The Three Mile Island Nuclear Plant – An Update on the 35th Anniversary

Neil Sheehan
Public Affairs Officer
Region I
The Three Mile Island Unit 2 Control Room bustles during the crisis in 1979. For more historical information, click on the photo to go to the NRC YouTube video about the accident.
The Three Mile Island Unit 2 Control Room bustles during the crisis in 1979. For more historical information, click on the photo to go to the NRC YouTube video about the accident.

Today marks 35 years since the accident at the Three Mile Island 2 nuclear power plant. As is the case every year, it represents another opportunity to reflect on the most significant nuclear power plant accident to ever occur in the U.S.

Perhaps less well known to the average citizen is where things stand in terms of the Middletown, Pa., site all these years later.

GPU Nuclear, which owned the plant at the time of the accident, removed the damaged fuel from the reactor and decontaminated the plant in ensuing years. Once the plant was placed in a safe, stable condition, it transitioned to what is known as “post-defueled monitored storage” — a change that was formally approved by the NRC in 1993.

Last year, the current owner, FirstEnergy, submitted a roadmap to the agency on its plans for eventual dismantling the plant. Those details were contained in a document called a Post-Shutdown Decommissioning Activities Report, or PSDAR.

In short, the plant will remain in storage until its neighboring reactor, Three Mile Island 1, permanently ceases operations, something currently expected to happen in 2034. Once that happens, decommissioning work on both units will be undertaken, but those efforts are projected to take many years.

NRC regulations allow up to 60 years for the completion of decommissioning activities for U.S. nuclear power plants.

A view of the TMI-2 control room, last year, with two NRC inspectors.
A view of the TMI-2 control room, last year, with two NRC inspectors.

Meanwhile, the NRC will continue to inspect TMI-2 at regular intervals. The focus of those reviews includes maintenance of the structures, management oversight, fire protection and plant support activities. The results of those inspections can be found in the NRC’s electronic documents system.

While another anniversary has arrived for TMI, the work on keeping close watch on the plant goes on, and will continue for many years to come.

Author: Moderator

Public Affairs Officer for the U.S. Nuclear Regulatory Commission

27 thoughts on “The Three Mile Island Nuclear Plant – An Update on the 35th Anniversary”

  1. The sarcastic side – Mr. Williams, because you are brilliant and most are ignorant, according to you, please see the above post directed to Mr. Adams. Y’all have many thoughts in common and everyone else are just country bumpkins awaiting for y’alls superior intellect to enlighten us to the benefits of nuclear weapons and the cost benefits of nuclear power. Of course the millions of pounds of spent nuclear fuel is perfectly safe, and the many years of education and military involvement I experienced means absolutely nothing. That is my sarcastic reply to you.

    Reality – It is folks such as you which are scary as you pretend to have answers which are not reality. Like others in the nuclear industry your attitude becomes dangerous when applied to the problems we as a nation face regarding costs, nuclear waste, nuclear risks and a decaying and antiquated nuclear power infra-structure.

    We got nuclear problems.

    Moderator note: some verbiage removed to adhere to blog guidelines

  2. A bit of a sarcastic reply.

    Of course Mr. Adams, “radiation” is very safe, that is the reason the immediate areas surrounding the Fukushima nuclear disaster are safe, the workers should not wear protective gear when cleaning up the contamination. Dr. Karl Morgan did not know what he was talking about concerning Health Physics because he did not have you to instruct him. Of course, the lessons learned from nuclear disasters are not real and are all plots of the infamous Rockefellers.

    Maybe the “radiation” surrounding the Fukushima plant site it is not contamination, maybe it is a health benefit, Hormesis Theory – probably a secret part of Obama Care. Since you maintain that we are living in a 1950’s radiation protective environment and and the Rockefeller Foundation is the cause of your and the nuclear industry’s problems, why not go to the contaminated areas surrounding the Fukushima plant site and roll around in the contaminants along with drinking and bathing in all that fresh, contained contaminated water. Surely you will be healed, live a long life and you will be able to say, “See I was right, and everyone else supporting increased risk analysis, caution and safety regarding ionizing radiation are pawns of the Rockefellers.” Or, reality might set in and you might ask after your Radiation Hormesis trip to Japan, ” Why do I not fell well?”

