IMPROVEMENTS IN NUCLEAR REACTORS PROVIDED WITH A NEUTRON FLUX MEASUREMENT DEVICE
Measurement of low level neutron flux in a reactor is difficult partly because of gamma emission following shutdown, and partly because the measuring apparatus has to be so near the reactor that it is liable to be destroyed when the reactor starts up again. This invention aims to overcome these drawbacks by interposing between the core and the measurement device, which may be of any type, a shield, preferably of bismuth, which has a high mass coefficient for gamma rays, low neutron cross section and does not cause secondary gammas. For normal operation, when flux levels are high, a retractable shield can be interposed between the bismuth shield and the reactor. This must have a large neutron cross section and must give rise to practically no secondary gammas. Boron is the preferred material for this. The measuring instrument has two calibrations corresponding to the two positions of the retractable shield. (auth)
- Research Organization:
- Originating Research Org. not identified
- NSA Number:
- NSA-12-000700
- OSTI ID:
- 4330710
- Journal Information:
- Nuclear Power, Journal Name: Nuclear Power Vol. 2; ISSN 0546-8981; ISSN NUPOAS
- Country of Publication:
- United Kingdom
- Language:
- English
Similar Records
Method and device for the passive protection of a nuclear reactor
ANALYSIS OF THE RECENT TSF SECONDARY GAMMA-RAY EXPERIMENT