Document: NUREG-0800
Document ID: b761625e-90fd-41e3-a3ae-acaea1aabf84
Document Type: srp
Title: should still be met.
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070476.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.5.1
CFR Part: 
CFR Title: 

Content:
containment sump solution, primary coolant, emergency core cooling system water, and containment spray solution, if any. Long-term retention of iodine may be assumed only when the recirculating fluid meets the pH range specified in the acceptance criteria of this SRP section. For ice condenser systems similar to those of the D. C. Cook and Sequoyah plants (with a steady-state flow rate of approximately 18.9 m /s (40,000 cfm) ), an 3 17 efficiency of 30% per pass for elemental iodine is assigned. The system is considered ineffective for organic iodide and particulate iodine removal. For designs different from those of D. C. Cook and Sequoyah plants, reconsideration of the system efficiency is required. The reviewer should consult References 5, 6, and 78 when evaluating the iodine removal efficiency of the ice condenser. 18 Reference 65 , in particular, should be considered if time-dependent removal 19 efficiencies are used. Reference 84 provides useful background information. 20 Removal efficiencies of time-varying air-steam mixtures or flow rates should conservatively account for factors that affect their time dependencies (e.g., fan capacity, fan activation time, natural circulation rates). DRAFT Rev. 4 - April 1996 6.5.4-6 b. Iodine Scrubbing Function It is not feasible to specify the exact time of the fission product release following a postulated loss-of-coolant accident. In addition, the flow rates and air-steam fractions of the flow through the ice condenser vary significantly during and immediately following the accident. For radiological dose calculations, therefore, the following conservative assumptions are made: (1) If a 30% iodine removal efficiency is used, the iodine removal effectiveness of the ice condenser commences with the establishment of a steady-state air-steam flow. Steady flow is assumed to start with the operation of the postaccident mixing fans. A single failure of one of the fans is assumed. (2) The initial concentration of iodine is