An Introduction to the Disaster

Engineering is an art form that makes use of scientific principle, and this marriage confuses a lot of people.  We tend to think of engineering itself as a science, but it is nothing more than advanced carpentry.   The practitioners learn by doing, and the craft is constantly in a state of evolution.  When the Three Little Pigs built their houses, they all had acceptable designs – acceptable to them – but two of the piggies underestimated the wind loads. (1)

The Three Mile Island accident was not supposed to happen.  Because of the impact that they have on all life within thousands of square miles, nuclear power plants have multiple safety systems, tested designs, knowledgeable operators, and strong oversight.  But what happened in the early morning of Wednesday, March 28, 1979 was not a single failure that can be designed around.  Instead, multiple failures coincided to help cause the worst nuclear disaster in the history of the United States.  Even 32 years removed, its sensationalized accounts have entered our national consciousness as part of the cost of being a nuclear nation.  From the devastation tsunamis wrecked in Japan this past March, we can reflect on both the perils of nuclear energy and the lessons we have learned.

(1) Mike Gray and Ira Rosen, The Warning: Accident at Three Mile Island (New York: W. W. Norton, 1982), 15.

Controversy

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(14)

URGENT (WITH NUCLEAR)

NRC NOW SAYS GAS BUBBLE ATOP THE NUCLEAR REACTOR AT TMI SHOWS SIGNS OF BECOMING EXPLOSIVE

AP Press wire (1)

On Sunday, April 1, 1979, the new headline story was about the potentially explosive gas bubble forming inside the reactor, which prompted even more residents (and even some reporters) to scurry out of the area.  Met-Ed responded by using an industry-accepted but highly controversial method of disbursing it: scrubbing it “clean” (with purifiers which may have been at full capacity before this method), and then releasing the gaseous pressure into the atmosphere.  (2, 3)

Studies in the aftermath of this release have been contradictory: official reports indicate that area residents received no more than 8 millirems of radiation (about the same amount as an X-ray), and persons downwind of the gaseous release no more than 100 millirems (an average yearly dose from background radiation).  (4) 

 However, conflicting studies have shown a marked correlation between the accident at TMI and the rate of cancer, diabetes, leukemia, and other diseases, which has instigated anti-nuclear sentiments in the decades following the accident. (5)

(15)

Even scientists are skeptical of the efficacy of nuclear power with respect to the dangers that such power has.  Conclusions from the N.R.C.’s official reports show that the prevention of the plant’s meltdown was due to inadvertent actions by the operators – the same operators whose actions also put the core in danger. (6) Regulation up to the point had been sparse – there was no standard for control room layout, emergency procedures or practice with alerting civilian defense.   The N.R.C. has been accused by the very industry it is supposed to regulate as “not knowing ‘sophomore nuclear engineering,’” and continually failing to keep up with developments at TMI during the accident. (7)

There never was a very close correlation between what was happening to the reactor and what the N.R.C. though was happening.

-          Commissioner Bradford (8)

If the operators had simply stopped acting once they realized they had been working under faulty instruments and were essentially “flying blind,” the Unit 2’s core would have melted down within 20 minutes.  It would have been self-contained in a ball of melted glass (the bedrock), over 100 feet into the ground.  Some experts believed that this timely burial would have been preferable to having to clean up surface radioactivity and transporting the waste across the country to safe facilities. (9)

In the aftermath, the N.R.C. came under fire by both presidential and congressional commissions and has significantly changed regulation procedures.  (10)  However, in 1979 alone, 11 nuclear plant plans were scrapped and largely replaced by coal plants.  (11)

(16)

The legacy of the TMI accident is that the United States has not realized its nuclear potential: from 1981 to 1984 alone, 51 nuclear stations were scrapped. (12)

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Citations:

(1) Mike Gray and Ira Rosen, The Warning: Accident at Three Mile Island (New York: W. W. Norton, 1982), 243.

(2) Mark Stephens, Three Mile Island (New York: Random House, 1980), 214.

(3) Daniel F. Ford, Three Mile Island: Thirty Minutes to Meltdown (New York: Viking Press, 1981), 248.

(4) William Keisling, Three Mile Island: Turning Point (Redmond, Washington: Express Publications, 1980), 148.

(5) Stephens, 228.

(6) Ford, 253.

(7) Ford, 248.

(8) Ford, 250.

(9) Stephens, 228.

(10) Gray, 270.

(11) Stephens, 230.

