Iivalvu ezonakeleyo kwinkqubo yonxunguphalo yeplanti yamandla enyukliya yaseLaSalle

Ngentwasahlobo, iQela loHlolo oluKhethekileyo lwe-NRC (SIT) liqhube uhlolo lweSiziko saMandla seNyukliya saseLaSalle ukuphanda unobangela wokusilela kwevalvu nokuvavanya ukusebenza kwamanyathelo okulungisa athathiweyo. Iiyunithi ezimbini ze-Exelon Generation Company's LaSalle County Nuclear Power Plant, malunga neekhilomitha ezili-11 kumzantsi-mpuma we-Ottawa, e-Illinois, zizixhobo zamanzi abilayo (BWR) ezaqala ukusebenza ekuqaleni koo-1980. Nangona uninzi lwee-BWR ezisebenza eUnited States ziyi-BWR/4 kunye noyilo lwesiqulatho sikaMark I, izixhobo "ezintsha" zeLaSalle zisebenzisa i-BWR/5 kunye noyilo lwesiqulatho sikaMark II. Umahluko omkhulu kolu hlaziyo kukuba nangona i-BWR/4 isebenzisa isitofu esiqhutywa ngumphunga (HPCI) ukubonelela ngamanzi okupholisa okongeziweyo kwi-reactor core xa umbhobho omncinci odibanisa umkhumbi we-reactor uqhekeza, i-BWR / 5 isebenzisa inkqubo ye-motor-driven High Pressure Core Spray (HPCS) ukuphumeza le ndima yokhuseleko. NgoFebruwari 11, 2017, emva kokugcinwa kwenkqubo kunye novavanyo, abasebenzi bazama ukuphinda bazalise inkqubo ye-2 high-pressure core injection (HPCS). Ngelo xesha, i-reactor ye-Unit 2 ivaliwe ngenxa yokuphazamiseka kwe-refueling, kwaye ixesha lokunciphisa lalisetyenziselwa ukujonga iinkqubo eziphuthumayo, ezifana nenkqubo ye-HPCS. Inkqubo ye-HPCS idla ngokuba kwimo yokulinda ngexesha lokusebenza kwereactor. Inkqubo ixhotyiswe ngempompo eqhutywa yimoto enokubonelela ngokuyilwa kokuhamba okongeziweyo kwe-7,000 iilitha ngomzuzu kwinqanawa ye-reactor. Impompo ye-HPCS itsala amanzi kwitanki yesithintelo kwisiqulatho. Ukuba umbhobho omncinci wediameter odityaniswe kwinqanawa yereactor uyaphuka, amanzi okupholisa aya kuvuza, kodwa uxinzelelo olungaphakathi kwinqanawa yereactor lusebenza ngothotho lweenkqubo ezingxamisekileyo zoxinzelelo oluphantsi (oko kukuthi, ukukhutshwa kobushushu obuphantsi kunye nempompo yokutshiza esezantsi yoxinzelelo oluphantsi. ). Amanzi aqukuqelayo aphuma kumbhobho oqhekekileyo ekupheleni ayakhutshelwa kwitanki yocinezelo ukuze aphinde asetyenziswe. Ipompo ye-HPCS eqhutywa ngemoto inokunikwa amandla ukusuka kwigridi ye-off-site xa ikhona, okanye kwi-site ye-diesel generator engxamisekileyo xa igridi ingafumaneki. Abasebenzi abakwazanga ukuzalisa umbhobho phakathi kwe-HPCS injection valve (1E22-F004) kunye nomkhumbi we-reactor. Baye bafumanisa ukuba i-disc ihlukaniswe kwi-stem ye-valve ye-double-clapper gate eyenziwe ngu-Anchor Darling, evimba indlela yokuhamba kombhobho wokuzalisa. Ivalve yokutofa yeHPCS yivalve yombane eqhele ukuvaleka evula xa inkqubo yeHPCS iqalwa ukuze ibonelele ngomjelo wamanzi okwenza ukuba afikelele kwinqanawa yereactor. I-motor isebenzisa i-torque ukujikelezisa isiqu sevalve ejikelezayo ukunyusa (ukuvula) okanye ukwehlisa (ukuvala) idiski kwivalve. Xa ithotywe ngokupheleleyo, idiski