A digital, wide-range, neutron detection (WRND) system in a compact, VME form factor monitors neutron activity within the core of a nuclear reactor across the reactor’s entire operating range, from 1.0 n/cm2/s up to 1010 n/cm2/s. This allows for a reduction in the complexity of space-based nuclear instrumentation systems, as a single instrument can be used instead of requiring different instrumentation for each of the operation ranges of the reactor (start-up, ramp-up, and nominal power).

This instrument consists of one or more fission chamber detectors, an integrated electronics module, and interconnected cabling, all of which are adapted for the space environment from proven, terrestrial-based technology. WRND delivers logarithmic output signals to a host system, proportional to neutron flux and rate across the entire operating range of the reactor. The electronics module hardware and firmware are the basis of the innovation.

WRND is broadly compatible with many potential future applications (nuclear power, nuclear propulsion, etc.). Nothing in the initial design assumes a particular type of reactor, or whether it will be vehicle- or land-based. This innovation’s ability to function over a wide range of neutron fluxes ensures its development is not necessarily linked with any particular reactor type, and in no way limits future nuclear power implementation options, while still providing NASA with the needed functionality.

This work was done by John F. Merk of Aurora Flight Sciences and Alberto Busto of Black River Technology for Glenn Research Center.

Inquiries concerning rights for the commercial use of this invention should be addressed to NASA Glenn Research Center, Innovative Partnerships Office, Attn: Steve Fedor, Mail Stop 4–8, 21000 Brookpark Road, Cleveland, Ohio 44135. LEW-18469-1