ML022460141
| ML022460141 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 08/29/2002 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| FOIA/PA-2002-0229 | |
| Download: ML022460141 (16) | |
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UT Inspection Approach for Davis Besse CRDM Nozzle Examinations ARAMATOME ANP
UT Inspection Approach for Davis Besse CRDM Nozzle Examinations Experience
- 7 Operating Plants
- 128 Nozzles Examined e 150 Cracks Detected and Characterized with UT ARAMATMMEANP
UT Inspection Approach for Davis Besse CRDM Nozzle Examinations Strategy
- Open Nozzles Use Rotating UT with Top-Down Tool Use blade UT from below on select nozzles to establish correlation with rotating probe
- Balance of Nozzles
- Use Blade UT from below with Circ. Probe e Detected flaws will be evaluated ARAMATOMEA__
UT Inspection Approach for Davis Besse CRDM Nozzle Examinations TOP-DOWN Examinations
- Available WhenDrive is Removed to Provide Access
- Uses Rotating UT probe
- 10 Transducers
- 0 deg., 5.0 MHz 30 deg L-wave, Axial TOFD, 5.0 MHz
- 45 deg. L-wave, Axial TOFD, 5.0 MHz
- 60 deg. S-wave, Axial - up/down, 2.25 MHz
- 45 deg. L-wave, Circ. TOFD, 5.0 MHz
- 55 deg. L-wave, Circ. TOFD, 5.0 MHz
- 65 deg. L-wave, Circ. TOFD, 5.0 MHz 60 deg. S-wave, Circ. - CW/CCW, 2.25 MHz Exam. Performed in two scans 1 for Axial Beams 1 for Circumferential Beams IFRAMATOME AN P
UT Inspection Approach for Davis Besse CRDM Nozzle Examinations Rotating UT Capabilities e Detection and Characterization of ID and hinNozzle Wall SDetection and Characterization of ID and Circumferential Cracks in Nozzle Wall
UT Inspection Approach for Davis Besse CRDM Ni Examinations 2ioRAMATOME ANP
UT Inspection Approach for Davis. Besse CRDM Nozzle Examinations
- Blade UT
- Used from beneath the head without removing drives Probe is inserted between lead screw support tube and CRDM nozzle gap -1/8"
- Two separate probes available
- Circumferential Probe (Axial Beam Direction)
- Used for Initial Examination
- Optimized for Circumferential Flaw Detection and Characterization
- Technique Has Good Capability for Axial Flaw Detection
- Has Good Capability to Identify Leak Path 1
- Axial Probe (Circumferential Beam Direction)
- Optimized for Axial Flaw Detection andCharacterization
- Used for Characterization of Axial Flaws YFRAMATOME ANP
UT Inspection Approach for Davis Besse CRDM Nozzle Examinations Axial Crack Detection Using Circ. Blade Probe
, Empirical Data Shows that Axial Flaws can be Detected With Beams Directed in the Axial Direction o Data exists for Rotating UT Probe with Axial TOFD Transducers 30 deg. and 45 deg., 5.0 MHz
"° Limited Data exists for Circ. Blade Probe 50 deg. 7.0 MHz used for demonstration 50 deg. 5.0 MHz now available
"° Coverage of Nozzle Wall is Similar for Rotating and Blade Probes for Axial Beam Direction ARA-MATO-ME ANP
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Detection of Axial Cracks With Axial Beam Direction IFRAMATOME ANP 17 83..
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UT Inspection Approach for Davis Besse CRDM Nozzle Examinations Axial Crack Detection Using Circ. Blade Probe Equivalency qan be established between Rotating and Circ.
Blade Probes based on:
- Similar coverage of the nozzle wall
- Same frequency of transducers (5.0 MHz)
- Similar responses from calibration block e Effectiveness will be verified by scanning selected nozzles using both probes AFRAMATOME.ANP
UT Inspection Approach for Davis Besse CRDM Nozzle Examinations Benefits of Using Circ. Blade Probe
"* Detects and Characterizes Circumferential Cracking
"* Detects Significant Axial Cracking
"* Detects Leak Path
- Minimizes Dose and Examination Time A'RAMATOME ANP