Cost estimation for Moltex Stable Salt Reactor

UK

The Moltex Stable Salt Reactor based on Uranium (SSR-U) consists of a new Generation IV nuclear reactor based on the use of molten salts as nuclear fuel and primary coolant.

The SSR-U is an ultra-low-power nuclear reactor. The 20MWth reactor is fuelled for 25 years of continuous operation at 80% power, which is completely and directly decommissioned after its final shutdown. The fuel is contained in pins which are cooled down by the natural circulation of molten salts. The primary coolant is refrigerated through a gas secondary loop via heat changers installed inside the reactor vessel. The nuclear reaction is passively controlled during normal and off-normal operation and it is provided with a beyond-design basis accident shutdown system remotely controlled.

Moltex has developed a conceptual design for the reactor and nuclear heat supply system.

IDOM was requested to, starting from the conceptual design, elaborate a ROM-4 cost assessment for the Nth of a kind reactor, following a bottom-up approach including a split list of main items. IDOM proposed the AACE Institute methodology for class ROM-4 based on factored estimating methods such as gross unit costs, ratios, parametric modeling, etc., complemented by direct vendor assessments. IDOM assembled a short team of nuclear and civil engineers properly supported by external advisors from goods manufacturers, construction experts, supply managers, etc. and raw materials, labour costs and COTS items price industrial databases.
IDOM delivered the following assessments:

1. SSR-U cost assessment:

• • Contact with suppliers and goods manufacturers.
  • Optimistic/most probably/pessimistic scenario.
  • Civil Design and building budgeting.
  • Uranium specific price study.
  • MonteCarlo probabilistic assessment.
  • Technology CAPEX comparison.
  • Detailed breakdown structure.
  • Item manufacturing assessment.

2. SSR-U cost assessment assumptions:

• • Price assumptions.
  • Manufacturing assumptions.
  • Construction, installation & commissioning assumptions.
  • Decommissioning assumptions.
  • Nth of kind extrapolation.
  • Reactor building assumptions.

3. SSR-U decommissioning cost assessment:

• • International structure for decommissioning of NI.
  • Technical approach to reactor decommissioning.
  • Graphite decommissioning strategy approach.
  • Atomized cost assessment.

4. SSR-U cost assessment risk, opportunities & uncertainties:

• • Lessons learnt collection from historical and recent nuclear new build projects.
  • Opportunities to reduce nuclear construction costs.
  • Risk & opportunity identification, categorization – legal, regulatory, social, economic, environmental, technical,… – & evaluation according to probability and impact – low, medium, high -.
  • Uncertainties identification and description.
  • Opportunities identification and evaluation.

Advanced Reactors & SMR