Japan Earthquake: Nuclear Plants at Fukushima Daiichi

[razzz]

Watched bot adventures in Unit 3 1st floor, lots of blown covers on electrical boxes. Looks like pressure found its way to conduits that carry the electrical cables and traveled until hitting something like access panel then blew them off the cabinets.

Last I saw, one bot was trying to remove a ladder hung up on a blast door...

 

[PietKuip]

I've not seen any very recent fallout data. Winds blew inland on Sunday and Tuesday, 19th April and there was rain. The plume forecast at http://www.zamg.ac.at/pict/wetter/sonderwetter/fuku/20110419_I-131_FUKU.gif was not too healthy.

Live data on the radiative dose is at http://atmc.jp/

(In Japanese, but you can read the graphs: some small blips on April 19th. Deposition data will certainly show clearer spikes.)

 

[PietKuip]

Does anyone know the definition of "daily deposition" as mentioned in http://www.slideshare.net/iaea/radiological-monitoring-and-consequences-19-april-2011 ? Is it the difference of the measured radioactivity from soil samples between that day and the day before ? How do "daily depositions" and "gamma dose rates" relate with each other ?

Deposition is probably measured by some plastic sampling film. A new clean sheet every day, of which the activity is then determined by gamma spectroscopy (to get all the different nuclides).

Gamma dose rates can be measured by geiger counters etcetera.

 

[ascot317]

You can download all 23 videos from Tepco. http://www.tepco.co.jp/en/news/110311/"

Yeah, saw that later. A lot of snippets, as if taken from a cellphone.
It looks like taken from a HD-cam though, just rendered to a lower resolution.
I take back my earlier assessment, it's doesn't look like a bad student project, rather like something from high school.

Watched bot adventures in Unit 3 1st floor, lots of blown covers on electrical boxes. Looks like pressure found its way to conduits that carry the electrical cables and traveled until hitting something like access panel then blew them off the cabinets.

Last I saw, one bot was trying to remove a ladder hung up on a blast door...

"Adventures", I like that. Fukushima will offer a good basis for video games, just like Chernobyl. Regarding the blown-off covers, don't forget the quakes.

I was wondering about the ladder. It looks like as if someone put it there on purpose. The door appears to be open.

 

[flyingblind]

Yeah, saw that later. A lot of snippets, as if taken from a cellphone.
It looks like taken from a HD-cam though, just rendered to a lower resolution.
I take back my earlier assessment, it's doesn't look like a bad student project, rather like something from high school.



"Adventures", I like that. Fukushima will offer a good basis for video games, just like Chernobyl. Regarding the blown-off covers, don't forget the quakes.

I was wondering about the ladder. It looks like as if someone put it there on purpose.

I think it is part of the ceiling. Like a drop ceiling.. No pun intended. ;-)

 

[razzz]

I was wondering about the ladder. It looks like as if someone put it there on purpose.

You are going to see a lot of strange things as time goes on. This is like the House of Horrors in four different versions.

There were some readings but I am not sophisticated enough to understand them, not sure I want to know.

 

[ascot317]

You are going to see a lot of strange things as time goes on. This is like the House of Horrors in four different versions.

That's why I'd like to see the KHG bots in there, they have 3d-laser-sensors and more sophisticated handling tools. Or, for starters, a HD cam on a looong stick held into the upper floor of the reactor buildings.

I think it is part of the ceiling. Like a drop ceiling.. No pun intended. ;-)

Maybe. But look at its feet.

 

[elektrownik]

That's why I'd like to see the KHG bots in there, they have 3d-laser-sensors and more sophisticated handling tools. Or, for starters, a HD cam on a looong stick held into the upper floor of the reactor buildings.
Maybe. But look at its feet.

It is ladder on 100%

 

[flyingblind]

That's why I'd like to see the KHG bots in there, they have 3d-laser-sensors and more sophisticated handling tools. Or, for starters, a HD cam on a looong stick held into the upper floor of the reactor buildings.




Maybe. But look at its feet.

Yeah very possible now that I look closer..
Here is the vid from the tepco site http://www.tepco.co.jp/en/news/110311/images/110420_1f_23.zip"

 

[MadderDoc]

<..> I think the 600 nGy/h peak shown on March 21st was caused only by rain, without being related to any specific incident at the plant.