  3. Each time I read the passionate though misguided comments typlified by many of the above, I am struck by just how technoligically and scientifically illiterate this country has become. This is unfortunately equally as evident among our representatives in the Congress. I have worked around radiation and in the nuclear industry for 48 years and the scariest thing to me, is not radiation, it is someone who has spent a few hours on google and who now knows everything. My kids used to know everything when in their teens but they grew up.

  4. @stock

    You are operating with a 1950s vintage understanding of radiation health effects. That is not totally your fault; there are many interested parties that have worked hard to prevent the improved understanding that would enable people to lose their carefully taught fear of radiation.

    In the mid 1950s a group of geneticists – people who did not understand the structure of DNA and had no way of detecting changes or ordinary processes occurring there – were brought together by the National Academy of Sciences at the specific request of the board of trustees for the Rockefeller Foundation. Those geneticists, at least half of whom had been grantees of the Rockefeller Foundation, formed a committee chaired by Warren Weaver, the director of the natural sciences program at the Rockefeller Foundation.

    Weaver held the grant checkbook that enabled these geneticists to perform their research and maintain their rather expensive laboratory facilities.

    Surprise, surprise, the committee issued a unanimously approved report that contradicted all existing science and understanding of radiation health effects by declaring that there was NO SAFE DOSE and that doses down to a single ionizing radiation track through a living body had the potential for causing an inheritable mutation.

    The petroleum and coal interests in the Rockefeller Foundation endowment could not possibly have had anything to do with the declaration that radiation was not safe and that the public should be quite worried about unseen effects caused by building and operating nuclear power plants. Coincidentally, that report was issued in 1956, the year that the first commercial nuclear electricity generating facility began operating in Great Britain and the year before the Shippingport reactor, the first one in the US, began commercial operations.

    Rod Adams
    Publisher, Atomic Insights

  5. 35 years since the NRC, President Carter, the PA governor at the time, and nearly everyone involved in government or in the industry, proved once again, that when it comes to nuclear power, compulsive lying is automatic, and hundreds of thousands of people have their lives made miserable and cut short by cancer, heart disease, diabetes, you name it, from ionizing radiation and nuclear isotope pollution, both from ‘accidents’ and from routine emissions. How many kids were born deformed? How much did this accelerate genetic load? How many mutations were added to the human genome which are unexpressed and invisible? You all go eat a case of chocolate bars now.

  6. Not only backsides but look at the number of folks in the Control Room. Total lack of control of Control Room access. Most of these folks had no real business being in the CR! Most of these folks were regulatory rubberneckers. Sad picture in more than one respect!

  7. When you are blowing up cells and DNA, it is pretty clear what the results are, and there is plenty of scientific evidence that does show that low dose does cause diseases and cancers. Hormesis is a lie.

    How much “extra” radiation are you trying to put into your body to get those positive effects? Maybe I am wrong, maybe you are pursuing extra radiation, if so, please explain your regimen of extra radiation.

    Moderator: Some content removed to adhere to the comment guidelines.

  8. I agree, I want to see the NRC instigating strong financial penalties, which are the ONLY way to get the attention of a Corporation.

  9. Lest We Forget – The NRC played a role in causing the accident at TMI
    I am glad the NRC is reflecting on the accident at Three Mile Island. As we reflect we must take a look at our roles leading up to and during the accident.
    The NRC has done a masterful job of pointing out the shortcomings of the industry they regulate. It is human nature I think for us to find it easier to point the finger at others rather than at ourselves. The NRC, to this very day, has not adequately pointed the finger at themselves for contributing to this accident. They have conveniently failed to mention their role in this tragedy. Inadequate reactor operator training was one of the root causes of the accident. And of course we know that the NRC is responsible for the licensing and the training of every single licensed reactor operator. More than this, the NRC’s culpability goes much deeper.
    For years prior to the TMI accident the NRC created and perpetuated a dangerous operator mind-set. They mandated extensive training and annual re-training for all reactor operators at all nuclear power plants that emphasized the dangers of overfilling the reactor cooling system. The NRC training focused on preventing the reactor cooling system from becoming overfilled and over pressurized. They wanted operators to prevent the reactor cooling system from “going solid” at any cost.
    The NRC did not want system pressure relief valves to be actuated causing a Loss of Coolant Accident (LOCA). While this sounds like a good thing, it lead operators to do exactly the wrong thing during their response to the TMI accident. Let me try and explain.
    Once the normal heat removal capability of the reactor cooling system failed, the reactor and the reactor cooling system heated up causing the level in the pressurizer (a surge tank connected to the coolant system and located at a position above the reactor) to increase and the pressure in the cooling system to increase. The pressure reached the point where a pressure-relief valve automatically lifted as designed to relieve the over pressure. Unknown to the operators the relief valve failed to re-close when pressure was reduced causing an on-going LOCA. As precious reactor cooling fluid was being lost from the system, automatic fluid makeup systems cut in, actuated by the low system pressure. These makeup systems were doing exactly what they were designed to do – keep the fuel in the reactor covered and cooled with water. If these makeup systems had been allowed to continue operation the reactor fuel would never have melted and the TMI accident would not have occurred. However, the NRC-perpetuated operator mind-set to avoid overfilling the coolant system, resulted in operator action that overrode the automatic response by throttling and then securing this vital makeup flow. The NRC inappropriately stressed, in the operator training program, only one aspect of safety at the expense of the big picture, that is, keeping the reactor covered and cooled with water. This negative training directly lead to operator error that caused the accident.
    To their credit the NRC made improvements to their regulatory process after TMI, but to my knowledge they have never fessed up to messing up the reactor operator-training program. And that is inexcusable.

