Document: NUREG-0800
Document ID: 0c95c042-addf-4bad-84f5-1d1692769268
Document Type: srp
Title: CONCRETE AND STEEL INTERNAL STRUCTURES OF STEEL OR CONCRETE
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550052.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.8.3
CFR Part: 
CFR Title: 

Content:
ll surrounds the reactor coolant system. The lower portion of the drywell is surrounded by the suppression pool which is bounded by the containment shell on the outside and by a weir wall located just inside the drywell wall. A series of vent holes connects the drywell to the suppression pool. In the event of a LOCA, the drywell will contain the steam released from the reactor coolant system and, while temporarily acting as a pressure-retaining envelope, will channel the steam through the vent holes and into the suppression pool. The pool water will condense the steam, thus minimizing the energy released to the containment. Following such a LOCA and before blowdown is complete, the drywell will be subjected to a differential pressure and possibly to jet forces. Any structural failure in its boundary would result in steam bypassing the suppression pool and flowing directly into the containment, possibly generating a containment pressure higher than that for which it was designed. 3.8.3-5 Revision 2 - March 2007 With this functional requirement in mind, the review evaluates the general arrangement and principal features of the drywell, with an emphasis on structural framing and expected behavior under loads. Because the drywell geometrically resembles, to a certain degree, a containment, the descriptive information reviewed is similar to that reviewed for containments in Subsection I.1 of SRP Section 3.8.1. The major components of the drywell reviewed, other than the main body of the drywell, include the bottom vent region, the roof and drywell head, and major penetrations. ii. Weir Wall The weir wall forms the inner boundary of the suppression pool and is located inside the drywell. It completely surrounds the lower portion of the reactor coolant system. The review evaluates the general arrangement and principal features of the weir wall, with an emphasis on structural framing and behavior under loads. iii. Refueling Pool and Operating Floor The refueling pool walls