Introduction
In 2022, Nikki Mazzocchio and Angela Kraus brought suit against Cotter Corporation, alleging that Cotter had improperly disposed of radioactive waste near Coldwater Creek, Missouri, in the years following the Second World War, exposing them to harmful radiation and causing them to eventually develop cancer.
The plaintiffs, two sisters, both spent time in the 1980s and 1990s living and working in Hazelwood, Missouri, a suburb of St. Louis and home to Coldwater Creek.
The Agency for Toxic Substances and Disease Registry (ATSDR) has stated that this area may be linked with certain cancers.
While the ATSDR has not recommended additional general disease screening for individuals who live or have lived in the area, the Public Health Assessment, completed in 2019 at the request of community members, has given plaintiffs some hope that their claims might have merit.
But for Mazzocchio, Kraus, and other plaintiffs looking to prove exposure to this area, their success, at least initially, may turn on preemption, rather than on typical issues of tort liability.
Cotter, following rulings from other circuits, argued for a federal standard of care and that any potential state standard was preempted.
But in October of 2024, the Eighth Circuit ruled that the sisters’ claims, considered “public liability actions” under the Price–Anderson Act (PAA), could proceed using a state standard of care while remaining in a federal forum.
The decision in Mazzocchio created a split with the Third, Sixth, Seventh, Ninth, and Eleventh Circuits, which had all ruled that any state standards of care were preempted in public liability actions.
This Comment explores how the Mazzocchio opinion can change not only the lives of the parties involved in this case but also the balance of federal and state regulatory power. First, Part I offers a brief overview of the field of nuclear safety in general, including the public liability action provided by Congress and the differing forms of implied preemption present. Part II begins by examining how other circuits have treated this issue. It then focuses on the Eighth Circuit’s decision in Mazzocchio, noting its commonsense rationale while acknowledging some possible difficulties. Finally, Part III considers what the Eighth Circuit’s decision could mean for preemption doctrine at large, in particular the development of a new default rule and promotion of new policymaking norms.
I. Preemption in the Field of Nuclear Safety
This Part starts by giving background on the federal scheme for regulating nuclear energy, focusing on the Price–Anderson Act of 1957 and subsequent developments. Then, this Part compares the two types of implied preemption that are present in the field of nuclear safety—field and conflict—and discusses how they create the main question in Mazzocchio.
A. The Field of Nuclear Safety
As the nuclear energy industry emerged in the 1950s, Congress recognized the need for a regulatory scheme to address the potentially massive liabilities associated with nuclear energy development and ensure private investment was not discouraged.
In 1957, that recognition culminated in the passage of the PAA, which governs, among other things, limits on liability for private actors and how plaintiffs may bring claims after nuclear accidents.
And in 1988, as courts were finally working through claims arising out of the Three Mile Island nuclear accident eleven years prior, Congress amended the PAA to create the modern “public liability action.”
An expansive category, public liability actions cover “any suit asserting public liability” following a nuclear incident—anything from direct exposure following a partial reactor meltdown like that which occurred on Three Mile Island
to latent exposure from improper handling and disposal of the kind the plaintiffs alleged in Mazzocchio.
Though courts debated issues of jurisdiction prior to the 1988 amendments,
since then it has been uncontroversial that all public liability actions are heard in the federal district court in the district where the nuclear incident took place.
So while the Mazzocchio plaintiffs originally brought their claims in state court, the claims in this case are public liability actions properly heard in federal court.
Public liability actions “[arise] under section 2210,” of the PAA, and § 2014(ii) goes on to note that “the substantive rules for decision in such action shall be derived from the law of the State in which the nuclear incident involved occurs, unless such law is inconsistent with the provisions of [§ 2210].”
Section 2210, however, does not speak to a standard of care.
On § 2210 alone, any potential jury in the Mazzocchio case would be at a loss in determining whether Cotter is liable for its handling and disposal of radioactive waste. Therein lies the question at the center of this circuit split: Should a state standard of care govern, or would any such standard be preempted by federal law? A federal standard of care could draw from Nuclear Regulatory Commission (NRC) dosage requirements, and both the petitioners and the District Court below have indicated that reliance on such a standard would show that Cotter is not liable.
