Principal Nuclear Engineer
for section headings. Use - for any list of duties/requirements/benefits, and
for prose.
We need to preserve all substantive information, not invent or summarize away detail. Remove boilerplate: cookie/navigation/legal/EEO/equal-opportunity/scam-warning boilerplate, duplicated lines, and application instructions. So we need to strip out the equal opportunity employer paragraph, export controls note, contact email, etc. Also remove "About Radiant" maybe? The instruction: do NOT repeat the job title as a heading (the page already shows it) and do NOT put Job ID / requisition numbers as headings — fold minor metadata into a short
or drop it. The "About Radiant" is company description; is that substantive? It's about the company, not the role. Might be considered boilerplate? It's not about the role but could be considered background. The instruction says preserve ALL substantive information; do NOT invent or summarize away detail. The "About Radiant" is substantive about company. Should we keep? It's not a section heading; we could include as a
before sections. The instruction: Use
for section headings (e.g. About the role, Responsibilities, Requirements, Qualifications, Skills, Benefits, Pay, Schedule). So we can have a heading "About the role". The "About Radiant" could be a paragraph before that. It's not a heading; we can just put it as a
. That seems okay.
We need to remove duplicated lines. There's some duplication: "Total Compensation And Benefits" paragraph repeats some of benefits. We'll need to keep info but avoid duplication. We'll synthesize but not summarize away detail. We need to preserve all substantive info; we can combine similar info but not lose details. Might be okay to keep both but avoid exact duplicate sentences. Let's extract.
Company description: "Radiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. The company’s first reactor, Kaleidos, is a 1-megawatt, fail-safe microreactor that can be transported anywhere power is needed and run for up to 5 years without refueling. Portable nuclear power with rapid-deploy capability can replace similar-sized diesel generators and provide critical asset support for hospitals, data centers, remote sites, and military bases. Radiant’s unique, practical approach to nuclear development leverages modern software engineering to rapidly deliver safe, factory-built microreactors that use existing, well-qualified materials. Founded in 2020, Radiant is on track to test its first reactor at the Idaho National Laboratory this summer, with initial customer deliveries beginning in 2028."
About the role: paragraph after "About The Role": "Radiant is seeking a Principal Nuclear Engineer to lead the interdisciplinary nuclear engineering work supporting Kaleidos. This role combines people leadership with hands-on technical ownership across core physics, neutron and radiation transport, shielding, activation and dose, thermal-hydraulics, safety analysis, instrumentation and controls, operations, and regulatory evaluations. You will guide work from requirements and early design trades through analysis, verification and validation, testing, and regulatory documentation. The ideal candidate brings deep expertise in neutron transport and Monte Carlo methods, along with the judgment to translate complex analysis into practical reactor design and operational decisions."
Responsibilities & Duties: list of bullet points (they are sentences separated by periods). We need to turn into
- . We'll need to preserve each duty.
Let's list them:
- Lead an interdisciplinary team working across reactor physics, core performance, shielding, dose and activation, thermal-hydraulics, safety analysis, I&C, and operations.
- Establish technical priorities, project plans, resource needs, and clear ownership across the nuclear engineering organization.
- Serve as a technical authority for neutron and radiation transport and Monte Carlo simulation methods.
- Own nuclear engineering projects from requirements capture and design iteration through model development, analysis, technical review, and final documentation.
- Guide analyses of criticality, reactivity control, shutdown margin, power distribution, depletion, temperature feedback, radiation transport, dose, activation, and shielding performance.
- Translate analytical results into actionable requirements and design decisions affecting the core, shielding, control systems, instrumentation, fluid systems, and structures.
- Establish technically rigorous practices for model verification and validation, peer review, configuration control, uncertainty evaluation, and documentation.
- Collaborate with reactor systems, thermal, mechanical, electrical, test, operations, safety, and regulatory teams to resolve multidisciplinary design challenges.
- Translate nuclear standards and regulatory requirements into analysis plans, design criteria, calculation packages, and verification activities.
- Support reactor testing and startup by defining analysis needs, instrumentation requirements, acceptance criteria, and methods for comparing predicted and measured performance.
- Identify technical risks, drive complex problems through closure, and communicate decisions and recommendations to engineering teams and company leadership.
- Mentor engineers through technical guidance, actionable feedback, and regular coaching.
Required Qualifications & Skills: list:
- Bachelor’s degree in nuclear engineering or a related technical discipline from an accredited institution.
- 9+ years of relevant nuclear engineering experience across reactor design, analysis, testing, licensing, safety, or operations.
- Demonstrated experience leading complex nuclear engineering projects and multidisciplinary technical teams.
- Experience hiring, managing, mentoring, or technically leading nuclear engineers.
- Deep knowledge of neutron transport theory, Monte Carlo simulation methods, nuclear data, and statistical convergence.
