Optimal Sampling Plans for Inventory Verification of Spent Fuel Ponds

Volume: 58, June 2019, pages 3-12,

Authors: Thomas Krieger¹, Katharina Aymanns¹, Arnold Rezniczek², Irmgard Niemeyer¹

¹_{Forschungszentrum Jülich GmbH,} ²_{UBA GmbH}

Abstract:Spent fuel unloaded from the reactor core of Light Water Reactors is usually stored in the spent fuel pond of the reactor. The IAEA and EURATOM have a number of different instruments in their verification instrument portfolios to verify spent fuel assemblies in the spent fuel pond. Depending on the situation, e.g., the type of the different fuel assemblies’ strata and the accessibility for future re-verification, different requirements for the verification exist.

Once spent fuel has been loaded into dry storage casks for transport and intermediate storage, it becomes difficultto- access. The IAEA requires that nuclear material prior to its becoming difficult-to-access must be verified using sampling plans that provide a high detection probability for a possible diversion of nuclear material from the spent fuel assemblies.

The paper discusses how to set up optimal sampling plans depending on the verification instruments, the assumed detection capabilities of these verification instruments, and the presumed diversion strategies.

Keywords: sampling plans; detection probability; inventory verification; spent fuel ponds; difficult-to-access.

Reference guideline:

Krieger, T., Aymanns, K., Rezniczek, A., & Niemeyer, I. (2019). Optimal Sampling Plans for Inventory Verification of Spent Fuel Ponds. ESARDA Bulletin - The International Journal of Nuclear Safeguards and Non-proliferation, 58, 3-12. https://doi.org/10.3011/ESARDA.IJNSNP.2019.1