Questions for NuScale VOYGR Reactor Certification: When Will It
Be Done? And then, Will It Be Safe?1
By Arjun Makhijani and M. V. Ramana
Final 2023-04-09
Prepared for Environmental Working GroupOf the designs currently planned for deployment, the 77-megawatt NuScale pressurized water
reactor design (named VOYGR) is the farthest along of all small modular reactor (SMR) designs in termsof US Nuclear Regulatory Commission (NRC) certification. But the road forward is unclear; it is likely to
be delayed even more than it already has because of questions about the design’s safety. The saga of
NuScale is one more signal that an SMR boom is going to be a long time coming, if ever.
On November 15, 2022 the NRC staff sent a letter to NuScale regarding its review of“preapplication documents.” i The letter had 99 “significant” observations raising a variety of concerns.
Of these, 11 concerns relating to accidents and reactor transients were completely redacted from thepublic document. In addition, there were six “challenging and/or significant issues” that could affectacceptance of the certification application and/or “be focus areas for…safety review.” Two of the six
involved a critical component for safety and operation – the steam generator. One involved the materialof which reactor vessel and/or containment will be made. Another was about modeling loss-of coolant
accidents, the mechanism that led to Three Mile Island and Fukushima, the most severe light water
reactor accidents thus far.
Despite the serious and numerous deficiencies identified by the NRC in mid-November 2022,
NuScale went ahead with its announced plan to submit a Standard Design Approval (SDA) Application by
the end of 2022 – surely not enough time to fill the essential gaps. And indeed, even as it has begun toreview some materials, the NRC staff has again called out deficiencies in the application materials andcalled on NuScale to provide more information before the application can be formally docketed and thecertification process begun (https://www.nrc.gov/docs/ML2305/ML23058A160.pdf p. 3, italics added):
Please note, however, that the staff’s determination to commence this partial
review of portions of the application does not signify a determination that the NRC staff
will accept the SDA application for docketing and does not preclude the staff fromrequesting further information during its review of the SDA application. In addition, thestaff notes that its commencement of this partial review is undertaken at the applicant’srisk, in that there is no assurance that the SDA application will be accepted for docketing
and review or, if the application is accepted, that it will be approved upon completion of
the staff’s review.

1 This article is about an ongoing process of the review of the NuScale reactor design by the Nuclear Regulatory

Commission and its staff. There have been many twists and turns since the application for a reactor, smaller thanthe one now proposed, was filed in 2016. Those continue; what remains constant are serious safety concerns andcost increases. This article is current as of April 8, 2023 in terms of the review of NRC documents that are publicly
available regarding certification. The NRC comments in 2023, after NuScale filed its Standard Design Approval(SDA) Application at the end of December 2022, do not mention all six “challenging” issues raised in the November
15 pre-application review letter. Presumably they will be reviewed and formally commented on before the SDA
Application is formally docketed.

1Some background and history can clarify the depth and breadth of the NuScale’s problems.
Nuclear plants in the United States have traditionally been licensed using a two-step process. But since
1989, they can also utilize a “combined license that provides a construction permit and an operating
license with conditions for plant operation”.ii Before obtaining a combined license, utilities or nuclear
reactor vendors might also apply for a "design certification (DC) or standard design approval (SDA)” bothof which are generic approvals without reference to a specific site for construction. iii
There are two key differences between a DC and an SDA. The DC requires approval by theCommission whereas the approval only requires the staff to sign off. iv Further, the DC “is considered a
final regulatory decision and is not subject to additional review unless substantial new evidence isdiscovered” whereas an approval is “a quasi-final regulatory decision” with the regulatory staff being“instructed to avoid additional reviews absent new evidence”.v This means that any issues that are
resolved during the design certification rulemaking cannot be brought up later at the combined license
stage.
NuScale started engaging with the NRC in April 2008 when it submitted its first formal preapplication project.vi Until at least 2010, NuScale stated that it expected to submit a design certification
application for a 45 MW-electric reactor design to the NRC in 2012.vii NuScale later revised its design tohave a slightly higher output of 50 MW; it submitted this larger version for certification to the NRC on
December 31, 2016. The NRC granted a standard design approval (SDA) for the 50 MW design in
September 2020.viii
But even before the Commission could evaluate the staff approval, NuScale announced that it
was modifying the design once more to further increase the power output by 20 percent to 60 MW ofelectricity.ix Two years later, NuScale announced another power increase, this time to 77 MW.x
NuScale’s design, evidently, does not seem to be a stable one, constantly increasing its power rating.
NuScale’s website currently (February 2023) does not even mention that the 50 MW design is on offer(https://www.nuscalepower.com/en/products viewed on 2023-02-26); yet the Commission granted thisversion design certification, effective February 2023.xi
In January 2022, NuScale announced that it was “pursuing a new SDA [Standard Design
Approval] for a plant comprised of six integrated pressurized water reactors that can generate 250 MWt(77 MWe) per module.…The SDA application is currently underway and the submittal of the applicationis planned for the fourth calendar year quarter of 2022”.xii In January 2023, NuScale submitted a SDA
application to the NRC for the 77 MW design.xiii The announcement did not mention anything about
pursuing design certification of the 77 MW version. In effect, the over 50 percent increase in power has
restarted the whole standard design approval and certification process.
As part of the renewed process, NuScale gave the NRC staff access to its materials and asked fora “preapplication” review. The staff clarified that the preapplication review was “not part of the NRC’s
official acceptance review process” but was just to understand if there were “any significant issues orinformation gaps between the draft application and the technical content required to be included in the
final application submitted to the NRC”.xiv
The NRC staff was asked to review the documents in NuScale’s own electronic reading room; thematerial was not turned over to the NRC or made public. Keeping the documents in corporate hands
prevents the public from getting them under the Freedom of Information Act. Thus, the public, including
the present authors, cannot review the underlying NuScale materials. Nonetheless, the assessment,
made by the NRC staff in its November 15, 2022 letter and the prior 50 MW documentation together are
revealing; they provide a troubling picture.

