Acceptance criteria for ultrasonic flaw indications in the inner liner of double-shell waste storage tanks

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:418160

Simonen, F A ^[1]; Scott, K V; Pfluger, D C ^[2]

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1. Pacific Northwest National Lab., Richland, WA (United States)
2. Westinghouse Hanford Co., Richland, WA (United States)

Radioactive defense waste, resulting from the chemical processing of spent nuclear fuel, has been stored in double-shell tanks (DSTs) at the Hanford Site since 1970. As part of the program to assure that the DSTs maintain their structural integrity, an inspection plan is being developed and implemented. This paper describes the technical bases for acceptance criteria for flaw indications detected during ultrasonic inspection of inner liners of the DSTs. The types of indications addressed are crack-like flaws, wall thinning, and pitting. In establishing acceptable flaw sizes, the evaluations have taken into consideration the potential for crack growth by the mechanism of stress corrosion cracking. Critical flaw sizes have been based on elastic-plastic fracture mechanics with calculations being performed using the approach of the failure assessment diagram. The goal was to ensure that indications discovered during inspections are not large enough to ever cause a leak or rupture of the tank inner liner. The acceptance criteria were intended to be simple to apply using a set of tables giving acceptable flaw sizes. These tables are sufficiently conservative to be applicable to all double-shell tanks.

• DOE Contract Number: AC06-76RL01830
• OSTI ID: 418160
• Report Number(s): CONF-960706--; ISBN 0-7918-1769-5
• Country of Publication: United States
• Language: English

Related Subjects

05 NUCLEAR FUELS
CRACK PROPAGATION
CRACKS
DATA
HANFORD RESERVATION
RADIOACTIVE WASTE STORAGE
RADIOACTIVE WASTES
RELIABILITY
STORAGE FACILITIES
STRESS INTENSITY FACTORS
ULTRASONIC TESTING