Document: NUREG-0800
Document ID: 3320f197-9b8e-4c8c-a548-d533a1f691f4
Document Type: srp
Title: RADIOLOGICAL CONSEQUENCES OF A CONTROL ROD EJECTION ACCIDENT (PWR)
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052350416.pdf
Revision Date: 2023-06
Chapter: 15
Section ID: 15.4.8
CFR Part: 
CFR Title: 

Content:
fractions of fission gases corresponds to the initiation of melting as opposed to the 280 cal/gm used as a criterion by the CPB for core disruption. It is assumed that the fission products released to the primary coolant due to fuel failure or melting are instantaneously and uniformly mixed in the primary coolant at the time of the'accident. 3. Fission product release path to the environment: Two releases paths to the environment are considered independently for this accident: first, containment leakage of fission products released from the primary system to the containment; and second, leakage from the secondary system, outside 15.4.8-6 Rev. 1 - July 1981 containment, following primary-to-secondary leakage in the steam generators. For releases via the containment building, 100% of the noble gases and 25% of the iodines contained in the fuel which is estimated to reach initiation of melting are assumed to be available for release from the containment. For releases through the secondary system, 100% of the noble gases and 50% of the iodines contained in the fuel which is esti- mated to reach initiation of melting are assumed to be released to the primary coolant. 4. The standard technical specifications for each of the three PWR vendors' NSSS include limits on the primary-to-secondary coolant leak rate. These limits are used by the staff in its dose calculation when plant-specific technical specification limits are not available. 5. Determination of the atmospheric dispersion characteristics (X/Q values). The appropriate X/Q values are determined by the'assigned meteorologist in accordance with SRP Section 2.3.4. 6. Calculation of the EAB and LPZ doses. The reviewer performs an independent calculation of the thyroid and whole-body doses for the two release paths above (i.e., containment leakage and secondary system leakage outside containment). The actual doses for the postulated accident would be a composite of the doses computed for the independent releases via the