Recent Projects

Nuclear Engineering Support for 324 Facility Decommissioning and Demolition (D&D) Activities Nuclear Safety and Technical Analysis

The 324 Building (Waste Technology Engineering Laboratory) is a Hazard Category 2 nuclear facility currently undergoing decommissioning and demolition.  During pre-demolition activities contaminated soil was discovered below the facility’s hot cell with dose rates exceeding  10,000 R/hour.  Polestar’s technical support included:

  • Using limited project data, personnel interviews, and facility drawings, Polestar personnel calculated radiological inventories within hot cells and areas throughout the facility and of discrete items
  • Used Monte Carlo N-Particle Transport Code (MCNP) to model radiological soil contamination below the B- Cell (~250,000 Ci of Cs-137/Sr-90)
  • Calculated radiological airborne emissions from point source emissions (existing exhaust stack) and fugitive emissions once the facility’s ventilation system was isolated and the facility was demolished
  • Performed technical evaluation of over 100 means and methods for determining D&D options for the 324 Facility demolition and extremely radioactive soil remediation below the facility
  • Performed Basis for Interim Operation (BIO) annual updates
  • Coauthored addendums to the BIO to support contamination stabilization/grouting activities and facility demolition
  • Performed nuclear criticality self-assessment for the 324 Facility project
  • Conducted Unreviewed Safety Questions (USQ) evaluations
  • Conducted hazard analysis meetings for proposed scope to support nuclear safety analyses
  • Developed nuclear safety step-out criteria for facility systems
  • Supported development and technical checking of the Emergency Planning Hazards Assessment (EPHA)


In summary, Polestar was able to (and continues to) provide highly competent individuals who are experienced and knowledgeable to assist the 324 Facility project with their challenging project.

Aerial photograph of 324 Facility Near the Banks of the Columbia River
Aerial photograph of 324 Facility Near the Banks of the Columbia River

Figure showing Modeled Contamination below Hot Cell