McMunn v. Babcock & Wilcox Power Generation Group, Inc., 2017 U.S. App. LEXIS 16103 (3d Cir. Aug. 23, 2017):

Plaintiffs assert that they developed cancer¹ after being exposed to excessive radiation emissions from the Nuclear Material and Equipment Company ("NUMEC") facility in Apollo, Pennsylvania (the "Apollo facility"). Plaintiffs do not challenge the District Court's conclusions that their common-law claims against Defendants² were preempted by the Price-Anderson Act and that only their Price-Anderson "public liability" claims are at issue in this appeal. Although the Price-Anderson Act preempted Plaintiffs' common-law negligence claims, Plaintiffs' Price-Anderson public liability claims require Plaintiffs to prove versions of the traditional negligence elements--(1) duty, (2) breach, (3) causation, and (4) damages.

1   For simplicity's sake, we refer to the individuals diagnosed with cancer as "Plaintiffs" even though several of those individuals have died and the executors of those individuals' estates have been substituted as plaintiffs.

2   Defendants are Atlantic Richfield Company and Babcock & Wilcox Power Generation Group, Inc., Babcock & Wilcox Technical Services Group Inc., and B&W Technical Services Inc. Atlantic Richfield Company and Babcock & Wilcox Power Generation Group, Inc., were owners of the NUMEC facility at different points in time. See, e.g., JA1467 (stating that Atlantic Richfield bought the Apollo facility from NUMEC in 1967 and Babcock & Wilcox purchased the facility in 1971).

The District Court held that Defendants were entitled to summary judgment as a matter of law on the Price-Anderson claims because Plaintiffs failed to show that there was a genuine dispute of material fact as to elements of duty, breach, and damages. Plaintiffs appealed. We agree with the District Court: Plaintiffs are missing critical elements, and therefore their claims fail.

Accordingly, we will affirm the judgment of the District Court. [*3]

BACKGROUND

I. THE PARTIES AND EMISSIONS

A. The Parties

Plaintiffs are more than seventy individuals³ in a group of consolidated cases who claim that excessive radiation emitted by Defendants--more specifically, radiation from uranium effluent from the Apollo facility--caused them to develop various cancers.

3   At oral argument, even Plaintiffs' counsel was unable to fix the exact number of plaintiffs. See Oral Arg. Tr. at 4:6-19.

Almost all of the Plaintiffs lived near Apollo, Pennsylvania, for many years, including the 1960s, and almost all of the Plaintiffs were diagnosed with at least one form of cancer between 2007 and 2011.⁴ The similarities among the Plaintiffs end there. By our count, Plaintiffs alleged that they suffered from more than a dozen different types of cancer.⁵ Plaintiffs were of widely varying ages at the times of their diagnoses--with at least one individual under 30 and at least five individuals over 80. See JA3460 (81); JA3478 (82); JA3479 (88); JA3482 (81); JA3485 (29); JA3491 (82). Many of the Plaintiffs had extensive smoking histories, and some had multiple cancer diagnoses over their lifetimes. See, e.g., JA3474 ("smoked about half a pack per day for 40 years"); JA3463 ("diagnosed with breast cancer in 1986 and then again in 2008 at the age of 67").

4   This period of time when most Plaintiffs were diagnosed with cancer may reflect that another group of individuals who developed cancer had previously sued Babcock & Wilcox and Atlantic Richfield Co. Their lawsuit apparently settled before trial. See Docket, Hall v. Babcock & Wilcox, No. 94-951 (W.D. Pa.); see also Hall v. Babcock & Wilcox, No. 94-951, 2007 U.S. Dist. LEXIS 43328, 2007 WL 1740852 (W.D. Pa. June 14, 2007). The diagnosis date range here may also reflect statute of limitations concerns. The statute of limitations is not an issue in this appeal.

5   See, [*4]  e.g., JA3447 ("Non Hodgkin's Lymphoma"); JA3448 ("lung cancer"); JA3449 ("breast cancer"); JA3450 ("esophageal cancer"); JA3451 ("colorectal cancer"); JA3455 ("thyroid cancer"); JA3457 ("kidney cancer"); JA3458 ("endometrial cancer"); JA3459 ("bladder cancer"); JA3465 ("melanoma"); JA3474 ("prostate cancer"); JA3479 ("metastatic ovarian cancer"); JA3485 ("squamous cell tumor of her pelvis").

B. The Facility

The Apollo facility was a "warehouse style building that was not specifically constructed to house the complex manufacturing operation involving radioactive materials." JA1427. As Plaintiffs emphasize, the Apollo facility was adjacent to a steel mill and "in the immediate neighborhood of residential areas." JA1576.

The Apollo facility operated from approximately 1953 to 1983 with uranium fuel manufacture beginning in 1958 and decommissioning beginning in 1978. See JA1467; McMunn v. Babcock & Wilcox Power Generation Grp., 131 F. Supp. 3d 352, 356 (W.D. Pa. 2015).

The Atomic Energy Commission ("AEC") was the federal regulatory body in charge of overseeing the Apollo facility. During the time that the Apollo facility operated, the Nuclear Regulatory Commission ("NRC") became "the statutory successor to the Atomic Energy Commission." In re TMI, 67 F.3d 1103, 1112 (3d Cir. 1995).

The Apollo facility emitted radiation as a necessary byproduct of manufacturing uranium fuel. Plaintiffs argue that that radiation was in excess of regulatory limits. The focus in this dispute is on radiation emitted from the stacks, vents, and fans on the Apollo facility's roof.

C. Evidence of Excessive Emissions

Much of Plaintiffs' evidence of excessive emissions indicates that emissions from the stacks or vents on the roof exceeded [*5]  the maximum permissible concentration ("MPC") for the facility. Plaintiffs do not contest that the relevant maximum permissible concentration is 8.8 disintegrations per minute per cubic meter (dpm/m3). See McMunn, 131 F. Supp. 3d at 373 n.24; Pls.' Br. 10; cf. JA3642.

As discussed below, under the applicable regulations, the maximum permissible concentration is determined at the boundary of the "unrestricted area." Defendants argue that the boundary of the unrestricted area is the boundary of the roof, while Plaintiffs argue that any emissions from any part of the roof--including emission from any stack, vent, or fan--should be less than the maximum permissible concentration.

Plaintiffs point to evidence that they believe supports their position. In a June 5, 1964 letter, the Director of the Division of State and Licensee Relations of the AEC implied that the NUMEC had not shown that the roof was a restricted area: "[T]he roof area of the NUMEC facility is an unrestricted area unless access to this area is controlled from the radiation safety standpoint." JA5314. Consistent with the 1964 letter implying that the entire roof may be unrestricted, Plaintiffs argue that NUMEC and AEC's course of conduct shows that they both thought [*6]  that stack emissions were a regulatory concern because NUMEC and AEC compared stack emissions to the maximum permissible concentration. For instance, in a 1967 report, a NUMEC employee wrote, "[T]he measured stack concentration frequently exceeds permissible levels." JA5201. The AEC similarly expressed concern about releases from stacks, as though the regulations created limitations on the stacks. In a February 5, 1969 letter, the Director of the Division of Compliance of the AEC warned, "Based on your recorded data, the concentrations of radioactive material released from the facility through exhaust stacks to unrestricted areas exceed the limits specified in Appendix B, Table II of 10 CFR 20, contrary to 10 CFR 20.105(a), 'Concentrations in effluents to unrestricted areas.'" JA4700.

