Total Fukushima radiation releases compared to total core inventories

[Caniche]

Hmm, do you think the SFP's were designed to cope with the impact of 175 tons of RSJ falling from a height of 10 m. :-(

 

[NUCENG]

Something interesting:



http://www.webcitation.org/5xunDms1r

81 million TBq... that's more then ten times the 6 million TBq I have estimated with NUCENGs methods.

My numbers were based on conservative cycle lengths, exposure, enrichment and fuel design. The nubers they are quoting are even more conservative estimate of I-131 at shutdown, but they are using that big number to say less than 1% was released which then sounds like an artificially low number to make a point.

 

[Arizonan]

"We could say all the I-131 was gone." Well, we could say that except that TEPCO reports increasing amounts of I-131. If intermittent criticality is still producing I-131, you may be calculating total inventory loss for some time to come.

Thanks for your answer.

Interest: Yes, mainly I131 and C137. Other isotopes are not of concern. I played a little with the Chernobyl radioactive materials and IAEOs I131 conversion table. In Chernobyl, I131 and C137 alone were responsible for over 80% of the converted I131 activity. Other isotopes won't change the "danger"-math.

Ignoring: Yeah, of course.

Core retaining: I skimmed through your documents but didn't find charts for core releases based on partial meltdowns and containment venting. I have to admit that I was hoping for your response when I created this thread. There's only a german source which calculated core releases based on different accident scenarios:
http://www.biu-hannover.de/atom/unsicher/teil2.htm#4
I think in our case it's something between "Heizrohrleck I am Dampferzeuger" (don't know how to translate this - probably a leak in the condenser) and "Kleines Leck I am Sicherheitsbehälter (Niederdruckpfad)" (Containment leakage)
Overall I'd think that 1-10% of the core inventory of I131 and C137 has escaped.

Airborne release: Well, that's the only thing we know for sure, since there are the NISA numbers they used for INES-7

Liquid release: That's a good question... I think all damaged or broken fuel rods have probably released most of their fission products into the basement. The constant waterflow should have washed it out.

Age for spent fuel: I think if we're only concentrating on C137 then age should be of no concern. We could say that all iodine is effectively gone, but that nearly all of the original C137 is still there. I don't think that the rods are older than five years.