TMI Update: Jan 14, 2024

Did you catch "The Meltdown: Three Mile Island" on Netflix?
TMI remains a danger and TMIA is working hard to ensure the safety of our communities and the surrounding areas.
Learn more on this site and support our efforts. Join TMIA. To contact the TMIA office, call 717-233-7897.


UCS: “ADVANCE Act” Actually a Retreat on Nuclear Power Safety: Statement by Edwin Lyman, Nuclear Power Safety Director, Union of Concerned Scientists, UCS press release, Jun 17, 2024. 

Statement by Dr. Edwin Lyman, Director of Nuclear Power Safety at the Union of Concerned Scientists (UCS) on the Accelerating Deployment of Versatile, Advanced Nuclear for Clean Energy Act (ADVANCE Act) addition to legislation to reauthorize federal firefighter programs:
“It’s extremely disappointing that, without any meaningful debate, Congress is about to erase 50 years of independent nuclear safety oversight by changing the NRC’s mission to not only protect public health and safety but also to protect the financial health of the industry and its investors. Just as lax regulation by the FAA—an agency already burdened by conflicts of interests—can lead to a catastrophic failure of an aircraft, a compromised NRC could lead to a catastrophic reactor meltdown impacting an entire region for a generation.”
“Make no mistake: This is not about making the reactor licensing process more efficient, but about weakening safety and security oversight across the board, a longstanding industry goal. The change to the NRC’s mission effectively directs the agency to enforce only the bare minimum level of regulation at every facility it oversees across the United States.”
“Passage of this legislation will only increase the danger to people already living downwind of nuclear facilities from a severe accident or terrorist attack, and it will make it even more difficult for communities to prevent risky, experimental reactors from being sited in their midst.”
Nuclear Regulatory Commission - News Release
No: III-24-016 June 14, 2024
Contact: Viktoria Mitlyng, 630-829-9662 Prema Chandrathil, 630-829-9663

NRC Issues Confirmatory Order to Curium US

The Nuclear Regulatory Commission has issued a Confirmatory Order to Curium US documenting an agreed upon set of actions to address 10 apparent violations of NRC requirements that occurred at the Maryland Heights, Missouri, facility.
The company, with North American headquarters in St. Louis, Missouri, is licensed to manufacture and distribute Mo-99/Tc-99m generators, which are used for medical applications such as the diagnosis of heart disease and cancer.
The violations occurred when a technician, as part of cask cleaning and preparation duties, opened a cask containing a contaminated metal component without following the requirement of placing it in the containment chamber that provides radiation shielding. Other workers and parts of the facility were contaminated because the company failed to follow NRC requirements.
There were no exposures exceeding NRC limits for the workers and no exposures to the public.
The company’s officials requested Alternative Dispute Resolution with the NRC. This process uses a neutral mediator to reach agreement about corrective and preventative actions to be taken by the company, which then does not receive a Notice of Violation or a Civil Penalty from the NRC.
The order documents the commitments made by Curium to implement corrective actions, such as revising multiple company procedures and training personnel.
The agency’s January inspection report describes the circumstances of the violations and Curium’s actions following the incident.
Beyond Nuclear Bulletin
June 13, 2024
Nuke leak reaches MS river
The Nuclear Regulatory Commission (NRC) is extending its comment period from June 10, 2024 to June 25, 2024 for the Monticello nuclear power station’s license renewal application for a second 20-year period in Minnesota. Xcel Energy is seeking the approval of a Site-Specific Environmental Impact Statement. Monticello’s current operating license expires September 8, 2030. The nuclear plant will then be 60 years old. This extension seeks to increase its operating license from 60 to 80 years. Monticello’s design is a General Electric Mark I Boiling Water Reactor (BWR), identical to the Japanese reactors that melted down after the March 11, 2011 earthquake and tsunami knocked out all electrical power to keep the reactor cores cool. Email comments to NRC.
Dump appeals to SCOTUS
Interim Storage Partners, LLC, the dump company striving to construct and operate a 40,000 metric ton highly radioactive waste consolidated interim storage facility in Andrews County, Texas, has appealed to the Supreme Court of the United States. In March, by a 9 to 7 vote, the 5th U.S. Circuit Court of Appeals in New Orleans sustained a three-judge panel's earlier ruling which vacated the U.S. Nuclear Regulatory Commission license for ISP's CISF. 
Beyond Nuclear and our environmental coalition partners are reviewing this latest appeal to ascertain our potential role in it, while we also await a ruling by a three-judge panel at the D.C. Circuit, regarding our federal appeals against Holtec's CISF in New Mexico.
Law ends, now what?
The Radiation Exposure Compensation Actthat provided financial compensation for atomic test downwinders in three states and pre-1971 uranium miners, expired on June 10 after attempts to extend as well as expand the bill to include more states and affected communities were killed by the Republican House leadership. Despite passing the Senate with bi-partisan support, House Speaker Mike Johnson refused to offer the expanded version of RECA by the June 7 deadline after pulling an extension-only version of the bill. There is a small chance a separate RECA expansion amendment could be introduced although Republicans are likely to kill it as before. Proponents of RECA expansion described the Republican inaction as an “egregious injustice” and “a travesty”.