In addition to the evidence about emissions from the stacks or vents, Plaintiffs' evidence of excessive emissions fits into one or more of the following three categories: (1) evidence that the monitoring of emissions was not completely comprehensive; (2) data that there was excessive radiation in the area surrounding the facility; and (3) data showing excessive radiation being released but seemingly only for specific, and short, periods [*7]  of time (such as when the facility's incinerator was being used).⁶

6   Our summary of Plaintiffs' evidence mirrors Plaintiffs' own summary presented at the conclusion of oral argument. When asked about "discharges measured at the roof edge," Plaintiffs' counsel (1) asserted that Defendants' "roof edge monitoring . . . is remarkably incomplete"; (2) pointed to an April 20, 1964 letter (discussed below) in which NUMEC admitted that it sometimes exceeded permissible concentrations at the boundary of the roof; (3) highlighted the airborne concentrations of effluent when the plant's incinerator was operating; and (4) noted "environmental monitors in the community." Oral Arg. Tr. at 39:10-40:20.

Plaintiffs marshaled a large number of documents that they alleged created a genuine issue of material fact. The highlights of Plaintiffs' documents are below:

• In an April 20, 1964 letter, NUMEC Manager E.V. Barry wrote to Eber R. Price at the AEC that "average yearly concentrations at our property line" were being exceeded "when the winds are from the south quadrant" or in sections "when the winds are from the east quadrant." JA5163.
• Data for part of the year 1966 shows a high of 41.5 dpm/m3 and an average of 13.0 dpm/m3. See JA5188. But, as Plaintiffs admit, the "high" refers to only one day. See Pls.' Br. 47-48 (referring to "the same day" that the sampler gave its "highest reading"). Additionally, this data comes from a nearby building and not the roof of the Apollo facility. Compare JA5188, with JA5189.
• An August 18, 1967 internal memorandum about the Apollo facility's incinerator states, "Ever since the incinerator has been in operation it has been a consistent source of airborne contamination causing an over exposure [sic] to the operators and air levels above the M.P.C. in and out of the plant." JA4428.
• In [*8]  a February 5, 1969 letter, the Director of the Division of Compliance of the AEC wrote, among other things, "Based on your recorded data, the concentrations of radioactive material released from the facility through exhaust stacks to unrestricted areas exceed the limits specified in Appendix B, Table II of 10 CFR 20, contrary to 10 CFR 20.105(a), 'Concentrations in effluents to unrestricted areas.'" JA4700.
• A November 30, 1972 internal memorandum memorializing a phone call from the AEC states that the AEC commented that "NUMEC has been the worst offender of AEC regulations over the years," that "[t]he AEC is strongly considering imposing civil penalties," and mentions NUMEC was implementing corrective actions in, among other things, its "Liquid Waste Management Program," and "Building Ventilation and Surveillance Program." See JA4439-40.
• In a February 12, 1974 letter, a NUMEC employee criticized the Apollo facility for releasing too much radiation. See JA4422 ("It is . . . apparent from review of the data that said operations at the Apollo Site are not conducted so as to provide a minimal radiological impact on the environment . . . ."). The same letter further states that there was heightened radioactivity in [*9]  the area near the Apollo facility, many times in multiple of the background radiation because of "radiologically contaminated gaseous effluents." Id.
• A July 9, 1974 internal memorandum complains about "stack and liquid discards of SNM [special nuclear material] from the Apollo Plant" and tremendous losses of uranium through "gross irresponsibility." See JA4427.

However, AEC/NRC approved NUMEC's operations at least three times. First, in a report timestamped July 29, 1966, the AEC wrote, "No item of noncompliance with respect to [NUMEC's] concentrations of radioactive effluents released to unrestricted areas was noted as a result of this investigation." JA5051. Second, in 1968, the AEC concluded that NUMEC's roof edge samples were below the maximum permissible concentrations. JA5057 ("As can be seen, these average sample results are below 8.8 [dpm/m3]."). On May 26, 1969, the AEC granted an amendment to NUMEC's license, "authoriz[ing] the discharge of radioactive material from any stack effluent . . . in concentrations up to one-hundred . . . times the applicable limits . . . in accordance with the statements, representations and conditions specified in your application dated March 5, 1969." JA5112. [*10]

Finally, in 1995, the NRC issued a report investigating another NUMEC facility in Parks, Pennsylvania. See 60 Fed. Reg. 35,571, 35,573 (1995). In that report, the NRC stated that, despite the 1969 license amendment setting limits for stack emissions, the regulatory limits were set at the boundary of the roof: "Accordingly, even though NUMEC was authorized to discharge at the stack up to 100 times the value specified in Appendix B, Table II, [under the 1969 license amendment,] NUMEC was still required to meet the limits at the site boundary (see footnote 8)." 60 Fed. Reg. 35,571, 35,573 (1995). Footnote 8, in turn, states, "The values set forth in 10 CFR Part 20, Appendix B, Table II, are the regulatory limits applicable at the site boundary, not at the stack." 60 Fed. Reg. 35,571, 35,573 n.8 (1995).

II. THE SCIENCE OF CANCER

This Court's previous opinion, In re TMI Litigation, 193 F.3d 613 (3d Cir. 1999), set forth the basic scientific principles regarding the relationship between radiation and cancer. See 193 F.3d at 629-55. No party disputes those background principles. Because we rely on these principles here, we consider it helpful to summarize them. Ionizing radiation can damage human cells. Id. at 639-40. "If cellular damage is not repaired, [the damage] may prevent the cell from surviving or reproducing, or it may result in a viable but modified cell." Id. at 640. When an irradiated cell is only [*11]  "modified rather than killed," stochastic (or probabilistic) effects result. Id. at 642.

As the word "probabilistic" indicates, what happens next to the modified cell is uncertain. In some cases, "cancer induction" occurs. Id. As we explained in In re TMI Litigation, any increase in radiation exposure above zero is believed to increase the probability of carcinogenesis⁷:

   The probability that cancer will result from radiation increases proportionally with dose. However, it is currently believed that there is no threshold dose below which the probability of cancer induction is zero. . . . The linear risk model posits that each time energy is deposited in a cell or tissue, there is a probability of the induction of cancer.

Id. at 642-43 (citations omitted).

7   "Carcinogenesis is currently believed to be a multistep process requiring two or more intracellular events to transform a normal cell into a cancer cell." In re TMI Litig., 193 F.3d 613, 643 (3d Cir. 1999).

Even with state-of-the-art data, it is impossible to determine with certainty that radiation is the cause of a given incidence of cancer for three reasons. First, numerous factors other than radiation may cause cancer. That is, "a given percentage of a defined population will contract cancer even absent any exposure to ionizing radiation." Id. at 643-44.⁸ Second, there is no clear difference between cancers caused by radiation or by other factors. No characteristic [*12]  of a given cancer (such as its type or severity) are known to suggest that "manmade" radiation or even any radiation was the cancer's cause. See id. at 643 ("[M]edical evaluation, by itself, can neither prove nor disprove that a specific malignancy was caused by a specific radiation exposure."). Third, because the relevant changes occur on the cellular level, they are not detected or detectable at the time they occur. It can take many years--seemingly a variable number of years--between an exposure to radiation and the "possible detection of a resulting cancer." Id. (defining the "latency period" as "[t]he period between exposure to radiation and possible detection"). Thus, in a case like this one, the factfinder will always have to use ex-post data to ascertain whether any radiation--let alone any particular radioactive exposure--disrupted the cell in the past.

