To determine whether the process NRC used was credible when deciding  to allow Davis-Besse to delay its shutdown, we evaluated NRC guidelines  for reviewing licensee requests for temporary and permanent license  changes, or amendments to their licenses. To determine whether NRC is taking sufficient action in the wake of the  Davis-Besse incident to prevent similar problems from developing in the  future, we reviewed NRC’s lessons-learned task force recommendations,  NRC’s analysis of the underlying causes for failing to identify the corrosion  of the reactor vessel head, and NRC’s action plan developed in response to  the task force recommendations. 1.) 2.) 3 and 4.) NRC’s Actions to Oversee Davis-Besse Did Not Provide an Accurate Assessment of Safety at the Plant

NRC’s inspections and assessments of FirstEnergy’s operations should  have but did not provide the agency with an accurate understanding of  safety conditions at Davis-Besse, and thus NRC failed to identify or prevent  the vessel head corrosion. More  broadly, NRC had a range of information that could have identified and  prevented the incident at Davis-Besse but did not effectively integrate it  into its oversight. NRC Did Not Fully Communicate Indications

NRC was not fully aware of the indications of a potential problem at Davis- Besse because NRC’s process for transmitting information from resident  inspectors to regional offices and headquarters did not ensure that  information was fully communicated, evaluated, or used. After the corrosion was discovered, NRC analyzed the problems that led to  the corrosion on the reactor vessel head and concluded that FirstEnergy’s  programs for overseeing safety at Davis-Besse were weak, as seen in the  following examples:   Davis-Besse’s corrective action program did not result in timely or  effective actions to prevent indications of leakage from reoccurring in  the reactor coolant system. NRC’s Process for Deciding Whether to Allow a Delayed Davis- Besse Shutdown Lacked Credibility

Although FirstEnergy operated Davis-Besse without incident until shutting  it down in February 2002, certain aspects of NRC’s deliberations allowing  the delayed shutdown raise questions about the credibility of the agency’s  decision making, if not about the Davis-Besse decision itself. Three of these six reactors had identified circumferential cracking. Despite NRC’s responsibility for ensuring that the public is adequately  protected from accidents at commercial nuclear power plants, NRC does  not have specific guidance for shutting down a plant when the plant may  pose a risk to public health and safety, even though it may be complying  with NRC requirements. NRC has  not yet taken action on these recommendations. These actions  are even more important because the nation’s fleet of nuclear power plants  is aging. Develop specific guidance and a well-defined process for deciding on  when to shut down a nuclear power plant. NRC  also expressed concern about the report’s characterization of its use of risk  estimates—specifically the report’s statement that NRC’s estimate of risk  exceeded the risk levels generally accepted by the agency. Completion of  further inspection guidance changes expected in March 2004. Also, revise guidance for considering plant  conditions during licensing action and amendment reviews. GAO Comments

1. 2. It does not address important aspects of  decision-making involved in deciding whether to shut down a plant. However, NRC did not take any additional  action. The Nuclear Regulatory Commission Should Report on Progress in  Implementing Lessons Learned from the Three Mile Island Accident.
Why GAO Did This Study

In March 2002, the most serious safety issue confronting the nation's commercial nuclear power industry since Three Mile Island in 1979 was identified at the Davis- Besse plant in Ohio. After the Nuclear Regulatory Commission (NRC) allowed Davis-Besse to delay shutting down to inspect its reactor vessel for cracked tubing, the plant found that leakage from these tubes had caused extensive corrosion on the vessel head--a vital barrier preventing a radioactive release. GAO determined (1) why NRC did not identify and prevent the corrosion, (2) whether the process NRC used in deciding to delay the shutdown was credible, and (3) whether NRC is taking sufficient action in the wake of the incident to prevent similar problems from developing at other plants.

What GAO Found

NRC should have but did not identify or prevent the corrosion at Davis- Besse because its oversight did not generate accurate information on plant conditions. NRC inspectors were aware of indications of leaking tubes and corrosion; however, the inspectors did not recognize the indications' importance and did not fully communicate information about them. NRC also considered FirstEnergy--Davis-Besse's owner--a good performer, which resulted in fewer NRC inspections and questions about plant conditions. NRC was aware of the potential for cracked tubes and corrosion at plants like Davis-Besse but did not view them as an immediate concern. Thus, NRC did not modify its inspections to identify these conditions. NRC's process for deciding to allow Davis-Besse to delay its shutdown lacks credibility. Because NRC had no guidance specifically for making a decision on whether a plant should shut down, it used guidance for deciding whether a plant should be allowed to modify its operating license. NRC did not always follow this guidance and generally did not document how it applied the guidance. The risk estimate NRC used to help decide whether the plant should shut down was also flawed and underestimated the amount of risk that Davis-Besse posed. Further, even though underestimated, the estimate still exceeded risk levels generally accepted by the agency. NRC has taken several significant actions to help prevent reactor vessel corrosion from recurring at nuclear power plants. NRC has required more extensive vessel examinations and augmented inspector training. However, NRC has not yet completed all of its planned actions and, more importantly, has no plans to address three systemic weaknesses underscored by the incident. Specifically, NRC has proposed no actions to help it better (1) identify early indications of deteriorating safety conditions at plants, (2) decide whether to shut down a plant, or (3) monitor actions taken in response to incidents at plants. Both NRC and GAO had previously identified problems in NRC programs that contributed to the Davis-Besse incident, yet these problems continue to persist.