DEGRADATION EVALUATION OF HEAVY WATER DRUMS AND TANKS

Mickalonis, J. ; Vormelker, P.

Savannah River Site (S.C.)

关键词: Storage;    Chlorides;    Specifications;    36 Materials Science;    Tanks;   

DOI  :  10.2172/1014150
RP-ID  :  SRNL-TR-2009-00195
RP-ID  :  DE-AC09-08SR22470
RP-ID  :  1014150

美国|英语

来源: UNT Digital Library

【 摘 要 】

Heavy water with varying chemistries is currently being stored in over 6700 drums in L- and K-areas and in seven tanks in L-, K-, and C-areas. A detailed evaluation of the potential degradation of the drums and tanks, specific to their design and service conditions, has been performed to support the demonstration of their integrity throughout the desired storage period. The 55-gallon drums are of several designs with Type 304 stainless steel as the material of construction. The tanks have capacities ranging from 8000 to 45600 gallons and are made of Type 304 stainless steel. The drums and tanks were designed and fabricated to national regulations, codes and standards per procurement specifications for the Savannah River Site. The drums have had approximately 25 leakage failures over their 50+ years of use with the last drum failure occurring in 2003. The tanks have experienced no leaks to date. The failures in the drums have occurred principally near the bottom weld, which attaches the bottom to the drum sidewall. Failures have occurred by pitting, crevice and stress corrosion cracking and are attributable, in part, to the presence of chloride ions in the heavy water. Probable degradation mechanisms for the continued storage of heavy water were evaluated that could lead to future failures in the drum or tanks. This evaluation will be used to support establishment of an inspection plan which will include susceptible locations, methods, and frequencies for the drums and tanks to avoid future leakage failures.