8   "[T]he task of establishing causation is greatly complicated by the reality that a given percentage of a defined population will contract cancer even absent any exposure to ionizing radiation. In industrialized countries where the life expectancy averages about 70 years, about 30% of the population will develop cancer and about 20% of the population will die of cancer." In re TMI Litig., 193 F.3d at 643-44.

III. THE DISTRICT COURT'S RELEVANT RULINGS

We are reviewing the orders granting Defendants' motion for summary judgment. In its summary judgment orders, the District Court adopted the reasoning of the Magistrate Judge to whom all pretrial motions had been referred. See Order, McMunn v. Babcock & Wilcox Power Generation Grp., No. 2:10-cv-00143-DSC-RCM (W.D. Pa. Aug. 24, 2011), ECF No. 79. [*13]

Two earlier rulings set the stage for the summary judgment motion. Those two rulings are (1) a September 12, 2012 order following a "Lone Pine" case management order,⁹ and (2) a February 27, 2014 order adopting in part and rejecting in part the Magistrate Judge's recommendations with regard to excluding the parties' experts under Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 113 S. Ct. 2786, 125 L. Ed. 2d 469 (1993).

9   A Lone Pine order is a pretrial order, based on Lore v. Lone Pine Corp., No. L-33606-85, 1986 N.J. Super. LEXIS 1626, 1986 WL 637507 (N.J. Super. Ct. Law Div. Nov. 18, 1986), that "require[s] plaintiffs to provide facts in support of their claims" including by expert evidence "or risk having their cases dismissed." In re Asbestos Prods. Liab. Litig. (No. VI), 718 F.3d 236, 240 & n.2 (3d Cir. 2013).

A. Lone Pine

On January 25, 2012, the Magistrate Judge issued the Lone Pine order, requiring Plaintiffs to provide prima facie evidence of, among other things, the "name of the specific radionuclide(s) released from Defendants' facilities in excess of the applicable federal permissible limits" and "an identification of each exposure pathway(s) through which each Plaintiff was exposed to each specific radionuclide." Order at 1, McMunn v. Babcock & Wilcox Power Generation Grp., No. 2:10-cv-0143-DSC-RCM (W.D. Pa. Jan. 25, 2012), ECF No. 109.

On September 12, 2012, following the parties' responses to the Lone Pine order, the Magistrate Judge issued an order limiting Plaintiffs' theories of recovery. See McMunn v. Babcock & Wilcox Power Generation Grp., 896 F. Supp. 2d 347 (W.D. Pa. 2012). In that order, the Magistrate Judge held that the Plaintiffs would be allowed only "to pursue, offer [*14]  or rely upon evidence referring or relating to any claim based upon exposure through . . . airborne exposure to uranium . . . from . . . the Apollo facility during its years of operation." Id. at 358-61; see also id. at 364. Plaintiffs do not challenge this Lone Pine order on appeal.

B. Daubert

On July 12, 2013, the Magistrate Judge recommended that the District Court (1) grant some of Defendants' Daubert motions; (2) deny the remainder of Defendants' Daubert motions; and (3) deny all of Plaintiffs' Daubert motions. See McMunn v. Babcock & Wilcox Power Generation Grp., Nos. 10-143 et al., 2013 U.S. Dist. LEXIS 100259, 2013 WL 3487560 (W.D. Pa. July 12, 2013). Specifically, the Magistrate Judge recommended excluding the testimony of Plaintiffs' three general causation experts--Dr. Howard Hu, Dr. Joseph Ring, and Mr. Bernd Franke--and Plaintiffs' specific causation expert, Dr. James Melius. Only the rulings with regard to Melius's testimony bear directly on this appeal.

Melius's expert report used the methodology of differential diagnosis. Melius provided a roughly one-page summary of each Plaintiff's background and alleged exposure and then concluded for each Plaintiff: "[I]t is my professional medical opinion that [Plaintiff's] exposures to uranium and other radioactive materials released [*15]  from the Apollo nuclear facility made a significant contribution to the development of" his or her cancer. E.g., JA3448, 3465, 3490. For most of the Plaintiffs, Melius added language substantially like the following: "This is reinforced by the lack of other risk factors in [her or his] history that would account for the development of this illness." E.g., JA3448.¹⁰

10   For a handful of Plaintiffs--but only some of the Plaintiffs with a history of smoking--Melius identified smoking as the only confounding factor. E.g., JA3451 ("This is reinforced by the lack of other risk factors in his history that would account for the development of this illness other than smoking which also would have made a contribution.").

The Magistrate Judge recommended excluding Melius's testimony because Melius failed to rule out other confounding factors and did not have information about doses of radiation to which each Plaintiff was exposed. With regard to confounding factors, the Magistrate Judge criticized Melius's "differential diagnosis" because Melius "fail[ed] to explain why he did not rule out smoking, obesity, genetic factors, benzene exposure, radon and many other possible and obvious alternative causes in order to conclude in each instance that uranium is the cause of the individual's cancer." McMunn, 2013 U.S. Dist. LEXIS 100259, 2013 WL 3487560, at *28. With regard to dose, the Magistrate Judge criticized Melius for failing to make or use any estimate of any Plaintiff's dose "or the maximum or minimum amount to which the person was exposed." 2013 U.S. Dist. LEXIS 100259, [WL] at *29. Instead, to determine that Plaintiffs' exposures were sufficient [*16]  to serve as a "significant contribution" to their cancers, Melius relied on general testimony about radiation--Dr. Hu's testimony that radiation from uranium could cause cancer--and the assumption that Plaintiffs were exposed to dangerous levels of radiation because "the Plaintiffs lived or worked within 1.5 miles of the Apollo facility." 2013 U.S. Dist. LEXIS 100259, [WL] at *28. The Magistrate Judge's two criticisms dovetailed with a particular flaw in Melius's testimony: Melius "rule[d] out oral contraceptive use if the dose was small and smoking if the person quit 10-15 years ago, thereby taking dose into account." 2013 U.S. Dist. LEXIS 100259, [WL] at *29. The Magistrate Judge concluded that Melius's methodology "has not been generally accepted in the medical and scientific communities" and was "untestable." 2013 U.S. Dist. LEXIS 100259, [WL] at *29.

On February 27, 2014, the District Court rejected the Magistrate Judge's report and recommendation to the extent that the Magistrate Judge recommended granting Defendants' Daubert motions with regard to Melius and Plaintiffs' general causation experts.¹¹ With regard to Melius specifically, the District Court placed great weight on (1) this Court's past discussion of differential diagnosis methodology and (2) the fact that Melius did not have access to perfect information. [*17]  First, the District Court held that Melius "adequately addressed other possible causes of Plaintiffs' cancers, both known and unknown" because Melius reviewed information about the Plaintiffs. McMunn v. Babcock & Wilcox Power Generation Grp., Nos. 2:10cv143 et al., 2014 U.S. Dist. LEXIS 24861, 2014 WL 814878, at *14 (W.D. Pa. Feb. 27, 2014). The District Court also cited and quoted In re Paoli Railroad Yard PCB Litigation, 35 F.3d 717 (3d Cir. 1994), and Heller v. Shaw Industries, Inc., 167 F.3d 146 (3d Cir. 1999), for the propositions that a medical expert performing a differential diagnosis does not need to rule out every alternative factor and that medical experts are permitted to exercise their judgments when conducting a differential diagnosis. See McMunn, 2014 U.S. Dist. LEXIS 24861, 2014 WL 814878, at *15.