The New Nuclear Push, Part 2
Karl Grossman, long-serving host of "Enviro Close-Up" and a founding board of directors member of Beyond Nuclear, has interviewed our radioactive waste specialist for Part 2 of "The New Nuclear Push." Part 1 was published in mid-May. Part 2 focuses on environmental justice impacts related to highly radioactive waste dump fights, including on Western Shoshone land at Yucca Mountain, Nevada, as well as Indigenous and Latinx communities in the Permian Basin of Texas and New Mexico, targeted for consolidated interim storage facilities (see related entry). Part 2 also discusses other pie in the sky schemes, including thorium power, a nuclear weapons proliferation risk, as well as nuclear fusion power, closely related to thermonuclear weapons technology/development facilities.
Beyond Nuclear | 301.270.2209 |
Five Things the “Nuclear Bros” Don’t Want You to Know
About Small Modular Reactors
April 30, 2024    Ed Lyman.  Director, Nuclear Power Safety
Even casual followers of energy and climate issues have probably heard about the alleged wonders of small modular nuclear reactors (SMRs).  This is due in no small part to the “nuclear bros”: an active and seemingly tireless group of nuclear power advocates who dominate social media discussions on energy by promoting SMRs and other “advanced” nuclear technologies as the only real solution for the climate crisis.  But as I showed in my 2013 and 2021 reports, the hype surrounding SMRs is way overblown, and my conclusions remain valid today.
Unfortunately, much of this SMR happy talk is rooted in misinformation, which always brings me back to the same question: If the nuclear bros have such a great SMR story to tell, why do they have to exaggerate so much?
What are SMRs?
SMRs are nuclear reactors that are “small” (defined as 300 megawatts of electrical power or less), can be largely assembled in a centralized facility, and would be installed in a modular fashion at power generation sites.  Some proposed SMRs are so tiny (20 megawatts or less) that they are called “micro” reactors.  SMRs are distinct from today’s conventional nuclear plants, which are typically around 1,000 megawatts and were largely custom-built.  Some SMR designs, such as NuScale, are modified versions of operating water-cooled reactors, while others are radically different designs that use coolants other than water, such as liquid sodium, helium gas, or even molten salts.
To date, however, theoretical interest in SMRs has not translated into many actual reactor orders.  The only SMR currently under construction is in China.  And in the United States, only one company—TerraPower, founded by Microsoft’s Bill Gates—has applied to the Nuclear Regulatory Commission (NRC) for a permit to build a power reactor (but at 345 megawatts, it technically isn’t even an SMR).
The nuclear industry has pinned its hopes on SMRs primarily because some recent large reactor projects, including Vogtle units 3 and 4 in the state of Georgia, have taken far longer to build and cost far more than originally projected.  The failure of these projects to come in on time and under budget undermines arguments that modern nuclear power plants can overcome the problems that have plagued the nuclear industry in the past.
Developers in the industry and the US Department of Energy say that SMRs can be less costly and quicker to build than large reactors and that their modular nature makes it easier to balance power supply and demand.  They also argue that reactors in a variety of sizes would be useful for a range of applications beyond grid-scale electrical power, including providing process heat to industrial plants and power to data centers, cryptocurrency mining operations, petrochemical production, and even electrical vehicle charging stations.
Here are five facts about SMRs that the nuclear industry and the “nuclear bros” who push its message don’t want you, the public, to know.
  1. SMRs are not more economical than large reactors.
In theory, small reactors should have lower capital costs and construction times than large reactors of similar design so that utilities (or other users) can get financing more cheaply and deploy them more flexibly.  But that doesn’t mean small reactors will be more economical than large ones.  In fact, the opposite usually will be true.  What matters more when comparing the economics of different power sources is the cost to produce a kilowatt-hour of electricity, and that depends on the capital cost per kilowatt of generating capacity, as well as the costs of operations, maintenance, fuel, and other factors.
