The Three Mile Island, TMI Reactor accident
March 28, 1979



TMI about TMI,  Too Much Information about Three Mile Island


Presented at the National Radiological Emergency Preparedness Conference

Sacramento, CA April 29, 2015

Abstract -- The morning of the Three Mile Island accident, March 29, 1979, the Department of Energy Radiological Assistance Program (RAP) Team at the Brookhaven National Laboratory (BNL) was activated to respond and support the Pennsylvania State Health Department. The response was largely ad hoc since no full-scale exercises of nuclear power plant accident response had yet been conducted. Members of the BNL RAP Team were airlifted by helicopter from BNL.  As a member of that team these are my reflections on the successful mission to sample the environment, consolidate the data, and what our team did to unravel the environmental impact of the releases from the plant over the first few days of the crisis. This memoir looks back on a first-hand insider's view of what went on behind the scenes, the media reports, and the reactions and overreactions as the crisis evolved.  I hope that my observations of this accident and what I have found that it has in common with other emergency responses that I have participated in over the past 49 years will prove useful to you. In my experience many of them hold true whether you're a volunteer firefighter, a member of the Red Cross, or helping with a police response.


Why did I make this web page?

I was a member of the DOE Region 1 Radiological Assistance Team that responded to the accident at TMI in 1979.  A friend who is still in the radiation response business thought that the folks at the 2015, National Radiological Emergency Preparedness Conference in Sacramento, would appreciate some of my stories and encouraged me to pass them on.  I hope that there is something to be gained from reading the experiences of someone who responded to an actual serious reactor accident even long after it occurred.  Also, looking back, there was a lot that was fun that happened while I was there, and I wanted to share those experiences.  And lastly, I have been retired for many years and the meeting gave me the chance to get together with some folks who would now be called on to respond if there was a similar problem today. 


I have found that there are common elements in emergency response of all kinds, whether as part the Red Cross, working with people displaced by Superstorm Sandy; the local fire department, responding to a fire or flood affecting our neighbors; or assisting police deal with a plot by a fanatic armed with radioactive materials and explosives. 


Things you learn in one realm can be applied to the others

TMI units 1 and 2


Unit 1 was down for maintenance. The accident occurred in Unit 2.  Behind it and to the left is the auxiliary building and the vent stack that figure in the accident.


Three Mile Island accident began about 4:00 AM on Wednesday March 28th, 1979.  The plant's main feedwater pump tripped because of a problem while attempting to clear the demineralizers. With no coolant flow in the secondary loop the pressure started to rise on the primary side of the steam generator.  The pilot operated relief valve (PORV) opened to relieve the pressure.  These were normal, planned processes.  None of this was known outside the Unit 2 control room.  Like other DOE responders, I was blissfully ignorant, enjoying the last few hours of sleep I would get in the next 24.

Schematic of a Pressurized Water Reactor

The auxiliary feedwater pumps, containment sump pump, auxiliary building, and the vent stack are significant elements that are not shown in the diagram but come into play as the accident progressed.      


Within the first few minutes one of the control room displays incorrectly showed that the PORV had closed, so coolant continued to flow from the pressurizer. What that display actually showed was that power to the solenoid controlling the valve was off. That would normally cause it to close, but this time there was a mechanical problem causing it to stick in the open position. The pressurizer relief tank overfilled, burst its relief diaphragm, and primary coolant flowed to the containment sump. From there it was pumped out of containment to the auxiliary building where the gaseous fission products were released from the coolant to the building air and then through the vent stack to the environment.

At this point there were lots of alarms going off in the control room, but with no way to prioritize them, the operators were focusing on the wrong ones.

The auxiliary feedwater pumps started automatically but the coolant path was blocked by valves had been closed during routine maintenance and had not been reopened when it was completed.  For the next several hours, operators continued to attempt to control the situation but they did not prevent the core from being partially uncovered, resulting in fuel being damaged.
 That was not recognized until much later.

You now know more about the accident than anyone did that morning. 

At 6:56 AM a Site Area Emergency was declared and Pennsylvania Emergency Management Agency (PEMA) was notified.  They in turn notified Tom Gerusky and Maggie Reilly from the Pennsylvania Bureau of Radiation Protection (BRP), other state and local agencies and the Governor.