11   The District Court adopted the portion of the report and recommendation in which the Magistrate Judge recommended denying the exclusion of Defendants' experts and denying the exclusion of most of Plaintiffs' experts. See McMunn v. Babcock & Wilcox Power Generation Grp., Nos. 2:10cv143 et al., 2014 U.S. Dist. LEXIS 24861, 2014 WL 814878, at *20 (W.D. Pa. Feb. 27, 2014).

Second, with regard to dose, the District Court held that there was "enough support in the record for the contention that the Plaintiffs' exposure levels exceeded the normal background level" for Melius to use a "qualitative analysis" rather than a "quantitative dose analysis." 2014 U.S. Dist. LEXIS 24861, [WL] at *14. In particular, Melius could rely on "NUMEC's failure to monitor emissions." Id. Because Melius's analysis relied on the absence of data, the District Court agreed with Melius that a "quantitative dose calculation . . . may in fact be far more speculative than a qualitative analysis." Id.

The District Court [*18]  further held that a dose analysis was not necessary for Plaintiffs' claims to succeed. The District Court stated that In re TMI Litigation, 193 F.3d 613 (3d Cir. 1999), "did not require a plaintiff prove a quantified dose in order to prove personal injuries caused by the release of radiation." McMunn, 2014 U.S. Dist. LEXIS 24861, 2014 WL 814878, at *13. Then, the District Court cited to other cases that did not require a dose. 2014 U.S. Dist. LEXIS 24861, [WL] at *13-14 (quoting and citing Kannankeril v. Terminix Int'l, 128 F.3d 802, 808-09 (3d Cir. 1997), Bonner v. ISP Techs., Inc., 259 F.3d 924 (8th Cir. 2001), and Westberry v. Gislaved Gummi AB, 178 F.3d 257 (4th Cir. 1999)).

At Defendants' request, the District Court certified the Daubert order for interlocutory appeal. See McMunn v. Babcock & Wilcox Power Generation Grp., Nos. 2:10cv143 et al., 2014 WL 12530940 (W.D. Pa. May 7, 2014). We denied Defendants' petition for interlocutory appeal. See McMunn v. Babcock & Wilcox Power Generation Grp., No. 14-8074 (3d Cir. June 16, 2014).

C. Summary Judgment

On May 7, 2015, the Magistrate Judge filed a very thorough report recommending that the District Court grant Defendants' motion for summary judgment on Plaintiffs' Price-Anderson public liability claims and Defendants' motion for a judgment on the pleadings on all of Plaintiffs' common-law claims. See McMunn v. Babcock & Wilcox Power Generation Grp., 131 F. Supp. 3d 352, 359-404 (W.D. Pa. Sept. 15, 2015) (republishing the report and recommendation).¹²

12   Because Plaintiffs did not appeal the District Court's adoption of the Magistrate Judge's recommendation to dismiss Plaintiffs' common-law claims, we need not discuss the common-law claims.

The Magistrate Judge recommended that the District Court grant summary judgment because Plaintiffs (1) failed "to raise a genuine issue for trial on breach [*19]  of duty" and (2) failed "to proffer evidence of exposure and dose." Id. at 389, 404.¹³ First, with regard to the breach of duty, the Magistrate Judge held that "[t]he regulatory standard applicable to the emission of radionuclides in airborne effluent to off-site areas . . . when the Apollo facility operated . . . was 10 C.F.R. § 20.106"--"not some other regulation, license requirement or other issue." Id. at 368-69, 388; see also In re TMI, 67 F.3d 1103, 1108 n.10 (3d Cir. 1995) (applying "the relevant federal regulations . . . in place at the time" of the radioactive release caused by Three Mile Island accident at issue).

13   The Magistrate Judge did not reach any other issues regarding Plaintiffs' Price-Anderson public liability claims. As the Magistrate Judge noted, Defendants raised other issues in separate summary judgment motions that the District Court denied as moot or denied without prejudice to refile. See McMunn, 131 F. Supp. 3d at 361 & n.3, 404.

Section 20.106 prohibited a licensee from "releas[ing] to an unrestricted area radioactive material in concentrations which exceed the limits specified in Appendix 'B', Table II of this part." 10 C.F.R. § 20.106(a) (1980). The regulation further states that "the concentration limits in Appendix 'B', Table II of this part shall apply at the boundary of the restricted area." 10 C.F.R. § 20.106(d).

The Magistrate Judge rejected Plaintiffs' argument that the Table II maximum permissible concentration applied directly to the uranium effluent released from the stacks on the roof. First, the Magistrate Judge determined that the roof of the Apollo facility was a restricted area. McMunn, 131 F. Supp. 3d at 386-87. Second, the Magistrate Judge held that the measurements [*20]  of uranium effluent to be compared to the maximum permissible concentration should be those taken "at the roof boundary." Id. at 387-88. Because Plaintiffs' only expert testimony about breach applied the concentration limits at the stacks and not at the roof boundaries, the Magistrate Judge held that Plaintiffs failed to proffer expert evidence of a breach that raised a genuine issue of material fact. See id. at 389.

With regard to exposure and dose, the Magistrate Judge held that Plaintiffs' causation case failed because Plaintiffs failed to show that each Plaintiff was exposed to enough radiation to cause his or her cancer. First, the Magistrate Judge granted Defendants' motion to deem certain facts admitted. See id. at 394; Plaintiffs' Local Rule 56.C.1 Response, No. 2:10-cv-001343-DSC-RCM (W.D. Pa. filed Dec. 5, 2014), ECF No. 342. Then, the Magistrate Judge explained that, under In re TMI Litigation, 193 F.3d 613 (3d Cir. 1999), each Plaintiff had to show that he or she was exposed to "inhaled uranium from the Apollo plant in excess of normal background radiation amounts." McMunn, 131 F. Supp. 3d at 396-97, 399. Thus, the Magistrate Judge held that "Plaintiffs must provide . . . an estimate of the dose they received which caused their cancers." Id. at 399. As discussed above, Melius relied on Plaintiffs' other experts [*21]  for exposure, but none of Plaintiffs' other experts calculated exposure or dose for any of the Plaintiffs. See id.

Further, the Magistrate Judge rejected Plaintiffs' argument that Defendants were "estopped from contesting [Plaintiffs'] lack of evidence of exposure and dose" because Defendants failed to keep accurate records. Id. at 402-04. The Magistrate Judge also rejected Plaintiffs' argument that law of the case required the Magistrate Judge to deny summary judgment on causation because the District Court had ruled that Melius's testimony was admissible in its Daubert ruling. See id. at 399-402.

On September 15, 2015, the District Court adopted the Magistrate Judge's report and recommendation over Plaintiffs' objections. See id. at 357. The District Court stated that it "review[ed] . . . the record of these cases, . . . the Magistrate Judge's Report and Recommendation, and the Objections thereto," but offered no further explanation for its decision. Id.

Certain related cases were not consolidated with the main case when the District Court issued its September 15, 2015 Memorandum Order. The District Court ultimately entered orders adopting the reasoning of the September 15, 2015 Memorandum Order in those cases. See JA281-92; SJa3-SJa8. [*22]

Timely notices of appeal followed in each case before us.¹⁴ Additionally, Defendants cross-appealed many--but not all--of the cases before us, requesting that we reverse the District Court's Daubert order.

14   Plaintiffs' Notices of Appeal also objected to orders excluding the expert report of Dr. Steve Wing. See, e.g., Ja1. Because Plaintiffs presented no argument regarding Dr. Wing's report, any issues or objections concerning it have been waived.

