Bincike game da bala'in Chernobyl

 

Bala'i na Chernobyl wani bala'i ne na nukiliya wanda ya faru a farkon sa'o'i na 26 Afrilu 1986, a tashar wutar lantarki ta Chernobyl a Tarayyar Soviet. Hatsarin ya faru ne a lokacin da Reactor Number 4 ya fashe tare da lalata mafi yawan ginin reactor, inda ya yada tarkace da kayan aikin rediyo a duk fadin yankin, kuma a cikin kwanaki da makonni masu zuwa, galibin kasashen Turai sun gurbata da radionuclides wadanda ke fitar da hadarin gaske na ionizing radiation. Don bincika musabbabin hatsarin, Hukumar Kula da Makamashin Nukiliya ta Duniya (IAEA) ta yi amfani da kungiyarta, Kungiyar Ba da Shawarar Kare Nukiliya ta Duniya (INSAG).

Bincike

Hukumar IAEA ta fitar da muhimman rahotanni guda biyu kan Chernobyl; INSAG-1 a shekarar 1986, da kuma rahoton da aka yi wa kwaskwarima, INSAG-7 a shekarar 1992. A takaice dai, a cewar INSAG-1, babban abin da ya haddasa hatsarin shi ne ayyukan da ma’aikatan suka yi, amma a cewar INSAG-7, babban abin da ya jawo shi ne na’urar sarrafa wutar lantarki. : 24 Dukkan rahotannin IAEA sun gano rashin isassun "al'adar aminci" (INSAG-1 ta ƙirƙira kalmar) a duk matakan gudanarwa da aiki a matsayin babban abin da ke haifar da ɓangarori daban-daban na haɗarin. An bayyana wannan ba kawai a cikin ayyuka ba har ma a lokacin ƙira, injiniyanci, gini, ƙira da tsari. : 21, 24 

Ƙungiyoyi daban-daban sun nuna sha'awar ra'ayoyin manyan abubuwan da suka faru, ciki har da masu zanen reactor, ma'aikatan wutar lantarki, da gwamnatocin Soviet da Ukrainian. Wannan ya faru ne saboda rashin tabbas game da ainihin jerin abubuwan da suka faru da kuma sigogi na shuka. Bayan INSAG-1, ƙarin bayani ya sami samuwa kuma akwai ƙarin ƙididdigewa mai ƙarfi don kwaikwaiyo. : 10 

Ƙarshen INSAG-7 na manyan abubuwan da suka ba da gudummawa ga hadarin shine:

A yanzu ana ganin Hatsarin ya kasance sakamakon haduwar manyan abubuwa masu zuwa: takamaiman halaye na jiki na reactor; ƙayyadaddun ƙirar ƙira na abubuwan sarrafa reactor; da kuma gaskiyar cewa an kawo reactor zuwa jihar da ba a kayyade ta hanyar hanyoyin ba ko kuma ta bincikar ta wata ƙungiyar tsaro mai zaman kanta. Mafi mahimmanci, halayen jiki na reactor sun sa ya yiwu halinsa mara kyau.

Rahoton INSAG-1 (1986)

Masana kimiyya da injiniyoyi na Soviet sun ba da bayanin farko na hadarin ga wakilan kasashe membobin IAEA da sauran kungiyoyin kasa da kasa a taron farko na bayan hadarin, wanda aka gudanar a IAEA a Vienna, 25-29 Agusta 1986. Wannan bayanin ya sanya zargi a kan masu aiki da wutar lantarki. Rahoton IAEA INSAG-1 ya biyo baya ba da daɗewa ba a watan Satumbar 1986, kuma gabaɗaya ya goyi bayan wannan ra'ayi, bisa ga bayanan da aka bayar a tattaunawar tare da masana Soviet a taron bita na Vienna. A cikin wannan ra'ayi, hatsarin bala'i ya haifar da manyan keta ka'idojin aiki da ka'idoji. Misali; "A lokacin shirye-shirye da gwaji na janareta na turbine a ƙarƙashin yanayin lalacewa ta amfani da nauyin taimako, ma'aikata sun katse jerin tsarin kariya na fasaha kuma sun karya mahimman tanadin tsaro na aiki don gudanar da aikin fasaha. " :

An bayyana cewa a lokacin hadarin ana sarrafa reactor tare da maɓallin tsaro da yawa, mafi mahimmanci tsarin sanyaya na gaggawa (ECCS), LAR (Local Automatic control system), da AZ (emergency power reduction system). Ma'aikata ba su da isasshen fahimta game da hanyoyin fasaha da ke tattare da na'urar nukiliya, kuma da gangan sun yi watsi da ka'idoji don hanzarta kammala gwajin lantarki. Yawancin rashin daidaito na tsari sun taimaka wajen yin hadarin ya yiwu, daya daga cikinsu bai isa ba sadarwa tsakanin jami'an tsaro da masu gudanar da gwajin.

