![\"\"](\"https:\/\/himinnoghaf.is\/mengunsjavar\/wp-content\/uploads\/radioind.png\")
<\/a>Mynd 6.3. Helstu ferlar \u00ed kjarnorkui\u00f0na\u00f0i.<\/p><\/div>\n
6.3.2. Kjarnorkuver<\/h4>\n
\u00cd kjarnorkuverum er framleidd raforka (mynd 6.4). Me\u00f0 ke\u00f0juverkandi<\/span> kjarnasundrun \u00faran\u00edums (U-235) myndast orka sem n\u00fdtt er til a\u00f0 hita vatn. Vatni\u00f0 ver\u00f0ur a\u00f0 gufu sem kn\u00fdr gufuhverfla og til ver\u00f0ur rafmagn. \u00cd kjarnorkuveri er n\u00e6gjanlegu magni af U-235 komi\u00f0 fyrir \u00ed eldsneytisst\u00f6ngum og \u00feeim komi\u00f0 fyrir \u00ed vatnsba\u00f0i \u00ed kjarnaofninum innan \u00ed \u00fer\u00fdstihylki<\/span><\/span>. \u00deegar nifteindir lenda \u00e1 \u00faran\u00edumkjarna klofnar hann og vi\u00f0 \u00fea\u00f0 myndast l\u00e9ttari geislavirkar afur\u00f0ir kjarnasundrunarinnar auk 2-3 nifteinda. \u00de\u00e6r nifteindir sem myndast rekast svo \u00e1 a\u00f0ra \u00faran\u00edumkjarna og ke\u00f0juverkandi kjarnasundrun \u00e1 s\u00e9r sta\u00f0. Nifteindirnar rekast einnig \u00e1 afur\u00f0ir kjarnasundrunarinnar og til ver\u00f0a enn a\u00f0rar sundrunarafur\u00f0ir. Vi\u00f0 kjarnasundranirnar myndast mikil orka sem hitar vatni\u00f0 og myndar gufu sem kn\u00fdr gufuhverfla. Til a\u00f0 st\u00fdra ferlinu eru nota\u00f0ar st\u00fdristangir og er h\u00e6gt a\u00f0 f\u00e6ra \u00fe\u00e6r til \u00ed kjarnaofni til a\u00f0 hra\u00f0a og h\u00e6gja \u00e1 ferlinu. Til a\u00f0 st\u00f6\u00f0va ferli\u00f0 eru st\u00fdristangirnar settar\u00a0alla lei\u00f0 ni\u00f0ur<\/span><\/span> \u00ed kjarnaofninum og gleypa \u00fe\u00e6r \u00fe\u00e1 allar nifteindirnar svo a\u00f0 ke\u00f0juverkunin rofnar. \u00deetta er til d\u00e6mis gert \u00feegar sl\u00f6kkva \u00fearf \u00e1 ofnunum. \u00der\u00fdstihylki\u00f0 og steinsteypt mannvirki\u00f0 utan um kjarnaofninn sem og vatnskerfi\u00f0 \u00fej\u00f3na \u00feeim tilgangi a\u00f0 koma \u00ed veg fyrir losun geislavirkra efna \u00fat \u00ed umhverfi\u00f0. \u00deegar sl\u00f6kkt er \u00e1 kjarnaofnum \u00fearf a\u00f0 d\u00e6la vatni um kerfi\u00f0 til a\u00f0 k\u00e6la eldsneytisstangirnar, \u00fev\u00ed a\u00f0 \u00fer\u00e1tt fyrir a\u00f0 sl\u00f6kkt s\u00e9 \u00e1 ofnunum halda ni\u00f0urbrotshv\u00f6rfin \u00e1fram me\u00f0 tilheyrandi hitamyndun. Ef vatninu er ekki haldi\u00f0 \u00ed hringr\u00e1s ofhitnar \u00fea\u00f0 umhverfis eldsneytisstangirnar og s\u00fd\u00f0ur