JURISDICTION

The District Court had subject-matter jurisdiction over these actions under 42 U.S.C. § 2210(n)(2) because this is a public liability action arising out of a nuclear incident in the Western District of Pennsylvania. This Court has jurisdiction over Plaintiffs' appeals under 28 U.S.C. § 1291.

Plaintiffs argue that we did not have jurisdiction over Defendants' cross-appeal relating to the District Court's denial of their Daubert motion regarding Melius because Defendants are not aggrieved by that denial. As the Supreme Court observed in Deposit Guaranty National Bank v. Roper, "Ordinarily, only a party aggrieved by a judgment or order of a district court may exercise the statutory right to appeal therefrom. A party who receives all that he has sought generally is not aggrieved by the judgment affording the relief and cannot appeal from it." 445 U.S. 326, 333, 100 S. Ct. 1166, 63 L. Ed. 2d 427 (1980); see also Nanavati v. Burdette Tomlin Mem'l Hosp., 857 F.2d 96, 102 (3d Cir. 1988) ("Because they are completely satisfied with the final judgment and object only to interlocutory rulings of the district court, we lack jurisdiction over their [*23]  appeal.").

We need not determine whether we have jurisdiction. We simply follow Third Circuit practice and dismiss Defendants' cross-appeals as "superfluous." Smith v. Johnson & Johnson, 593 F.3d 280, 283 n.2 (3d Cir. 2010) ("Yet a party, without taking a cross-appeal, may urge in support of an order from which an appeal has been taken any matter appearing in the record, at least if the party relied on it in the district court."). As such, we consider the parties' Daubert arguments to concern causation only as an "alternate ground for affirmance." Nanavati, 857 F.2d at 102. Accordingly, we have disregarded Defendants' reply brief in support of their cross-appeal.

STANDARD OF REVIEW

The standard of review on summary judgment is well known: "Because we are reviewing a grant of summary judgment, our standard of review is plenary. Summary judgment is appropriate 'if the movant shows that there is no genuine dispute as to any material fact and the movant is entitled to judgment as a matter of law.'" Constitution Party of Pa. v. Cortes, 824 F.3d 386, 393 (3d Cir. 2016) (citations omitted) (quoting Fed. R. Civ. P. 56(a)).

DISCUSSION

We will affirm the judgment of the District Court because Plaintiffs failed to raise an issue of fact that would allow a reasonable jury to find that Defendants breached their duty and because Melius's conclusory expert report would not allow [*24]  a reasonable jury to find that Defendants' radiation was a substantial factor in causing Plaintiffs' cancers.

I. DUTY

The District Court¹⁵ held that Plaintiff failed to establish a genuine issue of material fact as to whether Defendants breached their duty to Plaintiffs. We agree with the District Court that Defendants' duty was defined by § 20.106.

15   Because the District Court "adopt[ed] the Report and Recommendation as the Opinion of [the District] Court," McMunn v. Babcock & Wilcox Power Generation Grp., 131 F. Supp. 3d 352, 357 (W.D. Pa. 2015), "we will refer to the adopted opinion as that of the district court," USX Corp. v. Liberty Mut. Ins. Co., 444 F.3d 192, 197 n.8 (3d Cir. 2006).

In three different ways, Plaintiffs try to show that Defendants owed a duty other than to prevent the release of uranium effluent that exceeds the maximum permissible concentrations at the boundary of the roof, when the effluent is averaged over a full year. First, Plaintiffs argue that any emission from the roof counts under § 20.106. Second, Plaintiffs argue that more onerous maximum permissible concentrations for roof emissions were created by the 1969 amendment to NUMEC's license. And, third, Plaintiffs argue that they had the option to decline annual averaging, allowing them to find breaches of duty where emissions exceeded the maximum permissible concentration over short periods of time. As discussed below, these attempts to redefine the duty fail because they all conflict with § 20.106 and because we owe Auer deference to the NRC's interpretation of § 20.106.

A. The [*25]  Roof Was a Restricted Area

Under § 20.106(d), the maximum permissible concentrations are assessed "at the boundary of the restricted area." 10 C.F.R. § 20.106(d). A "restricted area" is any area where "access . . . is controlled by the licensee for purposes of protection of individuals from exposure to radiation and radioactive materials." 10 C.F.R. § 20.3(a)(14). Plaintiffs argue that the entire roof was unrestricted¹⁶ such that emissions from anywhere on the roof--including the stacks and fans--should count directly against the limits. Plaintiffs' argument is undermined by a 1995 NRC report that states that the "regulatory limits [are] applicable at the site boundary, not at the stack." 60 Fed. Reg. 35,571, 35,573 n.8 (1995).

16   The definition of "unrestricted area" is merely a mirror of the definition of "restricted area": "'Unrestricted area' means any area access to which is not controlled by the licensee for purposes of protection of individuals from exposure to radiation and radioactive materials, and any area used for residential quarters." 10 C.F.R. § 20.3(a)(17).

Plaintiffs present two arguments as to why the roof is unrestricted: (1) an historical argument based on a series of letters between the AEC and NUMEC and (2) a functional argument that questions whether access to the roof was "controlled by the licensee for purposes of protection of individuals from exposure to radiation and radioactive materials."

With regard to the historical argument, Plaintiffs' strongest support is a June 5, 1964 letter, in which the Director of the Division of State and Licensee Relations of the AEC stated that the roof would be "unrestricted" [*26]  if access were not controlled: "[T]he roof area of the NUMEC facility is an unrestricted area unless access to this area is controlled from the radiation safety standpoint." JA5314.

Plaintiffs also rely on other correspondence in which NUMEC and AEC compared stack emissions to the applicable maximum permissible concentration. For instance, in a 1967 report, a NUMEC employee wrote, "[T]he measured stack concentration frequently exceeds permissible levels." JA5201. The AEC similarly expressed concern about releases from stacks, as though the regulations created limitations on the stacks. In a February 5, 1969 letter, the Director of the Division of Compliance of the AEC warned, "Based on your recorded data, the concentrations of radioactive material released from the facility through exhaust stacks to unrestricted areas exceed the limits specified in Appendix B, Table II of 10 CFR 20, contrary to 10 CFR 20.105(a), 'Concentrations in effluents to unrestricted areas.'" JA4700. Additionally, the fact that NUMEC sought--and the AEC granted in 1969--approval to exceed the maximum permissible concentration by one-hundred times at the stack, see JA5112, suggests that there was a pre-existing regulatory limit at the stack.

Plaintiffs' [*27]  functional argument focuses on the definition of a restricted area in the regulation. The regulation states that a "restricted area" is any area where "access . . . is controlled by the licensee for purposes of protection of individuals from exposure to radiation and radioactive materials." 10 C.F.R. § 20.3(a)(14). It is uncontested that the roof could only be accessed by locked hatches from ladders located inside the building. See JA5035-36 ("There are no outside ladders on NUMEC's property. We have two inside ladders with normally closed and locked hatches at the top."); JA5317 ("The roof hatch is kept locked with keys in the possession of the health and safety technician.").¹⁷

17   Plaintiffs argue that NUMEC conceded that the roof is unrestricted based on the 1966 letter from NUMEC to the AEC that states, "We regard the roof area as an unrestricted area." JA4649. The District Court concluded that "unrestricted" was "a typographical error." McMunn v. Babcock & Wilcox Generation Grp., 131 F. Supp. 3d 352, 378 (W.D. Pa. 2015). At summary judgment, district courts should not determine whether a particular phrasing is a scrivener's error when other possibilities are reasonable. See, e.g., Coffill v. Coffill, 656 F.3d 93, 95-96 (1st Cir. 2011) (holding that it was error to rule that a purported scrivener's error existed "without evidentiary hearing and evidentiary basis"). We agree with the District Court that, in the context of the correspondence in the record and the surrounding sentences, it would be unreasonable or absurd to read that sentence in the 1966 letter as a concession that NUMEC considered the roof "unrestricted." The same paragraph explains the unrestricted areas were at the "roof edge": "[T]he roof edge air samplers are measuring directly the concentration being discharged to unrestricted areas." JA5317.

