SAMPLING BASED UNCERTAINTY ANALYSIS OF 10 % HOTLEG BREAK LOCA IN LARGE SCALE TEST FACILITY

SAMIRAN SENGUPTA,S. K. DUBEY,R. S. RAO,S. K. GUPTA,V. K RAINA 한국원자력학회 2010 Nuclear Engineering and Technology Vol.42 No.6

Sampling based uncertainty analysis was carried out to quantify uncertainty in predictions of best estimate codeRELAP5/MOD3.2 for a thermal hydraulic test (10% hot leg break LOCA) performed in the Large Scale Test Facility (LSTF)as a part of an IAEA coordinated research project. The nodalisation of the test facility was qualified for both steady state andtransient level by systematically applying the procedures led by uncertainty methodology based on accuracy extrapolation(UMAE); uncertainty analysis was carried out using the Latin hypercube sampling (LHS) method to evaluate uncertainty forten input parameters. Sixteen output parameters were selected for uncertainty evaluation and uncertainty band between 5thand 95thpercentile of the output parameters were evaluated. It was observed that the uncertainty band for the primary pressure duringtwo phase blowdown is larger than that of the remaining period. Similarly, a larger uncertainty band is observed relating toaccumulator injection flow during reflood phase. Importance analysis was also carried out and standard rank regression coefficientswere computed to quantify the effect of each individual input parameter on output parameters. It was observed that the breakdischarge coefficient is the most important uncertain parameter relating to the prediction of all the primary side parametersand that the steam generator (SG) relief pressure setting is the most important parameter in predicting the SG secondary pressure.

A techno-economic analysis of partial repowering of a 210 MW coal fired power plant

Samanta, Samiran,Ghosh, Sudip Techno-Press 2015 Advances in energy research Vol.3 No.3

This paper presents a techno-economic analysis of a partial repowering scheme for an existing 210 MW coal fired power plant by integrating a gas turbine and by employing waste heat recovery. In this repowering scheme, one of the four operating coal mills is taken out and a new natural gas fired gas turbine (GT) block is considered to be integrated, whose exhaust is fed to the furnace of the existing boiler. Feedwater heating is proposed through the utilization of waste heat of the boiler exhaust gas. From the thermodynamic analysis it is seen that the proposed repowering scheme helps to increase the plant capacity by about 28% and the overall efficiency by 27%. It also results in 21% reduction in the plant heat rate and 29% reduction in the specific $CO_2$ emissions. The economic analysis reveals that the partial repowering scheme is cost effective resulting in a reduction of the unit cost of electricity (UCOE) by 8.4%. The economic analysis further shows that the UCOE of the repowered plant is lower than that of a new green-field power plant of similar capacity.

SAMPLING BASED UNCERTAINTY ANALYSIS OF 10 % HOT LEG BREAK LOCA IN LARGE SCALE TEST FACILITY

Sengupta, Samiran,Dubey, S.K.,Rao, R.S.,Gupta, S.K.,Raina, V.K Korean Nuclear Society 2010 Nuclear Engineering and Technology Vol.42 No.6

Sampling based uncertainty analysis was carried out to quantify uncertainty in predictions of best estimate code RELAP5/MOD3.2 for a thermal hydraulic test (10% hot leg break LOCA) performed in the Large Scale Test Facility (LSTF) as a part of an IAEA coordinated research project. The nodalisation of the test facility was qualified for both steady state and transient level by systematically applying the procedures led by uncertainty methodology based on accuracy extrapolation (UMAE); uncertainty analysis was carried out using the Latin hypercube sampling (LHS) method to evaluate uncertainty for ten input parameters. Sixteen output parameters were selected for uncertainty evaluation and uncertainty band between $5^{th}$ and $95^{th}$ percentile of the output parameters were evaluated. It was observed that the uncertainty band for the primary pressure during two phase blowdown is larger than that of the remaining period. Similarly, a larger uncertainty band is observed relating to accumulator injection flow during reflood phase. Importance analysis was also carried out and standard rank regression coefficients were computed to quantify the effect of each individual input parameter on output parameters. It was observed that the break discharge coefficient is the most important uncertain parameter relating to the prediction of all the primary side parameters and that the steam generator (SG) relief pressure setting is the most important parameter in predicting the SG secondary pressure.

