JOUAL Of ULEA And eated TEHOLOGIES, Vome, o., December 004 SALIG ITEIA FO TEHA ESEAH EATO THEMALHYDAULI SYSTEMS Kazem Faradi Teran esearc eactor esearc Grop, cear esearc enter Atomic Enery Oranization of Iran (AEOI, Teran-Iran e-mai:kfaradi@aeoi.or.ir ABSTAT Scain criteria for Teran esearc eactor, a Materia Testin eactor, nder natra as we as forced circation is derived based on fid-to-fid modein. Usin tese criteria, te basic caracteristics of scae mode are determined. Te aforementioned criteria are sc as power density, temperatre rise, mass fx, and size of te mode. In enera, nmbers of scain aws are ess tan te basic nknown caracteristics variabes of te mode and conseenty, many scae modes can be estabised for te system nder consideration. Te coice of mode desiner as a sinificant effect on fina mode and its distortion. In Teran esearc eactor (T, te tickness of fe pates and te widt of cooant fow rate are very tin, indeed. For increasin tese two parameters tat may ead to an efficient and a better mode; two strateies are to be empoyed. Eiter sin different cad materias from tose tat are sed in te prototype or canin type of te cooant fid. ABSTAK Kriteria penskean ntk eaktor Penyeidikan Teran (T, seba eaktor Pejian Baan, ketika edaran (penyejk biasa mapn dipaksa adaa diterbitkan berdasarkan kepada permodean cecair ke cecair. Mennakan kriteria-kriteria ini, cirri-ciri asas ske mode ini ditentkan. Kriteria yan yan diterankan sebem ini adaa merpakan saperti ketmpatan kasa, s naik, fk jisim dan saiz sesat mode. Ummnya, banyak km penskean adaa kran dari yan asas pemboeba ciri an sesat mode dan natijanya, banyak mode skaa boi dibannkan ntk sistem yan dipertimbankan. Pemiian perekaan bentk mode mempnyai kesan yan jeas kepada mode akir dan kekranannya. Daam T, teba pat baan api dan ebar kadar airan penyejk adaa sebenarnya sanat nipis. Bai menaikan keda parameter ini yan membawa kepada mode yan cekap dan baik, da stratei adaa dipakai. samada mennakan baan sat yan berbeza dari yan dinakan daam prototaip ata menba jenis bendair penyejk. Keywords:Teran esearc eactor, Scain criteria, fid-to-fid scain. ITODUTIO Teran researc reactor is a poo-type non-omoeneos researc reactor wit maximm of 5MW operatin power. Te cooin system is consists of te primary oop, secondary oop toeter wit a cemica prification system. Te primary oop removes te dissipated eat in core into te atmoere via secondary oop wit te aid of a se and tbe eat excaner. Te 38
JOUAL Of ULEA And eated TEHOLOGIES, Vome, o., December 004 cooant is ravity driven and passed tro te acin (cooant canne between te fe pates and ten towards te exitin pipe of te poo and ten pored into te od-p-tank. Tereafter, te cooant passed tro te se of te eat excaner and after oosin te eat by te secondary oop retrns into te poo to compete te circe. Te enera arranement of te reactor cooin circit is sown scematicay in Fi. a, and a typica standard fe eement is sown in Fi. b. Amon te interested probems reardin te T is te investiation of permissibe variations of te terma ydraic variabe sc as temperatre, mass rate of fow and power for different reactor power and te eve of safety in te event of an accident. Te reators aways reire te extensive vaidation of terma ydraic parameters of te T. On te oter and testin and vaidatin te terma ydraic parameters via a system wit rea dimension is practicay nreasonabe if not impossibe. Terefore te scaed mode is sed for vaidatin te terma parameters of te T core. In view point of terma ydraic tere wi be a simiarity between te scaed mode and prototype wen te conservation eations are te same between te scaed mode and prototype. In oter words, tey obey te same non-dimensiona conservations eations. Fi. : a. Te enera arranement of te reactor cooin circit. 39
