Radionuclide Inventory

The inventory of radionuclides in a reactor core during operation or after shutdown gives a fair amount of information about the reactor core, therefore nuclear inventories are classified and inaccessible. [1] The On-line inventory is the current inventory in the core.[2] You can use a core model and operating time to determine the radionuclide inventory[1]. the radionuclide inventory can show the type of fuel used as well as its burn-up, which is how much energy has been extracted.[1] Different reactor designs and fuel cycles give characteristic signatures in the inventory.[1] The quantity of certain radionuclides can reveal the power level and history of the reactor, including changes in power output, and periods of shutdown.[1] The neutron spectrum can determine if the reactor is a fast reactor or a thermal reactor.[1] The radionuclides that are formed through moderator and coolant interactions can give off a specific signature. Tritium formation can indicate heavy water as a moderator or coolant as in CANDU reactors.[1]. The inventory may include a soil sample from a nuclear power plant. The thermal load of long-lived radionuclides are important for the disposal of spent fuel.[2] For severe accidents, the activity of the released material is essential.[2] The inventories depend on the irradiation time and decay time for a given unit mass of fuel for each reactor type.[2] For reactors that operate in continuous fueling mode the inventory can be estimated from the average burnup of the core and the decay time(cooling time)..[2]
$$I_{tot}=I(bu_{avg}, \text{ decay time})\times m_{fuel}$$

[[CANDU Reactor]]
[[ORIGEN2]] – used to calculate nuclide inventories
[[Inventory for Periodic Fuel Charging Reactors]]

Sources

  • [1] S. Høibråten et al.ENVIRONMENTAL RISK ASSESSMENT FOR NON-DEFUELLED, DECOMMISSIONED NUCLEAR SUBMARINES. 2007. doi: 10.13140/RG.2.1.1660.7124.
  • [2] R. Pöllänen, H. Toivonen, J. Lahtinen, and T. Ilander, “OTUS – Reactor Inventory Management System Based on ORIGEN2,” 1995.

Backlinks

[[Criticality Accident]]
[[Fast Reactor]]
[[Interpolation]]
Liquid Metal Reactors
[[Neutron Moderators]]
[[Radionuclide]]
[[Tritium]]