The effects of incorporation of selected biocides on physical and mechanical properties of aspen strandboard were assessed using five copper-based preservatives or zinc borate at three retention levels. Tebuconazole or 4,5-dichloro-2-N-octyl-4-isothiazolin-3-one (DCOI) were added as co-biocides to selective copper-based treatments. Mold box tests showed that only panels treated with DCOI...
In a Modular High Temperature Gas Reactor (MHGTR), the Pressurized Conduction Cooldown (PCC) event is an accident scenario in which there is a loss of forced convection of the coolant through the system but the pressure boundary remains intact. When the PCC event occurs, natural circulation onsets which results in...
Five U.S. high performance research reactors (HPRRs) are currently part of an international nonproliferation program with the objective of ultimately converting their highly enriched uranium (HEU) fuel to a new high density, low enriched uranium (LEU) fuel while still maintaining their reactor kinetic and thermal hydraulic performance. A uranium-molybdenum (U-Mo)...
In a Modular High Temperature Gas Reactor (MHTGR), the Depressurized Conduction Cooldown (DCC) event can be separated into three distinct stages: 1) depressurization, 2) air ingress and, 3) natural circulation. During normal operations, the HTGR utilizes forced convection to move the helium coolant through the reactor core. Thus, during normal...
The United States (US) Department of Energy (DOE) has identified the pebble-bed reactor as a high priority for US research with the end goal of licensing a pebble-bed reactor (PBR) for operation in the United States. Before this can be accomplished significant research must be done regarding the safety of...
Sodium cooled nuclear reactors are being considered for the next generation of nuclear power plants to provide clean electricity to the world. To prove the safety of these reactors, the fuel must be shown to safely handle large neutron fluxes that cause a spike in the thermal output of the...
The High Temperature Test Facility (HTTF) is an electrically heated, scaled model of a Modular High Temperature Gas Reactor (MHTGR). Five experiments were conducted to study Depressurized Conduction Cool-Down phenomena stemming from a Double-Ended Guillotine Break (DEGB). After a DEGB, the reactor pressure vessel would depressurize until the pressures are...
The development of pressure inside wood during preservative impregnation was studied using Douglas-fir heartwood and ponderosa pine sapwood. Pressure sensors mounted on sample holders provided the most reliable measurements. As expected, pressure equilibrated most rapidly with air as the treatment medium and ponderosa pine as the test species. Pressure changes...
Wood that is submerged in fresh water for long periods has increased permeability and other changed properties. Wood that is submerged in salt water may absorb considerable quantities of salts, which may render the wood resistant to microbial colonization. In this report, we describe decay tests on Douglas-fir sapwood and...
The effects of supercritical fluid (SCF) impregnation on physical properties of composites were investigated at various pressures, temperatures, and treatment times with carbon dioxide as the fluid and tebuconazole as a biocide. In general, within the ranges tested, SCF treatment had no negative effects on modulus of rupture (MOR), modulus...