Protection from potential tsunami effects is a design criterion for coastal nuclear power plants, especially on the U.S. Pacific Coast and in Puerto Rico. Because of the uncertainties involved in the probabilistic approach, the U.S. Nuclear Regulatory Commission uses a deterministic approach to conservatively estimate tsunami runup, drawdown, and the resulting effects at proposed nuclear power plant sites. However, because of the lack of good data to verify the tsunami models used, very conservative input parameters are used in tsunami analysis. The results may lead to overly conservative and expensive designs for the protection of nuclear power plants from the effects of tsunamis. We, therefore, call for tsunami research in specific areas in order to obtain more realistic estimates of tsunami effects in the future.