Provision of Technical Support to Perform an Independent Analysis of the UK HPR1000 In-Vessel Melt Retention by External Reactor Vessel Cooling Strategy

ONR is seeking to engage one the Technical Support Contractors (TSC) appointed on Lot 1 of its Technical Support Framework. The TSC is required to agree with ONR a strategy to independently confirm the validity of claims made on in-vessel retention ex-reactor vessel cooling strategy, based on the response to this specification. This includes the severe accident scenarios to be modelled. This should occur shortly after award of the contract.

Request from the RP the information needed to develop independent computer models (which ONR will formally submit to the RP as written Regulatory Queries (RQs)). For planning purposes the contractor should assume that data will be provided 6 weeks after each request. It is likely that several information requests will be required in order to ascertain all data required to build the model and run the SA scenarios.

Develop a UK HPR1000 model capable of modelling severe accident scenarios from initiating event to RPV failure or steady state. The model should include an appropriately detailed core and RPV lower head, a containment, a primary circuit thermal hydraulics model and an IVR tank and recirculation loop (if necessary).

Perform confirmatory analysis on a range of severe accidents scenarios