Long-Term Tracer Study at Los Alamos, New Mexico. Part I: Wind, Turbulence, and Tracer Patterns

Abstract

An array of three portable, pressurized ionization chambers (PICs) measured external radiation levels during 1986 and 1987 caused by radionuclides emitted from a 30-m stack of the Los Alamos Meson Physics Facility (LAMPF). Three PICs were located from 700 to 900 m north to northeast of the release stack, across a 120-m-deep canyon, and at the closest off-site location. Four additional PICs were deployed during 1987 at various sites and directions, at distances varying from 550 to 2700 m downwind of the stack. Winds were measured near the source and 700 m downwind, across a deep canyon. Analysis of monitoring data confirmed that a predominant mountain-valley wind up the Rio Grande Valley during the evening and early morning transported the emissions to the north-northeast and northeast of LAMPF, causing the highest external atmospheric radiation levels there. Daytime winds are southerly and southeasterly, transporting more radionuclides to the north and northwest. Because of increased turbulence, external radiation levels were generally lower during the day.