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I.

Problems with NuScale’s 50 MW design

The final rule from NRC identified “three issues as not resolved”.xv The NRC stated that it had
insufficient information “regarding (1) the shielding wall design in certain areas of the plant, (2) the
potential for containment leakage from the combustible gas monitoring system, and (3) the ability ofthe steam generator tubes to maintain structural and leakage integrity during density wave oscillationsin the secondary fluid system”. Below, we elaborate on the third issue which we see as especiallyrelevant to the 50 MW design and even more to the 77 MW version.
i.

Steam generators

A major concern that emerged during the 50 MW design certification process was the stabilityof the steam generator;xvi it was identified in a March 2020 letter from the NRC’s Advisory Committee on
Reactor Safeguards (ACRS). xvii The ACRS letter warned that the “design and performance of the steam
generators have not yet been sufficiently validated”. xviii No commercial nuclear power plant uses thesteam generator design proposed by NuScale; the Advisory Committee pointed out that it “introduces
different failure modes”.
The NRC concurred with the ACRS’s findings, reiterating the ACRS’s conclusion that the “design
and performance of the steam generators have not yet been sufficiently validated because of
uncertainties associated with unstable density wave oscillations (DWO) on the steam generator
secondary side”.xix
The integrity of the steam generator is a significant safety concern. In operating pressurizedwater reactors, the primary (reactor) water is pumped through a mass of tubes bent into a U-shape; itnever boils. The secondary water flows vertically past these tubes and boils, with the steam gathering at
the top to be sent to power the turbine-generator set where the electricity is produced. (A simplified
diagram at the NRC website can help visualize this process: https://www.nrc.gov/reading-rm/basicref/students/animated-pwr.html ) The steam generator is outside the reactor vessel but inside thesecondary containment. It is not easy to replace the massive component; but it can be done and has
been done in many pressurized water reactors.
The NuScale design is different. As part of its “passive design”, the primary water circulatesvertically upward from the reactor to the steam generator, which is inside the reactor vessel. The
secondary water circulates in helical tubes, where it boils upon picking up heat as the primary waterflows past the tubes. Two issues, arising from the design, were central to withholding approval of thesteam generator. The first was premature wear of the steam generator tubes. The second, related, issue
concerned vibrations called “density wave oscillations.” Water circulation and vigorous boiling inside
helical tube subjects the tubes to different mechanical forces than current pressurized water reactor
designs.xx These have been extensively studied because “thermally induced oscillations of the flow rateand system pressure are undesirable”; such oscillations “can cause mechanical vibrations, thermal
fatigue, problems of system control, and in extreme circumstances disturb the heat transfer”
characteristics of the system.xxi
As noted, the NRC reiterated concerns expressed by ACRS and was even more specific about the“uncertainties associated with unstable density wave oscillations (DWO) on the steam generator
secondary side”.xxii Yet, the NRC staff stated that further analysis or testing results to “demonstrate thedesign and performance of the steam generators” could be included as part of the application for the
license to construct and operate the reactor,xxiii even though ‘[s]ome uncertainty will remain until a
NuScale Power Module is built and operated”.xxiv

3In punting on the steam generator issue, the NRC also ignored the advice of an ACRS member,
Dr. Vesna Dimitrijevic, who is an expert in probabilistic risk assessment. She also agreed with the ACRS
steam generator analysis but, on that very basis, she dissented from the decision to certify the reactor
before steam-generator-related issues were settled. She wrote that “the steam generator integrity is
too significant of a safety issue to not have received finality in the NuScale design certification” (ouremphasis).xxv
II.

