Document: NUREG-0800
Document ID: 65414bbc-012c-477d-8c25-466f94c1671f
Document Type: srp
Title: GASEOUS WASTE MANAGEMENT SYSTEMS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350105.pdf
Revision Date: 2023-06
Chapter: 11
Section ID: 11.3
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CFR Title: 

Content:
t instrumen- tation to assure that setpoints are established on gaseous effluent lines prior to exceeding the limits of 10 CFR Part 20. Therefore, the most credible unique unplanned release would be a major leak or a single active failure of a waste gas system com- ponent releasing gas by a pathway not normally used for planned releases and requiring a reasonable time to detect and take remedial action to terminate the release. The NRC staff considers that the release of a compressed gas storage tank of a batch-type waste gas system or the inadvertent bypass of the main decay portion of a continuous-type waste gas system (such as charcoal delay beds in a BWR augmented off-gas system) would.provide a conservative assump- tion for any unique unplanned release while the input to the waste l. 3-13 Rev. 0 - July 1981 gas system is at the system design basis source term. Only the radioactive noble gases (Xe, Kr, Ar) are to be considered since the assumed transit time is great enough to permit major radioactive decay of oxygen and nitrogen isotopes. Particulates and radio- lodines are assumed to be removed by pretreatment, gas separation, and intermediate radwaste treatment equipment. The release should be assumed to occur within the building structure housing the waste gas system storage tank or main decay position of the system, and be released to the environs without continuous effluent radiation monitoring to automatically isolate and/or terminate the release. Ground-level release without credit for a building wake factor should be assumed, and a conservative (5%) short-term diffusion estimate for the value (x74) determined by a method outlined in the acceptance criteria in SRP Section 2.3.4. No deposition is assumed to occur during downwind transport. II. Staff Method for Analysis a) Pressurized Storage Tanks: The safety analysis for the radio- logical consequences of a single failure of an active component in a waste gas system with compressed gas storage (holdup or