Kuwonongeka kwa ma valve mu dongosolo ladzidzidzi lamagetsi a nyukiliya la LaSalle

M'chaka chino, NRC Special Inspection Team (SIT) inayendera LaSalle Nuclear Power Plant kuti ifufuze chifukwa cha kulephera kwa valve ndikuwunika momwe njira zowongolera zidatengedwa. Magawo awiri a Exelon Generation Company's LaSalle County Nuclear Power Plant, pafupifupi mailosi 11 kum'mwera chakum'mawa kwa Ottawa, Illinois, ndi ma reactor amadzi otentha (BWR) omwe adayamba kugwira ntchito koyambirira kwa 1980s. Ngakhale ma BWR ambiri omwe akugwira ntchito ku United States ndi BWR/4 yokhala ndi mawonekedwe a Mark I, zida "zatsopano" za LaSalle zimagwiritsa ntchito BWR/5 ndi kapangidwe ka Mark II. Kusiyana kwakukulu pakuwunikaku ndikuti ngakhale BWR/4 imagwiritsa ntchito jekeseni wothamanga kwambiri wothamanga kwambiri (HPCI) kuti apereke madzi oziziritsa owonjezera pachimake ngati chitoliro chaching'ono cholumikizidwa ndi chotengera cha riyakitala chikuphulika, kugwiritsa ntchito BWR/5 Dongosolo loyendetsedwa ndi mota kwambiri (HPCS) limakwaniritsa ntchitoyi. Pa February 11, 2017, pambuyo pokonza ndi kuyesa machitidwe, ogwira ntchito anayesa kudzaza dongosolo la No. 2 high-pressure core spray (HPCS). Panthawiyo, rector ya Unit 2 idatsekedwa chifukwa cha kusokonezeka kwa mafuta, ndipo nthawi yopuma idagwiritsidwa ntchito poyang'ana machitidwe adzidzidzi, monga dongosolo la HPCS. Dongosolo la HPCS nthawi zambiri limakhala loyimirira panthawi yakuchita riyakitala. Dongosololi lili ndi pampu yoyendetsedwa ndi injini yomwe imatha kupereka njira yowonjezera yowonjezera ya magaloni 7,000 pamphindi pachombo cha reactor. Pampu ya HPCS imakoka madzi mu thanki yosungiramo zinthu. Ngati chitoliro chaching'ono cholumikizidwa ndi chotengera cha riyakitala chikusweka, madzi ozizira amatha kutayikira, koma kupanikizika mkati mwa chotengeracho kumayendetsedwa ndi machitidwe angapo otsika kwambiri (ie, kutulutsa zinyalala zotayirira komanso kupopera pang'ono pachimake kutsitsi. ). Madzi otuluka kuchokera kumapeto kwa chitoliro chosweka amatayidwa kupita ku thanki yopondereza kuti agwiritsidwenso ntchito. Pampu ya HPCS yoyendetsedwa ndi injini imatha kuyendetsedwa kuchokera ku gridi yakutali ikapezeka, kapena kuchokera pa jenereta ya dizilo yadzidzidzi yomwe ili pamalopo pomwe gululi silikupezeka. Ogwira ntchito sanathe kudzaza chitoliro pakati pa valavu ya jekeseni ya HPCS (1E22-F004) ndi chotengera cha reactor. Adapeza kuti diskiyo idasiyanitsidwa ndi tsinde la valavu yachipata chapawiri-clapper yopangidwa ndi Anchor Darling, kutsekereza njira yodutsa chitoliro chodzaza. Valavu ya jekeseni ya HPCS ndi valve yamagetsi yotsekedwa yomwe imatsegulidwa pamene dongosolo la HPCS layambika kuti lipereke njira yopangira madzi kuti ifike ku chotengera cha reactor. Galimoto imagwiritsa ntchito torque kutembenuza tsinde la valavu kuti likweze (kutsegula) kapena kutsitsa (kutseka) diski mu valavu. Ikatsitsidwa mokwanira, diskiyo imalepheretsa kuyenda kudzera mu valve. Pamene chotchinga cha valve chikukwezedwa mokwanira, madzi omwe akuyenda mu valve amayenda mosalekeza. Popeza kuti diski imasiyanitsidwa ndi tsinde la valve pamalo otsika kwambiri, galimotoyo imatha kutembenuza tsinde la valve ngati kuti likukweza diski, koma diskiyo sidzasuntha. Ogwira ntchito adatenga zithunzi za ma disks olekanitsidwa awiri atachotsa chivundikiro cha valve (sleeve) ya valve (Chithunzi 3). Mphepete ya pansi pa tsinde ikuwonekera pakatikati pa chithunzicho. Mutha kuwona ma disks awiri ndi njanji zowongolera pawo (pamene zilumikizidwa ndi tsinde la valve). Ogwira ntchitowo adalowa m'malo mwa valavu ya jekeseni ya HPCS ndi zigawo zokonzedwanso ndi wothandizira, ndipo adabwerezanso gawo