- Professional experience developing and applying MCNP, OpenMC, or comparable neutron and radiation transport models.
- Strong understanding of criticality, reactivity coefficients, depletion, power distribution, shutdown margin, radiation transport, and uncertainty analysis.
- Experience translating analysis into reactor design decisions, technical requirements, safety conclusions, or regulatory documentation.
- Familiarity with model verification and validation, configuration control, peer review, and nuclear software quality practices.
- Strong written and verbal communication skills, including the ability to explain complex analyses, assumptions, uncertainties, and technical conclusions.
Preferred Qualifications & Skills:
- Master’s degree or Ph.D. in nuclear engineering or a related discipline.
- Experience with high-temperature gas-cooled reactors, microreactors, advanced reactors, or first-of-a-kind nuclear systems.
- Experience with SCALE, Serpent, Shift, Griffin, MOOSE-based applications, or similar analysis tools.
- Proficiency with Python or another language used for simulation automation and data post-processing.
- Experience with coupled neutronics and thermal-hydraulics or other multiphysics analyses.
- Familiarity with DOE authorization, NRC licensing, nuclear codes and standards, or regulatory safety analysis.
- Experience supporting reactor testing, commissioning, startup, or operational readiness.
Additional Requirements:
- Willing to support extended hours when needed to meet critical program milestones.
- Must work 100% onsite at Radiant’s El Segundo headquarters.
Benefits And Perks:
- Stock: Substantial incentive stock plan for all full-time employees.
- Medical: 100% up to base silver level plan for employee + 50% dependents, offers up to Platinum plans.
- One Medical: Sponsored memberships for employees and their dependents.
- Vision: 100% top tier plan coverage + 50% for dependents.
- Dental: 100% top tier plan coverage, orthodontia extra, 50% for dependents.
- Voluntary life, accident, hospital, critical illness, commuter and FSA/HSA are offered as employee contributed benefits.
- 8-weeks of paid parental leave for all parents. Additional paid pregnancy leave for CA employees.
- Daily catered lunch.
- Free snacks and drinks.
- Flexible PTO policy.
- Remote workday allocation.
- Company and team-bonding events, happy hours and in-person camaraderie.
- Beautiful El Segundo headquarters close to the Pacific Ocean.
Total Compensation And Benefits paragraph: "Radiant compensates people for impact and invests in those who continue to raise the bar. Radiant’s new hire compensation package includes base salary, substantial equity grants, and comprehensive health benefits. Total compensation and level are determined through a rigorous evaluation of interview performance, experience, education, and qualifications, and are designed to support continued growth as scope, responsibility, and impact expand at Radiant. The best of today’s advanced reactor builders don’t wait for job postings. They join the winning team. If that’s you, contact us directly for immediate opportunities: recruiting@radiantnuclear.com."
We need to remove application instructions (contact email) and EEO boilerplate. Also remove "We are an equal opportunity employer..." paragraph. Also remove export controls line. Also remove "This position involves access to technology that is subject to U.S. export controls..." etc.
We need to keep compensation range: "Compensation Range: $195,713 - $262,500". That's Pay section.
We need to decide sections: About the role (we already have a paragraph about role). Could also include About Radiant as a preceding paragraph but not a heading. The instruction says use
for section headings (e.g. About the role, Responsibilities, Requirements, Qualifications, Skills, Benefits, Pay, Schedule). It doesn't forbid other headings, but we should follow that pattern. We'll include headings for sections we have content: About the role, Responsibilities, Requirements, Qualifications, Skills, Benefits, Pay. Possibly also "Additional Requirements" could be folded into Requirements or Qualifications? It's about work location and hours; could be part of Requirements. We'll treat as part of Requirements (maybe as a sub-list). But we need to preserve all info. Could create a section "Requirements" for mandatory qualifications (including education, experience, etc.) and separate "Preferred Qualifications". The instruction lists Requirements and Qualifications as separate possible headings. We'll follow: Requirements
for mandatory qualifications (Bachelor's, 9+ years, leading projects, etc.) and Qualifications
for preferred qualifications (Master's/PhD, etc.). Skills could be separate but we already have skills within those lists. Could combine skills into those sections. But we have a separate "Skills" heading possible. However the posting lumps skills with qualifications. To avoid thin sections, we can combine skills into Requirements and Qualifications sections. The instruction: Prefer a few substantive sections over many thin ones. So we can have sections: About the role, Responsibilities, Requirements, Qualifications, Benefits, Pay. That's six sections.
We need to ensure we don't create a Schedule section.
Now we need to format.
We'll start with a
for company description (About Radiant). Then
About the role
with paragraph.
Then Responsibilities
with - ... each duty.
