Follow-up to: Pressure doubles inside Reactor No. 2 containment vessel since start of April — Tepco making effort to reduce pressure
Hydrogen Density of Reactor No. 2′s Primary Containment Vessel
Apr. 27, 2012 @ .36% Apr. 11, 2012 @ .19% Mar. 11, 2012 @ .06% Feb. 3, 2012 @ .04% Dec. 22, 2011 @ . . . → Read More: Highest hydrogen levels of year inside Reactor No. 2 containment vessel
Follow-up to: Pressure doubles inside Reactor No. 2 containment vessel since start of April — Tepco making effort to reduce pressure NYTimes: Core damage at No. 2 worse than thought? Reactor water could be flowing directly into ocean or under plant — Risk of fuel melting again, says nuclear engineering professor
h/t Fukushima Diary
Reactor No. 2
April 24, 2012: 7,000,000 becquerels per hour (Bq/h)
March 24, 2012: 1,000,000 Bq/h
Title: Land water flooding reactors to be divertedSource: KyodoDate: Apr. 24, 2012 [...] The Fukushima plant generates large volumes of highly radioactive water on a daily basis because it must perpetually cool melted fuel in reactors that are riddled with meltdown holes, as well as the spent-fuel pools sitting on top of them. Since . . . → Read More: Kyodo: Fukushima Daiichi reactors are “riddled with meltdown holes”
Via April 24 Tepco Handout:
At 11:59 am, because the tendency of pressure increase in the Primary Containment Vessel, we adjusted the exhaust gas flow of the PCV gas control system from approx. 17 m3/h to approx. 38 m3/h in order to decrease the pressure of PCV.
Pressure at 38.64 kPa g on April . . . → Read More: Pressure doubles inside Reactor No. 2 containment vessel since start of April — Tepco making effort to reduce pressure
Follow-up to: Japan Times on Melt Through: “Molten ‘lava’ melted bottom of containment vessel,” says nuclear engineer given access by top official — Huge amounts of fission materials released into environment More from Lead Investigator: “The ‘nuclear lava’ melted the bottom of the containment vessel, leaking a huge amount of fission gasses and particles . . . → Read More: Fukushima Investigation: “Within one day complete meltdown and melt through occurred” — “There is no way that gov’t did not know this” (VIDEO)
Title: TEPCO says no water leaks found at No.2 reactor Source: NHK Date: Wednesday, April 18, 2012 20:56 +0900 (JST)
The operator of the Fukushima Daiichi nuclear plant says inspections using a robot have yet to find serious damage or water leaks at the facility’s No. 2 reactor. [...]
TEPCO said the robot found . . . → Read More: NHK: Tepco can’t find holes at Reactor No. 2 — Nuclear Expert: It’s leaking like a sieve — “No one knows how they’re ever going to remove fuel in my lifetime” — Likely 50, 60, 70 years — Radiation like outer space (VIDEO)
Title: Another thermometer breaks at FukushimaSource: KyodoDate: April 15, 2012 One of the two remaining thermometers at the bottom of the pressure vessel of reactor No. 2 at the Fukushima power plant is broken, Tokyo Electric Power Co. said Sunday. [...]
Tepco said that the sensor’s reading instantaneously jumped 6 degrees to hit 60 . . . → Read More: Tepco: Another thermometer breaks at Fukushima — Now only one left at bottom of Reactor No. 2 pressure vessel
Title: Nitrogen injection temporarily stops at Fukushima Daiichi reactorsSource: KyodoDate: April 13, 2012 Tokyo Electric Power Co. said the injection of nitrogen gas into three nuclear reactor containers [...] stopped temporarily after 1 a.m. Friday.
The company has continued injecting nitrogen gas into the containers of Nos. 1, 2 and 3 reactors to prevent . . . → Read More: Kyodo: Nitrogen injections stopped for fourth time in recent weeks
Follow-up to: *NEW* Goddard’s Journal: Did Fukushima Unit 3 Fuel Pool Explode? (VIDEO)
The most recent analysis by Goddard’s Journal indicates a steam explosion took place at Fukushima Daiichi Reactor No. 3.
In the days after March 11, the NRC discussed the possibility of steam explosion(s) at Fukushima.
NRC’s possible worst case scenario: Examined . . . → Read More: Goddard’s Journal analysis indicates steam explosion at Reactor No. 3 — NRC discussed steam explosion ejecting entire core (VIDEOS)
Title: 120402j0101.pdf (Japanese-only) Source: Tepco Date: April 2, 2012
A reader writes in describing the contents:
Report to NISA on units 1 ~ 3 thermometer reliability (the NISA requested Tepco to write a report once a month):
Some of the thermometers not previously evaluated were found to be usable, and some were found . . . → Read More: Over 100°C? New Tepco data shows temperature spiked at two gauges in Reactor No. 2 — Similar rise patterns for both charts
Title: Water levels low in Fukushima reactorSource: UPIDate: March. 29, 2012 at 4:43 PM Water levels in at least one reactor at Japan’s Fukushima nuclear plant are lower than estimated, putting it at risk of a new meltdown, the plant operator said.
