fighting to cool down other overheating fuel rods at the site christopher simons a professor at a tokyo university believes that while the danger remains great we're not talking about a neutron knowable. the damage to the fuel rods in this case will not cause a fire and again this is a key difference between the disaster going on at the moment though it is a disaster and the charitable incident this situation is a few rods can melt they can become oxidized and the rods are protected by as zucconi an hour lloyd coating and when it comes into contact with water a result is the production of a large amount of hydrogen which is of course explosive and that causes there a large explosion as we saw whether the radiation is coming from fukushima daiichi reactor number one or number three or more locally is a very important question to sort of i would hazard a guess that it's coming from fukushima daichi number one now there are different types of radiation being released into the atmosphere the good news is that a lot of the steam which takes in the explosion from eighty reactor number one building is re

christopher simons an associate professor at a tokyo university says that not everyone will be able to escape radiation exposure differences between the type of material being vented here and at daiichi a heat that is mostly steam. in charitable. vaporised graphite would have materialized as as dust or affected people as dust so staying inside would have been the best option the scene applies to daiichi but of course if the water condenses and enters the water supply it will make it undrinkable so people wearing masks keeping their doors and windows shut and keeping their air circulation systems such as he thing and air conditioner switched off is about all you can do i mean. that the government isn't has even excellent advice and that situation there really isn't anything else you can do the military and the firefighters who are in the vicinity working on this problem are certainly specially trained to deal with this kind of emergency so they're simply seem to be options one is to continue trying to deliver water to that reactor core and the second is simply to to evacuate as many peo

because it was simon says an associate professor said tokyo university explains how the design of the fukushima reactor could potentially contain the damage if the worst case scenario happens. this reactor is cooled entirely by as water. a meltdown is simply when the nuclear materials cannot be cool and the temperature rises in the containment area and the reactor materials themselves to the point at which they destroy the reactor that surrounds them of course these temperatures have to reach about five hundred degrees celsius for the metal and for the uranium itself probably in the order of eight hundred to one thousand degrees celsius. the good news is that that in the daiichi reactor is entirely water so the material venting into the atmosphere will likely just speaking radioactive steam in a case of sheer noble the reactor was moderated by graphite and. it holds the radiation and spritz much further as dust and gas so. that was the significant problem with sharon over the the neutron moderator and the airplane not react it was different and the radiation could spread much further

averting disaster as they contain radioactive materials because of simon's is a professor at the tokyo university he explains how an explosion might occur and what the worst case scenario could mean for local residents. but damage to the fuel rods in this case will not cause a fire and again this is a key difference between the disaster going on at the moment though it is a disaster and a chair an oval incident with the situation is a few rods can melt they can become oxidized and the rods are protected by zucconi in our loike coaching and when that comes into contact with water and result is the production of a large amount of hydrogen which is of course explosive and causes that a large explosion as we saw yesterday whether the radiation is coming from fukushima daiichi reactor number one or number three or more locally is a very important question is sort of i would hazard to guess that it's coming from fukushima daiichi number one now there are different types a great nation being released into the atmosphere good news is that a lot of the steam which exists in the explosion from daiichi reac

talking about that will be contaminated christopher assignments an associate professor at the tokyo university says that the radiation levels around fukushima are high and children may suffer the most from the exposure. people are being advised to stay in their homes and not drink water turn off their air conditioners . it sounds like the government is apparently prefer significant nuclear event and relation of the city was approximately one thousand. and that is about as much really a reason as a human body should have been one year and that's being released every hour so it seems like the radiation levels in the vicinity of the reactor are quite high the biological effects will depend on a number of factors of course the secret is a measure of biological impact rather than. just nuclear energy so for example if you are a larger person you have a larger body mass absorbing that same amount of radiation that suggests that the most vulnerable people will be children and the elderly people with a smaller body mass and or more we could body. i believe that measure of the one thousand my perceiver

university of tokyo professor says filters will remove radioactive substans bor eir is released. the agency says air inside the container will be tested for radioactivity. >> translator: at this moment, we have no confirmation that radioactive materialsas released. we within a radius of three kilometers to evacuate for safety reasons. >>> all nuclear power plants have some form of backup water system in case of an emergency, but as we've beenporting, the system failed at that nuclear power plant in fukushima prefecture. the mechanism to cool the reactor is called eccs or the emergency core cooling system. eccs is made up of a series of systems designed to safely shut down a nuclear reactor during serious accidents. it provides emergency cooling water to the core of the reactor to keep it from overheating. under normal conditions, heat is removed from a nuclear reactor by condensing steam after it passes through a turbine. the condensed steam is then fed back into the reactor and through the heat exchanger which keeps the reactor core at a constant temperature. the quake hit fukus