That's possible, however on March 21st, as a new development, quite a lot of grey and black smoke was seen coming out the unit 3 reactor top, and going inland. Here's from unit 3, March 21st:

 

[Rive]

It looks like taken from a HD-cam though, just rendered to a lower resolution.

It's a common solution for every remote controlled vehicle that the 'live' feed for the operator is reduced in resolution to preserve bandwidth, and the HD recordings are stored locally or sent/taken only by request.

The same with the T-Hawk. The very first footage was the live feed for the operator, with awful resolution, clearly with analog transmit. Then later on there was some digital HD recordings.

 

[ascot317]

It's a common solution for every remote controlled vehicle that the 'live' feed for the operator is reduced in resolution to preserve bandwidth, and the HD recordings are stored locally or sent/taken only by request.

The same with the T-Hawk. The very first footage was the live feed for the operator, with awful resolution, clearly with analog transmit. Then later on there was some digital HD recordings.

Have a look at the footage, none of it is directly from the bots. It's all filmed by someone else with a camera, watching over the operator's shoulder. There's no reason to provide it as 320x180 pixels as they do. The aspect ratio suggests it was filmed with a HD camera.

 

[tsutsuji]

That's possible, however on March 21st, as a new development, quite a lot of grey and black smoke was seen coming out the unit 3 reactor top, and going inland. Here's from unit 3, March 21st:
http://www.gyldengrisgaard.dk/fuku_docs/20110321_b_Screenshot-5.png

Thanks. I checked the NISA reports and found the following :

Grayish smoke generated from Unit 3. (At around 15:55 March 21st)

The smoke was confirmed to be died down. (17:55 March 21st)

Grayish smoke changed to be whitish and seems to be ceasing. (As of
07:11 March 22nd)
http://www.nisa.meti.go.jp/english/files/en20110324-1-1.pdf

But these smoke events appear to come too late, because the peak was already showing up as early as at 6 a.m. on that morning in Mito according to http://www.bousai.ne.jp/vis/tgraph.php?area_id=108&post_id=1080000014 .

So perhaps the best line of explanation is the one mentioned by I_P

Edit: Unit 3 experienced a rise in pressure on the 20th and TEPCO said they might need to vent it, however the pressure subsequently rapidly fell without intervention. I would be willing to make a serious bet that it 'self-vented' at that time leading to the radiation spike in the surrounding region.

The plot for the Yoshizawa district of Mito city includes the rainfall data. It started raining at around 8 a.m. on that morning. So I must withdraw my comment about the rain. Coming too late, the rain alone cannot explain the peak. See attachment below (the radiation is the red line, the rainfall is the blue histograms below). Source : http://www.bousai.ne.jp/vis/tgraph.php?area_id=108&post_id=1080000037

 

[Rive]

Have a look at the footage, none of it is directly from the bots. It's all filmed by someone else with a camera, watching over the operator's shoulder. There's no reason to provide it as 320x180 pixels as they do. The aspect ratio suggests it was filmed with a HD camera.

After the first flights of the T-hawk it was some days to release the analog footage and after that even more days waiting for the HD recordings. So maybe within some days we will see.

 

[ascot317]

After the first flights of the T-hawk it was some days to release the analog footage and after that even more days waiting for the HD recordings. So maybe within some days we will see.

This isn't the signal transmitted by the robots, it's taken by a handheld camera, aimed at the controller's screen, so your analogy to the T-Hawk (there has been no releases of "HD" footage either) isn't really fitting. Btw, the T-Hawk is made for real time combat recon. The unit itself doesn't store video, the ground control station does. The "ground control station" itself is a simple laptop you can strap to your chest. It stores the video as it is (in "LD").
The T-Hawk can also offer IR video (SFP, please!), and I bet Tepco has a lot of footage, but they're not releasing it.

What we're seeing here is very likely the unwillingness to inform the public properly, paired with technical incompetence.

Same with the robots. KHG had offered its assistance (KHG is a German company specialised in nuclear disaster response). Their robots are designed exactly for this environment, hardened against radiation (100Gy/h), able to navigate through difficult terrain and fitted with all kinds of different tools. Instead, Tepco went with "HazMat" combat robots and taped a geiger counter to it. In the end, they couldn't even read the counter due to fog.

