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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1995

Analytical investigation of the hygrothermal effects and parametric study of the Edge Crack Torsion (ECT) mode 3 test lay-ups

A shear deformation theory including residual thermal and moisture effects is developed for the analysis of either symmetric or unsymmetric laminates with mid-plane edge delamination under torsion loading. The theory is based on an assumed displacement field which includes shear deformation. The governing equations and boundary conditions are obtained from the principle of virtual work. The analysis of the (90/(+/- 45)(n)/(-/+ 45)(n)/90)(s) ECT mode 3 test lay-up indicates that there are no hygrothermal effects on the mode 3 strain energy release rate because the laminate, and both sublaminates above and below the delamination, are symmetric lay-ups. A further parametric study reveals that some other lay-ups can have negligible hygrothermal effects even when the sublaminates above and below the delamination are not symmetric about their own mid-planes. However, these lay-ups may suffer from distortion after the curing process. Another Interesting set of lay-ups investigated is a class of antisymmetric laminates with (+/-(theta/(theta -90)(2)/theta))(n) lay-ups. It is observed that when n takes on even numbers (2 and 4), both hygrothermal and mode 1 effects can be neglected. From this point of view, these lay-ups provide a way to determine the mode 3 toughness between two dissimilar layers. However, when n takes on odd numbers (1 and 3), both hygrothermal and mode 1 effects may be strong in these lay-ups. In particular, when theta equals 45 deg, the lay-ups are free from both hygrothermal and mode 1 effects irrespective of n.

Li, Jian↗
DOE OSTI2024

Evaluation of Apparent Metabolizable Energy and Apparent Ileal Amino Acid Digestibility of Spirulina (Arthrospira platensis) in Broiler Chickens and Laying Hens

Our study objective was to determine the apparent metabolizable energy (AME) and apparent ileal amino acid digestibility (AIAAD) of spirulina fed to broiler chickens and laying hens using the difference method. In both experiments, birds were either fed corn-soybean meal basal diets, containing no spirulina and formulated to provide the nutrient requirements of either broilers or layers, or fed test diets consisting of 25% spirulina and 75% of the appropriate basal diet. Titanium dioxide was added to all diets as an indigestible marker. The diets were fed to 10 replicate cages/treatment of broilers and 15 replicate cages/treatment of laying hens. The AME of spirulina for broilers was significantly lower (p < 0.05) (2368 ± 104 kcal/kg, as fed) than for laying hens (3144 ± 173 kcal/kg, as fed), suggesting bird type and age may influence energy utilization. The AIAAD of spirulina fed to broiler chickens did not differ from that of laying hens (p > 0.05), except for valine, alanine, and glycine, which were all significantly higher in laying hens (p < 0.05). Overall, the AIAAD for nonessential amino acids averaged 81.1%, with no significant difference between essential and nonessential amino acids. Differences in spirulina nutrient content cited in the literature support further research to determine the optimal inclusion of this alternative ingredient in broiler and layer diets.

Agriculture↗
DOE OSTI2022

Warmer incubation temperatures and later lay–orders lead to shorter telomere lengths in wood duck ( Aix sponsa ) ducklings

The environment that animals experience during development shapes phenotypic expression. In birds, two important aspects of the early-developmental environment are lay-order sequence and incubation. Later-laid eggs tend to produce weaker offspring, sometimes with compensatory mechanisms to accelerate their growth rate to catch-up to their siblings. Further, small decreases in incubation temperature slow down embryonic growth rates and lead to wide-ranging negative effects on many post-hatch traits. Recently, telomeres, non-coding DNA sequences at the end of chromosomes, have been recognized as a potential proxy for fitness because longer telomeres are positively related to lifespan and individual quality in many animals, including birds. Although telomeres appear to be mechanistically linked to growth rate, little is known about how incubation temperature and lay-order may influence telomere length. We incubated wood duck (Aix sponsa) eggs at two ecologically-relevant temperatures (34.9 and 36.2ºC) and measured telomere length at hatch and one week after. We found that ducklings incubated at the lower temperature had longer telomeres than those incubated at the higher temperature both at hatch and one week later. Further, we found that later-laid eggs produced ducklings with shorter telomeres than those laid early in the lay-sequence, although lay-order was not related to embryonic developmental rate. Furthermore, this study contributes to our broader understanding of how parental effects can affect telomere length early in life. More work is needed to determine if these effects on telomere length persist until adulthood, and if they are associated with effects on fitness in this precocial species.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1982

Structural dynamics of shroudless, hollow fan blades with composite in-lays

Structural and dynamic analyses are presented for a shroudless, hollow titanium fan blade proposed for future use in aircraft turbine engines. The blade was modeled and analyzed using the composite blade structural analysis computer program (COBSTRAN); an integrated program consisting of mesh generators, composite mechanics codes, NASTRAN, and pre- and post-processors. Vibration and impact analyses are presented. The vibration analysis was conducted with COBSTRAN. Results show the effect of the centrifugal force field on frequencies, twist, and blade camber. Bird impact analysis was performed with the multi-mode blade impact computer program. This program uses the geometric model and modal analysis from the COBSTRAN vibration analysis to determine the gross impact response of the fan blades to bird strikes. The structural performance of this blade is also compared to a blade of similar design but with composite in-lays on the outer surface. Results show that the composite in-lays can be selected (designed) to substantially modify the mechanical performance of the shroudless, hollow fan blade.

