Sr. Administrative Assistant - Weldon Spring, MO

RSI EnTech, LLC; Weldon Spring (MO); On-site; USD 30,000 - 39,000; Full time

Benefits offered by this job

PTO

Paid holidays

Medical insurance

Dental insurance

Vision insurance

401K match up to 4%

Life insurance

Disability insurance

Job summary

RSI EnTech, LLC seeks a Sr. Administrative Assistant in Weldon Spring, MO to provide critical project and program support to one or more technical managers.

The role involves routine administrative tasks, diary management, and coordinating with clients including LM, with less than 5% travel. The position requires a Bachelor’s degree or equivalent experience, +12 years in the field, and proficiency with Microsoft Office and SharePoint.

Qualifications

• Vocational/technical school diploma or bachelor’s degree; experience in lieu of education considered.
• Minimum of 12 years of job-related experience.
• Proficiency in Microsoft Office Suite (Word, Excel, Outlook, SharePoint, PowerPoint).
• Excellent customer service and communication skills.
• Analytical and team-building abilities.
• Highly organized with strong attention to detail.

Responsibilities

• Assist with developing, tracking, and submitting contract deliverables and other written work products for timely submittals per contract requirements.
• Provide general administrative support to the Site Lead as requested.
• Assist/track routine letters/emails.
• Interface with the client regularly.
• Prepare confidential correspondence, reports, and other documents.
• Take meeting notes for meetings including the Department of Energy LM client and technical managers as requested.
• Schedule LM client meetings and arrange tele-conference logistics.
• File records in Content Manager per processes.
• Manage documents and coordinate with Document Management.

Skills

Microsoft Office

Customer Service

Communication skills

Detail-oriented

Organizational skills

Education

Bachelor's degree

Experience in lieu of education

Tools

SharePoint

PowerPoint

Job description

About RSI

RSI is a dynamic group of companies that has provided services to major federal clients and Fortune 500 engineering and construction companies since 1996. We have experience in complex, highly regulated markets providing environmental, nuclear, construction management, project delivery, and specialty professional services while maintaining an excellent safety record.

We offer a full range of benefits including a generous PTO plan, paid holidays, medical, dental, vision, 401K (100% match up to 4% eligible compensation) and 100% immediate vesting, basic and supplemental life insurance, and short- and long-term disability.

RSI is headquartered in Oak Ridge, Tennessee, and is a wholly owned operating company of ASRC Industrial (AIS). AIS is a wholly owned operating company of Arctic Slope Regional Corporation (ASRC), an Alaska Native Corporation (ANC). Through ASRC, we are a certified Minority Business Enterprise (MBE) and Small Disadvantaged Business (SDB), and we also offer 8(a) options.

Position Summary

RSI is recruiting for a Sr. Administrative Assistant who will perform a variety of business‑related assignments in program and project management and provides administrative support for one or more technical managers performing specialized and routine administrative activities. May lead on more complex assignments and mentor’s junior staff.

Job Title:

Sr. Administrative Assistant

Location(s):

Weldon Spring, MO

Status:

Full-Time

FLSA:

Non-Exempt

Hiring Range:

$22.00 - 28.00 per hour. (The anticipated starting salary is based on the posted minimum requirements for this position. The offered salary will be based upon the selected applicant’s education, training, and experience.)

This position is required to travel less than 5% of the time.

Essential Duties and Responsibilities

• Assists with developing, tracking, and submitting contract deliverables and other written work products for timely submittals in accordance with contractual requirements.
• Provide general administrative support to the Site Lead as requested.
• Assist/track routine letters/emails.
• Interface with the client on a regular basis.
• Prepares confidential correspondence, reports, and other documents.
• Takes meeting notes for meetings including the Department of Energy’s Office of Legacy Management (LM) client and technical managers as requested.
• Schedules meetings with the LM client, arranging Tele-Conference meeting logistics.
• Files records in the authoritative database (i.e., Content Manager) per established processes.
• Manage documents and coordinate with Document Management.
• Assists with procedure development and revisions as requested.
• Manages calendars/emails as requested.
• Configures and manages SharePoint sites.
• Provide procurement support such as purchasing of technical equipment, supplies, materials, etc. as requested.
• Leads innovation and improvements within the group/groups they support.
• Serves as a site subject matter expert on administrative policies, procedures, and processes.
• Assists site personnel in navigating administrative requirements.
• Other duties as assigned.

Required Education and Years of Relevant Experience

• Vocational/technical school diploma or bachelor’s degree. Experience in lieu of education will be considered.
• Minimum of 12 years of job-related experience.

Licenses and Certifications

• Valid Driver’s License

Required Skills and Abilities

• Proficient in Microsoft Office Suite (Word, Excel, Outlook, SharePoint, PowerPoint)
• Excellent Customer Service
• Analytical and team‑building skills
• Demonstrated excellent written and verbal communication skills
• Excellent attention to detail
• Process oriented and highly organized; able to anticipate and facilitate next steps

Clearance and Health Requirements

• Criminal Background Check
• Pre-placement Drug Screening
• Fit for Duty Test (if applicable)

Essential Physical Requirements

Sedentary: Work involves exerting up to 10 pounds of force occasionally or a negligible amount of force frequently to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time but may involve walking or standing for brief periods of time. Jobs may be defined as sedentary when walking and standing are required only occasionally, and all other sedentary criteria are met.

Job Posting Close Date

September 28, 2026

EEO Statement

ASRC Industrial (AIS) and its operating companies affords equal opportunity in employment to all individuals regardless of race, color, religion, sex, age, national origin, pregnancy, familial status, disability status, veteran status, citizenship status, genetic information or any other characteristic protected under Federal, State or Local law. AIS is an Equal Opportunity Employer.

ASRC Industrial, ("AIS"), and its Operating Companies will never ask job candidates for sensitive personal information (such as Social Security numbers, banking details, or payment of any kind) during the hiring process. If you receive unsolicited communications from individuals claiming to represent ASRC Industrial using non-official email addresses (e.g., not from @asrcindustrial.com), please report the message and do not engage. Official job postings can always be found on our website: asrcindustrial.com/careers/ or https://rsienv.applicantstack.com/x/openings.