iya kuvala ukuhamba ngevalve. Xa i-valve flap inyuswe ngokupheleleyo, amanzi aqukuqela kwivalve ahamba engathinteleki. Ekubeni i-disc ihlukaniswe kwi-valve stem kwindawo ephantsi ngokupheleleyo, i-motor inokujikeleza i-valve stem njengokungathi iphakamisa i-disc, kodwa i-disc ayiyi kuhamba. Abasebenzi bathatha imifanekiso yeediski ezimbini ezihlukeneyo emva kokususa i-valve cover (umkhono) wevalve (Umfanekiso 3). Isiphelo esisezantsi sesiqu sibonakala kumbindi ongentla womfanekiso. Uyakwazi ukubona iidiski ezimbini kunye neentsimbi zesikhokelo ecaleni kwazo (xa uqhagamshelwe kwisikhondo sevalve). Abasebenzi batshintshe iindawo zangaphakathi ze-HPCS i-injection valve kunye neenxalenye eziphinde zayilwa ngumthengisi, kwaye baphinda baphinda iyunithi ye-2. I-Tennessee River Basin Authority ingenise ingxelo kwi-NRC ngo-Januwari ka-2013 phantsi kwe-10 CFR iSigaba sama-21 malunga neziphene kwi-Anchor Darling idiskhi ephindwe kabini iveluvu yesango kwisixokelelwano soxinzelelo oluphezulu sokupholisa se-Browns Ferry Nuclear Power Plant. Ngenyanga elandelayo, umthengisi wevalve ungenise ingxelo ye-10 CFR Icandelo le-21 kwi-NRC malunga nengxaki yoyilo lwe-Anchor Darling i-valve ye-disc ye-disc ye-disc, enokubangela ukuba i-valve stem ihluke kwi-disc. Ngo-Epreli wama-2013, iQela labanini beReactor yaManzi abilayo likhuphe ingxelo ngeNxalenye yama-21 ingxelo kumalungu alo kunye neendlela ezicetyiswayo zokuhlola ukusebenza kweevalvu ezichaphazelekayo. Iingcebiso ziquka iimvavanyo zokuxilonga kunye nokubeka iliso ukujikeleza kwesiqu. Kwi-2015, abasebenzi benza iimvavanyo zokuxilonga ezicetyiswayo kwi-HPCS injection valve 2E22-F004 eLaSalle, kodwa akukho zingxaki zokusebenza ezifunyenweyo. Ngomhla we-8 kaFebruwari, i-2017, abasebenzi basebenzisa i-stem rotation monitoring guide ukugcina nokuvavanya i-HPCS injection valve 2E22-F004. Ngo-Epreli ka-2016, iqela labanini be-reactor yamanzi abilayo lihlaziye ingxelo yabo ngokusekelwe kulwazi olunikezelwe ngumninimzi-mveliso wamandla. Abasebenzi baqhawula i-26 Anchor Darling iivalvu zesango eziphindwe kabini ezinokuthi zibe sengozini kwaye bafumanisa ukuba i-24 yabo ineengxaki. Ngo-Ephreli 2017, i-Exelon yazisa i-NRC ukuba i-HPCS injection valve 2E22-F004 ayiphumelelanga ngenxa yokuhlukana kwe-valve stem kunye ne-disc. Kwiiveki ezimbini, iqela lokuhlola elikhethekileyo (SIT) eligunyaziswe yi-NRC lafika eLaSalle ukuphanda imbangela yokungaphumeleli kwe-valve kunye nokuvavanya ukuphumelela kwamanyathelo okulungisa athathiweyo. I-SIT iphonononge uvavanyo lwe-Exelon lwemowudi yokusilela kweYunithi 2 yevalve yokutofa yeHPCS. I-SIT ivumile ukuba inxalenye engaphakathi kwesivalo yagqabhuka ngenxa yamandla agqithisileyo. Inxalenye ephukileyo ibangela uxhulumaniso phakathi kwe-valve stem kunye ne-disc intervertebral ukuba iqhube ngokungahambi kakuhle, de kube i-disc intervertebral ekugqibeleni ihluke kwi-valve stem. Umthengisi