Challanges

Common to all LFRs:

Corrosion and erosion of structural materials if good oxide protection layer is not maintained. Strict coolant chemistry control is required. Less of a concern for the NQ150 because of the relatively short lifespan (10 to 20 years) planned for the core module (which is subjected to the highest temperatures)
Lead solidification risk. Partially mitigated by using feed water temperature exceeding lead freezing temperature. Also, the NQ150 is equipped with electrical heaters
Opacity – difficult to monitor reactor vessel internals: Less of a problem in NQ150 since no need for fuel handling on site
Heavy reactor vessel requires careful seismic isolation
High initial fuel cost. All ~12% enriched uranium fuel must be purchased on day one. Nevertheless, preliminary economic analysis indicates very attractive economic viability of the NQ150 and the reactor has assured fuel supply for life and is not affected by market cost fluctuations