Nuclear Construction Times for the Second and Subsequent Plants at a Multi-Plant Site Are Overstated
EMD-80-01: Published: Oct 10, 1979. Publicly Released: Oct 10, 1979.
- Full Report:
Many cost analyses project further increases in the cost of nuclear powerplants, based in part on lengthening construction times. It is important that government data accurately reflect the current actual construction times and trends in order to provide a correct basis for these analyses.
The "Construction Status Report" (NUREG), the official document on the status of nuclear construction, indicates a continued lengthening of nuclear construction times beyond the 102 months averaged in 1978. A GAO analysis of nuclear powerplant construction progress over the past 24 months indicates that the rate of nuclear plant construction, instead of slowing, has stabilized. The precise extent of this overstatement of constuction time is difficult to determine. NUREG measures construction duration from a point called mobilization, which occurs prior to site preparation and commencement of structural construction, to fuel load date. At sites with more than one plant, the start of mobilization and site preparation is usually the same for all plants, even though the plants are not scheduled to reach their fuel load dates simultaneously. The construction is deliberately staggered, but the NUREG format does not take this into account in estimating construction time. Thus the apparent lengthening observed in nuclear powerplant construction durations estimated by NUREG is much larger than is actually the case. GAO adjusted the NUREG estimate of construction duration through 1978 by correcting for overstatement for multiple plants; the GAO trend indicates lower construction times and a stabilization in construction at around 90 months.