Naked Nuclear

ABOUT THIS EPISODE

What keeps a nuclear power plant running safely after 50 years? Tighe Smith knows better than almost anyone. As Chief Nuclear Officer at Paragon Energy Solutions — now part of Mirion Technologies following a $585 million acquisition — Tighe has spent his career in nuclear instrumentation and control (I&C): the nervous system of every reactor.

In this episode, we get into what I&C actually does, why some of the control systems inside U.S. nuclear plants predate the transistor, how Paragon reverse-engineers obsolete circuit cards with 1970s components, and how they broker spare parts between 94* reactors across the country — 3,000 parts a year, same-day or next-day shipping. Plus: the workforce reality of digital upgrades, advanced reactor design, and a culture built on three P's and three C's.

WHAT YOU'LL LEARN

- What instrumentation and control (I&C) is and why it's the most invisible-but-critical system in any nuclear plant

- Why some U.S. reactor control systems still use technology from before the transistor was invented

- How Paragon reverse-engineers obsolete circuit cards — and why rotating a transistor 90 degrees can introduce failure modes

- The PEAKS program: how 3,000 parts move between 94 reactors every year

- Why nuclear plants carry $100 million in spare parts inventory (and why it's worth it)

- The analog vs. digital debate: why a digital upgrade only makes sense if you're planning to run a plant for 20+ more years

- How I&C changes for advanced reactors — simpler safety systems, new challenges

- Paragon's Three P's (Present, Persistent, Passionate) and Three C's (Competence, Commitment, Character)

CONNECT WITH PARAGON/MIRION

LinkedIn (Tighe Smith): Search "Tighe Smith Paragon Energy Solutions"

Paragon Energy Solutions (now Mirion Technologies): https://www.mirion.com/

Mirion Technologies LinkedIn: https://www.linkedin.com/company/mirion-technologies/

RESOURCES MENTIONED

- HIPS (Highly Integrated Protection System) — Paragon's FPGA-based digital safety platform

- Core Vision — Paragon's neutron monitoring product line

- PEAKS — Paragon's nuclear spare parts network program

- 10 CFR 50 — NRC domestic licensing requirements

- Three Mile Island accident and lessons for human-machine interface design

- NRC maintenance and testing requirements for nuclear facilities

JOIN THE NUCLEAR WORKFORCE

The nuclear industry is growing, and companies like Paragon/Mirion need engineers, technicians, and trades workers with the right skills and the right character.

Are you a skilled professional interested in nuclear? Nuclear Talent Scout connects candidates with nuclear employers.

Apply here: https://nucleartalentscout.com/apply/

ABOUT NAKED NUCLEAR

Naked Nuclear is the podcast that pulls back the curtain on the nuclear industry — no hype, no fear, just real conversations with the people doing the work. Hosted by Danielle Allen.

Website: www.nakednuclear.com

Mark Schneider accidentally became a nuclear professional at 17 when a sarcastic answer to a Navy recruiter — "only if you have nuclear power" — launched a 20-year career. He went on to serve as a nuclear electronics technician, make chief petty officer, earn his commission as a nuclear-powered limited-duty officer, and operate reactors on three submarines and an aircraft carrier.

Now he's the Chief Nuclear Officer at UBH Group, and his current mission is one of the most unusual in the industry: building Australia's nuclear workforce from the ground up. Because of AUKUS, Australia is getting nuclear-powered submarines for the first time and they need people who understand what that actually means.

What this conversation

- How a sarcastic teenager accidentally built a 20-year nuclear career in the U.S. Navy

- What it's like to operate reactors on nuclear submarines and aircraft carriers

- Why "a nuclear reactor that happens to submerge" is the same as any other reactor

- How AUKUS is creating one of the most unusual nuclear workforce challenges in the world

- What ISO 19443, NQA1, and 10 CFR 50 supply chain standards actually mean in practice

- Why the O-ring on a cooling pump matters as much as any major system

- AUKUS Submarine Partnership: https://www.defense.gov/News/Releases/Release/Article/3326875/

- ISO 19443 (nuclear supply chain quality management)

- NQA-1 (American Society of Mechanical Engineers nuclear quality assurance)

- 10 CFR 50 (NRC domestic licensing requirements for nuclear facilities)

Are you a skilled trades worker or veteran interested in a nuclear career? Nuclear Talent Scout matches candidates with nuclear employers — and the industry is hiring.