. >> translator: we are now joined by nuclear expert showita iwata of the university of tokyo. thank you very much for coming. first of all, what is the progress to -- of the effort to restore power? well, yesterday we've seen smoke. we still need to be very careful. some events still continue. however, generally speaking, the direction of the events are that we are -- things are becoming under control. the biggest difference we have from chernobyl is that the chain reaction shut down immediately after the event. therefore, it is not going to be a major accident, as we have seen in chernobyl. so temperature and substances are the subjects of control that needs to be controlled, and hoping that we can find solutions to this problem. >> translator: how about the water spraying operations? it's really important to fill the spent fuel with water. the water temperature has been down to 62 degrees centigrade or 42 degrees centigrade, relatively low. there has been no evaporation, and certain levels of water apparently has been kept. and the release of radioactive substances by coveri

tokyo electric power company. the photo taken near the number 4 reactor shows that pump trucks connected by hoses in a line that stretches from the pier to the first four reactors. a professor at university of tokyo graduate school has studied the photos and explained what we can learn from them. >> translator: we brought some of those photographs. these are the photos taken on the 20th. what can you interpret from this? you can see the four reactors from 1 to 4, and it's a very clear photograph. we can observe how severely damaged they are. >> the number 2 reactor, 1, 2, 3 are all the same, but we keep up hearing the term "trench." where is the trench? >> yes, there is a pit connected with a trench, and usually it is covered with a building but this swept with the wave. >> this hole we see here? >> yes. this is the opening of the trench. probably these square holes are the opening of the trench. >> there's the building here and there's the turbine building and there is a trench and this is the sea? >> that's right. >> the opening of the trench is very near the sea? >> yes, from here this is the turbine building of the number 2 reactor, number 1 reactor, and so the underneath this is ext

christopher simons a professor of international christian university in tokyo he shared his thoughts on what direction the situation in japan could take now. although the situation is quite dangerous it seems as though hopefully it will not be as serious as chernobyl this reactor is cooled entirely by water. i mean down is simply when the nuclear materials cannot be cooled and the temperature rises in the containment area and the reactor materials themselves to the point at which they destroy the reactor that surrounds them of course these temperatures have to reach about five hundred degrees celsius for the metal and for the uranium itself probably in the order of eight hundred to one thousand degrees celcius. the good news is that that in the daiichi reactor. is entirely water so the material venting into the atmosphere will likely be just steam radioactive steam in the case of sharon noble the reactor was moderated by graphite and ground. holds the radiation and splits much further as dust and gas so. that was the significant problem with sharon over the neutron moderator and ther

for your time christopher assignments from international christian university in tokyo hungry for the full story we've got it for us to the biggest issues get the human voice face to face with the news makers . this in. the. dust and the media radium inveighed against him in the simone number for the cars he goes to spread that artists. most dangerous. radiation that they exist in the nature. of our people in the vicinity of known differentiated so produce is so much and so many changes including pantsuit leukemia. right being out of the immune system. you don't have to have a college degree going to have to meet for an education to understand it you should read radioactive materials all over somebody's backyard that you've got a problem. on our hero. we hear it because our cash out spits out. god promised them this million belongs to us. you. will if they are still going to be thinking. and culturalism people will not believe that god is real estate agent so they took it as that is where you guys disguised as. under don't want to be this is the one. this is my god that. stuff. wealth

situation in japan from christopher simons associate professor at the international christian university in tokyo let's assignments as i've been there saying earlier their recent report is that there have been damage to fuel rods at the fukushima nuclear plant just as a what does that mean what kind of damage could the fuel rods be under right now we're trying to court where they're trying to call these installations as well earlier are these the ones prone to explosion because it has fuel can just tell us what it could have been. good afternoon and good evening from tokyo well yes the damaged fuel rods likely suggest because of that explosion we had yesterday in which a large amount of superheated steam escaped from reactor number one causing explosion which we saw are damage to the fuel rods in this case will not cause a fire and again this is a key difference between the disaster going on at the moment it is a disaster and a charitable incident in. ukraine where there will be the situation is situation is the furor adds can melt they can become oxidized and. roger protected by condom code and