la No. A Tennessee River Basin Authority adapereka lipoti ku NRC mu Januware 2013 pansi pa 10 CFR Gawo 21 lokhudza zolakwika mu Anchor Darling double disc gate valve mu jekeseni wozizira kwambiri wa Browns Ferry Nuclear Power Plant. Mwezi wotsatira, wothandizira valve adapereka lipoti la 10 CFR Part 21 kwa NRC ponena za mapangidwe a Anchor Darling double disc gate valve, zomwe zingapangitse kuti tsinde la valve lilekanitse ndi disc. Mu April 2013, Boiling Water Reactor Owners Group inapereka lipoti la Part 21 lipoti kwa mamembala ake ndi njira zowonetsera momwe ma valve okhudzidwa akuyendera. Malangizowo akuphatikizapo kuyezetsa matenda ndikuwunika kuzungulira kwa tsinde. Mu 2015, ogwira ntchito adayesa mayeso ovomerezeka a HPCS jekeseni valavu 2E22-F004 ku LaSalle, koma palibe mavuto omwe adapezeka. Pa February 8, 2017, ogwira ntchito adagwiritsa ntchito ndondomeko yowunikira kuzungulira kwa tsinde kuti asunge ndi kuyesa valavu ya jakisoni ya HPCS 2E22-F004. Mu Epulo 2016, gulu la eni ake opangira madzi otentha adakonzanso lipoti lawo potengera zomwe mwiniwake wamagetsi adapereka. Ogwira ntchito adasokoneza ma valve a 26 Anchor Darling awiri omwe angakhale ovuta ndipo anapeza kuti 24 mwa iwo anali ndi mavuto. Mu April 2017, Exelon adadziwitsa NRC kuti valavu ya jekeseni ya HPCS 2E22-F004 inalephera chifukwa cha kupatukana kwa tsinde la valve ndi disc. Pasanathe milungu iwiri, gulu lapadera loyang'anira (SIT) lolembedwa ndi NRC linafika ku LaSalle kuti lifufuze chifukwa cha kulephera kwa valve ndikuwunika momwe njira zowonetsera zimagwirira ntchito. SIT adawunikiranso kuwunika kwa Exelon za kulephera kwa valavu ya jakisoni ya Unit 2 HPCS. SIT inavomereza kuti chigawo china mkati mwa valve chinaphulika chifukwa cha mphamvu zambiri. Gawo losweka limapangitsa kuti mgwirizano pakati pa tsinde la valve ndi intervertebral disc ukhale wocheperako, mpaka intervertebral disc potsiriza imalekanitsa ndi tsinde la valve. Woperekayo adakonzanso mawonekedwe amkati a valve kuti athetse vutoli. Exelon adadziwitsa NRC pa June 2, 2017 kuti ikukonzekera kukonza ma valve ena a 16 okhudzana ndi chitetezo ndi chitetezo chofunika kwambiri cha Anchor Darling, chomwe chingakhale chowopsa kwa izi panthawi ya kusokonezeka kwa mafuta kwa zigawo ziwiri za LaSalle. Zotsatira za makina olephera. SIT idawunikiranso zifukwa za Exelon zodikirira kukonza ma valve 16 awa. SIT amakhulupirira kuti chifukwa chake ndi chomveka, kupatulapo chimodzi-valavu ya jekeseni ya HCPS pa Unit 1. Exelon anayerekezera chiwerengero cha ma valve a jekeseni a HPCS a Unit 1 ndi Unit 2. Valavu ya Unit 2 inali zipangizo zoyambirira zomwe zinayikidwa kumayambiriro kwa zaka za m'ma 1980. , pamene valve ya Unit 1 inasinthidwa mu 1987 itatha kuwonongeka pazifukwa zina. Exelon adanena kuti kuchuluka kwa zikwapu za valve ya Unit 2 kunafotokozera kulephera kwake, ndipo panali chifukwa chodikirira mpaka kusokonezeka kwa mafuta owonjezera kuti athetse vuto la valavu ya Unit 1. SIT inatchula zinthu monga kusiyana kosadziwika kwa mayeso asanayambe ntchito. mayunitsi, kusiyana pang'ono kapangidwe ndi zotsatira zosadziwika, kusatsimikizika kwamphamvu zakuthupi, komanso kusiyana kosatsimikizika kwa ma valve oyambira mpaka kuvala kwa ulusi, ndipo adatsimikiza kuti "izi ndizomwe" Vuto la Nthawi" m'malo mwa "Ngati" 1E22-F004 Vavu idzalephera. ngati palibe kulephera m'tsogolomu, SIT sinagule kuchedwa kwa valavu ya Unit 1 ya LaSalle Unit 1 pa June 22, 2017 kuti ilowe m'malo mwa valavu ya HPCS 1E22-F004 adapeza kuti ma torque opangidwa ndi Exelon a mavavu a jakisoni a HPCS 1E22-F004 ndi 2E22-F004 amaphwanya 10 CFR Gawo 50, Zowonjezera B, Standard III, Kuwongolera kwa Exelon kumaganiza kuti tsinde