Problems with NuScale’s Preapplication for the 77 MW design

As noted above, in the November 2022 communication, NRC identified 99 “significant”
observations and six “challenging and/or significant issues” that would have to be addressed for thesafety review. We highlight some of them in this brief report.
ii.

Removed information

An overall NRC finding was that NuScale appears to “have removed information needed tosupport a reasonable assurance of public health and safety determination” in its application materials.
The NRC communication did not describe the removed materials in detail; it did imply it might berelated to the large increase in power output by stating that the removal “may” have been related to“the “optimization” effort for the Standard Design Approval (SDA) application….”.xxvi
iii.

Severe accident evaluation

A specific concern identified by the NRC is that the increase in power impacts accident
evaluation: The staff stated that “power uprate to 250 MWth from 160 MWth [i.e., to 77 MW electricfrom 50 MW electric] and other design changes is expected to impact all stages of the Severe Accident
Evaluation, from identified accident sequences, derived source terms, and radiological consequence
analyses”. Yet, the staff noted, it “appears [that] all…‘Severe Accident Progression’, analyses remainunchanged” in NuScale preapplication documents.xxvii This is clearly one of the places where the “newelements” mentioned by NuScale in January 2022 should have been added. Because of the 50 percent
increase in power, accident consequences would be expected to increase. Thus, leaving the accident
analysis “unchanged” seems unjustified. Was NuScale’s intent to check if the NRC staff actually read the
documents? If so, the good news for the public is that the answer appears to be “yes.”iv.

Steam generators

Despite the lapse of over two years since the steam generator concerns were expressed—andthe clear dissent regarding granting certification to the 50 MW reactor design—the NRC has again
identified “Comprehensive Vibration Assessment Plan and Steam Generator Tube Support” and “Density
Wave Oscillation Analysis” as challenges for the 77 MW NuScale design.xxviii In other words, NuScale hasapparently not made much progress in the last two years towards addressing one of the fundamental
safety concerns with its design. Because it is inside the reactor vessel, replacing the NuScale steam
generator, if it fails, will involve cutting open the reactor vessel, with the potential risks of greater
damage to the vessel as well as outer structures. Also complicating the picture is the fact that thereactors would be underwater – locating them in a pool is part of the design.
This is not merely a theoretical concern. The Crystal River Unit 3 nuclear plant had to be shut
down as a result of an attempt to replace the steam generators. This replacement required that a largehole “be made in the containment structure”.xxix After the replacement of the steam generators, thosein charge tried to restore the containment structure, which was observed to have been damaged.
According to the NRC, the “licensee attempted to repair the damage, but later decided to decommission
the reactor”.xxx

4

Steam generator replacements at the units 2 and 3 of the San Onofre Nuclear Generating
Station offer and object lesson closer to the concerns with the NuScale design. Although they had been
replaced at a cost of hundreds of millions of dollars, xxxi the new steam generators experienced leaks andrapid, excessive wear within two years. Eight tubes showed wear of more than 70%, including one
assessed at 100% wear.xxxii Pointing to the need to protect public “health and safety” as well as theenvironment, the NRC put the plant on heightened regulatory review:
to address unexpected degradation of tubes in the newly installed steam generators after
approximately 1.7 and 1 effective full power years of operation, respectively. The purpose ofthis special oversight was to assess the licensee’s evaluation of the cause(s) of unexpected tube
degradation, and verify that the licensee’s corrective actions were appropriate to ensure theintegrity of the steam generator’ and to protect the health and safety of the public and theenvironment.xxxiii
Eventually the utility owners of the plant decided in June 2013 to shut it down permanently
because the various costs associated with the prolonged shutdown, leaks and repairs were deemed too
high to make the plant operational again at full power. xxxiv
The challenge in the case of NuScale is much greater. Steam generators are both essential tooperating the plant—a steam turbine is necessary to drive the electric generator—and to safety, since it
keeps the radioactive water in the primary reactor loop separate from the rest of the plant and theenvironment. Therefore, in addition to safety concerns, the financial implications of such a major repair
might well be fatal to the economics of a NuScale plant. It is entirely possible that, if the steam
generator fails, the reactor might have to be shut down permanently, the equivalent of having to junk a
car because it is too costly and difficult to replace a failed transmission.
Compared to 2020, there is even more reason to be concerned now; the challenges with thesteam generator have likely increased with the large increase in power output.
NuScale also proposes a higher burnup of the nuclear fuel to an average 45 gigawatt-days
thermal per metric ton of uranium (GWdth/tU), up from around 35 GWdth/tU for the earlier design.xxxv
The burnup represents the amount of thermal energy that the reactor produces on average per unit ofuranium fuel; the greater the burnup, the higher the concentration of radioactivity in the core. The
higher radionuclide inventory in the reactor and in the spent fuel pool is a central reason for carrying out
a new accident analysis. If there is a loss-of-coolant accident the residual heat in the reactor core will behigher, enabling faster deterioration of conditions. This is likely an additional reason for the NRC staff toraise the loss-of-coolant accident analysis as a “significant issue” that may affect the acceptance of thedesign approval application and/or be a focus of a safety review. A loss-of-coolant accident is arguably
the most important safety concern for light water reactors and thus a major focus of regulatory review
in any case. NuScale staff are surely aware that the increase in burnup and steam throughput require a
new analysis of loss-of-coolant accidents (among other things).
The concerns about steam generator-related safety issues have not abated after NuScale
submitted its application for Standard Design Approval at the end of 2022. The NRC staff then carriedout a first stage review to check whether the information provided was sufficient to formally docket theapplication and begin the formal SDA review process. In March 2023, the NRC staff informed NuScale(ref: https://www.nrc.gov/docs/ML2305/ML23058A160.pdf ) that the documentation it had provided
was “missing sufficient information in the following areas”:•“Scope of the methodology for calculating DWO [Density Wave Oscillations] andthe full applicability range, conditions, and figures of merit;5•“Testing that was performed including test results and test data;•“Comparisons of test data to the analysis models and justification for theapplicability of the models for evaluation of the SDAA design; and•“Evaluations of the effect of DWO on safety system performance during all
operating conditions including normal operation, LOCAs, [Loss of Coolant
Accidents], Non-LOCAs, and extended passive cooling.”

