Detection and sizing of defects in control rod drive mechanism penetrations using eddy current and ultrasonics
Journal Article
·
· Journal of Pressure Vessel Technology
- Southwest Research Inst., San Antonio, TX (United States)
Over the last two years, concern has been generated about the capabilities of performing nondestructive evaluation (NDE) of the closure-head penetrations in nuclear-reactor pressure vessels. These penetrations are primarily for instrumentation and control rod drive mechanisms (CRDMs) and are usually thick-walled Inconel tubes, which are shrink-fitted into the steel closure head. The penetrations are then welded between the outside surface of the penetration and the inside surface of the closure head. Stress corrosion cracks initiating at the inner surface of the penetration have been reported at several plants. Through-wall cracks in the CRDM penetration or CRDM weld could lead to loss of coolant in the reactor vessel. The CRDM penetration presents a complex inspection geometry for conventional NDE techniques. A thermal sleeve, through which pass the mechanical linkages for operating the control rods, is inserted into the penetration in such a way that only a small annulus (nominally 3 mm) exists between the thermal sleeve and inside surface of the penetration. Ultrasonic (UT) and eddy current testing (ET) techniques that could be used to provide defect detection and sizing capability were investigated. This paper describes the ET and UT techniques, the probes developed, and the results obtained using these probes and techniques on CRDM penetration mock-ups.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 390213
- Journal Information:
- Journal of Pressure Vessel Technology, Journal Name: Journal of Pressure Vessel Technology Journal Issue: 3 Vol. 118; ISSN JPVTAS; ISSN 0094-9930
- Country of Publication:
- United States
- Language:
- English
Similar Records
Ultrasonic defect detection and size approximation using thin annulus probes
Nondestructive and Destructive Examination Studies on Removed-from-Service Control Rod Drive Mechanism Penetrations
NDE and DE of PWSCC Found in the J-Groove Weld of a Removed-From-Service Control Rod Drive Mechanism
Conference
·
Fri Dec 30 23:00:00 EST 1994
·
OSTI ID:72573
Nondestructive and Destructive Examination Studies on Removed-from-Service Control Rod Drive Mechanism Penetrations
Technical Report
·
Thu Jun 07 00:00:00 EDT 2007
·
OSTI ID:923690
NDE and DE of PWSCC Found in the J-Groove Weld of a Removed-From-Service Control Rod Drive Mechanism
Conference
·
Mon Dec 31 23:00:00 EST 2007
·
OSTI ID:962514