Mr. Mark Linn

Contact Details


From September 1989 to May 2021, served as reliability engineer and nuclear safety analyst in the Oak Ridge National Laboratory (ORNL) Research Reactors Division (RRD).  Responsibilities include:

  • Preparation of plant performance and reliability improvement programs, including preventive and predictive maintenance as well as condition monitoring of equipment.
  • Preparation of Maintenance Basis information and Preventive Maintenance Optimization processes.
  • Served as point of contact for RRD interfaces with external organizations and contractors (such as the Electric Power Research Institute) to identify and enable the use of relevant equipment performance improvement information within RRD.
  • Coordination of updates for the HFIR Probabilistic Risk Assessment and providing risk information support to the HFIR engineering and operations staff.
  • Coordination of the High Flux Isotope Reactor (HFIR) Updated Safety Analysis Report annual revisions.
  • Preparation of nuclear safety evaluations and unreviewed safety question determinations.
  • Identification, evaluation, and reporting of HFIR issues related to Price Anderson Amendment Act (PAAA).
  • Preparation of risk and reliability studies for the HFIR for operation, maintenance, and safety support, including preparation of Reliability Guides as support to RRD activities.
  • Providing probabilistic risk assessment expertise to other ORNL divisions as needed.
  • Participated in preparation of reports for Nuclear Regulatory Commission (NRC):
  • Developed a new method to evaluate risk and safety used by the NRC in the re-licensing of U.S. power reactors (NUREG-1437) using existing PRA results
  • Developed a new PRA-based method for the NRC review of the advanced design CANDU-3 (NUREG/CR-6065)
  • Participated in risk-vulnerability assessment of the Advanced CANDU Reactor ACR-700 designs using PRA methods
  • Participated in preparation of standards and reports for external organizations of American Nuclear Society (ANS), International Atomic Energy Committee (IAEA), and the Electric Power Research Institute.

From October 1986 to May 1989, served as supervisor of the BWR Units section of the Reliability and Performance Department for TVA.  Responsibilities included:

  • Reliability, risk analysis, and performance improvement for TVA Browns Ferry power plant including supervising a complete revision to the Browns Ferry Nuclear Plant probabilistic risk assessment and NRC Individual Plant Evaluation for BFNP.
  • Supervising other activities to support the Browns Ferry operations staff for restart of the plant, including a risk prioritized list of critical equipment for use in prioritizing maintenance, equipment qualification, and replacement parts activities.

 From February 1980 to September 1986, served as an engineer for the Reliability and Performance Section of the TVA Nuclear Engineering Branch.  Responsibilities included:

  • Preparation of reliability analyses for Bellefonte auxiliary feedwater, main feedwater, and process steam systems.
  • Coordinating the Bellefonte Severe Accident Sequence Analysis activities and coordinating preparation of the Bellefonte emergency procedure guidelines.
  • Serving as Secretary and Chairman of the Babcock & Wilcox Reactor Owner’s Group Operator Support Committee. In this position, oversaw multi-company teams that went to all B&W reactors to interview operations staff regarding management and technical nuclear safety concerns.  Managed the preparation of generic symptom-based operating procedures for all B&W reactors.
  • Lead engineer for the preparation of the Bellefonte probabilistic risk assessment.
  • Serving on NRC National Reliability Evaluation Peer Review Committee and NRC Accident Sequence Peer Review Committee.
  • Participation in IEEE Working Group 5.4 to develop PRA safety goal standard for nuclear power plants.
  • Performing as task manager for the NRC sponsored Interim Reliability Evaluation Program effort on the Browns Ferry plant.
  • Developing a program for the review of nuclear industry operating experience (Licensing Event Reports) by design personnel for the purpose of identifying operational and human factor lessons learned for feedback to TVA operating plants.

 From July 1975 to January 1980, served as engineer in the TVA Nuclear Licensing Section of the TVA Nuclear Engineering Branch.  Responsibilities included:

  • Responsibility for the technical evaluation of nonconformance reports including reportability to the NRC (10CFR50.55(e) and 10CFR21).
  • Assisting in preparation and coordination of responses to NRC questions on the Watts Bar and Bellefonte Safety Analysis Reports.
  • Assisting in preparation of the Yellow Creek Early Site Review Report and the Preliminary Safety Analysis Report.
  • Assisting in the preparation of responses to the NRC regarding the Browns Ferry Fire Recovery.