Library

Notes: Summary Sensitivity of building-energy consumption to changing urban environments is examined by simulating building energy loads in hypothetical urban settings. A modified version of an algorithm developed by the U.S. Army Construction Engineering Research Laboratory is used to evaluate energy requirements. Energy loads for two buildings of interest are estimated for changing climatic conditions (air temperature) as well as changing environments around the building. An isolated building and a building surrounded by several other buildings are considered. Results indicate that climate warming may lead to energy savings in a wide range of climates while savings also depend on the nature of the building and its use. In cool climates, climate warming forces net energy-load decreases through reductions of the winter heating loads. For example, a one-degree increase in annual air temperature in Duluth led to a 10 kWh decrease in net energy loads for a small office building. In warm climates, urbanization tends to accelerate energy consumption although shadowing may contribute significantly to decreases in summer cooling loads. In Phoenix, annual mean daily net energy loads decreased by about 10 kWh due to shadowing for the same office building. Even in relatively cool regions, summer cooling-load reductions caused by shadowing are effective.

Notes: Abstract By the operation of research reactors, tritium-handling facilities, nuclear power plants, and a reprocessing facility around JAERI TOKAI, tritium is released into the environment in compliance with the regulatory standards. To investigate the levels of tritium concentration in environmental samples around JAERI, rain, air (vapor and hydrogen gas), and tissue-free water of pine needles were measured and analyzed from 1984 to 1993. Sampling locations were determined by taking into consideration wind direction, distance from nuclear facilities, and population distribution. The NAKA site (about 6 km west-northwest from the TOKAI site) was also selected as a reference point. Rain and tissue-free water of pine needles were sampled monthly. For air samples, sampling was carried out for two weeks by using the continuous tritium sampler. After the pretreatment of samples, tritium concentrations were measured by a low background liquid scintillation counter (detection limit is 0.8 Bq/l). Annual mean tritium concentrations in rain observed at six points for 10 years was 0.8 to 8.9 Bq/l, which decreased with distance from the nuclear facilities. Tritium concentrations in rain obtained at Chiba City were around 0.8 Bq/l (1987–1988) and those at the NAKA site were 0.8 to 3.8 Bq/l. Annual mean HTO concentrations in air at three points for 10 years were 9.2×10−2 to 1.1 Bq/m3, although HT concentrations in air, ranging from 1.7×10−2 to 5.8×10−2 Bq/m3, were not influenced by the operation of the nuclear facilities. Annual mean tritium concentrations in tissue-free water of pine needles at four points for 10 years were 1.4 to 31 Bq/l. Those at the NAKA site ranging from 1.4 to 6.2 Bq/l were in good agreement with the reported value by Takashima of 0.78 to 3.0 Bq/l at twenty-one locations in Japan. Monthly mean HTO concentrations in air for 10 years showed a good correlation with absolute humidity, while other samples showed no seasonal variation. Higher level tritium concentrations in rain, in air (vapor), and in tissue-free water of pine needles at the TOKAI site were caused by the tritium released from the nuclear facilities. The committed effective dose equivalent to the member of general public, estimated using the maximum tritium concentration in air (1.1 Bq/m3), was 0.23 μSv, which was about 1/4000 of dose limit for general public.