GLODEP2: a computer model for estimating gamma dose due to worldwide fallout of radioactive debris

Abstract

Thb \t u hrferBH! rtjwt iunM pclourily for lateral or llnilri ritral dfalrihittaa. 1 •fkiloH md cndutHB Kited in ftwt of 4c niter nd my or roiy not he fax af IV LafcorMtry. \ Work ptrlomcd srier ItK uafkes of r»« US. Dtptmam of Ewrgjr hjr the Lawrence LtrtrMtn Ldoraiorj infer Cornet W-7*B.Eo(-48. DISCLAIMERThis report was prepared as an account of work sponsored by an agency of the United States , Governmmt Ncilber Ihe United States Government nor any agency thereof, rot any of their j ' employees, i^afce* any warranty, express or implied, or assumes any Legal liability or responsi bility for the accuracy, completeness, or usefulness of any informatioii, apparatus, product, or process diidoosd, or represent that its use would not infringe privately owned rights. Refer ence herein to aoy opcode commercial product, process, gr service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recomniefldtfitrai or favoring by the* United States Government or any agency thereof. The views end opinions of authors expressed herein do not necessarily state or reflect those of the United Slates Government or any agency thereof. ilS-fi.SM Ofm 3(»-« ts USURHUi ABSTRACT ! The GLODEPZ computer code provides estimates of the surface deposition of • "worldwide" radioactivity and the gamma-ray dose to man from intermediate and i long-term fallout. The code is based on empirical models derived primarily from i injection-deposition experience gained from the U.S. and U.S.S.R. nuclear tests in | 1958. i -3-Tne HAS report does not examine these problems. However, C. V. Chester and R. O. Chester [4] published a study of local fallout from nuclear power facilities in 1976. The AMBIO [2] publication also addresses this problem.The objective of this report is to document the development of a computer code, GLODEP2, capable of estimating the potential hazard due to gamma-ray dose from radioactive worldwide fallout.Local fallout occurs mostly downwind of the detonation site on a time scale of hours to a day after the burst and will not be considered in this report. Intermediate fallout occurs on a time scale of days to a month or two. The debris cloud encircles the globe, perhaps several times, as a diffusing cloud of decreasing radioactivity. This portion of the fallout is contained within the troposphere, the first 9-17 km of the atmosphere. A Gaussian diffusion deposition model is employed to model this fallout.Long-term fallout is defined as debris initially placed into the stratosphere, or higher, that deposits over the globe on a time scale of months to years after nuclear events. In GLODEP2 this fallout is modeled in essentially the same manner as that reported by Peterson [5] in 1970.Given the yield, fission fraction, height of burst, latitude and season of each nuclear burst and the type of nuclear installation (if any) involved, the fractional injections into the atmosphere and surface deposition of radioactive debris is predicted. This debris is then converted to a gamma-ray...