CHARACTERIZATION OF AN ADVANCED GADOLINIUM NEUTRON ABSORBER ALLOY BY MEANS OF NEUTRON TRANSMISSION

Neutron transmission experiments were performed on samples of an advanced nickel-chromium-molybdenum-gadolinium (Ni-Cr-Mo-Gd) neutron absorber alloy. The primary purpose of the experiments was to demonstrate the thermal neutron absorbing capability of the alloy at specific gadolinium dopant levels. The new alloy is to be deployed for criticality control of highly enriched DOE SNF. For the transmission experiments, alloy test samples were fabricated with 0.0, 1.58 and 2.1 wt% natural gadolinium dispersed in a Ni-Cr-Mo base alloy. The transmission experiments were successfully carried out at the Los Alamos Neutron Science Center (LANSCE). Measured data from the neutron transmission experiments were compared to calculated results derived from a simple exponential transmission formula using only radiative capture cross sections. Excellent agreement between the measured and calculated results demonstrated the expected strong thermal absorption capability of the gadolinium poison and in addition, verified the measured elemental composition of the alloy test samples. The good agreement also indirectly confirmed that the gadolinium was dispersed fairly uniformly in the alloy and the ENDF VII radiative capture cross section data were accurate

NSNFP Activities in Support of Repository Licensing for Disposal of DOE SNF

The U.S. Department of Energy (DOE) Office of Civilian Radioactive Waste Management is in the process of preparing the Yucca Mountain license application for submission to the Nuclear Regulatory Commission as the nation’s first geologic repository for spent nuclear fuel (SNF) and high-level waste. Because the DOE SNF will be part of the license application, there are various components of the license application that will require information relative to the DOE SNF. The National Spent Nuclear Fuel Program (NSNFP) is the organization that directs the research, development, and testing of treatment, shipment, and disposal technologies for all DOE SNF. This report documents the work activities conducted by the NSNFP and discusses the relationship between these NSNFP technical activities and the license application. A number of the NSNFP activities were performed to provide risk insights and understanding of DOE SNF disposal as well as to prepare for anticipated questions from the regulatory agency

Nickel-based Gadolinium Alloy for Neutron Adsorption Application in Ram Packages

Neutron transmission experiments were performed on samples of an advanced nickel-chromium-molybdenum-gadolinium (Ni-Cr-Mo-Gd) neutron absorber alloy and chromium-nickel (Cr-Ni) stainless steel, modified by the addition of boron. The primary purpose of the experiments was to demonstrate the thermal neutron absorbing capability of the materials at specific gadolinium and boron dopant levels. The Ni-Cr-Mo-Gd alloy is envisioned to be deployed for criticality control of highly enriched U.S. Department of Energy (DOE)-owned spent nuclear fuel (SNF). For these transmission experiments, test samples were fabricated with 0.0, 1.58 and 2.1 wt% natural gadolinium dispersed in a Ni-Cr-Mo base alloy and 1.16 wt% boron in stainless steel. The transmission experiments were successfully carried out at the Los Alamos Neutron Science Center (LANSCE). Measured data from the neutron transmission experiments were compared to calculated results derived from a simple exponential transmission formula using total neutron cross sections. Excellent agreement between the measured and calculated results demonstrated the expected strong thermal absorption capability of the gadolinium and boron elements and in addition, verified the measured elemental composition of the Ni-Cr-Mo-Gd alloy and borated stainless steel test samples. The good agreement also indirectly confirmed that the size and distribution of the gadolinium in both the hot-top (as-cast) and Ni-Cr-Mo-Gd converted to plate was not a discriminator related to neutron absorption. Moreover, the Evaluated Nuclear Data File (ENDF VII) total neutron cross section data were accurate

The effectiveness of an ACT informed intervention for managing stress and improving therapist qualities in clinical psychology trainees

Objectives Clinical psychology trainees (CPTs) are vulnerable to high stress, which can adversely affect their personal and professional functioning. This study evaluated the effectiveness of a group acceptance and commitment therapy (ACT) informed stress management intervention for CPTs. Design Outcome measures were work-related stress, distress, life satisfaction, counseling self-efficacy, self-compassion, and therapeutic alliance. A cohort-controlled design, where an experimental group (n similar to= 28) was compared with a waitlist control group (n similar to= 28), was utilized, with a 10-week follow-up. Results Group comparisons showed statistically significant intervention effects for the main outcome measures, which were maintained at follow-up. Mediational analyses showed that changes on most outcomes were mediated by ACT mindfulness and acceptance processes. Conclusions Findings support the effectiveness of a group ACT program for CPTs regarding stress reduction and improving therapist qualities