• Journal of Radiation Protection and Research
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• v.22 no.2
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• pp.77-83
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• 1997

Epoxy resin-type neutron shielding materials, KNS(Kaeri Neutron Shield)-101, KNS-102, and KNS-103 have been fabricated to be used in spent fuel shipping cask. The base material is epoxy resin, and polypropylene, aluminium hydroxide, and boron carbide are added. These shielding materials offer good fluidity at processing, which makes it possible to apply this resin shield to complicated geometric shapes such as shipping cask. The shielding property of these shielding materials for shipping cask for loading 28 PWR spent fuel assemblies has been evaluated. ANISN code is used to evaluate the shielding property of the shipping cask with the thickness of the three neutron shielding materials greater than 10 cm. As a result of analysis, the maximum calculated dose rate at the radial surface of the cask is determined to be $300{\mu}Sv/h$ and the maximum calculated dose rate at 100 cm from the cask is $97{\mu}Sv/h$. These dose rates remain within allowable values specified in related regulations.

• Applied Chemistry for Engineering
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• v.9 no.6
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• pp.884-888
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• 1998

Effects of heating time under high temperature on the thermal and mechanical properties of neutron shielding materials based on modified (KNS-102), hydrogenated(KNS-106) bisphenol-A type epoxy resin and phenol-novolac(KNS-611) type epoxy resin for radioactive material shipping casks have been investigated. At early stages, the initial decomposition temperatures of the shielding materials of KNS-102, KNS-106 and KNS-611 increased with the heating time under high temperature, but it was rarely affected by the heating time in the later stages. In addition, the thermal conductivities of KNS-102 and KNS-106 decreased with heating time, but that of KNS-611 increased with the heating time. On the contrary, the thermal expansion coefficients of neutron shielding materials decreased with increase of heating time. At the high temperature, the tensile strength and flexural strength of the shielding materials of KNS-102 and KNS-611 increased with heating time, but those of KNS-106 decreased with increase of heating time. And the heating time under high temperature on the neutron shielding materials did not show measurable loss of weight and hydrogen content.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.524-532
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• 1997

ffects of radiation on the thermal and mechanical properties of modified epoxy resin and hydrogenated bisphenol-A type epoxy resin based neutron shielding materials to be used for radioactive material shipping and storage casks have been investigated. The onset temperatures of the shielding materials of KNS(Kaeri Neutron Shield)-201 and KNS-302 increased with the radiation dose, but those of KNS-202 and KNS-301 decreased at radiation dose above 0.5 MGy. In addition, the radiation dose rarely affected the change of weight of shielding materials with the variation in temperature. At radiation dose up to 0.1 MGy, thermal conductivities of shielding materials were not affected. The thermal expansion coefficients of the shielding materials of KNS-301 and 302 were affected to a less extent than those of KNS-201 and 202 by radiation. At radiation dose up to 0.1 MGy, the tensile strength, compressive strength and flexural strength of the shielding materials of KNS-202 and KNS-301 and 302 increased with the radiation dose. In contrast, those of KNS-201 decreased with an increase in the radiation dose. In addition, the amount of radiation dose on the shielding materials did not result in a measurable loss of specific gravity, weight and hydrogen content.

• Korean Journal of Materials Research
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• v.8 no.5
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• pp.457-463
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• 1998

New neutron shielding materials, KNS-201, KNS-301 and KNS-601 have been fabricated to be used for radioactive material shipping and storage cask. The base materials are a modified and a hydrogenated bisphenol- A type and novolac type epoxy resin, and aluminium hydroxide and boron carbide are added. These shielding materials offer good fluidity at processing, which makes it possible to form this resin shield into complicated geometric shapes such as radioactive material shipping and storage cask. Several measurements were made for the shielding materials to evaluate the thermal and mechanical properties and radiation resistance. The properties of the shielding materials are as follows: onset temperatures 2S7~28$0^{\circ}C$, thermal conductivities 0.9S~1.14W/m. K, thermal expansion coefficients 0.77~1.26x$10_{-6}{\circ}C_{-1}$, combustion characteristics < 80$0^{\circ}C$, ATB(average time of burning) < 5sec, AEB(average extent of burning) < 5mm, tensile strengths 2.5~3.2kg/$\textrm{mm}^2$, compressive strengths 13.2~1S.2kg/$\textrm{mm}^2$, flexural strengths 5.2 -6.4kg/$\textrm{mm}^2$. In general, the concerned properties of KNS-201, KNS-301 and KNS-601 were revealed to be better than those of NS-4- FR. foreign neutron shielding material. It is also observed that the radiation resistance of KNS- 601 was better than those of KNS-201 and KNS-301.

• Applied Chemistry for Engineering
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• v.8 no.1
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• pp.92-98
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• 1997

Effects of radiation dose on mechanical properties such as tensile strength, compressive strength, flexural strength, specific gravity and changes of weight and hydrogen content of epoxy resin-type neutron shielding materials to be used for spent fuel shipping casks have been investigated. At radiation dose up to 0.5MGy, the tensile strength, compressive strength and flexural strength of the shielding materials of KNS-115A, KNS-115B and KNS-115C have been increased with increase in the radiation dose. In contract, these mechanical properties have been decreased at radiation dose above 0.5MGy. The amount of radiation dose on the materials of KNS-115A, KNS-115B and KNS-115C has not resulted in a measurable loss of specific gravity and weight of them, whereas the reduction of hydrogen content has been observed.

• Applied Chemistry for Engineering
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• v.7 no.3
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• pp.597-604
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• 1996

Resin-type neutron shielding materials, KNS-115A, 115B and 115C have been fabricated to be used for spent fuel shipping cask. The base material is epoxy resin, and polypropylene, aluminium hydroxide and boron carbide are added. These shielding materials offer good fluidity at processing, which makes it possible to apply this resin shield to complicated geometric shapes such as shipping cask. Several measurements were made for the shielding materials to evaluate the shielding property, combustion characteristics, fire resistance, thermal and mechanical properties. The neutron shielding ability of the shielding materials is estimated to be better than that of foreign's shielding material, NS-4-FR, due to higher hydrogen atomic density. Other properties of the shielding materials are as follows: Onset temperatures; $267{\sim}270^{\circ}C$, thermal conductivities; $0.62{\sim}0.72W/m{\cdot}K$, combustion characteristics; <$800^{\circ}C$, ATB(average time of burning); <5sec, AEB(average extent of burning) ; <5mm, tensile strengths; $2.3{\sim}3.0kg/mm^2$, compressive strengths; $5.3{\sim}13.3kg/mm^2$, flexural strengths; $4.4{\sim}5.4kg/mm^2$.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.3
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• pp.234-240
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• 2015

In the face of the world's growing energy storage needs, liquid hydrogen offers a high energy density solution for the storage and transport of energy throughout society. A 5 L liquid hydrogen storage tank has been designed, fabricated and tested to investigate boil-off rate of liquid hydrogen. As the insulation plays a key role on the cryogenic vessels, various insulation methods have been employed. To reduce heat conduction loss, the epoxy resin-based insulation supports G-10 were used. To minimize radiation heat loss, vapor cooled radiation shield, multi-layer insulation, and high vacuum were adopted. Mass flow meter was used to measure boil-off rate of the 5 L cryogenic vessel. A series of performance tests were done for liquid nitrogen and liquid hydrogen to compare with design parameters, resulting in the boil-off rate of 1.7%/day for liquid nitrogen and 16.8%/day for liquid hydrogen at maximum.