An yi imanin cewa masu zane-zane na reactor sun yi la'akari da wannan haɗuwa da abubuwan da ba za a iya yiwuwa ba don haka ba su ba da izinin ƙirƙirar tsarin kariya na gaggawa ba wanda zai iya hana haɗuwa da abubuwan da suka haifar da rikicin, wato nakasar da gangan na kayan kariya na gaggawa tare da keta hanyoyin aiki. Don haka babban abin da ya haifar da hatsarin shi ne haɗuwa da keta doka da ba za a iya yiwuwa ba tare da tsarin aiki da ma'aikatan tashar wutar lantarki suka ba da izini. : 312 

A kan katsewar tsarin tsaro, Valery Legasov ya ce a cikin 1987, "Yana kama da matukan jirgin sama suna gwaji tare da injuna a cikin jirgin. " A cikin wannan bincike, an zargi ma'aikatan, amma an keɓe rashi a cikin ƙirar reactor da kuma a cikin ƙa'idodin aiki wanda ya sa hatsarin ya yiwu kuma an ambaci su kawai a hankali. Wannan ra'ayi ya bayyana a cikin wallafe-wallafe da yawa da ayyukan fasaha a kan jigon hadarin Chernobyl wanda ya bayyana nan da nan bayan hadarin, kuma ya kasance mai rinjaye a cikin fahimtar jama'a da kuma a cikin shahararrun wallafe-wallafe na dogon lokaci.

Shari'ar aikata laifuka ta Soviet (1987)

An gudanar da shari'ar ne daga 7 zuwa 30 ga Yuli 1987 a cikin kotun wucin gadi da aka kafa a cikin House of Culture a birnin Chernobyl, Ukraine. Ma'aikata biyar na masana'anta (Anatoly S. Dyatlov, tsohon mataimakin babban injiniya; Viktor P. Bryukhanov, tsohon darektan masana'anta; Nikolai M. Fomin, tsohon babban injiniya); Boris V. Rogozhin, darektan sauyawa na Reactor 4; da Aleksandr P. Kovalenko, shugaban Reactor 4); da Yuri A. Laushkin (Gosatomenergonadzor [USSR State Committee on Supervision of Safe Conduct of Work in Atomic Energy) an yanke musu hukuncin shekaru goma, a cikin sansanoni goma, goma, da biyar bi da bi da bi Iyalan Aleksandr Akimov, Leonid Toptunov da Valery Perevozchenko sun sami wasiƙu na hukuma, amma an dakatar da tuhumar ma'aikatan a mutuwarsu.

An sami Anatoly Dyatlov da laifi "na rashin kula da aikata laifuka na kamfanoni masu fashewa" kuma an yanke masa hukuncin shekaru goma a kurkuku - wanda zai yi aiki uku - saboda rawar da ya kula da gwajin ya taka a hadarin da ya biyo baya.

Rahoton INSAG-7 (1992)

Gidan reactor na 1 na Chernobyl Plant

Hoton da aka sauƙaƙe wanda ya kwatanta Chernobyl RBMK da ƙirar nukiliya mafi yawanci, mai sarrafa ruwa mai haske. Batutuwan RBMK: 1. Yin amfani da mai daidaitawa na graphite a cikin reactor mai sanyaya ruwa, yana ba da izini a cikin asarar hadarin sanyaya. 2. Kyakkyawan ƙarancin tururi wanda ya sa ya yiwu a yi amfani da ikon lalacewa. 3. Tsarin sandunan sarrafawa; ɗaukar sakan 18-20 don a saka shi gaba ɗaya, kuma tare da shawarwari na graphite waɗanda suka ƙara amsawa da farko. 4. Babu wani gini mai ƙarfi.

A cikin 1991, Kwamitin Gwamnatin USSR don Kula da Tsaro a Masana'antu da Nukiliya ya sake nazarin abubuwan da suka haifar da hadarin Chernobyl kuma ya zo ga sabon fahimta da yanke shawara. Dangane da wannan, INSAG ta buga wani ƙarin rahoto, INSA G-7, wanda ya sake nazarin "wannan ɓangaren rahoton INSAG-1 wanda aka ba da kulawa ta farko ga dalilan hatsarin, " kuma wannan ya haɗa da rubutun rahoton Hukumar Gwamnatin USSR ta 1991 wanda IAEA ta fassara zuwa Turanci a matsayin Ƙaddamarwa I.

