Mission Support and Test Services, LLC

Senior Engineer - Nuclear Assurance

Posted Date 4 weeks ago(11/13/2023 5:47 PM)
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Mission Support and Test Services, LLC (MSTS) manages and operates the Nevada National Security Site (NNSS) for the U.S. National Nuclear Security Administration (NNSA).  Our MISSION is to help ensure the security of the United States and its allies by providing high-hazard experimentation and incident response capabilities through operations, engineering, education, field, and integration services and by acting as environmental stewards to the Site’s Cold War legacy.  Our VISION is to be the user site of choice for large-scale, high-hazard, national security experimentation, with premier facilities and capabilities below ground, on the ground, and in the air. (See NNSS.gov for our unique capabilities.) Our 2,750+ professional, craft, and support employees are called upon to innovate, collaborate, and deliver on some of the more difficult nuclear security challenges facing the world today.  In this environment, the best ideas need to be voiced and every opinion matters.  As such, MSTS places great value on Diversity, Equity, and Inclusion and is committed to a diverse and equitable workforce, with an inclusive culture that values and celebrates the diversity of our people, talents, ideas, and perspectives.

  • MSTS offers our full-time employees highly competitive salaries and benefits packages including medical, dental, and vision; both a pension and a 401k; paid time off and 96 hours of paid holidays; relocation (if located more than 75 miles from work location); tuition assistance and reimbursement; and more.  
  • MSTS is a limited liability company consisting of Honeywell International Inc. (Honeywell), Jacobs Engineering Group Inc. (Jacobs), and HII Nuclear Inc.


The Senior Engineer (Nuclear Criticality and Accident Analyst) in the Nuclear Assurance Directorate will be responsible for the development of Hazard Analysis, Documented Safety Analysis and Technical Safety Requirement Changes, as well as performing accident analysis calculations. The Senior Engineer will be assigned a project that they are expected to be able to complete with minor support, while mentoring entry level engineers.


Key Responsibilities

  • Support the performance of nuclear safety evaluations and analyses. These analytical tasks include the performance of hazards/accident analyses, hazard categorizations, Documented Safety Analyses (DSAs) and Technical Safety Requirements (TSRs), and the development/maintenance of NNSS nuclear facility Criticality and Accident Analyses.

  • Provide support in criticality and accident analysis techniques to improve and maintain the integrity and quality of the NNSS Safety Basis.

  • Perform analytical tasks including the performance of hazards/accident analyses to derive hazard controls and the development of other documentation such as descriptions of safety management programs (SMPs) and associated specific administrative controls (SACs) for the completion of Documented Safety Analysis (DSAs) and Technical Safety Requirements (TSRs).

  • Participate in detailed technical review of Safety Basis documents, procedures, supporting drawings, calculations, and documents to ensure accuracy, completeness, and format suitability for compliance with DOE directives and standards.

  • Interface with U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office (NNSA/NFO), internal, and external stakeholders to resolve technical and compliance issues and to assure that Nuclear Assurance performs its assigned functions in an integrated and compliant manner.

  • Support the initial and final hazard categorization of high hazard and other facilities or activities that utilize or stage radioactive materials.

  • Perform computer‑related activities such as preparing and analyzing data. Conduct modeling and calculations with nuclear safety software to support the completion of DSAs and Criticality Safety Evaluations (CSEs).

  • Perform technical research and assists with gathering data needed by engineers and safety analysts.

  • Devise solutions to highly complex technical problems of broad scope. Solutions may require resolving conflicting customer expectations and safety basis requirements, utilizing unconventional approaches and integration.

  • Generate and maintain Nuclear Safety procedures and implements improvements to nuclear safety business processes.

  • Complete Unreviewed Safety Question (USQ) reviews.

  • Conduct Management Assessments of nuclear safety activities.

  • Support field programs and performs related work as assigned by the supervisor.

  • Perform related work as assigned by lead analysts and/or supervisor.


