• Proceedings of the Korean Nuclear Society Conference
• /
• 2001.10a
• /
• pp.219.1-219
• /
• 2001

• Proceedings of the Korean Nuclear Society Conference
• /
• 1999.10a
• /
• pp.246-246
• /
• 1999

• Nuclear Engineering and Technology
• /
• v.41 no.2
• /
• pp.143-148
• /
• 2009

The increasing power and other demands on PWR fuel is leading to a demand for cladding that has low corrosion but that should also be robust with regard to mechanical behavior, impact of the irradiation environment and the coolant chemistry. The Optimized $ZIRLO^{TM}$ cladding is an evolutionary development of $ZIRLO^{TM}$ taking advantage of the long experience of the ZIRLO cladding but has significantly improved corrosion behavior. Recently, operation of Optimized ZIRLO to above 73 kWd/kgU has shown a reduction of the corrosion of almost 50%.

• Nuclear Engineering and Technology
• /
• v.41 no.2
• /
• pp.155-162
• /
• 2009

Since the 90's, EDF and AREVA-NP have irradiated, up to very high burnups, lead assemblies housing $M5^{(R)}$ cladded fuels. Post-irradiation examination of high burnup $UO_2$ pellets show an increase in the fission-gas release rate, an increase in fuel swelling, and formation of fission-gas bubbles throughout the pellets. Xenon abundances were quantified, and phenomena leading to this bubble formation were identified. All examinations provided valuable data on the complex state of the fuel during irradiation. They show the good behavior of these fuels, exhibiting various microstructures at very high burnups, none of which is likely to lead to problems during irradiation.

• Nuclear Engineering and Technology
• /
• v.41 no.2
• /
• pp.187-198
• /
• 2009

In this paper, three power ramp tests performed on high burn-up Re-crystallized Zircaloy2 - UO2 BWR fuel rods (56 to 63 MWd/kgU) within the SCIP project are simulated with METEOR and ALCYONE 3D. Two of the ramp tests are of staircase type up to Linear Heat Rates of 420 and 520 W/cm and with long holding periods. Failure of the 420 W/cm fuel rod was observed after 40 minutes. The third ramp test consisted of a more standard ramp test with a constant power rate of 80 W/cm/min up to 410 W/cm with a short holding time. The tests were first simulated with the METEOR 1D fuel rod code, which gave accurate results in terms of profilometry and fission gas releases. The behaviour of a fuel pellet fragment and of the cladding piece on top of it was then investigated with ALCYONE 3D. The size and the main characteristics of the ridges after base irradiation and power ramp testing were recovered. Finally, the failure criteria validated for PWR conditions and fuel rods with low-to-medium burn-ups were used to analyze the failure probability of the KKL rodlets during ramp testing.

• Archives of Plastic Surgery
• /
• v.35 no.6
• /
• pp.743-747
• /
• 2008

Purpose: Malignant changes of Marjolin's ulcer arising from chronic burn scar are rare. The majority of them are squamous cell carcinoma and basal cell carcinoma. Malignant fibrous histiocytoma is a deep seated pleomorphic sarcoma, which occurs principally as a mass of the extremities, abdominal cavity, or retroperitoneum in adults. Methods: We report a 58-year-old male patient who was admitted due to $3.5{\times}5cm$ chronic ulceration of anterior chest wall on the center of old burn scar. His scar had been occurred by boiling oil and treated with conservative treatment 45 years ago. Preoperative punch biopsy showed suspicious malignant changes and contrast enhanced chest CT showed well-defined, irregular shape enhancing lesion on anterior chest wall without intrathoracic metastasis. Results: The tumor was widely excised and defect was covered with skin graft without infection, necrosis and any other complication. The pathologic findings are compatible with malignant fibrous histiocytoma(storiform - pleomorphic type). The patient underwent 3 cycles of chemotheraphy. Although distant metastasis to the lung developed 6 months later and the patient died 9 month later, there was no local reoccurrence. Conclusion: Aggressive and early excision is needed because malignant fibrous histiocytoma has characteristics of high malignancy with a propensity for early and distant spread. Furthermore, the patient's education about disease entity and postoperative regular follow-up for local recurrence or metastasis is very important. To prevent malignancy from secondly healing burn scar, early skin graft is recommended for patients with deep second degree burn.

• Anxiety and mood
• /
• v.8 no.2
• /
• pp.93-98
• /
• 2012

Objective : Cortisol, a product of hypothalamus-pituitary-adrenal axis (HPA axis), is one of our defensive mechanisms in response to stress. The level of cortisol in the saliva is a major biomarker of the stress response by HPA axis and shows diurnal variation. We measured salivary cortisol level and its diurnal variation to compare the pattern of changes by degree of burn and Clinician-Administered PTSD Scale (CAPS) score. Methods : We measured the salivary cortisol levels of 37 subjects hospitalized in the burn center at our facility from March to June 2012. Salivary cortisol levels were measured at 6 : 00 AM and at 7 : 00 PM. All subjects were tested for CAPS to evaluate the severity of posttraumatic stress disorder and the Hamilton Depression Rating Scale to evaluate and to control the coexisting depression. Results : Factorial ANOVA test revealed that there was a statistically significant difference in terms of the effect of the interaction between the degree of burn and the patient's CAPS score. Unlike the mild burn group, in the severe burn group, the patients who had a low CAPS score didn't show a normal diurnal variation and the patients who had a high CAPS score showed the normal diurnal variation. After a few months follow up, we found a greater degree of psychiatric complications in severe burn patients that had a lower cortisol stress response. Conclusion : We suppose that the disappearance of the stress response changes in salivary cortisol seen in the severe burn group may be caused by an impaired stress response. Through followed observation of the subjects, this disruption of cortisol response may cause psychiatric problems afterwards.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.63 no.4
• /
• pp.490-494
• /
• 2014

In this paper, a design of high-speed power-off circuit and analysis. The incidence of high-dose transient radiation into the silicon-based semiconductor element induces the photocurrent due to the creation of electron-hole pairs, which causes the upset phenomenon of active elements or triggers the parasitic thyristor in the element, resulting in latch-up. High speed power-off circuit was designed to prevent burn-out of electronic device caused by Latch-up. The proposed high speed power-off circuit was configured with the darlington transistor and photocoupler so that the power was interrupted and recovered without the need for an additional circuit, in order to improve the existing problem of SCR off when using the thyristor. The discharge speed of the high speed power interruption circuit was measured to be 19 ${\mu}s$ with 10 ${\mu}F$ and 500 ${\Omega}$ load, which was 98% shorter than before (12.8 ms).

• Proceedings of the Korean Nuclear Society Conference
• /
• 2004.10a
• /
• pp.913-914
• /
• 2004

• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.05a
• /
• pp.339-340
• /
• 2005