. >>> experts from uc berkeley and university of tokyo teamed up to host a panel about the earthquake and tsunami and the melt down threat. they answered questions the audience had about the effects of radiation and whether it could reach the united states. kron 4's christy shows us the scene tonight. >> getting these questions about iodine tablets. here, absolutely not. period. >> this reactive material, our measurements in the united states will pick something ut. but at this pint, just because we can measure something doesn't mean it's dangerous. >> the farther you are from the source the radiation level drops significantly. if you are in california, 8,000- kilometers from the site, then you see it's -- we don't see any effects or neutrons emitted. >> how much radiation? i don't want to give estimate because i don't know. >> the crisis in japan is spiking demand in the united states for potassium iodide. it is is a cheap drug that can protect against one type of radiation damage. kron 4's christine connelly spoke withficials to answer some of your most common questions about the dr

assignment associate professor of international christian university in tokyo believes that people are now in grave danger of exposure. the people who will have the most danger will be the people who are working to stop this disaster at the moment that is the emergency workers and military personnel around the plant now they will be likely receiving quite high doses of radiation and the rest of the country and perhaps the world should start me feel quite grateful to the work that they are doing to stop this meltdown a situation in the north is very bad and i believe yes the government will require help from foreign experts from the international atomic energy agency from foreign governments who can supply material such as fuel and expert advice perhaps even helicoptering and new physical generators and and diesel generators and pumps. that japan has asked of the international atomic energy agency to help the country deal with its nuclear crisis as it comes amid concerns of similar incidents taking place in europe which has many nuclear plants similar to that in a new culture he's accou

situation when i joined by christopher simons an associate professor at the international christian university in tokyo mr simas thank you very much indeed for joining us not so there's been a full explosion of these plans what's the spread of radioactive contamination with reports of radiation a hundred times the annual legal limit of the plant. fortunately we lost mr christopher simons but we do promise to bring him back as soon as we fix this problem right now emergency services remain on high alert and russia's far east region close to northern japan and they say that big danger of the possible radioactive cloud reaching the area is minimal as the wind is expected to blow towards the pacific ocean but despite that some tourists and foreign workers are said to be leaving the area and our correspondent you can think of has more from this one in region that one hundred kilometers north of japan. the emergences ministry say they have reinforced checks of the radiation levels here and say that as of now they stand up less than the average for this area but not residents of this region choose to leave we

lot of financial crises and kyle cleveland a silent killer a psychology professor at temple university in tokyo says the japanese people's preparation and reaction on the ground should be nice them was exemplary. it was pretty compelling i mean this was a quake that was the least two or three minutes and it feeds and just continued a really strong level we were really quite amazed that the level of the forest and they just continue and as i looked out the window i could see the trees and the light pole swaying just probably to the ground kind of dancing i do think of the japan as one of the more of all been advanced countries in terms of preparing for its quakes because they have catastrophic earthquakes the nine hundred twenty three counts of quake. earthquake. and not one thousand nine hundred three and because of that the building codes are a place from one thousand nine hundred nine in particular really strict standards for construction and as a result the buildings are very very stable there's a remarkable lack of structural damage and this entire continent playing region given the level o

cleveland sociology professor temple university in tokyo says the japanese people's preparation and reaction as the ground shook beneath them was exemplary. so there was pretty compelling i mean this was a quote that was the least two or three minutes and then just continued a really strong level and we were really quite amazed that the level of force definitely just continued and as i looked out the window i could see the trees and the light pole swaying just proudly to the ground kind of dancing i do think though that japan is one of the board of all been advanced countries in terms of preparing for its quakes because they catastrophic earthquakes and i think twenty three counts of the code where you know ninety ninety three and because of that the building codes are from nights in eighty nine in particular there really strict standards for construction and as a result the buildings are very very stable there's a remarkable lack of structural damage and this entire contemplating region given the level of this earthquake was a very serious earthquake but in this area we were not actually fl

and cleveland a sociology professor at temple university in tokyo says the japanese people's preparation and the reaction of the ground as the ground truth needs them. it was pretty compelling i mean this was a quake at. least two or three minutes and it just continued it was really strong and we were really quite amazed that. the level of the force and they just continued and as i look out the window i can see the trees and the lights all swinging just partly to the ground kind of dancing i do think though that japan is one of the part of all the advanced countries in terms of preparing for its quakes because they are catastrophic those plates the one nine hundred twenty three consecrates the earthquake in kobe act in one thousand nine hundred ninety three and because of that the building codes are a place from one nine hundred eighty nine down in particular there really strict standards for construction and as a result the buildings are very very stable there's a remarkable lack of structural damage and this entire continent plain region given the level of this earthquake was a very se

