There are many piping and electrical penetrations into the drywell and probably some into the torus as well. I am assuming those penetrations are sealed with a flexable material that has a maximum temperature limit, hence the maximum temp. rating of containment. May we assume that with no power, therefore no cooling of containment with a VERY hot reactor inside that most or all of those penetration seals were cooked early on? If so, movement of air into and out of containment would occur by convection if pressure reached atmospheric..
Thanks for the link!Enjoy. CEPA = Containment Electrical Penetration Assembly
I feel really shocked that the electric drywell insulation specification (at least for Browns Ferry) does not exceed 436K for 15 min, and 411K long-term.
If this is nuclear building code/nuclear electric code conform then these codes are extremely lax.
I fear we have to consider the electric ducts as a possible contamination escape path also.