Document: NUREG-0800
Document ID: 06ca0ca1-d4e9-478b-ad5d-c52597a36b46
Document Type: srp
Title: COOLANT SOURCE TERMS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1305/ML13058A173.pdf
Revision Date: 2023-06
Chapter: 11
Section ID: 11.1
CFR Part: 
CFR Title: 

Content:
eactor coolant and reactor steam source terms should be based on: A. an offgas rate of 3.7 megabecquerels per second per megawatt thermal (MBq/s per MWt) (100 microcuries (μCi)/s per MWt) measured or estimated after a 30-minute delay for BWRs; B. 0.25 to 1 percent fuel cladding defects for PWRs; and C. technical specification limits for halogens (I-131 dose equivalent) and noble gases (Xe-133 dose equivalent), whichever are most limiting when compared to criteria (1) and (2) above, as applied in analyses conducted using the guidance in SRP Sections 11.2 and 11.3 and SRP Chapter 15. Activation source terms, including activated corrosion products, should be based on measurements and experience gained from operating BWR and PWR plants of similar design, including TS for primary and secondary coolant concentrations. ANSI/ANS 18.1-1999 is based on such experience and provides information that can be used as a basis for estimating neutron activation source terms. When operating measurements are used, extrapolation of data to equilibrium conditions may be needed to estimate ultimate activation source terms. See SRP Section 12.2 for additional guidance. 10. When the applicant’s calculation technique or any source term parameters differ from that given in NUREG-0016, NUREG-0017, or ANSI/ANS 18.1-1999, they should be described with sufficient detail, and the basis of the alternate method and model parameters should be provided to allow the staff to conduct an independent evaluation. Technical Rationale The technical rationale for application of these acceptance criteria is to define the primary and secondary coolant source terms as precursors in calculating radioactivity levels in liquid and gaseous effluents. In addition, this information is used to assess the adequacy and performance of RWMS in treating process streams and controlling amounts of radioactivity discharged in the environment. The technical rationale for the above considerations is discussed in the following