Uranium ni iki kandi igira uruhe ruhare mu ntwaro kirimbuzi no gukora ingufu?

Intambara ya Amerika na Israel kuri Iran yongeye kugarukwaho kubera ingingo y'intwaro kirimbuzi n'akaga ko kuzigwizaho.

Kugeza ubu nk'uko bivugwa n'ikigo Union of American Scientists and the International Arms Control Association, ibihugu icyenda gusa ni byo bifite intwaro kirimbuzi. Ibyo ni;

Iran nta ntabwo kirimbuzi igira.

Intwaro kirimbuzi zimaze gukoreshwa kabiri gusa mu mateka, ubwo Amerika yaziteraga i Hiroshima na Nagasaki muri Kanama(8) 1945.

Uwo mwaka wagiye kurangira abantu 140,000 bamaze gupfa i Hiroshima naho 74,000 barapfuye i Nagasaki.

Hejuru yo guturika guteye ubwoba n'ubushyuhe bukomeye cyane, intwaro kirimbuzi zirekura imishwarara (radiation) itera indwara zikomeye kubera uburozi iba yifitemo, kandi ingaruka z'ibi bisasu zigaragara na nyuma y'igihe kinini bituritse.

Uranium, ni cyo kinyabutabire cy'ibanze gikoreshwa mu gucura ibisasu kirimbuzi.

Ariko mbere na mbere reka tubanze tumenye ngo Uranium yavumbuwe ite kandi abasivile bayikoreshaga bate?

Uranium ni iki?

Ni ikinyabutabire kiremereye gifite ibara ryera rijya gusa na 'silver'. Ikirango cyayo ku rutonde rw'ibinyabutabire ni "U" kandi umubare 'atomic' wayo ni 92.

Uranium ubusanzwe iboneka mu butaka ahantu hari uruhurirane rw'itaka, ibibuye n'amazi igacukurwa ikagurishwa ari amabuye bikekwa ko arimo uranium azwi nka Uraninite.

Uranium nyayo iba isa n'umweru ushashagirana cyangwa nk'icyuma cya 'silver', ariko amabuye arimo uranium iyo agicukurwa aba ajya gusa n'umuhondo, umukara, icyatsi, ikigina…bitewe n'imiterere y'aho yacukuwe.

Amabuye abonekamo Uranium ashobora gucukurwa hasi cyane mu birombe, iyo amaze kuboneka barayashwanyaguza kugira ngo batandukanye uranium n'ibindi binyabutabire biba biyikikije.

Minisiteri y'ingufu ya Amerika ivuga ko Uranium yacukuwe ibikwa ikagurishwa mu buryo buzwi nka 'uranium oxide' izwi kandi nka "yellowcake".

Uranium igira ireme rikomeye cyane, hafi garama 19 kuri santimetero cube imwe.

Urubuga rwa World Nuclear Association ruvuga ko nubwo uranium ari nkeya mu mibumbe igaragiye izuba ariko nko mu mubumbe w'isi iki kinyabutabire kigira uruhare runini mu bushyuhe bwawo, ubushyuhe bugira uruhare mu kunyeganyega kw'ibice bigize uyu mubumbe kuzwi nka 'movement of tectonic plates'.

Iyo soko y'amakuru ivuga kandi ko Uranium ishobora kuba yarabayeho mbere y'uko isi ubwayo ibaho, mu gihe cyo guturika guhambaye kwitwa supernovae maze nyuma igahinduka ikinyabutabire.

Mu gihe cyahise, uranium yabonekaga cyane cyane mu bucukuzi bwa gakondo aho yakurwaga mu mabuye yacukuwe. Ariko uyu munsi igice kinini cya Uranium icukurwa ku isi kiboneka mu bucukuzi bwifashishije ikorenabuhanga ryo kuyitandukanya n'ibindi binyabutabire ikiri mu birombe, ubuhanga buzwi nka 'situ extraction'.

Ni nde wavumbuye Uranium?

Umudage w'umuhanga mu butabire Martin Heinrich Klaproth niwe muntu wa mbere watangaje uranium, hari mu 1789.

Martin yavumbuye iki kinyabutabire ubwo yarimo asesengura ibipimo by'amabuye ya "spiralite" byari bivuye mu birombe bicukurwamo icyuma cya 'silver' mu karere ko mu bwamo bwa Bohemia, ubu ni mu gihugu cya Czech Republic.

Uwo muhanga ntabwo yabashije gutandukanya Uranium ngo ize nk'icyuma ukwacyo, ahubwo yabashije gutandukanya kimwe mu biyigize acyita "Uran" izina riva ku mubumbe wa Uranus, wari umaze imyaka micyeya uvumbuwe.

Uranium icyo gihe yakoreshwaga mu gushyira amabara ku birahure, gukora amafoto no gucyesha ibikoresho by'ibumba (ceramics) imyaka myinshi mbere y'uko bavumbura ubushobozi bw'iki kinyabutabire bwa 'radio-activity' cyangwa se ingufu z'imirasire.

