Automated In-Vessel Neutron Flux Detector System Embedded in Control Drum Assembly
A measurement device for determining a power level of a nuclear reactor core is provided, the measurement device comprising an in-vessel detector assembly. The in-vessel detector assembly comprises a rotatable housing defining a cavity therein and a detector element positioned in a first angular portion of the cavity of the housing. A control drum for a nuclear reactor core and a system for monitoring a power level of a nuclear reactor are also provided.
1 . A measurement device for determining a power level of a nuclear reactor core, the measurement device comprising:
an in-vessel detector assembly comprising:
a housing defining a cavity therein, wherein the housing is configured to be rotatable in place, wherein the cavity of the housing comprises a first angular portion, and wherein a rotational range of the housing is comprised of a number of angular sectors; and
a detector element positioned in the first angular portion of the cavity of the housing, wherein the detector element is configured to be responsive to a neutron flux upon an angular displacement of the first angular portion towards a first angular sector of the rotational range.
2 . The measurement device as claimed in claim 1 , wherein the in-vessel detector assembly is configured to remain within a cavity of the nuclear reactor core for the duration of a planned lifetime of a fuel assembly of the nuclear reactor core.
3 . The measurement device as claimed in claim 2 , wherein the nuclear reactor is a microreactor.
4 . The measurement device as claimed in claim 2 , wherein the in-vessel detector assembly is configured to remain within the cavity of the nuclear reactor core for about 8 years or longer.
5 . The measurement device as claimed in claim 1 , wherein the rotational range of the housing is about 180 degrees or more.
6 . The measurement device as claimed in claim 1 , wherein the detector element is embedded in the housing.
7 . The measurement device as claimed in claim 1 , wherein the housing comprises a neutron absorber, wherein the neutron absorber is positioned within the first angular portion of the housing.
8 . The measurement device as claimed in claim 7 , wherein the detector element is attached to the neutron absorber.
9 . The measurement device as claimed in claim 7 , wherein the detector element is embedded in an outermost radial portion of the neutron absorber.
10 . The measurement device as claimed in claim 1 , wherein the detector element is configured to be responsive to a source range neutron flux, an intermediate range neutron flux, or a combination thereof.
11 . The measurement device as claimed in claim 1 , wherein the in-vessel detector assembly is configured to shield the detector element from a neutron flux upon a rotation of the housing to align the first angular portion of the cavity of the housing with a second angular sector of the rotational range.
12 . The measurement device as claimed in claim 1 , wherein the housing is configured to be rotated by a drive for a control drum of the nuclear reactor.
13 . A control drum for a nuclear reactor core, the control drum comprising:
a rotatable housing comprising a neutron absorber section, wherein the rotatable housing is configured to rotate within a rotational range comprised of a number of angular sectors, and wherein the neutron absorber section is positioned within a first angular portion of the rotatable housing; and
one or more detector elements configured to be responsive to a neutron flux, wherein the one or more detector elements are housed within the first angular portion of the rotatable housing.
14 . The control drum as claimed in claim 13 , wherein the one or more detector elements is affixed to the neutron absorber section.
15 . The control drum as claimed in claim 14 , wherein the control drum comprises a plurality of detector elements axially distributed along a length of the neutron absorber section.
16 . The control drum as claimed in claim 13 , wherein the one or more detector elements is embedded into an outer surface of the neutron absorber section.
17 . The control drum as claimed in claim 16 , wherein the one or more detector elements are flush with the outer surface of the neutron absorber section.
18 . A system for monitoring a power level of a nuclear reactor, the system comprising:
a plurality of in-vessel detector assemblies, wherein:
each of the in-vessel detector assemblies comprises a neutron flux detection portion responsive to a source range neutron flux, an intermediate range neutron flux or a combination thereof; and
each of the in-vessel detector assemblies is independently configured to be rotated in place through a rotational range by a control drum drive of the nuclear reactor, each rotational range comprising a number of angular sectors; and
wherein the system is configured to independently determine a rotation of each of the in-vessel detector assemblies based on a neutron flux level within the nuclear reactor, wherein a rotation of an in-vessel detector assembly comprises an alignment of the neutron flux detection portion thereof with one of the angular sectors of the rotational range of the in-vessel detector assembly.
19 . The system as claimed in claim 18 , wherein the system comprises:
at least one in-vessel detector assembly comprising a source range neutron flux detection portion; and
at least one in-vessel detector assembly comprising an intermediate range neutron flux detection portion.
20 . The system as claimed in claim 18 , wherein each of the plurality of in-vessel detector assemblies is configured as an instrumented control drum, wherein each in-vessel detector assembly comprises a neutron absorber, and wherein each of the neutron flux detection portions is embedded in an outer radial surface of the neutron absorber.