Columbia, Yes still using the ASP-1/NRD probe.
In addition to what Fred was saying - another big factor is gamma rejection. Basically, there is no meter indication in gamma fields up to 1 rem/hr (and probably even higher). Where as many of the other lighter neutron meters have problems when any gamma fields are present and with our plant typically where we have neutrons (e.g., Drywell) we would also have high gamma fields up to 200-500 mrem/hr. Michael Kinmark Columbia Generating Station
