Technology, safety and costs of decommissioning a reference boiling water reactor power station. Appendices. Volume 2

Abstract

On the average, days per year have maximum temperatures of 32°C and above. Annually, an average of 168 days have minimum temperatures of 0°C and below, with 40 of them at -18°C or below. The January average relative humidities at 7:00 a.m., 1:00 p.m., and 7:00 p.m. are 76, 68, and 70%, respectively. The corresponding humidities for July are 86, 55, and 55%.The average annual rainfall in the area is 610 mm. The months of May through September have the greatest amounts of rainfall, with an average during this period of 432 to 457 mm (70% of the annual total). The maximum 24-hr total rainfall for the period 1894 through 1965 was 127 mm and occurred in May. Thunderstorms, with an average annual frequency of 36, are the chief source of rain from May through September. Snowfall in the area averages 1070 mm annually, with occurrences recorded in all months except June, July, and August. The extremes in annual snowfall of record are 152 mm minimum and 2235 mm maximum.Annually, the winds are predominantly bimodal. This bimodal distribution is characteristic of the seasonal wind distributions as well. The average wind speed for spring is 11 km/hr and for the other seasons is about 16 km/hr. The maximum reported wind speed of 148 km/hr was associated with a tornado. Tornadoes and other severe storms occur occasionally. Eight tornadoes were reported from 1916 through 1967 in the county where the site is located. The probability of a tornado striking a given point in this area is about 5 X 10~ per year. For design purposes a wind velocity of 480 km/hr is assumed to be associated with tornadoes.Natural fog that restricts visibility to 0.4 km or less occurs about 30 hr/yr. Icing caused by freezing rain can occur between October and April, with an average of one to two storms per year. The mean duration of icing on utility lines is 36 hr. Diffusion climatology comparisons with other locations indicate that the site is typical of the region, with relatively favorable atmospheric dilution conditions prevailing. Thermal inversions occur about 32% of the year, and the frequency of thermal stabilities is 19% slightly stable, 27% stable, 20% neutral, and 34% unstable. B-4Data from a number of river sites used for nuclear power reactors are used to calculate the "typical" annual atmospheric dispersion pattern in an average 22.5-degree sector around the site. Dispersion factors at selected distances for the average sector are determined from joint-frequency distributions for each site.

Allowable residual-contamination levels for decommissioning facilities in the 100 areas of the Hanford Site

“…The method has continued to evolve as the NRC conceptual decommissioning studies considered a variety of nuclear facilities ranging from fuel fabrication, through reactor operation, to low-level waste disposal and independent spent-fuel storage. Example applications of the ARCL method that directly relate to this study are contained in reports by Smith, Konzek, and Kennedy (1978), Oak et al (1980), and Konzek et al (1982).…”

“…As shown in The direct exposure rate encountered by the intruder for various contamination levels is calculated using the model developed for decommissioning a reference room at a BWR (Oak et al 1980). External dose equivalent factors are calculated for the mixtures of radionuclides at the facilities using the ISOSHLD (Engel et al 1966;Simmons et al 1967) computer program.…”

“…These assumptions tend to maximize the dose to specific internal organs obtained from the TGLM equations and are rather "standard" for situations where the exact chemical properties of radionuclides are not known. External exposures are calculated using the BWR room model (Oak et al 1980) and dose factors from the ISOSHLD (Engel et al 1966;Simmons et al 1967) factors are calculated based on the conservative assumption that 100% of each radionuclide is in the form of removable surface contamination. Modifications can be made to these factors to account for fixed surface contamination.…”

Radiological characterization of spent control rod assemblies

“…During the late 1970s and early I98Os, Pacific Northwest Laboratory conducted a number of studies for the NRC to assess the technology, safety, and costs associated with reactor decommissioning (Smith, et a1 ., 1978;Oak, et al, 1980;Wittenbrock, 1982;Murphy and Holter, 1982;Konzek, et al, 1982). These studies were based on extremely limited radionuclide source terms for residual radioactivity within a retired nuclear power plant.…”

Radiological characterization of spent control rod assemblies

“…During the late 1970s and early I98Os, Pacific Northwest Laboratory conducted a number of studies for the NRC to assess the technology, safety, and costs associated with reactor decommissioning (Smith, et a1 ., 1978;Oak, et al, 1980;Wittenbrock, 1982;Murphy and Holter, 1982;Konzek, et al, 1982). These studies were based on extremely limited radionuclide source terms for residual radioactivity within a retired nuclear power plant.…”