Within 15 minutes reactor staff at Metropolitan Edison (Met Ed) called the Brookhaven National Lab Radiological Assistance Program (BNL RAP) hotline and told one of our team captains, Tony Greenhouse, that they had a reading of 600 rads/hr in the auxiliary building. For those who aren't familiar with radiation units that is enough to be life threatening in less than an hour.  They made it clear that they were just informing us not requesting assistance.  Tony called our department chair, Charlie Meinhold, to let him know what was going on. 

The BRP and BNL personnel had known each other for some time.  Charlie Meinhold and Tom Gerusky had been graduate school classmates at the University of Rochester and worked together at BNL before Tom moved to BRP.  Maggie Reilly and I were Atomic Energy Commission (AEC) Fellows under Meinhold at BNL.  Tony Greenhouse had also been an AEC fellow at BNL a couple of years before us.  Tony, Maggie, and I had been part of 6 week long study of environmental and population radiation dose in the Marshall Islands just one year before.

It's Important to know your team well and a trip to the South Pacific isn't a bad way to do it.

From the Marshall Islands trip

Maggie and Tony on the right and I am on the left.


At 7:24AM a General Emergency was declared.  At BNL the RAP Team members were arriving, being briefed, and gathering equipment.  Dave Schweller the head of the Department of Energy, Brookhaven Area Office (DOE BAO) had been told about the RAP call and notified DOE Headquarters at Germantown, MD of a "substantial" problem at TMI and recommended a RAP team response.  Bob Friess, DOE BAO, alerted the Coast Guard requesting helicopter transport to Harrisburg for the BNL RAP team.  Bob Bores, Nuclear Regulatory Commission (NRC) acting duty officer at their King of Prussia office in Pennsylvania and another BNL alumnus we knew from when he worked there called Schweller but did not request RAP assistance.  Again, it was a notification, not a request for response. 

By 8:45 AM the BNL RAP team and equipment were ready to go if requested.  Schweller and Meinhold called Pennsylvania BRP to offer our assistance.  The Coast Guard helicopter stationed on Long Island was out of service so one was in route from Cape Cod.  Meanwhile, at TMI the teams from Met Ed and BRP had found 3 mR/hr off site and an offsite sample from a Met ED team was reported as having a high iodine level.  By 9:00 AM a call from Schweller to Bores at NRC alerted him to the availability of the Aerial Measuring System/Nuclear Emergency Search Team (AMS/NEST) helicopter which could serve as a part of the RAP response or as an independent DOE resource.  At Andrews Air Force Base the AMS/NEST team was readying their helicopter and equipment so that they would be available if needed.  Their initial notification had made its way through many people and by the time it reached them they were told the accident was at Nine Mile Island, a nonexistent reactor, so they collected topographic maps for both Three Mile Island and Nine Mile Point Station just to be sure.

At about 11:00 AM Bores requested the AMS/NEST helicopter for an aerial survey of radiation levels but did not request the BNL RAP team.  A few minutes later Meinhold called Maggie at BRP and again asked if she wanted help.  Possibly concerned because of high iodine reading on the Met Ed sample that had just been reported to them, she said "Alright Charlie, why don't you come on down."  He interpreted that as a request to send the BNL RAP Team.  By early afternoon the BNL RAP team was loading gear and personnel onto the helicopter and more gear and personnel into vehicles.  The AMS/NEST team was doing the same at their base at Andrews.

At this point there were two separate DOE responses being coordinated by DOE HQ in Washington: one was the AMS/NEST team in support of NRC and the other BNL RAP working for Pennsylvania.


The Coast Guard SH-3 Sea King rescue helicopter

On board the helicopter were 5 flight crew, Bob Friess DOE BAO, and 7 BNL RAP health physicists (HPs).  We had radiation survey instruments, the BNL Silver Gel iodine monitor, multichannel analyzers (MCAs), electronics, sodium iodide (NaI) detectors and every reference manual we thought we would need for calculating doses the public might receive. That's me standing near the nose of the helicopter in the second picture.

A second BNL RAP team was getting ready to follow on by van with one health physicist and 3 HP techs carrying more radiation measuring equipment and lead shielding for our counters.

The seating arrangements in the helicopter were utilitarian and limited.  Every seat available was used including the jump seat between the pilots where one of our HPs rode.  He had strict instructions that the controls in front of him included the throttle and he should keep his feet off of them. The rest of us were seated along the sides in the back with no usable windows.  Because of the noise we were all given either headsets, over which we could hear the pilots' communications, or simply hearing protection.

