Three Mile Island and Challenger Disaster Memos Compared

Introduction to Two Preventable Disasters

The series of memos entitled "The Filthy Five from the Three Mile Island Disaster" details how a conflict over the operation of the Three Mile Island Nuclear Facility — between the Babcock & Wilcox Company and the facility's operators — led to the greatest nuclear power disaster in United States history. While the builders of the reactor warned the operators that their operating procedures were incorrect, the operators refused to accept those findings and continued to run the facility improperly, ultimately producing a catastrophic nuclear accident.

The Three Mile Island Memos: Ignored Warnings

The initial memo, "Memo 1," describes two incidents in which operators did not follow procedures as recommended by the Babcock & Wilcox (B&W) company (Kelly). In response, "Memo 2" — written by a facility manager — stated that the other operators "responded in the correct manner considering how they have been trained" (Walters). This wording suggests that operators may have been trained in incorrect procedures, but the memo was framed in a way that deflected responsibility away from those directly involved in the two initial incidents.

Babcock & Wilcox were extremely emphatic in "Memo 3" that the procedures used by the operators — primarily bypassing the high pressure injection (HPI) system after a Loss of Coolant Accident (LOCA) — were incorrect and could lead to "core uncovery and possible fuel damage" (Dunn 3). Even after B&W followed up with "Memo 4," specifically instructing the operators when to bypass the HPI system and when not to, the operating managers refused to accept the builders' recommendations (Dunn 4).

Instead, the operators produced the final memo, "Memo 5," stating their belief that following the procedures outlined by B&W could cause the Reactor Coolant System (RCS) to solidify. On those grounds, they declined to follow the recommended procedures. As a result, the Three Mile Island facility suffered a catastrophic meltdown: the core became uncovered, the fuel rods heated to damaging levels, and the facility and surrounding area sustained severe harm.

Operator Arrogance and the TMI Meltdown

Had the operators followed the procedures recommended by the reactor's builders, the disaster could have been prevented. The operators believed they understood the reactor's behavior better than those who had designed and constructed it. It was in the grey area between design intent and actual field operation that they made their critical mistake. While complex machines sometimes require minor adjustments from their initial design specifications, the operators took this principle far too far. They genuinely believed that their operational experience made them more capable of diagnosing problems than the reactor's own designers.

As a result of this arrogance, they continued to bypass the high pressure injection system whenever a loss of coolant accident occurred — precisely the scenario B&W had warned against. As the company predicted, this led to the uncovering of the core rods and a subsequent buildup of heat. Because the operators were unable to bring the coolant system back online, the heat continued to escalate until catastrophic damage was done to the reactor. The U.S. Nuclear Regulatory Commission's account of the accident confirms that the failure to properly manage the HPI system was central to the disaster's progression.

Conclusion: Organizational Failure as Root Cause

Whether the Challenger disaster was caused by the failure of the O-ring or the putty that was supposed to seal it, the shuttle should never have been launched until a definitive answer was found. Irv Davids admitted in "Memo 2" that he had reservations about the decision precisely because the exact cause of the problem remained unknown. Yet "Memo 1" clearly demonstrates that program directors were primarily focused on budgetary concerns. Had those directors been more concerned with safety and less preoccupied with flight schedules and financial projections, the Challenger disaster might well have been avoided.

Both the Three Mile Island and Challenger disasters share a common thread: in each case, clear technical warnings were documented in writing, and in each case those warnings were overridden by institutional priorities — whether operational arrogance or financial pressure. The internal memos from both disasters stand as powerful evidence that the human and organizational factors were at least as consequential as any mechanical failure.

Works Cited

Cook, R. Memo 1 (Cook). 23 July 1985. The Challenger Disaster.

Davids, Irv. Memo 2 (Davids). 17 July 1985. The Challenger Disaster.

Dunn, Bert. Memo 3 (Dunn). 9 February 1978. The Filthy Five from the Three Mile Island Disaster.

Dunn, Bert. Memo 4 (Dunn). 16 February 1978. The Filthy Five from the Three Mile Island Disaster.

Hallman, D.F. Memo 5 (Hallman). 3 August 1978. The Filthy Five from the Three Mile Island Disaster.

Kelly, J.J. Memo 1 (Kelly). 1 November 1977. The Filthy Five from the Three Mile Island Disaster.

Walters, J.F. Memo 2 (Walters). 10 November 1977. The Filthy Five from the Three Mile Island Disaster.