JOUAL Of ULEA And eated TEHOLOGIES, Vome, o., December 004 Fi. : b. Typica standard fe eement Impementin te obtained rests from te scaed mode into te prototype wi be acieved by empoyin te scain criteria. Indeed, tese scain criteria are te dimensioness rops tat tese ratios mst be nity were te ratios of mode to prototype are considered. Te accracy and appicabiity of te obtained experimenta rests and ence te discssion of te data are a depend on te scain criteria pon wic te scaed mode was basicay desined (Wite, 994. Based on tis fact, severa stdies were carried ot so far. Tese stdies were aimin to acieve a better and more fexibe simiitde criteria. arbiener and dnik (969 presented inear scain. In teir scain, te ratio of te ent rested in ratios of area and vome in and 3, reectivey. aavandi (979 proposed vometric (time preservin for modein ncear power pant components. In te time preservin modein, te eit of te mode and prototype are taken to be ea. Isii and Kataoka (984 deveoped scain criteria for twopase fow. Tey obtained scain criteria for cooin systems of te pressrized water reactor (PWs for natra convection sine pase and two-pase fow. Kocamstafaoari and Isii (987 deveoped scain criteria for modein transient fow from sine pase to two-pase fow. Since te T primary cooin system resembes to te primary cooin systems of te PWs, it is possibe to appy te Isii s scain criteria for desinin a scaed mode. Te appied scain criteria for sine as we as two-pase fow are iven in Tabe. 40
JOUAL Of ULEA And eated TEHOLOGIES, Vome, o., December 004 METHODS Te Initia Mode onsiderin tat te pressre in te mode and prototype are aike. Aso, te temperatre imitations and te type of caddin are identica in bot te mode and prototype. Upon coosin te time preservin scain mode and benefitin from criteria iven in Tabe, one may obtains t / ( T Te dimensions of mode are iven in Tabe. Te eat transfer ratio is obtained from te we-known Ditts-boter correation 0.8 0.4 0.03e Pr ( d 3( 0.8 0. Since te ratio of vometric power of scaed mode to prototype eate to nity, te power enerated in te mode Q m may be obtained in accordance wit foowin reations: ( Q/ V m (4 ( Q/ V p ( Q/ V m (5 ( Q/ V p were Q p is te enerated power in te prototype (5MW and is te ratio of nmber of fe pates in te mode to tat of prototype. Te dimensiona determination of te primary cooin system can be done by takin into consideration te eaity of F in te foowin manner: Te tota pressre-drop in te mode=te tota pressre-drop in te prototype Once te dimensions of te individa components in te primary cooin oop and te core operatin point are obtained wit te aid of aforementioned reations, te ecifications of te eat remova sorce may be cacated. Tis is done by assmin tat in te steady state te enerated eat ea to eat remova. In tis manner te diameter of te pipin wi be determined in sc a way tat te eaity of F wi be vaid. 4
JOUAL Of ULEA And eated TEHOLOGIES, Vome, o., December 004 4 Tabe : Scain criteria for sine and two-pase fow. Dimensioness rop Pertain scain criteria SUBSIPTS m mixtre m mode p prototype r ratio of mode to prototype s soid sine pase two-pase 4 f f f f PH d d f sb f sb SUB f f fr j j D V V c c.5 0 fi i fi a a x x d f.5 O i O a a x K e e SUB PH x x
JOUAL Of ULEA And eated TEHOLOGIES, Vome, o., December 004 43 P P E ( 4 P P d d St s s T s s K K B ( Ps s s Ps s s si T T Q i i F K d f F Tabe : Scain criteria for sine and two-pase fow (contined. Dimensioness rop Pertain scain criteria Tabe : Dimensions of te prototype and mode. Specifications Initia mode Mode wit metano eapfff f npe nemip.5*60*65 mm 3.567*60*65 mm ffemi nmpe aoi.7 mm.64 mm snaapp f npe nemipf mber of cooant cannes Temperatre difference between inet and otet 8.6 5.6 rfenapipn nfapp 78.7 Kw/m 3 8.4 Kw/m 3 Tota enerated power 9.86Kw 60.Kw Tota pressre drop 30.48m 60.96m ffemi amff efa pmip 0.7 K/s.336K/s ffemi amff efni ip nfpp.690m/s.39m/s T T