burt. \u00de\u00e1 er engin k\u00e6ling virk lengur og eldsneytisstangirnar geta br\u00e1\u00f0na\u00f0 og or\u00f0i\u00f0 a\u00f0 eins konar geislavirkri kviku (e. meltdown) sem getur br\u00e6tt sig \u00ed gegnum b\u00e6\u00f0i \u00fer\u00fdstihylki\u00f0 og hl\u00edf\u00f0arhylki\u00f0 og \u00e1tt \u00feannig grei\u00f0a lei\u00f0 \u00fat \u00ed umhverfi\u00f0. Flest kjarnorkuver n\u00fdta raforku til a\u00f0 halda k\u00e6livatninu \u00ed hringr\u00e1s \u2013 og \u00fea\u00f0 getur leitt til vandr\u00e6\u00f0a eins og kom \u00e1 daginn \u00ed Fukushima \u00e1ri\u00f0 2011.<\/p>\n Mynd 6.4. Til vinstri: \u00deegar nifteind rekst \u00e1 \u00faran\u00edumkjarna myndast l\u00e9ttari geislavirkar afur\u00f0ir og 2-3 nifteindir sem rekast \u00e1fram \u00e1 a\u00f0ra \u00faran\u00edumkjarna og\/e\u00f0a \u00e1 afur\u00f0ir kjarnasundrunar og enn a\u00f0rar afur\u00f0ir myndast. Til h\u00e6gri: Skemat\u00edsk mynd af kjarnorkuveri.<\/p><\/div>\n \u00deegar eldsneytisstangir hafa veri\u00f0 \u00ed notkun \u00ed 1-2 \u00e1r er magn \u00faran\u00edums or\u00f0i\u00f0 \u00fea\u00f0 l\u00edti\u00f0 a\u00f0 \u00fea\u00f0 vi\u00f0heldur ekki lengur ke\u00f0juverkandi kjarnasundrun. Eldsneytisst\u00f6ngunum er \u00fe\u00e1 skipt \u00fat fyrir n\u00fdjar. Notu\u00f0u eldsneytisstangirnar innihalda geislavirkar afur\u00f0ir kjarnasundrunarinnar \u00fe.\u00e1 m. pl\u00fat\u00f3n\u00edum, ses\u00edum, stront\u00edum og margt fleira. \u00de\u00e6r eru enn mj\u00f6g geislavirkar og \u00fearf \u00fev\u00ed a\u00f0 geyma \u00fe\u00e6r \u00ed vatni til k\u00e6lingar vi\u00f0 kjarnorkuveri\u00f0 \u00ed marga m\u00e1nu\u00f0i. \u00c1 \u00feeim t\u00edma minnkar geislavirknin talsvert. Eftir stendur geislavirkur \u00fargangur sem er h\u00e6ttulegur \u00ed langan t\u00edma, jafnvel \u00e1r\u00fe\u00fasundir. Ekki hefur enn tekist a\u00f0 leysa \u00fea\u00f0 vandam\u00e1l sem \u00feessi \u00fargangur skapar og oftast er hann geymdur vi\u00f0 kjarnorkuveri\u00f0 \u00e1 me\u00f0an veri\u00f0 er a\u00f0 leita a\u00f0 varanlegri lausn. \u00c1\u00f0ur fyrr var geislavirkum \u00fargangi s\u00f6kkt \u00ed hafi\u00f0 en sl\u00edk me\u00f0fer\u00f0 hefur veri\u00f0 b\u00f6nnu\u00f0 fr\u00e1 \u00fev\u00ed a\u00f0 Samingur um varnir gegn mengun hafsins vegna losunar \u00fargangsefna og annarra efna \u00ed \u00fea\u00f0<\/em> (Lund\u00fanarsamningurinn, sj\u00e1 kafla 8.3<\/a>) t\u00f3k gildi \u00e1ri\u00f0 1975. Stundum er kjarnorku\u00fargangur endurunninn og er hann \u00fe\u00e1 sendur \u00ed kjarnorkuendurvinnslust\u00f6\u00f0. Ein sl\u00edk var t.d. rekin \u00ed Sellafield \u00e1 Englandi.