Document: NUREG-0800
Document ID: dfb421c6-cf9c-447e-ab71-dd0426ce50e5
Document Type: srp
Title: TURBINE MISSILES
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340523.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.5.1.3
CFR Part: 
CFR Title: 

Content:
ponents in the relation 2 N i-l. 1i j-l p2ij pi where P . = Total probability for incurring damage which exceeds the criteria described in subsection II, per turbine year. N = Total number of distinct turbine missile sources per turbine- generator unit, usually identified with the number of low pressure wheels. P = Probability for turbine failure leading to the ejection, of ii missiles due to i- type of turbine failure. P11 6 x 10-5 per turbine year for design over speed failures. 3.5.1.3-4 Rev 2 -.-July 1981 P12 4 x 10-5 per turbine year for destructive overspeed failures (Ref. 4). P2.. = The strike probability with respect to a barrier between the 1J turbine and the target. In case of multiple barriers, it is equivalent to the probability for striking the final barrier betweef the turbine and the target. The J - index refers to the j- wheel on the turbine rotor.. P3 = The probability for damaging the target. This can be either * due to primary missile penetration of a barrier or due to the generation of secondary missiles (e.g., scabbing in concrete), or both. It should be noted that in the case of multiple barriers the value of Pg.. will be determined by a combination of geometric considerations, missill1 deflections, and intermediate barrier penetration estimates (Ref. 5). The usual procedure is to estimate the portion of the total solid angle associated with each ejected missile that is subtended by the target in question. If there are no intermediate barriers, or if all barriers up to the final barrier are penetrated independently of missile state (i.e., energy, impact orientation) then P2ij can be approximated by ~2ij b~ma J,max ma where Ae. - Azimuthal angle *Hbtended by the target with the 3 respect to the j3- wheel. ea. = Maximum azimfthal f1 gle range of fragment trajectories 3,max ejected from the j- wheel. = 10? for inner wheels = 25? for end wheels. = Elevation angle subtended by the target. a = Maximum elevation angle range for a missile (e.g., max