According to the economies of scale principle, smaller reactors will in general produce more expensive electricity than larger ones.  For example, the now-cancelled project by NuScale to build a 460-megawatt, 6-unit SMR in Idaho was estimated to cost over $20,000 per kilowatt, which is greater than the actual cost of the Vogtle large reactor project of over $15,000 per kilowatt.  This cost penalty can be offset only by radical changes in the way reactors are designed, built, and operated.
For example, SMR developers claim they can slash capital cost per kilowatt by achieving efficiency through the mass production of identical units in factories.  However, studies find that such cost reductions typically would not exceed about 30%.  In addition, dozens of units would have to be produced before manufacturers could learn how to make their processes more efficient and achieve those capital cost reductions, meaning that the first reactors of a given design will be unavoidably expensive and will require large government or ratepayer subsidies to get built.  Getting past this obstacle has proven to be one of the main impediments to SMR deployment.
Another way that SMR developers try to reduce capital cost is by reducing or eliminating many of the safety features required for operating reactors that provide multiple layers of protection, such as a robust, reinforced concrete containment structure, motor-driven emergency pumps, and rigorous quality assurance standards for backup safety equipment such as power supplies.  But these changes so far haven’t had much of an impact on the overall cost—just look at NuScale.
In addition to capital cost, operation and maintenance (O&M) costs will also have to be significantly reduced to improve the competitiveness of SMRs.  However, some operating expenses, such as the security needed to protect against terrorist attacks, would not normally be sensitive to reactor size.  The relative contribution of O&M and fuel costs to the price per megawatt-hour varies a lot among designs and project details, but could be 50% or more, depending on factors such as interest rates that influence the total capital cost.
Economies of scale considerations have already led some SMR vendors, such as NuScale and Holtec, to roughly double module sizes from their original designs.  The Oklo, Inc. Aurora microreactor has increased from 1.5 MW to 15 MW and may even go to 50 MW.  And the General Electric-Hitachi BWRX-300 and Westinghouse AP300 are both starting out at the upper limit of what is considered an SMR.
Overall, these changes might be sufficient to make some SMRs cost-competitive with large reactors, but they would still have a long way to go to compete with renewable technologies.  The levelized cost of electricity for the now-cancelled NuScale project was estimated at around $119 per megawatt-hour (without federal subsidies), whereas land-based wind and utility-scale solar now cost below $40/MWh.
Microreactors, however, are likely to remain expensive under any realistic scenario, with projected levelized electricity costs two to three times that of larger SMRs.
2. SMRs are not generally
safer or more secure
than large light-water reactors.
Because of their size, you might think that small nuclear reactors pose lower risks to public health and the environment than large reactors.  After all, the amount of radioactive material in the core and available to be released in an accident is smaller.  And smaller reactors produce heat at lower rates than large reactors, which could make them easier to cool during an accident, perhaps even by passive means—that is, without the need for electrically powered coolant pumps or operator actions.
However, the so-called passive safety features that SMR proponents like to cite may not always work, especially during extreme events such as large earthquakes, major flooding, or wildfires that can degrade the environmental conditions under which they are designed to operate.  And in some cases, passive features can actually make accidents worse: for example, the NRC’s review of the NuScale design revealed that that passive emergency systems could deplete cooling water of boron, which is needed to keep the reactor safely shut down after an accident.
In any event, regulators are loosening safety and security requirements for SMRs in ways which could cancel out any safety benefits from passive features.  For example, the NRC has approved rules and procedures in recent years that provide regulatory pathways for exempting new reactors, including SMRs, from many of the protective measures that it requires for operating plants, such as 