JOUAL Of ULEA And eated TEHOLOGIES, Vome, o., December 004 Knowin te fact tat in te above scain, te obtained scain is vometric. Aso, te ratios between mode and prototype for a dimensioness rops became nity and ence one can say tere wi be no distortion in te fina rests. From E. 5, it is cear tat te nmber of fe pates depends on te desiner decision. In oter word, increasin te nmber of fe pates wi increase te tota power in te scaed mode. Tabe 3: Typica fids ffied te scain criteria. ooant of te mode Temperatre ( Density (K/m 3 ests (E. Heptane 300 675.6483 4.04638 305 679.67078 4.07059 30 67.55958 4.09550 Hexane 65 683.673 3.4377 70 679.666 3.453 75 675.5900 3.47403 Pentane 65 654.596 3.937 70 649.6880 3.95009 75 645.0658 3.97877 Metano 300 790.8779 0.9873 305 785.47955 0.99403 30 780.03658.00098 35 774.4846.0087 Fid-To -Fid Modein One ot to pay attention to two points reardin te defined scaed mode in te previos section. First of a, te widt of cooant canne (te ace provided between eac pair of fe pates tat is ea to.7 mm and secondy te tickness of fe pates tat is ea to.5 mm. Sod one aims at providin a scaed mode wit wider cooant canne and ticker fe pates for te ease of experimentation, ten te provided mode mst be modified accordiny. For providin sc a mode, in tis section, fid-to- fid scain wi be considered toroy. In enera, in fid-to-fid modein (Amad, 973: Yadiaro, 994 te cad materia as we as te type of fid empoyed in te mode is different from te prototype. By seectin time ratio for sine pase as we as two-pase scain criteria in te form of foowin reation 0.5 ( t ( t 6( One may obtain te reations iven beow from Tabe. 7( 0.5 ( ( 8( 0.5 0.5 ( ( s 9( s ps 0.5 0.5 ( d ( d s p 44
JOUAL Of ULEA And eated TEHOLOGIES, Vome, o., December 004 ( s f 0.5 ( ( s f pf ( s 0.5 ps ( It is cear tat except s te oter parameters for te sine pase and two-pase fow are identica. Terefore, for keepin in te transient from sine pase to two-pase fow, te foowin reation mst be satisfied. f pf ow, scaed mode fid mst be seected in sc way tat te above condition ffied. Moreover, te seected mode fid mst ave te foowin caracteristics: It mst be pysicay resistant to te temperatre and be stabe. It sod ave te east tendency to react wit metas. It sod not expode nor be famin. Tabe 3 provides a few typica fids tat may ffi te scain criteria. De to ow boiin point of freon famiy at atmoeric pressre, it is not a sitabe seection. However, by seectin metano and considerin, ecifications of te scaed mode wi be determined. Te ecifications are sown in Tabe. Few points are worty to note. Firsty, in te cacation for te cad, te materia of A606 is considered. Secondy, te widt of cooant canne d and tickness of fe pates d are increased in sc a way tat te reations d d 4.395 d. 3784 od tre. Tirdy, te inet s temperatre into te mode is very important parameter and mst be considered carefy. In te modes were te fid remains in te sine-pase condition, te difference between inet and otet temperatre is vita to be considered. Te inet temperatre can be seected arbitrary as on as te fid remains in te sine-pase condition. However, in te present mode were tere is a transient between te two pases, conseenty te inet temperatre cod not be assined any arbitrary vae. In fact te inet temperatre wi be determined from te deree of inet fid sb-cooin. Te deree of sb-cooin of metano is cacated from te reation ( s sb SUB (3 f Tabe 3 provides te rests of reation for different temperatres. Since it is not possibe to obtain nity for te reation mentioned above, te rests tat may be obtained from te scaed mode wi be te distorted one. Te eve of distortion wi depend on weter from reation 0 or reation. Wen s 45 s is cacated is rested from te reation nmber 0, in oter words, it is cacated from te sine-pase reation. Ten as on as te fid in te scaed mode remains in te sine-pase tere wi be no distortion. However, in two-pase fow, te