(12) Cancelled Nuclear Units Ordered in the United States. [online] Accessed on April 21, 2011.  http://clonemaster.homestead.com/files/cancel.htm

(13) Keisling, 44.

(14) Gray and Rosen, 155.

(15) Robert Del Tredici, The People of Three Mile Island (San Francisco: Sierra Club Books, 1980), 46.

(16) Keisling, 26.

(17) Del Tredici, 5.

The Media

“I thought I was going to get mugged.”

-- Mayor Bob Reid, after a Thursday press event (10)

(11)

The world has never known a day quite like today” (1)

Over 200 reporters paced outside the walls of the plant by Wednesday afternoon.  The one public payphone became inoperable by lunchtime because it was overfilled with change. (2)  The network news was still optimistic in light of Med-Ed’s reports.  However, the N.R.C. was starting to doubt the company line and unofficial members spoke of that concern with the press. (3)

Trying to determine if the climax of the story had passed or not, the Philadelphia Inquirer sent the largest crew of 30 to get a good measure of the incident. (4) Throughout the night, teams of reporters continued to pour into Middleton, unaware that the reactor crisis was merely the beginning of the disaster.

YouTube vidreo of ABC News coverage on March 28, 1979

Scrambling for a Lead

Met-Ed employees were reluctant to talk about the incident to the press and thought that the reporters were already making more of the mishap than needed.  Met-Ed would not release a list of employees to the media, so reporters for the Inquirer wrote down the license number of all cars going into or leaving the plant and got the Bureau of Motor Vehicles to release names and addresses.  Inquirer reporters offered anonymity to any worker willing to speak and soon got the inside scoop on the long hours and high exposure to risk that was not being made public. (5)

More so than anything, reporters were upset that there was no network in place for information gathering.  NASA had provided experts to explain technicalities, and the N.R.C. was nearly as secretive as Met-Ed. (6)

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WKBO

On Thursday, WKBO aired the viewpoints of Dr. Ernest Sternglass, a professed antinuclear activist, which helped usher residents out of the town overnight.  “The reaction of the community should be to stand up and scream. […] I’m particularly concern with the possibility of an increased risk of leukemia and cancer among the very young.  The newborn and the infant in the mother’s womb are ten to a hundred times more sensitive than the average adult … pregnant women should very seriously consider leaving.” (7)

WHP

On Friday, Kevin Molloy, a civil defense servant, jumped the gun and announced to the community via the radio station WHP that there would likely be an evacuation.  With this tacit confirmation, thousands of local citizens left, cashing out their bank accounts and even buying cars from a salesman with hard currency.  More than 137, 00 phone calls were made in Harrisburg, which so jammed up the lines that it took 10 to 15 minutes to even get a dial tone. (8)

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Reaction to Media Coverage

In the aftermath of the accident, no one party has been criticized more than the media.  Charged with sensationalizing the disaster out of proportion, crowds of reporters roamed the streets Middleton in search of stories.   They found them where they could: they interviewed residents, hounded employees, chased after officials, and even started interviewing each other. 

The CBS lead correspondent, Richard Wagner, was critical of the media’s coverage of TMI:

 “They gave the impression that Armageddon was at hand.  It was Walter’s tone that particularly gave this impression…” (9)

-

(1) Mark Stephens, Three Mile Island (New York: Random House, 1980), 4.

(2) Ibid, 87-88.

(3) Ibid, 107-8, 119-20.

(4) Ibid, 103.

(5) Ibid, 145-6.

(6) Ibid, 148.

(7) Ibid, 130.

(8) Ibid, 162. 

(9) Ibid, 187.

(10) Ibid, 124.

(11) Mike Gray and Ira Rosen, The Warning: Accident at Three Mile Island (New York: W. W. Norton, 1982), 248-9.

The China Syndrome Effect

The China Syndrome (1979) opened on March 16, twelves days before the TMI event, and is almost a prescient view of the disaster.  Starring Jane Fonda, Jack Lemmon and Micheal Douglas, its sensational treatment of a possible nuclear meltdown had lines wrapped around theater’s blocks.  In response to this, reporters all over the country were reaching for magazines whose covers were graced with Fonda’s image as source material.

What was intended as a warning of disaster had become a briefing film for the press.  At a major newspaper the assignment editor waves the wire copy an shouts for attention.  “How many of you guys have seen The China Syndrome?”

Three reporters raise their hands.

“You, you, and you.  You’re going to Harrisburg.” (1)

(1) Mike Gray and Ira Rosen, The Warning: Accident at Three Mile Island (New York: W. W. Norton, 1982), 142.