Then
Requirements
with - for mandatory qualifications (including Bachelor's
for prose. We need to preserve all substantive information, not invent or summarize away detail. Remove boilerplate: cookie/navigation/legal/EEO/equal-opportunity/scam-warning boilerplate, duplicated lines, and application instructions. So we need to strip out the equal opportunity employer paragraph, export controls note, contact email, etc. Also remove "About Radiant" maybe? The instruction: do NOT repeat the job title as a heading (the page already shows it) and do NOT put Job ID / requisition numbers as headings — fold minor metadata into a short
or drop it. The "About Radiant" is company description; is that substantive? It's about the company, not the role. Might be considered boilerplate? It's not about the role but could be considered background. The instruction says preserve ALL substantive information; do NOT invent or summarize away detail. The "About Radiant" is substantive about company. Should we keep? It's not a section heading; we could include as a
before sections. The instruction: Use
for section headings (e.g. About the role, Responsibilities, Requirements, Qualifications, Skills, Benefits, Pay, Schedule). So we can have a heading "About the role". The "About Radiant" could be a paragraph before that. It's not a heading; we can just put it as a
. That seems okay. We need to remove duplicated lines. There's some duplication: "Total Compensation And Benefits" paragraph repeats some of benefits. We'll need to keep info but avoid duplication. We'll synthesize but not summarize away detail. We need to preserve all substantive info; we can combine similar info but not lose details. Might be okay to keep both but avoid exact duplicate sentences. Let's extract. Company description: "Radiant is an El Segundo, CA-based startup building the world’s first mass-produced, portable nuclear microreactors. The company’s first reactor, Kaleidos, is a 1-megawatt, fail-safe microreactor that can be transported anywhere power is needed and run for up to 5 years without refueling. Portable nuclear power with rapid-deploy capability can replace similar-sized diesel generators and provide critical asset support for hospitals, data centers, remote sites, and military bases. Radiant’s unique, practical approach to nuclear development leverages modern software engineering to rapidly deliver safe, factory-built microreactors that use existing, well-qualified materials. Founded in 2020, Radiant is on track to test its first reactor at the Idaho National Laboratory this summer, with initial customer deliveries beginning in 2028." About the role: paragraph after "About The Role": "Radiant is seeking a Principal Nuclear Engineer to lead the interdisciplinary nuclear engineering work supporting Kaleidos. This role combines people leadership with hands-on technical ownership across core physics, neutron and radiation transport, shielding, activation and dose, thermal-hydraulics, safety analysis, instrumentation and controls, operations, and regulatory evaluations. You will guide work from requirements and early design trades through analysis, verification and validation, testing, and regulatory documentation. The ideal candidate brings deep expertise in neutron transport and Monte Carlo methods, along with the judgment to translate complex analysis into practical reactor design and operational decisions." Responsibilities & Duties: list of bullet points (they are sentences separated by periods). We need to turn into
- . We'll need to preserve each duty.
Let's list them:
- Lead an interdisciplinary team working across reactor physics, core performance, shielding, dose and activation, thermal-hydraulics, safety analysis, I&C, and operations.
- Establish technical priorities, project plans, resource needs, and clear ownership across the nuclear engineering organization.
- Serve as a technical authority for neutron and radiation transport and Monte Carlo simulation methods.
- Own nuclear engineering projects from requirements capture and design iteration through model development, analysis, technical review, and final documentation.
- Guide analyses of criticality, reactivity control, shutdown margin, power distribution, depletion, temperature feedback, radiation transport, dose, activation, and shielding performance.
- Translate analytical results into actionable requirements and design decisions affecting the core, shielding, control systems, instrumentation, fluid systems, and structures.
- Establish technically rigorous practices for model verification and validation, peer review, configuration control, uncertainty evaluation, and documentation.
- Collaborate with reactor systems, thermal, mechanical, electrical, test, operations, safety, and regulatory teams to resolve multidisciplinary design challenges.
- Translate nuclear standards and regulatory requirements into analysis plans, design criteria, calculation packages, and verification activities.
- Support reactor testing and startup by defining analysis needs, instrumentation requirements, acceptance criteria, and methods for comparing predicted and measured performance.
- Identify technical risks, drive complex problems through closure, and communicate decisions and recommendations to engineering teams and company leadership.
- Mentor engineers through technical guidance, actionable feedback, and regular coaching.
Required Qualifications & Skills: list:
- Bachelor’s degree in nuclear engineering or a related technical discipline from an accredited institution.
- 9+ years of relevant nuclear engineering experience across reactor design, analysis, testing, licensing, safety, or operations.
- Demonstrated experience leading complex nuclear engineering projects and multidisciplinary technical teams.
- Experience hiring, managing, mentoring, or technically leading nuclear engineers.
- Deep knowledge of neutron transport theory, Monte Carlo simulation methods, nuclear data, and statistical convergence.
