• Journal of environmental and Sanitary engineering
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• v.14 no.3
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• pp.116-122
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• 1999

The purpose of this study is to develop new process named "hydrogen peroxide dissolution method". This process used hydrogen peroxide, which is harmless to human body and oxidize molybdenum wire selectively.The advantages of hydrogen peroxide dissolution method were no discharge of noxious matter when dissolution of molybdenum wire which used as the center supporter, reactions occur in room temperature and easy to recover dissolved molybdenum. This study was aimed at gathering the basic data of molybdenum wire dissolution-recovery process and proposes the reaction condition of molybdenum wire dissolution-recovery process and the factors influencing those reactions. The results were as follows:1. In the dissolution of molybdenum wire, the early condition of reaction was $15^{\circ}C$, and the temperature condition of state was $32^{\circ}C$. 2. 1) In the GSL-60W type, P.W.(Piece weight) was 11.89mg, C.R. was $65.6\Omega$. 2) In the FL-20W type, P.W. was 11.60mg, C.R. was $4.6\Omega$. 3. The molybdenum of process water was treated of a precipitation after dry and after stagnation in the one day, the molybdenum of upper water was treated of precipitation after dry and after congelation.

• Journal of environmental and Sanitary engineering
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• v.14 no.2
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• pp.1-7
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• 1999

In the tungsten industry as light source material, tungsten filament which used as light source material ould form after molybdenum wire which used as the center supporter for coil shape tungsten wire was removed. The purpose of this study is to develop new process named "hydrogen peroxide dissolution method". This process uses hydrogen peroxide, which is harmless to human body and oxidize molybdenum wire selectively. The results were as follows:1. The dissolution of molybdenum wire was proportion to a solution and contact surface of molybdenum wire. 2. The optimum $H_2O_2/H_2O$ were 1:0.5 ~ 1:1.75. 3. The time of dissolution was 65~70 minutes, and the PCS of sample were 20,800 PCS(1,820g). 4. Total cost($H_2O_2$, catalyst) was ￦19,088.

• Journal of environmental and Sanitary engineering
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• v.18 no.2
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• pp.1-8
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• 2003

The advantages of hydrogen peroxide dissolution method were no discharge of noxious matter when dissolution of molybdenum wire which used as the center supporter, reactions occur in room temperature. The results were as follows : 1. In the FL/10-A type: Dissolution-reaction Time was 50Min., C.R.(Coil resistance) was $9.27{\Omega}(St.{\;}:{\;}9.2{\pm}0.22{\Omega})$, P.W.(Piece weight) was $10.59mg(St.{\;}:{\;}10.5{\pm}0.26mg)$. In the FL/15-D type: Dissolution-reaction Time was 55Min., C.R. was $6.39{\Omega}(St.{\;}:{\;}6.38{\pm}0.02{\Omega})$, P.W. was $16.7mg(St.{\;}:{\;}16.5{\pm}0.3mg)$. In the FL/20-H type: Dissolution-reaction Time was 45Min., C.R. was $4.7{\Omega}(St.{\;}:{\;}4.6{\pm}0.3{\Omega})$, P.W. was $20.8mg(St.{\;}:{\;}20{\pm}1.5mg)$. In the FL/20-C type: Dissolution-reaction Time was 60Min., C.R. was $4.5{\Omega}(St.{\;}:{\;}4.6{\pm}0.3{\Omega})$, P.W. was $19.8mg(St.{\;}:{\;}19{\pm}1.0mg)$. 2. In the GLS-230/40-B type: Dissolutiona-reaction Time was 45Min., C.R. was $105.1{\Omega}(St.{\;}:{\;}104{\pm}2.6{\Omega})$, P.W was $6.37mg(St.{\;}:{\;}6.3{\pm}0.16mg)$. In the GLS-230/60-F type: Dissolution- reaction Time was 45Min., C.R. was $65.92{\Omega}(St.{\;}:{\;}65{\pm}1.62{\Omega})$, P.W. was $11.91mg(St.{\;}:{\;}11.8{\pm}0.29mg)$.