Immediate Response

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Emergency

At 6:56 a.m., nearly three hours after the initial incident, the TMI supervisor declares a site emergency, which is soon followed by an official “general emergency.”  There is confusion even among law enforcement in nearby Harrisburg of what that even means.  Reports coming out of the TMI plant are unintelligible and infrequent, and what little information that comes out is patently soothing.  Met-Ed eventually contacts the civil defense state and local agencies.  By 8:40 a.m., a van of N.R.C. officials (none of whom have enough familiarity to operate the TMI-2 reactor) leaves Philadelphia. (1)

Met-Ed’s representatives and the officials kept reiterating how little there was to worry about and how there was “a cause for concern but not alarm.” (2)  Soon, an advisory evacuation was recommended for children and pregnant women.

By this time, scattered reports of emergency had reached the media.  Scores of reporters have flocked onto the island even as some nervous residents headed out of town.

(1) Daniel F. Ford, Three Mile Island: Thirty Minutes to Meltdown (New York: Viking Press, 1981), 35-36.

(2) J. Samuel Walker, Three Mile Island: A Nuclear Crisis in Historical Prespective (Berkley: University of California Press, 2004), 89.

(3) Mike Gray and Ira Rosen, The Warning: Accident at Three Mile Island (New York: W. W. Norton, 1982), 248.

The Accident

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March 28, 1979: just before 4 a.m.

In a routine matter, operators sealed off tank 7 of Unit 2 to flush out the BB-size balls of resin that clean the water that is used in the cooling system before it is sent back to the reactor.  As usual, the resin balls stick together in the output.  Initially, the jerry-rigged tactic of fluffing the balls with a shots of high-pressure air does not work.  The resin constipates the pipes, until  finally the honey-consistency sludge beaks free.  (1)  Unnoticed to the workers, a small amount of water leaked in around a valve from the built-up pressure in the pipes during the clog, and traveled through the pneumatic pipes that service the varied systems.  As a safety precaution, these controls trip (or close) automatically if they lose air pressure or if something (like a little water) get in the way. (2)  

Information Overload

At 4:00:37 a.m., hundreds of white alarm lights blink in the control room and the printer starts chattering away with error codes. 

http://en.wikipedia.org/wiki/File:Tmi-2_schematic.svg

Stuck Valve

Unit 2’s electricity-generating turbine has tripped (or shut down), and two secondary feedwater flow valves have also tripped.

In normal operation, the heat produced by the nuclear core’s reaction is carried by the closed-loop primary feedwater system to steam generators that convert that heat to produce steam supplied by the secondary feedwater system.  If the secondary feedwater system no longer can convert into steam and run the turbine, the closed primary system overheats rapidly.  A pressure relief valve is designed to open in such an occasion and release the superheated water in a waste tank.

(8)

Within 15 seconds of the initial incident, control rods slip into the uranium core to stop the nuclear reaction, but this “scramming” does not remove the residual heat from the primary loop.  Auxilliary pumps are designed automatically activate and pump emergency water into the primary loop, but recent routine maintenance had left them closed and unresponsive. (3)   Foolishly, the design of valve indicators does not show whether the valve is open or not, but rather if the computer has given the valve a command. (4)  Unbeknownst to the operators in the control room, four failures are converging: auxiliary valves that will not open, a pressure relief valve that will not close, a faulty pressure-reading gauge in the steam generator, and no useful knowledge about the true conditions in the core.

The two valve switches (left top and bottom), which control the emergency feedwater flow, were found closed. (9)

Reacting to faulty assumptions and ignoring unexpected readings, the operators turn off the emergency flow to the primary system, believing that the system is equalizing.  However, the pressure relief valve is still open and the replacement water is draining away, leaving very little left.

The reactor’s water is boiling off!

Ten minutes after the initial warnings, the faulty reader in the steam generator finally indicates that there is not enough pressure for normal operation and the workers reengage the emergency pumps to the core, but the water continues to drain through the pressure relief valve into the storage waste tank.

Overflow

Fifteen minutes into the mishap, the waste storage tank is full.  Not designed to hold so much water, a disc blows out of the side and a sump pump drains the radioactive water into an auxiliary building.  That, too, overflows and is about to be released into the atmosphere. (5)

Isotope iodine molecules react with silver in the control rods, and hydrogen bubbles begin to form in the core’s cooling channels, choking off flow.  