<\/p>\n A\u00f0fararn\u00f3tt laugardagsins 26. apr\u00edl 1986 var\u00f0 sprenging \u00ed kjarnaofni nr. 4<\/span><\/span>\u00a0\u00ed kjarnorkuverinu vi\u00f0 Chernobyl<\/span> <\/span>\u00ed \u00dakra\u00ednu<\/span><\/span>. Kjarnaofnarnir \u00ed Chernobyl voru af ger\u00f0inni RBKM (r. Reaktor Bolshoy Moshchnosty Kanalny) sem nota graf\u00edt til a\u00f0 h\u00e6gja<\/span><\/span> \u00e1 nifteindum <\/span>og hafa \u00feann galla a\u00f0 vera \u00f3st\u00f6\u00f0ugir \u00ed rekstri \u00feegar \u00feeir eru keyr\u00f0ir \u00e1 litlu afli. Veri\u00f0 var a\u00f0 pr\u00f3fa hvort h\u00e6gt v\u00e6ri a\u00f0 k\u00e6la ofn 4 ef kjarnorkuveri\u00f0 yr\u00f0i rafmagnslaust. R\u00f6\u00f0 mistaka og rangra \u00e1kvar\u00f0ana vi\u00f0 pr\u00f3funina, \u00e1samt h\u00f6nnunargalla \u00ed RBKM-kjarnaofninum, leiddi til sprengingarinnar. \u00c1kve\u00f0i\u00f0 var t.a.m. a\u00f0 halda pr\u00f3funinni \u00e1fram \u00fer\u00e1tt fyrir a\u00f0 \u00e1lagi\u00f0<\/span><\/span> \u00e1 ofninum v\u00e6ri skv. \u00f6ryggisreglum or\u00f0i\u00f0 of l\u00edti\u00f0 til a\u00f0 pr\u00f3funin m\u00e6tti fara fram, auk \u00feess sem sl\u00f6kkt haf\u00f0i veri\u00f0 \u00e1 ney\u00f0arkerfinu. \u00deegar starfsmenn ur\u00f0u \u00feess varir a\u00f0 \u00e1lagi\u00f0 var or\u00f0i\u00f0 of l\u00edti\u00f0 var brug\u00f0ist vi\u00f0 me\u00f0 \u00fev\u00ed a\u00f0 h\u00edfa st\u00fdristangirnar alla lei\u00f0 upp \u00ed kjarnaofninum. Vi\u00f0 \u00fea\u00f0 j\u00f3kst \u00e1lagi\u00f0 hins vegar alltof hratt og ofninn ofhitna\u00f0i. Starfsmenn reyndu a\u00f0 sl\u00f6kkva \u00e1 ofninum me\u00f0 ney\u00f0arrofa<\/span><\/span> en \u00fea\u00f0 var or\u00f0i\u00f0 of seint. Miki\u00f0 magn gufu mynda\u00f0ist og n\u00ed\u00f0\u00feungur hlemmur, sem loka\u00f0i ofninum, lyftist \u00feannig a\u00f0 geislavirk efni komust \u00fat \u00ed umhverfi\u00f0. \u00de\u00e1 komst s\u00farefni \u00ed ofninn og vi\u00f0 \u00fea\u00f0 kvikna\u00f0i \u00ed graf\u00edtinu. \u00deegar gufan komst \u00ed snertingu vi\u00f0 zirk\u00f3n\u00edum<\/span> <\/span>\u00ed eldsneytisst\u00f6ngunum mynda\u00f0ist vetni sem olli geysilegri sprengingu. Gr\u00ed\u00f0arlegt magn geislavirkra efna komst \u00fear me\u00f0 \u00f3hindra\u00f0 \u00fat \u00ed