zero-powerhttp://www.oed.com/dictionary/zero-power_adj%3Ftab%3Dmeaning_and_usezero-power, adj.
Revised 2018

zero-poweradjective

Nuclear Physics.
  1. 1950–
    Designating a small nuclear reactor, usually built for research purposes, that develops so little power that no cooling and minimal shielding are required; = zero-energy adj.
    1. 1950
      Zero-power reactor, an experimental nuclear reactor operated at low neutron flux and at a power level so low that not only is no forced cooling required but also fission-product activity in the fuel is sufficiently low to allow the fuel to be handled after use without serious hazard.
      Nucleonics September 104/2
    2. 1983
      Plate versus pin geometry continues to be an issue for Zero-Power Plutonium Reactor (ZPPR) analysis.
      Transactions Amer. Nuclear Society vol. 44 528/2
    3. 2014
      It is a light-water zero-power pool-type reactor.
      Ann. Nuclear Energy vol. 71 91

Originally published as part of the entry for zero, n. & adj.

zero, n. & adj. was revised in June 2018.