  10. Actually, the Fukushima meltdowns would have been greatly reduced in magnitude, and the hydrogen explosions prevented, if Naoto Kan had not demanded that the reactor operators delay the venting of the Unit 1 containment for several hours (needed in order to add water).  For some reason, his scheduled press conference took priority over halting the progress of fuel damage.

  11. Point well made sir. Proper safety engineering costs money, money the civilian nuclear industry has not been willing to expend. Unfortunately the NRC at times seems more supportive of the nuclear industries bottom line instead of the health, safety and welfare of the public.

  12. Amusing? There is nothing amusing about the deceit perpetrated on the American people by the nuclear industry and their cadre of multi-million dollar law firms and PR propagandists. Reminds folks of the tobacco campaigns of the 20th century, cigarette smoking is good for you. The same propaganda is being facilitated by the nuclear industry.

    Three mile Island, Chernobyl, Fukushima should have been a wake up call demonstrating nuclear power is deadly, dangerous and expansive. Instead, the nuclear industry floods the media with propaganda and deceit to protect their bottom line. Nuclear power is a classical example of money being placed before ethics, morals and sometimes the law.

  13. Could you not find a better picture of the 3 mile Island control room in 1979? I would rather not look at everybody’s backside.

  14. The term “ex-vessel” is key to understanding how an autonomous water-level instrumentation system can – and should — be installed in both BWRs and PWRs. As indicated in an expired 1987 patent, high-energy gamma-ray detectors located outside the pressure vessel (but inside the containment shield) have been shown to be quite sensitive to water-level changes inside the reactor.

    “Autonomous” in this case means that the system would (1) function independently of in-core instruments, (2) have its own power and electronics, and (3) be shielded by the intervening pressure vessel from other influences.

    There is a reasonably substantial publication record, based initially on experiments at the TREAT test reactor in Idaho, with confirmation derived from the LOFT experiment series, and with computational agreement published by French CEA scientists.

    Because Fukushima meltdowns occurred without reactor operators being aware of impending or ongoing loss-of-coolant, those accidents serve to remind the nuclear community that all water-cooled reactors would be well served by cost-effective installation of autonomous instrumentation.

    –Alex DeVolpi

  15. Part of Dr. John Gofman’s forward in the book “Poisoned Power,” a case against nuclear power before and after the Three Mile Island disaster. Unfortunately the book, “Poisoned Power,” did not stop the insanity. Redistribution is encouraged:

    Short Bio – Dr. John William Gofman (September 21, 1918 – August 15, 2007) was an American scientist and advocate. He was Professor Emeritus of Molecular and Cell Biology at University of California at Berkeley. Some of his early work was on the Manhattan Project, and he shares patents on the fissionability of uranium-233 as well as on early processes for separating plutonium from fission products. (Wiki)

    Excerpt and Summary: “An ethical society, concerned with preserving the inalienable right to life, would learn all the steps in such pathways before ever permitting activities which could release the radioactive poisons upon the public. An uncertainty factor of 1,000 is a horrible uncertainty to have about the dose a human infant will receive. Experimentation on people by the nuclear industry must be stopped, and the industry’s disdain for people’s health—its “Expose first, learn later” philosophy—must be exposed for its moral bankruptcy.”

