Ultrasonic inspection techniques for two weld closures proposed for RSSF waste storage casks

Technical Report · Sun Jan 01 04:00:00 EST 1978

DOI:https://doi.org/10.2172/5129142· OSTI ID:5129142

Doctor, S R; Morris, C J

One method being considered for interim storage of high-level radioactive waste materials is to place these materials in large sealed stainless steel canisters and subsequently store these canisters in a second sealed steel storage cask. Weld procedures are proposed as the closure or seal for these vessels. Inspection of these closures to assure initial and long-term integrity of the closure welds presents a challenge to nondestructive testing. The environment is thermally (400 to 1000/sup 0/F) and radioactively (10/sup 5/ R/hr) hot necessitating remote inspection procedures. As a result of research work, ultrasonic test techniques were developed for inspecting the final weld closure of the waste cask. Special transducers, coupling techniques and fixturing were developed and demonstrated in a mockup test facility by remotely examining a 2-in. full penetration weld closure. The examination was performed at room ambient and at a temperature of 200/sup 0/F. Testing at the desired temperature of 400/sup 0/F was not completed due to a loss in transducer performance at temperatures in excess of 200/sup 0/F. Upon completion of the mockup test demonstration, the cask was subjected to a drop test. The ultrasonic results of the pre- and post-examination of two weld closures (the 2-in. full penetration weld and the threaded plug with seal weld) are presented. After the completion of the drop test, both weld closures were radiographed. The radiographs verified the ultrasonic examination and the presence of weld defects in the same areas. Sectioning of the cask closure welds with metallographic verification was not completed at the time of this writing. As a result of the experience gained from the Retrievable Surface Storage Facility (RSSF) storage cask program, recommendations pertaining to the nondestructive engineering development program for Spent Unreprocessed Fuel (SURF) storage casks are presented.

• Research Organization: Battelle Pacific Northwest Labs., Richland, Wash. (USA)
• DOE Contract Number: EY-76-C-06-1830
• OSTI ID: 5129142
• Report Number(s): PNL-2480
• Country of Publication: United States
• Language: English

Related Subjects

052002* -- Nuclear Fuels-- Waste Disposal & Storage
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
42 ENGINEERING
420500 -- Engineering-- Materials Testing
ACOUSTIC TESTING
CASKS
CONTAINERS
HIGH-LEVEL RADIOACTIVE WASTES
JOINTS
MANAGEMENT
MATERIALS TESTING
NONDESTRUCTIVE TESTING
RADIOACTIVE MATERIALS
RADIOACTIVE WASTE STORAGE
RADIOACTIVE WASTES
STORAGE
TESTING
ULTRASONIC TESTING
WASTE MANAGEMENT
WASTE STORAGE
WASTES
WELDED JOINTS