Plaintiffs argue that these hatches do not show that the roof was "controlled . . . for purposes of protection . . . from exposure to radiation." Relying on a 1965 NUMEC letter, they argue that certain safety measures--e.g., alpha survey instruments--are required to show why the access is controlled. See Pls.' Br. 40-41.

Ultimately, we defer to the expertise of the NRC as to where the restricted area of the Apollo facility ended. In 1995, the NRC issued a report investigating another NUMEC facility in Parks, Pennsylvania. 60 Fed. Reg. 35,571, 35,573 (1995). Even though the report [*28]  was about the Parks facility, the NRC referred to the 1969 letter that allowed NUMEC to exceed regulatory limits at the Apollo facility's stacks. The NRC stated that, despite a 1969 license amendment setting limits for stack emissions, the regulatory limits were set at the boundary of the roof. "Accordingly, even though NUMEC was authorized to discharge at the stack up to 100 times the value specified in Appendix B, Table II, [under a 1969 license amendment,] NUMEC was still required to meet the limits at the site boundary (see footnote 8)." Id. Footnote 8, in turn, stated, "The values set forth in 10 CFR Part 20, Appendix B, Table II, are the regulatory limits applicable at the site boundary, not at the stack." Id. at 35,573 n.8.

Under Auer v. Robbins, 519 U.S. 452, 461-62, 117 S. Ct. 905, 137 L. Ed. 2d 79 (1997), we defer to the NRC's "fair and considered judgment" of its interpretation of its regulation. One could argue that the NRC should receive less deference to the extent that the NRC's 1995 position conflicts with Plaintiffs' historical evidence. In this case, we believe we still owe full deference. The Supreme Court's main concern with an agency switching positions has been with circumstances in which the new position could cause "unfair surprise." Long Island Care at Home, Ltd. v. Coke, 551 U.S. 158, 170-71, 127 S. Ct. 2339, 168 L. Ed. 2d 54 (2007) ("[A]s long as interpretive changes create no unfair [*29]  surprise[,] . . . the change in interpretation alone presents no separate ground for disregarding the Department's present interpretation."). Here, our Auer deference would not harm any reliance interests.

Even if we did not defer to the NRC, Defendants' interpretation of a "restricted area" is more consistent with our precedent than is Plaintiffs' functional argument. In 1995, we held that "[t]he definitions of 'restricted' and 'unrestricted areas' demonstrate that the C.F.R. sections governing persons in 'unrestricted areas' were intended to cover persons outside a nuclear plant's boundaries, i.e., the general public." In re TMI, 67 F.3d at 1114 (footnote omitted). Although denial of access to the "general public" alone does not turn a space into a restricted area, our understanding has been focused more on whether a licensee exercises control rather than on the precise safety measures chosen by the licensee. Other than the isolated statements by NUMEC, Plaintiffs give us no reason to believe that more than locked hatches were needed to control access to the roof for purposes of protecting individuals from radiation.

B. The License Did Not Create a Duty

As noted above, in 1969, the AEC approved NUMEC's request to [*30]  amend its license to allow "the discharge of radioactive material from any stack . . . in concentrations up to one-hundred (100) times the applicable limits specified in Appendix B, Table II," contingent on satisfactory sampling "at the plant roof perimeter" and "in the neighboring unrestricted areas of [the] plant." JA5112. Plaintiffs argue that this 1969 license amendment now creates a tort duty that Defendants violated by discharging more than 100 times the maximum permissible concentration at the stacks.

In a Price-Anderson public liability claim, "federal law preempts state tort law on the standard of care." In re TMI, 67 F.3d at 1107. Our 1995 opinion in In re TMI instructs that the duty that survives preemption must be a regulatory requirement meant to protect people like Plaintiffs. Following In re TMI, we look to the principles of negligence per se (by analogy) and to other courts' interpretation of duty under the Price-Anderson Act. Because this license requirement was only meant to make it easier to assess whether NUMEC violated 10 C.F.R. § 20.106 at the boundary of the restricted area--not to create an independent obligation--we hold this license requirement does not supply a tort duty.

In the 1995 TMI case, plaintiffs [*31]  argued that the "as low as is reasonably achievable" principle ("ALARA") established the tort duty. This Court held instead that 10 C.F.R. §§ 20.105, 106 established the relevant duty. Two of our major considerations were that (1) §§ 20.105 and 20.106 indicated they should apply to effluent emissions to the public, In re TMI, 67 F.3d at 1114, and (2) the ALARA regulation states that it was not "to be construed as radiation protection standards" but was rather meant to be a discretionary tool for regulatory agencies, id. at 1114-15 (internal quotation mark omitted). Thus, we see that our concerns in 1995 reflected (1) whether the regulation was meant to cover the persons allegedly affected and (2) whether the regulation was meant to establish actual standards or operating principles for the agency. These same considerations are not present here. The limitations on the stacks were meant to show levels below which there could not be a violation at the boundary. Thus, they were not directly protective of persons in unrestricted areas and were a discretionary choice by the AEC to make policing NUMEC easier.

The 1995 TMI case also instructs us to consider principles from negligence per se. In that case, we explained that the duty analysis under the Price-Anderson Act [*32]  "is analogous to the practice followed by many jurisdictions with negligence per se cases. In such cases, where defendants violated the relevant statute or regulation, courts have held as a matter of law that plaintiffs have satisfied the first two elements of their cause of action: the duty and breach of duty." In re TMI, 67 F.3d at 1118.

Plaintiffs' objection that we would nullify the license requirements if we refused to use them as the standard of care¹⁸ assumes that every legal requirement must be enforceable by a civil plaintiff. That assumption is contrary to fundamental principles of negligence per se, under which courts must ask "whether the policy behind the legislative enactment will be appropriately served by using it to impose and measure civil damage liability." Frederick L. v. Thomas, 578 F.2d 513, 517 n.8 (3d Cir. 1978).

18   "To hold that NUMEC had no duty to obey the AEC's regulatory caps stated in its license would be tantamount to holding that the AEC had no authority to set those limits." Pls.' Br. 35.

Negligence per se only attaches to a statutory or administrative duty when its direct effect is to prevent the harm at issue to the type of person allegedly injured. See Byrne v. Matczak, 254 F.2d 525, 528 (3d Cir. 1958) ("[T]he general principle is that the violation of a statute will not create a liability unless it is the efficient cause of the injury."); Congini ex rel. Congini v. Portersville Valve Co., 504 Pa. 157, 470 A.2d 515, 518 (Pa. 1983); Restatement (Second) Torts § 286.¹⁹ We have held that "general licensing or permit schemes do not usually establish standards of competence; they do not usually represent [*33]  judgments that a violation of the licensing scheme will generally constitute the breach of a duty to a particular person rather than to the state." Beaver Valley Power Co. v. Nat'l Eng'g & Contracting Co., 883 F.2d 1210, 1221-22 (3d Cir. 1989); see also Talley v. Danek Med., Inc., 179 F.3d 154, 159 (4th Cir. 1999) ("Even if the regulatory scheme as a whole is designed to protect the public or to promote safety, the licensing duty itself is not a standard of care, but an administrative requirement."); Restatement (Second) of Torts § 288 ("The court will not adopt as the standard of conduct . . . the requirements of . . . administrative regulation whose purpose is found to be exclusively . . . to protect the interests of the state or any subdivision of it as such.").²⁰

19   When we adopted 10 C.F.R. §§ 20.105 and 20.106 as the standard of care, we cited Restatement (Second) of Torts for the proposition that a court can adopt regulations as the standard of care. See In re TMI, 67 F.3d at 1113 n.24.

