Pressure Effects Analysis of National Ignition Facility Capacitor Module Events

摘要

Capacitors and power conditioning systems required for the National Ignition211u001eFacility (NIF) have experienced several catastrophic failures during prototype 211u001edemonstration. These events generally resulted in explosion, generating a 211u001edramatic fireball and energetic shrapnel, and thus may present a threat to the 211u001ewalls of the capacitor bay that houses the capacitor modules. The purpose of this 211u001epaper is to evaluate the ability of the capacitor bay walls to withstand the 211u001eoverpressure generated by the aforementioned events. Two calculations are 211u001edescribed in this paper. The first one was used to estimate the energy release 211u001eduring a fireball event and the second one was used to estimate the pressure in a 211u001ecapacitor module during a capacitor explosion event. Both results were then used 211u001eto estimate the subsequent overpressure in the capacitor bay where these events 211u001eoccurred. The analysis showed that the expected capacitor bay overpressure was 211u001eless than the pressure tolerance of the walls. To understand the risk of the 211u001eabove events in NIF, capacitor module failure probabilities were also calculated. 211u001eThis paper concludes with estimates of the probability of single module failure 211u001eand multi-module failures based on the number of catastrophic failures in the 211u001eprototype demonstration facility.