very much for it taking out for your time christopher assignments from international christian university in tokyo. again it just to remind you of what's been going on a breaking news at this hour attempt to happen as officials have confirmed the explosion at the if daiichi power plant and it had all see on your screens up white smoke billowing up from the plant at least four people were injured by the extent of the damage is unknown at this time but there are few. years of the possible meltdown and the nuclear safety agency says it's collecting information about the blast it's still unclear where exactly it occurred why and again the extent of the damage is unclear but what we do know some of the information trickling in the roof of the fukushima reactor has collapsed and radioactivity is said to be rising rapidly all residents living within a twenty kilometer radius of the nuclear plant are being evacuated just to remind you about the precautions the government is taking it was a ten kilometer radius now it's extended to a twenty kilometer radius people are asked to evacuate and they are also be

and coal cleveland a sociology professor at temple university in tokyo says the japanese people's preparation and reaction as the ground shook beneath there was some three. it was pretty compelling i mean this was a great but that was the least two or three minutes and it peter just continued to the really strong level and we were really quite amazed that. the level of force and they just continued and as i looked out the window i could see the trees and the light all swaying just. kind of dancing i do think though that japan is one of the boards of all the bands countries in terms of preparing for it works because they catastrophic earthquakes the one nine hundred twenty three counts of quakes like the earthquake occurred back in march one thousand nine hundred three and because of that the building codes are of course from one thousand nine hundred nine on the particular have really strict standards for construction and as a result the buildings are pretty stable and there's a remarkable lack of structural damage and this entire continent playing region team given the level of this earthqua

well christopher simon an associate professor at the international christian university in tokyo says although it may seem like there are many similarities to chernobyl the two incidents are quite different. it looks like this is caused by the cooling system for you and now when the earthquake occurred yesterday at about two forty six the reactors immediately shut down but of course you can't shut down a reactor instantly it has to keep cooling the reaction it's going on inside it so these reactors have backup generators which continue to pump water into that reactor unfortunately the backup generators which are easily generators at some point she might daiichi seem to fail after a vote an hour and they were running on emergency batteries while the military began moving in more equipment more electrical equipment is our the cooling now it seems as though it's possible in the last couple of hours that has failed and the reactor materials that is the uranium in the reactor has been exposed to the air. and there have been reports that he. had died and cesium both radioactive iodine and c

not going to cause in the financial crises call cleveland's a sociology professor at temple university in tokyo he told us the japanese people's preparation and reaction as the ground shook beneath them was exemplary. it was pretty compelling i mean this was a great book that was the least two or three minutes and eight and just continued a really strong level we were really quite amazed that the level of the forest going to date just continue and as i looked out the window i could see the trees and the white ball swaying just partly to the ground kind of dancing i do think of the japan as one of the part of all been advanced countries in terms of preparing projects because they catastrophic earthquakes and i think twenty three counts of quakes we. got ninety ninety three and because of that the building codes are from one thousand a benign in particular have really strict standards for construction and as a result the buildings are very very stable there's a remarkable lack of structural damage and this entire continent playing region even the level of this earthquake was a very serious earthq

well christopher simons an associate professor at the international christian university in tokyo believes the people are now in grave danger of exposure. there is a serious risk of contamination at this point but the contamination is probably limited kind of fukushima area and the authorities are having to focus on the reactors whose temperatures are the highest and that may require divertissement of coolant and cooling materials such as generator power and pump and power away from the other reactors if the level of coolant and the reactor pressure vessel falls below a certain level the tops of those rods will be exposed to the air there is a separate heating of the air and any water vapor around them that causes oxidize ation essentially very rapid rusting which produces hydrogen and that hydrogen is what as we have seen as caused the explosions in reactors the most immediate concern which has come to us in tokyo over the past twelve hours last night is that the amount of fuel available in the north that is gasoline and diesel fuel and diesel fuel is one of the keys to resolving this sit

a consumer market on monday as a visiting professor of international relations i built and university in tokyo plato. very quickly and how. it could equal terms of the. rebels were out there who. were british or on the bulk of term who went home a very very special mission. and we were trying to be for the rise and there's a core been going. on where you are going to be who we want to and remember hope maybe we can all agree. on it in particular we're going to we're going to go. there were when school was closed so let's face it it would be all. operational carrier and so far we haven't seen very normal. meanwhile unrest is spreading further in the arab world at least six people are being killed hundreds with this riot police have sacked anti-government protesters are calling for political reforms and equal rights for the majority shiites. declared a three month state of emergency so deal with protests which are of the country for over thirty days and coming up next hour cross talk guests debate the prospects of a democratic middle east and the possible role of the international community in t

