On March 28, 1979 the Three-Mile Island Unit-2 nuclear power plant experienced a feed system failure which prevented the steam generators from removing heat from the plant. The reactor automatically shutdown but, without the feed system to cool the primary, the pressure in the primary system (the nuclear portion of the plant) began to increase. In order to prevent that pressure from becoming excessive, a relief valve opened. The valve should have re-closed once the pressure dropped by a small amount, but it didn’t. The only indication available in the control room showed the valve in the closed position, but that indication was erroneous, representing only that the signal to close the valve (pressure below a set value) had been sent to the valve. Nothing in the system verified the actual valve position. This stuck-open valve caused the pressure to continue to decrease in the system (and ultimately provided a path for spewing thousands of curies of radioactive material into the atmosphere), but the false shut indication prevented the operators from taking actions to mitigate their severe loss of coolant accident.
The primary relief valve design had a history of sticking. That same valve had been involved in at least nine other minor incidents prior to the TMI incident. Most notably, eighteen months before TMI, a similar incident had occurred in another nuclear plant involving a loss of feed and rising temperatures shutting down the plant. In that incident, the plant was just starting up after a maintenance shutdown, so the power level and temperature of the system were not as dangerously high as at Three-Mile Island.
The plant supervisors reported this incident to the NRC–even going so far as to note the disastrous consequences that might result if such an incident occurred during operation at power–but the TMI-2 operators were not aware of the earlier incident.
Several factors contributed to the severity of the TMI disaster, but the false indication of that pressure relief valve was arguably the worst contributor.
I became intimately familiar with the TMI incident because I was in training as a US Naval reactor operator at the time of the event. The Naval Reactors Office (a safety oversight office reporting to the Department of the Navy and the DOE) drilled us on every aspect of the TMI design and operations that led to or aggravated the TMI incident. One aspect that was clearly never going to happen in a Naval reactor, however, was a failure to learn from the earlier stuck-valve incidents.
The Naval Nuclear Power program had long had a model incident reporting system in operation. Any incident that occurred in a Naval nuclear plant, whether it had dire consequences or just resulted in a close call, went out to every plant operator in the Navy. I was a submariner, and it often seemed that every incoming communication included another set of incident reports. We were required to read and sign every new incident report–no matter how minor–that had any chance of impinging on our watch stations or maintenance responsibilities. Naval Reactors was quick to respond to incidents that demonstrated systemic and procedural flaws by sending out action change notices that went into effect until formal revisions to the operating manuals could be published.
After TMI, the NRC took a cue from Naval Reactors and initiated a simple incident reporting system.
Today, errors that result in plant damage and near-misses are collected and published to operators across the country.
Recently the Institute for Healthcare Improvement (IHI) Open School has been encouraging medical personnel to share their mistakes with their peers in the hopes that their errors, too, might prevent future disasters. One of the IHI videos I saw, IHI: Perspectives: The Mistake (part 1) includes a talk by Michael Leonard, the Physician Leader for Patient Safety at Kaiser Permanente, about an incident of his
own in which he accidentally grabbed the wrong vial and re-injected a patient with a paralyzing agent when he had intended to bring the man out of anesthesia. Dr. Leonard says that, as head anesthesiologist of his hospital, he was in a position to enact a change in procedure to prevent anyone else making the same mistake ever again. When I saw that video, my first thought was, “What about anesthesiologists in the other thousands of hospitals and surgical centers in the US? What’s to prevent their anesthesiologists from making the same mistakes?” The IHI Open School program–which addresses healthcare students–is a good one, but I think it could be much more far-reaching and effective. My proposal is twofold.
First, let’s establish a national medical incident reporting system. People like Don Berwick, Atul Gawande, and Kent Bottles have taken steps to bring medical error out of the closet and into the mainstream where they can have positive effects. A comprehensive system for collecting and deliveringthose errors could have a vaccinating effect across the country. Every iatrogenic infection, injury, or death reported could result in untold infections and injuries prevented and lives saved.
Second, for greatest efficiency, immediacy, and impact, this incident reporting system should take the form of a medical error Wiki. Every medical professional should have the right to log on and share her or his errors. That Wiki should be supported by alerts to email but just for the same of rapidity of promulgation, through social media such as LinkedIn, Facebook, and Twitter.
Life Saving Errors is an official panel proposal for SXSW Interactive 2011. If you like his ideas, why not take a moment and vote for his proposal at the SXSW site. Dennis, a negotiator and investigator for MedicalBillDog.com (a medical billing advocacy service), spent a decade improving documents for IBM. As liaison to other computer companies, Dennis’s win-win negotiating style won him the nickname “Switzerland” from his work team. He notes “with a little luck, my panel proposal will be approved for SXSW. If not, I’ll still be looking to start a wiki for the purposes described in my proposal.”
An avid scuba diver and martial artist, Dennis enjoyed an active, healthy lifestyle until a martial-arts accident jarred loose a damaged disc in his lower spine. Chronic pain from degenerating discs in his lower back led to one medical procedure after another-X-rays, MRIs, epidural injections, spinal fusion surgery, physical therapy, and lots of medication. Hoping to find an explanation for the unbelievable size of his medical bills, Dennis studied to pierce the fog of codes and abbreviations. What he found astonished him: over $5,000 in errors in the first two pages alone.