Safety analyses at the high flux isotope reactor (HFIR) are required to qualify experiment targets for the production of plutonium-238 (238Pu) from neptunium dioxide/aluminum cermet (NpO2/Al) pellets. High heat generation rates (HGRs) due to fissile material and low melting temperatures require a sophisticated set of steady-state thermal simulations in order to ensure sufficient safety margins. These simulations are achieved in a fully coupled thermo-mechanical analysis using comsolmultiphysics for four different preliminary target designs using an evolving set of pre- and postirradiation data inputs, and subsequently evolving solution scopes, from the unique pellet and target designs. A new comprehensive presentation of these preliminary analyses is given and revisited analyses of the first prototypical target designs are presented to reveal the effectiveness of evolving methods and input data.

Issue Section:
Research Papers
Keywords:
HFIR, multiphysics, heat transfer, structural mechanics, comsolmultiphysics
Topics:
Heat, Irradiation (Radiation exposure), Safety, Temperature, Manufacturing, Heat transfer, Design, Shrinkage (Materials), Geometry, Cycles, Thermomechanics

References

1.
Hurt
,
C. J.
,
Freels
,
J. D.
,
Hobbs
,
R. W.
,
Jain
,
P. K.
, and
Maldonado
,
G. M.
,
2016
, “
Thermal Safety Analyses for the Production of Plutonium-238 at the High Flux Isotope Reactor
,” Oak Ridge National Laboratory, Oak Ridge, TN, Report No. ORNL/TM-2016/234.
2.
Hurt
,
C. J.
,
Freels
,
J. D.
,
Griffin
,
F. P.
,
Chandler
,
D.
,
Hobbs
,
R. W.
, and
Wham
,
R. M.
,
2015
, “
Safety Analysis Models for the Irradiation of 237Np Targets at the High Flux Isotope Reactor
,”
Nuclear and Emerging Technologies for Space (NETS)
,
Albuquerque, NM
,
Feb. 23–26
, pp.
20
–
29
.
3.
Hurt
,
C. J.
,
Wham
,
R. M.
,
Hobbs
,
R. W.
,
Hobbs
,
R. W.
,
Owens
,
R. S.
,
Chandler
,
D.
,
Freels
,
J. D.
, and
Maldonado
,
G. M.
,
2014
, “
Plutonium-238 Production Target Design Studies
,”
Institute of Nuclear Materials Management 55th Annual Meeting
,
Atlanta, GA
,
July 20–24
, pp.
1111
–
1120
.
4.
Wham
,
R. M.
,
Felker
,
L. K.
,
Collins
,
E. D.
,
Benker
,
D. E.
,
Owens
,
R. S.
,
Hobbs
,
R. W.
,
Chandler
,
D.
, and
Vedder
,
R. J.
, 2014, “
The 238Pu Supply Project
,” The 19th Pacific Basin Nuclear Conference, Vancouver, BC, Aug. 24–28, pp. 643–651.
5.
Wham
,
R. M.
,
DePaoli
,
D. W.
, and
Hobbs
,
R. W.
,
2015
, “
Reestablishing the Supply of Plutonium-238
,” Transactions of the American Nuclear Society, Washington, DC, pp. 205–206.
6.
Oak Ridge National Laboratory
,
2014
, “
HFIR Updated Safety Analysis Report
,” Oak Ridge National Laboratory, Oak Ridge, TN, Report No. ORNL/HFIR/USAR/2344.
7.
Griffin
,
F. P.
,
2017
, “
RELAP5 Consolidated Model of High Flux Isotope Reactor System
,” Oak Ridge National Laboratory, Oak Ridge, TN, Report No. ORNL/RRD/INT-154.
8.
Chandler
,
D.
,
2015
, “
Neutronics Simulations of 237Np Targets to Support Safety-Basis and 238Pu Production Assessment Efforts at the High Flux Isotope Reactor
,”
Nuclear and Emerging Technologies for Space (NETS)
,
Albuquerque, NM
,
Feb. 23–26
, pp.
40
–
49
.
9.
Chandler
,
D.
,
2016
, “
Development of an Efficient Approach to Perform Neutronics Simulations for Plutonium-238 Production
,”
PHYSOR Conference
,
Sun Valley, ID
,
May 1–5
, pp.
913
–
927
.
10.
Incrupera
,
F. P.
, and
DeWitt
,
D. P.
,
2002
,
Fundamentals of Heat and Mass Transfer
, 6th ed.,
Wiley
,
Hoboken, NJ
.
11.
Griess
,
J. C.
,
Savage
,
H. C.
, and
English
,
J. L.
,
1961
, “
Effect of Heat Flux on the Corrosion of Aluminum by Water—Part III: Final 49 Report on Tests Relative to the High-Flux Isotope Reactor
,” Oak Ridge National Laboratory, Oak Ridge, TN, Report No. ORNL-3230.
12.
Madhusudana
,
C. V.
,
1995
,
Thermal Contact Conductance
,
Springer-Verlag
,
New York
.
13.
Ullman
,
A.
,
Acharya
,
R.
, and
Olander
,
D. R.
,
1974
, “
Thermal Accommodation Coefficients of Inert Gases on Stainless Steel and UO2
,”
J. Nucl. Mater.
,
51
(
2
), pp.
277
–
279
.
Google Scholar
Crossref
Search ADS
 
