Document: NUREG-0800
Document ID: db9f5ff5-cad8-4af5-848b-a22889b3fb51
Document Type: srp
Title: describes the design acceptance criteria for waste gas systems (as part of the
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0707/ML070730056.pdf
Revision Date: 2023-06
Chapter: 11
Section ID: 11.3
CFR Part: 
CFR Title: 

Content:
the event leading to the release, release path from the affected system and building to the environment, type of release, duration of the release, basis for the noble gas source term, assumed receptor location, atmospheric dispersion parameters, and any modifying factor specific to the event. BTP 11-5-5 Revision 3 - March 2007 ii. The radiological impact should be determined using the noble gas radionuclide inventory determined step 1 above, total-body dose factor listed as DFBi in Table B-1 of Regulatory Guide 1.109, in mrem-m3/pCi-yr, any modifying factor specific to the event, and the relative concentration (X/Q, in s/m3) at the nearest exclusion area boundary given in Figure 1 of Regulatory Guide 1.24 for ground-level releases. iii. The dose, summed over all radionuclides, shall not exceed 25 mSv (2.5 rem) for systems designed to withstand explosions and earthquakes, or 1 mSv (0.1 rem) for systems not designed to withstand explosions and earthquakes. Using the same parameters, a corresponding TS can be defined to set a curie limit on a tank, based on the maximum of 25 mSv (2.5 rem) or 1 mSv (0.1 rem) at the nearest exclusion area boundary and same noble gas mixture to assure that the BTP criteria are met at the exclusion area boundary. B. Charcoal Delay Units: The safety analysis for the radiological consequences of a single failure of an active component in a waste gas system with charcoal delay or decay beds assumes that the charcoal unit is bypassed with a 1-hour release to the environs. The staff considers that either a line bypass valve malfunction, control error, or a charcoal bed bypass will require a remedial action by isolation and that starting an alternate charcoal unit, if available, or reducing reactor power could take up to 2 hours. The following general procedural steps should be used for this analysis: i. The radioactive noble gas inventory should be determined based on the maximum expected radioactive source term and the system design capacity