Apply here: https://forms.clickup.com/20124732/f/k651w-5551/4VA92A2B0QA0RJEHJB

Jonas Helwig is Swedish-born, French-passport-holding, and was living in Ukraine when the war started. He fled with his wife and their newborn daughter, ended up in Buenos Aires by accident, and his neighbor turned out to be a nuclear energy manufacturer.

Over dinner conversations with a pen and paper, they sketched out the N1, and Jonas joined the company. That's how Nuclearis Energy started.

In this episode, Jonas walks us through the N1 micromodular reactor: what it is, how it solves the efficiency problem that makes most microreactors uneconomical, why air-cooling changes where nuclear can go, how the design process started at the spent fuel and worked backwards, and what a "nuclear renaissance" actually means.

CONNECT WITH JONAS & NUCLEARIS

Jonas Helwig on LinkedIn: Search "Jonas Helwig Nuclearis"

Nuclearis Energy website: https://www.nuclearisenergy.com/

Nuclearis on X: Search @nuclearisenergy

Nuclearis on LinkedIn: https://www.linkedin.com/company/nuclearis-energy/

- Atucha Nuclear Power Plants (Argentina): https://www.iaea.org/PRIS/CountryStatistics/ReactorDetails.aspx?current=388

JOIN THE NUCLEAR WORKFORCE

Companies like Nuclearis are gearing up for major engineering hiring. And across the industry, the nuclear workforce shortage is real, the sector needs people now.

Nuclear Talent Scout connects skilled candidates with nuclear employers.

Apply here: https://forms.clickup.com/20124732/f/k651w-5551/4VA92A2B0QA0RJEHJB

ABOUT NAKED NUCLEAR

Naked Nuclear is the podcast that pulls back the curtain on the nuclear industry — no hype, no fear, just real conversations with the people doing the work. Hosted by Danielle Allen.

Website: www.nakednuclear.com

SNEAK PEAK!

Season 4 of Naked Nuclear is about the infrastructure underneath nuclear energy, the laws, regulations, economics, and institutions most people never think about. Ross Matzkin-Bridger is exactly the right person to open that conversation.

As Senior Director at the Nuclear Threat Initiative and a senior advisor at the Nuclear Scaling Initiative, Ross has spent 11 years in U.S. government bouncing between nuclear nonproliferation and energy policy. He grew up near reactors in Michigan and New Hampshire, lived in Japan, and has built his career on one question: how do we get all the benefits of nuclear energy without any of the weapons risks?

In this episode: the domestic and international guardrails keeping nuclear energy separate from nuclear weapons, the economics of building at scale, who the real decision-makers are, and a clear framework for evaluating the dozens of reactor designs competing for attention.

WHAT YOU'LL LEARN

- How the NRC, IAEA, and Nuclear Non-Proliferation Treaty (NPT) work together to keep nuclear energy peaceful

- Why the fuel in U.S. reactors (low-enriched uranium) is fundamentally different from weapons-usable material — and why that distinction matters

- Who decides which reactor technologies get built: government, industry, and communities

- Why the U.S. goal of quadrupling nuclear by 2050 requires more than just technology

- The "onesies and twosies" problem: why building at scale changes the economics entirely

- Ross's four-bin framework for evaluating reactor designs (and why spent fuel reprocessing lands in "Bin 4")

- When we can realistically expect new nuclear plants to come online

THE FOUR BINS FRAMEWORK

1. TRIED AND TRUE: Already deployed, licensed, producing electricity. First candidates for scaling.

2. ON THE CUSP: Based on proven technology with smart modifications. SMRs live here.

3. INTERESTING BUT SPECULATIVE: Real science, not yet ready for scaling. Sodium-cooled fast reactors, molten salt.

4. SCALING INHIBITORS: Technologies that introduce weapons-usable materials (plutonium) into the fuel cycle. Spent fuel reprocessing lands here.