    “The risks from irradiation are cumulative. A small dose will give you a small risk. But another small dose will give you an additional small risk. By now, the nuclear industry must have announced 100,000 “small” releases of radioactivity into the environment. It is the only industry which can add 100,000 “small” releases to each other, and still say the sum is small and the harm to the public is zero!”

    “There has been much press and TV coverage devoted to the technical aspects of the Three Mile Island accident, but very little to its moral aspects. Yet the really important questions about nuclear power are ethical:
    •The use of lies and deception by the nuclear industry in order to manipulate public opinion, and in order to use people, even kill people, for the benefit of that industry.
    •The experimentation on people without their knowledge or consent.
    •The acceptance of random murder and denial of the inalienable right to life as the cost of “progress.”
    •The genetic degradation of the human species, vs. our minimum responsibility to protect our species’ genes from injury.
    •The need to hold bureaucrats and industry employees personally accountable and responsible for implementing hazardous and even murderous policies, even if such policies are advocated by Congress and the President.”

    “Yes, Poisoned Power is a sad story about the absence of ethics and morals in men. But it is not too late to jolt society into realization of what is going on, and what is in the future if humans do not improve in the very basic and minimum principles of morality. Either we improve, or the future is dismal indeed. We hope that Poisoned Power upsets you enough to make you work toward such improvement.”

  16. We understand “greenfield” to mean that all industrial buildings have been removed and the site has been released for unrestricted use. Five former reactor sites meet both criteria. Another eight that have been released for unrestricted use still have buildings on the sites.

    Maureen Conley

  17. I would like to respond to the comments of Dr. DeVolpi and nspunx4:
    I don’t understand what is meant by “ex-vessel autonomous ex-vessel water-level instrumentation.” Aside from the redundancy, ex-vessel water level is measured in many locations – Pressurizer, Refueling Water Storage Tank, Containment Recirculation Sump, etc. None of these had anything to do with the TMI-2 accident. The term “autonomous” doesn’t make sense in this context. Perhaps you mean “self-powered,” “safety-grade” or “redundant.” Probably, what is meant is “Reactor Vessel Level Indication System,” commonly referred to by the acronym RVLIS.

    Yes, we realize that the primary loop in a PWR is completely filled with water – during NORMAL operation. We propose to measure the water level in a closed, high-pressure system during ACCIDENT conditions, when it is certainly possible to have a steam bubble in the reactor vessel. This was exactly the problem at TMI-2. The thermodynamics of the event produced a large steam void in the reactor coolant system while pressurizer level was excessively high. If the operators at TMI-2 had had a RVLIS system, they might not have taken the improper actions that uncovered the core and caused severe fuel damage.

    The discussion of the Fukushima accident is not germain to PWRs. These were BWR type plants, which have always had multiple indications of reactor vessel water level. The problem at Fukushima was that these instruments lost electrical power supply and became inoperable. Perhaps this is why Dr. DeVolpi used the term “autonomous” (meaning self-powered?). I can not comment on this possibility because I am not aware of any such instrumentation.

    With respect to PWRs, all commercial PWR power plants in the US have now installed redundant, safety-grade RVLIS instrumentation. This was one of the post-TMI accident requirements, and was completed long before the Fukushima event.

    Donald M. Scheef

  18. Um… You do realize that the primary loop in a pwr is completely filled with water except for the steam space in the pressurizer? How do you propose to measure water level in a closed high pressure “solid” (except for the steam space in the pressurizer) system?

    Oh yeah… You measure the level in the one place that has a “level” the pressurizer.

  19. Growing up north of TMI (in Shamokin, PA) and having immediate family living in Middletown & Lancaster, PA at the time of the accident, I still have vivid memories of the differences in the news reporting and the public perception of the accident as portrayed in local and national news broadcasts. The local news coverage stemmed more from curiosity over the fact that all the local TV & radio stations, as well as the local newspapers, were notified that there would be a major press conference at what was then a fairly new power plant (Unit 1 had produced power for maybe 2 years, Unit 2, just under a year).

    The overall tone of the local news reports was that while there was cause for concern about what was happening at Unit 2, engineers and plant operators were on top of everything. (Our neighbors were doing there best to address the situation and would keep us informed on what was happening.) This overall tone did not change throughout their coverage of the events. The local media appeared to be genuinely interested in getting answers out to the public. As a result, the local coverage focused on what State and NRC officials were actually trying to tell the public rather than going for sound bites. (Maybe that was because the local press liked covering Dick Thornburg & Lt. Governor Bill Scranton, or that they found the NRC’s spokesman, Harold Denton, to be “folksy” or the fact that one of the NRC’s other technical leads was Vic Stello, who was essentially a “local boy” having grown-up in Kulpmont, PA and earning his engineering degree at Bucknell University in neighboring Lewisburg, PA.)