JOUAL Of ULEA And eated TEHOLOGIES, Vome, o., December 004 parameter s wi not be ea to te one obtained from reation 0 and as a conseence tere wi an error in te temperatre as we as veocity. Te amont of error in veocity wi be determined by sbstittin ( in pc iven in Tabe. s ( ( EO ( pf f (4 Te error rested from T wi be cacated by te foowin reation ( T ( T EO ( T f pf (5 Wen s rested from te reation, in oter words, from a two-pase reation, as a conseence tere wi be error in veocity and temperatre considerin sine-pase fow. Te amont of distortion wi be cacated in a simiar manner as as been done before. Te onsidered Sampe Te transient reime of startin-p of te T wi be anayzed and compared to bot te mode and prototype. Before start-p of te reactor, te fe eements and cooant avin identica temperatre tat is ea to te temperatre of te srrondin (bk of te cooant in te core. Upon startin-p of te reactor, te eat wi be enerated in te fe pates and te cooant passed tro te cooin cannes to remove te eat. Assmin te temperatre increasin wit time from a zero vae to te predetermined. We are aimin at investiatin transient temperatre distribtion of te cooant fow. Te fid temperatre distribtion for te prototype is sown in Fi.. Aso te crves for temperatre distribtion in te mode are sown in Fi. 3. For sowin te eve of error in te temperatre, te crves for prototype and mode are compared and are sown in dimensioness form in Fi. 4. ESULTS AD DISUSSIO Scain criteria for te T primary oop were stdied. Since te dependent variabes of te scaed mode are more tan te eations pertain to scain criteria, conseenty, nmeros different modes cod be sed for a system. In oter words, te mode cod be desined in nmber of ways. However, different factors wod imit te fina desin of te mode. Te aforementioned factors incde, famiiarity wit te pysica aws tat predominate te system to be a scaed mode and te reated matematica reations. Te pysica properties of different components invoved in te mode sc as.te reasonabe and practica seection K,, p of te dimensions of te mode as we as seection of reasonabe operatin rane of te mode and finay te faciities provided by te aboratory. In desinin a scaed mode and findin te reated scain criteria for te T cooin system te aforementioned factors were taken into consideration. In tis paper it is sown tat ow to dea wit tese criteria and to provide te dimensions of te scae mode. 46
TEMPEATUE ISE ( deree JOUAL Of ULEA And eated TEHOLOGIES, Vome, o., December 004 Once te scain criteria for te T and conseenty te dimensions of te scae mode are known, ten in te next step te constrction and operation of te mode wod bein. Tis is aim at providin necessary experimenta data to vaidate te terma correations as we as te safety marins of te T. Tese experimentations are reired to ffi and compete te Safety Anaysis eport (SA, AEOI, 989 of te T demanded by te IAEA for aowin frter safe operation of te T. Frame 00 6 Feb 006 4 x = x = 0.8 0 x = 0.6 8 6 x = 0.4 4 x = 0. 0 0 3 4 5 TIME ( second Fi.. Fid temperatre distribtion in te prototype 47
TEMPEATUE ISE ( deree TEMPEATUE ISE ( deree JOUAL Of ULEA And eated TEHOLOGIES, Vome, o., December 004 Frame 00 3 Feb 006 x = 8 7 x = 0.8 6 5 x = 0.6 4 3 x = 0.4 x = 0. 0 0 3 4 5 TIME ( second Fi.3. Fid temperatre distribtion in te mode Frame 00 3 Feb 006 x = 0.9 0.8 0.7 0.6 x = 0.8 x = 0.6 POTOTYPE MODEL 0.5 0.4 0.3 0. x = 0.4 x = 0. 0. 0 0 3 4 5 TIME ( second Fi.4. omparison of temperatre distribtion between te prototype and mode 48
