In general, a liβuid scintillation method can be applied to determine the tritium concentration in an environmental water such as rain water and river one. In this case, the followings are generally carried out: (1) a sample solution is directly measured in a large vial for long time (about several days) by using a low-back liβuid scintillation counter; (2) after the sample solution is enriched by applying the electrolysis method, the solution thus enriched is measured with a normal liβuid scintillation counter. However, the tritium separation factor (βa) in the solution obtained by the electrolysis-apparatus having a film of solid polymer electrolyte by applying the electrolysis method (SPE electrolysis method) is not so large (about 6) . Increasing βa in the solution is an important matter since it leads to an increase in the accuracy of tritium concentration in an environmental water. We then considered the effect of a high magnetic field on the electrolysis, the electrolysis-apparatus based on the SPE electrolysis method was set in the field, and the electrolysis was carried out under each high magnetic field in the range of 0-3 T. The electrolysis-apparatus was set as follows: the direction of the electrolysis current was at (a) right angle, (b) counter current, (c) reverse current, to the magnetic field. Conseβuently, the following three were obtained : in the case of (a), βa increased with increasing the magnetic field between 0 and 2 T (0-2 T), but decreased with increasing one (2-3 T) ; in that of (b), a increased with increasing the magnetic field (0-3 T), and especially, exponentially increased (2-3 T) ; in (c), βa slightly increased (0-3 T) . From the above-mentioned, the following two matters were clarified: (1) the effect of the magnetic field on the electrolysis is fairly large under a certain condition ; (2) a large βa can be obtained when an appropriate condition is chosen.
A procedure was established for the detection of irradiated chicken by GC/FID analysis of2- alkylcyclobutanones (RCBs) and hydrocarbons (HCs) using cleanup by Soxhlet extraction and Florisil chromatography. Fat extract was obtained from irradiated chickens by a Soxhlet apparatus. A concentrated fat extract containing200 mg of fat with 2 μg of n-eicosane as internal standard (IS) was applied to Florisil columns, which were deactivated by adding 17parts of water to 100 parts of adsorbent. The HCs were eluted in 60 ml of n-hexane. This eluate was concentrated and analyzed by GC/FID. After 150ml of n-hexane was eluted from the same column, RCBs were eluted with 120ml of 1% diethyl ether solution in n-hexane. This eluate was concentrated to 0.2ml and 0.1μg of 2-cyclohexylcyclohexanone (IS) was added to the mixture, which was analyzed by GC/FID. This process rendered it possible to detect HCs and RCBs efficiently and simultaneously. HCs and RCBs were detected in chicken meat irradiated at 0.5 kGy by GC/FID.
In order to understand influences of main meteorological parameters upon indoor radon levels, the following parameters were simultaneously measured for 48 h : indoor radon concentration, temperature, relative humidity, precipitation, and wind velocity in an experimental one-floor concrete building at the National Institute of Radiological Sciences, Chiba. A typhoon passed nearby during the observation period The radon concentration ranged from 28.1-218.6 Bq m-3 with an arithmetic mean of 103.1 Bq m-3 and a geometric mean of 89.8 Bq m-3. Arithmetic means of temperature, relative humidity, precipitation, and air pressure during the observation period were 25.6°C, 88%, 42.9 mm, and 996.3 hPa, respectively. The regression analysis indicates that the relative humidity, air pressure, and water in soil at depth of 90 cm were estimated to be more effective factors to influence the radon concentration in air than others.
We applied an ozone generator to sterilize and to deodorize the waste water from radioisotope facilities. A small tank connected to the generator is placed outside of the drainage facility founded previously, not to oxidize the other apparatus, The waste water is drained 1 m3at a time from the tank of drainage facility, treated with ozone and discharged to sewer. All steps proceed automatically once the draining work is started remotely in the office. The waste water was examined after the ozone treatment for 0 (original), 0.5, 1.0, 1.5 and 2.0 h. Regarding original waste water, the sum of conform groups varied with every examination repeated probably depend on the colibacilli used in experiments; hydrogen sulfide, biochemical oxygen demand and the offensive odor increased with increasing coliform groups The ozone treatment remarkably decreased hydrogen sulfide and the offensive odor, decreased coliform groups when the original water had rich coliforms.