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From: Versluis, Rob Sent: Friday, March 25, 2011 8:19 AMTo: RST01 Hoc; RST01B HocSubject: Fw: Hydrogen

Follow Up Flag: Follow upFlag Status: Flagged

FyiRo b Versluis +1-301-903-1890(o) m)

From: Kelly, John E (NE)To: DL-NERT-AIISent: Fri Mar 25 00:10:21 2011Subject: FW: HydrogenHere is new information from the Japan AEC. I know GE thought that the vented via a wetwell line, but this is adifferent interpretation. This scenario means that the head bolts stretched, which GE didn't think was what happened. Iwill need the pressure histories for the first multiple hours of the situation (especially In the containment) in order toprovide a response. Have we plotted that info yet?

From: Akiraomoto [mailto:l b)(6) -Sent: Thursday, March 24, 2011 11:46 PMTo: Kelly, John E (NE)Cc: Lyons, Peter; shunsuke.kondo@cao.go.jp; Binkley, Steve; SCHU; Poneman, Daniel; Connery, Joyce;akira.omoto@cao.go.jpSubject: Re: HydrogenDear Mr. John Kelly,

Akira OMOTO, a Commissioner in the AEC is writing to you.Thank you for sending your note.I thought that the following points need to be considered;1) SAM (Severe Accident Management) procedure and modifications were finished in the 90'sincluding containemnt "hardened" scrubbing venting to the main stack (NYT article is wrong) viawetwell air space, makeupo water using fire protection system from large size portable waterstorage tank, bus inter-connection to other units (this worked very well in unit 5 and 6 since oneED G continued operation), and others.2) All the three units (IF] -3) experienced containment overpressure in the early phase of theaccident, which caused excessive leakage from flange, ailocks and other peentrations. Hydrogen

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produced by Metal Water reaction in the core damage process must have escaped to the ractorbuiding via this containment leakage path and acculmulated on the top and causeddeflagration/detonation there. Further, containment was steam inerted and a large fraction ofhydrogen escaped -by "hardened" venting.3) Still radiolysis of water is ongoing and produces hydrogen/oxygen in the containement(hopefilly in the RPV). thus, still the risk of hydrogen deflagration/detonation exists, in my view.Remeber that if lodene and other Halogen elements exist in the water they function to retard orprevent recombination of hydrogen/oxygen.My paper oni hydrogen control in BWR (Nuclear engineering and Design, 2000) discussed thispoint.Study is ongoing in TEPCo;a) to open vent valve of RPV while keeping steam inert conditionm andb) to send nitrogen or other inert gas to the containment. However, to inject nitrogen containmentisolation must be unlocked first and then valve operation must be done in an extremely harshenvironment.A professor in Georgia (in eastern Europe) suggested injection of overcooled nitrogen (which hadbeen used in Russaian and Eastern europe's research reactor) adn I am asking the details, but noanswer yet.akira OMOTOiPhone 6 L1AOn 2011/03/25, at 5:06, "Kelly, John E (NE)"

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am hoping these can be provided to you promptly.Restoration of fresh water cooling is of great interest, as you note, and your efforts to restoresuch cooling by bringing in supplies from that dam are very positive. 1 believe there is alsodiscussion of a Navy bargebringing in fresh water offshore.Thank you for your note and our thoughts are with you,Very best regardsPete

-----riginal Message -----From: shu nsRu.-lo (_o ct, u.Q [maihto:shunsuke.kondoCcao.go.ip]Sent: Wednesday, March 23, 2011 7:55 PMTo: Lyons, PeterCc: SCHIU; Poneman, Daniel; Connery, Joyce; 1irz.otxmLcw ioCj:Subject: HydrogenDear PeteWe are still in dangerous conditions. Iwant to ask your experts view on the following twopoints. Official contact between NISA and NRC is working but still slow from my viewpoint,though I am asking people in charge to improve. This is the reason why . want ask you a favor ofgathering opinion of your people on these points informally.Yours,Shunsuke

Dfinition of the problemI. Status of the reactor (1Fukul,2 and 3)Currently, seawater is continuously injected to the RPV boundary through CS (unit I) or LPCI(unit 2 and 3) lines at a speed of around 10-15 Ton/hr. Water level close to TA F level (2/3 of fuelheight covered) must have been achieved already even though the integrity of the RPV boundarymay be lost and core fuel would have lost its integrity.Since the water is supplied by non-conven~tional method (Fire Engine and Seawater), stable andsustainable core makeup and cooling method must be established while minimizing risks arisingfrom potential hydrogen deflagratiornidetonation inside the containment.In reality, the hydrogen explosion presumably occurred at reactor building top floor at IF1 and 3indicates hydrogen leaked from containment penetration (airlocks, flanges, electric penetrationsexposed to high pressure and temperature crated a condition of excessive leakage) or viacontainment vent path had accumulated outside of the containment and detonated.Containment re-inerting by injection of nitrogen is being studied by TEPCO.Restoration of electricity (already power is available to power centers but replacement of pumpmotors such as Make-up Water system pump motor at a harsh (in term of radiation) environmentis causing delay of field work). Use of portable water from nearby dam is planned and onsitereceiving tank has already received this water. Restoration of the supply line to tanks such asCondensate Storage Tank is planned by again in a harsh environment. Once fresh water supply issecured, seawater is to be replaced by fresh water.

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2. Your view is expected:a) HydrogenAlthough temperature reading (RPV surface thermocouple) registered gradually lower numbersat unit 1,2 and 3 (from 500 degC to 200-300 degC), still there is a risk of hydrogendeflagration/detonation inside the containment.What is the estimated potential of hydrogen deflagrationidetonation inside the containment andRPV?What action do you recommend to avoid this risk?b) Lonig-term stable coolingGiven the potential of taking a long time for restoration of ordinary cooling function, whatalternative cooling method is conceivable besides Fire Engine?

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