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DOE OSTI2021

Preliminary Studies of UV Photolysis of Gas-phase CH3I in Air: Time-resolved Infrared Identification of Methanol and Formaldehyde Products

Halogen-bearing compounds are known to photolyze under UV radiation; analysis of degradation products is of interest for both safety and environmental considerations. Time-resolved infrared spectroscopy was used in the laboratory to study the UV-photolysis of methyl iodide. Photolysis products methanol (CH3OH) and formaldehyde (HCHO) were clearly identified in a time-resolved manner. Preliminary kinetic models predict the formation of both CH3OH and HCHO.

Hughey, Kendall D.↗

DOE OSTI2019

Xenon collection method and system

A method and system for collecting xenon (Xe) is described. A microchannel heat exchanger is used in combination with a mechanical cooler and an absorbent. A combination of components makes up a Xe Collection Subsystem that is adapted for use in an efficient process for collecting, purifying, and measuring Xe isotopes collected from air as part of the International Monitoring System.

Hayes, James C.↗

DOE OSTI2018

Requirements for Xenon International (Rev. 2)

This document defines the requirements for the new Xenon International radioxenon system. The output of this project will be a Pacific Northwest National Laboratory (PNNL) developed prototype and a manufacturer-developed production prototype. The two prototypes are intended to be as close to matching as possible; this will be facilitated by overlapping development cycles and open communication between PNNL and the manufacturer.

61 RADIATION PROTECTION AND DOSIMETRY↗

DOE OSTI2018

Xenon collection method and system

A method and system for collecting xenon (Xe) is described. A microchannel heat exchanger is used in combination with a mechanical cooler and an absorbent. A combination of components makes up a Xe Collection Subsystem that is adapted for use in an efficient process for collecting, purifying, and measuring Xe isotopes collected from air as part of the International Monitoring System.

Hayes, James C.↗

DOE OSTI2015

Requirements for Xenon International

This document defines the requirements for the new Xenon International radioxenon system. The output of this project will be a Pacific Northwest National Laboratory (PNNL) developed prototype and a manufacturer-developed production prototype. The two prototypes are intended to be as close to matching as possible; this will be facilitated by overlapping development cycles and open communication between PNNL and the manufacturer.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

DOE OSTI2012

TECHNOLOGY GOALS FOR A NEXT GENERATION RADIOXENON MONITORING SYSTEM

The Swedish Automated/Unattended Noble Gas Analyzer (SAUNA) is a nuclear explosion monitoring technology that was developed to provide continuous field measurement of radioxenon gas escaping from an underground nuclear detonation. This capability is a key to the verification of the Comprehensive nuclear Test Ban Treaty (CTBT). While the SAUNA technology has demonstrated success in the field, a decade of operation primarily in the International Noble Gas Experiment (INGE) has yielded areas for improvement in operations and verification. These opportunities include measurement sensitivity, sample throughput time, system uptime, and data availability. Increasing measurement sensitivity allows for finer discrimination between manmade radioxenon signals (from sources such as medical isotope production facilities) and radioxenon signals that result from fission in a nuclear weapon. Measurement sensitivity can be increased with techniques such as halving the sample processing time or increasing the quantity of xenon extracted from the atmosphere. Additionally, improvements in gas processing technology and control system software can improve the uptime and data availability. This paper will discuss the technical requirements as well as the system and operational specifications which we expect to be the groundwork for the next-generation of radioxenon monitoring systems.

Ely, James H.↗

DOE OSTI2012

A TREATMENT OF THE MEASUREMENT UNCERTAINTY FOR XENON VOLUME QUANTIFICATION

Treaty monitoring gas measurement systems that measure radioxenon typically report results as an activity concentration, which is the measured radioxenon activity divided by the amount of stable xenon present. While the nuclear activity uncertainty has been studied in detail and is driven primarily by counting statistics, the uncertainty for the volume measurement has been considered in less detail. A framework for a more complete consideration of the uncertainty for the volume measurement has been developed. This type of analysis can help drive the system requirements for the volume quantification while the system is still being developed or added to advanced fielded systems. Depending on the accuracy requirements for the activity concentration, the volume quantification measurement and analysis can be developed to a suitably high level of accuracy. Nominally, it is best to have the activity concentration uncertainty limited by the uncertainty of the activity measurement because it tends to be fundamentally limited by the counting statistics. Volume quantification should be performed more accurately so that the activity concentration uncertainty is not degraded from the counting statistics. This paper will describe in detail a stable gas quantification uncertainty analysis for a xenon monitoring system.

Harper, Warren W.↗