The pilot told us prior to takeoff that we had done everything we could, to overload his helicopter and had come very close to succeeding.  So he would have to get some forward speed before it would have much lift and with the wind direction, that meant heading straight toward the Brookhaven water tower before we rose. 


We made it -- obviously

When we were more than half way to TMI the pilots and our man on the jump seat could see a light plane headed generally toward us.  One of the pilots got on the radio to a controller on the ground and asked them to try to contact that plane and get it out of our flight path.  Radio communication with light planes is not guaranteed, but he was reassured when it changed direction.  Then, for some reason, that plane turned directly toward us.  According to those who could monitor what was said, the pilot used language that was stronger than the usual reserved tones you hear on a commercial flight.  At the same time we banked and dropped about 1000 feet.  For me, not having a headset and therefore having no idea what was going on, it was a lot like a roller coaster ride, but the faces of those across from me who had heard the pilot went white.

As we approached TMI a warning light alerted the pilots to a crack in one of the rotor blades.  This is a situation that requires the pilot land as soon as possible.  But as he was about to pick an interstate median or a farmer's field the light went out.  He figured it was just an instrumentation problem.

The location that the pilot had been told was our destination in Harrisburg was a landing pad at a hospital.  It was designed for much smaller helicopters so he chose not to land there and instead proceeded to the general aviation Harrisburg Capital City Airport about 7 miles upstream of the TMI plant.

When we were on the ground we noticed that the AMS helicopter had also arrived but we did little more than wave to them.  After landing, our first order of business was to survey the helicopter to determine if we had picked up any contamination on our approach.  While clambering around on the helicopter one of our team noticed that each of the rotor blades had a small radioactive source, and there was what appeared to be a Geiger tube on the body of the helicopter.  We asked one of the crew and he told us that each blade is hollow and pressurized with gas, and if a crack develops the pressure bleeds off and the source moves to an unshielded position.  The blade failure light problem was explained!  We had flown close enough to the reactor for the radiation from it to trip the warning light. 

None of us had thought to have an instrument running as we were approaching.  Another lesson we learned that day.

Wednesday evening we set up shop at the BRP offices in Harrisburg.  Most of us went out to try to find the plume or whatever may have been deposited from it.  To figure out where to search, we used a newspaper weather map and flags that we saw as we drove along.  A couple of others of our team set up the multichannel analyzers at BRP and started with dose assessments using measurements and samples that had been collected by BRP and Met Ed staff.  At this time the high sample that had been taken earlier was recounted and no iodine was found.

For the field teams, radio communication was limited to rare instances when we were close to the BRP offices or had favorable geography.  Mostly we relied on finding a pay phone and calling in our measurements of beta and gamma, the number of air, soil, water, and vegetation samples we had collected, and the locations of the measurements and samples.  That worked early in the evening, but many of the phones were inside businesses which closed later that night so we were often getting data that we were unable to report.  Communication from BRP to us would have been useful too if they had been told about a release or change in wind direction.  With what we had that night, it wasn't going to happen.

There were occasions we asked ourselves, "Are we lost?"

It would have been good to know the territory, but we didn't.


Maps of the area

We were using gas station maps similar to the ones shown here.  If we were lucky we would be sampling where all the local roads were shown like on the first map.  But often we were working in areas outside the metropolitan Harrisburg inset map where there was a much lower level of detail so we had to use geographic interpolation, in other words, guess.  Here are a few points on the map that may help to orient you.  BRP was located in the center of Harrisburg a couple of blocks from the river.  Capital City Airport where we landed was across the river to the south east.  Harrisburg International Airport, the area's main airport, and Middletown, where media, NRC, and other agencies would set up their Trailer City on Thursday, are further in the same direction but on the east side of the river.  TMI (shown on the second map) is down river a mile or two to the south east.

About midnight two of us were driving on a back road a few miles from the plant.  We had learned our lesson from the flight and had a Geiger counter running on the seat between us.  It was making the typical background clicks.  Then rather abruptly the counts ramped up until there were so many clicks they sounded like a hiss. That caught our attention.  It didn't hurt that a couple of minutes later a fire siren sounded.  Had a major release occurred and they were trying everything to notify the public to evacuate?  It was unrelated, but we didn't know that at the time so our imaginations ran wild.  We had found the plume.  It was only a few mR/hr but it's not what we expected after several hours of surveying and finding little or nothing.  We got out and connected the Silver Gel sampler that had been developed at Brookhaven about a year before.  This provided its first real test. 