  • a physical containment structure, 
  • an offsite emergency evacuation plan, and 
  • an exclusion zone that separates the plant from densely populated areas.  
  • It is also considering further changes that could allow SMRs to 
  • reduce the numbers of armed security personnel to protect them from terrorist attacks and 
  • reduce the number of highly trained operators to run them. 
Reducing security at SMRs is particularly worrisome, because even the safest reactors could effectively become dangerous radiological weapons if they are sabotaged by skilled attackers.  Even passive safety mechanisms could be deliberately disabled.
Considering the cumulative impact of all these changes, SMRs could be as—or even more— dangerous than large reactors.    For example, if a containment structure at a large reactor reliably prevented 90% of the radioactive material from being released from the core of the reactor during a meltdown, then 
  • a reactor 5 times smaller without such a containment structure could conceivably release more radioactive material into the environment, even though the total amount of material in the core would be smaller.  And if the 
  • SMR were located closer to populated areas with no offsite emergency planning, more people could be exposed to dangerously high levels of radiation.
But even if one could show that the overall safety risk of a small reactor was lower than that of a large reactor, that still wouldn’t automatically imply the overall risk per unit of electricity that it generates is lower, since smaller plants generate less electricity.  
  • If an accident caused a 250-megawatt SMR to release only 25% of the radioactive material that a 1,000-megawatt plant would release, the ratio (of kW/hr) of risk to benefit would be the same.  
And a site with four such reactors could have 
  • four times the annual risk of a single unit, or an 
  • even greater risk if an accident at one reactor were to damage the others, as happened during the 2011 Fukushima Daiichi accident in Japan.
3. SMRs will not reduce 
the problem of what to do
with radioactive waste.
The industry makes highly misleading claims that certain SMRs will reduce the intractable problem of long-lived radioactive waste management by generating less waste, or even by “recycling” their own wastes or those generated by other reactors.
First, it’s necessary to define what “less” waste really means.  In terms of the quantity of highly radioactive isotopes that result when atomic nuclei are fissioned and release energy, small reactors will produce just as much as large reactors per unit of heat generated.  (Non-light-water reactors that more efficiently convert heat to electricity than light-water reactors will produce somewhat smaller quantities of fission products per unit of electricity generated—perhaps 10 to 30%—but this is a relatively small effect in the scheme of things.)  And for reactors with denser fuels, the volume and mass of the spent fuel generated may be smaller, but the concentration of fission products in the spent fuel, and the heat generated by the decay products—factors that really matter to safety—will be proportionately greater.
Therefore, entities that hope to acquire SMRs, like data centers that lack the necessary waste infrastructure, will have to safely manage the storage of significant quantities of spent nuclear fuel on site for the long term, just like any other nuclear power plant does. 
  • Claims by vendors such as Westinghouse that they will take away the reactors after the fuel is no longer usable are simply not credible, as there are no realistic prospects for licensing centralized sites where the used reactors could be taken for the foreseeable future.  
  • Any community with an SMR will have to plan to be a de facto long-term nuclear waste disposal site.
4. SMRs cannot be counted on
to provide reliable and resilient
off-the-grid power
for facilities, such as data centers,
bitcoin mining, hydrogen or
petrochemical production.
Despite the claims of developers, it is very unlikely that any reasonably foreseeable SMR design would be able to safely operate without reliable access to electricity from the grid to power coolant pumps and other vital safety systems.  Just like today’s nuclear plants, SMRs will be vulnerable to extreme weather events or other disasters that could cause a loss of offsite power and force them to shut down.  In such situations a user such as a data center operator would have to provide backup power, likely from diesel generators, for both the data center AND the reactor.  And since there is virtually no experience with operating SMRs worldwide, it is highly doubtful that the novel designs being pitched now would be highly reliable right out of the box and require little monitoring and maintenance.
It very likely will take decades of operating experience for any new reactor design to achieve the level of reliability characteristic of the operating light-water reactor fleet.  Premature deployment based on unrealistic performance expectations could prove extremely costly for any company that wants to experiment with SMRs.
5. SMRs do not use fuel
more efficiently than large reactors.
Some advocates misleadingly claim that SMRs are more efficient than large ones because they use less fuel.  In terms of the amount of heat generated, 
  • the amount of uranium fuel that must undergo nuclear fission is the same whether a reactor is large or small.
And although reactors that use coolants other than water typically operate at higher temperatures, which can increase the efficiency of conversion of heat to electricity, this is not a big enough effect to outweigh other 
  • factors that decrease efficiency of fuel use.
Some SMRs designs require a type of uranium fuel called “high-assay low enriched uranium (HALEU),” which contains higher concentrations of the isotope uranium-235 than conventional light-water reactor fuel.  Although this reduces the total mass of fuel the reactor needs, that doesn’t mean it uses less uranium nor results in less waste from “front-end” mining and milling activities: in fact, the opposite is more likely to be true.
One reason for this is that HALEU production requires a relatively large amount of natural uranium to be fed into the enrichment process that increases the uranium-235 concentration.  For example, the 
  • TerraPower Natrium reactor which would use HALEU enriched to around 19% uranium-235, will require 2.5 to 3 times as much natural uranium to produce a kilowatt-hour of electricity than a light-water reactor.  
  • Smaller reactors, such as the 15-megawatt Oklo Aurora, are even more inefficient.  
Improving the efficiency of these reactors can occur only with significant advances in fuel performance, which could take decades of development to achieve.
Reactors that use uranium inefficiently have disproportionate impacts on the environment from polluting uranium mining and processing activities.  They also are less effective in mitigating carbon emissions, because uranium mining and milling are relatively carbon-intensive activities compared to other parts of the uranium fuel cycle.
SMRs may have a role to play in our energy future, but only if they are sufficiently safe and secure.(1)  For that to happen, it is essential to have a realistic understanding of their costs and risks.  By painting an overly rosy picture of these technologies with often misleading information, the nuclear bros are distracting attention from the need to confront the many challenges that must be resolved to make SMRs a reality—and ultimately doing a disservice to their cause.
About the author
Edwin Lyman is an internationally recognized expert on nuclear proliferation and nuclear terrorism as well as nuclear power safety and security. He is a member of the Institute of Nuclear Materials Management, and has testified numerous times before Congress and the Nuclear Regulatory Commission.

