generation nuclear reactors and nuclear waste storage facilities.

This PhD is supported by the UK nuclear data network; a collaboration which has recently been established between the Universities of Manchester, Surrey and York, and linking to relevant industry and national laboratories.


2. G. N. Vlaskin,1 Yu. S. Khomyakov, and V. I. Bulanenko, Atomic Energy, Vol. 117, No. 5, March, 2015