Tepco could have uploaded it as it is, in HD, but instead decided to reduce the resolution. The resolution is just bad enough to be unable to read most of the sensor data. This isn't the ISS where downloading HD takes some time, this is Japan, where people can have 1GBit-connections at home. And even if they had to stay on site, there are more than enough ways of getting high speed internet access (one way would be driving to the next city). Okay, this being Tepco, I bet they're using phone lines (56k dial up, yay).

I'd like to know what's going on, but what Tepco is giving us isn't much, and even worse, it seems like they don't know much for themselves.

 

[jlduh]

To etudiant (probably french like me ;o))

I wouldn't share your view of just letting the stuff resting "quiet" like that on purpose! The problem is what alternative (credible) can they have right now other than flooding the all plant at a rate of around 6 to 7 m3 of water per hour on each n°1 to n°3 reactors with water injected inside the cores or the vessels which go in direct contact with fuel and so get charged with high radiaoctivity? They are not in close loop for water cooling and i don't see how they could go that way in the near or even mid term considering the mess, destructions and radioactivity around the reactors vessels which annihilates any efforts to repair the damages (if even it could be possible) to go in close loop.

Then this thing still has to continue to be cooled anyway, cold stop is a misleading term because you tend to think that the stuff is "cold" but it is not: it is only cold and somewhat stable because of active cooling, even at reactor n°5 and 6 or at Daini. The thermal power to remove is decreasing with time following an exponential decay but it is still there.

Then the contaminated water volume on site is growing and growing, and if we can consider that this contamination in water is less susceptible to travel at long distances from the plant (it can though ocean currents and underground travel, but it is of course a process much slower that what happens with direct release through the air masses), the consequence is also that water on site will concentrate contamination and release it in the surroundings through leaks and/or overspilling. Even if they manage to install on site a water treatment facility for all this water, the leaks will still be there...

Underground water is a very sensitive compartment, because it can travel a very long way at quite small speeds, with wery little possibilties to treat the contamination. Then it means pollution of soils and of all the usages by humans of this underground water (drinkable water, agricultural use in the fields, etc.). Depending on the phreatic structure in the area, you can also have pollution of the rivers of course.This is a very tricky situation which is far from "quiet". If you intend "quiet" as no "big boum", yes it is quiet. But some quietness and silence can be worse than impressive images in medias right after the beginning of the catastroph. Tchernobyl has been a high pace disaster (with long consequences), Fukushima turns to be a much smaller pace disaster but with very very long consequences.

This has nothing to do to with the "strategy" chosen to deal with the mess: it's just the mess that is different. But both are fist class (or INES 7 if you want, to express it in technical wording...).

Concerning the robots: i agree that if Tepco is releasing so many useless videos from the robots, it's maybe to feed the dog with something and try to show that high tech is there like cavalry in bad situations scenarios! But if you consider that these expensive toys can only go in environments with small debris (they have also wires following them for power!) no way these can do more than a little bit of surveyance and small operations, which is a scale much different that the scale of the damages and the operations to be conducted on site...

 

[clancy688]

Regarding the radioactive contaminated underground water in the basements of Unit 5 and 6:

I have just read a very interesting post regarding this matter in a german Fukushima board - http://fukushima.physikblog.eu/discussion/33/radioaktivitaet-im-grundwasser-noch-so-ein-thema

It's very large, so I'll try translating the most vital parts. All thoughts come frome user Silene in the german forum, I'm only reciting. But I think it's very plausible.

Here is an image of the sweetwater/saltwater levels at coasts:

Notice that the saltwater is forming a wedge which's pressing inland. Since saltwater is more dense than sweetwater, sweetwater is pushed upwards near the coast, it's floating on the saltwater.
The water leak which was sealed earlier this month can't be responsible for the big seawater contamination which was measured since there was only a release of 7m³/h. It's more likely that the saltwater, which was previously used to cool the reactors, seeped through the ground, passed through the sweetwater (because it's denser) and mixed with the saltwater. That way, it could have gotten into the ocean.
Now the reators are cooled with sweetwater. The sweetwater is staying with the groundwater and the overall groundwater level is rising -> radioactive groundwater begins seeping into Units 5 and 6.

 

[Samy24]

To etudiant (probably french like me ;o))

... Concerning the robots: i agree that if Tepco is releasing so many useless videos from the robots, it's maybe to feed the dog with something and try to show that high tech is there like cavalry in bad situations scenarios!...