Ubushobozi bw'izo mbaraga za Uranium bwagiye kuboneka mu 1885 ubwo Wilhelm Roentgen umudage w'umuhanga mu bugenge (phyisique) yavumburaga imirasire ya X-rays arimo kwiga ku kunyura kw'amashanyarazi mu kirahure kirimo ubusa.

Umwaka umwe nyuma yaho, umufaransa w'umuhanga mu bugenge Henri Becquerel yavumbuye ko uduce tumwe twa Uranium turekura imirasire itaboneka ishobora ifite imbaraga zikomeye kandi inaboneka hadakenewe urumuri. Byabaye itangiriro ryo kumva ubushobozi bwa 'radioactivity' bwa Uranium.

Mu 1898, Pierre na Marie Curie bakoresheje bwa mbere ijambo "radiogenesis" ku bw'icyo kintu (phenomenon), muri uwo mwaka kandi babashije gutandukanya ibinyabutabire bya polonium na radium bivuye muri "Spiralite". Radium ikoreshwa mu buvuzi, by'umwihariko mu kuvura cancers zimwe na zimwe.

Mu 1900, umuhanga mu bugenge w'umufaransa, Paul Villard, yavumbuye ubwoko bwa gatatu bwa 'radiation' bise gamma rays, nabwo kimwe na X-rays, bifute imbaraga zikomeye zo gutobora.

Uku kuvumbura kwafashije abahanga muri siyanse kumva neza kurushaho amoko ya 'radiation', arimo alpha particles, beta particles, na gamma rays.

Igisasu kirimbuzi, n'imbaraga nziza mu buvuzi

Mu myaka ya 1930 no mu ntangiriro z'iya 1940, kumva ibijyanye no gushongesha kuvamo ingufu kirimbuzi byarihuse.

Abahanga basobanukiwe ko gutandukanya 'atomic nucleus' z'iki kinyabutabire bishobora gutanga ingufu nyinshi cyane, mu gihe bikozwe mu buryo runaka, bikaganisha ku gukabuza infugu kirimbuzi.

Mu ntambara ya kabiri y'isi ubu bushakashatsi bwihutishijwe cyane n'abanyamerika n'abongereza maze bugeza ku gukora igisasu gifite izo mbaraga za nikleyeri, ari cyo tuzi nk'igisasu kirimbuzi.

Umushinga w'ibanga wa Manhattan Project wakorewe mu butayu bwa New Mexico muri Amerika ni wo wageze ku gucura bene icyo gisasu.

Mu 1945 nibwo icyo gisasu cyari kirangiye. Muri Nyakanga(7) uwo mwaka, igisasu cya mbere bise Trinity cyamurikiwe abategetsi ba Amerika, maze mu kwezi kwakurikiyeho kwa Kanama(8) batera ibisasu bibiri bari bamaze kugeraho i Hiroshima na Nagasaki mu Buyapani.

Uyu munsi, Uranium ikoreshwa nk'ikintu cy'ibanze mu mashini zizwi nka 'nuclear reactors' kugira ngo itange amashanyarazi.

Ikoreshwa kandi mu buryo buziguye cyangwa butaziguye mu gukora ibizwi nka 'radioactive isotopes' zifashishwa mu buvuzi, inganda, igisirikare n'ubushakashatsi bunyuranye.

Uranium itunganyijwe byo ku rwego rwo hejuru ni yo y'ibanze ikoreshwa mu nkabuzo (reactors) zikora intwaro kirimbuzi, cyangwa gutwara amato manini cyane.

Naho Uranium itungayijwe ku rugero ruciriritse ni yo ikoreshwa mu bikorwa by'iterambere nk'ubuvuzi, amashanyarazi n'ibindi.

Ikigo International Atomic Energy Agency kivuga ko 'reactors' z'ubushakashatsi zikoreshwa mu kuvana 'neutrons' muri Uranium zifashishwa mu nganda n'ubuvuzi.

Kimwe mu bizwi cyane biva mu gutunganya uranium ikoreshwa mu buvuzi ni 'isotope molybdenum-99' igerwaho mu gushyushya uranium-235 mu nkabuzo (reactors).

Iyo 'molybdenum-99' nyuma icikamo 'technetium-99m', iyo na yo ni 'radioactive isotope' ikoreshwa cyane mu bigendanye n'amashusho afatwa kwa muganga (medical imaging), by'umwihariko mu gufotora no kureba indwara ziri mu mubiri nka cancer cyangwa indwara z'umutima.

Ikigo International Atomic Energy Agency kivuga ko hejuru ya 80% by'ibikoresho bya 'medical imaging' bikoreshwa ku mwaka mu kureba bene ziriya ndwara bishoboka kubera imashini zigezweho zikoresha uranium yatunganyijwe ikavamo ingufu za nikleyeri zifashishwa mu bikorwa nk'ibi byiza.

Ibihugu byinshi bya Afurika, birimo n'u Rwanda, ubu bigambiriye gukoresha bene ziriya mbaraga ziva kuri uranium muri ibyo bikorwa by'iterambere.

Naho Amerika, irimo kurwanya Iran – igihugu gikungahaye kuri Uranium – ivuga ko ishaka kuyambura ubushobozi bwose bwo gukoresha Uranium ngo na yo yubake igisasu kirimbuzi.