an american university professor in tokyo on business told us the tremors were relentless. >> the shaking got worse and worse. i don't know exactly how long it lasted. it seemed like it went on forever. >> reporter: the country's prime minister, naoto kan, immediately activated an emergency response plan. after the shaking came the warning, and the wave, a chilling preview of the disaster to come. the target, the city of sendai, some 200 miles northeast of tokyo. hundreds are reported missing there. an unbelievable sight, the force of the swirling water sucking boats into its center. reports of at least one vessel missing with 100 people aboard. the tsunami hit with incredible force. the sludge sweeping away everything in its path. this wall of water and mud, some 30 feet high, washed across the low-lying coastal areas. entire towns swept away. thick and brown, strewn with debris. fast-moving, farmlands quickly disappeared. entire major roads, bridges and homes, gone in a matter of minutes. [ speaking foreign language ] >> the airport at sendai was completely destroyed. workers and others

usf has a japanese studies program that partners with universities in kyoto and tokyo. students and professors recorded messages to their counter parts in japan and vowed to help with the recovery however they can. >>> in the south bay, a contentious daw -- debate over water. specifically adding something to it most bay area cities have had for decades, fluoride. more than a million people don't have it and many don't want it. >> san jose is the largest city in america that does not flora date its drinking water. it does for 125,000 residents, but it leaves out more than a million people served by the private san jose water company. that issue brought out more than a hundred people to the water district arguing whether or not to add fluoride. on one side this dentist says 50 years of evidence supports the benefits of fluoride. >> when i practiced in states that had high levels of fluoride, you can see many fewer kids with a whole mouth full of cavities. >> like other cities that draw their water from the sierra, san francisco has had flora dated water since 1972. accord

tokyo. he is one of 27 oregon university foreign exchange students studying abroad in japan. >> i received an e-mail at 4:30 in the morning, japan time. it was the day before yesterday. i was already packing one bag just in case and it said basically to evacuate japan and the spring tournament was canceled. >> this is a photo of john leaving his dorm in tokyo. he wasn't supposed to return home to the u.s. until september. a number of companies are moving their employees out of the radiation zone near the nuclear plant. ikea, h&m clothing, sap and santa clara's applied materials are moving their employees mostly to the southern part of the island nation. bmw has asked its german employees to leave the country. as a result, japan's airport and international terminals are packed. >> the people are really scared, including me. we don't get exact information. >> at san francisco international airport, most on board the japan airlines flight from tokyo are glad to be leaving the country. many describe it as a place and controlled chaos. lisa amin gulezian, abc7 news. >>> rescue crews in japan are n

on average the pas civic plates subducts under japan that work was with colleagues from the university of tokyo. >> rose: professor stein, thank you so much. it's been very, very informative. >> okay. well, it has been my pleasure. >> rose: we'll be right back. stay with us. mr. saakashvili is here, the president of the republic of georgia. in august 2008 georgia and russia fought a brief war over the breakaway region. today rushach and gorge da-- gorge gra-- georgia are in mediated talks over their wantinging to -- >> the issue was eye on joe biden's a-- agenda durings his trip to moscow. i'm pleased to have the president of georgia welcome. >> thank you for inviting me. always nice be back in your studio. >> rose: you once said you wanted for georgia to be a bit of switzerland and a bit of singapore. >> i still insist on that and it has become much more like switzerland and much more of singapore, actually. you know, georgia's transformation from what was a totally failed state with megacorruption, one of the worst places in the world to do business, into what we are now, which accordinging t