andr\u00famslofti\u00f0. Eldar brunnu og t\u00f3k marga daga a\u00f0 r\u00e1\u00f0a ni\u00f0url\u00f6gum \u00feeirra. Einn starfsma\u00f0ur versins d\u00f3 samstundis og fleiri fundu fyrir mikilli geislaveiki \u00e1 n\u00e6stu d\u00f6gum. \u00dea\u00f0 sama m\u00e1 segja um f\u00f3lki\u00f0 \u00ed Pripyat \u00fear sem margir starfsmenn kjarnorkuversins bjuggu \u00e1samt fj\u00f6lskyldum s\u00ednum. Sl\u00f6kkvili\u00f0smenn sem kalla\u00f0ir voru \u00fat komu \u00e1n hl\u00edf\u00f0arfatna\u00f0ar \u00e1 sta\u00f0inn. \u00deeir l\u00e9tust allir \u00e1 n\u00e6stu d\u00f6gum e\u00f0a vikum, \u00e1samt nokkrum starfsm\u00f6nnum versins, en samtals l\u00e9tust 30 \u00e1 \u00feessum fyrstu vikum. Vi\u00f0 t\u00f3ku bj\u00f6rgunarst\u00f6rf vi\u00f0 st\u00f3rh\u00e6ttulegar a\u00f0st\u00e6\u00f0ur. \u00cd ofninum h\u00e9ldu um 1.200 tonn af geislavirkri kviku \u00e1fram a\u00f0 brenna vi\u00f0 meira en 5.000\u00b0C og senda geislavirk efni \u00fat \u00ed andr\u00famslofti\u00f0. Kvikan haf\u00f0i myndast \u00fev\u00ed a\u00f0 k\u00e6livatni\u00f0 haf\u00f0i allt gufa\u00f0 upp og sloppi\u00f0 \u00fat \u2013 \u00fear me\u00f0 var engin k\u00e6ling og eldsneyti\u00f0 br\u00e1\u00f0na\u00f0i. Flogi\u00f0 var \u00e1 \u00feyrlum yfir gapandi kjarnaofninn og \u00fdmsum efnum s.s. sandi og b\u00f3rs\u00fdru varpa\u00f0 ni\u00f0ur til a\u00f0 reyna a\u00f0 k\u00e6fa eldinn og st\u00f6\u00f0va \u2013 e\u00f0a alla vega draga \u00far \u2013 losun geislavirkra efna. \u00de\u00e1 var bl\u00fdi varpa\u00f0 ni\u00f0ur til a\u00f0 reyna a\u00f0 draga \u00far hitanum. \u00deyrluflugmenn voru kalla\u00f0ir heim fr\u00e1 v\u00edgst\u00f6\u00f0vunum \u00ed Afganistan til a\u00f0 taka \u00fe\u00e1tt \u00ed \u00feessu h\u00e6ttulega verkefni. Geislunin fyrir ofan kjarnaofninn var svo mikil a\u00f0 flugmennirnir fundu fyrir einkennum geislaveiki (\u00f3gle\u00f0i, uppk\u00f6st, ni\u00f0urgangur).<\/p>\n Mynd 6.5. Vinstra megin: Inni \u00ed stj\u00f3rnst\u00f6\u00f0 kjarnaofns 4. H\u00e6gra megin: N\u00fd hl\u00edf\u00f0arbygging til a\u00f0 hindra losun geislavirkra efna fr\u00e1 ofni 4 var tekin \u00ed notkun \u00e1ri\u00f0 2017 (31 \u00e1ri eftir slysi\u00f0).