This is an impressive list; the issue of density wave oscillations and the safety of the helical steam
generators continue to fester. If anything, the NRC staff’s rationale for the additional information
reinforces prior concerns (ibid., pdf p, 5):
DWOs or other instability phenomena can lead to a disruption in the flow of coolant
through the steam generators and may challenge steam generator tube integrity. Thesemay have adverse impacts on fission product barriers which could result in a release ofradioactive material and potential offsite doses.
The NRC has given NuScale until September 2023 to submit the information it has requested from
NuScale (ibid. p. 2) The evaluation of its completeness and suitability of the entire application to beformally docketed will follow submittal of the documents.
Why did NuScale not provide the requisite new elements to the NRC in its preapplication review
or even in its formal submittal of the SDA? Was there a hope that somehow the NRC would accept
incomplete documentation on critical issues and docket the application, so the company could present
the public with evidence of progress on certification? Are the increasing financial pressures on NuScalecreating a rush to file an application to raise more funds from the public and convince prospective
customers to stick with its design?
III.

Challenges with the NuScale project in Idaho

The first NuScale project is proposed to be constructed in Idaho with electricity to be purchased
by Utah Associated Municipal Power Systems (UAMPS). In a nod to the inability to find enough takers forthe power, UAMPS has officially reduced the plant size “from 12 NuScale Power Modules to 6
modules”,xxxvi which together will produce 462 MW (gross) of electricity. Each of the six modules is togenerate 77 MW, instead of the prior 50 MW, presumably to take advantage of economies of scale. Inpart because eight municipalities withdrew from the project in October 2020, ahead of one of thescheduled “off-ramps”,xxxvii the total subscription for the UAMPS project, measured in terms of signed
power sales contracts, amounted to just 101 MW as of October 2021.xxxviii
The withdrawals from the project were partly a result of successive cost escalations, which by2020 had resulted in a project cost estimate of $6.1 billion for a 720 MW, twelve module design.xxxix
Following the withdrawals, UAMPS modified its plan to only include six modules, each of 77 MW. But
when evaluated in terms of cost per unit of generation capacity, that did not fix the cost problem:
according to a November 2021 article by the CEO of UAMPS, the “actual all-in estimated cost of the six
module/462 MWe project, including financing, inflationary costs, etc., is $5.32 billion”. xl Since then, thecosts of the UAMPS project have gone up substantially.xli
On January 2, 2023, UAMPS released a set of “talking points” that provided a new cost estimate:from the $5.32 billion, the project is now estimated to cost an eye-popping $9.3 billion for just 462 MWof power capacity.xlii In per kilowatt terms, that estimate for the UAMPS project is around 250% morethan the initial per kilowatt cost for the Vogtle project in Georgia, which consists of two AP1000 reactors