• Journal of the Korean Electrochemical Society
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• v.2 no.3
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• pp.150-155
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• 1999

The Electrochemical stabilities of the Brewer-Engel type intermetallic compounds of Co-Mo $(35 wt\%)$ and Ni-Mo$(35 wt\%)$ manufactured by the arc-melting method for the hydrogen electrode of $H_2-O_2$ alkaline fuel cell were investigated. Effects of temperature and concentration on the electrochemical behavior of the electrodes in the $80^{\circ}C$ 6 N KOH solution deaerated with $N_2$ gas were studied by electrochemical methods. The effect of overpotential on the electrochemical stabilities of Co-Mo and Ni-Mo intermetallic compounds was also discussed under the normal operation condition of AFC. It was shown that Co-Mo electrode had lower electrochemical stability as compared to Ni-Mo. In the case of Co-Mo electrode, a simultaneous dissolution of cobalt and molybdenum has occurred at low anodic overpotential form equilibrium hydrogen electrode potential, but the dissolution of cobalt was serious, and Co(OH)l layer on the electrode surface formed at the high anodic overpotential. In contrast the Ni-Mo electrode had high electrochemical stability because formation of the dense and thin protective $Ni(OH)_2$ layer prevented the dissolution of molybdenum.

• Nuclear Engineering and Technology
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• v.45 no.7
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• pp.979-986
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• 2013

Uranium metal particle dispersion plates have been proposed as targets for Molybdenum-99 (Mo-99) production to improve the radioisotope production efficiency of conventional low enriched uranium targets. In this study, uranium powder was produced by centrifugal atomization, and miniature target plates containing uranium particles in an aluminum matrix with uranium densities up to 9 $g-U/cm^3$ were fabricated. Additional heat treatment was applied to convert the uranium particles into UAlx compounds by a chemical reaction of the uranium particles and aluminum matrix. Thus, these target plates can be treated with the same alkaline dissolution process that is used for conventional $UAl_x$ dispersion targets, while increasing the uranium density in the target plates.

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.34-41
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• 2024

This work presents experimental data and modelling of the release of Mo from high-burnup spent nuclear fuel (63 MWd/kgU) at two different pH values, 8.4 and 13.2 in air. The release of Mo from SF to the solution is around two orders of magnitude higher at pH = 13.2 than at pH = 8.4. The high Mo release at high pH would indicate that Mo would not be congruently released with uranium and would have an important contribution to the Instant Release Fraction, with a value of 5.3%. Parallel experiments with pure non irradiated Mo(s) and XPS determinations indicated that the faster dissolution at pH = 13.2 could be the consequence of the higher releases from metallic Mo in the fuel through a surface complexation mechanism promoted by the OH^- and the oxidation of the metal to Mo(VI) via the formation of intermediate Mo(IV) and Mo(V) species.

• Journal of environmental and Sanitary engineering
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• v.15 no.2
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• pp.34-40
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• 2000

In the tungsten industry, molybdenum wire which used as the center supporter for coil shape tungsten wire was removed. Nitric acid dissolution method which used prevalently up to the present, takes nitric acid as major component and use noxious material such as sulfuric acid and hydrochloric acid remove molybdenum wire which used as center supporter by dissolve selectively within the range of no damage on tungsten wire. Mixed acid waste water occurred to the process were difficult to be decomposed by the conventional methords. This mixed acid waste water was treated by ozone, and It was obtained using possible by-product through the treatment waste water. For the three reactors with the same volume ; Blank reactor, Disturbance plate reactor, Packed-bed reactor ; the results were as follows : For the blank reactor COD removal efficiency in the pH = 4 (HRT : 6hr) was 28.5%, COD removal efficiency in the pH = 7 (HRT : 6hr) was 28.6%, and COD removal efficiency in the pH = 10 (HRT : 6hr) was 27.8%. For the disturbance plate reactor COD removal efficiency in the pH = 4 (HRT : 6Min.) was 86.5%, COD removal efficiency in the pH =7 (HRT : 6Min.) was 84.4%, and COD removal efficiency in the pH = 10 (HRT : 60Min.) was 86.8%. For the packed-bed reactor COD removal efficiency in the pH = 4 (HRT : 40Min.) was 76.0%, COD removal efficiency in the pH = 7 (HRT : 40Min.) was 81.3%, and COD removal efficiency in the pH = 10 (HRT : 40Min.) was 84.6%. After O3 treatment using possible by-product(Na2SO4) was 150g/ℓ.

