Updated advice on Japan from Government Chief Scientific Adviser to UK Ambassador
This was published under the 2010 to 2015 Conservative and Liberal Democrat coalition government
Sir John Beddington, Government Chief Scientific Adviser, spoke to Her Majesty's Ambassador to Japan David Warren on 25 March with an update on the situation in Japan.
Transcript of phone call (16.00 hours local time) 25 March.
[Ambassador David Warren: DW] John, would you like to start by giving us your assessment of the current situation and then perhaps people can ask questions.
[Sir John Beddington: JB] Yes, of course. Just to say that we also have a colleague from the Health Protection Agency, Jill Mearer phoning in and Hilary Walker from the Department of Health is here. Both of those will be able to complement anything I’m going to be saying, Just to update people, we had a meeting of the Scientific Advisory Group in Emergencies yesterday. What I would like to focus on first of all is the reactor situation, then I’ll start with some comments on water and food.
So in terms of the situation at the plant, clearly it is still extremely serious. But I think it is fair to say that the Japanese authorities are making some progress. The evidence we are getting, in terms of reactors 5 and 6 is that they seem to be in safe cold shut down and for the moment appear to pose no threat. When we did the analysis before, in the very worst of all cases we were thinking about a number of individual reactors and the ponds releasing radioactivity. We really think that the extreme, extreme worst case is now less likely. There is still cause for concern but there are real indications that there is some progress.
There are a couple of things that we are particularly pleased about. The first is that in some of the reactors the Japanese are starting to substitute sea water with fresh water. That is going to help because with sea water there is a tendency for salt deposits to build up. So the fact that they are moving to fresh water is good news. The restoration of power is clearly good news because they can do an awful lot more, however, slow and careful work will be needed to actually reconnect services to the power. And you will have seen reports of steam releases and smoke and so on. The thing is that they can be worrying to look at, but the authorities are monitoring all the radiation levels. If there was significant radiation associated with the smoke coming out that would be detected quite quickly. So in terms of the general situation for the plant, it is steady progress. By no means can we forget about it now and say it is all over. It is still a very serious situation. But there is definitely an improvement over the last few days. So it is cautious good news but we’re very much not out of the woods yet.
[DW] I want to give everyone the chance to ask questions. And I guess what is uppermost in some people’s minds will be the food and water contamination given the reports 2 days ago about a higher than normal levels, for babies, of iodine in tap water and of food contamination in products coming out of the affected prefectures. Can I ask you to cover that before we take some questions?
[JB] Let me take water first and I will ask Hilary Walker [Health Protection Agency] and JM to comment. First of all, we think that the advice being given by the Japanese authorities is extremely sensible: We would recommend that advice is followed. The other thing I would comment on is that radiation levels that the Japanese use in developing their recommendations are more cautious that the ones we have in the UK or Europe more generally. In terms of the mains water supply as was reported on 23rd March, it is pretty much safe to drink for all age groups for a short period. In terms of consumption of water, babies should avoid it. I think I’ll pass to Hilary for her comments on that.
[Hilary Walker: HW] As John was saying, the Japanese recommendations are much more cautious than ours. You must remember that these levels are based on assumptions of consumption over quite a long period of time.
[JB] Yes, this is just a one-off occasion. An explanation for it will be sought, but at the moment the recommendations from the Japanese seem completely sensible. Just to add to that it is completely safe for washing. You don’t have to go and buy bottled water to bathe your children in.
The other thing I’d like to say in terms of water is around the stable iodine tablets. There is absolutely no point in taking them at the moment. They only last for 24 hours. The only situation in which you need to be thinking about taking them is if their advice is that a radioactive plume is moving over in a few hours. Don’t take them at the moment because there is absolutely no point whatsoever.
That concludes the things on water. The sort of concentrations that we’re seeing mean the recommendations by the Japanese authorities were entirely precautionary and sensible. I would just like to ask Jill Mearer [Department of Health] to comment.
[JM] I would like to say that levels that were found were below any where we would be making recommendations in the UK not to drink water. They are more precautionary than the UK. If we had these levels in the UK we would not be advising people not to drink the water. Also, we must remember that the doses that we use to define these levels are based on 2 whole months of consumption. Now there are things happening in Japan and increased levels of radioactivity occasionally found in food and water. But you can see yourself that the Japanese authorities seem to get on to deal with them within a matter of hours. And there was only one day when the advice was for babies to not drink water. So again you have got a big level of precaution there. It seems completely unlikely that something would go amiss for 2 months when the authorities are being so vigilant.
