PMID- 31092955
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20201001
IS  - 0022-3115 (Print)
IS  - 1873-4820 (Electronic)
IS  - 0022-3115 (Linking)
VI  - 512
DP  - 2018
TI  - Natural alteration of (6)Li alumino-silicate glass.
LID - 10.1016/j.jnucmat.2018.09.034 [doi]
AB  - Understanding the chemical durability of neutron shielding materials is necessary 
      when assessing their long-term service potential. In this study, the chemical 
      durability of a (6)Li enriched neutron shielding glass that has been exposed to 
      natural, near-operational conditions is assessed by Prompt Gamma Activation 
      Analysis (PGAA) and Neutron Depth Profiling (NDP). These non-destructive, nuclear 
      analysis techniques are sensitive to (6)Li, and PGAA is uniquely able to detect H 
      in low quantities in solids. It was determined that the enriched alumino-silicate 
      glass can alter within 2 months of exposure to the natural environment. This 
      exposure resulted in an average surface alteration layer thickness of  approximately 22 mum. The 
      alteration layer contained  approximately 47% less (6)Li than the bulk glass. Alternatively, a 
      3 years exposed sample of the glass had a surface alteration depth of  approximately 30 mum and 
      (6)Li depletion levels in the alteration layer were between 47% and 75% less 
      (6)Li than the bulk glass. When the alteration layer on the 3 years sample was 
      removed, the H content of the glass's surface was nearly eliminated. This sample 
      also showed variable Li concentrations throughout the alteration volume, which 
      contrasts with near static Li concentration in the alteration volume of the 2 
      months sample. From these findings it was determined that the depletion in Li at 
      the surface of the glass will not affect the glass's neutron shielding 
      properties, but it may change the mechanical stability of the glass's surface 
      and, due to increased H content in the alteration layer, make it an inappropriate 
      material for the lining of certain neutron analysis instruments.
FAU - Weaver, Jamie L
AU  - Weaver JL
AD  - Material Measurement Laboratory, National Institute of Standards and Technology, 
      100 Bureau Drive, Gaithersburg, MD, 20899, USA.
FAU - Turkoglu, Danyal
AU  - Turkoglu D
AD  - NIST Center for Neutron Research, National Institute of Standards and Technology, 
      100 Bureau Drive, Gaithersburg, MD, 20899, USA.
LA  - eng
GR  - 9999-NIST/Intramural NIST DOC/United States
PT  - Journal Article
PL  - Netherlands
TA  - J Nucl Mater
JT  - Journal of nuclear materials. Journal des materiaux nucleaires
JID - 9882860
PMC - PMC6512992
MID - NIHMS1520848
EDAT- 2018/01/01 00:00
MHDA- 2018/01/01 00:01
PMCR- 2019/05/13
CRDT- 2019/05/17 06:00
PHST- 2019/05/17 06:00 [entrez]
PHST- 2018/01/01 00:00 [pubmed]
PHST- 2018/01/01 00:01 [medline]
PHST- 2019/05/13 00:00 [pmc-release]
AID - 10.1016/j.jnucmat.2018.09.034 [doi]
PST - ppublish
SO  - J Nucl Mater. 2018;512:10.1016/j.jnucmat.2018.09.034. doi: 
      10.1016/j.jnucmat.2018.09.034.