| 摘要 |
<p>A device for detecting the presence of a cooling medium at certain levels and for detecting the density of the cooling medium in a reactor tank (1). The device includes a radioactive source (9, 12, 39) disposed outside the reactor tank and having its radiation directed right through the reactor tank. Furthermore, at the opposite side of the reactor tank and outside the latter a detector device (10) is disposed for detecting the radiation from the radioactive source transmitted through the reactor tank. A comparison circuit (22) compares the detected radiation with the radiation emitted by the radioactive source. The radiation of the radioactive source has a pulse structure and its energy exceeds the energy of the radiation which is emitted from the reactor core (2) and other parts of the reactor plant. Several measures are taken for collimating the beam at the different levels.</p> |