[JB] Let me move on to food, then. We talked about food in the past and my advice remains unchanged. Avoid all food from the affected area. The accumulation of radioactivity that has actually spread from the plant, and the amount of that radiation in the food in that immediate area, is going to be monitored. But the basic thing is to avoid food from around that area. In the case of the marine environment, you should avoid seafood, in particular shellfish and seaweed. These are organisms that will accumulate higher levels of radioactivity. Fish don’t accumulate so much, but generally anything from the affected area should be avoided. Draft guidelines for the control of seafood [by the Japanese authorities] have been looked at by the UK authorities, the Food Standards Agency and DEFRA in particular, and they agree that they seem sensible and proportionate.
The situation on food is obviously going to be changing. But I think the key thing is to avoid food produced in that area. I am sure the labelling will tell you if the food is from a particular area, but if you are in doubt, don’t eat it as a sensible precaution. There will be an issue of longer-term contamination. This is not going to go away in a few weeks. There will be a genuine issue of long-term contamination in the area, in products of both food and seafood from there, but that is for the future. At the moment avoid anything from the area.
[JM] It is very easy to monitor for the type of radiation that is around in the environment. It’s not a difficult task, at all. And that again helps the Japanese in their role of regulating it all.
[Q] What would be the trigger for the Travel Advice level to be lowered for British nationals in Tokyo?
[JB] As we have indicated before in our conversations, the Travel Advice is not predicated on radiation issues alone. It’s to do with the general disruption and the difficulties of living in what is obviously a very disturbed place at the moment. As we have previously been saying, there is no reason from the point of view of radioactivity why you should not be able to continue to live quite happily in Tokyo
[Q] You talk about not eating food from the affected area. But I assume you are talking about a larger area than the 80km limit. So how large an area are you talking about?
[JB] In terms of the area, I think that has to be monitored by the Japanese authorities, and the advice they give will be the appropriate one. They are taking highly precautionary levels here and it seems to us that that is sensible. We can’t follow everything from here. The Japanese are monitoring on the ground and their advice will be that which we strongly suggest you follow. As Jill and Hilary have emphasised too, the radiation levels that the Japanese are using are really quite stringent. In the case of water, the advice you are getting from the Japanese authorities is highly precautionary in the context of the sort of concerns we would have in the UK and Europe. The levels of radiation that they are advising people to refrain from drinking water, babies in particular, are significantly lower than the UK and Europe.
[JM] If I can add to that, when we model these things in the UK we usually find that the food bans have to go further than where they are evacuating and sheltering people. And that may well be the same in the long term. But we would leave it to the Japanese authorities to look at the food against their established regulations. The area may be wider than the current shelter and evacuation area.
[JB] Jill has made a good point. We are not just talking about the 30km but a significant area around the plant. Because you get wind changes and rainfall. All that will be deposited on plant material and water, and radioactive seawater will be flushed out from the plant. So it will be significantly wider than the 30km. Quite how wide will have to be determined from monitoring by the Japanese.
[Q] Can you please clarify your comments on boiling water which were inaudible earlier due to static?
[JM]. The radioactivity levels are really very low. This is a one-off, isolated event and radiation levels are now way back down. The other thing that I would say is that the reason for boiling water is not to eliminate radiation, but a safeguard against contamination by bacteria and viruses. With the disruption that has been seen in Japan, there may be danger of some contamination of water by bacterial and viral products.
The only other thing to say is that we have been very worried by what has been happening in Fukushima. But there has not been a massive release of radiation in the area, so that contamination of food stuffs is properly and sensibly precautionary. If there were a substantial release - and we have not seen one yet, as I’m talking about the meltdown of a reactor or something like that - in that situation the food advice would have to be seriously considered. But the Japanese seem to be doing it in a perfectly sensible way from our perspective.
[JB] There has of course been some radioactivity getting out beyond the plant. However, I concur with Jill’s comments.
[Q] Have all the recent events at the reactors, including the radiation injuries suffered by the workers, been taken into account in your calculations? Or are you still getting new information for your analysis?