Ya zuwa lokacin wannan rahoton, gwamnatin Ukrain bayan Tarayyar Soviet ta fitar da wasu takardun KGB daga lokacin tsakanin 1971 da 1988 da ke da alaƙa da shukar Chernobyl. Ya ambaci, alal misali, rahotannin da suka gabata na lalacewar tsarin da aka yi ta hanyar sakaci yayin gina masana'antar (kamar tsagewar siminti) waɗanda ba a taɓa yin aiki da su ba. Sun rubuta fiye da yanayin gaggawa 29 a cikin shuka a cikin wannan lokacin, takwas daga cikinsu sun faru ne sakamakon sakaci ko rashin iyawa daga ɓangaren mutum.

A cikin rahoton INSAG-7, yawancin zarge-zargen da aka yi wa ma'aikata a baya don keta ka'idoji an yarda da su ko dai kuskure ne, bisa ga bayanan da ba daidai ba da aka samu a cikin watan Agusta 1986, ko kuma an yanke hukuncin rashin dacewa. Rahoton na INSAG-7 kuma ya nuna ra'ayi na asusun Hukumar Jihar USSR na 1991 wanda ya gudanar da cewa ayyukan masu aiki a cikin kashe tsarin kwantar da hankali na gaggawa, da tsoma baki tare da saitunan akan kayan kariya, da kuma toshe matakin da matsa lamba a cikin ganga mai raba ba su taimaka ga ainihin dalilin hadarin da girmansa ba, ko da yake sun kasance sun saba wa ka'idoji. A gaskiya ma, kashe tsarin gaggawa da aka tsara don hana masu samar da injin turbine guda biyu tsayawa ba cin zarafi ba ne. Hukumomin Soviet sun gano ayyukan ma'aikata da yawa a matsayin keta ka'idoji a cikin rahoton asali na 1986; babu irin waɗannan ka'idojin da ke wurin. : 18 

Babban ƙirar da ta haifar da hadarin, kamar yadda INSAG-7 ta ƙayyade, babban rashi ne a cikin fasalulluka na aminci, : 22 musamman tasirin "ƙayyadaddun ƙira" wanda ya haifar da shawarwarin graphite na sandunan sarrafawa waɗanda da farko suka kara saurin amsawa lokacin da sandunan sarrafa suka shiga cikin core don ƙoƙarin rage amsawa. : 16 Har ila yau, akwai ma'auni mai kyau na reactor, inda tururi da aka samar a cikin tashoshin sanyaya mai zai kara karfin gwiwa saboda an rage sinadarin neutron, wanda ya haifar da ƙarin tururi, kuma ta haka ne ƙarin komai; tsarin sake farfadowa. : 13 

Masu aiki ba su da darajar gefen aiki na reactor (ORM); : 17 ba su da masaniya game da muhimmancin aminci na ORM akan komai da ƙarfin wutar lantarki. : 14 Koyaya, ka'idoji sun haramta yin aiki da reactor tare da karamin bangare na amsawa. Duk da haka "bincike bayan hatsari ya nuna cewa hanyar da ainihin rawar da ORM ke takawa a cikin Ayyukan Ayyuka da takardun ƙira don RBMK-1000 yana da saɓani sosai", kuma ƙari, "Ba a bi da ORM a matsayin iyakar tsaro na aiki ba, wanda keta shi na iya haifar da haɗari".[a] : 34–25 

Ko da a cikin wannan bita, an gano dalilin ɗan adam a matsayin babban abin da ya haifar da hadarin, musamman karkatar da ma'aikatan aiki daga shirin gwajin; "an yi canje-canje marasa amincewa a cikin hanyar gwajin da gangan, kodayake an san shuka tana cikin yanayi daban-daban daga wanda aka nufa don gwajin. " : 24 Wannan ya haɗa da aiki da reactor a matakin ƙaramin wutar lantarki fiye da wanda aka tsara 700 MW kafin fara gwajin lantarki. Duk da ikirarin 1986 na masana Soviet duk da haka, ka'idoji ba su hana aiki da reactor a wannan matakin ƙaramin iko ba.  

INSAG-7 ya kuma ce, "Rashin ingancin hanyoyin aiki da umarnin, da halayensu masu rikice-rikice, sun sanya nauyi mai nauyi a kan ma'aikatan aikin, ciki har da babban injiniya. Ana iya cewa hatsarin ya fito ne daga al'adun aminci na kasawa, ba kawai a cikin tsire-tsire na Chernobyl ba, amma a ko'ina cikin tsarin Soviet, aiki da ƙungiyoyi masu kula da makamashin nukiliya wanda ya wanzu a wancan lokacin. : 24

Kyakkyawan ƙarancin ƙarancin

Reactor yana da ƙaƙƙarfan ƙaƙƙarfan ƙaƙƙarfan ƙaƙƙarfan ƙaƙƙarfan ƙaƙƙarfan ƙaƙƙarfan ƙima. Ƙididdigar ɓoyayyiyar ɓarna shine ma'auni na yadda reactor ke amsa ƙarar samuwar tururi a cikin mai sanyaya ruwa. Yawancin sauran na'urori na reactor suna da ƙarancin ƙima, watau yanayin amsawar nukiliya yana raguwa lokacin da kumfa mai tururi ya fito a cikin mai sanyaya, tunda ƙarancin tururi yana ƙaruwa, ƙarancin neutrons suna raguwa. Neutrons masu sauri ba su da yuwuwar raba atom ɗin uranium, don haka reactor yana samar da ƙarancin ƙarfi (sakamako mara kyau).

