The purpose of this activity is to develop a representative “limiting” axial burnup profile for pressurized water reactors (PWRs), which would encompass the isotopic axial variations caused by different assembly irradiation histories, and produce conservative isotopics with respect to criticality. The effect that the low burnup regions near the ends of spent fuel have on system reactivity is termed the “end-effect”. This calculation will quantify the end-effects associated with Pressurized Water Reactor (PWR) fuel assemblies emplaced in a hypothetical 21 PWR waste package.

The purpose of this calculation is to develop axial profiles for estimating the axial variation in burnup of a boiling water reactor (BWR) assembly spent nuclear fuel (SNF) given the average burnup of an assembly. A discharged fuel assembly typically exhibits higher burnup in the center and lower burnup at the ends of the assembly. Criticality safety analyses taking credit for SNF burnup must account for axially varying burnup relative to calculations based on uniformly distributed assembly average burnup due to the under-burned tips.

WCS Presentation slides for NRC meeting held 8-22-16 to discuss the status of responses to NRC Requests for Supplemental Information.

The purpose of this activity is to develop a representative “limiting” axial burnup profile for pressurized water reactors (PWRs), which would encompass the isotopic axial variations caused by different assembly irradiation histories, and produce conservative isotopics with respect to

This calculation compares results from criticality evaluations for a 21-assembly pressurized water reactor (PWR) waste package based on 12 axial burnup profile representations for commercial spent nuclear fuel (SNF) assemblies. The burnup profiles encompass the axial variations caused by different fuel assembly irradiation histories in a commercial PWR, including end effects, and the concomitant effect on reactivity in the waste package. The bounding axial burnup profiles in Table T of reference 6.3 are used for this analysis.

These slides were presented by Waste Control Specialists LLC (WCS) to the NRC at the June 16, 2015 pre-application public meeting at the NRC offices in Rockville, Maryland.

In 1999, the United States Nuclear Regulatory Commission (U.S. NRC) initiated a research program
to support the development of technical bases and guidance that would facilitate the implementation of burnup
credit into licensing activities for transport and dry cask storage. This paper reviews the following major areas of
investigation: (1) specification of axial burnup profiles, (2) assumption on cooling time, (3) allowance for
assemblies with fixed and removable neutron absorbers, (4) the need for a burnup margin for fuel with initial

WASHINGTON, D.C. (April 28, 2016) – Waste Control Specialists LLC (WCS) submitted an application to the Nuclear Regulatory Commission (NRC) for a license to construct and operate a Consolidated Interim Storage Facility (CISF) for used nuclear fuel. The filing comes after a year of pre-application meetings with NRC and maintains the timeline WCS outlined in February 2015.

The application is being led by WCS, along with its partners AREVA and NAC International, both global industry leaders in the transportation and storage of used nuclear fuel.

By letter dated April 28, 2016, Waste Control Specialists, LLC (WCS) submitted a specific
license application under 10 CFR Part 72 requesting authorization to construct and operate a
Consolidated Interim Storage Facility for Spent Nuclear Fuel and Reactor-Related Greater Than
Class C Low-Level Waste in Andrews County, Texas. The Nuclear Regulatory Commission
(NRC) performed an acceptance review of the application to determine if the application
contains sufficient technical information to allow the NRC staff to complete the detailed technical

All of the pieces for the Waste Control Specialists (WCS) Safety Analysis Report (SAR) and Environmental Report (ER).