April 2011 – Mysterious untitled Japanese diagrams of Fukushima Daiichi sent to NRC

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Maybe the current situation is

a) -700/0 of injected water escaping as steam from the containment (1 F1 ,2,3)
b) 30% of injected water (7 tons/hr) leaking to Tb/B through leakage hole in SIC air space (1 F2)

Estimation from parameter adjustment to fit to pressure change history after March 21st (stabilized pressure and temperature, especially for 1F2I3)

Near-term stable cooling

a) Limited leakage of steam to the air or of water Tb/S, no MeCI
b) By the use of temporary heat exchanger” to remove heat from drywell “pool”
c) Linkage with offsite actions (limited re-entry?)

Long-term stable cooling (natural heat removal)

a) Debris in water (e.g. min. feed water flow)
b) Surrounding structure on the top of reactor building and recovery of consdensate (by September/E)

1. Can WL reach TAF level or just below the level of drywell vent line?
2. Quantify the benefit from the use of temporary Hx in terms of days Reduced feed flow, reduced steam leakage, reduced time to reach Near-term stable cooling
3. Long-term stable cooling with the debris in dry atmosphere ?(corrosion concern, MCCI concern)

1) Near-term safe/stable condition (Limited leakage to the air or turbine building, no MCCI) to Long-term safe/stable condition (natural heat removal) in wet condition, e.g. debris in water)
2) “bleed to the air” (maybe currently -70% of injected water escaping as steam)

Near-term: Use of BE model considering “bleed to the air” (maybe currently -70% of injected water escaping as steam) and “use of temporary heat exchanger” to remove heat from drywell “pool”

GOAL: Minimize red line flow

Modeling uncertainties:

1) Can WL reach core debris level, considering leakage from CV? (1 F2/3: Maybe most of the debris in ex-vessel)
2) How much Q steam leakage condensate in the reactor building and not escape as Qair?
3) How much Q leak is flowing to Turbine building?
4) Level of stratification of drywell water pool

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