<\/p><\/div>\n H\u00e6tta var \u00e1 a\u00f0 kvikan myndi br\u00e6\u00f0a sig \u00ed gegnum \u00fer\u00fdsti- og hl\u00edf\u00f0arhylkin. Fyrir ne\u00f0an kjarnaofninn haf\u00f0i safnast saman talsvert vatn (sl\u00f6kkvivatn eftir a\u00f0ger\u00f0ir sl\u00f6kkvili\u00f0sins) og ef kvikan hef\u00f0i n\u00e1\u00f0 \u00feanga\u00f0 hef\u00f0i \u00f6nnur sprenging geta\u00f0 \u00e1tt s\u00e9r sta\u00f0, jafnvel enn st\u00e6rri en s\u00fa fyrri. \u00der\u00edr starfsmenn voru \u00fev\u00ed sendir til a\u00f0 hleypa vatninu burt. \u00deeir ur\u00f0u a\u00f0 \u00fej\u00f3\u00f0hetjum fyrir viki\u00f0 en li\u00f0u fyrir \u00e1hrif geislunarinnar \u00fea\u00f0 sem eftir var \u00e6vinnar. \u00de\u00e1 voru grafin g\u00f6ng a\u00f0 kvikunni til a\u00f0 k\u00e6la hana ni\u00f0ur. A\u00f0 \u00fev\u00ed verki komu um 10.000 n\u00e1mumenn sem unnu vi\u00f0 \u00f3tr\u00falega erfi\u00f0ar a\u00f0st\u00e6\u00f0ur: hita, raka, l\u00e1gan s\u00farefnisstyrk og mikla geislavirkni. Einnig var hr\u00f3fla\u00f0 upp hl\u00edf\u00f0arbyggingu yfir kjarnaofn 4 til a\u00f0 draga \u00far geislavirkni \u00e1 sv\u00e6\u00f0inu svo h\u00e6gt v\u00e6ri a\u00f0 framlei\u00f0a \u00e1fram rafmagn \u00ed hinum \u00feremur ofnunum. \u00c1\u00f0ur en h\u00e6gt var a\u00f0 reisa hl\u00edf\u00f0arbygginguna \u00feurfti a\u00f0 fjarl\u00e6gja h\u00e1geislavirkt graf\u00edt sem l\u00e1 \u00e1 \u00feaki kjarnaofnsins. Eftir a\u00f0 r\u00f3b\u00f3tar h\u00f6f\u00f0u br\u00e6tt \u00far s\u00e9r vi\u00f0 verki\u00f0 \u00feurfti a\u00f0 f\u00e1 menn til a\u00f0 moka graf\u00edtinu af \u00feakinu. \u00deeir voru kalla\u00f0ir b\u00ed\u00f3r\u00f3b\u00f3tar <\/em>e\u00f0a lifandi v\u00e9lmenni<\/em>. Geislavirknin var svo mikil a\u00f0 hver ma\u00f0ur gat a\u00f0eins veri\u00f0 \u00ed um 45 sek\u00fandur \u00e1 \u00feakinu. \u00de\u00e1 \u00feurfti vi\u00f0komandi a\u00f0 taka s\u00e9r hl\u00e9 fr\u00e1 st\u00f6rfum og a\u00f0rir t\u00f3ku vi\u00f0. Hl\u00edf\u00f0arbyggingin, sem hr\u00f3fla\u00f0 var upp, \u00e1tti eftir a\u00f0 t\u00e6rast \u00e1 n\u00e6stu \u00e1rum og \u00fev\u00ed var hafist handa vi\u00f0 a\u00f0 byggja varanlega hl\u00edf\u00f0arbyggingu fyrir ofninn. S\u00fa risabygging \u00far st\u00e1li og steypu var tilb\u00fain \u00e1ri\u00f0 2017.<\/p>\n A\u00f0 hreinsunar- og bj\u00f6rgunarst\u00f6rfum komu yfir 500.000 manns, mest ungir karlmenn. \u00deeir f\u00f3rnu\u00f0u l\u00edfi s\u00ednu og heilsu fyrir almannaheill. \u00c1 fyrstu vikunum eftir slysi\u00f0 voru um 116.000 \u00edb\u00faar sem bjuggu innan 30 km fr\u00e1 kjarnorkuverinu fluttir burt af sv\u00e6\u00f0inu. \u00deetta samsvarar um 2.800 km2<\/sup> bannsv\u00e6\u00f0i. \u00c1 n\u00e6stu \u00e1rum var bannsv\u00e6\u00f0i\u00f0 st\u00e6kka\u00f0 \u00ed 4.300 km2<\/sup> og 200.000 \u00edb\u00faar \u00ed vi\u00f0b\u00f3t fluttir burt. Eftir slysi\u00f0 fj\u00f6lga\u00f0i m.a. f\u00e6\u00f0ingarg\u00f6llum og krabbameinstilfellum \u00ed \u00dakra\u00ednu og Belar\u00fas, einkum \u00ed skjaldkirtli.