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Title: Underwater Laser Cutting Technology - 16491

Conference ·
OSTI ID:22838281
; ; ; ;  [1]
  1. IHI Corporation, 1 Shin-Nakahara-cho, Isogo-ku, Yokohama, Kanagawa (Japan)

Underwater dismantling is advantageous for the highly radioactive apparatuses such as nuclear reactor internals. The most advantageous point of underwater dismantling is a radiation exposure reduction for workers. Underwater dismantling can take advantage of the water shielding. Then it can make the exposure reduction for workers and contamination reduction for work area be realized. And, underwater laser cutting technology has major three advantages. First advantage is lower action force. Therefore it can be possible that we can use a simple remote device for underwater dismantling operation. Second advantage is to reduce secondary waste. The cutting kerf size of underwater laser cutting is very narrow, so the amount of cutting dross is very small. Third advantage is very simple methods for dismantling. This advantage can reduce process time for cutting. On the other hand, the contaminated off-gas which generates during cutting should be taken care. IHl Corporation (IHI) developed the underwater laser cutting devices. The characteristic of IHI's laser cutting torch is that there is no air habitat. Therefore, the positions of the torch and the access to the narrow space have little limitation. Using the device the series of performance tests were performed in order to verify the ability of it. In the first Laboratory test at 0.2 meter depth of water, we evaluated the optimum cutting parameters. The next underwater demonstration test at 6 meters depth of water was performed. In the test the cutting performance, which the mild steel plate of the thickness of 12 mm can be cut at the speed of 300 mm/min with the horizontal and downward position of torch was verified. Then the hot bubble test using real radioactive test coupons was performed to evaluate the radioactivity carried as air borne and the decontamination factor (DF) of off-gas passing through water. This document provides an overview of the underwater laser cutting device that has been developed by IHI, and the advantage of these devices for the dismantling work of underwater apparatus. (authors)

Research Organization:
WM Symposia, Inc., PO Box 27646, 85285-7646 Tempe, AZ (United States)
OSTI ID:
22838281
Report Number(s):
INIS-US-19-WM-16491; TRN: US19V1474083636
Resource Relation:
Conference: WM2016: 42. Annual Waste Management Symposium, Phoenix, AZ (United States), 6-10 Mar 2016; Other Information: Country of input: France; 2 refs.; available online at: http://archive.wmsym.org/2016/index.html
Country of Publication:
United States
Language:
English