la valavu ndi ulalo wofooka imakhazikitsa mtengo wamakokedwe a mota omwe sakukakamiza kwambiri patsinde la valve. Koma ulalo wofookawo unakhala gawo lina lamkati. Mtengo wa torque wa injini womwe ukugwiritsidwa ntchito ndi Exelon umapangitsa gawolo kukhala lopanikizika kwambiri, kupangitsa kuti lisweka ndipo diskiyo isiyanitsidwe ndi tsinde la valve. NRC inatsimikiza kuti kuphwanyako kunali kuphwanya kwakukulu kwa III malinga ndi kulephera kwa valve komwe kunalepheretsa dongosolo la HPCS kuchita ntchito zake zachitetezo (mu dongosolo la magawo anayi, mlingo I ndi wovuta kwambiri). Komabe, NRC idagwiritsa ntchito nzeru zake potsatira malamulo ake ndipo sinafalitse zophwanya malamulo. NRC idatsimikiza kuti cholakwika cha valavu chinali chobisika kwambiri kuti Exelon adziwoneratu ndikuwongolera valavu ya Unit 2 isanathe. Exelon adawoneka bwino pamwambowu. Zolemba za SIT za NRC zimasonyeza kuti Exelon akudziwa za Part 21 lipoti lopangidwa ndi Tennessee River Basin Authority ndi wopereka ma valve ku 2013. Sanathe kugwiritsa ntchito chidziwitso ichi kuti azindikire ndi kukonza vuto la valve jekeseni ya Unit 2 HPCS. Izi kwenikweni sizikuwonetsa kusachita bwino kwawo. Kupatula apo, adagwiritsa ntchito zomwe a Boiling Water Reactor Owner's Gulu la eni ake amalipoti awiri a Gawo 21. Choyipa chagona mu kalozera, osati kagwiritsidwe ntchito ka Exelon. Cholakwika chokhacho chomwe Exelon amachitira nkhaniyi chinali chakuti chifukwa chogwiritsira ntchito Unit 1 chinali chofooka musanayang'ane ngati valavu yake ya jekeseni ya HPCS inawonongeka kapena kuonongeka, mpaka kukonzanso kwake kotsatira kunasokonezedwa. Komabe, SIT ya NRC idathandizira Exelon kusankha kufulumizitsa dongosololi. Zotsatira zake, Unit 1 idatsekedwa mu June 2017 kuti ilowe m'malo mwa valavu ya Unit 1. NRC idawoneka bwino kwambiri pamwambowu. Sikuti NRC inangotsogolera Exelon kumalo otetezeka a LaSalle Unit 1, koma NRC inalimbikitsanso makampani onse kuti athetse vutoli popanda kuchedwa. NRC inapereka chidziwitso cha 2017-03 kwa eni fakitale pa June 15, 2017, ponena za zolakwika za kamangidwe ka Anchor Darling double disc gate valve ndi malire a malangizo owunikira machitidwe a valve. NRC idachita misonkhano yambiri yapagulu ndi oyimilira ogulitsa ndi ma valve pavutoli ndi mayankho ake. Chimodzi mwazotsatira za kuyanjana kumeneku ndikuti makampaniwa adalembapo masitepe angapo, dongosolo lokhazikika lomwe lili ndi nthawi yomaliza yomwe chandamale pasanafike pa Disembala 31, 2017, komanso kafukufuku wokhudza kugwiritsa ntchito ma valve a Anchor Darling double disc gate mu mphamvu zanyukiliya zaku US. zomera. Kafukufuku akuwonetsa kuti pafupifupi 700 Anchor Darling double disc gate valves (AD DDGV) amagwiritsidwa ntchito m'mafakitale a nyukiliya ku United States, koma ma valve 9 okha ali ndi zizindikiro za chiopsezo chachikulu / chapakati, ma valve ambiri a stroke. (Ma valve ambiri amakhala ndi sitiroko imodzi, chifukwa ntchito yawo yachitetezo ndikutseka ikatsegulidwa, kapena kutseguka ikatsekedwa. Ma valve ambiri amatha kutchedwa otsegula ndi otseka, ndipo akhoza kutsegulidwa ndi kutsekedwa kangapo kuti akwaniritse ntchito yawo yachitetezo.) makampani akadali ndi nthawi yoti abwezeretsenso kulephera kwawo pakupambana, koma NRC ikuwoneka yokonzeka kuwona zotsatira zanthawi yake komanso zogwira mtima pankhaniyi. Tumizani SMS "SCIENCE" ku 662266 kapena lembani pa intaneti. Lembani kapena tumizani SMS "SCIENCE" ku 662266. Malipiro a SMS ndi deta akhoza kulipiritsidwa. Mawuwa asiya kutuluka. Palibe chifukwa chogula. Migwirizano ndi zokwaniritsa. © Union of Concerned Scientists Ndife bungwe la 501(c)(3) lopanda phindu. 2 Brattle Square, Cambridge MA 02138, USA (617) 547-5552