The temperature steadily rises….

If it hits 5000 degrees, the core will melt through the floor of the plant, the eight-inch thick steel pressure vessel, the twenty-foot concrete foundation, and maybe even the bedrock of the Susquehanna River. (6)

(1) Mike Gray and Ira Rosen, The Warning: Accident at Three Mile Island (New York: W. W. Norton, 1982), 73.

(2) Mark Stephens, Three Mile Island (New York: Random House, 1980), 9.

(3) William Keisling, Three Mile Island: Turning Point (Redmond, Washington: Express Publications, 1980), 20-21.

(4) Ibid, 27.

(5) Ibid, 22.

(6) Gray and Rosen, Warning, 101.

(7) Ibid, 78.

(8) Keisling, Turning Point, 119.

(9) Ibid, 20.

Location

(4)

The Site

Three Mile Island (TMI) lies ten miles southeast of Harrisburg, Pennsylvania’s state capital.  The Susquehanna River flows around several large islands, and TMI is located less than 900 feet from the east bank and 1.5 miles from the west.  Before the General Public Utilities Corporation (G.P.U.) announced in 1966 that it would use the site for a commercial nuclear power station, TMI was a fertile 400-acre leased plot of farmland.   

(5)

Ironically, TMI’s energy would be superfluous in the heart of coal country, but its easy access to water, centralized distribution location, firm bedrock, and inexpensive local labor made it an potential site. (1)

G.P.U. had planned to add a second unit to its Oyster Creek, New Jersey facility, but local labor problems necessitated that the second unit be added to the new construction at TMI as Unit 2.  The plant at TMI would be operated by G.P.U.’s subsidiary, Metropolitan Edison (Met-Ed).  The Atomic Energy Commission (A.E.C.) approved permits for the construction of both units by the end of 1969 with minimal oversight over this “self-regulating” company; the Atomic Energy Act of 1954 made the A.E.C.’s function not only regulation, but also promotion of the new nuclear energy industry. (2)  The TMI location would be just one of several Babcock & Wilson designed nuclear steam-driven plants.

“Good Enough” (3)

Unit 1 was complete in 1974 and began operating under an A.E.C license, despite the A.E.C.’s discovery of honeycombs (or air bubbles) that had formed in the foundations.  By the time Unit 2 was completed in 1978, the Nuclear Regulatory Commission, who had flagged 14 “open safety items” during its license inspection of Unit 2, had replaced the A.E.C.  One of these flagged concerns dealt with the ability for the plant to control small loss-of-coolant (LOS) accidents, which could be caused by a stuck-open relief valve. 

However, Unit 2 was declared operational and commercially viable by December 30, 1978, just in time for a tax credit.  As a cost cutting measure (and a wide-spread tactic), the majority of the reactor’s operators would not be trained nuclear scientists, but rather trained employees with a single expert overseer.

They were probably still better employees than Homer Simpson

Citations:

(1)  William Keisling, Three Mile Island: Turning Point (Redmond, Washington: Express Publications, 1980), 54.

(2) Daniel F. Ford, Three Mile Island: Thirty Minutes to Meltdown (New York: Viking Press, 1981), 35-36.

(3) Keisling, Turning Point, 83.

(4) Ibid, 18.
(5) Robert Del Tredici, The People of Three Mile Island (San Francisco: Sierra Club Books, 1980), 84.

Introduction

Engineering is an art form that makes use of scientific principle, and this marriage confuses a lot of people.  We tend to think of engineering itself as a science, but it is nothing more than advanced carpentry.   The practitioners learn by doing, and the craft is constantly in a state of evolution.  When the Three Little Pigs built their houses, they all had acceptable designs – acceptable to them – but two of the piggies underestimated the wind loads. (1)

The Three Mile Island accident was not supposed to happen.  Because of the impact that they have on all life within thousands of square miles, nuclear power plants have multiple safety systems, tested designs, knowledgeable operators, and strong oversight.  But what happened in the early morning of Wednesday, March 28, 1979 was not a single failure that can be designed around.  Instead, multiple failures coincided to help cause the worst nuclear disaster in the history of the United States.  Even 32 years removed, its sensationalized accounts have entered our national consciousness as part of the cost of being a nuclear nation.  From the devastation tsunamis wrecked in Japan this past March, we can reflect on both the perils of nuclear energy and the lessons we have learned.

(1) Mike Gray and Ira Rosen, The Warning: Accident at Three Mile Island (New York: W. W. Norton, 1982), 15.