The Probabilistic Risk Assessment (PRA) Engineer reports directly to the Risk Assessment Manager. The PRA Engineer will work with the Nuclear Risk Assessment team and is responsible for performing PRA and severe accident analysis for the Natrium reactor design. The PRA Engineer is primarily responsible for internal and external PRA work to be performed in coordination with deterministic and consequence safety analysis and other engineering disciplines to design a reliable and safe plant. Additionally, the PRA Engineer will use developed PRA models to provide risk information such as importance measures and changes in risk metrics to inform design and licensing decisions. Other engineering activities include, but are not limited to, contributing to the development of computational methodologies and models, participating in hazard analysis, participating in Phenomena Identification and Ranking Table (PIRT) exercises, and participating to Structures, Systems, and Components (SSC) classification, Licensing Basis Events (LBE) selection, and Defense-in-Depth (DID) Evaluations. The PRA Engineer will be interacting with other groups via interviews, emails, meetings, and other avenues to develop the risk models and the position requires sound written and verbal communication skills.
This position requires an understanding of PRA principles and preferably familiarity with the ASME/ANS PRA standard. While this position requires knowledge of sodium fast reactor technology, this knowledge can be obtained on the job through various in-house training workshops and interaction.

Responsibilities
Contribute to PRA work performed inside and outside of TerraPower in coordination with plant design, deterministic and consequence safety analysis, and other disciplines.
Ensure that the PRA is appropriate and used for the reactor design and within regulatory requirements, guidance, and standards such as risk-informed performance-based technology guidance for Non-Light Water Reactors (NEI 18-04) and ASME/ANS Non-Light Water PRA standard.
Participate in the development of planning and schedule for PRA related activities.
Provide technical guidance to engineers and managers on reliability and various PRA-related topics.
Participate in PRA peer reviews.
Work on the development of event and fault trees, in-vessel radiological transport models, containment transport models, and mechanistic radiological release categories for PRA models.
Work with an interdisciplinary team of engineers to establish core and reactor SSC functional, reliability, performance, safety, and quality requirements as well as support the overall design.
Establish and maintain documentation of model development and analysis results.
Perform engineering reviews of analyses and other engineering design media.
Develop containment fault trees and event trees to reflect most up to date design using CAFTA.
Group similar source terms for assignment to event sequence end states.
Perform risk integration using the PRA model to report risk metrics and importance measures.
Perform focused PRA analysis to support trade studies.
Perform hand calculations using first principles to assess and validate more complex models for system performance, containment performance, and radiological consequences.
Prepare topical reports describing PRA methods and analytical results for customers and regulators.
Deliver presentations for internal management and external customers and regulators.
Key Qualifications and Skills
B.S., or M.S. in nuclear, mechanical, electrical, or aerospace engineering (or similar)
Three years or more of experience in Probabilistic Risk Assessment
Knowledgeable of PRA principles and familiar with the ASME/ANS Non-Light Water PRA standard.
Knowledge on risk-informed performance-based regulations and applications.
Knowledgeable of PRA fundamentals in data, human reliability, accident analysis, severe accidents, and source terms assessments.
Experience with PRA software: CAFTA in particular; SAPHIRE, Risk Spectrum, or other similar software still considered valuable.
Experience with performing assessments using codes such as GOTHIC, MELCOR, RADTRAD, or similar tools is a plus.
Demonstrated technical writing and communication skills.
Experience with sodium cooled reactors or other advanced reactors preferred.
Fluent in spoken and written English language.
A broad understanding of the various engineering disciplines and how they interrelate in the design of a Nuclear Power Plant.
High degree of trust, integrity, open communication, respect for others, and teamwork.