  • Bachelor’s degree in an engineering program accredited by the Accreditation Board for Engineering
    and Technology (ABET) required for Civil, Mechanical and Electrical engineering degrees;
    • Or, Calculus-based STEM bachelor’s degree in engineering;
    • Or, for Architects, Certification from the National Council or Architectural Registration Board
    • Or Professional Engineer license
  • Plus at least 5 years’ relevant experience. Skill building experience must demonstrate either deeper technical specialization or additional cross-disciplinary knowledge. Graduate research experience may be recognized.
  • Degree in Mechanical, Nuclear, Chemical, or Industrial Engineering preferred.
  • Demonstrated technical knowledge of calculations, and applications of engineering methods. Applied knowledge of nuclear safety software, such as Monte Carlo N-Particle Transport (MCNP), MELCOR Accident Consequence Code System 2 (MACCS2) and BlastX is desirable.
  • Knowledge of governing Department of Energy (DOE) regulations, requirements, and guidance for development, implementation, and maintenance of nuclear safety programs and safety basis documents.
  • Strong working level of knowledge of Code of Federal Regulations (CFR) 10 CFR 830, subpart B; DOE-STD-1027-92; DOE-STD-1189-2008; DOE-STD-3009-2014; DOE-STD-3007-2007; DOE-HDBK-3010-94; DOE O 420.1C; DOE G 420.1-1; DOE G 420.1-2; DOE G 423.1-1; and DOE G 424.1.-1B and other applicable DOE directives and ANSI/ANS-8 series standards.
  • Must possess planning/organizing skills and initiative.
  • Must possess interpersonal communication skills to deal with contacts in an effective, positive, and professional manner.
  • Must be able to work both independently and collaboratively and apply professional knowledge to ensure that assignments are completed efficiently and on time.
  • Must possess mathematical skill and ability to understand complex data, terminology, procedures, laws, and regulations.
  • Ability to interpret and apply codes and standards within the discipline in which they are hired.
  • Nuclear Facility Worker - This position is subject to the requirements of DOE Order 426.2. Education and experience requirements will be screened accordingly.
  • The primary work location will be at the Nevada National Security Site (located 65 miles northwest of Las Vegas, Nevada).
  • Work schedule for this position will be 4/10’s, Monday – Thursday (subject to change).
  • Pre-placement physical examination, which includes a drug screen, is required. MSTS maintains a substance abuse policy that includes random drug testing.
  • Must possess a valid driver’s license.

MSTS is required by DOE directive to conduct a pre-employment drug test and background review that includes checks of personal references, credit, law enforcement records, and employment/education verifications. Applicants offered employment with MSTS are also subject to a federal background investigation to meet the requirements for access to classified information or matter if the duties of the position require a DOE security clearance. Substance abuse or illegal drug use, falsification of information, criminal activity, serious misconduct or other indicators of untrustworthiness can cause a clearance to be denied or terminated by DOE, resulting in the inability to perform the duties assigned and subsequent termination of employment. In addition, Applicants for employment must be able to obtain and maintain a DOE Q-level security clearance, which requires U.S. citizenship, at least 18 years of age. Reference DOE Order 472.2, “Personnel Security”. If you hold more than one citizenship (i.e., of the U.S. and another country), your ability to obtain a security clearance may be impacted.


Department of Energy Q Clearance (position will be cleared to this level). Reviews and tests for the absence of any illegal drug as defined in 10 CFR Part 707.4, “Workplace Substance Abuse Programs at DOE Sites,” will be conducted.  Applicant selected will be subject to a Federal background investigation, required to participate in subsequent reinvestigations, and must meet the eligibility requirements for access to classified matter. Successful completion of a counterintelligence evaluation, which may include a counterintelligence-scope polygraph examination, may also be required. Reference 10 CFR Part 709, “Counterintelligence Evaluation Program.”


MSTS is an Equal Opportunity/Affirmative Action Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, veteran status or other characteristics protected by law. MSTS is a background screening, drug-free workplace.


Annual salary range for this position is $94,556.80 - $141,835.20.

Starting salary is determined based on the position market value, the individual candidate education and experience and internal equity. 


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