• Corrosion Science and Technology
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• v.22 no.6
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• pp.478-483
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• 2023

This study examined the corrosion behavior of bimetal materials composed of Fe-Ni alloy and Fe-Ni-Mo alloy, both suitable for use in electromagnetic switches. Electrochemical polarization and weight loss measurements revealed that, in contrast to Fe-Ni alloy, which exhibited pseudo-passivity behavior, Fe-Ni-Mo alloy had higher anodic current density, displaying only active dissolution and greater weight loss. This indicated a lower corrosion resistance in the Fe-Ni-Mo alloy. Equilibrium calculations for the phase fraction of precipitates suggested that the addition of 1 wt% Mo may lead to the formation of second-phase precipitates, such as Laves and M₆C, in the γ matrix. These precipitates might degrade the homogeneity of the passive film formed on the surface, leading to localized attacks during the corrosion process. Therefore, considering the differences in corrosion kinetics between these bimetal materials, the early degradation caused by galvanic corrosion should be prevented by designing a new alloy, optimizing heat treatment, or implementing periodic in-service maintenance.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.143-149
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• 1999

In the tungsten industry as light source material, tungsten filament which used as light source material could form after molybdenumwire which used as the center supporter for coil shape tungsten wire was removed. This process uses hydrogen peroxide, Ozone and UV(Ultraviolet)Lamp, for the quantity of hydrogen peroxide decrease. The results were as follows : 1. An incandescent electric Lamp type : FL(FL-20) type : A standard of commodity (P.W.: $19{\pm}1.0mg$, $C.R:4.5{\pm}0.3{\Omega}$) 1) Only hydrogen peroxide treated ; Reaction Time : 65Min., P.W.: 18.60mg, $C.R.:4.60{\Omega}$ 2) Ozone/Ultraviolet/70% of hydrogen peroxide; Reaction Time : 64Min., P.W.: 18.61mg, C.R.: $4.61{\Omega}$ 2. A Fluorescent Lamp Type : GLS(GLS-40) Type : A standard of commodity(P.W.: $11.8{\pm}0.2mg$$65{\pm}1.5{\Omega}$) 1) Only hydrogen peroxide treated ; Reaction Time: 72Min, P.W.:11.88mg, C.R.: $65.62\Omega$ 2) Ozone/Ultraviolet/70% of hydrogen peroxide;Reaction Time:71Min., P.W.:11.88mg, C.R.: $65.63\Omega$

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1517-1523
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• 2020

The widely used medical isotope technetium-99 m (^99mTc) is a daughter of Molybdenum-99 (⁹⁹Mo), which is mainly produced using dedicated research reactors from the nuclear fission of uranium-235 (²³⁵U). ^99mTc has been used for several decades, which covers about 80% of the all the nuclear diagnostics procedures. Recently, the instability of the supply has become an important topic throughout the international radioisotope communities. The aging of major ⁹⁹Mo production reactors has also caused frequent shutdowns. It has triggered movements to establish new research reactors for ⁹⁹Mo production, as well as the development of various ⁹⁹Mo production technologies. In this context, a new research reactor project was launched in 2012 in Korea. At the same time, the development of fission-based ⁹⁹Mo production process was initiated by Korea Atomic Energy Research Institute (KAERI) in 2012 in order to be implemented by the new research reactor. The KAERI process is based on the caustic dissolution of plate-type LEU (low enriched uranium) dispersion targets, followed by the separation and purification using a series of columns. The development of proper waste treatment technologies for the gaseous, liquid, and solid radioactive wastes also took place. The first stage of this process development was completed in 2018. In this paper, the results of the hot test production of fission ⁹⁹Mo using HANARO, KAERI's 30 MW research reactor, was described.