The Aftermath of the Three Mile Island Nuclear Accident: Government Involvement and Lessons Learned

On March 28, 1979, a partial meltdown occurred at the Three Mile Island nuclear reactor (TMI-2) in Pennsylvania, USA. This incident would go on to shape the nuclear industry and prompt significant government intervention to ensure nuclear reactor safety.

Government's Role in Responding to the Accident

The government's response began almost immediately with shutdowns of the reactor and a gradual process of repairing and making the plant safe. After the immediate crisis, the reactor was dismantled to be permanently shut down. The government provided approval authority and oversight for the remediation plan implemented by the utility company that held the license for the nuclear electric generating facility.

However, beyond the technical and operational aspects, the government's involvement also included political posturing, finger pointing, and blame blasting. Many politicians used the accident as a platform for their own political gains, resulting in media coverage filled with governmental actions that were less geared towards resolving the issue than capitalizing on it.

Despite these less-than-helpful behaviors, the government did take some positive actions. Licensing authorities mandated retraining in recognizing and preventing the formation of steam bubbles in pressurized water reactors. Additionally, they mandated critical components related to reactor safety systems be shared, with legal penalties for non-compliance.

Root Cause and Follow-Up Actions

The root cause of the fuel meltdown at TMI was found to be a manufacturer of primary reactor overpressure valves not sharing information about a recurring problem with their valves sticking open even when indicating closed. This lack of transparency among the industrial sector highlighted the need for better communication and information sharing.

In response, the Institute of Nuclear Power Operations (INPO) was formed by power plant license owners to meet the information sharing mandate of licensing authorities in the U.S. This organization played a crucial role in ensuring that the lessons learned from the TMI incident were not only applied but also shared widely within the industry.

Long-Term Impact and Industry Reforms

Long-term, the government’s involvement led to significant changes in the nuclear industry. Appointments of two commissions to study the accident and determine the exact cause set the stage for substantial improvements. Emergency procedures were changed from event-based to symptom-based, and training and examination programs were completely revamped. As a result, nuclear reactor operators in the United States became among the best trained and most accurately examined in the world.

The changes extended far beyond training and procedures. The control room layout was logically reorganized, and post-accident effluent monitoring capabilities were added. Regulatory oversight was significantly improved, and the industry was fundamentally transformed. In many ways, the industry before TMI could be considered infantile compared to the robust and mature industry that emerged from the aftermath.

In hindsight, the improvements implemented after the TMI accident were truly groundbreaking, though it is disheartening to recognize that such improvements were necessitated by a serious accident. While TMI set the industry back to a point from which it has never fully recovered, the incident also catalyzed the implementation of long-overdue improvements that would have significantly benefited the industry from the outset.

Overall, the Three Mile Island accident had far-reaching consequences, both in terms of immediate safety measures and long-term industry reforms. It underscored the importance of transparency, information sharing, and robust regulatory oversight in the nuclear sector.