6capable of generating 1250 MW each (gross capacity), at a comparable stage – that is, when it was stillon paper. The Vogtle cost has since exploded from $14 billion to over $30 billion as the reactors nearcompletion.xliii A similar fate may await the UAMPS project if and when construction starts. After all,nuclear reactors have routinely exceeded initial cost estimates. One historical survey found that 175 out
of 180 nuclear construction projects had experienced cost increases and delays. Cost escalations
averaged 117 percent; and construction took 64 percent longer on average than projected.xliv And thecost of the UAMPS project will likely further increase prior to start of construction, especially if NuScale
has to modify its design to address the safety issues identified by ACRS and NRC.
Even before the recent escalation in costs, NuScale has been struggling to raise investment
capital. Its key investor, Fluor, has been systematically trying to reduce its equity stake in NuScale andhas ceased to invest in it; as a result, NuScale is looking for other investors. xlv As early as 2019, a seniorCredit Suisse analyst wrote to investors recommending that Fluor could reduce “underperforming
investments,” including its NuScale small modular nuclear reactor startup “which is long overdue, in our
opinion”.xlvi The NuScale holding is a very small part of Fluor, which is a large, multi-billion dollar
multinational construction and engineering firm.
As of 2021, the total investment in NuScale has been over $1.1. billion, including around $400
million from the Department of Energy (DOE). xlvii The DOE has supported NuScale through competitive
and non-competitive awards, most prominently a $226 million award from 2014-18 and an ongoing$263 million award for 2020-24. In 2020, DOE also awarded $1.355 billion for the UAMPS NuScaleproject to be used by 2030.xlviii The Government Accountability Office (GAO) has criticized the lack ofoversight of these awards; as of September 2022, when the GAO published its report, DOE’s Office of
Nuclear Energy were still “developing their oversight plans”. xlix
Despite this handsome support from the DOE, NuScale is clearly in need of much more funding.
Specifically, NuScale has created a special purpose acquisition company (SPAC) as a way to obtain publicmoney.l In April 2022, two Japanese companies, Japan NuScale Innovation and Japan Bank forInternational Corp., purchased a part of Fluor’s equity in NuScale for $110 million. li Fluor, however,“remains the majority owner in NuScale”.lii NuScale’s stock price (Symbol: SMR) has been stagnant
around $10 per share. Capital woes may well be part of NuScale’s rush to get in a certification
application.
Prior cost increases were likely a factor in NuScale’s decision to increase the size of the reactor
from 50 MW to 77 MW, with the attendant certification headaches and delays, and in the decision toincrease the targeted burnup of the fuel: higher burnup reduces the average refueling outage time. But
those efforts at economy have had a cost: reanalysis of the outstanding operational safety issues as wellas the consequences of accidents – both of which are made more complex by the increased power.
IV.

Conclusion

Anyone looking at NuScale’s website, might well think that the 77 MW VOGR is ready to go:
VOYGR™ SMR plants are powered by our innovative NuScale Power Module™, thefirst and only small modular reactor (SMR) to receive design approval from the U.S.
Nuclear Regulatory Commission (NRC).
(https://www.nuscalepower.com/en/products/voygr-smr-plants _In fact, the 77-MW VOYGR has not received standard design approval, much less full Commission
certification. On the contrary, it has received a letter from the NRC staff with 99 “significant”
observations and six major challenges. These problems need real-world analysis, design, and mostimportant, real-world testing to be resolved. Premature wear of the steam generators and their7

potential failure were not analyzed properly and insufficiently tested even for the 50 MW design. The
hurdles are even higher with the 77-MW version.
Specifically, the testing of the steam generators was under conditions that did not adequately
represent reactor operation. The ACRS noted that the onsite instabilities were studied by “reducing
the flow in small steps until unstable oscillations developed….” It noted the difference with real
operational conditions as follows:
Actual oscillations may be larger than those observed in these tests. Differences
between these scaled experiments and the actual design of the steam generator
introduce uncertainty about the applicability of the data. Historically in two-phase flow
experiments, small configuration differences have resulted in behavior observed inexperiments that were not observed in the actual reactor. Thus, some uncertainty willremain until a NuScale Power Module is built and operated.liii
The ACRS also noted the related analytical weaknesses in regard to NuScale’s analysis of accidents. It
stated that the modeled accident, which postulated the rupture of a single tube, “may not be thelimiting event. This also suggests that the estimate of containment bypass under such conditions may beunderestimated in the probabilistic risk assessment”.liv
One would hope that this time around, the NRC staff will insist that the issues related to wear of
the tubes, steam generator instability, and limiting accident be thoroughly addressed before standard
design approval. This is more important now, since the potential consequences have intensified with theincrease in power from 50 MW to 77 MW. Will the NRC staff take the dissent of its own probabilistic risk
assessment expert on the ACRS to heart this time before giving standard design approval? And if it does
not, will the Commission do so?
Both the NRC staff and the Commission postponed essential safety concerns, including thosewith the steam generator in giving the green light to the 50 MW design. But simplification ofcertification should not compromise safety. Will the NRC do a careful and thorough job this time before
granting certification to the 77 MW version? How long will approval take if it does so? Our best answer
is that it will not be anytime soon.
The pressures to unveil the age of SMRs are great. Will the NRC bend to them? Or will it stepback from its posture in the 50-MW NuScale certification process of treating those who invest in the first
NuScale plant, who commit to purchasing its power, who work in it, and who live near it as neighbors as
unwitting test subjects in the cause of promoting SMRs?
i NRC, “Preapplication Readiness Assessment Report” (Washington, D. C.: Nuclear Regulatory Commission,

