• Title/Summary/Keyword: NDA

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UK Civil Nuclear Decommissioning, a Blueprint for Korea's Nuclear Decommissioning Future?: Part II - UK's Progress and Implications for Korea

  • Foster, Richard I.;Park, June Kyung;Lee, Keunyoung;Seo, Bum-Kyoung
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.20 no.1
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    • pp.65-98
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    • 2022
  • The nuclear legacy that remains in the United Kingdom (UK) is complex and diverse. Consisting of legacy ponds and silos, redundant reprocessing plants, research facilities, and non-standard or one-off reactor designs, the clean-up of this legacy is under the stewardship of the Nuclear Decommissioning Authority (NDA). Through a mix of prompt and delayed decommissioning strategies, the NDA has made great strides in dealing with the UK's nuclear legacy. Fuel debris and sludge removal from the legacy ponds and silos situated at Sellafield, as part of a prompt decommissioning strategy for the site, has enabled intolerable risks to be brought under control. Reactor defueling and waste retrievals across the Magnox fleet is enabling their transition to a period of care and maintenance; accelerated through the adopted 'Lead and Learn' approach. Bespoke decommissioning methods implemented by the NDA have also enabled the relevant site licence companies to tackle non-standard reactor designs and one-off wastes. Such approaches have potential to influence and shape nuclear decommissioning decision making activities globally, including in Korea.

Study on the Feasibility of Utilization of Pine Cone Byproduct as a Natural Deodorizing Agent for Composting Process (퇴비화 시설용 천연 악취저감제로의 잣송이 부산물의 활용 가능성에 관한 연구)

  • Chun, H.S.;Kwag, J.YH.;Ga, C.H.;Park, J.I.;Kim, C.H.;Ra, C.S.
    • Journal of Animal Environmental Science
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    • v.13 no.2
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    • pp.129-138
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    • 2007
  • A natural deodorizing agent (NDA) was made using pine cone byproduct, and its effects on malodor emission and composting were analyzed in this study. NDA was manufactured by mixing pine cone byproduct with three species of microorganisms and water containing mineral nutrients and molasses, and then by incubating for 48 hours at $30^{\circ}C$. Lab scale experiments were done with three treatment groups, T1 (control, sawdust treatment), T2 (microorganisms and sawdust treatment group), and T3 (NDA and sawdust treatment group). During composting, temperatures reached over $55^{\circ}C$, a minimum temperature for the inactivation of pathogenic microorganisms. No differences were found in physicochemical composition of compost among treatments. However, it was observed that over usage of NDA could obstruct temperature increase, since the biodegradation rate of organic matter of NDA was relatively low, Nitrogen loss due to ammonia gas emission, which normally happens during composting, was reduced by using NDA, and hence the nitrogen level of final compost was higher in T3 than in others. During experiment, it was found that ammonia gas emission was entirely lasted through compositing duration, but the $CH_3SH$ and $H_2S$ gases were produced only at early stage of composting. The ammonia concentration trapped in $H_2SO_4$ solution during 31 days of composting in T1, T2 and T3 was 12,660mg/L, 11,598mg/L and 7,367mg/L, respectively, showing distinguishable reduction of ammonia gas emission in T3. The emissions of $CH_3SH$ and $H_2S$ gases were also remarkably reduced in T3. Based on these obtained results, usage of the deodorizing agent made with pine cone byproduct could reduce the emission of malodor during composting, without any deterioration of compost quality.

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Continuous Surveillance and Diagnostics System Using Neural Network (인공 신경 회로망을 이용한 핵물질 거동 감시 시스템 개발)

  • 최재형;한명철;박영수;김호동;홍종숙
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.1182-1185
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    • 1995
  • This paper presents a novel technology for unattented continuous monitoring of radioactive material in hot cell environments. In this monitoring system, the surveillance camera data and NDA data are time synchronized and integrated into the same dimension through data processing. The integrated information is then fed into a neural network to generate diagnostics through data processing. the integrated information of the concept is tested for a spent nuclear fuel transprotation in an operational hot cell at KAERI. The presented integral part of the multi-sensory system and the analytical paradigm may provide an effective technologyical alternative for safeguarding new conceptual hot cell facilities, namely the Dupic facility.