A state standard of care, however, would allow a jury to consider the evidence in the case and decide whether Cotter met its burden under the common law tort principles of Missouri.
B. Issues of Implied Preemption
All federal preemption doctrine is grounded first in the language of the Constitution’s Supremacy Clause, which states that “[t]his Constitution, and the Laws of the United States which shall be made in Pursuance thereof . . . shall be the supreme Law of the Land.”
But beyond sharing an original source, not all preemption doctrines are created equal. When answering the question posed in Mazzocchio, the Eighth Circuit was dealing with implied preemption.
As opposed to express preemption, in which specific statutory language does much of the interpretive work on its own,
implied preemption often requires courts to sift through statutory language, inquire into congressional intent, and consider how federal and state regulatory schemes will interact in practice.
Additionally, while courts and commentators agree that there are no airtight systems for categorizing implied preemption, two commonly accepted types are field and conflict preemption.
Field preemption exists when the “scheme of federal regulation” is “so pervasive as to make reasonable the inference that Congress left no room for the States to supplement it”—that is, when “the Act of Congress may touch a field in which the federal interest is so dominant that the federal system will be assumed to preclude enforcement of state laws on the same subject.”
This type of implied preemption arises in areas such as aviation and immigration where there is a unique need for uniformity or where national security interests are at play.
On one reading, nuclear safety regulation fits neatly into field preemption. After all, the nuclear energy industry undeniably has roots in national security, and commentators often refer to it as an example of field preemption.
But the Supreme Court has taken a more nuanced approach, refusing to box nuclear safety regulation into any simple preemption category.
Conflict preemption, on the other hand, asks courts to consider whether the state law in question would be an “obstacle to the accomplishment and execution of the full purposes and objectives of Congress”
and “disrupt[] the delicate ‘balance’ Congress sought to achieve.”
The simplest kind of conflict preemption occurs when compliance with federal and state law is actually impossible,
but in reality, conflict preemption often requires a more fine-tuned balancing.
In recent cases, building off the notion that Congress, not the judiciary, is in charge of preemption,
the Court has also indicated a shift away from a freewheeling inquiry and toward a balancing of costs and benefits that draws heavily from the statutory language.
In this case, it is entirely possible that a jury could decide that NRC federal dosage requirements should constitute Missouri’s state standard of care, so the more extreme kind of conflict preemption is less relevant. But whether allowing individual juries to make that decision disrupts the balance Congress has sought to create in nuclear safety regulation is at the heart of Mazzocchio and the other circuit opinions to have considered this question.
II. The Circuit Split
The Eighth Circuit’s decision represents a significant break from other circuit courts, which have largely held that any state standards of care are preempted in a public liability action. Thus, this Part catalogs the other circuits’ decisions and reasonings and then makes an argument for why Mazzocchio, despite its marked departure and some potential problems, is still good law.
A. Other Circuits’ Decisions
The Third, Sixth, Seventh, Ninth, and Eleventh Circuits have all found that state standards of care are preempted by federal law in a public liability action, creating what the Mazzocchio petitioners describe as a five-to-one circuit split.
Following the 1988 amendments creating the modern public liability action, the Third Circuit was the first to consider whether a state or federal standard of care should apply.
After acknowledging the cases called for a case-by-case conflict preemption analysis, the Third Circuit ruled that “any state duty would infringe upon pervasive federal regulation in the field of nuclear safety, and thus would conflict with federal law.”
This approach, while nominally an application of conflict preemption, carries echoes of field preemption,
and it is hard to imagine any state standard of care the Third Circuit would find to not be preempted. Just four years later, that ruling was affirmed in In re TMI, with the panel noting the need for a definitive standard and the dangers it saw in allowing juries to fix standards in each case.
The Third Circuit has signaled some willingness to reconsider this question,
but the TMI cases remain good law, and until the court says otherwise, the Mazzocchio respondents’ arguments to the contrary are speculative.
In 1994, the Seventh Circuit was the first to follow suit, describing adherence to federal regulatory standards as “a necessity.”