The report, the result of an internal investigation by Tokyo Electric Power . . . → Read More: UPI: Fukushima at risk of a new meltdown — Level of cooling water 29 feet lower than estimated
Title: A scenario of large amount of radioactive materials discharge to the air from the Unit 2 reactor in the Fukushima Daiichi NPP accident Source: Journal of Nuclear Science and Technology – Volume 49, Issue 4 Author: Fumiya Tanabea Date Published: 28 Mar 2012
Abstract Based on an analysis of the measured data with . . . → Read More: New Analysis: Large amount of radioactive materials had discharged through breach in primary containment at Reactor No. 2
Title: Still critical: radiation levels at Fukushima can kill in minutes Source: The Independent Author: David McNeill Date: March 28, 2012
[...] Critics say the fresh findings illustrate the still precarious state of the complex. “The problem for Tepco is that the damage is so severe to the base of the reactor, and the . . . → Read More: Nuclear Consultant: Damage to base of Reactor No. 2 is ‘so severe’
Title: Latest Fukushima probe appals expertsSource: EuronewsDate: March 28, 2012 [...] reactor number two showed damage so severe special technology will need to be developed just to survive the harsh environment. Cleaning up is going to take decades.
Water levels inside the containment vessel that houses the radioactive core were also found to be . . . → Read More: TV: Radiation levels 10 times higher than experts hoped at Reactor No. 2 — No. 1 and 3 even worse (VIDEO)
Follow-up to: Kyodo hints Tepco’s long-term plan to decommission Fukushima may be in jeopardy
Title: High radiation means delays in decommissioning crippled Fukushima reactors Source: AJW by The Asahi Shimbun Author: HIDENORI TSUBOYA Date: March 28, 2012
High radiation means delays in decommissioning crippled Fukushima reactors The decommissioning process at the Fukushima No. 1 . . . → Read More: Asahi: High radiation means delays in decommissioning Fukushima Daiichi — 30-year roadmap will likely now have to be revised
Title: Lethal radiation detected inside Fukushima reactor Source: NHK Date: Wednesday, March 28, 2012 11:13 +0900 (JST)
Tokyo Electric Power Company has detected extremely high levels of radiation inside one of the crippled reactors of the Fukushima Daiichi nuclear power plant. [...]
It says radiation levels increased as the dosimeter was . . . → Read More: NHK: Suppression chamber “may have been destroyed” at Reactor No. 2 (VIDEO)
Title: Fukushima No. 2 reactor radiation level up to 73 sieverts per hour Source: Kyodo Date: March 28, 2012
The operator of the Fukushima Daiichi nuclear power plant said Tuesday that the radiation dose inside the crippled No. 2 reactor stood at an extremely high level between 31.1 and 72.9 sieverts per hour, underscoring . . . → Read More: Kyodo hints Tepco’s long-term plan to decommission Fukushima may be in jeopardy
Title: Fukushima reactor water level shallower than thoughtSource: The Yomiuri ShimbunDate: Mar. 28, 2012 The water level in the containment vessel of the No. 2 reactor at the Fukushima No. 1 nuclear power plant is only about 60 centimeters deep, far shallower than previously assumed [...]
According to some experts, it is possible that . . . → Read More: *Yomiuri* Experts: Melted fuel may not be covered in water — Far shallower than assumed — Tepco still claiming Fukushima Daiichi in state of ‘cold shutdown’
Title: ‘Fukushima reactor in crisis again’Source: AFP Date: Mar 28, 2012, 05.22AM IST A new probe at Japan’s crippled nuclear power plant has found fatal radiation levels and hardly any cooling water inside one of the reactors, renewing concerns about plant’s stability.
[...] detected radiation levels up to 10 times the fatal dose inside . . . → Read More: AFP Headline: ‘Fukushima reactor in crisis again’ — Renewed concerns about plant’s stability
Title: TEPCO releases video of No. 2 reactor containerSource: NHK Date: March 27, 2012 [...] The water is not as murky as feared, and contains whitish floating matter thought to be peeled paint and rust, not melted nuclear fuel. [...]
The utility also detected extremely high radiation of 72,900 millisieverts per hour [...]
The . . . → Read More: NHK: Whitish floating matter in Reactor No. 2 said to be rust, not melted fuel — No endoscopy for Reactors No. 1 or 3, radiation too high (VIDEO)
Title: New probe finds worse damage at Fukushima reactorSource: The Associated PressDate: 8:41 a.m. Tuesday, March 27, 2012 [Tepco ...] found fatal radiation levels and hardly any cooling water inside one of the reactors, renewing concerns about the plant’s stability.
[Tepco ...] detected radiation levels up to 10 times the fatal dose inside the . . . → Read More: AP: “Hardly any cooling water inside one of the reactors” — Water level only 6% of estimate — Radiation at 10 times fatal dose
Title: Fukushima No. 2 reactor radiation level up to 73 sieverts per hour Source: Kyodo News Date: 20:11 27 March
The operator of the Fukushima Daiichi nuclear power plant said Tuesday that the radiation level inside the crippled No. 2 reactor stood at an extremely high level between 31.1 and 72.9 sieverts per hour, . . . → Read More: 73 sieverts per hour detected at Reactor No. 2 — Measured 4 meters from bottom