| 摘要 |
PURPOSE:To monitor radioactive iodine in an exhaust gas continuously and automatically, by arranging a rare gas purging section downstream from a filter chamber and upstream from a measuring section to remove a radioactive rare gas trapped in a sheet-like filter passing through the filter chamber. CONSTITUTION:A long-sized sheet-like filter 11 consisting of a iodine trapping material made of activated carbon fiber or the like is pinched securely between a filter chamber 10 and a rare gas purging section 14. A sample gas is made to pass through the filter chamber 10 for a fixed time to be trapped. A gas trapped portion of the sheet-like filter 11 is transferred to the rare gas purging section 14. After a fixed time of a purging process, the gas purged portion is transferred to a measuring section 15 to measure a radiation dose. During transfer, a new portion of the filter 11 is delivered from a winding roll 12 to continue trapping. Thus, radioactive iodine in the exhaust gas which is expected to be mixed with a radioactive rare gas such as Kr 85 can be monitored continuously and automatically.
|
