Guest post by reader Sebtal
Introduction – Sebtal is a commenter to Nextbigfuture and has provided researched information. Sebtal felt that the Union of Concerned Scientists, who are a group that are against nuclear power had done a good job covering the Fukushima Daiichi nuclear plant. I am presenting Sebastian selected Fukushima Daiichi coverage from the Union of Concerned Scientists. The Union of Concerned Scientists is a $20 million a year organization with a primary focus of being a watchdog on nuclear power and nuclear weapons issues.
A comparison by time of NBF posts vs. Allthings nuclear on Fukushima Daiichi.
Detailed description of the problems occuring and consequences. Information includes particular systems that failed, direct cause (blackout), power ratings of the reactor (that provide proxy information to calculate cooling levels required in post shut down phase), information about potential consequences and time frames for failure of cooling.
Discussion of pressure rises in the containment, with reference to the particular systems and explanation of the mechanisms in play. Possible need to vent containment structures raised, and the potential for radiation release is discussed. It is not alarmist: “If there has been no appreciable reactor core damage, the air vented from containment will contain minute but detectable amounts of radiation. The filtration systems are designed to lower that radioactivity release by nearly a factor of 100.”
A press release on bleed and feed. Technical information on reactor pressure provided, not much wider context of the situation.
NBF reposts FEPEC status update.
NBF repeats the IAEA rating of Fukushima Daiichi is a 4 on the INES scale, claims no core meltdown, though the amount of time the fuel rods had at this point have known to be exposed indicates that some degree of melting is likely.
NBF Note : the IAEA ranking of the incident at Fukushima Daiichi was accurately assessed as a INES 4 at that point in time. It would later be raised to an INES 5 and probably an INES 6.
UCS writes an update on the Fukushima reactor. Initial reports that the hydrogen explosion in unit 1 took place in the turbine hall are rejected. An alternative explanation is outlined with reference to a diagram of the plant and containment structures. Implications for the reactor core are discussed. Interpretations of the detection of isotopes outside the plant are discussed: “Thus, contrary to some news reports, the detection of cesium outside the reactor does not necessarily indicate that the primary containment has been breached.”
“The cooling systems for the Unit 1 reactor have not been operating and, as the core heats up, the water surrounding the fuel has evaporated to the point where the fuel becomes exposed to the air. Unless there is a way to replace the water the fuel will continue to heat up.
To attempt to cool the reactor, TEPCO has been pumping sea water into the reactor vessel. Since this is very corrosive and will seriously damage the reactor, this is an option of last resort and indicates that they do not expect to get the cooling systems back online.
Reports note that boric acid is being added with the sea water. Boric acid is a soluable form of boron, which is very good at absorbing neutrons. By adding this to the water around the fuel rods, it would capture neutrons that could otherwise cause additional atoms to fission. This is being added to the reactor to make sure it does not become critical again, which might happen in two ways: (1) fuel rod damage that results in fuel rod segments dropping to the bottom of the reactor vessel, where they could form a critical mass, or (2) withdrawals of the control rods caused by malfunctions of the hydraulic control units that move the control rods in and out of the core.
Recent reports state TEPCO has succeeded in filling the reactor vessel with water, which would mean the fuel rods are no longer exposed to air. But some form of cooling will still be required.”
More discussion giving details about water levels etc.
Impact of MOX discussed:
I have done considerable analysis on the safety risks associated with using MOX fuel in light-water reactors. The use of MOX generally increases the consequences of severe accidents in which large amounts of radioactive gas and aerosol are released compared to the same accident in a reactor using non-MOX fuel, because MOX fuel contains greater amounts of plutonium and other actinides, such as americium and curium, which have high radio-toxicities.
Because of this, the number of latent cancer fatalities resulting from an accident could increase by as much as a factor of five for a full core of MOX fuel compared to the same accident with no MOX. Fortunately, as noted above, the fraction of the fuel in this reactor that is MOX is small. Even so, I would estimate this could cause a roughly 10% increase in latent cancer fatalities if there were a severe accident with core melt and containment breach, which has not happened at this point and hopefully will not.”