20   Following oral argument, Plaintiffs filed a letter under Rule 28(j) of the Federal Rules of Appellate Procedure with additional cases that showed regulations creating tort duties. None of them is contrary to the reasoning above. Rather, Plaintiffs' 28(j) cases pertain to situations in which statutes explicitly create a duty for license violations, see 33 U.S.C. § 1365(a) ("[A]ny citizen may commence a civil action on his own behalf . . . against any person . . . who is alleged to be in violation of . . . . an effluent standard."); 33 U.S.C. § 1365(f) ("[T]he term 'effluent standard or limitation under this chapter' means . . . a permit or condition thereof . . . ."); N.Y. Veh. & Traffic Law § 509(3) ("Whenever a permit or license is required to operate a motor vehicle, no person shall operate any motor vehicle in violation of any restriction contained on, or applicable to, the permit or license."), or situations where preemption of alternative laws is not as complete as here, see Gomez v. St. Jude Medical Daig Div. Inc., 442 F.3d 919, 928-30 (5th Cir. 2006) (discussing the scope of preemption relating to the Medical Device Amendments).

Finally, as in 1995, we look to other circuits' caselaw as "instructive." In re TMI, 67 F.3d at 1113. Here, we see that no other circuit has adopted Plaintiffs' proposed standard. See Adkins v. Chevron Corp., 960 F. Supp. 2d 761, 766, 772-73 (E.D. Tenn. 2012) (holding that license violations do not create duty in a Price-Anderson public liability action).

The history of the license amendment shows that its purpose was not to create an independent duty to minimize discharge from the stacks. On November 13, 1968, Roger D. Caldwell, NUMEC Manager, Health and Safety, sent a letter to Donald A. Nussbaumer at the AEC. The letter requested a change to NUMEC's license that would "permit[] concentrations up [*34]  to 100 MPC a in any stack's effluent, providing the concentration at the roof edge is permissible." JA5073. Caldwell justified the request by pointing to empirical data relating to diffusion factors at the Apollo facility--that is, by showing that amounts released at the stacks would be much less at the roof edge. See JA5074-76.

On February 5, 1969, Lawrence D. Low, AEC, Director, Division of Compliance wrote to Zalman Shapiro, NUMEC President. Low wrote that "the concentrations of radioactive material released from the facility through exhaust stacks to unrestricted areas exceed the limits . . . contrary to 10 CFR 20.106(a)." JA5079-80. In the same section of the letter, Low acknowledged NUMEC's request that its license "be amended to permit use of a dilution factor for stack effluents." JA6080.

On February 25, 1969, Shapiro responded, explaining that a higher concentration limit could be applied at the stacks to determine whether NUMEC violated its maximum permissible concentration at the roof edge:

   We recognize the necessity for an amendment to our license which would reflect appropriately the means of varifying [sic] the effectiveness of atmospheric dilution in reducing concentration in unrestricted [*35]  areas. In this connection, we submitted on November 13, 1968 a request for an amendment to our license which would place primary reliance on roof perimeter sampling in lieu of stack sampling as a means of measuring releases to unrestricted areas. At a meeting on January 17, 1969 with Licensing and Compliance personnel, it was concluded that the off-site environment sampling program should be included as a part of our license amendment application to provide additional assurance with respect to the effectiveness of atmospheric dilution. Accordingly, we are preparing and will submit by March 7, 1969 a revised application which, if approved, should provide an acceptable means of varifying [sic] compliance with Part 20.

JA5083-84.

On March 10, 1969, Caldwell submitted a "revised application to permit concentration to 100 MPC a in any stack's effluent." JA5087. Again, Caldwell "justified" the proposed limits by pointing to empirical data showing dilution factors at the roof perimeter. Id.

On May 26, 1969, Nussbaumer at the AEC wrote to Caldwell at NUMEC granting the amendment to NUMEC's license "to authorize the discharge of radioactive material from any stack effluent . . . in concentrations [*36]  up to one-hundred . . . times the applicable limits . . . in accordance with the statements, representations and conditions specified in your application dated March 5, 1969." JA5112 (emphasis added). Nussbaumer added, "We consider the environmental sampling program required by Condition 2 above to be a means for providing backup data and evidence that your roof edge sampling results are adequately representative of the concentrations released to the unrestricted areas." JA5112-13 (emphasis added). Thus, even at the time, the AEC, via Nussbaumer, accepted NUMEC's "representations" about the relationship between the stack discharges and the roof edge and that the roof edge monitors would be used to determine the concentrations "released to the unrestricted areas."

In 1995, the NRC agreed that NUMEC's purpose in seeking the amendment assumed that all requirements would be met if the emission at the boundaries were below the maximum permissible concentration: "By application dated November 13, 1968, and supplement dated March 5, 1969, and pursuant to 10 CFR 20.106(b), NUMEC requested that License SNM-145 be amended to permit concentrations up to 100 times the limits specified in Part 20, Appendix B, Table II,  [*37] in any stack effluent, provided that concentrations at the roof edge and in the local environment complied with 10 CFR Part 20 limits." In re Babcock & Wilcox Co., 41 N.R.C. 489, 492-93 (June 26, 1995); see also 10 C.F.R. § 20.106(b). Thus, it is clear that the stack-discharge license restriction was created as a threshold to test for emissions at the boundary of the restricted area.

Because the license requirement was only an administrative safe harbor for NUMEC's compliance with the emissions maximum set at the boundary of the restricted area, it does not create a tort duty here.

C. Plaintiffs Had to Show that Maximum Permissible Concentration was Exceeded on Average Over a Full Year

Section 20.106 states, "For purposes of this section[,] concentrations may be averaged over a period not greater than one year." 10 C.F.R. § 20.106(a) (1980). The District Court's holding that Plaintiffs failed to show a genuine issue of material fact regarding duty was based on Plaintiffs' failure to show a violation of § 20.106 when averaged over the course of a year: "Plaintiffs have pointed to no genuine issues of material fact that the annual average concentration of uranium effluent ever exceeded 1.7 x 10-2 microcuries/milliliter during the period 1957-1960, or that it ever exceeded 4.0 x 10-12 microcuries/milliliter during the period [*38]  1961-1983." McMunn, 131 F. Supp. 3d at 388. On appeal, Plaintiffs continue to argue that they could show a violation based on a discharge that exceeds the maximum permissible concentration over any length of time. Plaintiffs are plainly wrong.

Plaintiffs' argument is based entirely on the word "may" in the phrase "concentrations may be averaged over a period not greater than one year." They argue, "The term may is permissive, not mandatory. There is no requirement to take an average." Pls.' Br. 43 (footnote omitted). We agree with Plaintiffs that "may" is permissive. See, e.g., Simpson v. Kay Jewelers, Div. of Sterling, Inc., 142 F.3d 639, 650-51 (3d Cir. 1998) (comparing "the more flexible and permissive 'may'" to "the mandatory 'must'" (quoting Torre v. Casio, Inc., 42 F.3d 825, 831 n.6 (3d Cir. 1994))).