JOUAL Of ULEA And eated TEHOLOGIES, Vome, o., December 004 Fid-to-fid scain tat ave been extended and appied in te present work deveoped by Kocamstafaoari and Isii (987. Tey sed te fid-to-fid scain for redced pressre in teir work in an attempt to simate te Sma Break Loss of ooant Accident (SBLOA. In te present work te main aim was to deveop a mode by sin fid-to-fid scain tat cod provide a feasibe and practica dimensions for constrctin a scae mode. Benefitin from te fid-to-fid mode rested in a mode wit wider cooant canne and ticker fe pates as compared to te oriina one. Te metod presented in tis paper cod be sed in desinin researc scae modes, primary cooant system of te T, primary scain mode for eat excaners, etc. and aso a wide rane of appications in oter reated brances of science and enineerin. OLUSIOS Wit view of east strctra canes in te process of te T pradin and coosin te ravity driven ine to be caned effectivey tat rests in power increasin. Aso, to vaidate te safety marins for bot present operatin condition and in te case of power pradin constrction of a terma test oop is a mst. In te T, te tickness of fe pates and te widt of cooant canne are very narrow. Increasin tese two parameters ead to a more feasibe and practica scae mode. As a conseence, two strateies are to be appied. Eiter, sin different cad materias from tose tat sed in prototype or canin te type of cooant fid. In tis reect a compter proram was deveoped in order to provide practica and feasibe dimensions for constrctin a scaed mode of te T primary cooin systems incdin te rectanar core of te reactor. Based on te simiarity anaysis deveoped oriinay by Isii and Kataoka (984 and Kocamstafaoari and Isii (987 a mode was obtained in wic te widt of cooant canne was increased from.7 mm to mm. Tis obviosy sows te capabiity of te proram tat incdes te properties of nmeros fid properties tat satisfies te condition of scain criteria. AKOWLEDGEMET Te ator expresses is indebtedness and appreciation to Kai Hossini Poor oani, a desin enineer from University of Sarif, wo is presenty workin wit Atomic Oranization of Iran (AEOI for is kind tecnica assistance drin preparation of te present work. OMELATUE a cross-section p eat capacity at constant pressre d widt of te cooant canne, diameter d ydraic diameter f friction factor eat transfer coefficient f atent eat of vaporization k terma condctivity eit, axia ent sset nmber 49 Q tota power e eynods nmber t time ΔT temperatre difference between iid pase and as veocity component V veocity vector, vome α void fraction α s soid terma diffsivity β terma expansion coefficient
JOUAL Of ULEA And eated TEHOLOGIES, Vome, o., December 004 Pr Prandt nmber vometric power δ condction tickness ρ density of iid Δρ density difference EFEEES Amad, S. Y., (973, Fid-to-Fid modein of critica eat fx: A compensated distortion mode, Int. J. Heat Mass Transfer, (o.6:64-66. arbiener, A., and dnik,. A., (969, Simiitde consideration for modein ncear reactor bowdowns, Trans. Am. c. Soc., (:36-36. Isii, M., and Kataoka, I., (984, Scain aws for terma-ydraic systems nder sine-pase and two-pase natra circation, c. En. Des., 3(8: 4-45. Kocamstafaoari, G., and Isii, M., (987, Scain of two-pase fow transient sin redced pressre system and simant fid, c. En. Des., 3(04:-3. aavandi, A.., asteana, F. S., and Moradkanian, (979, E.., Scain aws for modein ncear reactor systems, c. Sci. En., (7:75-83. T Amendment to te Safety eport, (989, Version A, IVAP eport Second Edition, Teran. Wite, Frank M., (994, Fid mecanics, 3 rd., McGraw-Hi, ew York. Yadiaro, G., and Zeer, M., (994, Fid-to-Fid scain for a ravity- and fasin-driven natra circation oop, c. En. Des., 5(5:49-64. 50