Highest hydrogen levels of year inside Reactor No. 2 containment vessel

Published: April 27th, 2012 at 12:13 pm ET


Follow-up to: [intlink id=”pressure-doubles-reactor-2-containment-vessel-start-april-tepco-trying-lower-pressure” type=”post”]{{empty}}[/intlink]

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 @ .45%

For 2012, it appears Tepco did not publish hydrogen levels for the No. 2 PCV until Feb. 3. Please post in comments or send in as a tip if you are able to locate a figure for hydrogen levels between Dec. 23, 2011 and Feb. 2, 2012.

Published: April 27th, 2012 at 12:13 pm ET


Related Posts

  1. Pressure doubles inside Reactor No. 2 containment vessel since start of April — Tepco making effort to reduce pressure April 24, 2012
  2. Report: Reactor No. 2 has multiple 4-inch holes in CONTAINMENT VESSEL May 24, 2011
  3. Mark Your Calendars: Next survey inside Reactor 2 containment vessel set for 2017 January 20, 2012
  4. Hydrogen levels quintuple at Reactor No. 2 in last two weeks March 26, 2012
  5. Asahi: Tepco can’t find where huge amount of highly radioactive water is leaking at Reactor No. 2 — ‘Fractures’ in containment vessel suspected December 12, 2012

15 comments to Highest hydrogen levels of year inside Reactor No. 2 containment vessel

  • many moons

    There is a lot of talk about an earthquake taking down reactor spent fuel pool and all. How likely is it that a hydrogen explosion could bring down 4????

    • Sharp2197 Sharp2197

      Shock wave from a large explosion 50 meters away. Sure wouldn't help.

    • PhilipUpNorth philipupnorth

      many moons: The explosion that demolished the upper floors of Building4 might have been from a zirconium/cesium explosion in SFP4, which at the time contained no water, which had boiled off. The hot spent fuel rods were burning. A mixture of zirconium and cesium vapors is explosive, and this is probably what caused the explosions that blew out the walls.


      The zirconium came from the highly unstable Zircaloy cladding, commonly used in nuke fuel rod cladding. Zirconium is so explosive that it has been used in pyrotechnics. Cesium is a product of nuclear chain reactions, and is present in spent nuclear fuel rods. Zirconium vapors explode in combination with cesium vapors, which would occur as fuel rods heat up durning a meltdown.

      If SFP4 springs a leak, or if Building4 collapses in some future earthquake, a meltdown of the fuel rods may occur once again. And, yes, a zirconium/cesium explosion is once again possible.

      • Sharp2197 Sharp2197

        Thanks for the great info Philip. I think what many moons was asking is, if the hydrogen level in 2 continues to build and 2 has a hydrogen explosion or an explosion that you discribe, would the force of an explosion in 2 cause 4 to topple over.

    • AGreenRoad AGreenRoad

      And when they say hydrogen, dont they really mean the radioactive gas tritium?

      Is there a difference?

      Are they covering their you know what by making it sound safer and non radioactive somehow?

      • AGreenRoad AGreenRoad

        75% US Nuclear Plants Leaking Toxic Tritium Radiation Into Drinking Water Supply; via A Green Road Blog

      • Good question. The answer is that both radioactive tritium and the more common (but very explosive) hydrogen gas are present in the plants. When we hear of the massive hydrogen explosions that rocked Fukushima, the culprit in the explosion itself is the buildup of ordinary hydrogen gas in the presence of air containing oxygen. The majority of the hydrogen would have come from the zirconium-water/steam reaction as the fuel rods melted and burned. In the explosions there certainly would have been harmful tritium released along with the cesiums, strontiums, iodines, and assorted transuranics like plutonium. Of course EVERY nuclear plant releases and leaks liquid and gaseous tritium on an ongoing basis as part of "normal" operation.

        • Sharp2197 Sharp2197

          Back to Many Moons original question, do you think that an explosion, you have described, if it were to occur in reactor number 2, could the shockwave of this event cause number 4 to shatter or collapse?

  • Cindy

    They are still a long way from a hydrogen explosion.. however when they 'vent' it releases lots of radiation, many spikes were recorded

  • glowfus

    so where is #2's core? could a $50 dollar t.l.d. thermometer find it? could being the first to lose a reactor underground (or 14) too emotional to talk about?

  • RutherfordsGhost

    There are many things loose underground at Fukushima.
    Lets face it – the Japanese do not have a handle on the situation.

  • Pallas89juno Pallas89juno

    The problem is NOT Hydrogen explosions, but small and inefficient prompt criticality related NUCLEAR explosions in the substrate bedrock under the plants, which have likely occurred repeatedly since March, 2011. Small, inefficient (leaving the corium to re-settle) nuclear explosions from large totally improperly contained high mass blobs of corium might produce quakes in the range of 2.5 through 5.0 (lower or higher, as well) and there probably have been quite a number of these within distances that might be plausible for escaped corium under and adjacent to FukuDai. I know and have had classes from scientists at the USGS in Palo Alto, CA and there are many people there with great integrity. However, that does not mean that depths of small earthquake epicenters are being accurately reported to the public. All data dissemination to the public must be scrutinized for accuracy against both common sense and against other data and sources. The problem is not Hydrogen explosions, but the radiation, and fallout spewing from fissures in the ground coming up through the original corium melt-through holes, as well as from cracks in the ground in and around FukuDai. For all we know and are not being told, there may be marine locations where intensely radioactive groundwater is mixing with seawater from very likely ongoing fission events or small nuclear explosions from all three coriums. Some recent measurements in coastal currents would appear to support such a statement.

  • hbjon hbjon

    Where you have heavy water that has been irradiated, you will find some tritium. Under special conditions tritium will undergo a fusion reaction. There is your hydrogen explosion. I am no physicist, just a dump truck driver, but I think it goes something like 3H plus 1N = He + energy. But, there isn't any heavy water anymore. Remember, heavy water is a substance they use to shield radiation.