(1) Fission energy is safe if and only if all devices work, everybody does their job, no plant or repository is in any battle — conventional or not, and no quantity of fissionable material is in the hands of the ignorant   No Acts of God permitted.

— Hannes Alfvén
Nuclear Regulatory Commission - News Release
No: 24-045 June 12, 2024
CONTACT: Scott Burnell, 301-415-8200

NRC Seeking Public Comment on Environmental Review of TerraPower Construction Permit Application

The Nuclear Regulatory Commission is seeking public input on the environmental review process for the construction permit application from TerraPower, which seeks permission to build the company’s Natrium nuclear power plant near Kemmerer, Wyoming.
NRC staff members will be in Kemmerer July 16 to describe the environmental review process and gather comments on the issues that should be addressed in the review. Details for the day’s agenda are being finalized and will be available by June 25 on the TerraPower application page and the NRC’s Public Meeting Schedule.
TerraPower, through its subsidiary US SFR Owner, filed the application in March, requesting a permit to build the sodium-cooled, advanced reactor design on a site near an existing coal-fired power plant. The 345-megawatt electric Natrium plant includes an energy storage system to temporarily boost output up to 500 MWe, when needed. If the NRC ultimately issues the permit, TerraPower would need to submit a separate operating license application.
The NRC offers several methods for filing comments on the environmental review before the Aug. 12 deadline, as outlined in a Federal Register notice. Comments can also be submitted via under Docket ID NRC-2024-0078, via email to or via mail to Office of Administration, Mail Stop TWFN-7-A60M, U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001.
A copy of the TerraPower construction permit application, including the environmental report, is available at the Lincoln County Library, 519 Emerald St. in Kemmerer.
Good morning PPL stakeholders,
I am reaching out to notify you that we are planning a Phase IV Residential Electric Vehicle Charging pilot.
PPL anticipates EV adoption to increase significantly over the next several years and we need to understand the potential impact on our systems, as well as potential EE/DSM opportunities. PPL EU’s approved EE&C Plan has funds allocated for pilots, new technology, and experimental equipment; this provides an important opportunity to prepare for Phase V and beyond. The pilot summary can be found below and in the attached presentation:
  • Pilot Design: We plan to incentivize the adoption of connected level 2, ENERGY STAR certified smart chargers, with customer data authorization.
  • Outreach: We will use two primary pathways through dealership partners and direct to customer – downstream rebates and instant discounts on installed chargers.
  • Participation: 1,000 new and existing EV owners
  • Pilot Total Cost: $875K – this includes $300 customer incentive, marketing, platform, and administrative costs.
  • Schedule: This is an 18-month pilot that will last until the conclusion of Phase IV.
There will be benefits for all EDCs including verifying potential future savings in Act 129 for efficient charging equipment. The pilot will also allow us to understand how customers respond to more efficient charging technology, different marketing approaches, and installation options. It will also help us forecast the impact on our system through charging load shapes so we can lay the groundwork for future offerings.
We will provide updates on the pilot during our bi-annual stakeholder meetings. 
Thank you,