Brookhaven Silver Gel plume sampler NUREG/CR-0314 BNL NUREG_50881

The Silver Gel sampler was designed to capture inorganic and organic iodine by chemically binding it in silver loaded silica gel.  Noble gases had a very low absorption rate on the gel.  This means that the sampling process did a good job of discriminating against them making it easier to measure low iodine concentrations in a mixed plume.  The discrimination was further enhanced by a bismuth screen in the Geiger tube that enhanced its sensitivity to the iodine with respect to the noble gas counts.  It was adaptable with dual motor windings so a simple plug would let it run on either 12V from a car or 120V line voltage. It had a preset 5 CFM flow rate so no adjustments were needed in the field.  All we had to do was sample for 5 minutes and take the sample out of the plume, flush it with uncontaminated air, put the GM probe into the center of the filter cartridge, take a count, peel off the filter paper, take another count, then check background with a clean filter.   With those counts we had a fairly sensitive measure of thyroid dose.  Depending on the time after shutdown, duration of exposure, and the age of the exposed individual, doses of a fraction of a rem to the thyroid could be determined in the field.  Our first sample did not indicate any iodine.  We also collected samples on charcoal filters as a backup. 

After taking samples at a few more locations in the plume we made our way back to the BRH offices in Harrisburg where we counted them using a sodium iodide detector and multichannel analyzer to enhance sensitivity as much as we could

The time was now pushing 4:00 AM.  You probably have never have had the challenge of hand analysis of such a spectra, with lousy statistics in every channel, when the result could influence the state's decision on a major evacuation, all of this while you are significantly sleep deprived.

Our discussion could best be described as interesting.  We then recounted what appeared to be the highest samples for longer and looked again.  We concluded that we had not found iodine in any of the environmental samples.  But based on the noble gas on the charcoal filters we had definitely collected in the plume not just under it.  Our next priority was to find a bed.



AMS/NEST helicopters

Earlier that day we had left the AMS/NEST Andrews team at the Capital City Airport.  They had started making monitoring flights that afternoon and planning for a continuing presence there.  So they found unused offices and work spaces in one of the hangers, had multiple phone lines installed, and set up a command center.  The first picture is the first helicopter dispatched from Andrews.  The second shows the larger one which had been on another mission and arrived later as did still more AMS/NEST staff.  A team from Bettis Atomic Power Lab arrived from Pittsburgh.  They established their base at Capital City Airport with the Andrews group ready to sample and count.



Three members of the BNL RAP sampling team

The second BNL RAP contingent had arrived Wednesday evening. All the teams taking measurements had the problem of distinguishing among several possibilities.  Was there a plume overhead, or were they immersed in the plume, or looking at ground deposition?

Philadelphia Journal front page

On Thursday morning this was one of the front pages that the country was greeted with.  Not exactly what was needed to reassure the public that the only radioactive materials that had been detected outside the plant were noble gases with very low public dose.

Daily News front page and story

Radiation piercing 4 foot thick walls and a nuke plant spewing radiation seems overly dramatic though not as bad as the previous front page.  To add to the public's perception of what was going on, the movie, The China Syndrome had been released just 12 days before.  That movie has a line that the accident that they were dealing with could "contaminate an area the size of Pennsylvania."  It isn't a bad movie if you can avoid getting hung up on some errors in technical details about plant operation.

The New York Times and Philadelphia Inquirer front pages

Not all of the reports were as outrageous.  The New York Times had their story about TMI above the fold, but other stories were given bigger headlines and more prominent placement on the page.  The Philadelphia Inquirer had a less moderate take but not excessively scary.

As with cable news and the internet today you need to pay attention to the source.

On Thursday the teams from Bettis were on scene, teams from Knolls Atomic Power Lab in Schenectady, NY on the way, and more AMS/NEST personnel and equipment coming from Las Vegas, Monitoring was well covered.  So far noble gas but no iodine or cesium had been detected in any of the field samples and the off-site radiation levels were low.  So I, along with the rest of BNL's first RAP team got a chance to catch up on overdue sleep, worked a little more, and then DOE BAO decided we weren't needed, so we headed back to Long Island.  BNL's second team left the area on Friday morning.


Newsday article on Saturday

For more news including what Time and Newsweek magazines reported on the accident and more newspaper front pages CLICK HERE but come back for more of what really happened.

