Robotic Reactor O-Ring Seal Inspection and Cleaning

  • Precise quantitative and qualitative analysis of reactor pressure vessel and head O-ring grooves and sealing surfaces
  • Laser measurements of sealing surface captured every 0.04” along the entire circumference of the closed seal
  • Greatly reduces dose exposure for outage personnel
  • Detection threshold at 90% POD – 0.002″
  • Measurements recorded to a database for comparing groove and surface degradation between outages
Innovative Inspection Technology

Diakont has developed a remote robotic system called the Aurora that conducts remote automated inspections of the reactor pressure vessel closure O-ring sealing surface between the reactor pressure vessel and the reactor vessel head.  The inspection system is comprised of two robots – one robot inspects the sealing surfaces on the reactor pressure vessel, and the other inspects those beneath the reactor vessel head. Diakont’s robotic system conducts comprehensive inspections using high-accuracy laser profilometry and high-definition visual inspection equipment. Checking for deformations, the system measures the linear dimensions of reactor vessel closure seal grooves and flange surfaces.

By utilizing the Aurora system instead of visual inspections, nuclear utilities are able to troubleshoot problematic reactor closure seals, improve their ALARA performance, and reduce personnel dose exposure by several hundred millirem. The high-accuracy readings from the Aurora system eliminate the risk of human error, which can lead to ineffective seals and pressure boundary leakages. The measurement data is stored, allowing for baseline comparisons of vessel and head flange conditions from outage to outage.



Inspection accuracy

+/- 0.001”

Reactor flange inspection time

~30 min

Total activity duration

~60 min

Travel speed

0.4” - 1.6”/sec

Sample points per circumferential slice


Circumferential sampling

Every 0.005”

Detection threshold (90% POD)


Absolute circumferential accuracy 


Tool envelope

26” х 15” х 4”

Total weight

36 lbs


Your Solutions Partner

Diakont’s expert team of project managers and nondestructive examination technicians will guide you through the entire reactor vessel closure seal inspection process, and meet or exceed your schedule requirements.



Robotic Reactor O-Ring Inspection Services