"to feed the dog with something" that is how the public is feeling about the information "policy" of TEPCO.

But why are they doing so?
To hide the real size of the disaster? -> It's INES 7 already.
To secure "engineering secrets"? -> I do not belief the Iran like to copy this crap.
TEPCO itself do not have more data, pictures and information? -> God forbid.

 

[clancy688]

Maybe they're trying to not lose their face or something like this...? I hear it's very common in japan.

 

[Dmytry]

There's a version of the robots they use, which includes built in radiation monitor.

Does anyone here recognize the model of that monitor they strapped onto a bot? Would be fun to look at it's specs.

 

[MadderDoc]

<..>
But these smoke events appear to come too late, because the peak was already showing up as early as at 6 a.m. on that morning in Mito <..>

All right. During the night between March 20th and March 21st, the Hyper Rescue Unit of the Tokyo Fire Department had a long-lasting operation on the plant, it lasted almost 6 hours, and finished about 4 am on the 21st. According to Tepco press relases the unit were doing spraying to the spent fuel pool of unit 3.

(Note: it is my impression that in this period 'spraying to SFP3' could well have been indicated, while the actual spraying was done to the NW corner of unit3, i.e. the opposite corner from the SFP. I haven't figured out why that corner of the building has been needing so much douching).

 

[AntonL]

Underground water is a very sensitive compartment, because it can travel a very long way at quite small speeds, with wery little possibilties to treat the contamination. Then it means pollution of soils and of all the usages by humans of this underground water (drinkable water, agricultural use in the fields, etc.). Depending on the phreatic structure in the area, you can also have pollution of the rivers of course.This is a very tricky situation which is far from "quiet". If you intend "quiet" as no "big boum", yes it is quiet. But some quietness and silence can be worse than impressive images in medias right after the beginning of the catastroph. Tchernobyl has been a high pace disaster (with long consequences), Fukushima turns to be a much smaller pace disaster but with very very long consequences.

Underground water has been analysed once and then conveniently forgotten, at the time of the release of sub-drain or underground water analysis the headlines was the leak into the ocean.

On 31 March Tepco published underground water (or sub-drain) water http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110331e18.pdf

On 4th April following sketch was published by meti explaining sub-drain http://www.meti.go.jp/press/2011/04/20110404003/20110404003-5.pdf which basically is a sub soil drain below foundation level, as we can see from the results major leaking of contaminated water is taking place into the the sub-soil and subsequently into the underground water.

 

[tsutsuji]

All right. During the night between March 20th and March 21st, the Hyper Rescue Unit of the Tokyo Fire Department had a long-lasting operation on the plant, it lasted almost 6 hours, and finished about 4 am on the 21st. According to Tepco press relases the unit were doing spraying to the spent fuel pool of unit 3.

(Note: it is my impression that in this period 'spraying to SFP3' could well have been indicated, while the actual spraying was done to the NW corner of unit3, i.e. the opposite corner from the SFP. I haven't figured out why that corner of the building has been needing so much douching).

It is a pity that the Radiation dose measured in the Fukushima Daiichi Nuclear Power Station[/url] data have a gap between March 20th 3 p.m. : http://www.tepco.co.jp/en/nu/monitoring/11032001a.pdf
and March 21st 0 a.m. : http://www.tepco.co.jp/en/nu/monitoring/11032101a.pdf

 

[rowmag]

On 4th April following sketch was published by meti explaining sub-drain http://www.meti.go.jp/press/2011/04/20110404003/20110404003-5.pdf which basically is a sub soil drain below foundation level, as we can see from the results major leaking of contaminated water is taking place into the the sub-soil and subsequently into the underground water.

I wonder if that could have been a leakage path for hydrogen from, say, Unit 3 to Unit 4...
Though, if so, it seems like hydrogen should also have leaked into the turbine hall. Guess there will be no way of knowing without a full map of underground conduits on-site.

 

[rowmag]

Does anyone know about the use of hydrogen peroxide in BWR's during shutdown. I'm interested in storage (in or out of reactor building), added concentrations in reactor and SFP.

For example:

"Appropriate biocides (hydrogen peroxide) at concentrations up to 1000 ppm were added (to the pool water) to control biofouling."

