• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회A
• /
• pp.1585-1589
• /
• 2007

The HANARO, a 30 MW multi-purpose research reactor in Korea, will be equipped with a neutron guide system, in order to transport cold neutrons from the neutron source to the neutron scattering instruments in the neutron guide hall near the reactor building. The neutron guide system of HANARO consists of the in-pile plug assembly with in-pile guides, the primary shutter with in-shutter guides, the neutron guides in the guide shielding room with dedicated secondary shutters, and the neutron guides connected to the instruments in the neutron guide hall. The functions of the in-pile plug assembly are to shield the reactor environment from a nuclear radiation and to support the neutron guides and maintain them precisely oriented. The primary shutter is a mechanical device to be installed just after the in-pile plug assembly, which stops neutron flux on demand. This paper describes the mechanical design of the in-pile plug assembly and the primary shutter for the neutron guide system at HANARO. The design of the guide shielding assembly for the primary shutter and the neutron guides is also presented.

• 한국압력기기공학회 논문집
• /
• 제12권1호
• /
• pp.23-29
• /
• 2016

The Second Shutdown Drive Mechanism (SSDM) provides an alternate and independent means of reactor shutdown. The Second Shutdown Rods (SSRs) of SSDMs are poised at the top of the core by the hydraulic force driven from a hydraulic system during normal operation. The rods drop by gravity when a trip is commended by a Reactor Protection System, Alternate Protection System, Automatic Seismic Trip System or operator by means of power off solenoid valves of hydraulic system. This paper describes the test results of seismic qualification of a prototype SSDM hydraulic system to demonstrate that its structural integrity and operability (functionality) are maintained during and after seismic excitations, that is, an adequacy of the SSDM design. From the results, this paper shows that the SSDM hydraulic system satisfies all its design requirements without any malfunctions during and after seismic excitations.

• 한국도서관정보학회지
• /
• 제46권4호
• /
• pp.325-354
• /
• 2015

정보거버넌스는 정보 컴플라이언스 요건을 충족시키고, 정보 가치를 극대화하는 한편 정보 위험을 통제하기 위한 통합적 접근법이다. 기업정보관리에서는 정보가 가진 활용가치뿐 아니라 보유에 따른 위험을 함께 고려해야 한다. 특히 해외 시장에 진출한 기업들이 소송과 전자증거개시에 대비하려면 건실한 기록정보관리에 토대를 둔 정보거버넌스의 도입이 시급하다. 이 연구는 미국 법조계에 영향력을 가진 세도나 컨퍼런스의 정보거버넌스 원칙을 실천적 관점에서 분석하여 기업의 정보거버넌스 구축방안을 제시하기 위한 것이다. 이 원칙을 실무에 적용할 수 있는 통제 기준으로 재구성한 후 이러한 통제 기준을 정보거버넌스의 업무 영역별로 배치하고 이를 해석함으로써 정보거버넌스의 구축과 운영상의 시사점을 제시하였다.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2002년도 학술대회지
• /
• pp.43-46
• /
• 2002

The HANARO, multi-purpose research reactor, 30 MWth open-tank-in-pool type, is under 24 MWth of power operation since it reached to the initial critical in February, 1995. Many useful experiments should be safely performed to activate the utilization of the HANARO, but there is a radioactive risk of using the HANARO. To reduce the risk, a test facility, which is not reacted by nuclear fuel, is being developed to simulate similar flow characteristics with the HANARO. This paper describes the computational flow analysis to determine each shape of simulating fuels for simulating the flow similarities of 36 elements hexagonal fuels assembly and 18 elements circulating fuels assembly loaded in HANARO. The shares of orifices were determined by the trial and error method and the structural integrities of them were verified by the finite element method assuming that the flow rate and pressure differences of reactor core are constant. The analysis results will be verified with the results of the flow test to be performed after the installation of this test facility.

• 한국소음진동공학회논문집
• /
• 제26권5호
• /
• pp.552-558
• /
• 2016

A control rod drive mechanism(CRDM) is a reactor regulating system, which inserts, withdraws or maintains a control rod within a reactor core to control the reactivity of the core. The CRDM for Jordan Research and Training Reactor with 5MW power has been designed and fabricated based on the HANARO’s experience through KAERI and DAEWOO consortium. This paper describes the seismic test results to demonstrate the operability, the drop performance and the structural integrity of CRDM during or after seismic excitations. The seismic tests are carried out under 5 OBE and 1 SSE loads at three Test Rigs simulating the reactor structure and the pool top. From the tests, the CRDM is smoothly driven without a malfunction of stepping motor under OBE load. The pure drop time under OBE and SSE loads is measured as 1.169s and 1.855s to meet the design requirement. Also, it is found that the CRDM maintains the structural integrity without a change of the function and natural frequency before and after seismic loads.

