Document: NUREG-0800
Document ID: 2133c57c-1767-4769-89e9-ceb528fb7c2b
Document Type: srp
Title: RADIOLOGICAL CONSEQUENCES OF STEAM GENERATOR TUBE FAILURE
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350149.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.6.3
CFR Part: 
CFR Title: 

Content:
e immediately due to flashing and atomization. Credit may be given for. "scrubbing" of iodine contained in the steam phase and in the atomized primary coolant droplets suspended in the steam phase for release points which are below the steam generator water level. That fraction of the primary coolant iodine which is not assumed to become airborne immediately enters the secondary system water and is assumed to become airborne at a rate determined by the steaming rate and iodine partition coefficient. An iodine partition coefficient of 100 between steam generator water and steam phases may be conservatively assumed unless the applicant presents reasonable evidence that the use of some other value is justified. 11. Calculation of the exclusion area and low population zone boundary doses. The reviewer performs an independent calculation of the doses for the steam generator tube failure accident, using the two iodine concentrations in item (6) above. A breathing rate of 3.47 x 10-4 m3/sec is used in the calculation of thyroid doses for the first 8 hours following the steam generator tube failure and the dose conversion factors are in accordance -with Regulatory Guide 1.4 (Ref. 3). 12. Review of dose calculations. The whole-body and thyroid doses calculated by.the staff and by the applicant are compared with the acceptance criteria stated in subsection II. If the doses calculated by the staff are not within the exposure guidelines (i.e., they are not less than 10 percent of 10 CFR Part 100, Section 11), then the staff will pursue 15.6:3-4 Rev. 2 - July 1981 alternatives with the applicant to reduce the doses to within the guideline values. IV. EVALUATION FINDINGS The reviewer verifies that sufficient information has been provided by the applicant and that the applicant's analysis and the staff's independent calculations support conclusions of the following type, to be included in the AEB safety evaluation report at the operating license stage: The steam generator tube