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Title: Application of CdZnTe Gamma-Ray Detector for Imaging Corrosion under Insulation

Abstract

Corrosion under insulation (CUI) on the external wall of steel pipes is a common problem in many types of industrial plants. This is mainly due to the presence of moisture or water in the insulation materials. This type of corrosion can cause failures in areas that are not normally of a primary concern to an inspection program. The failures are often the result of localised corrosion and not general wasting over a large area. These failures can tee catastrophic in nature or at least have an adverse economic effect in terms of downtime and repairs. There are a number of techniques used today for CUI investigations. The main ones are profile radiography, pulse eddy current, ultrasonic spot readings and insulation removal. A new system now available is portable Pipe-CUI-Profiler. The nucleonic system is based on dual-beam gamma-ray absorption technique using Cadmium Zinc Telluride (CdZnTe) semiconductor detectors. The Pipe-CUI-Profiler is designed to inspect pipes of internal diameter 50, 65, 80, 90, 100, 125 and 150 mm. Pipeline of these sizes with aluminium or thin steel sheathing, containing fibreglass or calcium silicate insulation to thickness of 25, 40 and 50 mm can be inspected. The system has proven to be a safe,more » fast and effective method of inspecting pipe in industrial plant operations. This paper describes the application of gamma-ray techniques and CdZnTe semiconductor detectors in the development of Pipe-CUI-Profiler for non-destructive imaging of corrosion under insulation of steel pipes. Some results of actual pipe testing in large-scale industrial plant will be presented.« less

Authors:
;  [1]
  1. Plant Assessment Technology (PAT) Group, Industrial Technology Division, Malaysia Institute for Nuclear Technology Research (MINT), Bangi, 43000 Kajang (Malaysia)
Publication Date:
OSTI Identifier:
21061709
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 909; Journal Issue: 1; Conference: ICSSST 2006: 2. international conference on solid state science and technology 2006, Kuala Terengganu (Malaysia), 4-6 Sep 2006; Other Information: DOI: 10.1063/1.2739828; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ABSORPTION; CADMIUM TELLURIDES; CALCIUM SILICATES; CORROSION; EDDY CURRENTS; GAMMA RADIATION; INSPECTION; MOISTURE; PIPELINES; SEMICONDUCTOR DETECTORS; SEMICONDUCTOR DEVICES; STEELS; ZINC TELLURIDES

Citation Formats

Abdullah, J., and Yahya, R. Application of CdZnTe Gamma-Ray Detector for Imaging Corrosion under Insulation. United States: N. p., 2007. Web. doi:10.1063/1.2739828.
Abdullah, J., & Yahya, R. Application of CdZnTe Gamma-Ray Detector for Imaging Corrosion under Insulation. United States. doi:10.1063/1.2739828.
Abdullah, J., and Yahya, R. 2007. "Application of CdZnTe Gamma-Ray Detector for Imaging Corrosion under Insulation". United States. doi:10.1063/1.2739828.
@article{osti_21061709,
title = {Application of CdZnTe Gamma-Ray Detector for Imaging Corrosion under Insulation},
author = {Abdullah, J. and Yahya, R.},
abstractNote = {Corrosion under insulation (CUI) on the external wall of steel pipes is a common problem in many types of industrial plants. This is mainly due to the presence of moisture or water in the insulation materials. This type of corrosion can cause failures in areas that are not normally of a primary concern to an inspection program. The failures are often the result of localised corrosion and not general wasting over a large area. These failures can tee catastrophic in nature or at least have an adverse economic effect in terms of downtime and repairs. There are a number of techniques used today for CUI investigations. The main ones are profile radiography, pulse eddy current, ultrasonic spot readings and insulation removal. A new system now available is portable Pipe-CUI-Profiler. The nucleonic system is based on dual-beam gamma-ray absorption technique using Cadmium Zinc Telluride (CdZnTe) semiconductor detectors. The Pipe-CUI-Profiler is designed to inspect pipes of internal diameter 50, 65, 80, 90, 100, 125 and 150 mm. Pipeline of these sizes with aluminium or thin steel sheathing, containing fibreglass or calcium silicate insulation to thickness of 25, 40 and 50 mm can be inspected. The system has proven to be a safe, fast and effective method of inspecting pipe in industrial plant operations. This paper describes the application of gamma-ray techniques and CdZnTe semiconductor detectors in the development of Pipe-CUI-Profiler for non-destructive imaging of corrosion under insulation of steel pipes. Some results of actual pipe testing in large-scale industrial plant will be presented.},
doi = {10.1063/1.2739828},
journal = {AIP Conference Proceedings},
number = 1,
volume = 909,
place = {United States},
year = 2007,
month = 5
}
  • The recent development of CdZnTe detectors has made it possible to produce CdZnTe based clinical radionuclide imagers. The authors therefore investigate the pixellation geometry ideal for this application using numerical simulation. These studies indicate that, for a fixed pixel pitch, configuring the detector with wide pixel and small interpixel spacing will optimize energy resolution and photopeak efficiency. Other issues concerning the practicality of medical imagers using CdZnTe are also discussed.
  • We are currently developing a handheld radioisotope identifier containing 18 position-sensitive CdZnTe crystals. In addition to isotope identification, the device performs basic Compton imaging to determine the location of suspected sources. This paper presents two computationally efficient algorithms for this purpose. The first algorithm traces individual Compton cones onto the unit sphere, whereas the second algorithm computes the intersection of two Compton cones and the unit sphere. Simulations demonstrate that the algorithms are suitable for determining the directionality, even with features such as uncertainty calculations omitted. The one-cone algorithm works more efficiently at high count rates, but the two-cone algorithmmore » generates fewer image artifacts.« less
  • The poor adhesion of common metals to CdZnTe (CZT)/CdTe surfaces has been a long-standing challenge for radiation detector applications. In this present work, we explored the use of an alternative electrode, viz., Al-doped ZnO (AZO) as a replacement to common metallic contacts. ZnO offers several advantages over the latter, such as having a higher hardness, a close match of the coefficients of thermal expansion for CZT and ZnO, and better adhesion to the surface of CZT due to the contact layer being an oxide. The AZO/CZT contact was investigated via high spatial-resolution X-ray response mapping for a planar detector atmore » the micron level. The durability of the device was investigated by acquiring I–V measurements over an 18-month period, and good long-term stability was observed. We have demonstrated that the AZO/CZT/AZO virtual-Frisch-grid device performs fairly well, with comparable or better characteristics than that for the same detector fabricated with gold contacts.« less