On Friday I was back at BNL with most of the rest of the first team that had been deployed, reloading our kits with fresh Silver Gel sampling media and other supplies that had been depleted.   A reporter from the Long Island paper, Newsday, was there with us while he was waiting for official statements from BNL and DOE BAO to be prepared.  We were not authorized to speak on the record about our response but we took the opportunity to "teach" the reporter about Curies, rads, reactors, and answer general questions while he was waiting for the official news release.  Our explanations seem to have been useful if you look at his later reporting. 

My recommendation is to teach whenever you can.  If you are in some emergency response field and have the opportunity, befriend someone in the media now, so they will have you as a trusted source for background information about some future incident or an explanation of a technical point when they need it.  Many of them will appreciate it.

While we were talking to the reporter and apparently in a light hearted mood we got the word that we were going back to TMI and we got serious.  This time we went by van with counting equipment and 600 pounds of lead brick shielding for our detectors. The reason for our abrupt turnaround and the headline, was that earlier in the day a Met Ed helicopter flight had measured 1200 mRem over the Vent Stack during a planned release.  However, when the report of that measurement reached Washington, the critical information about the location and timing of the reading had been lost.  Somehow it was interpreted as being at ground level in Goldsboro, across the river from TMI.

That would have been nearly 3 orders of magnitude higher than any other ground level reading.  Rather than abiding by the maxim, exceptional claims require exceptional evidence; they immediately went into full over reaction mode!

I would offer a corollary: The further news travels the more verification it requires. That applies equally to its travel from place to place or through organizational levels.

There seems to be an inverse relationship between the distance information travels and its relation to the actual facts.  Inverse Square perhaps?

Later Friday morning concern developed in Washington that there was significant core damage and that a hydrogen bubble had developed in the reactor that contained 1000 cubic feet of hydrogen. One comment from an NRC Washington "expert" was that it was "A failure mode that has never been studied.  It is just unbelievable."

At the report of significant core damage one of my coworkers asked "Could the fuel fall down into a heap at the bottom of the vessel?"
My reply "It would be critical if it fell into a pile", both puns intended.


Should an evacuation be ordered?

At the NRC in Washington, they were basing their decision on the erroneous 1200 mRem reading and various officials recommended evacuation to 10 miles downwind, or 10 miles all around, or maybe just 5 miles.  At the BRP in Harrisburg they had accurate info on that reading and they told Governor Thornburgh that evacuation was not necessary.

NRC Commissioner Hendrie recommended to the Governor a partial evacuation to 5 miles.  President Carter told the Governor "Err on the side of safety and caution."  At his midday press conference the Governor said "Pregnant women and preschool children within 5 miles should leave the area." The exodus began for those specified and many others and continued through the next several days as the press continued to report fears not facts.

A DOE contingency plan was in place in case the situation at the reactor looked like a major release was possible.  An alternate facility had been identified at an Army Post in Carlisle, PA 25 miles upwind.  Our instructions were to grab essential equipment, data, and go.  With teams out collecting samples it was necessary to have a code word that could be put out over the radio net that was now active courtesy of Los Vegas AMS/NEST.  The code for relocation was "Jim Thorpe."  We were told it was because he grew up in Carlisle but we knew that it was really because he had been known as the world's greatest athlete and he could run.

My recommendation to those of you who are planning for your next response "Have plans B, C, and D ready well before you need them."

It was a dark and stormy night.  Actually it was drizzly and foggy but I can't resist the cliche.  It was after midnight and several of us were counting samples that had been collected during the day.  The routine was to count for 7 minutes, use a teletype to print out and punch paper tape for the part of the spectra that would include the iodine peak if any, then look for any indication of an actual peak and recount longer if we saw one, load a new sample and repeat.  We had settled down in our routine when a damsel in distress appeared at our door.

The young lady had been dropped off at the airport planning to pick up a Jeep that her dad had left there earlier in the day.  She intended to use it to evacuate but it wouldn't start and she was scared.  We had a few minutes between samples and she was nearly in tears so there was no question, we were going to help if we could.  Several of us went out, opened the hood while one of us turned the key.  She and the rest of us were looking under the hood and saw a purple blue glow appear over the engine.

She was sure it was radiation!  We recognized that moisture and the ignition wires were the problem.  We pulled them and took them inside to clean and dry them.  Time to change the sample.  Reinstall the wires.  There was an improvement but it was still a long way from running well.  Clean and dry the distributor cap.  Not right yet.  Change the sample again.