Tom McAteer | Manager - Energy Efficiency 
PPL Electric Utilities
827 Hausman Rd.
Allentown, PA 18104
Nuclear Regulatory Commission - News Release
No: III-24-013 June 10, 2024
Contact: Viktoria Mitlyng, 630-829-9662 Prema Chandrathil, 630-829-9663

NRC Proposes $9,000 Civil Penalty to Prein & Newhof

The Nuclear Regulatory Commission has proposed a $9,000 fine to Prein and Newhof for a violation of NRC requirements associated with the control of NRC-regulated material.
The violation involved four examples of failing to appropriately secure portable gauges from unauthorized removal when not under constant surveillance and control. The gauges are used for measuring the moisture content and density of soil and aggregate.
The NRC identified the proposed violations during inspections conducted between April and September 2023. The NRC conducted its inspections at the company’s facilities in Kalamazoo, Cadillac, Muskegon, and Grand Rapids, Michigan, as well as at temporary job sites in Kalamazoo and Muskegon.
During the inspection, another violation was identified. It involved the failure of the company to notify the NRC within 24 hours after a portable gauge was damaged and failed to function as designed. It is of very low risk significance and did not warrant a fine.
Prein & Newhof responded to the violations in writing and documented its corrective actions to prevent recurrence. Details about the company’s responses can be found in the notice of violation.
The company has 30 days to pay the proposed fine or contest it in writing.
Nuclear Regulatory Commission - News Release
No: 24-044 June 4, 2024
CONTACT: Scott Burnell, 301-415-8200
NRC Announces Opportunity to Request a Hearing for the TerraPower Construction Permit Application
The Nuclear Regulatory Commission is announcing an opportunity for the public to request a hearing on a construction permit application from TerraPower seeking permission to build the company’s Natrium nuclear power plant near Kemmerer, Wyoming.
TerraPower, through its subsidiary US SFR Owner, filed the application in March, requesting a permit to build the sodium-cooled, advanced reactor design on a site near an existing coal-fired power plant. The 345-megawatt electric Natrium plant includes an energy storage system to temporarily boost output up to 500 MWe, when needed. If the NRC ultimately issues the permit, TerraPower would need to submit a separate operating license application to obtain permission to run the reactor.
The NRC staff has determined the application contains sufficient information for the agency to formally docket the application and begin its safety and environmental reviews. Docketing the application is not an indication of whether the NRC will issue the construction permit. The notice in today’s Federal Register includes instructions for filing hearing requests. The filing deadline is Aug. 5.
Information about the regulation of new reactors is available on the NRC website. A copy of the TerraPower construction permit application will be available on the NRC website and at the Lincoln County Library – Kemmerer at 519 Emerald St., in Kemmerer.
Subject: Susquehanna Steam Electric Station, Unit 1 - Email of final script to Licensee May 30, 2024 for Verbal Authorization 1RR06, Official Script Susquehanna Steam Electric Station Unit 1 Verbal Authorization 1RR06
ADAMS Accession No.: ML24155A104
Using Web-based ADAMS, select “Advanced Search”
Under “Property,” select “Accession Number”
Under “Value,” enter the Accession Number
Click Search 

FOR IMMEDIATE RELEASE                        30 May 2024

Contact: John LaForge, 715-491-3813, <>; Kelly Lundeen, 715-933-1941,>

U.S. Nuclear Regulatory Commission apologizes for “miscommunication” 
Now says radioactive tritium from Monticello reactor leaked to the Mississippi River

A representative of the U.S. Nuclear Regulatory Commission (NRC) has apologized for public reassurances from its staff that a major leak of radioactive tritium from Xcel Energy’s Monticello nuclear reactor had not reached the Mississippi River, drinking water source for 20 million people including the Minneapolis/St. Paul metro area.