That opinion similarly concluded by invoking conflict preemption and the “carefully crafted balance . . . that Congress has achieved.”
But it also invoked the field of nuclear safety multiple times and emphasized that when nuclear safety is at issue, federal safety regulations are the only possible standard of care.
Despite § 2014(ii)’s clear command that state law should supply the substantive rules of decision, in the Seventh Circuit’s view, it was “not appropriate” for anything but a federal regulatory standard to control, and all state standards were preempted.
The Sixth and Ninth Circuits came next, and though their decisions largely agreed with the earlier preemption analyses, they added some important language to the precedent supporting Cotter’s argument in Mazzocchio.
First, the Sixth Circuit noted that public liability actions are “derived from state law . . . to the extent [that] it is not inconsistent with federal law.”
This is a subtle shift away from the exact language of § 2014(ii), but one key to holding that federal law outside of § 2210, primarily federal dosage requirements, can preempt state standards of care. The Ninth Circuit for its part chose to emphasize how “the federal government is in charge of nuclear safety.”
This line of reasoning, while undisputed by any court,
again prioritizes field preemption concepts over the preemption language found in § 2014(ii). Rounding out the circuit split, the Eleventh Circuit first held in 1998 that state standards of care would necessarily be preempted if they were inconsistent with federal radiation exposure regulations.
And while the court more recently held state law to at least supply the relevant statute of limitations, it reiterated that it is “beyond dispute that Congress intended for the federal government, and not the states, to have control over issues of nuclear injury.”
Though the Mazzocchio petitioners did not describe it as part of the circuit split,
the Tenth Circuit has also considered this question on at least two occasions. First, in 2010, the court acknowledged that there was no express preemption of a state standard of care and that defendants would bear the burden of showing that state and federal law conflict.
And while it admitted that sources of federal law outside of § 2210 could preempt state standards of care, it found that the record showed nothing to that effect at the time and directed the district court on remand to allow the defendants to identify other sources of federal law they believed would preempt a state standard of care.
Just five years later, the same parties came before the Tenth Circuit again, and the court had another opportunity to discuss § 2014(ii), even though the defendants had forfeited all preemption arguments other than those about express preemption.
Notwithstanding that procedural defect, the Tenth Circuit still discussed what it described as § 2014(ii)’s “modest form of conflict preemption.”
The court distinguished this from other, clearer cases of field preemption, and it emphasized that state law should apply unless it specifically conflicts with § 2210.
Though this opinion is of lesser precedential value given the court chose not to rule on an issue forfeited by the defendants, the Tenth Circuit’s reasoning laid a framework that the Eighth Circuit built on in Mazzocchio.
B. The Eighth Circuit in Mazzocchio
Despite the fact that the circuit split may not be as severe as petitioners contend, Judge Morris Sheppard Arnold rightly acknowledged in his opinion that a split nonetheless exists.
In just six pages, Mazzocchio focuses on showing that (a) the entire field of nuclear safety is not preempted and (b) state standards of care have an undeniable role to play in public liability actions. The opinion begins by responding to the arguments of other circuits that sound in field preemption, noting that Congress intended to accept the tension that comes with an overlapping system of federal and state law.
The court reasoned that though the Supreme Court in Silkwood v. Kerr-McGee Corp. had only dealt with the issue of punitive damages, it spoke to the larger issue of Congress’s intent in creating a system for regulating nuclear energy that combines state and federal elements.
Other authority from the Supreme Court, it reasoned, also made clear that there are places in the field of nuclear safety where regulatory authority is “expressly ceded to the states,” pointing against field preemption despite the federal government’s overall firm grip on nuclear energy.
Finally, Mazzocchio rightly points out the insufficiency of arguments for field preemption that rely on the inability of states to enact before-the-fact regulations.
Public liability actions, subject to a preemption analysis, draw their rules of decision from state law.
It has been undisputed for nearly one hundred years that “state law” includes not just state statutes or regulations but also state common law, and that remains true here.
