Mechanical Systems Engineer Leaf River, IL

• $92,700
• $114k Full Time Posted by: Constellation Energy

Posted:

Thursday, 30 July 2026 Who We Are As the largest private-sector power producer in the world and the nation's largest producer of clean and reliable energy, Constellation is focused on our purpose: lighting the way to a brilliant tomorrow for all. We have been the leader in clean energy production for more than a decade, and we are cultivating a workplace where our employees can grow, thrive, and contribute. Now integrated with Calpine, our portfolio includes 55 gigawatts of capacity from nuclear, natural gas, geothermal, hydro, wind and solar facilities, with the generating capacity to power the equivalent of 27 million homes. The Mechanical Systems Engineer position is based out of our Byron Clean Energy facility in Byron, IL. Our culture and employee experience make it clear: We are powered by passion and purpose. Together, we're creating healthier communities and a cleaner planet, and our people are the driving force behind our success. At Constellation, you can build a fulfilling career with opportunities to learn, grow and make an impact. By doing our best work and meeting new challenges, we can accomplish great things. Join us in meeting the country's energy needs today and tomorrow. Total Rewards Constellation offers an extensive selection of benefits and rewards to help our employees thrive professionally and personally. We provide competitive compensation and a wide-range of benefits that support both employees and their families, helping them prepare for the future. In addition to highly competitive salaries, eligible employees are offered a bonus program, 401(k) with company match, employee stock purchase program comprehensive medical, dental and vision benefits, including robust wellbeing programs disability and life insurance benefits paid time off for vacation, holidays, and sick days and much more. .This Engineering role can be filled at Mid-level or Senior Engineer level. Please see minimum qualifications list below for each level

• Mid Level
• $92,700
• 114,000 Sr Level
• $122,400
• 154,000 Ranges are per year based on experience, along with a comprehensive benefits package that includes bonus and 401K Primary Purpose of Position Responsible for performing engineering and technical tasks, under general supervision, in support of nuclear plant operations.

Primary Duties and Accountabilities Perform engineering and technical tasks as assigned by supervision applying general engineering principles Assure all engineering products prepared are in accordance with applicable safety analyses, industry codes, engineering specifications and all regulatory requirements. Participate in the development and implementation of effective processes and techniques at appropriate levels of detail and in compliance with established policies and procedures. Recommend format and methodology improvements to standard processes and procedures. Perform other job assignments and duties as directed by management or pursuant to company policy, including but not limited to emergency response, departmental coverage, call outs, and support of outage activities in positions outside the department.

MINIMUM QUALIFICATIONS

for Mid-level E02 Engineer B.S. in Engineering, a minimum 2 years Nuclear experience or related engineering experience Must meet additional requirements as outlined in

ANSI/ANS-3.1-2014

Standard, "Selection, Qualification, and Training of Personnel for Nuclear Power Plants" Maintain minimum access requirements or unescorted access requirements, as applicable, and favorable medical examination and/or testing in accordance with position duties

MINIMUM QUALIFICATIONS

for Senior E03 Engineer B.S. in Engineering, a minimum 5 years Nuclear experience or related engineering experience Must meet additional requirements as outlined in

ANSI/ANS-3.1-2014

Standard, "Selection, Qualification, and Training of Personnel for Nuclear Power Plants" Maintain minimum access requirements or unescorted access requirements, as applicable, and favorable medical examination and/or testing in accordance with position duties Preferred Qualifications BS Mechanical, Civil, Industrial or Chemical Engineering Engineer in Training Certification Good grasp of techniques and a good understanding of the fundamental functions performed by the group. As responsibility increases within the organization Experience with raw water systems Nuclear power plant experience Location Leaf River, IL, United States of America Industry IT Rate $92,700

• $114k Company Constellation Energy Contact Click apply Reference JS23502_17256_137257-AEFA7025BCFE229EA24AC03FC9035A56 Posted Date 7/30/2026 2:08:50 AM