• Proceedings of the Korean Nuclear Society Conference
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• 1998.05a
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• pp.609-614
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• 1998

고준위 방사성 폐기물 처분과 관련이 있는 가속기구동 소멸처리로는 미임계로이기 때문에 별도의 중성자원이 필요하다. 가속기에서 나오는 양성자를 받아 중성자를 발생시키는 중성자원으로 사용될 표적물로서 거론되는 방안중에 하나인 고체표적시스템에 대한 열전달 예비계산을 수행하였다. 고체표적물의 물질은 텅스텐을 대상으로 하였으며 표적시스템은 원통형구조를 가정하였다. 양성자 조사에 의한 텅스텐 물질의 핵파쇄반응으로 인한 내부발열을 모사하여 표적물내에서의 온도상승속도와 온도분포를 조사하였다. 계산결과 별도의 표적물에 대한 냉각시스템이 없는 상황에서 30∼37초만에 국부적으로 텅스텐의 온도가 녹는점 이상으로 상승하는 결과를 보였다. 따라서 고체표적물 시스템을 소멸처리로에서 사용하기 위해서는 표적물을 냉각시키기 위한 다각도의 방안이 모색되어야 한다.

• Proceedings of the Korean Nuclear Society Conference
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• 2003.05a
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• pp.127.2-127.2
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• 2003

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.39-42
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• 2002

The nuclear transmutation technology to Incinerate the long lived radioactive nuclides and produce energy during the incineration process is believed to be one or the best solutions. HYPER(${\underline{HY}}brid {\underline{P}}ower {\underline{E}}xtraction {\underline{R}}$eactor)is the accelerator driven transmutation system which is being developed by KAERI(Korea Atomic Energy Research Institute). Lead-bismuth(Pb-Bi) is adopted as a coolant and spallation target material. In this paper, we performed the thermal-hydraulic analysis of HYPER target using the commercial code FLUENT, and also calculated thermal and mechanical stress of the beam window using the commercial code ANSYS. It is found that there is an optimum value for the window diameter and the maximum allowable beam current can be increased to 17.3 mA for the inner diameter of windows, 40 cm. Finally, the other shapes such as uniform or scanned beam were considered. The results of FLUENT calculations show that the uniform type is preferable to the other shapes of the beam in terms of the window and target cooling and the maximum window temperature is lower than that of the parabolic beam by $58 ^{\circ}C$ for the beam current, 13 mA.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.915-920
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• 2001

A spent fuel problem has prevented the nuclear power from claiming to be a completely clean energy source. The nuclear transmutation technology to incinerate the long lived radioactive nuclides and produce energy during the incineration process is believed to be one or the best solutions. HYPER(Hybrid Power Extraction Reactor) is the accelerator driven transmutation system which is being developed by KAERI(Korea Atomic Energy Research Institute). Some major feature of HYPER have been developed and employed. On-power fueling concepts are employed to keep system power constant with minimum variation of accelerator power. A hollow cylinder-type metal fuel is designed for the on-line refueling concept. Lead-bismuth(Pb-Bi) is adopted as a coolant and Spallation target material. HYPER is a subcritical reactor which needs an external neutron source. 1GeV proton beam is irradiated to Lead-bismuth(Pb-Bi) target inside HYPER, and spallation neutrons are produced. When proton beams are irradiated, much heat is also deposited in the Pb-Bi target and beam window which separates Pb-Bi and accelerator vacuum. Therfore, an effective cooling is needed for HYPER target. In this paper, we performed the thermal-hydraulic analysis of HYPER target using FLUENT code, and also calculated thermal and mechanical stress of the beam window using ANSYS code.

• Biomedical Science Letters
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• v.2 no.2
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• pp.175-185
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• 1996

The mitogen-activated protein(MAP) kinase signal transduction pathway represents an important mechanism by which mitogen, such as serum and PMA, regulate cell proliferation and differentiation. Target substrates of the MAP kinase are located within several compartments containing plasma membranes and nucleus. We now report that serum addition induces proliferation of the P388 murine leukemia cell, but PMA does not, while both serum and PMA treatment cause translocation of the MAP kinase, mainly p42$^{mapk}$ isoform, from cytosol into the nucleus, which was monitored by immunoblot analysis using polyclonal anti-ERK1 antibodies. We investigated whether the MAP kinase was capable of phosphorylating c-Jun protein and GST-fusion proteins, the P562$^{kk}$N-terminal peptides (1-77 or 1-123 domain) of the T cell tyrosine kinase, using the partially purified MAP kinase by SP-sephadex C-50, phenyl superose and Mono Q column chromatography. We found that the partially purified MAP kinase was able to phosphorylate c-Jun protein and the GST-fusion protein expressed using E.coli DH5$\alpha$ which is transformed with pGEX-3Xb plasmid vector carrying of p562$^{kk}$N-terminal peptide-encoding DNA. These results imply that tyrosine kinase receptor/Ras/Raf/MAP kinase pathway is a major mechanism for mitogen-induced cell proliferation in P388 murine leukemia cell and that the various MAP kinase isoforms may have their own target substrates located in distinct subcellular compartments.