Home > Case Studies > Outage Activity Transport Monitoring - OATM

Outage Activity Transport Monitoring - OATM

Unparalleled expertise in radiation monitoring and data interpretation for CANDU power plants

OATM Survey Methodology

Kinectrics performs radiation surveys around reactor components during planned and forced outages at CANDU Power Plants to determine radionuclide distribution of deposits in the Primary Heat Transport System and to establish their trends.  

The surveys are based on both dose rate and gamma spectroscopy measurements.  They are performed to obtain a spatial distribution of the radiation field in the reactor vault at various elevations and distances from the reactor face. The data obtained from these surveys provides insight into the uniformity of deposits and helps to identify the locations of any hotspot(s).
Gamma spectral data are interpreted to estimate the absolute specific activity of individual radionuclides in the reactor components using previously established and validated models for:
  • Reactor Face (RF)
  • Reactor Vault
  • Vertical Feeder Cabinet
  • Horizontal Feeder Cabinet
  • Steam Generator
  • Moderator Heat Exchanger
  • Bleed Cooler and Condenser
Deconvolution of Radiation Field
Source location
Source type
   Distributed Deposit
   Localized Deposit
Radionuclide Composition
Specific Acitivity
Trend Analysis of Radiation Fields
To determine radiation field trends for a reactor unit, survey data collected during previous outages are compared in terms of absolute radionuclide activities.
Measured radiation fields and reactor component activities can exhibit various trends with time:  increasing, decreasing or mixed. Differences in these trends can possibly be rationalized based on a consideration of detailed operational data.
In particular Primary Heat Transport (PHT) coolant radiochemistry data, performance parameters of the PHT purification system and other operational parameters during reactor operation are all evaluated to establish their impact on the outage radiation fields.
Studies are currently underway to investigate correlations between radiation fields developed during normal and transient reactor operations and radiochemistry data of the coolant, as well as other operations parameters such as pH, bleed flow rates and purification system performance.