November 15, 2022), https://s3.documentcloud.org/documents/23321003/nuscale-sdaa-preapplicationreadiness-assessment-summary-observation-report-final-4.pdf.
ii NRC, “Backgrounder on Nuclear Power Plant Licensing Process,” United States Nuclear Regulatory
Commission, June 7, 2022, https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/licensing-process-fs.html.
iii Jacopo Buongiorno et al., “The Future of Nuclear Power in a Carbon-Constrained World” (Massachusetts
Institute of Technology, 2018), 127–28, https://energy.mit.edu/wp-content/uploads/2018/09/The-Future-ofNuclear-Energy-in-a-Carbon-Constrained-World.pdf.
iv NRC, “Part 52 - Licenses, Certifications, and Approvals for Nuclear Power Plants,” Nuclear Regulatory
Commission, February 21, 2023, https://www.nrc.gov/reading-rm/doc-collections/cfr/part052/full-text.html.
v Buongiorno et al., “The Future of Nuclear Power in a Carbon-Constrained World,” 128.

8

vi Bruce Landrey, “NuScale Power – Safe, Economic, Scalable, Proven Nuclear Technology” (Idaho Falls,

Idaho, USA, August 10, 2012), https://line.idaho.gov/wp-content/uploads/sites/12/2016/07/NuScalePresentation.pdf.
vii “Are Smaller Reactors Better?,” Power Magazine, November 1, 2010, https://www.powermag.com/aresmaller-reactors-better/; Wayne Barbe, “NuScale Sees Large Upside in Small Nuclear Units,” SNL Energy Power
Daily, June 30, 2010.
viii NuScale, “U.S. Nuclear Regulatory Commission Issues Standard Design Approval for NuScale’s SMR
Design,” News Releases (blog), September 14, 2020, https://nuscale-prod-o3ff7klg8-nuscalepower.vercel.app/news/press-releases/2020/us-nrc-issues-standard-design-approval-for-nuscales-smr-design.
ix NuScale, “Breakthrough for NuScale Power; Increase in Its SMR Output Delivers Customers 20 Percent
More Power,” News Releases (blog), June 6, 2018, https://newsroom.nuscalepower.com/press-releases/newsdetails/2018/Breakthrough-for-NuScale-Power-Increase-in-Its-SMR-Output-Delivers-Customers-20-Percent-MorePower/default.aspx.
x NuScale, “NuScale Power Announces an Additional 25 Percent Increase in NuScale Power Module TM
Output; Additional Power Plant Solutions,” News Releases (blog), November 10, 2020,
https://www.nuscalepower.com/en/news/press-releases/2020/nuscale-power-announces-an-additional-25percent-increase-in-nuscale-power-module-output.
xi NRC, “NuScale Small Modular Reactor Design Certification,” Federal Register, January 19, 2023,
https://www.federalregister.gov/documents/2023/01/19/2023-00729/nuscale-small-modular-reactor-designcertification.
xii NuScale, “NuScale Power, LLC Letter of Intent Providing the Carbon Free Power Project (CFPP)
Combined License Application (COLA) Response to NRC Regulatory Issue Summary 2020-02 and Regulatory
Engagement Plan—Carbon Free Power Project (CFPP) Regulatory Engagement Plan” (Corvallis, USA: NuScale Power
Inc., January 28, 2022), https://www.nrc.gov/docs/ML2202/ML22028A277.pdf.
xiii “NuScale Builds Upon Unparalleled Licensing Progress With Second Standard Design Approval
Application Submittal,” News Releases (blog), January 2023, https://nuscale-prod-fragindto-nuscalepower.vercel.app/news/press-releases/2023/nuscale-builds-upon-unparalleled-licensing-progress-with-secondstandard-design-approval.
xiv NRC, “Preapplication Readiness Assessment Report.”
xv NRC, “NuScale Small Modular Reactor Design Certification.”
xvi Supplementary Information, NRC, “RIN 3150-AJ98: NuScale Small Modular Reactor Design Certification”(Rockville, MD: U.S. Nuclear Regulatory Commission, 2022),
https://www.nrc.gov/docs/ML2200/ML22004A005.pdf.
xvii Jessica Sondgeroth, “A Pox on NuScale’s SMR Design Certification,” Nuclear Intelligence Weekly, May
15, 2020.
xviii Advisory Committee on Reactor Safeguards, “NuScale Area of Focus - Helical Tube Steam Generator
Design,” Nuclear Regulatory Commission, March 24, 2020, https://www.nrc.gov/docs/ML2009/ML20091G387.pdf.
xix NRC, “Subject: NuScale Area of Focus - Helical Tube Steam Generator Design,” Nuclear Regulatory
Commission, May 1, 2020, https://www.nrc.gov/docs/ML2010/ML20107F849.pdf.
xx Junwei Hao et al., “Analysis of Density Wave Oscillations in Helically Coiled Tube Once-Through SteamGenerator,” Science and Technology of Nuclear Installations 2016 (December 15, 2016): e3071686,
https://doi.org/10.1155/2016/3071686.
xxi M. Colombo et al., “Experimental Investigation of Thermal Hydraulic Instabilities in Steam Generator
Helical Coil Tubes” (Milano, Italy: Accordo di Programma Ministero dello Sviluppo Economico – ENEA, 2011), 7,
https://www.enea.it/it/Ricerca_sviluppo/documenti/ricerca-di-sistema-elettrico/nuovo-nucleare-fissione/lp2/rds105-lp2.pdf.
xxii NRC, “Subject: NuScale Area of Focus - Helical Tube Steam Generator Design,” May 1, 2020.
xxiii Michael McAuliffe, “NRC Raises Questions about NuScale Design, Delays Interim Review Milestone,”
Nucleonics Week, May 7, 2020.
xxiv NRC, “Subject: NuScale Area of Focus - Helical Tube Steam Generator Design,” May 1, 2020.
xxv Advisory Committee on Reactor Safeguards, “NuScale Area of Focus - Helical Tube Steam Generator
Design,” Nuclear Regulatory Commission, March 24, 2020, 4,
https://www.nrc.gov/docs/ML2009/ML20091G387.pdf.