Palladium Nanoparticles Supported on MIL-101 as a Recyclable Catalyst in Water-Mediated Heck Reaction

Bhattacharjee, Samiran,Ahn, Wha-Seung American Scientific Publishers 2015 Journal of nanoscience and nanotechnology Vol.15 No.9

Solvothermal synthesis of Fe-MOF-74 and its catalytic properties in phenol hydroxylation.

Bhattacharjee, Samiran,Choi, Jung-Sik,Yang, Seung-Tae,Choi, Sang Beom,Kim, Jaheon,Ahn, Wha-Seung American Scientific Publishers 2010 Journal of nanoscience and nanotechnology Vol.10 No.1

<P>A Fe-containing metal-organic framework, Fe-MOF-74, was solvothermally synthesized using FeCl2.4H2O and 2,5-di-hydroxy-1,4-benzenedicarboxylic acid. Characterization was conducted by XRD, BET surface area measurement, FT-IR spectroscopy, TGA, and elemental analysis, which confirmed successful preparation of Fe-MOF-74 having an identical framework structure to that reported for MOF-74. Fe-MOF-74 was found to be an effective heterogeneous catalyst for the hydroxylation of phenol using H2O2 as an oxidant; 60% phenol conversion was achieved at 20 degrees C in water with 68 and 32% selectivity to catechol and hydroquinone, respectively. The effect of temperature, phenol/H2O2 mole ratio, catalyst quantity, and solvent on catalytic performance was discussed, and a reaction mechanism is proposed based upon the experimental results.</P>

Compressive and rarefactive dust ion-acoustic Korteweg–de Vries and modified Korteweg–de Vries solitons in a multi-component dusty plasma

Das Samiran,Das Dulal Chandra 한국물리학회 2023 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.83 No.4

Non-linear propagation of dust ion-acoustic (DIA) solitary waves in a multi-component plasma consisting of ions, Cairn’s distributed electrons and immobile dust has been investigated theoretically. Reductive Perturbation Technique (RPT) is used to derive Korteweg–de Vries (KdV) and modifed Korteweg–de Vries (mKdV) equations. Both compressive as well as rarefactive solitons (compressive in most of the situations) and only compressive mKdV solitons are found to exist for this plasma. Many interesting facts on amplitude as well as width of solitons are established by comparing KdV and mKdV solitons under the same set of diferent plasma parameters. The investigation is being done in two diferent modes and found that the non-thermal parameter (β) and the number of dust charge contained in a immobile dust particle (Zd) plays very important role in the formation of both KdV and mKdV solitons.

A new heterogeneous catalyst for epoxidation of alkenes <i>via</i> one-step post-functionalization of IRMOF-3 with a manganese(<small>II</small>) acetylacetonate complex

Bhattacharjee, Samiran,Yang, Da-Ae,Ahn, Wha-Seung Royal Society of Chemistry 2011 Chemical communications Vol.47 No.12

<P>A manganese(<SMALL>II</SMALL>) acetylacetonate complex has been immobilized to the metal–organic framework IRMOF-3 through a one-step post-synthetic route for the first time, providing an effective and recyclable heterogeneous catalyst for epoxidation of alkenes.</P> <P>Graphic Abstract</P><P>A novel route to bind manganese(<SMALL>II</SMALL>) acetylacetonate to IRMOF-3 through a one-step post-functionalization yields a highly selective, recyclable, and non-leaching heterogeneous catalyst for the epoxidation of alkenes. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1cc00069a'> </P>

Reinstatement of two varieties ofTrigonostemon viridissimusand sevensuperfluous lectotypifications in Indo-BurmeseTrigonostemon(Euphorbiaceae)