Reactor na Chernobyl na RBMK, duk da haka, ya yi amfani da ƙaƙƙarfan graphite a matsayin mai daidaita neutron don rage jinkirin neutrons, kuma ruwan sanyaya ya zama mai ɗaukar neutron. Don haka neutrons ana sarrafa su ta hanyar graphite ko da tururi kumfa ya fito a cikin ruwa. Bugu da ƙari kuma, saboda tururi yana ɗaukar neutron ɗin da sauri fiye da ruwa, haɓaka ɓoyayyun yana nufin cewa mafi matsakaicin neutrons suna iya raba atom na uranium, ƙara ƙarfin wutar lantarki. Wannan na iya haifar da ingantaccen tsarin sake farfadowa (wanda aka sani da ingantaccen ƙarfin wutar lantarki) wanda ke sa ƙirar RBMK ba ta da ƙarfi sosai a ƙananan matakan wutar lantarki, kuma mai saurin haɓaka ƙarfin kuzari zuwa matakin haɗari. Ba wai kawai wannan hali ya sabawa fahimta ba, wannan kadarorin na reactor a wasu sharudda ba su san ma'aikatan ba.

Tsarin sandar sarrafawa

Matsakaicin reactor ya kasance tsayin mita 7 (ƙafa 23). Rabin na sama na sandar mita 7 (ƙafa 23) shine boron carbide, wanda ke ɗaukar neutrons kuma ta haka yana rage yawan amsawa. Bangaren ƙasa na kowane sandar sarrafawa shine mai juyawa graphite mita 4.5, wanda ya hana tashoshi cikawa da ruwa lokacin da aka cire sanduna.

Kuskuren ya kasance a cikin sarari na mita 1.25 (4.1-foot) tsakanin ƙasan mai sauyawa da ƙasan mai sarrafawa, ma'ana cewa mafi ƙasƙanci na tashar sarrafawa an cika shi da ruwa, maimakon graphite. :: 123  Tare da wannan ƙirar, lokacin da aka saka sanduna daga matsayi mai cikakken janyewa don dakatar da amsawa akan siginar AZ-5, graphite ya kawar da ruwa mai shan neutron, yana haifar da ƙananan neutrons da za a sha kuma yana ƙara saurin amsawa. A farkon 11 zuwa 14 seconds na tura sandar har sai boron ya kasance a matsayi, ikon reactor a fadin bene na reactor na iya ƙaruwa maimakon raguwa. Wannan fasalin aikin sandar sarrafawa ya saba wa fahimta kuma ba a san shi da masu aiki da reactor ba.

Gudanarwa da rashi na aiki

An lura da sauran gazawar a cikin ƙirar reactor RBMK-1000, kamar yadda rashin bin ƙa'idodin da aka yarda da shi tare da buƙatun amincin injin nukiliya. Yayin da INSAG-1 da INSAG-7 suka ba da rahoton duk sun gano kuskuren ma'aikaci a matsayin batun damuwa, INSAG-7 ta gano cewa akwai wasu batutuwa masu yawa waɗanda ke ba da gudummawar abubuwan da suka haifar da lamarin. Wadannan abubuwan da ke taimakawa sun hada da:

1. Ba a tsara shuka ba don ka'idodin aminci kuma an haɗa su da siffofi marasa aminci
2. "An yi bincike mara kyau na aminci"
3. Akwai "rashin kulawa ga sake dubawa mai zaman kansa"
4. "Tsarin aiki ba a kafa shi da gamsarwa a cikin bincike na aminci"
5. Bayanan tsaro ba su da isasshen kuma suna sadarwa yadda ya kamata tsakanin masu aiki, da kuma tsakanin masu aiki da masu zanen kaya
6. Masu aiki ba su fahimci bangarorin tsaro na shuka ba
7. Masu aiki ba su cika bukatun tsari na aiki da gwaji ba
8. Tsarin mulki bai isa ba don magance matsin lamba don samarwa yadda ya kamata
9. Akwai "rashin al'adun tsaro a cikin al'amuran nukiliya a matakin kasa da na cikin gida"

Dubi kuma

• Jerin labaran da suka shafi Chernobyl