Report Of The President's Commission On
The Accident At Three Mile Island           > TMI-2 > Kemeny

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The Accident


Commission Findings:


1.  Planning for the protection of the public in the event of a radiological release that extends beyond the boundary of TMI was highly complex. It involved the utility and government agencies at the local, state, and federal levels. That complexity posed problems in the case of the accident at Three Mile Island; some of the written plans that existed had not been coordinated and contained different systems for classifying accidents and different guidelines for notifying government officials.

2.  In approving sites for reactors, the NRC has required licensees to plan for off-site consequences of radioactive releases only within the "low population zone" (LPZ), an area containing "residents, the total number and density of which are such that there is a reasonable probability that appropriate protective measures could be taken in their behalf in the event of a serious accident." As calculated for the design-basis accident for TMI-2, this zone was a 2-mile radius.

3.  Emergency planning had a low priority in the NRC and the AEC before it. There is evidence that the reasons for this included their confidence in designed reactor safeguards and their desire to avoid raising public concern about the safety of nuclear power.

4.  The NRC has not made the existence of a state emergency or evacuation plan a condition for plant licensing. A state may voluntarily submit a response plan to NRC for concurrence, and if the plan meets NRC guidelines -- which do not have the force of law -- the state receives a formal letter of concurrence. At the time of the accident, Pennsylvania did not have an NRC concurred-in plan. The NRC concurrence program has been called ineffective by federal and state emergency preparedness officials.

5.  The utility has the responsibility to prevent or to mitigate off-site radiation releases and to notify the government agencies designated in its emergency plan in the event that an emergency is declared. Federal, state, and local agencies are responsible for off-site response to radiation releases. At the  time of the TMI accident, the local and county governments had the  primary action role once notified of the emergency. None of the local communities within the 5-mile radius of the plant had emergency plans, and the existing county plans did not include detailed evacuation bf.   plans.

6.  At all levels of government, planning for the off-site consequences of radiological emergencies at nuclear power plants has been characterized by a lack of coordination and urgency. For example, a federal response plan in preparation since 1974 by federal emergency preparedness agencies was unfinished at the time of the accident because of an interagency jurisdictional dispute and lack of communication. Pennsylvania did not begin to develop a radiological emergency plan until 1975, even though nuclear power plants had been operating within its borders for at least a year prior to that time. People who attempted to generate interest in radiological emergency planning at the local level near TMI found local officials apathetic. Part of the reason for this was the attitude fostered by the NRC regulatory approach, and by Met Ed at the local level, that radiological accidents having off-site consequences beyond the LPZ were so unlikely as not to be of serious concern.

7.  Interaction among NRC, Met Ed, and state and local emergency organizations in the development, review, and drill of emergency plans was insufficient to ensure an adequate level of preparedness for a serious radiological incident at TMI.

8.  Although NRC personnel were on-site within hours of the declaration of a site emergency and were in constant contact with the utility, the NRC was not able to determine and to understand the true seriousness and nature of the accident for about 2 days, when the fact of extensive core damage and the existence of the hydrogen bubble were generally recognized within NRC.

9.  During the first 2- days of the accident, communications between the NRC Incident Response Center in Bethesda, Maryland, where the senior management was located, and the site were such that senior management officials found it extremely difficult to obtain up-to-date information. Communications were so poor on Friday morning that the senior management could not and did not develop a clear understanding of conditions at the site. As a result, an evacuation was recommended to the state by the NRC senior staff on the basis of fragmentary and partially erroneous information. Communications did not improve until Harold Denton, designated the sole source of information, arrived on the site and communicated with NRC headquarters, the Governor's office, and the White House by White House communications line.

10. The reality of possible evacuation was quite different from the theoretical planning requirements imposed by the NRC and Pennsylvania before the accident. The 5-mile emergency plans were developed according to a Pennsylvania requirement for emergency planning within a 5-mile radius of nuclear power plants. The Pennsylvania requirement was stricter than that prescribed by NRC, which only required TMI to have a plan for a radius to 2 miles. (See finding D.2.) It is known that the consequences of a postulated major release to the atmosphere from a reactor accident could lead to significant doses of radiation being received many tens of miles from the site of the accident. At TMI-2, although the radiation releases were significantly lower than the design-basis accident, evacuation was being considered for distances much greater than 2 miles. During the TMI accident, NRC believed that the consequences of the accident might extend far beyond the 2- or 5-mile radius. As a result, evacuation plans were hurriedly developed for distances of 10 and 20 miles from the plant.

