Document: NUREG-0800
Document ID: 49aefb86-1adb-4b3c-826f-480e32947595
Document Type: srp
Title: Radiological Consequence Analyses Using Alternative Source Terms
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0037/ML003734190.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.0.1
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se to use the AST only in analyses supporting limited plant modifications. The reviewer should ensure that the proposed selective implementation is technically justified and that a clear, logical, and consistent design basis is maintained. Since there are a large number of possible selective implementations, only generic review procedures can be provided. The reviewer will have to apply judgement. The following should be considered: (1) A selective implementation on the basis of only the timing characteristic of an AST may be acceptable without dose calculations, provided other impacts, if any, are adequately dispositioned. The acceptability of other combinations of AST characteristics is not as clear. The reviewer must ensure that the proposed combination is consistent. For example, it would be inconsistent to credit the chemical form as being cesium iodide (CsI) and ignore the increased cesium (Cs) release fraction. (2) As previously discussed, a selective implementation need not involve dose calculations. If dose analyses are performed, the TEDE criteria in 10 CFR 50.67 and Section II of this SRP section become the design basis criteria for those analyses. The previous whole body and thyroid criteria would continue to apply to the analyses that were not affected by the implementation. This dichotomy may cause confusion if there are plant modifications associated with an AST implementation. For example-- (a) A licensee is proposing to modify the standby gas treatment system (SGTS) as part of the proposed AST implementation. The particular modification would affect the LOCA and fuel handling accident analyses. What are the dose acceptance criteria for these two accident analyses? For the remaining unaffected accident analyses? For the control room? Answer: The acceptability of the design change is based on the TEDE criteria for the reanalyzed LOCA and FHA. As the remaining offsite and control room accident analyses are unaffected, the previous acceptance criteria