Aiello, R. A.↗
DOE OSTI2020

Materials Data on LaY(MnSi)4 by Materials Project

LaY(MnSi)4 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. La3+ is bonded in a body-centered cubic geometry to eight equivalent Si4- atoms. All La–Si bond lengths are 3.12 Å. Y3+ is bonded in a distorted body-centered cubic geometry to eight equivalent Si4- atoms. All Y–Si bond lengths are 3.06 Å. Mn+2.50+ is bonded to four Si4- atoms to form a mixture of edge and corner-sharing MnSi4 tetrahedra. There are two shorter (2.37 Å) and two longer (2.38 Å) Mn–Si bond lengths. There are two inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 9-coordinate geometry to four equivalent La3+, four equivalent Mn+2.50+, and one Si4- atom. The Si–Si bond length is 2.75 Å. In the second Si4- site, Si4- is bonded in a 9-coordinate geometry to four equivalent Y3+, four equivalent Mn+2.50+, and one Si4- atom. The Si–Si bond length is 2.50 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaY(MnSi)2 by Materials Project

LaY(MnSi)2 crystallizes in the tetragonal P4mm space group. The structure is three-dimensional. La is bonded in a 9-coordinate geometry to four equivalent Y, four equivalent Mn, and five Si atoms. All La–Y bond lengths are 3.88 Å. All La–Mn bond lengths are 3.01 Å. There are four shorter (3.13 Å) and one longer (3.39 Å) La–Si bond lengths. Y is bonded in a 9-coordinate geometry to four equivalent La, four equivalent Mn, and six Si atoms. All Y–Mn bond lengths are 2.88 Å. There are a spread of Y–Si bond distances ranging from 3.07–3.56 Å. Mn is bonded in a 4-coordinate geometry to two equivalent La, two equivalent Y, and four Si atoms. There are two shorter (2.36 Å) and two longer (2.37 Å) Mn–Si bond lengths. There are two inequivalent Si sites. In the first Si site, Si is bonded in a 4-coordinate geometry to one La, four equivalent Y, and four equivalent Mn atoms. In the second Si site, Si is bonded in a 4-coordinate geometry to four equivalent La, two equivalent Y, and four equivalent Mn atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaY(Co4B)2 by Materials Project

LaY(Co4B)2 crystallizes in the hexagonal P6/mmm space group. The structure is three-dimensional. La is bonded in a 6-coordinate geometry to two equivalent Y and six equivalent Co atoms. Both La–Y bond lengths are 3.43 Å. All La–Co bond lengths are 2.91 Å. Y is bonded in a 12-coordinate geometry to two equivalent La, twelve equivalent Co, and six equivalent B atoms. All Y–Co bond lengths are 2.90 Å. All Y–B bond lengths are 2.91 Å. There are two inequivalent Co sites. In the first Co site, Co is bonded in a distorted L-shaped geometry to two equivalent Y, two equivalent Co, and two equivalent B atoms. Both Co–Co bond lengths are 2.47 Å. Both Co–B bond lengths are 2.04 Å. In the second Co site, Co is bonded in a 12-coordinate geometry to three equivalent La and six equivalent Co atoms. B is bonded in a 6-coordinate geometry to three equivalent Y and six equivalent Co atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaY by Materials Project

