Riser Difference Uncertainty Methodology Based on Tank AY-101 Wall Thickness Measurements with Application to Tank AN-107

Weier, Dennis R. ; Anderson, Kevin K. ; Berman, Herbert S.

Pacific Northwest National Laboratory (U.S.)

关键词: Statistics;    Radioactive Waste Storage;    Tank Farm;    Walls;    Uncertainty;   

DOI  :  10.2172/15016054
RP-ID  :  PNNL-15182
RP-ID  :  AC05-76RL01830
RP-ID  :  15016054

美国|英语

来源: UNT Digital Library

【 摘 要 】

The DST Integrity Plan (RPP-7574, 2003, Double-Shell Tank Integrity Program Plan, Rev. 1A, CH2M HILL Hanford Group, Inc., Richland, Washington.) requires the ultrasonic wall thickness measurement of two vertical scans of the tank primary wall while using a single riser location. The resulting measurements are then used in extreme value methodology to predict the minimum wall thickness expected for the entire tank. The representativeness of using a single riser in this manner to draw conclusions about the entire circumference of a tank has been questioned. The only data available with which to address the representativeness question comes from Tank AY-101 since only for that tank have multiple risers been used for such inspection. The purpose of this report is to (1) further characterize AY-101 riser differences (relative to prior work); (2) propose a methodology for incorporating a ''riser difference'' uncertainty for subsequent tanks for which only a single riser is used, and (3) specifically apply the methodology to measurements made from a single riser in Tank AN-107.