From: http://www-pub.iaea.org/MTCD/publications/PDF/te_0944_scr.pdf

Also anyone with knowledge about what chemicals might be stored/used (in or near reactor) during BWR shutdown that might interact with hydrogen peroxide (powerful oxidizer).

I have a feeling that hydrogen peroxide may have played a role in the explosion at the Fukushima Diiachi #4 reactor building.

Reactor 4 was undergoing shroud replacement, which uses apparently uses oxalic acid and hydrogen permanganate for decontamination:
http://www.toshiba.co.jp/nuclearenergy/english/maintenance/replace/shroud04.htm

Oxalic acid "reacts explosively with strong oxidizing materials"...
http://www.jtbaker.com/msds/englishhtml/o6044.htm

?

 

[rowmag]

The expertise deployed on this forum to understand the processes which reduced four multi billion dollar reactors to steaming scrap is laudable.
For an outside observer, it would be wonderful if this expertise were also employed looking forward, to help evaluate and understand the challenges and risks posed by the clean up plan.
For instance, Areva is scheduled to have a water processing plant built by the end of June that will process 1200 tons of water/day. There are nearly 70,000 tons currently in the facility, increasing at 500tons/day, so there will be 100,000 tons by the time the plant is operational.
The plant will start to whittle down the flood at about 700 tons/day net once it starts, so it will take 150 days to drain the facility, if all goes well.
That says the cleanup will not begin until very late this year at the earliest.
Is this a plausible schedule? How does it tie into the TEPCO indication that the immediate crisis should be stabilized within 9 months? What are the risks that should be of most concern?

As much as I try to understand what has happened, this is the question that really concerns me. What I really want to know is, when can I stop worrying about this? Right now it seems like they are juggling chainsaws while standing on a banana peel, and the chainsaws are leaking gas. Not yet a stable equilibrium.

As far as I can see, any notion of cleaning things up enough to allow people to do work inside the reactor buildings is hopeless for the time being, which means they will have to restore some kind of cooling loop from the outside before they can even start to think about how to take things apart. Perhaps that means just filtering water from the drainage trenches and feeding that back into the reactors, using some system such as proposed by Areva. I don't know. I really wish I had a brighter idea.

 

[WhoWee]

I wonder if that could have been a leakage path for hydrogen from, say, Unit 3 to Unit 4...
Though, if so, it seems like hydrogen should also have leaked into the turbine hall. Guess there will be no way of knowing without a full map of underground conduits on-site.

Blueprints would be helpfulbut not certain. Any estimate of the leakage rate required as per your idea?

 

[tsutsuji]

Some more details on what they plan to do :

At the No. 4 reactor, it is necessary to reinforce the structure below the temporary storage pool for spent nuclear fuel rods to prevent any possible spillage. However, this task is also expected to be fraught with difficulty.

Apr. 19, 2011
http://www.yomiuri.co.jp/dy/national/T110418004891.htm

 

[jarvik]

Does anyone know the definition of "daily deposition" as mentioned in http://www.slideshare.net/iaea/radiological-monitoring-and-consequences-19-april-2011 ? Is it the difference of the measured radioactivity from soil samples between that day and the day before ? How do "daily depositions" and "gamma dose rates" relate with each other ?

Looking at the slides, daily deposition is in Bq/m2 or decays per second per m2 for ¹³¹I (slide 4) and ¹³⁷Cs (slide 5) which are two fission products that are both produced in abundance by U fission and easy to measure via Gamma ray spectrometry. These and other radioactive isotopes (natural and fission sourced) will contribute a portion of the total gamma dose rate shown in slides 2 and 3. There are of course other fission (⁹⁰Sr ) and natural sourced radioisotopes that will also be present but do not emit gamma rays (i.e. pure beta emitters) and therefore do not contribute to the total gamma dosage.

I assume they have some sort of surface film on a collecting surface to capture the radioisotopes falling down and this is changed and counted in a gamma ray spectrometer on a daily basis.

Looking at ¹³⁷Cs for Ibaraki the cumulative fallout for the time period of April 1-19 is ~2000 Bq/m2. For a frame of reference the cumulative ¹³⁷Cs activity I find in sediment cores from various places (mostly in North America) tends to be 170-1700 Bq/m2. This ¹³⁷Cs is primarily from bomb testing from the 60s so at the time of deposition it would be about double what I measure now so I don't think that level of ¹³⁷Cs deposition seen in April for Ibaraki is likely to be a big issue. Though I'd be interested in the cumulative ¹³⁷Cs activity in Ibaraki since the beginning of the accident and not just since Aprils 1st, and of course all the other radioisotopes that might be coming down (Tc and Sr come to mind).