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Maximum Likelihood SNR Estimation for QAM Signals Over Slow Flat Fading Rayleigh Channel

  • Ishtiaq, Nida;Sheikh, Shahzad A.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.11
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    • pp.5365-5380
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    • 2016
  • Estimation of signal-to-noise ratio (SNR) is an important problem in wireless communication systems. It has been studied for various constellation types and channels using different estimation techniques. Maximum likelihood estimation is a technique which provides efficient and in most cases unbiased estimators. In this paper, we have applied maximum likelihood estimation for systems employing square or cross QAM signals which are undergoing slow flat Rayleigh fading. The problem has been considered under various scenarios like data-aided (DA), non-data-aided (NDA) and partially data-aided (PDA) and the performance of each type of estimator has been evaluated and compared. It has been observed that the performance of DA estimator is best due to usage of pilot symbols, with the drawback of greater bandwidth consumption. However, this can be catered for by using partially data-aided estimators whose performance is better than NDA systems with some extra bandwidth requirement.

NASAL DEVIATION IN PATIENTS WITH MANDIBULO-FACIAL ASYMMETRY (안모 비대칭환자의 두부정중선에 대한 비부의 편위)

  • Park, Ji-Hwa;Son, Seong-Il;Jang, Hyun-Jung;Kwon, Tae-Geon;Lee, Sang-Han
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.27 no.2
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    • pp.151-159
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    • 2005
  • The purpose of this study was to evaluate the nasal deviation in mandibular prognathism with mandibulo-facial asymmetry. There were 40 patients whose mandibular prognathism with/without facial asymmetry were treated with orthognathic surgery from March 2002 to October 2003. The Group A(n=20) had a mandibulo-facial asymmetry over 6mm menton deviation in cephalogram PA and the Group B(n=20) had a mandibular prognathism. The preoperative frontal photograph, cephalogram PA and three dimensionalcomputed tomography(divided in hard tissuse image and soft tissue image) of two group was evaluated NDA(nasal deviation angle) and MDA(mandibular deviation angle). The NDA was statistical difference between asymmetry Group A and symmetry Group B(p<0.01), and was deviated in affected side of asymmetry. The MDA were also statistical difference between Group A and Group B(p<0.01), however the measurements of MDA between the frontal photograph, 3D-CT and cephalogram PA were similar to each others. The low correlation of NDA between frontal photograph and cephalogram PA in Group A and B demonstrate that we couldn't assess nasal deviation in cephalogram PA. It could be concluded that patients with mandibulo-facial asymmetry have a nasal deviation and clinician must remember this fact when they assess and treat patients.

Effects of Damage by Brown Planthopper at Ripening Stage on Yield and Quality of Rice (벼 등숙기 벼멸구 피해가 수량 및 품질에 미치는 영향)

  • Lee, Jong-Hee;Yeo, Un-Sang;Kwak, Do-Yeon;Kim, Joon-Hwan;Song, Yu-Cheon;Kim, Choon-Song;Shin, Moon-Sik
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.spc1
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    • pp.73-76
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    • 2006
  • This study was carried out to investigate the change yield and grain quality in rice caused by damages of brown planthopper (Bph) on major agronomic traits at the ripening stage. A major agronomic traits such as culm length, panicle length, number of panicle and number of grain per panicles was no-significant difference compared hopperburn area (HBA) and moderately damaged area (MDA) by brown planthopper with non-damaged area (NDA). but, the ripeing ratio and yield in HBA and MDA was significantly decreased. The perfect rice of brown rice in HBA and MDA was also lowered than the NDA and the immatured grain among imperfect rice in damaged area by BPH was significantly increased than in the NDA. Among the traits related with palatability of cooked rice, the amylose content was not affected by damage of brown planthopper, whereas, the protein content was significantly increased in the HBA and MDA. additionally, Peak viscosity in HBA and MDA is lower than the NDA, and setback was increased. In most cases, there was negative on yield and grain quality by the damage of brown planthopper at the ripening stage. Thus, the rice product harvested in damaged area should be separated with that in non damaged area for grain market quality of milled rice.