Thermal-Hydraulics Engineer

Ocean Atomics

2d•$95,000 - $220,000

About The Position

Ocean Atomics is an American company designing, licensing, and assembling a standardized nuclear electric power plant and the surrounding support systems for maritime applications. We will install these plants on any vessel built to our nuclear-ready standards, and will provide end-to-end sustainment in our planned nuclear lifecycle dockyard. We will help develop the licensed operators to unlock this new capability for your energy intensive application at sea. To move fast and to lead the creation of this new market, we are leveraging the compact, proven systems enabled by water-cooled reactors. Our mission Scale nuclear energy. Power generations. Our vision A maritime commons thriving with abundant, economical, modern, and safe nuclear-powered activity — built, serviced, and staffed by re-industrialized American shipyards and people. Role Summary As Thermal-Hydraulics Engineer, you design and analyze coolant flow through the reactor core and primary systems, characterizing pressure drop, flow distribution, mixing, and heat transfer to keep core cooling margins intact across the full range of operating conditions. Your work answers a question no land-based reactor has to ask: how flow distribution, natural circulation, and two-phase behavior hold up when the plant is heeling, trimming, and rolling with the ship beneath it. You partner with the testing team to prioritize test campaigns and feed the resulting data back into the models that set our thermal margins. This is a role we're hiring at multiple levels (L1 through L4). The work is shared across levels; scope and accountability scale with experience. This work suits someone who treats a model's uncertainty band as part of the answer, not a footnote to it, and who wants to know exactly how a wave changes what a coolant channel does.

Requirements

Bachelor's degree in nuclear, mechanical, or related engineering discipline, or equivalent practical experience.
Direct experience with thermal-hydraulic design or analysis of reactor core or primary system components.
Working knowledge of two-phase flow, subchannel analysis, and thermal margin methods (e.g., DNBR).
Proficiency with thermal-hydraulic and/or CFD codes (COBRA, VIPRE, STAR-CCM+, or equivalent).
Experience integrating experimental or test data into analytical models — validating, calibrating, benchmarking.
Early-career engineers with thermal-hydraulic analysis exposure through internships, research, or early-career roles in the nuclear industry (for L1-L2).
Have led at least one complete thermal-hydraulic analysis cycle through design review, in commercial nuclear, naval reactors, or comparable regulated environments (for L3-L4).

Nice To Haves

Background in naval architecture, marine engineering, or vessel-borne system design.
Experience with first-of-a-kind reactor designs or small modular reactor (SMR) programs.
Advanced degree in nuclear or mechanical engineering.

Responsibilities

Design and analyze coolant flow through the core and primary systems, characterizing pressure drop, flow distribution, mixing, and heat transfer against thermal margins across normal, transient, and casualty conditions.
Develop and refine thermal-hydraulic models and correlations (subchannel, system, and CFD analyses) that capture how ship motions and dynamic loading change flow distribution and natural circulation relative to a fixed-foundation reactor.
Establish thermal margins and operating limits (DNBR, flow-induced effects, void fraction) and feed results into core design and safety analyses.
Partner with the testing team to prioritize test campaigns, define instrumentation and test conditions, and target the data that most reduces uncertainty in the design models.
Incorporate test data into analytical models — validating, calibrating, and benchmarking — to close the gap between predicted and measured thermal-hydraulic performance.
Coordinate with our core mechanical, fuels, and structural teams to keep thermal-hydraulic assumptions aligned with mechanical design and neutronic requirements.
Lead system-level decisions on thermal-hydraulic design basis and correlation selection (at L3-L4).
Mentor newer engineers and review their analyses (at L3-L4).
Interface directly with our regulatory team on NRC-facing thermal-hydraulic documentation (at L3-L4).
Drive cross-team trade studies spanning thermal-hydraulics, fuels, and structural domains (at L3-L4).