CONNECT WITH ROSS & NSI

Nuclear Threat Initiative: https://www.nti.org/

Nuclear Scaling Initiative: https://www.nuclearscaling.org/

NTI on LinkedIn: https://www.linkedin.com/company/nuclear-threat-initiative/

NTI on Instagram: @nuclearthreatinitiative

NSI Reactor Selection Tool: Available at nuclearscaling.org, helps stakeholders compare reactor designs across security, economics, and deployment readiness criteria.

RESOURCES MENTIONED

- Nuclear Non-Proliferation Treaty (NPT): https://www.un.org/disarmament/wmd/nuclear/npt/

- International Atomic Energy Agency (IAEA): https://www.iaea.org/

- U.S. Nuclear Regulatory Commission (NRC): https://www.nrc.gov/

- NTI Nuclear Security Index: https://www.ntiindex.org/

- Clean Air Task Force: https://www.catf.us/

- Energy Futures Initiative Foundation: https://www.energyfuturesinitiative.org/

JOIN THE NUCLEAR WORKFORCE

A quadrupled nuclear sector means a much bigger workforce. Whether you're an engineer, a trades worker, or someone curious about nuclear careers — the industry is hiring.

Nuclear Talent Scout connects candidates with nuclear employers.

Apply here: https://forms.clickup.com/20124732/f/k651w-5551/4VA92A2B0QA0RJEHJB

Ed McGinnis said something in our last episode that's hard to shake: 96% of the energy in spent nuclear fuel has never been touched. The physics checks out. But what happens when countries actually try to get that energy back?

This After Pop digs into the history of nuclear fuel recycling, not the theory, but the track record. France, the UK, Japan. Staggering sums of money. Complicated results. And a 1977 executive order that changed everything.

We break down what PUREX actually does, why Jimmy Carter banned commercial reprocessing, and what any next-generation recycling technology (including Curio's NuCycle) would actually have to solve to change the equation.

• France's La Hague plant: running since 1976, processing 1,000+ tons of spent fuel per year, and saving roughly 18,000 metric tons of natural uranium. Also: a Court of Auditors estimate ranging from €16 billion to €58 billion in total program costs.
• The UK's Sellafield THORP: built for £1.8 billion, promised £500 million in profit, delivered £1 billion in losses, closed in 2018. Decommissioning costs are estimated at up to £250 billion and won't be finished until 2125.
• Japan's Rokkasho: supposed to open in 1997. It's 2026. Construction costs have hit ¥3.7 trillion (~$25 billion), with lifecycle costs projected above $100 billion. It has never processed a full ton of commercial fuel at capacity.
• PUREX: what it actually does, why it was designed the way it was (Manhattan Project-era, weapons-grade plutonium), and why producing a pure stream of separated plutonium is the source of the proliferation problem.
• India's 1974 Smiling Buddha test: where Carter's concern came from, and why it wasn't theoretical.
• The five things next-gen recycling has to solve: cost, proliferation resistance, regulation, waste, and public trust.

The numbers that matter:

• ~$85/lb: current uranium spot price
• ~$140/lb (~$360/kg): the price at which reprocessing starts to break even, per Harvard's Belfer Center
• 99 metric tons: France's current separated civilian plutonium stockpile
• 44.4 metric tons: Japan's separated plutonium (most of it sitting in France and the UK)
• 300 years vs. 100,000+ years: radiotoxicity timeline for recycled waste vs. direct disposal

Resources:

