{"id":2831633,"url":"https://alion.io/job/atkinsrealis-senior-reactor-physicist-2","title":"Senior Reactor Physicist","company":{"id":8926,"name":"AtkinsRéalis","domain":"atkinsrealis.com","url":"https://alion.io/company/atkinsrealis","size_band":"5000+","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Workday","truth_index":{"grade":"B","score":84,"open_postings":436,"ghost_share":0.002,"stale_share":0.624,"repost_share":0.016,"time_to_fill_p50_days":41,"computed_at":"2026-10-30T05:48:23Z"}},"role":"Energy","role_family":"Energy","seniority":"senior","employment_type":"full_time","work_mode":"on_site","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["Mississauga, Canada"],"countries":["CA"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":73000,"max_usd":131000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":15},"experience_years_min":5,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"C++","optional":false},{"name":"Fortran","optional":false},{"name":"Linux","optional":false},{"name":"MCNP","optional":false}],"status":"live","first_seen_at":"2025-11-04T00:00:00Z","employer_posted_date":"2025-11-04","last_verified_at":"2026-10-30T00:18:10Z","board_verified":true,"closed_at":null,"days_open":360,"trust":{"level":"stale","repost_count":0,"flags":["stale"],"days_open":359},"description":"Job Description\nAre you looking for a company that works on major engineering projects all over the world? Do you want to make a difference by improving the daily lives of communities worldwide? Are you seeking to join an inclusive and diverse team that you can truly count on? You’ve come to the right place!\nCome join us in reshaping the future with AtkinsRéalis. AtkinsRéalis is dedicated in engineering a better future for our planet and its people.\nOur Reactor Core Physics Department at AtkinsRéalis/ Candu Energy is engaged in design and analysis work to support the design of new CANDU Nuclear Power Plants as well as supporting the operation and safety of the existing domestic and international CANDU plants. The Senior Reactor Physicist will work under specialist staff to assist in the development of advanced codes and methods and to perform technical analysis using up-to-date reactor physics codes, such as WIMS, DRAGON, RFSP and MCNP.\nLocation - Mississauga, ON\nYour role within the team:\nPerform and/or supervise the following calculations: Finite-reactor-core calculations, Kinetics calculations, Advanced-fuel-cycle calculations, Monte Carlo calculations.\n\nPrepare inputs, run reactor physics computer codes\n\nDevelop, adapt and modify FORTRAN computer codes as required for specific applications (e.g., to implement new methods or perform new types of calculations)\n\nDevelop methodologies and perform reactor physics analyses to support design and commercial activities and document analyses in technical notes and reports, present results at meetings\n\nEstimate, monitor schedules and assign work to meet completion dates Perform varied work assignments effectively and respond quickly to changing project needs\n\nPropose/develop approaches to be used on reactor physics tasks as well as develop analysis basis plans\n\nWhy choose AtkinsRéalis as an employer?\nBecause we offer:\nThe opportunity to work on various major projects for internal and external clients.\n\nAn exciting environment where work-life balance is important.\n\nA wide array of learning and development opportunities.\n\nCompetitive pay, flexible benefits, an employee share plan, and a defined contribution pension plan.\n\nA work environment focused on health and safety.\n\nThe ideal candidate:\nMasters degree or higher from a university of recognized standing in Physics or Nuclear Engineering or equivalent;\n\nExperience with CANDU reactor physics\n\nA minimum of 5 years of relevant experience (experience obtained in advanced degree programs will be considered for applicability against this requirement)\n\nExperience with reactor physics codes such as WIMS, DRAGON, RFSP , DONJON and/or MCNP\n\nExperience with nuclear data library creation\n\nExperience with few energy group constants and uncertainty assessment\n\nProficiency in both Linux and WINDOWS environments is a strong asset as well as computer programming, especially FORTRAN, C++ are very desirable Excellent oral and written communication skills are required\n\nAbility to work well under pressure and be flexible, i.e., must be able to perform varied work assignments effectively and respond quickly to changing project needs\n\nStrong problem solving skills are essential, ability to work to budget and schedule and a full commitment to working in a formal QA environment.\n\nWorker Type\nEmployeeJob Type\nRegularAt AtkinsRéalis, we seek to hire individuals with diverse characteristics, backgrounds and perspectives. 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