Neutron Radiation Embrittlement at 500 and 650 F of Reactor Pressurf Vessel Steels

2009 ◽  
pp. 116-116-21
Author(s):  
JV Alger ◽  
LM Skupien
Keyword(s):  
Neutron Radiation ◽  
Radiation Embrittlement

A Fracture-Toughness Based Transition Reference Temperature for Use in the ASME Code With the Crack Arrest (KIA) Curve

2014 ◽  
Author(s):  
Mark Kirk ◽  
Hieronymus Hein ◽  
Marjorie Erickson ◽  
William Server ◽  
Gary Stevens
Keyword(s):  
Fracture Toughness ◽  
Master Curve ◽  
Functional Form ◽  
Neutron Radiation ◽  
Crack Arrest ◽  
Reference Temperature ◽  
Radiation Embrittlement ◽  
Temperature Separation ◽  
Asme Code ◽  
Current Code

In the early 2000s, ASME adopted Code Cases N-629 and N-631 [1–2], both of which permit the use of the Master Curve reference temperature (To) to define an reference temperature RTTo, as follows (in SI units, as are used throughout the paper):RTTo=To+19.4℃The Code Cases state that “this reference temperature … may be used as an alternative to [the] indexing reference temperature RTNDTfor the KIcand KIatoughness curves, as applicable, in Appendix A and Appendix G [of Section XI of the ASME Code].” KIa is now only used in Appendix A. The functional form of the ASME KIc and KIa curves dictate that the temperature separation between them remains constant irrespective of the degree of neutron radiation embrittlement, as quantified by ΔRTNDT or ΔRTTo. However, data collected from the literature and new data reported by Hein et al. show that radiation embrittlement brings the KIc and KIa curves closer together as embrittlement increases. As a result, current Code guidance will not produce a bounding KIa curve in all situations when RTTo is used as an reference temperature. To reconcile this issue, this paper summarizes available data and, on that basis, concludes that use of the following reference temperature will ensure that the ASME KIa curve bounds currently available KIa data:RTKIa=RTTo-19.4+44.97×exp⁡−0.00613×RTTo-19.4

A new type of defect structure in 124-superconducting oxide revealed by HREM

1991 ◽  
Vol 49 ◽  
pp. 1092-1093
Author(s):  
R. Sharma ◽  
B.L. Ramakrishna ◽  
N.N. Thadhani ◽  
D. Hianes ◽  
Z. Iqbal
Keyword(s):  
Shock Wave ◽  
Defect Structure ◽  
Neutron Radiation ◽  
Weak Links ◽  
Defect Structures ◽  
New Materials ◽  
New Type ◽  
Current Densities ◽  
Processing Techniques ◽  
Microstructural Studies

After materials with superconducting temperatures higher than liquid nitrogen have been prepared, more emphasis has been on increasing the current densities (Jc) of high Tc superconductors than finding new materials with higher transition temperatures. Different processing techniques i.e thin films, shock wave processing, neutron radiation etc. have been applied in order to increase Jc. Microstructural studies of compounds thus prepared have shown either a decrease in gram boundaries that act as weak-links or increase in defect structure that act as flux-pinning centers. We have studied shock wave synthesized Tl-Ba-Cu-O and shock wave processed Y-123 superconductors with somewhat different properties compared to those prepared by solid-state reaction. Here we report the defect structures observed in the shock-processed Y-124 superconductors.

Observations of neutron radiation environment during Odyssey cruise to Mars

2021 ◽  
Vol 29 ◽  
pp. 53-62
Author(s):  
M.L. Litvak ◽  
I.G. Mitrofanov ◽  
A.B. Sanin ◽  
B. Bakhtin ◽  
D.V. Golovin ◽  
...  
Keyword(s):  
Neutron Radiation ◽  
Radiation Environment
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