In opening remarks to the NRC-sponsored public hearing at the Monticello Community Center Wednesday, May 15, 2024, NRC Senior Environmental Project Manager Stephen S. Koenick[1], reversed the NRC staff’s often-repeated assurances that leaked tritium from the 53-year-old Monticello reactor had not been detected in the Mississippi River.

Koenick said, “I would like to take a moment to address and clarify some miscommunication regarding the presence of detectable tritium in the Mississippi River. I know we … reported there were no indication[s] of [a] tritium leak [which] made it to the Mississippi. However, … in our Draft Environmental Impact Statement, we … conclude there were some very low concentrations of tritium in the Mississippi River.”[2] Koenick went on to say, “So we apologize for this miscommunication.”

The tritium contamination of the Mississippi is confirmed in Xcel Energy’s May 14, 2024 “Annual Radioactive Effluent Release Report,” submitted to the NRC, which says on page 2, "Tritium was detected in newly developed MW-33A [monitoring well-33A] and MW-37A which resulted in MNGP [Monticello Nuclear Generating Plant] reporting an abnormal discharge to the Mississippi River."[3]

The NRC’s apology regarded several miscommunications made to the press assuring that no detectable tritium had been found by Xcel’s testing of the Mississippi River. On March 18, 2023, NRC spokesperson Victoria Mitlyng told the press that, “There is no pathway for the tritium to get into drinking water.”[4] The NRC’s May 15 public reversal also contradicts Mitlyng’s email message, sent to Nukewatch the evening of the May 15, 2024 public hearing, in which Mitlyng wrote: “As far as the Mississippi River, samples taken from the river so far have not shown increased tritium concentrations.”[5] As recently as May 7, 2024, NRC presenters at an NRC-sponsored public hearing, also held in Monticello’s Community Center, stated on the record that Xcel had found "no detectable levels" of radioactive tritium in the Mississippi River.

Xcel Energy stated in a November 18, 2023 company website posting, “We test the river regularly for tritium and have not found any, indicating that if it is present, it is at such low levels, and is dispersing so quickly, that it cannot be detected by highly sensitive instruments.”[6]

However, the company had previously concluded otherwise. The firm’s July 27, 2023 annual radioactive effluent release report states, “As a result of the continued migration of the Tritium Plume following the abnormal release to the site environs in 2022, MNGP concluded that Tritium had the potential to reach the river. This determination was made after H-3 [tritium] was detected in Monitoring Wells 33A & 37A on July 27, 2023.”[7] Wells 33A and 37A are the two closest to the river. 

Xcel has applied for a second operating license extension which, if granted, would allow the Monticello reactor to run until the age of 80. Public comments on the NRC’s environmental impact statement for the application are being accepted until June 10. To submit comments, see: <> . ###


Notes for verification only

[1]            Stephen S. Koenick, Chief of the Nuclear Regulatory Commission’s Environmental Project Management Branch 1, Division of Rulemaking, Environmental, and Financial Support, Office of                          Nuclear Material Safety and Safeguards. <>

[2]            From transcript of tape recording, Nuclear Regulatory Commission public meeting, Monticello Community Center, Monticello, MN, Wednesday, May 15, 2024.

[3]            Xcel, Monticello Nuclear Generating Plant, Annual Radioactive Effluent Release Report, May 14, 2024, Page 2.

                Monticello Nuclear Generating Plant - 2023 Annual Radioactive Effluent Release Report (

[4]            Associated Press, “Regulators: Nuclear plant leak didn't require public notice”, by Michael Phillis and Amancia Biraben, March 18, 2023,


[5]           Victoria Mitlyng, <Viktoria.Mitlyng@nrc.go>, email to Nukewatch, Wednesday, May 15, 2024

[6]           Xcel website - Monticello Groundwater: Progress on the recovery and treatment of tritium in the groundwater at the Monticello Nuclear Generating Plant, as of Nov. 18, 2023,                               

[7]            “2023 Annual Radioactive Effluent Release Report” for Monticello Nuclear Generating Plant, for the period covering January 1, 2023 through December 31, 2023, p. 9. <>