Check the ignition wires resistance.  Some are much higher than others.  Change the sample.  The high resistance was traced to the connection at the metal tips on the wires.  Once that was understood all we needed to do was remove the tip, clip a half inch or so off the wire, and replace it.  Changing samples as needed.  All the time we were doing this we were talking to her about what we were doing and what we had found, both with the Jeep and the environment.  When the Jeep was running well we said goodbye and sent her on her way. 

We thought that was the happy ending that we had been working toward but we were in for a surprise.  About two hours later she was back with coffee and donuts for us.  I have no idea where she had to go to get them at that hour of the night but she was now comfortable enough with what was going on to do that for us.

Your actions can speak volumes.


Press corps at Middletown


Saturday NRC, Met Ed, and the world's media are at Middletown, across the river and much closer to TMI than the DOE operation.

The entire DOE operation was at the Capital City Airport.  The press didn't know about us or the scope of our monitoring effort. 

The feeling from all levels of DOE was "Let's keep it that way!"


Map of the area and AMS/NEST resources

The radio net diagram and status board at the command center

By this time AMS/NEST Las Vegas was fully involved with photo and video pods on site.  A radio network with repeaters had been installed; data plots, assignments, and maps were all readily available, as was data from the Atmospheric Release Advisory Center (ARAC) at Livermore.  The data was provided by phone and fax until a remote terminal was delivered and set up.

DOE dose assessment group

The DOE dose assessment group was made up of experts from throughout DOE.  They were using flight and ground survey data, ARAC information, meteorology, State measurements, and TLD stations.  Their work table was a piece of plywood on sawhorses, paper references were scattered about, a handheld radio and phone for communication, and not a computer anywhere to be seen. By this time the analyzed output was going to State, NRC, and Met Ed.

ARAC plot with annotations

          Here is an ARAC plot updated with some of their notations.  Something that strikes me when looking at this plot is that the world is lumpy.  You can't possibly get enough data to model all of that lumpiness.  When pressed, the folks responsible for those models admitted there isn't a good reason to expect that any particular bubble that is shown on this map is actually where the model predicted. However, the maps do provide a good estimate of the scale and magnitude of the variations to be expected.

Dose assessment output

This is one example of the many dose assessments they produced

About 3:00 AM Sunday morning a call came in to the command center.  It was down the hall from where I was working and it kept ringing.  Since I was about the only person available at that hour I answered it

It was from the Whitehouse!

A staffer was preparing a briefing for President Carter prior to his visit scheduled for later that day.  I didn't have the answers needed so I called Andy Hull who by many, was considered to have the best grasp of the total dose picture.  He had the current information that was required and could interpret it for them. 

My takeaway from that was "If you don't know, admit it, and find someone who does."

My usual jobs for the remainder of the response were to collect representative samples starting in the afternoon then package and count them, looking for any iodine, continuing late into the night.  Then prepare a report of what was found for the dose assessment group.  It should be noted that nonstandard samples may be useful.  A sample from a puddle or a ditch by a road may increase detection sensitivity because it has collected from a large area and so can be useful even though you won't be able to use it to compute a population dose.  They can be used to confirm that something more than noble gases is getting out of the plant. 


But those samples are worse than useless if the people doing the analysis don't know how they were collected.

Some environmental samples


Here are some of our vegetation samples in Marinelli beakers labeled and ready for counting.


Sample counting facilities

Our work area was similar to what the dose assessors were using, with our analyzers and teletypes on work benches made from boards and 55 gallon drums or packing crates with teletypes for readout. That's me in the third picture.

Sample collection briefings

Our usual attire when collecting samples didn't let us travel unnoticed.  It was effective in keeping us warm, reasonably dry, and clean but it tended to attract attention when we were out.  On one sample collecting foray, I made a quick stop at my motel to pick up something.  As I was jogging back to the car a small group of people saw me and were sure I was running because of radiation. Seeing their reaction I stopped to explain that I was one of a team that had been there to measure radiation since the first day of the accident, and that we hadn't found anything to be alarmed about.  I also explained that I was rushing because I was late not for any other reason.

Keep in mind that whatever you are doing your actions can be misinterpreted.