<\/p>\n F\u00f6studaginn 11. mars \u00e1ri\u00f0 2011 rei\u00f0 \u00f6flugur jar\u00f0skj\u00e1lfti yfir Japan. St\u00e6r\u00f0 skj\u00e1lftans var 9 \u00e1 Richter og \u00e1tti hann uppt\u00f6k s\u00edn ne\u00f0ansj\u00e1var r\u00e9tt undan austurstr\u00f6nd\u00a0Honshu<\/span><\/span>. Skj\u00e1lftinn olli gr\u00ed\u00f0arlegri ey\u00f0ileggingu \u00ed Japan, byggingar hrundu og vegir f\u00f3ru \u00ed sundur. Rafmagnslaust var\u00f0 v\u00ed\u00f0a. Um klukkustund s\u00ed\u00f0ar rei\u00f0 yfir Japan allt a\u00f0 39 metra h\u00e1 fl\u00f3\u00f0bylgja. Ey\u00f0ileggingin var\u00f0 enn meiri og fj\u00f6ldi f\u00f3lks d\u00f3 – fj\u00f6ldi l\u00e1tinna og \u00feeirra sem var sakna\u00f0 var meiri en 20.000.<\/p>\n Kjarnorkuveri\u00f0 \u00ed Fukushima<\/span><\/span> samanst\u00f3\u00f0 af 6 kjarnaofnum. Ofnar 1-3 voru \u00ed fullum rekstri \u00feegar skj\u00e1lftinn rei\u00f0 yfir, ofn 4 var \u00e1n eldsneytis og sl\u00f6kkt var \u00e1 ofnum 5-6. Vi\u00f0 jar\u00f0skj\u00e1lftann st\u00f6\u00f0va\u00f0ist kjarnorkuveri\u00f0\u00a0sj\u00e1lfkrafa<\/span> <\/span>\u00ed samr\u00e6mi vi\u00f0 \u00f6ryggis\u00e1\u00e6tlun. \u00deegar sl\u00f6kkt er \u00e1 kjarnaofnum halda ni\u00f0urbrotshv\u00f6rfin \u00ed eldsneytisst\u00f6ngunum \u00e1fram me\u00f0 tilheyrandi hitamyndun. Eldsneytisstangirnar \u00fearfnast \u00fev\u00ed \u00e1framhaldandi k\u00e6lingar.\u00a0Fl\u00f3\u00f0bylgjan<\/span><\/span>, sem rei\u00f0 yfir kjarnorkuveri\u00f0 \u00ed Fukushima, kaff\u00e6r\u00f0i hins vegar d\u00edsilv\u00e9larnar sem s\u00e1u um ney\u00f0ark\u00e6lingu og \u00fear af lei\u00f0andi \u00e1tti engin k\u00e6ling s\u00e9r sta\u00f0. Vegna hitans gufa\u00f0i k\u00e6livatni\u00f0 upp, eldsneytisstangirnar hitnu\u00f0u upp \u00ed 2.300\u00b0C, br\u00e1\u00f0na\u00f0u og myndu\u00f0u geislavirka kviku sem fann s\u00e9r lei\u00f0 ni\u00f0ur \u00far \u00fer\u00fdstihylkinu og ni\u00f0ur \u00e1 steypt g\u00f3lf hl\u00edf\u00f0arhylkisins. Vatnsgufan sem var\u00f0 til \u00feegar k\u00e6livatni\u00f0 gufa\u00f0i upp innih\u00e9lt b\u00e6\u00f0i geislavirk efni (jo\u00f0, ses\u00edum o.fl) sem l\u00e1ku \u00far