Read this for the context.
The first set of scenarios looks at the possible build out of Gen II+/III/III+ thermal reactors (i.e., current and advanced water-moderated reactors: PWRs, BWRs, HWRs etc.), over a 50 year time frame (2011 to 2060). The focus of this exercise is not to predict which reactor type(s) will predominate. In the next 1-2 decades, I suspect (given current and announced installation schedules) that it will be dominated by a mix of monolithic designs, such as the AP1000, APR-1400, CPR-1000, EPR, ABWR, PHWR, VVER-1000, as well as some small modular reactors like the mPower and NuScale.
The starting installed capacity in 2010 is set at 376 GW (all power rates are expressed as electrical rather than thermal output). The projection model is based on 5-year blocks (2011-2015, 2016-2020, etc.), for which a growth rate (multiplier) is specified, through to 2056-2060. Four scenarios are considered:
1. NCOL: WNA Nuclear Century Outlook (NCO) Low (anchoring to 602 GW in 2030 and 1140 GW in 2060)
2. NCOH: WNA High scenario (1350 GW in 2030, 3688 GW in 2060)
3. TR1: A mid-growth scenario that tracks between NCO Low and High, but which peaks at around 2050 and slowly declines thereafter
4. TR2: A high-growth scenario that is identical to NCO High through to 2030, after which the relative growth rate slows only gradually (absolute number of GW per year continues to increase).