9xxvi NRC, “Preapplication Readiness Assessment Report.”
xxvii NRC.
xxviii NRC.
xxix NRC, “Crystal River Unit 3 Nuclear Generating Plant,” United States Nuclear Regulatory Commission,

April 13, 2022, https://www.nrc.gov/info-finder/decommissioning/power-reactor/cr3.html.
xxx NRC.
xxxi “SONGS Replacement Steam Generators Project,” Power Technology, April 19, 2011,https://www.power-technology.com/projects/songs-steam/.
xxxii NRC, “SONGS Unit 3 Failed In-Situ Pressure Tests,” Nuclear Regulatory Commission, March 11, 2020,
https://www.nrc.gov/reactors/operating/ops-experience/tube-degrade/failed-pressure-tests.html.
xxxiii NRC, “SONGS Steam Generator Tube Degradation,” Nuclear Regulatory Commission, March 11, 2020,
https://www.nrc.gov/reactors/operating/ops-experience/tube-degradation.html.
xxxiv “Southern California Edison Announces Plans to Retire San Onofre Nuclear Generating Station,” Edison
International Newsroom, June 7, 2013, https://newsroom.edison.com/releases/southern-california-edisonannounces-plans-to-retire-san-onofre-nuclear-generating-station.
xxxv Jose N. Reyes, “NuScale Responds to SMR Critique,” Letter to PNAS editor-in-chief May R. Berenbaum,
June 2, 2022, https://www.ans.org/news/article-4013/nuscale-responds-to-smr-critique/; Lindsay M. Krall, Allison
M. Macfarlane, and Rodney C. Ewing, “Nuclear Waste from Small Modular Reactors,” Proceedings of the National
Academy of Sciences 119, no. 23 (May 31, 2022): e2111833119, https://doi.org/10.1073/pnas.2111833119.
xxxvi UAMPS, “December Carbon Free Power Project Update,” Clean Energy News, December 28, 2021,
https://www.uamps.com/File/9ebaf0bf-4d0a-4073-9ba4-c6e63cdc44c4.
xxxvii Sonal Patel, “Shakeup for 720-Mw Nuclear SMR Project as More Cities Withdraw Participation,”
Power Magazine, October 29, 2020, https://www.powermag.com/shakeup-for-720-mw-nuclear-smr-project-asmore-cities-withdraw-participation/.
xxxviii UAMPS and Utah Associated Municipal Power Systems, “PUET Committee: Carbon Free
Technologies” (Los Alamos, October 20, 2021), https://ieefa.org/wp-content/uploads/2022/02/October-2021UAMPS-presentation.pdf.
xxxix UAMPS, “Amended Budget & Plan of Finance” (Los Alamos: Utah Associated Municipal Power
Systems, July 14, 2020), https://losalamos.legistar.com/LegislationDetail.aspx?ID=4614617&GUID=80F3BB19BE25-49F0-88CB-2B226422A101&Options=&Search=; M. V. Ramana, “Eyes Wide Shut: Problems with the Utah
Associated Municipal Power Systems Proposal to Construct NuScale Small Modular Nuclear Reactors,” Small
Modular Reactors (SMRs): News, Articles and Reports on Small Modular Nuclear Reactors (SMRs) (Portland, OR:
Oregon Physicians for Social Responsibility, September 2020),
https://www.oregonpsr.org/small_modular_reactors_smrs.
xl Douglas O. Hunter, “Why the World Is Watching Utah’s Carbon Free Power Project,” The Salt Lake
Tribune, November 23, 2021, https://www.sltrib.com/opinion/commentary/2021/11/23/douglas-o-hunter-why/.