l\u00f6sku\u00f0um eldsneytisst\u00f6ngunum og vetni sem mynda\u00f0ist \u00feegar gufan komst \u00ed snertingu vi\u00f0 zirk\u00f3n\u00edum. \u00deegar gufu\u00fer\u00fdstingurinn j\u00f3kst opnu\u00f0ust \u00f6ryggislokar og hluti gufunnar streymdi \u00ed k\u00e6livatnsgeyminn. Sm\u00e1m saman j\u00f3kst \u00fer\u00fdstingurinn \u00ed k\u00e6livatnsgeyminum og til a\u00f0 for\u00f0a rofi \u00e1 hl\u00edf\u00f0arhylkinu var \u00e1kve\u00f0i\u00f0 a\u00f0 hleypa gufunni \u00fat. Undir venjulegum kringumst\u00e6\u00f0um hef\u00f0i \u00f6ll gufan \u00e1tt a\u00f0 fara \u00fat um ney\u00f0arlokann en vetni\u00f0 n\u00e1\u00f0i a\u00f0 smj\u00faga um bygginguna vegna leka \u00e1 \u00fdmsum st\u00f6\u00f0um, l\u00edklega vegna skemmda sem ur\u00f0u \u00feegar jar\u00f0skj\u00e1lftinn rei\u00f0 yfir. Vandr\u00e6\u00f0in byrju\u00f0u \u00ed ofni 1. Ofarlega \u00ed byggingu hans hvarfa\u00f0ist vetni\u00f0 vi\u00f0 s\u00farefni og \u00far var\u00f0 vetnissprenging sem sprengdi upp \u00feak byggingarinnar \u00feann 12. mars. \u00dear me\u00f0 komust geislavirk efni \u00fat \u00ed umhverfi\u00f0. \u00deann 14. mars var\u00f0 samb\u00e6rileg sprenging \u00ed ofni 3. Brak \u00far ofni 3 \u00feeyttist vi\u00f0 sprenginguna a\u00f0 ofni 2 og olli skemmdum. \u00dea\u00f0 leiddi til losunar geislavirkra efna \u00fea\u00f0an. Geislavirk kvika mynda\u00f0ist \u00ed \u00f6llum \u00feremur ofnunum. Mest losun geislavirkra efna \u00fat \u00ed andr\u00famslofti\u00f0 hefur veri\u00f0 fr\u00e1 ofni 2 en einnig hefur talsvert magn af geislavirku vatni fr\u00e1 sv\u00e6\u00f0inu borist til sj\u00e1var. \u00deann 15. mars kvikna\u00f0i svo \u00ed ofni 4 vegna vetnis sem haf\u00f0i borist \u00feanga\u00f0 \u00ed gegnum lei\u00f0slu sem var sameiginleg fyrir ofna 3 og 4 (\u00fear var \u00fe\u00f3 ekkert eldsneyti sem gat br\u00e1\u00f0na\u00f0). \u00deegar k\u00e6likerfi ofnanna virku\u00f0u ekki lengur var s\u00fa \u00e1kv\u00f6r\u00f0un tekin a\u00f0 k\u00e6la ofnana me\u00f0 sj\u00f3. Sl\u00edkt er alls ekki \u00e6skilegt \u00fear sem sj\u00f3rinn er mj\u00f6g t\u00e6randi fyrir allan b\u00fana\u00f0. \u00c1 \u00feessum t\u00edma var \u00fe\u00f3 nau\u00f0synlegt a\u00f0 k\u00e6la ofnana hva\u00f0 sem \u00fea\u00f0 kosta\u00f0i.<\/p>\n<\/a>6.3.3. Kjarnorkuslysin \u00ed Chernobyl og Fukushima<\/h4>\n
<\/span>Slysi\u00f0 \u00ed Chernobyl<\/em><\/h6>\n
<\/a><\/span><\/em>Slysi\u00f0 \u00ed Fukushima<\/em><\/h6>\n