Tapas Chakrabarty,Samiran Panday,Anand Kumar 국립중앙과학관 2020 Journal of Asia-Pacific Biodiversity Vol.13 No.4

Two varieties,Trigonostemon viridissimusvar.chatterjii(Deb & Deka) N.P.Balakr. & Chakrab. andT. viridissimusvar.confertifoliusN.P.Balakr. & N.G.Nair, recently merged with the species are reinstatedherein. This article also points out thefirst effective lectotypifications of seven accepted names (or theirbasionyms) in Indo-BurmeseTrigonostemonBlume and their subsequent superfluous new lectotypifi-cations. These includeTrigonostemon diplotetalusThwaites,T. heteranthusWight,T. longifoliusBaill.,T. nemoralisThwaites,Baliospermum reidioidesKurz [basionym ofT. reidioides(Kurz) Craib],Clutia sem-perflorensRoxb. [basionym ofT. semperflorens(Roxb.) Müll.Arg.], andSabia viridissimaKurz [basionym ofT. viridissimus(Kurz) Airy Shaw].

Selective oxidation of tetralin over a chromium terephthalate metal organic framework, MIL-101

Kim, Jun,Bhattacharjee, Samiran,Jeong, Kwang-Eun,Jeong, Soon-Yong,Ahn, Wha-Seung Royal Society of Chemistry 2009 Chemical communications Vol.2009 No.26

<P>MIL-101, a mesoporous chromium terephthalate metal organic framework, was found to be an efficient heterogeneous catalyst for selective oxidation of tetralin to 1-tetralone using <I>tert</I>-butyl hydroperoxide or acylperoxy radicals generated <I>in situ</I> from trimethylacetaldehyde and O<SUB>2</SUB> as an oxidant.</P> <P>Graphic Abstract</P><P>The Cr(<SMALL>III</SMALL>) terephthalate, MIL-101 is an efficient heterogeneous catalyst for the oxidation of tetralin to 1-tetralone. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b902699a'> </P>

CrAPO-5catalysts having a hierarchical pore structure for the selective oxidation of tetralin to 1-tetralone

Kim, Jun,Bhattacharjee, Samiran,Jeong, Kwang-Eun,Jeong, Soon-Yong,Choi, Minkee,Ryoo, Ryong,Ahn, Wha-Seung The Royal Society of Chemistry 2010 NEW JOURNAL OF CHEMISTRY Vol.34 No.12

<P>A novel CrAPO-5 material having a unique microporous–mesoporous hierarchical pore structure (CrAPO-5H) was synthesized using an organosilane surfactant to conventional CrAPO-5 reaction mixture by a one-step hydrothermal process. The materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), N<SUB>2</SUB>-adsorption isotherm and UV-visible diffuse reflectance spectroscopy, and employed as a catalyst for the liquid phase oxidation of tetralin. CrAPO-5H produced higher activity than conventional microporous CrAPO-5. Acylperoxy radicals, <I>in situ</I> generated from trimethylacetaldehyde and O<SUB>2</SUB>, were more effective as oxidant than <I>tert</I>-butyl hydroperoxide (<I>t</I>-BuOOH); 88% conversion of tetralin with 97% selectivity to 1-tetralone was obtained with the former, whereas 57% conversion with 86% selectivity was achieved using the latter at 80 °C after 8 h. The effect of reaction temperature, Cr content, solvent, and the type of aldehyde employed for the <I>in situ</I> generation of acylperoxy radicals on catalytic performance was investigated. Activities of CrAPO-5H remained constant after 1st catalyst recycle. A hot filtration experiment coupled with a blank test revealed that oxidation proceeded mostly on Cr sites in the CrAPO-5H, but a minor contribution from trace amount of leached Cr could not be ruled out.</P> <P>Graphic Abstract</P><P>A novel CrAPO-5 material having a unique microporous–mesoporous hierarchical pore structure (CrAPO-5H) showed high activity and selectivity in the liquid phase oxidation of tetralin to 1-tetralone, and outperformed the conventional microporous CrAPO-5. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c0nj00493f'> </P>