After dispensing with arguments that state standards of care are preempted anywhere in the field of nuclear safety, Mazzocchio turns to the specific language of § 2014(ii). Despite the fact that preemption analysis has historically made much of the inquiry into Congress’s intent, with the Supreme Court at times describing congressional purpose as “the ultimate touchstone in every pre-emption case,”
Mazzocchio follows the more recent trend of respecting what Congress did and did not write.
The opinion argues that when § 2014(ii) states that public liability actions draw their substantive rules of decision from state law unless that state law is inconsistent with “such section,” with such section referring only to § 2210, no other federal law can be said to preempt state law.
This approach eschews reading into the intent of either Congress or any given state in favor of adhering to exactly what the statute says. While other circuits, in conducting a balancing test, were wary of other federal regulations,
the Eighth Circuit in Mazzocchio adopted the Supreme Court’s language and referred to those regulations, outside the scope of § 2014(ii)’s text, as merely a “brooding federal interest.”
More than 100 years ago, Justice Oliver Wendell Holmes, Jr., wrote that “[t]he common law is not a brooding omnipresence in the sky, but the articulate voice of some sovereign or quasi sovereign that can be identified.”
Justice Holmes, writing in the era before Erie, was worried about the lack of definite authority behind the general federal common law endorsed by Swift v. Tyson,
but it is not hard to see the similarity between that worry and the “brooding federal interest” language appearing in modern preemption cases. Just as Justice Holmes went on, in another forceful dissent prior to Erie, to write that law does not exist “without some definite authority behind it,”
Justice Neil Gorsuch recently made clear that “[i]nvoking some brooding federal interest or appealing to a judicial policy preference should never be enough to win preemption of a state law.”
Here, such a brooding federal interest still might be compelling if the entire field of nuclear safety were preempted or if Congress had not expressly ceded some authority to states in § 2014(ii), but there is nothing in § 2210, the only section given authority to displace state rules of decision in public liability actions, that speaks to a standard of care.
C. Potential Issues with Mazzocchio
Though the Eighth Circuit’s reasoning in Mazzocchio is sound, the opinion faces several problems when applied to the specific field of nuclear safety. First, nuclear safety implicates serious national security issues.
The United States currently sources around one-fifth of its energy supply from nuclear power,
and politicians from both parties see it as the future of clean energy.
But the high costs of nuclear power and blemishes on its record make the industry very sensitive to changes in regulation,
so a sea change in the way nuclear energy companies are subject to liability may come at too high a price. Second, the staggering damages amounts and spillover effects that can come from a single nuclear incident may make nuclear safety ill-suited to the ad hoc decisionmaking of a jury in any given state.
The facts of the Mazzocchio case center around radioactive waste disposal in the suburbs of St. Louis, and Cotter currently faces at least two other suits from similarly situated plaintiffs.
But nuclear incidents can also have more widespread effects, and it’s not hard to imagine a scenario in which, after this case, a jury in the Eighth Circuit awards a plaintiff a large sum while an identical plaintiff in the neighboring Seventh Circuit would recover nothing. Finally, fears over modern lay jurors’ ability to determine whether private actors have met state standards of care may be well founded. In particular, nuclear energy safety and handling radioactive waste are likely distinguishable from other examples the opinion cites, such as motor vehicle safety and medical devices.
Courts have been willing to allow some breathing room for after-the-fact tort suits in those cases, but many more jurors are likely familiar with motor vehicles or medical devices than with nuclear safety or handling radioactive waste. Federal regulatory standards for nuclear safety are developed by agencies with professional and scientific expertise,
and states, still barred from creating their own before-the-fact regulations for nuclear safety,
might be unable to catch up.
III. Expanding the Eighth Circuit’s Reasoning Beyond the Field of Nuclear Safety
When the Eighth Circuit broke from every other circuit to have considered the question at issue in this case, it was necessarily only ruling on the PAA and the field of nuclear safety. The path charted in Mazzocchio, however, offers a template for how federal and state governments could operate under a new default rule, and this Part argues that it enables more durable and tailored policymaking.
A. A New Default Rule
Preemption is a commonly encountered doctrine, but it is also highly complicated, and even courts sometimes labor to fit cases neatly into the existing preemption taxonomy.