 

[AntonL]

OFF TOPIC: Farm animals starve in Fukushima exclusion zone - be warned a very disturbing video

 

[jlduh]

Thanks AntonL for the source data concerning contamination of the sub drain water. I heard reported in the medias that I-131 in high concentration was found in the water table 15 meters below ground level of reactor 1, but in fact the table you posted shows that the situation is much worse than that, because some other values (other elements) are also very high, but not only under 1 reactor but under the six ones, even the ones that are not damaged and leaking (5 and 6)! The value of 430 Becquerels/cm3 at reactor 1 is 10 000 times the limit for underground water, so you have an idea of the numbers we are talking about...

The fact that there is also highly contaminated water under 5 and 6 (which are at some fair distance -severel hundred meters- at the north side of the plant, on a second platform) shows that the contamination has already spread around the initial sources throughout the ground water. What would be important now to know is the direction of flow of this water table, especially if it is flowing inland.

Concerning the hypothesis that the reason why there is water in the basement of 5 and 6 turbines building could be an increase of the level of the water table because of cooling water leakage, i would be very surprised (and scared) if it was the case, because it would mean that a huge volume of this water has already gone into the table. Again, that would be very surprising. Not saying i cannot be the case, but really that would be a very bad news.

An alternate hypothesis is that the basements of the different buildings are in fact built into the water table (so there is underground water around the basement in normal conditions). A little bit surprising when you know the difficulties to have concrete waterproof over years in these conditions, but who knows... The fact that the article cited this morning was saying that Tepco was already pumping leaked water from the outside in 5 and 6 basements BEFORE the accident (and that they then stopped because of other priorities on site) could reinforce this hypothesis.

A third hypothesis can also be that the tsunami has modified the water table level and increased its level... That's an other possible factor.

Concerning the calculation done for the time necessary to treat this daily ongoing flooding of contaminated water on site, yes it shows that this Fukushima story is going to last MUCH LONGER than the Tchernobyl one (as far as "liquidation" process) where the sarcophage was in place one year after the explosion (but with almost 1 million workers who have gone through the site to build it in between). Don't know how many workers are now on Fukushima site, but this is a very different scenario, although in the first class mess category...

At the time of the Tchernobyl accident, all the western experts from nuclear industry where criticizing the russians for their inexperience and stupidity, and their "low tech" of course (meaning: ours is far better of course...).

Well, it seems that time has come for all these brilliants minds to demonstrate that they are far more clever, but also far more EFFICIENT than these silly russians...

 

[PietKuip]

A third hypothesis can also be that the tsunami has modified the water table level and increased its level... That's an other possible factor.

The earthquake may have diminished the elevation of the nuclear power plant.

 

[M. Bachmeier]

Reactor 4 was undergoing shroud replacement, which uses apparently uses oxalic acid and hydrogen permanganate for decontamination:
http://www.toshiba.co.jp/nuclearenergy/english/maintenance/replace/shroud04.htm

Oxalic acid "reacts explosively with strong oxidizing materials"...
http://www.jtbaker.com/msds/englishhtml/o6044.htm

?

Now the question is, would it have been considered safer (prior to earthquake) to store a hydrogen peroxide tank at (50-70% concentration) in the reactor building (which has good filtered ventilation)? I believe hydrogen peroxide (small leak by itself) has a flash point of 70 degrees Celsius without a source of ignition. Not 100% certain?

 

[AntonL]

here is the latest Radiological Assessment estimates published by NNSA
http://www.slideshare.net/energy/ra...ta-from-fukushima-area-04182011?from=ss_embed and reported by http://mdn.mainichi.jp/mdnnews/national/archive/news/2011/04/21/20110421p2a00m0na016000c.html

[PLAIN]http://k.min.us/imWXac.jpg

 

[Borek]

I believe hydrogen peroxide (small leak by itself) has a flash point of 70 degrees Celsius without a source of ignition. Not 100% certain?

Hydrogen peroxide is not combustible.