Document: NUREG-0800
Document ID: bcc615f1-3f65-4757-994f-88cc8fe800d5
Document Type: srp
Title: should still be met.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070473.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.5.1
CFR Part: 
CFR Title: 

Content:
and water, alkaline salts or lye additives) in a post-accident containment environment. The minimum iodine partition coefficient determined for these conditions forms the basis of the ultimate iodine decontamination factor in the staff's analysis described in subsection III.4.d. (3) Organic iodides It is conservative to assume that organic iodides are not removed by either spray or wall deposition. Radiolytic destruction of iodomethane may be modeled, but such a model must also consider radiolytic production (Reference 1812) . Engineered safety features designed to remove 36 organic iodides are reviewed on a case-by-case basis. (4) Particulates The first-order removal coefficient, , for particulates may be estimated p by where h is the fall height of the spray drops, V is the containment building net free volume, F is the spray flow, and (E/D) is the ratio of a dimensionless collection efficiency E to the average spray drop diameter D. Since the removal of particulate material depends markedly upon the relative sizes of the particles and the spray drops, it is convenient to combine parameters that cannot be known (Reference 138) . It is 37 DF 1 VsH Vc DRAFT Rev. 3 - April 1996 6.5.2-14 conservative to assume (E/D) to be 10 per meter initially (i.e., 1% efficiency for spray drops of one millimeter in diameter), changing abruptly to one per meter after the aerosol mass has been depleted by a factor of 50 (i.e., 98% of the suspended mass is ten times more readily removed than the remaining 2%). d. The iodine decontamination factor, DF, is defined as the maximum iodine concentration in the containment atmosphere divided by the concentration of iodine in the containment atmosphere at some time after decontamination. DF for the containment atmosphere achieved by the containment spray system is determined from the following equation (Reference 415) : 38 where H is the effective iodine partition coefficient, V is the volume of liquid in s containment sump and sump