State police provided transportation

The Pennsylvania State Police training barracks is located in Hershey not far from TMI so officers were pressed into service as drivers for sample collection.  This had a couple of advantages.  First, they knew the roads so we didn't have to figure out where we were, and second, we could be labeling samples and writing our logs while we were getting to the next location, saving some time. Each sampling team would be given roads to cover.  Every half mile we would collect vegetation and soil samples, take gamma and beta readings, and grab water samples whenever we passed a stream or pond.  While I was doing this my driver noticed that we had someone tailing us.  He would stop when we did, and observe what we were doing.  Obviously a reporter, but this time I wasn't inclined to be helpful.

The officer asked "Do you want to lose him?"

My reply, "YES!"

And we were off on a ride that rivaled the one in the helicopter. You probably already know that you should be careful what you say to an officer.

Brookhaven continuous air sampler

One day my assignment included air sampling.  This time I was using another BNL developed sampler, pictured here.  It was intended to sample at a lower rate for a longer time.  It required 120 V power so several had been set up at fire and police departments, churches, schools, and other public facilities.  For those I just needed to verify the flow rate, change the sample cartridge and record the time. There was one site directly across the river from the plant, south of Goldsboro.  We would sample it occasionally and whenever we had been alerted to a planned release.  Because it wasn't near any public source of power, we would set up a small generator, plug it in and let it run as required.  When I was setting up I noticed two farmers watching from a porch a few hundred feet away, so I went over to talk to them while it ran.  In the course of our discussion I asked them if they weren't concerned since they were so close to the reactor.  One of them replied that based on what I was doing he figured that I probably knew if it was dangerous to be there, and I hadn't left so they didn't see any reason to either.

Again, what you do can be far more important than what you say.

Harrisburg protests

These pictures, taken at a protest in Harrisburg, will give you a sense of the local reaction.  And in Washington outside the church President Carter attended was a sign "Stop the merchants of Atomic Death."  Fortunately I was spared any direct contact with these folks.

Iodine and noble gas pathway to the environment


You may be wondering where the iodine went.  With failed fuel you would expect it to be released.  This diagram shows the principal parts of the path from the core to the environment.  From the fuel elements in the reactor some of the iodine went to the coolant and from there through the PORV (here called the safety valve). The tank intended to catch the coolant overflowed onto the containment floor.  From there some of the coolant was pumped into the auxiliary building.  Some of the gases that had been dissolved in the coolant exchanged with the building air and went up the vent stack.

Core inventory to environment fractions


This diagram is based on a very much later analysis.  It shows the percentage of the inventory of radioactive materials in the core that made it through each of these steps from fuel to the environment. The table below summarizes the fractions.  It is apparent that the tendency of iodine to remain dissolved in the water released from the  reactor vessel prevented a much larger environmental release.  This resulted in much lower public dose than had been assumed prior to that time.



Strontium, Barium



Fraction of the iodine released from the liquid

Noble gases

Core to reactor coolant

< 2





To containment building in the liquid

< 1





To containment building as a gas


< 1




To auxiliary building in liquid phase






To auxiliary building as a gas






To the environment as a gas






Percent of core inventory released to various compartments

Walter Cronkite at the time was known as the most trusted man in America.  His comments over the first three days of the accident:  On Wednesday "The start of a nuclear nightmare."  Thursday "There's more heat than light in the confusion surrounding the incident."  I certainly agree with that one.  On Friday he talked about Prometheus, Frankenstein, and "Tampering with natural forces."

He wasn't helping to calm the public's concern.

Newsweek, Time and more news articles can be found at this link.


Here is a quick summary of things I learned or found useful during my response to TMI:


Know your team well. 

Don't be reluctant to ask for help. 

Prepare for contingencies.  Have plans B, C, and D ready before they are needed. 

Know where you are going both geographically and logically. 

Know and trust your instruments and the resources you have available. 

The media can be your friend, or not. 

Teach whenever you can. 

The further information travels through the organization the more verification is required.

Your actions can be much more important than your words. 

Recognize that you can't get enough data to completely model the world. 

Politics trumps science every time. 

Have staff available to run 24/7 for as long as required.

If you don't know something, admit it, and find someone who does. 

You may be the only one who knows some fact, share it.


The time line and some of the quotes are from "Crisis Contained, The Department of Energy at Three Mile Island, A History, December 1980"
A good book if you can find it.

For more of the news reports including Newsweek and Time's reporting go to

A couple of things you may find useful as training aids when explaining radiation effect to members of the general public.


For a good graphic showing the relative size of radiation doses and their effects:

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