Investigation of gamma radiation share in full SPND signal
21st Symposium of AER on VVER Reactor Physics and Reactor Safety (2011, Dresden, Germany)
Core design, monitoring and fuel management
Abstract
To fulfil the task of core linear power monitoring, software Hortica-M, as a part of
ICIS-M, only uses SPND signals and neutron-physics calculation to perform a construed
calculation of power of unmeasurable FAs. Confidence level of interpreting SPND signals to
great extent defines safe and efficient reactor operation.
Up to the present time, the share of reactor gamma radiation in full SPND signal was
assumed not to exceed one percent and not to depend on fuel enrichment and FA or SPND
burnup. Due to the difficulty of experimental estimation of gamma-radiation contribution to
SPND current, which exists nowadays, the paper gives a calculated estimation made with use
of up-to-date computer codes and constant libraries.
On the grounds of experimental data, the paper makes a conclusion about the
expedience of accounting reactor gamma radiation and dependence both on FA type and
burnup in FA and SPND in the conversion function from SPND current to the power density
of six rods surrounding SPND.