{"id":19,"date":"2011-03-26T15:02:23","date_gmt":"2011-03-26T13:02:23","guid":{"rendered":"http:\/\/www.tammilehto.info\/blogi\/2011\/03\/26\/fukushima-jo-tshernobyl-luokkaa\/"},"modified":"2011-03-26T15:02:23","modified_gmt":"2011-03-26T13:02:23","slug":"fukushima-jo-tshernobyl-luokkaa","status":"publish","type":"post","link":"http:\/\/r921017x.beget.tech\/blogi\/2011\/03\/26\/fukushima-jo-tshernobyl-luokkaa\/","title":{"rendered":"Fukushima jo Tshernobyl-luokkaa"},"content":{"rendered":"
Saksalaisen ydinvoima-asiantuntijan Helmut Hirschin mukaan Fukushimasta on p\u00e4\u00e4ssyt ymp\u00e4rist\u00f6\u00f6n jo niin paljon radioaktiivisuutta, ett\u00e4 se on IAEA:n INES-asteikolla luokiteltava vakavuusasteeltaan 7:ksi eli kaikkein vakavimmaksi onnettomuudeksi. Fukushimassa on n\u00e4in ollen tapahtunut saman luokan onnettomuus kuin Tshernobyliss\u00e4 vuonna 1986. INES-asteikolla onnettomuus on luokkaa 7, jos radioaktiivisia aineita p\u00e4\u00e4see ilmaan enemm\u00e4n kuin 20 000 TBq (terabecquereli\u00e4) jodi-131:t\u00e4 vastaava m\u00e4\u00e4r\u00e4. Fukushimasta oli 23.3. menness\u00e4 p\u00e4\u00e4ssyt pelk\u00e4st\u00e4\u00e4n radioaktiivista jodia ja cesiumia jo 500 000 TBq jodi-131-ekvivalenttia. Ja p\u00e4\u00e4st\u00f6t vain jatkuvat. Itseasiassa, jokaisesta Fukushiman kolmesta onnettomuusreaktorista on p\u00e4\u00e4ssyt yli 100 000<\/font> TBq jodi-131-ekvivalenttia<\/font>. Toisin sanoen Fukushimassa on tapahtunut kolme Tshernobyl-luokan onnettomuutta. Alla asiasta tarkemmin.<\/p>\n

http:\/\/www.greenpeace.org\/international\/PageFiles\/285388\/greenpeace_hirsch_INES_report_25032011.pdf<\/a><\/font><\/p>\n