Additionally, for areas like conflict preemption, commentators have advocated a variety of tests, including focusing on either the motives behind or the effects of state laws.
Mazzocchio, however, takes good advantage of a clearly written preemption provision. State law gives the rules of decision in public liability actions unless § 2210 says otherwise.
While Congress may be ill suited to drafting complex preemption provisions,
the case provides a template for when Congress seeks to have overlapping regimes of federal and state law: “In X area, state law applies unless Y says otherwise.” This approach isn’t revolutionary, but it is clear. “Y” might be a specific statutory section, as it is in this case, or it might be a whole statute or a federal agency. For example, Congress could have specified that the NRC and its regulatory requirements would override state law, but it chose not to. Balancing tests might still be necessary if, for example, state law had to be weighed against an entire statute or regulatory scheme, but this approach would avoid scenarios like the one in this case in which courts are split on whether a preemption provision, clear on its face, calls for further inquiry. Congress, not the judiciary, is supposed to control the levers of preemption,
and this default rule would make clear when courts should and should not be stepping in.
B. Durable and Tailored Policymaking
Such a new default rule, beyond being easier to administer, would invite more state action and likely have additional positive effects. Currently, other circuits’ interpretation of preemption provisions similar to § 2014(ii) would always call for a larger inquiry into congressional intent and an involved balancing test.
Especially in areas other than nuclear safety, where states are allowed to enact before-the-fact regulations, the danger that any state law might be preempted likely stunts some state action. But states have a growing role to play as administrative bodies of their own,
and courts should adopt a default rule like the one proposed above that takes advantage of states’ unique position. First, states have an important role in shaping national policy, especially with pendulum swings in policy between presidential administrations.
An increased skepticism of the federal administrative state has accompanied the rise in prominence of the unitary executive theory,
so many major policy initiatives of the last several years have been carried out through informal means or executive orders, only to be overturned at the start of the next administration or shift in power.
California and New York, for example, have already begun responding by filling in policy gaps that appear in areas such as environmental regulation when national policies are hard to rely on.
Second, states can enact policies that are geared toward their own constituencies and likely more responsive to local or regional interests than federal, one-size-fits-all policies. All states lack the resources and reach of the federal government, and within states as well there are serious resource disparities. But state policymaking can happen on a much smaller scale, and public officials can craft policies that represent a larger share of their state’s electorate.
In an era when seismic policy shifts accompany each change in administration and policy is made through less formal and more temporary means, states have an enormous potential to step in and add value in the ways described above. But states could be hesitant to enter the fray if there is uncertainty as to whether regulations they pass could be preempted down the line. Additionally, a default rule like the one proposed gives the federal government a new option when making national policy. With this default rule, the federal government could pass legislation on any subject that leaves enforcement up to individual states, perhaps allowing the federal government to more easily generate consensus in scenarios where states agree something should be done but disagree about what to do.
Adopting a simpler default rule for preemption language can help invite state action and create longer-lasting policies that are tailored to what different regions of the country need.
Conclusion
The victory won by the plaintiffs before the Eighth Circuit in Mazzocchio may end up being short lived. The Supreme Court has called for the Solicitor General to file a brief in the case expressing the views of the United States,
signaling that the Court views this as an important issue and may step in to clarify this unsettled area of the law.
And particularly in the area of nuclear safety, a preference for the federal government in the driver’s seat may eventually win out, especially with states unable to make before-the-fact regulations.
Even so, skepticism of a “brooding federal interest” has been a consistent and growing throughline in recent preemption cases, and the Eighth Circuit’s creation of a circuit split here may be a sign of more preemption problems to come.
Rather than craft increasingly intricate, case-by-case distinctions, courts should follow the approach in Mazzocchio and give Congress a clear default rule to work with when creating regulatory schemes that mix federal and state law. This is especially important given the rise of states as administrative bodies,
and creating a default rule that errs on the side of inviting state action can help to harness states’ policymaking ability. And while disagreements between states may create patchworks of regulation in some areas, this approach will allow policymaking that is more regionally tailored and able to outlast drastic swings in power without completely upending the current system of delegation to the federal administrative state.