This calculation uses regression (CLReg V1.0 computer code) and non-parametric statistical methods, as specified in References 1 and 12, to develop the critical limit for the 21 Pressurized Water Reactor (PWR) spent nuclear fuel (SNF) waste package (WP) in the proposed geologic repository at Yucca Mountain, Nevada. The critical limit is a limiting value of the effective neutron multiplication factor at which a WP configuration is considered potentially critical.

The purpose of this calculation is to establish the relative change in the effective neutron multiplication factor (k-eff) due to the use of MCNP unique identifiers used in the paper, Nuclear Criticality Calculations for Canister-Based Facilities - DOE SNF, that are different from the MCNP unique identifiers used in the paper, Analysis of Critical Benchmark Experiments and Critical Limit Calculation for DOE SNF.

The results of the MCNP criticality safety calculations described in this document are presented in Section 7.1. Based on the results presented attributes of the TAD canister-based systems that are important to ensuring their subcriticality are established. These attributes can be categorized according to the criticality control parameter that is impacted. Based on the categorization presented it is seen that moderation control is the underlying criticality control parameter for TAD canister-based systems containing CSNF with a maximum initial enrichment of 5 wt.% 235U/U.

The objective of this calculation is to evaluate the criticality potential for co-disposal waste packages affected by an igneous intrusion disruptive event in the emplacement drifts. The scope of this calculation is limited to U.S. Department of Energy (DOE) Spent Nuclear Fuel (SNF) types in DOE standardized SNF canisters or Multi-Canister Overpack (MCO) Canisters.

The purpose of this calculation is to perform waste-form specific nuclear criticality safety calculations to aid in establishing criticality safety design criteria, and to identify design and process parameters that are potentially important to the criticality safety of Department of Energy (DOE) standardized Spent Nuclear Fuel (SNF) canisters. It is intended that the results of the criticality safety calculations provided in this document will

The objective of this calculation is to characterize the nuclear criticality safety concerns
associated with the codisposal of the Department of Energy’s (DOE) Enrico Fermi (EF) Spent
Nuclear Fuel (SNF) in a 5-Defense High-Level Waste (5-DHLW) Waste Package (WP) and
placed in a Monitored Geologic Repository (MGR). The scope of this calculation is limited to
the determination of the effective neutron multiplication factor (keff) for the degraded mode
internal configurations of the codisposal WP. The results of this calculation and those of Ref. 8

The objective of this analysis is to characterize a codisposal canister containing MIT or ORR fuel in the Five-Pack Defense High-Level Waste (5-DHLW) Waste Package (WP) to demonstrate concept viability related to use in the Mined Geologic Disposal System (MGDS) environment for the postclosure time frame. The purpose of this analysis is to investigate the disposal criticality and shielding issues for the DHLW WP and establish DHLW WP and codisposal canister compatibility with the MGDS, and to provide criticality and shielding evaluations for the preliminary DHLW WP design.

The objective of these calculations is to perform intact and degraded mode criticality evaluations of the Department of Energy's (DOE) Fort Saint Vrain (FSV) commercial High Temperature Gas Reactor (HTGR) spent nuclear fuel. This analysis evaluates codisposal in a 5-Defense High-Level Waste (5-DHLW/DOE SNF) Long Waste Package (WP)(CRWMS M&O 2000c, Attachment V), which is to be placed in a potential monitored geologic repository (MGR).