    The tone of the national news was another story: ALL OF PENNSYLVANIA WAS IN DANGER and we should think about evacuating Maryland, New Jersey and Washington DC just to be on the safe side! I don’t think anyone in my family or among my high school friends believed or were afraid that there was any real danger from the plant until Governor Thornburg ordered the evacuation of pregnant women and small children from the immediate area. (I don’t blame the Governor for that. Considering how confusing communications had become at the plant, it was better to conduct a likely unnecessary evacuation, if only to give the swarm of newsies something to report away from the plant itself. The operators, engineers and NRC investigators at the site could focus on resolving the problem with fewer distractions.) Even after this, while people were definitely worried, I didn’t see signs of panic. I think people believed the local news reports and figured that as long as they were willing to remain at TMI to report the news, the rest of us were still safe.

    My resentment of the national news exploiting what was a potentially dangerous situation to assure a ‘vivid story’ (and great TV ratings) rather than providing an accurate account of what was happening was a major factor when I pursued a college degree and a career in nuclear power.

    While TMI put the anti-nuke power movement into high gear within the United States, I found it amusing that in the years immediately following the accident, the greater concern in the Harrisburg area always appeared to be that the accident would depress local real estate values rather than actually hurt anyone. While there were subsequent local protests at TMI and at (relatively) nearby new power plant construction at Susquehanna (Berwick, PA) and Limerick (Pottstown, PA), the movement failed to prevent the restart of TMI-1 or the start-up of 4 new nuclear power plants all within a 2-hours’ drive of TMI. (That protestors sometimes showed up at the Montour Power Station, a coal-fired plant with cooling towers not all that far from the Susquehanna plants, to protest nuclear power was out-right comical.)

  20. Your statement is a blind assertion. It is not supported by any research. There is no reliable evidence that low level exposure to radiation has any negative effect on organisms and there is a fair body of evidence that it actually has a positive effect.

  21. Although NRC Public Affairs celebrates TMI-2 accident closure, some major lessons that should have been learned have never been implemented. Three Fukushima meltdowns have accentuated these same shortcomings.

    The TMI accident was preventable if ex-vessel autonomous ex-vessel water-level instrumentation had been previously installed. Moreover, one or two Fukushima loss-of-coolant meltdowns might have been forestalled or prevented if such instrumentation had been introduced as a consequence of the TMI tragedy.

    It took about five years before it was possible to characterize fuel relocation after the TMI accident; it might take even longer at Fukushima. If ex-vessel water-level instrumentation were installed, it could help, for years after a meltdown, to characterize fuel reconcentration.

    National and international TMI post-accident assessments, such as NUREG-0933 (Dec. 2011), had formally recognized the “Identification of and Recovery from Conditions Leading to Inadequate Core Cooling” as a high priority. However, similar lessons from the Fukushima meltdowns are buried by the NRC TMI Fukushima Task Force at the bottom of Tier 3 “Enhanced Reactor and Containment Instrumentation.”

    –A. DeVolpi, PhD, retired nuclear-reactor safety specialist

  22. Thats a silly statement Daniel. You could fairly state, no one died from acute radiation poisoning within 20 days at TMI, and have some credibiility , but any time that you release “husky doses” into an environment there are going to be statistical deaths as well as negatively synergistic diseases. It is not JUST cancer that radiation causes. It weakens the whole organism.

  23. Hey Moderator, how many nuclear plants have actually been decomissioned back to “green field” status? Thanks!

  24. Actually, wasn’t Metropolitan Edison Co. the licensed owner operator at the time of the accident, though it was one of a few electric utlities held by General Public Uilities Corporation, a holding company. Ulitmately, TMI 1 and 2 were divested from Met Ed to the ne GPU Nuclear Corporation about 1982, a step in many ways necessary if TMI 1 was to resume operation given the cloud on Metropolitan Edison in light of the accident and other matters involving criminal liability.

  25. And must we remind everyone that no one died from radiation at TMI. Lots of hype. And no one died from radiation at Fukushima. Lots of hype there as well.

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