But Plaintiffs' reliance on a single word in that phrase ignores the fact that it is part of a sentence that speaks in the passive voice. "Phrases constructed in the passive voice use an implied subject or actor who carries out the verb." Sci. Drilling Int'l, Inc. v. Pathfinder Energy Servs., Inc., No. H-06-1634, 2006 U.S. Dist. LEXIS 76821, 2006 WL 2882863, at *3 (S.D. Tex. Oct. 4, 2006). Thus, the question is who has the discretion to decide whether to average annually.

Given the context of the regulation, the obvious answer is that such discretion lies in the AEC because it is the entity charged with determining whether a licensee violates its regulatory duties. Cf. United States v. Brumbaugh, 909 F.2d 289, 291 (7th Cir. 1990) ("The use of the passive voice [*39]  in the statutory language requires us to infer a subject; the most logical inference is that the Attorney General, who has been charged with granting credit under section 3568 for over thirty years, is the intended subject of the sentence."). Plaintiffs' unwritten assumption that the AEC intended for tort plaintiffs or district courts to have discretion to use annual averaging is mistaken. Giving tort plaintiffs the power to determine retroactively the period over which a violation is assessed "would allow [them] to fix the standard case by case and plant by plant. An operator acting in the utmost good faith and diligence could still find itself liable for failing to meet such an elusive and undeterminable standard." In re TMI, 67 F.3d at 1115. Under § 20.106, Plaintiffs were required to show a breach using annual averaging. Their data relating to individual moments in time fails to show a breach.

* * *

Plaintiffs' attempts to expand Defendants' duty must fail. The maximum permissible concentration is assessed at the boundary of the roof, the license requirement does not create a duty, and Plaintiffs must show that the maximal permissible concentration was exceeded when the emissions are averaged annually.

II. BREACH

The District [*40]  Court held that Plaintiffs failed to show there was a dispute of fact as to whether Defendants emitted excessive radiation at the boundary of the roof because Plaintiffs failed to offer appropriate expert testimony.²¹ On appeal, Plaintiffs again rely almost entirely on data from the stacks and roof fans, which, as was established above, are legally irrelevant. See, e.g., Pls.' Reply Br. 15-16 ("NUMEC officials were all too aware of the problem with the roof fans."). Putting aside the stacks and fans data, we agree that Plaintiffs' argument for breach fails for lack of expert evidence in this highly technical area.

21   See McMunn, 131 F. Supp. 3d at 389 ("In addition, to establish a breach of duty, Plaintiffs must offer evidence from a qualified expert that the Apollo facility's emissions exceeded regulatory limits.").

Moreover, Plaintiffs argue that they are "entitled" to "adverse inferences" that allow them to show a breach (and also causation). See Pls.' Br. 22. This, too, fails because Plaintiffs did not show that the District Court abused its discretion in denying the adverse inference.

A. Plaintiffs Needed Experts

Plaintiffs failed to provide an expert who could testify that the data upon which they rely (stacks, vents, and readings from outside the facility) could show a violation of the maximum permissible concentration of uranium effluent at the boundary of the roof when averaged [*41]  annually.

Expert evidence is generally required when an issue is beyond the ken of a lay jury. For instance, in a medical monitoring claim, we explained that the plaintiff had to prove he or she suffered a "significantly increased risk of contracting a serious latent disease" and other factors "by competent expert testimony." Redland Soccer Club, Inc. v. Dep't of Army of U.S., 55 F.3d 827, 845-46, 852 (3d Cir. 1995).²² Similarly, then-Judge Sotomayor wrote for the Second Circuit that expert testimony would be "necessary" where "an injury has multiple potential etiologies." Wills v. Amerada Hess Corp., 379 F.3d 32, 46 (2d Cir. 2004).

22   Cf. also Boring v. Kozakiewicz, 833 F.2d 468, 473 (3d Cir. 1987) ("In some situations in which the seriousness of injury or illness would be apparent to a lay person, expert testimony would not be required, e.g., a gunshot wound. However, those circumstances are not present here." (citation omitted)); Breidor v. Sears, Roebuck & Co., 722 F.2d 1134, 1140-41 (3d Cir. 1983) (stating that expert testimony was necessary to rebut the defendants' contention in a products liability case); Lentino v. Fringe Emp. Plans, Inc., 611 F.2d 474, 480 (3d Cir. 1979) ("Expert testimony is required to establish the relevant standard and whether the defendant complied with that standard, except where the matter under investigation is so simple, and the lack of skill so obvious, as to be within the range of the ordinary experience and comprehension of non-professional persons." (citations omitted) (Pennsylvania medical malpractice case)).

Perhaps recognizing their failure to transmute vent data into roof data, Plaintiffs try to borrow an "average dilution factor of 50" from an isolated 1968 document. See Pls.' Br. 45. But these kinds of calculations are best suited to experts--not lawyers or lay factfinders.

B. The District Court Did Not Abuse Its Discretion in Holding That Plaintiffs Were Not Entitled to an Inference Sufficient to Survive Summary Judgment

Objecting to the report and recommendation, Plaintiffs argued that Defendants' poor recordkeeping allowed them to request an inference under which a jury could assume that Defendants had breached the above-described duty. [See Dist. Ct. ECF No. 376, at 50-53.] By adopting the [*42]  Magistrate Judge's report and recommendation, the District Court rejected this argument. See McMunn, 131 F. Supp. 3d 352.

We review the District Court's denial of the adverse inference for abuse of discretion. See, e.g., In re Hechinger Inv. Co. of Del., Inc., 489 F.3d 568, 574 (3d Cir. 2007) ("We also review the [bankruptcy court's] denial of UFP's motion seeking an evidentiary inference based on spoliation of evidence for abuse of discretion."); Davis v. White, 858 F.3d 1155, 1160 (8th Cir. 2017) ("The district court's refusal to sanction the officers with an adverse inference instruction was not an abuse of discretion.").

Plaintiffs have failed to show that the District Court abused its discretion when determining that an adverse inference was not warranted here.²³ Plaintiffs simply have not developed their argument sufficient to show an abuse of discretion. [See Pls.' Br. 21-22.] In cases where this argument is more developed, an adverse inference may be appropriate. See United States ex rel. Scutellaro v. Capitol Supply, Inc., No. 10-1094 (BAH), 2017 U.S. Dist. LEXIS 59531, 2017 WL 1422364, at *11 (D.D.C. Apr. 19, 2017) (noting several circuits have held that the failure to maintain records allows for an adverse inference). This can be seen by analogy to spoliation cases. In spoliation cases, where there is evidence that one party has destroyed or altered evidence, the opposing party can obtain a "'spoliation inference,' that the destroyed evidence would have been unfavorable [*43]  to the position of the offending party." Schmid v. Milwaukee Elec. Tool Corp., 13 F.3d 76, 78 (3d Cir. 1994). Here, because Plaintiffs failed to show an abuse of discretion, we need not analyze further.

23   Plaintiffs' recordkeeping argument also relates to their failure to provide expert evidence relating to any individual Plaintiff's exposure. See, e.g., Pls.' Reply Br. 18 ("NUMEC's failure to collect data makes calculations impossible--and it should not now benefit from its own malfeasances."). Plaintiffs have also failed to show the District Court abused its discretion when it denied an adverse inference with regard to causation. See McMunn, 131 F. Supp. 3d at 394-96.

***