Fukushima \u2013 INES scale rating
\n23 March 2011
\nHelmut Hirsch
\n_________________________________________________________
\nAim and structure of the INES scale
\nIn 1990 the International Nuclear and Radiological Event Scale (INES) was developed
\nthrough international experts, summoned via the IAEA and the nuclear agency of the
\nOECD (OECD \/ NEA). The aim of the INES scale is to provide prompt and consistent
\ninformation covering the relevance of an event connected to radioactive material.
\nThe INES scale covers eight levels:
\nlevel 7 major accident
\nlevel 6 serious accident
\nlevel 5 accident with wider consequences
\nlevel 4 accident with local consequences
\nlevel 3 serious incident
\nlevel 2 incident
\nlevel 1 anomaly
\nlevel 0 no safety significance
\nChernobyl in 1986 was rated an INES 7 event, Three Mile Island in 1979 an INES 5 event.
\nThe rating follows three main criteria areas: offsite radiological effects, onsite radiological
\neffects, impairment of safety measures.
\nFor accidents (level 4 \u2013 7) the radiological effects outside the plant are primarily relevant.
\nCriteria for INES event rating
\nAccording to the INES handbook the radiological impacts outside a nuclear complex can
\nbe described through (a) the release of radioactive material into the atmosphere and (b)
\nthe radiation doses.
\nFollowing (a) will be applied. This is because releases can be estimated more precisely
\ncompared to received radiation doses. Besides this an INES rating of 6 is the maximum
\nwhen based on radiation doses only.
\nFor the rating the releases into the atmosphere are in J-131 equivalents. Specific factors
\nfor different nuclides are given to specify the J-131 equivalent. The factor for rare gases,
\nfor example, is 0, for Cs-137 it is 40 and for Pu-239 the factor is 10,000.
\nINES level 7 \u2013 more than a couple of 10,000 J-131 equivalents
\nINES level 6\u2013 some 1,000 to a couple of 10,000 TBq J-131 equivalents
\nINES level 5\u2013 some 100 to a couple of 1,000 TBq J-131 equivalents
\nINES level 4\u2013 some 10 to a couple of 100 TBq J-131 equivalents
\nThe IAEA states it not being appropriate to use exact numbers to define ratings as early
\nestimations are inevitably rough estimations only. To provide some orientation the IAEA
\nsuggests 50,000, 5,000 and 500 TBq.
\nAdaptability to a number of reactors
\nThe handbook suggests the IAEA generally assuming that the INES scale of is applied to
\nan event in one specific block of a nuclear power station. In general practical experience
\nconfirms this.
\nHow to deal with a combination of evens (like in Fukushima) remains open in the
\nhandbook.
\nAs mentioned above, the aim of the INES scale is to provide prompt and consistent
\ninformation covering the relevance of an event. Without doubt the overall release during
\nan event is the most important part of information for the public. The overall release is
\nrelevant for air, ground, water, foodstuff contamination. Therefore it reflects the idea of the
\nINES scale to take into account all events in a nuclear complex (like Fukushima Daiichi)
\nwhere releases of a number of reactors overlap within a short time period, and rate them
\ntogether. Additionally the course of events interlink through contamination, explosions,
\nfires, direct radiation.
\nBeside this an individual rating can also be reasonable approach to add transparency to
\nthe course of events.
\nFukushima releases to date
\nThere have been estimations on releases from Fukushima Daiichi reactors, two are
\nknown to the author.
\nOn 22.03.2011 the French Institut de Radioprotection et de S?\u00c2\u00bbret?\u00c2\u00a9 Nucl?\u00c2\u00a9aire (IRSN)
\n(www.irsn.fr<\/a>) published an estimation covering reactors 1 \u2013 3 and the time period between
\n12.03.2011 and 22.03.2011: 90,000 TBq j-131, 10,000 TBq Cs-137 (plus specification
\ncovering other nuclides).
\nOn 22.03.2011 the Austrian Zentralanstalt f? 1\/4 r Meteorologie und Geodynamik (ZAMG)
\n(www.zamg.ac.at<\/a>) published estimations covering the total release of J-131 and Cs-137 in
\nthe first four days. This estimation has been specified on the 23.03.2011: 400,000 TBq J-
\n131, 85,000 TBq Cs-137.
\nFor J-131 the author did further estimations. Based on core inventory specifications and
\nmedium burn up (source: WNIH 2010) a J-131 inventory of 1,000,000 TBq for block 1 at
\nthe time of the shutdown due to the earthquake and for bocks 2 and 3 1,800,000 TBq
\neach seems to be reasonable.
\nA release of 2.75% (equalling a non-filtered release during containment venting) results in
\nan overall release of approx. 125,000 TBq J-131 (summing up the three blocks).
\nThese numbers closely represent IRSN numbers and will be used as the base for further
\nestimations. It is not to be assumed that this results in any kind of overestimation.
\nRadioactive decay is not taken into account by the author. It remains unclear whether it
\nwas taken into account by IRSN or ZAMG. Radioactive decay is \u2013 having the time period
\nin mind \u2013 only relevant for J-131 (half life: eight days), not for Cs-137 (half life: 30 years).
\nFukushima
\nThe release of J-131 and Cs-137 alone (as stated through IRSN) corresponds to a
\n500,000 TBq J-131 equivalent.
\nTaken all Fukushima Daiichi reactors into consideration this is obviously an INES 7 event.
\nEach reactor considered individually results in more than 100.000 TBq per block (all
\nreleases divided by three and proportionally to the inventory) \u2013 three INES 7 events. If the
\nrelease is not divided proportionally different ratings are possible.
\nAs the Cs-137 release is the biggest share the above assessment remains unchanged,
\neven when the radioactive decay is taken into consideration.<\/font><\/div>\n","protected":false},"excerpt":{"rendered":"

Saksalaisen ydinvoima-asiantuntijan Helmut Hirschin mukaan Fukushimasta on p\u00e4\u00e4ssyt ymp\u00e4rist\u00f6\u00f6n jo niin paljon radioaktiivisuutta, ett\u00e4 se on IAEA:n INES-asteikolla luokiteltava vakavuusasteeltaan 7:ksi eli kaikkein vakavimmaksi onnettomuudeksi. Fukushimassa on n\u00e4in ollen tapahtunut saman luokan onnettomuus kuin Tshernobyliss\u00e4 vuonna 1986. INES-asteikolla onnettomuus on … Lue loppuun →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[9,8],"tags":[],"_links":{"self":[{"href":"http:\/\/r921017x.beget.tech\/blogi\/wp-json\/wp\/v2\/posts\/19"}],"collection":[{"href":"http:\/\/r921017x.beget.tech\/blogi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/r921017x.beget.tech\/blogi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/r921017x.beget.tech\/blogi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/r921017x.beget.tech\/blogi\/wp-json\/wp\/v2\/comments?post=19"}],"version-history":[{"count":0,"href":"http:\/\/r921017x.beget.tech\/blogi\/wp-json\/wp\/v2\/posts\/19\/revisions"}],"wp:attachment":[{"href":"http:\/\/r921017x.beget.tech\/blogi\/wp-json\/wp\/v2\/media?parent=19"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/r921017x.beget.tech\/blogi\/wp-json\/wp\/v2\/categories?post=19"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/r921017x.beget.tech\/blogi\/wp-json\/wp\/v2\/tags?post=19"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}