NBF Note – severe core melt and containment breach has not happened
Design flaws of MK1 containment are mentioned:
“The Sandia report characterizes these probabilities as “quite high.” It’s not straightforward to interpret these results in the context of the very complicated and uncertain situation at Fukushima. But they are a clear indication of a worrisome vulnerability of the Mark I containment should the core completely melt and escape the reactor vessel.”
Reactor core cooling discussed, cooling requirements for reaching steady state are estimated.
NBF posts following article
Articles contents are similar to UCS articles from the 11th and 13th, but includes some errors regarding venting procedure, namely the deliberate venting into the building structure (full disclosure, I took this for granted also) and thereby implicate the hydrogen explosion as plant operator error rather than a design error. It is worth noting that the UCS blog had correctly identified the procedure for this plant some days prior.
This may have led to the erroneous conclusion:
“The plant is safe now and will stay safe.
“Japan is looking at an INES Level 4 Accident: Nuclear accident with local consequences. That is bad for the company that owns the plant, but not for anyone else.
* Some radiation was released when the pressure vessel was vented. All radioactive isotopes from the activated steam have gone (decayed). A very small amount of Cesium was released, as well as Iodine. If you were sitting on top of the plants’ chimney when they were venting, you should probably give up smoking to return to your former life expectancy. The Cesium and Iodine isotopes were carried out to the sea and will never be seen again.
* There was some limited damage to the first containment. That means that some amounts of radioactive Cesium and Iodine will also be released into the cooling water, but no Uranium or other nasty stuff (the Uranium oxide does not “dissolve” in the water). There are facilities for treating the cooling water inside the third containment. The radioactive Cesium and Iodine will be removed there and eventually stored as radioactive waste in terminal storage.”
So, the first four days. The technical information on allthingsnuclear is accurate, detailed, quantative and can not possibly described as alarmist. NBF has primarily reposted FEPC status updates, and a couple of in depth articles that while ok, are well on the optimistic side, and is posting premature damage limiting in assigning INES categorization and radiation measurements in bananas.
NBF will later make a comparison of over-estimates and under-estimates that will primarily focuses on the rantings of a reputedly well known pediatrician’s opinion on the matter.
I did not assign INES rankings. I reported the INES rankings from official sources. Radiation measurement charts and radiation in nature (such as bananas) were all factually accurate. There was and is a lot of hysteria and inaccurate reporting on the effects of radiation at different levels.
The Over-estimate / underestimate article of March 27 talked about the over estimates of EU energy chief Oettinger who said that the Fukushima was an apocalypse and that Japan was in the hands of god because of Fukushima. This caused the stock and treasury and commodity markets to get hit. Causing tens of billions of dollars in losses for people who had to sell that day. He was rebuked by the French government. There is no mention of Caldicott (an australian doctor who is an anti-nuclear leader).
On April 2nd there was a mention of Helen Caldicott and the George Monbiot debate in the Carnival of Nuclear Energy 46 from an article submitted by Atomic Insights blog. A Carnival of blogs is where a host blog (nextbigfuture in this case) publishes articles from other blogs from that week.
Caldicott is not mentioned until April 2nd (5 days after the over estimate / under estimate article. Caldicott – Sebtal is in denial about her fame and her influence. She is not reputedly well known. She is well known. In an Oscar winning documentary film in 1980s. On TV around the world, has her own radio program, has several well selling books and had respectable attempts at running for office in australia. Started and ran for 5 years the anti-nuclear physicians organization (up to 26000 members). Sebtal finds Caldicott embarassing as a spokesperson for some of his views on non-proliferation and for greater nuclear power safety measures. Sebtal also does not like to compare the dangers of coal, oil and natural gas with nuclear power because he thinks it dilutes the need for improving nuclear safety when it is pointed out that coal, oil and natural gas are tens to thousands of times more dangerous.