14.
Thomas
,
L. B.
, and
Loyalka
,
S. K.
,
1982
, “
Determination of Thermal Accommodation Coefficients of Inert Gases on a Surface of Vitreous UO2 at ∼35 °C
,”
Nucl. Technol.
,
59
(
1
), pp.
63
–
69
.
Google Scholar
Crossref
Search ADS
 
15.
Hall
,
R. O. A.
, and
Martin
,
D. G.
,
1987
, “
The Evaluation of Temperature Jump Distances and Thermal Accommodation Coefficients From Measurements of the Thermal Conductivity of UO2 Packed Sphere Beds
,”
Nucl. Eng. Des.
,
101
(
3
), pp.
249
–
258
.
Google Scholar
Crossref
Search ADS
 
16.
Rohsenow
,
W. M.
,
Hartnett
,
J. P.
, and
Ganic
,
E. N.
,
1985
,
Handbook of Heat Transfer Fundamentals
, 2nd ed.,
McGraw-Hill Book Co
,
New York
.
17.
Bondi
,
A.
,
1964
, “
Van Der Waals Volumes and Radii
,”
J. Phys. Chem.
,
68
(
3
), pp.
441
–
451
.
Google Scholar
Crossref
Search ADS
 
18.
Van Atta
,
C. M.
,
1965
,
Vacuum Science and Engineering
, 1st ed.,
McGraw-Hill
,
New York
, pp.
440
–
441
.
19.
Hirschfelder
,
J.
,
Curtiss
,
C.
, and
Bird
,
R.
,
1954
,
Molecular Theory of Gases and Liquids
, 1st ed.,
Wiley
,
New York
, p.
1110
.
20.
Brokaw
,
R. S.
,
1964
, “
Approximate Formulas for Viscosity and Thermal Conductivity for Gas Mixtures
,” National Aeronautics and Space Administration, Washington, DC, Report No. NASA TN D-2502.
21.
Saxena
,
S. C.
,
1957
, “
Thermal Conductivity of Binary and Ternary Mixtures of Helium, Argon, and Xenon
,” Indian J. Phys,
31
, pp.
597
–
606
.
22.
Jin
,
L.
,
Li
,
P.
,
Lei
,
X.
,
Zhou
,
H.
, and
Wang
,
C.
,
2014
, “
Mechanical and Thermal Properties of NpO2 Using LSDA+U Approach
,”
Prog. Nat. Sci. Mater. Int.
,
24
(
4
), pp.
373
–
377
.
Google Scholar
Crossref
Search ADS
 
23.
Sobolev
,
V.
,
2009
, “
Thermophysical Properties of NpO2, AmO2 and CmO2
,”
J. Nucl. Mat.
,
389
(
1
), pp.
45
–
51
.
Google Scholar
Crossref
Search ADS
 
24.
Howard
,
R. H.
,
Miller
,
J. H.
,
Owens
,
R. S.
,
Hemrick
,
J. G.
,
Erdman
,
D. L.
, III,
Schmidlin
,
J. E.
, and
Hawkins
,
C. S.
,
2014
, “
Mechanical and Thermal Properties for 237Np Pellets to Support 238Pu Production
,”
The Nuclear Materials Conference (NuMat2014)
,
Clearwater, FL
,
Oct. 27–30
.
25.
Hoffman
,
G. L.
,
Rest
,
J.
, and
Snelgrove
,
J. L.
,
1996
, “
Irradiation Behavior of Uranium Oxide—Aluminum Dispersion Fuel
,”
International Meeting for Reduced Enrichment for Research and Test Reactors
,
Seoul, Korea
,
Oct. 7–10
.
26.
Assmann
,
H.
, and
Stehle
,
H.
,
1978
, “
Thermal and in-Reactor Densification of UO2: Mechanisms and Experimental Results
,”
Nucl. Eng. Des.
,
48
(
1
), pp.
49
–
67
.
Google Scholar
Crossref
Search ADS
 
27.
Yanagisawa
,
K.
,
1986
, “
Fuel Densification and Swelling: Relationship Between Burn-Up Induced Axial and Radial Fuel Dimensional Changes
,”
Nucl. Eng. Des.
,
96
(
1
), pp.
11
–
20
.
Google Scholar
Crossref
Search ADS
 
28.
Meyer
,
R. O.
,
1976
, “
The Analysis of Fuel Densification—Aluminum Dispersion Fuel
,” Office of Nuclear Regulatory Commission, Washington, DC, Report No. NUREG-0085.
29.
Freels
,
J. D.
,
Jain
,
P. K.
, and
Hobbs
,
R. W.
,
2012
, “Design and
Nuclear-Safety Related Simulations of Bare-Pellet Test Irradiations for the Production of Pu-238 in the High Flux Isotope Reactor Using COMSOL
,”
COMSOL Conference
,
Boston, MA
,
Oct. 3–5
.
30.
Olander
,
D. R.
,
2009
, “
Nuclear Fuels: Present and Future
,”
Eng. J.
,
13
(
1
), pp.
1
–
28
.
Google Scholar
Crossref
Search ADS
 
31.
Hobbs
,
R. W.
,
Chandler
,
D.
,
Hurt
,
C. J.
,
Freels
,
J. D.
,
Owens
,
R. S.
, and
Bryan
,
C.
,
2015
, “
Potential Improvements to 238Pu Production Targets for the High Flux Isotope Reactor
,”
ANS Winter Meeting
,
Washington, DC
,
Nov. 8–12
, pp.
207
–
210
.
Copyright © 2019 by ASME
You do not currently have access to this content.