Reduced nuclear reactor footprint can add construction challenges
Some new advanced reactors tout a reduced footprint, but the more compact design can make installation more difficult
Details
Core information and root causes
Context
"[The AP1000 reactor from Westinghouse] was much simpler than previous reactors, with “60% fewer valves, 75% less piping, 80% less control cable, 35% fewer pumps and 50% less seismic building volume than usual reactor design”, and an emergency cooling system that works passively via gravity (and thus theoretically less susceptible to LOCAs.) The reactor was also designed to be prefabricated and installed on-site in large modules, reducing the requirements for site labor.
However, the AP1000 seems to have had significant constructability issues. The reduced footprint seems to have made everything much closer together and difficult to install - nuclear plants already tend to have constructability issues due to the amount of piping, wiring, and other services - requiring frequent design changes. There also seem to have been issues with prefabrication, with modules often behind schedule and out of spec, and often requiring significant rework (one downside of prefabrication is that problems are more difficult to fix.)"1