uphinde waqulunqa isakhiwo sangaphakathi sevalve ukusombulula ingxaki. I-Exelon yazisa i-NRC ngoJuni 2, i-2017 ukuba iceba ukulungisa ezinye ii-16 ezinxulumene nokhuseleko kunye nokhuseleko olubalulekileyo lwe-Anchor Darling i-valve ye-disc ye-disc ephindwe kabini enokuthi ibe sengozini kule ntsilelo ngexesha lokuphazamiseka okulandelayo kwe-refueling yeeyunithi ezimbini ze-LaSalle Impembelelo isixhobo. I-SIT iphonononge izizathu ze-Exelon zokulinda ukulungisa ezi zivalo zili-16. I-SIT ikholelwa ukuba isizathu sifanelekile, ngaphandle kwesinye-ivalve yokutofa yeHCPS kwiYunithi 1. I-Exelon yaqikelela inani lemijikelo yevalvu yokutofa yeHPCS yeYunithi 1 kunye neYunithi 2. Ivalve yeYunithi 2 yayisisixhobo sokuqala esafakelwa ekuqaleni. 1980s, ngelixa i-valve yeYunithi 1 yatshintshwa ngo-1987 emva kokuba yonakaliswe ngenxa yezinye izizathu. U-Exelon uthe inani elikhulu le-valve strokes kwiyunithi ye-2 ichaze ukungaphumeleli kwayo kwaye kukho isizathu sokulinda de uphazamiseko olulandelayo lwe-refueling ukusombulula ingxaki ye-valve yeyunithi ye-1. I-SIT ikhankanya izinto ezifana ne-pre-operation engaziwa umahluko phakathi kweeyunithi, kancinci. Ulwahlulo loyilo oluneziphumo ezingaziwayo, iimpawu zamandla ezinto ezingaqinisekanga, kunye nokwahluka okungaqinisekanga kwisiqu sevalve ukuya kumsonto wokunxitywa kwentambo, kwaye wagqiba ngelithi "le" yingxaki yexesha" endaweni ye "Ukuba" 1E22-F004 Ivalve iya kusilela ukuba kukho. Akukho kusilela kwixesha elizayo, i-SIT ayizange ithenge ukulibaziseka kwe-valve ye-Exelon ye-1 ye-LaSalle ngo-Juni 22, i-2017 ukuze ithathe indawo ye-HPCS i-injection valve 1E22-F004 Amaxabiso e-torque aphuhliswe yi-Exelon yee-motor ze-HPCS iivalvu inaliti 1E22-F004 kunye ne-2E22-F004 yaphulwa 10 CFR Icandelo 50, iSihlomelo B, i-Standard III, i-Exelon yoYilo ithatha ukuba isiqu sevalve yikhonkco ebuthathaka, kwaye iseka a ixabiso letorque yemoto engasithobeliyo isikhondo sevalve kuxinzelelo olugqithisileyo. Kodwa ikhonkco ebuthathaka yajika yaba yenye inxalenye yangaphakathi. Ixabiso le-torque ye-motor esetyenziswe yi-Exelon ibeka inxalenye phantsi koxinzelelo olugqithisileyo, ibangela ukuba iphuke kwaye i-disc ihlukane ne-valve stem. I-NRC inqume ukuphulwa njengolwaphulo olunzima lwe-III olusekelwe kwi-valve engaphumeleliyo eyathintela inkqubo ye-HPCS ekwenzeni imisebenzi yayo yokhuseleko (kwinkqubo yenqanaba ezine, inqanaba I linzima kakhulu). Nangona kunjalo, i-NRC isebenzise ukuqonda kwayo kokuthotyelwa komthetho ngokuhambelana nomgaqo-nkqubo wayo wokuthotyelwa komthetho kwaye ayizange ipapashe ukuphulwa. I-NRC igqibe ekubeni isiphene soyilo lwevalvu sichubekile kakhulu ukuba i-Exelon ibone kwangaphambili kwaye ilungise phambi kokusilela kwevalvu yeYunithi 2. U-Exelon wayekhangeleka emhle kakhulu kulo msitho. Iirekhodi ze-SIT ze-NRC zibonisa ukuba i-Exelon iyayazi ingxelo yeNxalenye ye-21 eyenziwe nguGunyaziwe we-Tennessee Valley