[JB] We are modelling the situation as soon as we get information. This is not just the UK but international authorities as well. What is not clear at the moment is the contamination of water in Unit 3. Whether that is some problem with the reactor itself or with the pool for spent fuel rods. But certainly in assessing the worst case scenarios we are taking pessimistic assumptions. So we are modelling the situation as if there were a reactor meltdown, an explosion and a release of radioactivity, and an associated release from ponds. The worst, worst situation, as I said last time, would be if all ponds and all reactors started to produce radioactive material into the atmosphere in a very short time. We just don’t think that is now even a reasonable worst-case scenario. We think it is extreme. We are taking into account the up-to-date information but we are still taking a precautionary view. We are monitoring the situation and updating our analysis on a real-time basis so that every 3 or 4 hours, as weather changes, we re-do our calculations.
[Q] We assume that some natural cooling of the reactors and rods has been happening in the two weeks since the crisis began. How is that affecting the outlook for the next few weeks?
[JB] You are right. I do not want to sound too optimistic, but as every day passes without a major incident the radioactivity will be dropping through natural processes. And so the amount of energy and heat produced will be dropping over time. But when people asked me a while back how long this might go on, I had to say that we cannot relax. This is going to be a matter of weeks. And I think in terms of the issues to do with the contamination of food in the area, this is going to be significantly longer. In terms of clean-up, we are thinking in terms of several years before the plant can be properly dealt with.
[JM] In terms of cleaning up the agricultural land, the rate at which you can clean it up it depends on the fertility of the soil. In areas that are poorly fertile it might take a while. But if you have got a large agricultural area with very fertile soil it can be done reasonably quickly, but we may still be talking years rather than days or months.
[Q] In relation to the water contamination in Tokyo, we had a spike the other day that followed a period of rain. Can we anticipate more spikes after rain showers?
[JB] The straight answer to that is I don’t know. We were puzzled by the spike. We don’t have a ready explanation for it. What I would use as a guide is the constant monitoring that the Japanese are doing of the radioactive levels in their various water treatment plants, and they will tell you as soon as there are measurements. I don’t think that rain is going to be a sensible guide for you. Use the direct measurements on water plant radiation. The Japanese will certainly be able to provide advice.
[Q] Someone mentioned that the Iodine 101 levels in water reported are safe for two months. I wonder whether for young children there is a total, say over a year, which you would be happy or unhappy with?
[HW] The reason why we measure it for two months is because the iodine decays.
[JM] I don’t have figures safe for a year, but given the radioactive decay of the iodine since the reactors shut off as soon as the earthquake hit, the iodine becomes less and less of a problem as radioactive decay happens. So two months is the equivalent of forever for a non-operating reactor
[JB] That’s a very good point. The delay is very fast. So we think that two months is a perfectly sensible basis for it. Obviously this is being monitored. But by and large the levels that you are seeing in the water supply at the moment are not a concern.
[Q] I understand that the risks are low in Tokyo, but what about those of us living close to the reactor. Is there any precautionary advice we should be aware of?
[JB] For those of you nearer to Fukushima there is an issue of timing. Taking of stable iodine tablets can be both directly before a radioactive plume moves over, or after. And the efficacy is quite strong. The key thing in the case of anything happening, such as a meltdown, is to stay indoors and take the stable iodine, even within a few minutes. I will ask Hilary to expand on that.
[HW] The key thing that we need to say is follow the advice of the Japanese authorities because they will very rapidly be aware of the things that are going on. If you are closer to the plant you should shelter and take the stable iodine, and follow the instructions of the authorities.
[JB] Don’t take it now. It only lasts for 24 hours. Save it and if something does happen, radiation is released, that will be announced. That is the time to take it. It needs to be taken very close to the exposure to radioactivity. If you are living a lot closer than Tokyo, and the prevailing wind is in your direction, the radioactive plume will arrive sooner than it would in Tokyo. The direction of the prevailing wind is monitored on an ongoing basis.
[Q] We have talked about iodine in water. What about caesium?
[JM] The authorities will be measuring for caesium but presumably in this case the trigger was the level related to iodine. Caesium does have a longer half-life and will end up being the prevailing agricultural problem in the long term.
[JB] We have seen no indication of levels of radioactive caesium beyond negligible in water. But caesium is a problem in terms of vegetation and that is why I can say that for agricultural products in the area we have got to be thinking in terms of months at the very least.
I would like to close by emphasising that if it would be helpful if the situation changes, we would be happy to do this again. We in the UK are meeting regularly and monitoring the situation and are happy to provide advice as things develop.