![]() The accident involved numerous preexisting plant conditions that aggravated the accident progression, was dominated by unanticipated human actions, produced thermal-hydraulic phenomena in the RCS that were previously unknown to most people in the nuclear power community, and produced many instrumentation readings that were misinterpreted. The very early stages of the accident had three precursors at other nuclear power plants and at least two at TMI-2. The TMI-2 accident was most similar to scenarios described in the Reactor Safety Study (RSS), which had been prepared for the NRC by a team at the Massachusetts Institute of Technology in 1973–1975. The accident was unlike any event considered in the plant’s final safety analysis report (FSAR), although certain of its features were similar to those of specific safety analysis events. At that time, about half the core had melted and relocated. The TMI-2 accident was a “beyond design-basis accident.” This section discusses the first four hours. Brief descriptions of the accident, including graphical illustrations of the core damage and discussion of improvements because of it, are also provided in recently published textbooks. The NRC summarized near-term lessons learned and developed new and proposed regulations for licensees and license applicants. Immediate responses from licensees of other nuclear power plants were required by NRC Bulletins requesting information and requiring specified actions. The TMI-2 accident is described in numerous reports and publications. The intent of this two-part piece is to present on this 40th anniversary of the accident a more complete and accurate description of its causes, lessons learned from it, and improvements that have been made since. Part two will discuss improvements that have been made by both the industry and the NRC over the past 40 years. It concludes with responses to specific statements made in that article. ![]() This article, part one of two, presents insights from the accident and addresses several issues raised by a previous Nuclear News article on the subject. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |