| Autor: |
J.T. Mihalczo, T.A. Kniss, F.L. Glesius, J.A. Williams, C.W. Ricker |
| Rok vydání: |
1990 |
| Předmět: |
|
| Zdroj: |
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 299:187-190 |
| ISSN: |
0168-9002 |
| DOI: |
10.1016/0168-9002(90)90773-y |
| Popis: |
A high-sensitivity fission counter has been developed for subcriticality measurements by the 252Cf-source-driven neutron noise analysis method which requires two neutron counter channels. Performance specifications were provided by ORNL for spent light water reactor (LWR) fuel configurations where multiplication factors (k-values) could be as low as 0.85. A 3 × 3 array of 2 in. diameter, 8 ft long counters, fits into storage rack positions occupied by LWR fuel elements. Each counter consists of eight sensitive sections that contain a total of ∼18 g of 235U. Transmission-line technology is used to minimize capacitances and thus provides broad bandwidths. Each event in the fission counter produces two current pulses propagating in opposite directions on the transmission line. The differences in arrival times of the pulses at the ends of a counter determine the positions of the fission events. Tests on two fission counters show that each counter has a sensitivity of 12.5 cps/nvth and a position sensitivity with 1 ft resolution. Detection efficiency estimates for spent LWR fuel configurations indicate that, using two fission counters, subcriticality measurements can be made down to a k-value of 0.80: for two 3 × 3 counter arrays, to a k-value of 0.65. The 3 × 3 counter array or a single counter can be used in applications other than subcriticality measurements where position sensitivity, high sensitivity, and operability in high gamma fields are performance requirements. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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