>>i was in tokyo on the sixth floor of a university building. >> explain that moment for us. it's something i mean we know of earthquakes here in the bay area obviously. but that was so huge. what was it like? >> we do know of earthquakes here but this was something else. the buildings shook for in excess of three minutes. it took us a half a minute to figure out ok. this was serious. but it shook for three minutes. shook everybody to their core. >> i'm just kind of curious. we're used to these in the bay area. so for the first 30 seconds you realize it's an earthquake. what did you do for the next two and a half minutes up on the sixth floor of the building and it doesn't stop? >> i stood in the doorway just thinking about my son, and hoping i would get back and see him again soon. >> and how did the rest of the building react? did everybody run out or -- >> this is amazing. i was very impressed by the japanese response. there's an enormous calm. nobody was in a panic. there was a lot of faith. i think faith in their level of preparedness. the buildings remained remarkably i

tokyo it goes r.t. so i mean time professor keith ross from the university of some food in the u.k. says that although flooding has hampered efforts at the plant there are other methods that can be employed. the problems of insult water out of the us chris the difficulty is remember that. there are good movie opportunities for bringing in road transport stop and see they have had some power and that they must be the ones on such a ready and they have problems with these accounts and so forth it's into being the successions of problems true to their standard equipment having to trust. you don't want to get in you need oil this is surprising to me i hear are dropping more from helicopters apparently being abandoned i don't know why that. would seem to be a way of getting water through the fuel. and the russian president dmitri medvedev has made his input he says that although incidents in japan have caused concerns of a nuclear energy and show that atomic power is safe if handled properly to just now there is a great deal of attention to the newly built nuclear power stations in the w

and american university professor in tokyo on business, told us the tremors were relentless. >> the shaking got worse and worse. i don't know exactly how long it lasted. it seemed like it went on forever. >> reporter: the country's prime minister, innaoto kan, immediaty issued an emergency response plan. after the shaking came the warning and the wave. a chilling preview of the disaster to come. the target? the city of sendai. hundreds reported missing there. and unbelievable sight. the force of the swirling water sucking boats into its center. one vessel missing with 100 people aboard. the tsunami hit with incredible force. the sludge taking away everything in its past. this wall of water and mud some 30 feet high washed along the low-lying coastal areas. entire towns swept away. thick and brown, strewn with debris. fast moving, farmland quickly disappeared. entire major roads. bridges and homes. gone in a matter of minutes. the airport at sendai was completely destroyed. workers and others scrambled onto rooftops to try and stay above the mud. a huge file in an oil refinery near tokyo con

university students heading back home. some of them ordered to come back home. families wanting people to come back home. what is the mood in tokyo as far as businesses? people working there or perhaps based here in the united states are people leaving? are people staying? how do they feel about what is going on? caller: pam, i have been talking to a lot of people the realtives and friends that -- the relatives and friends that have been working here. there are some people saying absolutely get out. i spoke to a pilot today that said his wife and children left the country as most of his colleague's families. and you have people that are saying no i have confidence that the japanese government is going to be able to solve this problem or at least contain it. we're not afraid. we will stay. certainly though there have been some countries i understand france and other countries that have decided to try and issue warnings pull people out, tell people not to come here for unnecessary reasons travel. and so i think that the big unknown here is what will happen with that nuclear power plant. that is something which is difficult to predi

university thank you very much. now russia is closely monitoring the radiation on its territory nearest to japan well moscow also says it is ready to help tokyo but russia having vast experience in dealing with both natural and manmade disasters. explains. prime minister putin has russia is ready to send few undoubled gas supplies to japan of course energy's very much needed in the shattered country right now as it has lost a lot over its resources electricity is down in many parts of japan as well forty two units of hardware including seven jets are ready to fly to japan together with two hundred doctors and rescuers russia isn't on forty five nations world's voice on stands by to send its help to japan however so far japan has accepted help from six countries only and those are united states great britain and germany new zealand as trail here and south korea meanwhile in the russian capital people are bringing flowers do the japanese embassy laying them by the embassies rules and the country's authorities are of course looking eastwards as well but we need to continue monitoring the situation in the russian far east as closely as possible i

tokyo. thank you very much. we have two experts on nuclear safety tonight. in washington, james acton with the carnegie endowment and joining me here in new york is cham dallas, a university of georgia professor and cbs news nuclear safety consultant. james acton, how serious do you think the situation is right now in japan? >> well, katie, it's clearly deteriorated in the last 24 hours. the explosion inside the containment reactor unit two is significant, and the fire in the spent fuel pool of reactor number four is significant. both of these events have created new pathways for release of radioactivity into the environment, but what i think is important to emphasize is that the possibility of a catastrophic release of radiation equivalent to chernobyl is still very low. >> couric: james, how long do officials have to get this situation under control in your view? >> very, very hard to put any kind of time estimate on it. i mean, we have effectively no experience managing this kind of accident before. i mean, you know, one of the issues is that it's clear a lot of the instrumentation, a lot of the measuring gauges and devices inside of the reactors are at the best untrus