Document: NUREG-0800
Document ID: 23a67737-6e7e-4dfc-9090-dca6a186a7dc
Document Type: srp
Title: RADIOLOGICAL CONSEQUENCES OF MAIN STEAM LINE FAILURES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070679.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.1.5
CFR Part: 
CFR Title: 

Content:
review of the applicant's discussion of the main steam line failure accidents to determine that there are no unusual design features that would preclude the limitation of radiological consequences by appropriate limits on coolant concentrations and primary-to-secondary system leak rate. The applicant's discussion of the main steam line failure accidents is reviewed to confirm that there are no unusual design features that would render technical specification limits ineffective in controlling the radiological consequences of such events. The detailed review of radiological consequences of the main steam line failure 23 accident is done at the operating license (OL) or combined license (COL) stage when system 24 parameters are fully developed. The standard technical specifications for the nuclear steam supply system (NSSS) of each of 25 the three PWR vendors include limits on the primary and secondary coolant activities and primary-to-secondary leak rate. These limits are used by the staff in its independent dose calculations when plant-specific technical specifications are not available. If the applicant proposes to use these standard limits and the plant is one of the standard NSSS/BOP plants for which the steam line failure accident has been evaluated generically with the standard coolant activity and leakage limits, then the reviewer need not reevaluate the offsite doses from this accident provided that the atmospheric dispersion factors (X/Q values) for the site under review are lower than the limiting X/Q used in the generic review of the standard plant steam line failure. The reviewer need not reevaluate the offsite doses from this accident provided (1) the plant is one of the standard NSSS/balance-of-plant units for which the steam line failure accident has been evaluated generically with the standard coolant activity and leakage limits, (2) the applicant proposes to use these standard limits, and (3) the atmospheric dispersion factors (X/Q values) for the