Memories of TMI

Frazier Bronson

On Wednesday, 28 March 1979, I was working for Radiation Management Corporation (RMC), having been in Philadelphia for eight years and now managing the Chicago office. I was quite familiar with TMI since RMC was doing its Environmental Monitoring program, Emergency Medical program, providing mobile WBC services, and since I had spent quite a bit of time at the plant before startup writing procedures. Very early Thursday morning, I was awakened by a phone call from Sydney Porter (then at his company, PCI) who said there were problems at TMI and "asked" that I come out there—"and bring your mobile lab." I asked how long I should be prepared to stay—and he said, "Plan for 2–3 days." I left 30 days later; those two changes of clothing were getting pretty ripe by then.

As I was flying in from Chicago, someone else was bringing the mobile lab from Philadelphia. It was a very simple (and small) lab having only a Ge(Li) gamma spec system in a good lead shield and a smear counting system—all in a 10-foot-long "bread truck" van. That was my cozy "home" for 14 hours a day. We were the second lab there, arriving shortly after the Nuclear Regulatory Commission van, manned by Jim Kotten. As the two earliest arrivals to the TMI Visitor Center—which soon became "Trailer City"—we got the prime parking spots center: close to the toilets and next to each other so we could cross-check sample results.

Our task was to support Met Ed and Syd in determining the plant effluent activity, since all releases were via unmonitored pathways. Field sampling technicians were taking air samples using particulate and charcoal filters. It was quite normal to see them approaching with samples hanging from a 10-foot-long pole and asking us to count them. I quickly created a new counting geometry with the lid of the shield open and the sample taped to the ceiling. The dose rate was from all the various xenon and krypton gasses that like charcoal very much, not the radioiodines we were concerned about; they later learned to blow clean air through them for a few minutes to remove much of the adsorbed gas. I don't think that we ever saw any environmental or effluent samples with detectable 131I, contrary to the news reports. I suspect those that did report it were really measuring the xenons. Shortly thereafter, the industry transitioned from charcoal to silver zeolite, which greatly minimizes those problems.

Since we were continuously presented with different samples to count, we needed new efficiency calibrations. I asked our Philadelphia labs to send me up some calibration master solutions. But then Trailer City was very crowded, with lots of news media folks and cameras always around. So I waited until late at night when the crowds thinned, removed the radioactive labels from the containers, put them and other supplies in a brown paper bag, and waited in line at my sample preparation room—the toilet. After locking the door (yes, it was a single holer) I then made the calibration dilutions. Since this was a somewhat lengthy process, and there were other "civilians" in line behind me, I had to periodically make bathroom noises so they wouldn't discover my true mission.

The mobile WBC system that I had built eight years earlier also happened to be on-site at the time of the accident. But when they declared a site emergency, our operator had to leave, took the keys with him, and disappeared. We couldn't find him or a spare set of keys. We had to go back onto the site in full PCs and respirator and hot-wire the truck and bring it over to Trailer City. Of course, growing up in the Midwest, I didn't know how to do that; so I asked the techs in the room if anyone was from New Jersey. When a hand was raised, I was sure I had found someone that could.

Unlike our current "peak oriented" software, at that time we were using "spectral shape fitting" software, which required an accurate "background" spectrum. But the background was varying in shape. Eventually we created two separate reference spectra, one when the xenon cloud was high and the other when it was low and we were in it. Those two shapes were included in the library and analyzed along with the other plant nuclides of interest. It worked very nicely.

A week or so later, Lew Helgeson got his mobile WBC there and was tasked to count the public. But our primary task was to assay the workers. I remember very well being in the WBC unit when the five HP techs who took that first primary coolant sample came over for their counts. These were the best people there, all highly trained and extensively prepared and dressed out to avoid any internal uptakes. If anybody should have not been worried about internal dose, it should have been them. But apparently not, as I can still remember the very obvious looks of relief as their assays showed minimal internal contamination. This points out the very important usefulness of tools like the WBC, which can provide immediate feedback to concerned workers, and especially the public, that their fears are likely unfounded.

The major negative experience was the extreme differences between what I knew about nuclear plants and specifically what was happening at TMI vs. what was being reported in the news. Some of it was clearly our industry's fault from not having experienced and informed spokespersons. Some of this is because this accident (and Chernobyl and Fukushima) are long-term, evolving, and somewhat unpredictable events; even the best spokesperson will make some predictions that will be wrong. And some of the bad reporting is just a desire for sensational statements or outright dishonesty by the media. A different part of RMC was also acting as consultants to one of the networks, where each morning someone decided what the story was going to be that day and sent crews out to gather "news" to support the story. We witnessed them placing "for sale" signs in yards, taking videos, and then removing the signs to support the story that later came out of people moving from Middletown. However, interviews and press coverage of me were fairly reported, at least the small part that was reported.

From the professional standpoint, this was one of the most rewarding experiences of my long career, only recently equaled by supporting Fukushima projects the first five years after that accident. My experiences in this very dynamic and challenging TMI emergency-response situation were the basis for some very successful products I was able to create—and am still working to improve today. A year later Canberra purchased RMC, which allowed for these ideas to become products.

  • The long waiting time in line for the WBC led to the FastScan WBC. It occupies only 20% of the space of the lay-down units that we had at TMI, can give the same sensitivity with only 4% of the counting time, and gives reliable results instantly. The first FastScan was delivered to TMI about two years after the accident. A few years later, eight units were sent to the Chernobyl area. And 32 years later, we delivered about 60 FastScan units, including 20 mobile ones, to the Fukushima area.
  • The difficulty to quickly create efficiency calibrations for unusual sample geometries was the impetus to create the ISOCS mathematical calibration software. No radioactive sources are needed. Now users can sit at their computers for this, instead of annoying those in the line behind them at the crowded local toilet.
  • TMI, Chernobyl, and Fukushima have all needed reliable and low-cost thyroid monitoring of workers and especially the public. Field workers who take environmental and plant samples have long needed the ability to perform reliable gamma spectral assays in the field, rather than waiting for laboratory results. The ISOCS Ge counting system was developed 20 years ago and can do all that except the "low-cost" part. The current shielded CZT system and the Data Analyst gamma spectroscopy system we are using now does all that at a low cost and can be carried by one person and operated all day on batteries.

Interesting but unconfirmed tidbit: A reliable source (one who should know) said he was at the control point when President Carter and his entourage left the contamination area after their "assessment" tour. All their pocket chamber dosimeters (remember, this was 40 years ago) were read out by the techs manning the control station and the (minimal) doses recorded—but Jimmy's was off-scale. Not wanting to spend time explaining this to the nuclear-engineer President, and many others, he simply wrote down the previous guy's dose; entirely appropriate and very practical.

My first (of many) trips there lasted 30 days, during which I generally worked 14 or more hours a day. Parking toward the end was very crowded, so most of us parked along the highway. One evening I came back to find a parking ticket on my windshield and a No Parking sign next to the car—which wasn't there when I parked the car. An explanation letter to the state authorities resolved the ticket issue. That sign is now proudly displayed in my garage, where I see it each night as I come home; it brings back those good memories of my experiences at TMI.