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Areas of Activities
Top Products
Products & Services
INSPECTION OF REACTOR PRESSURE VESSEL HEAD
INETEC is performing inspections of PWR and VVER Reactor Pressure Vessel Heads using its own state-of-the-art sophisticated equipment
Reactor Pressure Vessel Head Inspection overview
- INETEC acquired hands-on experience in:
• Loviisa NPP (1996, VVER)
• Krako NPP (2001 and 2003, PWR Westinghouse) - Approach differs for VVER and PWR type reactors
- Inspection of RPVH penetrations are extremely difficult tasks which require the latest developments in manipulator manufacturing, ultrasonic inspection techniques, eddy current inspection techniques as well as video technique
- The most demanding components for inspection of RPVH penetrations are:
• special inspection manipulators
• custom design probes
• special software for ultrasonic (UT) and eddy current (EC) data analysis suited to the particular probe design - INETEC Inspection System for Reactor Pressure Vessel Head
PWR RPVH inspections
RPVH Manipulator provides accurate positioning of End Effectors:
• Stand with legs
• Arm & pole
• Vertical Carriage
• Remote Docking System (Capability for Maintenance Outside of the Head)
- Tool End Effectors (EC and UT)
- Pneumatic System
- ECT System
- Video System
- UT System
- Water supply system (UT coupling)
NRC document 7590-01-P defines the scope of inspection for the RPV head on a PWR type plant
The basic qualification requirement for inspections is the ability to detect defects whose size is equal or greater than:
• Width 0.25 mm (0.01”)
• Depth 0.5 mm (0.02”)
• All orientations
(ASME Section XI, Division 1, Appendix IV, Supplement 2, “Qualification Requirements for Surface Examination of Piping and Vessels”)
VHP Nozzle Weld Examination
- EC & UT End Effectors for inspection of VPH nozzle with and without Thermal Sleeve
- EC & UT sword Probe for Gap Inspection:
• Capability of entering the gap ? 3 mm
• Scan speed up to 100 mm/s
Probe carrier provides:
• Centering of the End Effector on Penetration
• Driving the Probe in and out of the gap
• Rotating (Indexing) the probe around the penetration axis - EC technique is used for detection of PWSCC – it has the advantage of sensitivity to small flaws:
• detection of ID surface and subsurface circumferential flaws (LxWxD=10x0.25x0.3 mm)
• detection of ID surface and subsurface axial flaws
• (LxWxD=10x0.25x0.2 mm)
• detection of subsurface flaws at depths up to 1.5 mm
- UT is used for sizing of flaws larger than 2 mm in depth dimension (TOFD Technique - angle beam).
- Both methods used in conjunction present an efficient detection and sizing tool.
CRDM J Groove Weld Examination
- Particular probes are used for specific parts
- Array probe:
• 16 Coils
• Differential Mode
• Driver Pickup Mode
• Scanning time for one half-way is about 5 seconds - Plus Point pen probe: 2 pieces = coverage up to 17 mm of Alloy 600 nozzle
VVER RPVH inspections
- 5 different End Effectors and examination techniques have been developed in order to cover the required scope of examinations:
• Volumetric examination of PT to head weld and adjacent base material (UT End Effector)
• Surface examination of the PT to head weld and adjacent clad material (EC End Effector)
• Examination of the inner surface of the corrosion protecting tubes (EC gap End Effector).
• The Visual Testing of the RVH interior and circumferential PT weld (VT End Effector #1)
• The visual testing of the heat protecting tube (VT End Effector #2) - Manipulator features:
• Remote docking
• Substituting End Effectors
• Service out of the high radiation area
EC Testing
- Gap scan and weld surface EC Testing End Effectors have been developed:
• to provide satisfactory contact of coils to the examination surface
• to detect and size artificial flaws (EDM notches and bore holes) emanated from Corrosion Protecting Tube ID surface and weld surface - Minimal flaw sizes applied:
• bore hole (0.07” dia x 0.118” dp. From I.D.)
• I.D. axial notch (WxDxL=0.008”x0.04”x0.4”)
• I.D. circ notch (WxDxL= 0.008”x0.08”x0.4”)
UT Examination
Ultrasonic Testing technique have been developed:
• to provide constant contact between the probes and examination surface
• to provide sufficient coupling to transfer ultrasonic energy, but not to spread the water on the area beneath RPVH
• to detect and size artificial flaws
Visual Testing
Visual examinations are performed on three areas of interest:
• Interior of inner stainless steel heat protection tubes by REES radial viewing head and R93 MK3 camera
• PT circumferential welds
• RVH interior by REES R93 MK3 zoom camera
The system resolution has been established on the basis of 1/32 inch black line on the 18% gray card
EddyOne Analysis software
The module for analysis of INETEC RPV Head probe data was developed to assure:
• User friendly approach
• Fully 3D data analysis
• Great speed of data calibration and data analysis
• Simultaneous balancing of all the channels at the same time
• Simultaneous rotating of all the channels at the same time
• 3D render view
• Color Top view
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