Analysis of LAMPF air activation by high-energy particles with LAHET-MCNP
- Westinghouse Hanford Co., Richland, WA (United States)
- Los Alamos National Lab., NM (United States)
Air activation calculations have been performed for the Los Alamos Meson Physics Facility air exhaust system and compared to on-line radioactivity measurements at the gas monitor for the seven most abundant radionuclides produced. Purge air drawn into the exhaust system is activated by high-energy particles, which succeed in penetrating shielding at the targets and at the beam stop. The activated air is transported by blowers to the stack release point. Because this accelerator-generated air activation is the major part of radioactive airborne releases at Los Alamos, its evaluation is an important part of the environmental program. Particle flux spectra vs energy at the targets and beam stop were calculated by the high-energy transport code LAHET and the Monte Carlo code MCNP. The flux spectra were then combined with activation cross section data and a model of the accelerator air exhaust system to calculate production of gaseous radionuclides with the ACTIV code. The predicted production of 41Ar is in reasonable agreement with on-line measurements, considering the relatively minor abundance of its precursor, 40Ar, in air. The agreement shows that the air activation models in this study are basically correct because this reaction is dependent on an accurate prediction of thermal neutron flux. The prediction of total gaseous activity release is also very good, being within 11% of that measured for the last 3 years; the prediction of three important individual radionuclides, 15O, 11C, and 13N, was reasonable and within 50% accuracy.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 10113670
- Report Number(s):
- LA-UR-93-4512; CONF-940424-7; ON: DE94005014; TRN: 94:005521
- Resource Relation:
- Conference: 8. international conference on radiation shielding, Arlington, TX (United States), 24-27 Apr 1994; Other Information: PBD: [1993]
- Country of Publication:
- United States
- Language:
- English
Similar Records
MCNPX{trademark} -- The LAHET{trademark}/MCNP{trademark} code merger
Radiation calculations using LAHET/MCNP/CINDER90