xli Robert Walton, “Rising Steel Prices, Interest Rates Could Push NuScale Utah Project Cost to $100/MWh,but Support Remains,” Utility Dive, November 16, 2022, https://www.utilitydive.com/news/nuscale-nuclearreactor-smr-uamps-rising-steel-prices-interest-rates/636619/; Peter Behr, “Rising Costs Imperil Nation’s Leading
Small Reactor Project,” E&E News, December 14, 2022, https://www.eenews.net/articles/rising-costs-imperilnations-leading-small-reactor-project/.
xlii UAMPS, “Talking Points,” County of Los Alamos - Meeting of Board of Public Utilities on 1/11/2023 at
5:30 PM, January 2, 2023, https://losalamos.legistar.com/MeetingDetail.aspx?ID=1064272&GUID=89C48D4FF0CE-42D1-B04D-4719B2EE31E5&Options=info|&Search=.
xliii David Schlissel, “Southern Company’s Troubled Vogtle Nuclear Project” (Institute for Energy Economics
and Financial Analysis, January 2022), https://ieefa.org/wp-content/uploads/2022/01/Southern-CompanysTroubled-Vogtle-Nuclear-Project_January-2022.pdf.
xliv Benjamin K. Sovacool, Alex Gilbert, and Daniel Nugent, “Risk, Innovation, Electricity Infrastructure andConstruction Cost Overruns: Testing Six Hypotheses,” Energy 74 (September 1, 2014): 906–17,
https://doi.org/10.1016/j.energy.2014.07.070.
xlv Pete Danko, “Fluor (NYSE: FLR), after Raising $40M, Seeking More NuScale Investors,” Portland Business
Journal, May 11, 2021, https://www.bizjournals.com/portland/news/2021/05/11/nuscale-power-seekinginvestment.html.

10xlvi Debra K Robin, “Fluor Continues Management Shakeout to Boost Results,” Engineering News-Record,

May 30, 2019, https://www.enr.com/articles/46979-fluor-continues-management-shakeout.
xlvii Jose N. Reyes, “NuScale Response to NASEM Questionnaire,” Letter to National Academies of Sciences,
Engineering, and Medicine Committee, July 14, 2021, https://1library.net/document/yd27kl1g-nuscale-responseto-nasem-questionnaire.html.
xlviii GAO, “DOE Should Institutionalize Oversight Plans for Demonstrations of New Reactor Types”(Washington, D.C.: United States Government Accountability Office, September 15, 2022), 22,https://www.gao.gov/products/gao-22-105394.
xlix GAO, 17.
l William Freebairn, “NuScale Planning to Go Public Using SPAC Process: Financial Adviser,” S&P Global
Platts, December 8, 2021, https://www.spglobal.com/platts/en/market-insights/latest-news/electricpower/120821-nuscale-planning-to-go-public-using-spac-process-financial-adviser.
li Kevin Clark, “Japanese Venture Buys Large Stake in NuScale Power,” Power Engineering, April 4, 2022,
https://www.power-eng.com/nuclear/fluor-sells-equity-stake-in-nuclear-power-company-nuscale-power/.
lii NuScale, “Fluor-Held NuScale Equity Purchased by Japanese Partner,” News Releases (blog), April 4,2022, https://www.nuscalepower.com/en/news/press-releases/2022/fluor-held-nuscale-equity-purchased-byjapanese-partner.
liii Advisory Committee on Reactor Safeguards, “NuScale Area of Focus - Helical Tube Steam Generator
Design,” March 24, 2020.
liv Advisory Committee on Reactor Safeguards, 2.

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