Abstract

Silver is generated in the reactor core during normal operation of very high temperature reactors (VHTRs). It may be transported as aerosols in the reactor circuit and plates out at different points in the reactor including the intermitted heat exchanger. The resuspension of particles in high temperature reactors is closely associated with source term analysis including the environment safety assessment. Adhesion force is important in determining resuspension rate used in resuspension calculations. In this work, the atomic force microscope was used to measure the adhesive force between a spherical silver particle and VHTRs structural materials of Hastelloy X and Inconel 617. These forces were also predicted through the Johnson-Kendall-Roberts (JKR) theoretical model. The theoretically calculated values (when the particle size of 15.1 μm diameter was used) are higher than the measured results by a factor of a 1000. However, when surface roughness was taken into account, an improved comparison between the theoretically predicted values and the measured values was observed. In fact, the comparisons between the theoretically predicted values and the measured results show a deviation that ranges from 0.155 to 0.422 in the case of Hastelloy X and from 0.243 to 0.503 in the case of Inconel 617. The data generated provide insight into the significant influence that surface roughness has on the adhesion force. This adhesion force data may be important in understanding the adhesion of silver particles to Hastelloy X and Inconel 617, and may contribute to particle resuspension calculations.

References

References
1.
Mokgalapa
,
N.
,
Ghosh
,
T. K.
, and
Loyalka
,
S. K.
,
2014
, “
Graphite Particle Adhesion to Hastelloy X: Measurements of the Adhesive Force With an Atomic Force Microscope
,”
Nucl. Technol.
,
186
(
1
), pp.
45
59
.
2.
Zhang
,
T.
,
Peng
,
W.
,
Shen
,
K.
, and
Yu
,
S.
,
2015
, “
AFM Measurements of Adhesive Forces Between Carbonaceous Particles and the Substrates
,”
Nucl. Eng. Des.
,
293
, pp.
87
96
.
3.
Mokgalapa
,
N.
,
Ghosh
,
T. K.
,
Tompson
,
R.
, and
Loyalka
,
S. K.
,
2016
, “
Adhesion Force Between a Silver Particle and Haynes 230: Role of Surface Conditions
,”
Nucl. Technol.
,
194
(
3
), pp. 353–368.
4.
Corwin
,
W. R.
,
2009
, “
Status of Ongoing Research Within the GIF VHTR Materials Project
,”
Gen-IV International Forum (GIF) Symposium
, Paris, France, Sept. 9–10, p.
113
.https://inis.iaea.org/search/search.aspx?orig_q=RN:43002312
5.
Lopez-Honorato
,
E.
,
Yang
,
D. X.
,
Tan
,
J.
,
Meadows
,
P. J.
, and
Xiaow
,
P.
,
2010
, “
Silver Diffusion in Coated Fuel Particles
,”
J. Am. Ceram. Soc.
,
93
, pp.
3076
3079
.
6.
Rowland
,
P. R.
,
1971
, “
Silver Release in the DRAGON Reactor
,” OECD Dragon Project, Technical Note DPTN/128.
7.
Nabielek
,
H.
, and
Brown
,
P. E.
,
1975
, “
The Release of Silver-110m in HTRs
,” DRAGON Project, Jahrestagung Kerntechnik, Nürnberg, Germany, Report No. DPTN/657.
8.
Merwe
,
H.
,
2004
, “
Development and Validation of Fission Product Release Models and Software at PBMR
,”
Second International Topical Meeting on High Temperature Reactor Technology (HTR-2004)
,
Beijing, China
,
Sept. 22–24
, Paper No. C18.
9.
Slabber
,
J.
,
2004
, “
Pebble Fuel Advantages
,”
Second International Topical Meeting on High Temperature Reactor Technology (HTR-2004)
,
Beijing, China
,
Sept. 22–24
, Paper No. B15.
10.
IAEA
,
1997
, “
Fuel Performance and Behavior in Gas Cooled Reactors
,” International Atomic Energy Agency, Vienna, Austria, Standard No. IAEA-TECDOC-978.
11.
Kugeler
,
K.
,
Stulgies
,
A.
, and
Epping
,
C.
,
1988
, “
Aerosol Formation During Water Ingress Into the Core of a Pebble Bed High-Temperature Reactor
,”
Aerosol Sci. Technol.
,
9
(
3
), pp.
177
187
.
12.
Neto
,
C.
, and
Craig
,
V. S. J.
,
2001
, “
Colloid Probe Characterization: Radius and Roughness Determination
,”
Langmuir
,
17
(
7
), pp.
2097
2099
.
13.
Sridharan
,
K.
,
Allen
,
T.
,
Anderson
,
M.
,
Cao
,
G.
, and
Kulcinski
,
G.
,
2011
, “
Final Report for Project: Emissivity of Candidate Materials for VHTR Applications: Role of Oxidation and Surface Modification Treatments
,” U.S. Department of Energy, Washington, DC, Report No.
DOE/ID/14820,1022709
.https://www.osti.gov/servlets/purl/1022709
14.
Maynard
,
R. K.
,
Ghosh
,
T. K.
,
Tompson
,
R. V.
,
Viswanath
,
D. S.
, and
Loyalka
,
S. K.
,
2010
, “
Total Hemispherical Emissivity of Potential Structural Materials for Very High Temperature Reactor Systems: Hastelloy X
,”
Nucl. Technol.
,
172
(1), pp. 88–100.
15.
Hao
,
H. W.
,
Bar
,
A. M.
, and
Senz
,
J. J.
,
1991
, “
Electrostatic and Contact Forces in Force Microscope
,”
J. Vac. Sci. Technol. B
,
9
(
2
), p.
1323
.
16.
Ducker
,
W. A.
,
Senden
,
T. J.
, and
Pashley
,
R. M.
,
1991
, “
Direct Measurement of Colloidal Forces Using an Atomic Force Microscope
,”
Nature
,
353
(
6341
), p.
239
.
17.
Abraham
,
D. W.
,
Williams
,
C. C.
, and
Wickramasignhe
,
H. K. J.
,
1988
, “
High-Resolution Force Microscopy of In-Plane Magnetization
,”
Microscopy
,
152
, p.
863
.
18.
Johnson
,
K. L.
,
Kendall
,
K.
, and
Roberts
,
A. D.
,
1971
, “
Surface Energy and the Contact of Elastic Solids
,”
Proc. R. Soc. Lond. A
,
324
(
1558
), pp.
301
313
.
19.
Rabinovich
,
Y. I.
,
Adler
,
J. J.
,
Ata
,
A.
,
Singh
,
R. K.
, and
Moudgil
,
B. M.
,
2000
, “
Adhesion Between Nanoscale Roughness Surfaces
,”
J. Colloidal Interface Sci.
,
232
(
1
), pp.
10
16
.
20.
Tabor
,
D.
,
1977
, “
Surface Forces and Surface Interactions
,”
J. Colloid Interface Sci.
,
58
(
1
), pp.
2
13
.
You do not currently have access to this content.