kunye nomthengisi wevalvu ngo-2013. Abakwazanga ukusebenzisa olu lwazi ukuchonga nokulungisa iingxaki zevalvu yesitofu se-Unit 2 yeHPCS njengembonakalo yokusebenza kwabo kakubi. . Ngapha koko, baphumeze imilinganiselo ecetyisiweyo liQela labaMnini beReactor yaManzi aBilayo kwiingxelo ezimbini zeCandelo lama-21. Ukusilela kukwisikhokelo, hayi indlela i-Exelon esisebenzisa ngayo. Ekuphela kwesiphene kwindlela i-Exelon ewusingatha ngayo lo mba yayikukuba isizathu sokusebenzisa iYunithi yoku-1 yayibuthathaka phambi kokuba kujongwe ukuba ivalve yayo yokutofa yeHPCS yonakele okanye yonakele, de kwaphazamiseka ukufakwa kwayo kwepetroli okucwangcisiweyo okulandelayo. Nangona kunjalo, i-SIT ye-NRC yanceda u-Exelon ukuba enze isigqibo sokukhawulezisa isicwangciso. Ngenxa yoko, iYunithi yoku-1 yavalwa ngoJuni 2017 ukuze ithathe indawo yesivalo seYunithi yoku-1 esengozini. I-NRC ibonakala ilungile kakhulu kwesi siganeko. Akukhona nje ukuba i-NRC iholele i-Exelon kwindawo ekhuselekileyo ye-LaSalle Unit 1, kodwa i-NRC nayo yakhuthaza yonke imboni ukuba ixazulule le ngxaki ngaphandle kokulibaziseka okungenangqiqo. I-NRC ikhuphe isaziso solwazi lwe-2017-03 kubanikazi befektri ngoJuni 15, i-2017, malunga neziphene zokuyila ze-Anchor Darling i-valve ye-disc ye-disc ye-double disc kunye nokunciphisa izikhokelo zokubeka iliso kwi-valve. I-NRC ibambe uthotho lweentlanganiso zikawonke-wonke kunye nabameli beshishini kunye nabanikezeli bevalvu ngengxaki kunye nezisombululo zayo. Esinye seziphumo zolu nxibelelwano kukuba ishishini lidwelise uthotho lwamanyathelo, isicwangciso sokuzinzisa esinomhla wokugqibela ekujoliswe kuwo ungadlulanga umhla wama-31 kuDisemba, 2017, kunye nophando malunga nokusetyenziswa kwe-Anchor Darling iivalve zediskhi eziphindwe kabini kumandla enyukliya ase-US. izityalo. Uphando lubonisa ukuba malunga ne-700 Anchor Darling i-double disc gate valves (AD DDGV) isetyenziswa kwimizi-mveliso yamandla enyukliya e-United States, kodwa ziivalvu ezili-9 kuphela ezineempawu zomngcipheko ophezulu/ophakathi, we-multi-stroke valves. (Iivalve ezininzi zi-single-stroke, kuba umsebenzi wazo wokhuseleko kukuvala xa zivulwa, okanye zivuleke xa zivaliwe. Iivalve ze-Multi-stroke zingabizwa ngokuba zivulekile kwaye zivaliwe, kwaye zinokuvulwa kwaye zivalwe amaxesha amaninzi ukuphumeza umsebenzi wazo wokhuseleko.) imboni isenalo ixesha lokubuyisela ukungaphumeleli kwayo ekuphumeleleni, kodwa i-NRC ibonakala ikulungele ukubona iziphumo ezifike ngexesha kunye nezisebenzayo kulo mbandela. Thumela i-SMS ethi "SCIENCE" ku-662266 okanye ubhalise kwi-intanethi. Bhalisa okanye uthumele i-SMS ethi "SAYENSI" ku-662266. Iintlawulo ze-SMS kunye nedatha zinokubizwa. Okubhaliweyo kuyeka ukuphuma. Akukho mfuneko yokuthenga. Imimmiselo nemiqathango. © IManyano yeeNzululwazi eziZixhalabileyo Singumbutho wama-501(c)(3) ongenzi nzuzo. 2 Brattle Square, Cambridge MA 02138, USA (617) 547-5552