• Harvard Belfer Center, The Economics of Reprocessing vs. Direct Disposal of Spent Nuclear Fuel: https://www.belfercenter.org/publication/economics-reprocessing-vs-direct-disposal-spent-nuclear-fuel
• France's Court of Auditors report on nuclear costs (English summary via World Nuclear Association): https://world-nuclear.org/information-library/nuclear-fuel-cycle/fuel-recycling/processing-of-used-nuclear-fuel
• UK Nuclear Decommissioning Authority, Sellafield: https://www.gov.uk/government/organisations/nuclear-decommissioning-authority
• Japan Atomic Energy Commission, Rokkasho lifecycle cost estimate: https://www.jaec.go.jp/en/
• Jimmy Carter's Executive Order on Reprocessing (1977): https://www.nrc.gov/docs/ml1209/ML120960615.pdf
• IAEA, Proliferation resistance of nuclear fuel cycles: https://www.iaea.org/topics/nuclear-fuel-cycle

Imagine filling up your car at a gas station in Washington, DC, and heading toward Richmond. Twenty miles down the road, you pull over, call a tow truck, and scrap the car, with 96% of the fuel still in the tank. That's what we do with nuclear fuel in the United States right now.

Ed McGinnis is the CEO of Curio and a former senior official at the U.S. Department of Energy. He's spent decades in nuclear policy and energy security, and he's now building something that could change how we think about nuclear waste entirely. Spoiler: he doesn't even call it waste. He calls it "slightly used fuel."

In this episode, Ed breaks down why the U.S. stopped recycling nuclear fuel in the 1970s, what went wrong with the Cold War-era Purex process, and how Curio's NuCycle technology does it differently ... without ever separating pure plutonium. We get into the $50 billion Nuclear Waste Fund that was collected from ratepayers and spent on other things, why the DOE is now paying over a billion dollars a year in court-ordered damages, and how 90,000+ metric tons of used fuel sitting at reactor sites across the country is actually the largest above-ground energy reserve in the world.

Plus: Curio's planned recycling facility, bigger than a football stadium, processing more fuel than every other recycling facility on the planet combined, and the 3,000+ trades-based jobs it would create at around $125K a year for 60+ years.

Topics covered:

• Why only 3-4% of nuclear fuel is actually used — and 96% is still usable energy
• The difference between the Cold War Purex process and Curio's NuCycle technology
• President Carter's ban on fuel recycling and the $13+ billion in lost investments
• How recycling reduces radiotoxicity from 100,000+ years to about 300 years
• Curio's partnership with Oak Ridge National Laboratory since 2019
• The Nuclear Waste Policy Act, the $50 billion fund, and the billion-dollar-a-year lawsuit payouts
• Russia still providing 20%+ of U.S. nuclear fuel — and what that means for energy security
• Curio's planned facility: 4,000 metric tons per year, 3,000+ jobs, mostly trades
• Curio's own SMR and micro-reactor designs (TrueFuel)

Resources:

Learn more about CURIO: curio.energy

Jimmy Carter's Ruling on Reprocessing Spent Nuclear Fuel: https://www.nrc.gov/docs/ml1209/ML120960615.pdf

Dr. John Zino stood in front of a room of engineers, technicians, and career-changers and told them a nuclear reactor is "just boiling water." Jaws dropped. Really? That's it?

Well, yes. And also, that little word "just" is hiding one of the most elegant chains in all of engineering.

In this After Pop explainer, we follow a single uranium atom from the moment it splits to the moment your phone starts charging. Fission to heat. Heat to steam. Steam to a spinning shaft. Spinning shaft to electricity. Four conversions, one pinky-tip-sized fuel pellet, and a reactor design that gets safer by removing the parts that can break. We'll also answer the question everyone asks once they see the numbers: if the BWRX-300 makes 870 megawatts of heat, where do the other 570 go?

Bring your curiosity. No PhD required.

