Summary: It is uncertain if an when Cuba's nuclear power reactors will be operational. It appears that no progress has been made on the construction of the reactors since GAO issued its last report on this subject (GAO/RCED-92-262, Sept. 1992). The civil construction, such as floors and walls, of the first reactor is estimated to be more than 90 percent complete, while the second reactor is only between 20 to 30 percent complete. However, if Cuba obtains the assistance necessary to finish building the reactors, several concerns must be resolved. These include the quality of the civil construction completed so far, the lack of a regulatory organization, and the adequacy of operator training. Although the reactor will have a containment building and an emergency core-cooling system, which lessens the likelihood of a radiation escape during an accident, the containment dome was not designed to withstand pressures as great as U.S. containment structures can withstand. GAO concludes that continued monitoring of Cuba's progress toward completing the reactors is warranted.