Provision of technical support services to perform independent confirmatory safety analysis

ONR is seeking to engage one of the Technical Support Contractors (TSC) appointed on Lot 1 of its Technical Support Framework. The TSC is required to develop a thermal hydraulic system code computer model of the UK HPR1000. 1) A pragmatic approach to its development should be taken to ensure the model can be applied to a selection of fault transients without expending unnecessary effort developing redundant capabilities that are not required. 2) The computer model should utilise a point kinetic approach for the reactor physics for the initial work scope. However, the model should be developed with a view to coupling with the more sophisticated reactor physics model in the final phase. 3) The computer model should include a basic consideration of containment response. A more detailed containment model is not envisaged at this time but there is value in providing the capability and flexibility to develop and couple such a modelling if containment behaviour emerges as an area of regulatory interest. Develop a Core Physics computer model of the UK HPR1000. 1) The TSC will use geometric and isotopic data to derive a set of neutron cross sections for each proposed fuel assembly type as a function of irradiation and other suitable dependencies. Given the proposed fuel loading pattern, this will be used to determine the nominal power distribution for full-power conditions. The nuclear data derived will need to take account of the spectral history of each fuel assembly in the equilibrium core to determine appropriate nuclear data. 2) The TSC will use the nuclear data produced in 1) to develop a 3D, transient core model suitable for use as part of a wider model for the purposes of fault transient analysis. The adequacy of the predicted steady state performance will be confirmed by comparison against core power-distribution data supplied.