- Professional experience developing and applying MCNP, OpenMC, or comparable neutron and radiation transport models.
- Strong understanding of criticality, reactivity coefficients, depletion, power distribution, shutdown margin, radiation transport, and uncertainty analysis.
- Experience translating analysis into reactor design decisions, technical requirements, safety conclusions, or regulatory documentation.
- Familiarity with model verification and validation, configuration control, peer review, and nuclear software quality practices.
- Strong written and verbal communication skills, including the ability to explain complex analyses, assumptions, uncertainties, and technical conclusions.
Preferred Qualifications & Skills:
- Master’s degree or Ph.D. in nuclear engineering or a related discipline.
- Experience with high-temperature gas-cooled reactors, microreactors, advanced reactors, or first-of-a-kind nuclear systems.
- Experience with SCALE, Serpent, Shift, Griffin, MOOSE-based applications, or similar analysis tools.
- Proficiency with Python or another language used for simulation automation and data post-processing.
- Experience with coupled neutronics and thermal-hydraulics or other multiphysics analyses.
- Familiarity with DOE authorization, NRC licensing, nuclear codes and standards, or regulatory safety analysis.
- Experience supporting reactor testing, commissioning, startup, or operational readiness.
Additional Requirements:
- Willing to support extended hours when needed to meet critical program milestones.
- Must work 100% onsite at Radiant’s El Segundo headquarters.
Benefits And Perks:
- Stock: Substantial incentive stock plan for all full-time employees.
- Medical: 100% up to base silver level plan for employee + 50% dependents, offers up to Platinum plans.
- One Medical: Sponsored memberships for employees and their dependents.
- Vision: 100% top tier plan coverage + 50% for dependents.
- Dental: 100% top tier plan coverage, orthodontia extra, 50% for dependents.
- Voluntary life, accident, hospital, critical illness, commuter and FSA/HSA are offered as employee contributed benefits.
- 8-weeks of paid parental leave for all parents. Additional paid pregnancy leave for CA employees.
- Daily catered lunch.
- Free snacks and drinks.
- Flexible PTO policy.
- Remote workday allocation.
- Company and team-bonding events, happy hours and in-person camaraderie.
- Beautiful El Segundo headquarters close to the Pacific Ocean.
Total Compensation And Benefits paragraph: "Radiant compensates people for impact and invests in those who continue to raise the bar. Radiant’s new hire compensation package includes base salary, substantial equity grants, and comprehensive health benefits. Total compensation and level are determined through a rigorous evaluation of interview performance, experience, education, and qualifications, and are designed to support continued growth as scope, responsibility, and impact expand at Radiant. The best of today’s advanced reactor builders don’t wait for job postings. They join the winning team. If that’s you, contact us directly for immediate opportunities: recruiting@radiantnuclear.com."
We need to remove application instructions (contact email) and EEO boilerplate. Also remove "We are an equal opportunity employer..." paragraph. Also remove export controls line. Also remove "This position involves access to technology that is subject to U.S. export controls..." etc.
We need to keep compensation range: "Compensation Range: $195,713 - $262,500". That's Pay section.
We need to decide sections: About the role (we already have a paragraph about role). Could also include About Radiant as a preceding paragraph but not a heading. The instruction says use
for section headings (e.g. About the role, Responsibilities, Requirements, Qualifications, Skills, Benefits, Pay, Schedule). It doesn't forbid other headings, but we should follow that pattern. We'll include headings for sections we have content: About the role, Responsibilities, Requirements, Qualifications, Skills, Benefits, Pay. Possibly also "Additional Requirements" could be folded into Requirements or Qualifications? It's about work location and hours; could be part of Requirements. We'll treat as part of Requirements (maybe as a sub-list). But we need to preserve all info. Could create a section "Requirements" for mandatory qualifications (including education, experience, etc.) and separate "Preferred Qualifications". The instruction lists Requirements and Qualifications as separate possible headings. We'll follow:
Requirements
for mandatory qualifications (Bachelor's, 9+ years, leading projects, etc.) andQualifications
for preferred qualifications (Master's/PhD, etc.). Skills could be separate but we already have skills within those lists. Could combine skills into those sections. But we have a separate "Skills" heading possible. However the posting lumps skills with qualifications. To avoid thin sections, we can combine skills into Requirements and Qualifications sections. The instruction: Prefer a few substantive sections over many thin ones. So we can have sections: About the role, Responsibilities, Requirements, Qualifications, Benefits, Pay. That's six sections. We need to ensure we don't create a Schedule section. Now we need to format. We'll start with afor company description (About Radiant). Then
About the role
with paragraph. ThenResponsibilities
with- ... each duty.
Then
Requirements
with- for mandatory qualifications (including Bachelor's
- ... each duty.
Then