• The fuel chain, demystified. Pellet → fuel rod → assembly → core, and why the reactor core is really a very expensive water heater.
• BWR vs. PWR in plain English. Why a boiling water reactor uses one water loop while a pressurized water reactor uses two, and what the BWRX-300 gets to skip.
• The two numbers in the name. 870 MW thermal, 300 MW electrical, and why that gap is physics, not a flaw.
• How a turbine actually works. The garden-hose analogy, high- and low-pressure stages, and why the shaft has to spin at exactly 1,800 RPM on a 60 Hz grid.
• Faraday's 1831 trick. A magnet, some copper, and the moment motion becomes electricity.
• The Carnot limit. Why every thermal plant on Earth, coal and gas included, has to dump roughly two-thirds of its heat, and why that's why plants sit next to water.
• The BWRX-300's quiet superpower. Natural circulation and the passive isolation condenser. You can't break the pumps when the pumps aren't there.

• ~870 MWt / 300 MWe — total heat output vs. electricity delivered for the BWRX-300
• ~33–35% — typical thermal efficiency of a nuclear plant (roughly a third of the heat becomes power)
• ~7 grams ≈ 1 ton of coal — the energy in one uranium fuel pellet, about the size of your pinky tip
• 1,800 RPM at 60 Hz (US/Americas) / 1,500 RPM at 50 Hz (Europe, most of Asia) — turbine speed locked to grid frequency
• 1824 & 1831 — Carnot's limit on heat-to-work, and Faraday's law of induction. Still the foundation.

On the BWRX-300

• GE Vernova Hitachi — BWRX-300 Small Modular Reactor (design overview, natural circulation, isolation condenser): https://www.gevernova.com/nuclear/carbon-free-power/bwrx-300-small-modular-reactor
• U.S. NRC — BWRX-300 pre-application activities and topical reports: https://www.nrc.gov/reactors/new-reactors/advanced/who-were-working-with/pre-application-activities/bwrx-300
• World Nuclear Association — SMR Design Database, BWRX-300 detail: https://world-nuclear.org/information-library/nuclear-power-reactors/small-modular-reactors/small-modular-reactor-smr-design-database?detail=BWRX-300

On thermal efficiency, the Carnot limit & waste heat

• World Nuclear Association — Nuclear Power Reactors (thermal efficiency, MWt vs. MWe): https://world-nuclear.org/information-library/nuclear-fuel-cycle/nuclear-power-reactors/nuclear-power-reactors
• World Nuclear Association — Cooling Power Plants (why plants reject heat and sit near water): https://world-nuclear.org/information-library/current-and-future-generation/cooling-power-plants

On SMRs and the policy landscape

• DOE Office of Nuclear Energy — Advanced Small Modular Reactors: https://www.energy.gov/ne/advanced-small-modular-reactors-smrs
• DOE Office of Nuclear Energy — Generation III+ SMR Program (incl. TVA / Clinch River BWRX-300): https://www.energy.gov/ne/generation-iii-small-modular-reactor-program

What does it actually look like to spend nearly 40 years inside the nuclear industry, from submarine shielding to the Department of Energy to the cutting edge of small modular reactor design?Dr. John Zino is a Chief Consulting Engineer at GE Vernova Hitachi Nuclear Energy and an Associate Teaching Professor at NC State University. In this episode, he breaks down the BWRX-300 — a 10th-generation boiling water reactor that strips nuclear power down to its simplest form. No massive recirculation pumps. Natural circulation cooling. And the same proven fuel the industry has relied on for decades.We talk about why tech companies like Meta, Microsoft, and Google are suddenly interested in nuclear, how old coal sites are being converted for new reactors, and why the nuclear workforce could grow from 70,000 to half a million people in the next two decades.

Plus why you don't need a PhD to build a career in nuclear.If you're a nuclear professional looking for a new opportunity, fill out our TALENT FORM here!Additional Resources: GE Vernova Hitachi Nuclear Energy: https://nuclear.gevernova.com

BWRX-300 Overview:

https://nuclear.gevernova.com/small-modular-reactor

NC State Nuclear Engineering:

https://www.ne.ncsu.edu

Ontario Power Generation — Darlington New Nuclear: https://www.opg.com/powering-ontario/nuclear-power/darlington-new-nuclear

Cape Fear Community College Nuclear Technology Program:

https://cfcc.edu/directory/f77572817d963013b7cb18c1f2d2c994160a53d1/

What does it take to explain one of the most misunderstood technologies on Earth?