• Journal of Microbiology and Biotechnology
• /
• 제17권4호
• /
• pp.600-603
• /
• 2007

The effect of a water-miscible ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate $([BMIM][BF_4])$, on the horseradish peroxidase (HRP)-catalyzed oxidation of 2-methoxyphenol (guaiacol) with hydrogen peroxide $(H_2O_2)$ was investigated. HRP maintains its high activity in the aqueous mixtures containing various concentrations of the ionic liquid and even in 90% (v/v) ionic liquid. In order to minimize the effect of solution viscosity on the kinetic constants of HRP catalysis, the enzymatic reactions in the subsequent kinetic study were performed in water-ionic liquid mixtures containing 25% (v/v) ionic liquid at maximum. As the concentration of $[BMIM][BF_4]$ increased for the oxidation of guaiacol by HRP, the $K_m$ value increased with a slight decrease in the $K_{cat}$ value: The $K_m$ value increased from 2.8 mM in 100% (v/v) water to 22.5mM in 25% (v/v) ionic liquid, indicating that ionic liquid significantly weakens the binding affinity of guaiacol to HRP.

• Journal of Microbiology and Biotechnology
• /
• 제15권2호
• /
• pp.234-238
• /
• 2005

Glucose oxidase was immobilized on the carboxylated multi-wall carbon nanotubes (MWNT-COOHs) in the presence of a coulping reagent, 1-ethy1-3-(3-dimethylaminopropy1) carbodiimide. Significant amounts of glucose oxidase were also immobilized on MWNT-COOHs without the coupling reagent. Various conditions for the immobilization of glucose oxidase were optimized. Optimal pH for the maximal activity of the immobilized glucose oxidase shifted to 7 from the optimal pH of 6 for the maximal activity of free enzyme due to the carboxy1 groups on the surface of MWNT-COOHs. An electrode of graphite rod with a diameter of 6 mm was fabricated using the immobilized glucose oxidase. The cyclic voltammetry study of the enzyme electrode revealed that the oxidation of glucose and subsequent transfer of electrons from the oxidation of glucose to the electrode were possible by the immobilized glucose oxidase without a mediator, implying that the enzyme electrode can be utilized for the development of biofuel cells.

• 한국소음진동공학회논문집
• /
• 제26권6_spc호
• /
• pp.697-704
• /
• 2016

The second shutdown drive mechanism (SSDM) that is classified into seismic category I as an active mechanical equipment shall maintain the structural integrity and its designed inherent safety functions during and/or after normal operation, anticipated operational occurrences, accidents and seismic occurrences. Therefore, not only a structural integrity assessment through numerical analyses but also a qualification test by using the prototype SSDM shall be conducted to verify the adequacy of the SSDM design. This paper describes a sort of seismic qualification test of the prototype SSDM to demonstrate that the structural integrity and operability (functionality) of SSDM are maintained during and/or after seismic excitations. From the results, this paper shows that the SSDM satisfies all design requirements without any malfunctions during and after the seismic test.

• 영미문화
• /
• 제9권1호
• /
• pp.91-112
• /
• 2009

Referring to John Irving's 2001 published fiction The Fourth Hand, the publisher commented, "It seems, at first, to be a comedy, perhaps a satire, almost certainly a sexual farce. Yet, in the end, it is as realistic and emotionally moving as any of Mr. Irving's previous novels." In his early six novels, John Irving shows the world suffused with grief and deception. But his novels finally turn out also as a comic and robust novel. The writer's success in achieving this thick description of the contradictory modern world is largely due to his development of the idea of the flawed hero. Despite loss, sadness and abandonment, Irving's heroes maintain classical heroic traits such as intelligence, tenderness, protectiveness, strength, bravery, sense of humor, independence, attractiveness. In this article, I tried to emphasize these graces potent in Irving's heroes as the most attractive and influential device for the writer's consistent popularity among the general public. The cinematization of his four fictions attest to audience's sympathy toward rewarding vulnerability and truthful exaggeration in the depiction of Irving's heroes. By taking full responsibility for their own fate despite having the flaws, Irving's protagonists still appeal to many readers as heroes resilient in a modern chaotic world without losing their graces.

• Nuclear Engineering and Technology
• /
• 제55권12호
• /
• pp.4477-4490
• /
• 2023

Fuel locking mechanisms (FLMs) are essential in upward-flow research reactors to prevent accidental fuel separation from the core during reactor operation. This study presents a novel design concept for a remotely controlled plate-type nuclear fuel locking mechanism. By employing electromagnetic field analysis, we optimized the design of the electromagnet for fuel unlocking, allowing the FLM to adapt to various research reactor core designs, minimizing installation space, and reducing maintenance efforts. Computational flow analysis quantified the drag acting on the fuel assembly caused by coolant upflow. Subsequently, we performed finite element analysis and evaluated the structural integrity of the FLM based on the ASME boiler and pressure vessel (B&PV) code, considering design loads such as dead weight and flow drag. Our findings confirm that the new FLM design provides sufficient margins to withstand the specified loads. We fabricated a prototype comprising the driving part, a simplified moving part, and a dummy fuel assembly. Through basic operational tests on the assembled components, we verified that the manufactured products meet the performance requirements. This remote-controlled micro locking mechanism holds promise in enhancing the safety and efficiency of plate-type nuclear fuel operation in upflow research reactors.