BWR Hardened Vented Containment (Some repitition)

Hardened Vented Containment and the Boeing 787 Dreamliner

The Dreamliners were grounded until the batteries were contained and vented.

In contrast, the Fukushima sister BWRs in the USA continue operating without a glitch while our NRC ponders what to do about the lack of venting.  Of course there is a lot of activity and NRC now says that a hardened vent with the capacity to vent the steam/energy equivalent of one (1) percent of licensed/rated thermal power is adequate although a lower value may be justified by analysis.

ML13143A321 Hardened vents for BWRs

The pages are not numbered, but on page 33 of 36:

1.2 The HCVS shall include the following design features:

1.2.1 The HCVS shall have the capacity to vent the steam/energy equivalent of one
(1) percent of licensed/rated thermal power (unless a lower value is justified by analyses), and be able to restore and then maintain containment pressure below the primary containment design pressure and the primary containment pressure limit.

And, the NRC is in no sweat.  Here is the schedule:

These Licensees shall promptly start implementation of the requirements in Attachment 2 to this Order upon issuance of the associated final interim staff guidance (ISG) for each phase, and shall complete the two phases of implementation by the following dates:

• Phase 1 (severe accident capable wetwell venting system): no later than startup

from the second refueling outage that begins after June 30, 2014, or

June 30, 2018, whichever comes first.

• Phase 2, (severe accident capable drywell venting system): no later than startup

from the first refueling outage that begins after June 30, 2017, or June 30, 2019,

whichever comes first.