This Final Friday on Naked Nuclear, Danielle sits down with Nick Touran for a new Follow Them Friday episode.

Nick is the founder of What Is Nuclear, one of the internet’s most respected resources for understanding nuclear energy, reactor technology, fuel cycles, history, and policy in plain English. In a world drowning in hot takes and cold IQs, he built something useful.

We discuss Nick’s journey into nuclear engineering, how he built What Is Nuclear, why communication matters, and how advanced reactors differ through choices like coolants and moderators. We also get into regulation, licensing, innovation bottlenecks, and what may be next for nuclear in maritime applications.

If you’ve ever wanted nuclear explained clearly, or wondered where the industry is headed next, this is the episode.

• How Nick Touran got into nuclear engineering
• Why he created WhatIsNuclear.com
• Explaining reactors simply: coolants, moderators, and design choices
• Fast reactors vs thermal reactors
• Why licensing and regulation shape innovation
• Nuclear power for maritime shipping and industrial use
• The future of advanced reactors
• Why good science communication matters more than ever

Nick is helping lead a new maritime nuclear venture focused on the future of clean shipping and advanced nuclear deployment.

They’re seeking exceptional talent, including:

• Licensing Engineers
• Reactor Engineers
• Nuclear Scientists
• Regulatory Experts
• Advanced Reactor Talent

To be considered, complete the qualified candidate form here:

Check out Nick's Youtube Page here:

https://www.youtube.com/@whatisnuclear

At 2:13 AM in Waynesboro, Georgia, crews were already deep into a process they couldn’t stop.

For 41 continuous hours, concrete flowed into the basemat of Vogtle Unit 4, the foundation that would anchor one of the newest nuclear reactors in the United States.

This episode breaks down:

• What a nuclear basemat actually is
• Why concrete is part of the safety system
• The physics of heat, cracking, and radiation shielding
• The choreography required to keep a 41-hour pour alive
• And why this moment marks the point where a power plant becomes real

Watch: Vogtle Unit 4 Basemat Pour (Timelapse)

If you only watch one thing, make it this.
It’s the closest you’ll get to seeing thousands of people collectively refuse to mess up.

https://www.youtube.com/watch?v=3UhwCOzqY5w&t=102s

The basemat is a massive reinforced concrete foundation that supports:

• Reactor vessel
• Containment structure
• Primary systems

Once poured, there’s no going back. This is the “point of no return” in construction.

• Radiation shielding: absorbs gamma rays and slows neutrons
• Structural stability: supports extreme loads and seismic forces
• Containment support: part of the safety barrier system

Concrete generates heat as it cures.

Too hot, it weakens
Too cold too fast, it cracks

Mass pours require careful thermal control to avoid internal stress failures.

Stopping mid-pour can create weak joints in the structure.

Further Reading

• World Nuclear News – Vogtle AP1000 construction
  https://world-nuclear-news.org/Articles/Construction-underway-of-second-Vogtle-AP1000
• Local coverage of the 41-hour pour
  https://www.thetruecitizen.com/articles/progress-marked-by-41-hour-concrete-pour/

• NRC Design Certification (AP1000 structural details)
  https://www.nrc.gov/docs/ML1209/ML12094A053.pdf
• NRC Structural/Engineering Safety Review
  https://www.nrc.gov/docs/ML1419/ML14198A460.pdf

• U.S. Department of Energy (OSTI) – Concrete shielding & materials
  https://www.osti.gov/servlets/purl/4640326
• Mass concrete & thermal behavior (preprint)
  https://www.preprints.org/frontend/manuscript/f170f30200edb1f874eadb833a6ab966/download_pub

• IAEA – Radiation shielding principles
  https://www.iaea.org/publications
• American Concrete Institute (ACI) – Mass concrete & thermal control
  https://www.concrete.org
• NRC Standard Review Plan (structural & seismic design)
  https://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr0800/