Security Control Assessor

Candidates must be a United States Citizen (no dual status) per contract requirements. Main Sail is seeking experienced Security Control Assessors to support cybersecurity and accreditation operations for a National Nuclear Security client located in Oak Ridge TN. Responsibilities: Implements and maintains security controls aligned with approved baselines and organizational requirements. Supports system authorization activities, including the development and maintenance of security documentation such as System Security Plans (SSPs) and Plans of Action and Milestones (POA&Ms). Monitors system security posture and identifies risks, vulnerabilities, and compliance gaps. Tracks and manages POA&Ms and coordinates remediation activities with system stakeholders. Assesses the security impact of system changes and supports configuration and change management processes. Supports continuous monitoring activities, including vulnerability management and security reporting. Serves as a security liaison between system teams, cybersecurity operations, and governance bodies. Prepares systems for security assessments, audits, and Authorizing Official reviews. Required Experience: Level 3: Bachelor's Degree w/ 2-5 yrs responsibilities experience; or Associates Degree w/ 5-10 yrs experience. Level 4: Master's Degree w/ 2-5 yrs responsibilities experience; or Bachelor's Degree w/ 5-10 yrs experience; or Associates Degree w/ 10-15 yrs experience. Level 5: Master's Degree w/ 5-10 yrs responsibilities experience; or Bachelor's Degree w/ 10-15 yrs experience; or Associates Degree w/ 15-20 yrs experience. Firm understanding of NIST SP 800-37 and NIST SP 800-53; CNSSI 1253 experience a plus. Requires current active DoE Q; or DoW TS. Location: Must reside within 50 miles of Y-12 Site, Oak Ridge TN. Period: 09/2026 - 09/2027 with possible extensions. #J-18808-Ljbffr