11. During the most critical phase of the accident, the NRC was working under extreme pressure in an atmosphere of uncertainty. The NRC staff was confronted with problems it had never analyzed before and for which it had no immediate solutions. One result of these conditions was the calculational errors concerning the hydrogen bubble, which caused the NRC to misunderstand the true conditions in the reactor for nearly 3 days.

12. On Friday and Saturday, certain NRC officials incorrectly concluded that a hydrogen bubble in the reactor vessel would soon contain enough oxygen to burn or explode. Ignoring correct information supplied by a B&W employee and certain members of its own staff, NRC relied instead upon incorrect information supplied by other members of its staff and by others that sufficient oxygen was being formed from water radiolysis to reach a concentration sufficient for a burn or explosion. Based on this information, the NRC commissioners began formulating new recommendations for evacuation. On Sunday, NRC staffers obtained information from several national laboratories and from General Electric and Westinghouse that sufficient oxygen could not form. The Sunday information ended the concern about oxygen formation and evacuation. This incident suggests that NRC lacks sufficient knowledge and expertise in water radiolysis.

13. The role of the NRC commissioners and their decision-making process during the accident were ill-defined. Although the commissioners on Friday assumed responsibility for making recommendations to the Governor concerning protective action, there was no apparent procedure by which issues and staff recommendations were explored and resolved. The commissioners were preoccupied with matters such as the details of evacuation planning and the drafting of a press release.

14. Existing emergency plans were not designed to meet the demands of a protracted crisis. The plans had no mechanisms for establishing reliable communications among the on-site and the several off-site organizations responsible for various aspects of the emergency response.

15. There were no hospitals within 5 miles of TMI, but there were several hospitals within the expanded, proposed evacuation zones. The NRC estimated that it would be able to give officials a few hours "lead time" for evacuation. But hospital administrators   estimated they would need substantially more time to evacuate    patients.

16. During the TMI accident, the actual radiation levels outside the plant were low, but there was uncertainty about the possibility of serious releases on short notice. Federal and state officials disagreed about the nature of the information on which to base evacuation decisions and other protective actions during the emergency. Some officials based their decisions on actual radiation exposure levels, while others based their decisions on concerns about potential releases of large amounts of radioactivity. For example, the Pennsylvania Bureau of Radiation Protection told the Governor on Friday that radiation levels indicated that no protective action of any kind was required; on that same morning, NRC Chairman Hendrie recommended that pregnant women and young children be advised to leave the area near the plant because of his concern about possible releases of radioactivity.

17. At approximately 12:30 p.m., March 30, Governor Thornburgh advised pregnant women and preschool aged children to leave the area within a 5-mile radius of TMI until further notice. A substantial number of other persons, including health professionals, voluntarily left the area around the plant during the weekend of March 30 through April 1. The advisory to pregnant women and preschool children was lifted on April 9.

18. Throughout the accident, the Pennsylvania Emergency Management Agency (PEMA) received reports concerning conditions at the site from the Bureau of Radiation Protection. During the first 2 days of the accident, however, the director of PEMA also received background information on the status of the plant from the Governor's office by attending meetings and press conferences and relayed that information to county organizations, which, in turn, informed the local civil defense directors. Starting Saturday, the PEMA director was no longer included in these meetings with the result that PEMA and county and local civil defense organizations had to rely primarily on the news media for information about conditions at the site. They found this an unsatisfactory source of information and believed that this arrangement compromised their effectiveness in responding to the accident.

19. The TMI emergency plan did not require the utility to notify state or local health authorities in the event of a radiological accident. (See also finding C.7.)

20. For over 25 years, the use of blocking agents such as potassium iodide to prevent the accumulation of radioiodine in the thyroid gland has been known. The effectiveness of potassium iodide administration for thyroid gland protection in the event of releases of radioiodine was recognized by the National Council on Radiation Protection and Measurement in 1977. The Food and Drug Administration authorized use of potassium iodide as a thyroid-blocking agent for the general public in December 1978. However, at the time of the TMI accident, potassium iodide for this use was not commercially available in the United States in quantities sufficient for the population within a 20-mile radius of TMI. At the time of the accident. Met Ed had no supply of potassium iodide on-site. A crash effort by the federal government and private industry resulted in delivery of substantial supplies of potassium iodide to Pennsylvania within 2 days of the decision to obtain such supplies.