LaY is beta-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are five inequivalent La sites. In the first La site, La is bonded to nine La and three equivalent Y atoms to form LaLa9Y3 cuboctahedra that share corners with six equivalent LaLa9Y3 cuboctahedra, corners with nine YLa3Y9 cuboctahedra, edges with nine YLa3Y9 cuboctahedra, edges with twelve LaLa9Y3 cuboctahedra, faces with seven YLa6Y6 cuboctahedra, and faces with twelve LaLa9Y3 cuboctahedra. There are six shorter (3.68 Å) and three longer (3.77 Å) La–La bond lengths. All La–Y bond lengths are 3.70 Å. In the second La site, La is bonded to six equivalent La and six Y atoms to form LaLa6Y6 cuboctahedra that share corners with six equivalent YLa3Y9 cuboctahedra, corners with nine LaLa6Y6 cuboctahedra, edges with nine LaLa6Y6 cuboctahedra, edges with twelve YLa6Y6 cuboctahedra, faces with six equivalent LaLa6Y6 cuboctahedra, and faces with thirteen YLa3Y9 cuboctahedra. All La–La bond lengths are 3.68 Å. There are three shorter (3.67 Å) and three longer (3.73 Å) La–Y bond lengths. In the third La site, La is bonded to nine La and three equivalent Y atoms to form LaLa9Y3 cuboctahedra that share corners with six equivalent YLa3Y9 cuboctahedra, corners with nine LaLa6Y6 cuboctahedra, edges with six equivalent YLa6Y6 cuboctahedra, edges with fifteen LaLa9Y3 cuboctahedra, faces with seven YLa3Y9 cuboctahedra, and faces with twelve LaLa9Y3 cuboctahedra. All La–La bond lengths are 3.68 Å. All La–Y bond lengths are 3.65 Å. In the fourth La site, La is bonded to six equivalent La and six Y atoms to form LaLa6Y6 cuboctahedra that share corners with six equivalent YLa3Y9 cuboctahedra, corners with nine LaLa9Y3 cuboctahedra, edges with nine LaLa9Y3 cuboctahedra, edges with twelve YLa3Y9 cuboctahedra, faces with six equivalent LaLa6Y6 cuboctahedra, and faces with thirteen YLa3Y9 cuboctahedra. All La–La bond lengths are 3.68 Å. There are three shorter (3.67 Å) and three longer (3.73 Å) La–Y bond lengths. In the fifth La site, La is bonded to six equivalent La and six Y atoms to form LaLa6Y6 cuboctahedra that share corners with six equivalent YLa3Y9 cuboctahedra, corners with nine LaLa9Y3 cuboctahedra, edges with nine LaLa9Y3 cuboctahedra, edges with twelve YLa3Y9 cuboctahedra, faces with six equivalent LaLa6Y6 cuboctahedra, and faces with thirteen YLa3Y9 cuboctahedra. All La–La bond lengths are 3.68 Å. There are three shorter (3.67 Å) and three longer (3.73 Å) La–Y bond lengths. There are four inequivalent Y sites. In the first Y site, Y is bonded to three equivalent La and nine Y atoms to form YLa3Y9 cuboctahedra that share corners with three equivalent LaLa9Y3 cuboctahedra, corners with twelve YLa3Y9 cuboctahedra, edges with nine LaLa9Y3 cuboctahedra, edges with twelve YLa3Y9 cuboctahedra, faces with six equivalent LaLa6Y6 cuboctahedra, and faces with thirteen YLa3Y9 cuboctahedra. There are three shorter (3.56 Å) and six longer (3.68 Å) Y–Y bond lengths. In the second Y site, Y is bonded to three equivalent La and nine Y atoms to form YLa3Y9 cuboctahedra that share corners with six equivalent YLa3Y9 cuboctahedra, corners with twelve LaLa6Y6 cuboctahedra, edges with six equivalent LaLa9Y3 cuboctahedra, edges with twelve YLa3Y9 cuboctahedra, faces with eight LaLa9Y3 cuboctahedra, and faces with twelve YLa3Y9 cuboctahedra. All Y–Y bond lengths are 3.68 Å. In the third Y site, Y is bonded to six La and six equivalent Y atoms to form YLa6Y6 cuboctahedra that share corners with six equivalent LaLa9Y3 cuboctahedra, corners with twelve YLa3Y9 cuboctahedra, edges with six equivalent YLa6Y6 cuboctahedra, edges with twelve LaLa6Y6 cuboctahedra, faces with seven YLa3Y9 cuboctahedra, and faces with thirteen LaLa9Y3 cuboctahedra. All Y–Y bond lengths are 3.68 Å. In the fourth Y site, Y is bonded to six La and six equivalent Y atoms to form YLa6Y6 cuboctahedra that share corners with six equivalent LaLa9Y3 cuboctahedra, corners with twelve YLa3Y9 cuboctahedra, edges with six equivalent YLa6Y6 cuboctahedra, edges with twelve LaLa9Y3 cuboctahedra, faces with seven YLa3Y9 cuboctahedra, and faces with thirteen LaLa9Y3 cuboctahedra. All Y–La bond lengths are 3.65 Å. All Y–Y bond lengths are 3.68 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaY by Materials Project

LaY crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. La is bonded to six equivalent La and six equivalent Y atoms to form LaLa6Y6 cuboctahedra that share corners with twelve equivalent LaLa6Y6 cuboctahedra, edges with twelve equivalent LaLa6Y6 cuboctahedra, edges with twelve equivalent YLa6Y6 cuboctahedra, faces with six equivalent LaLa6Y6 cuboctahedra, and faces with twelve equivalent YLa6Y6 cuboctahedra. All La–La bond lengths are 3.68 Å. All La–Y bond lengths are 3.66 Å. Y is bonded to six equivalent La and six equivalent Y atoms to form YLa6Y6 cuboctahedra that share corners with eighteen equivalent YLa6Y6 cuboctahedra, edges with six equivalent YLa6Y6 cuboctahedra, edges with twelve equivalent LaLa6Y6 cuboctahedra, faces with eight equivalent YLa6Y6 cuboctahedra, and faces with twelve equivalent LaLa6Y6 cuboctahedra. All Y–Y bond lengths are 3.68 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaY by Materials Project

LaY is beta-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are five inequivalent La sites. In the first La site, La is bonded to nine La and three equivalent Y atoms to form LaLa9Y3 cuboctahedra that share corners with six equivalent LaLa9Y3 cuboctahedra, corners with twelve YLa3Y9 cuboctahedra, edges with six equivalent YLa3Y9 cuboctahedra, edges with twelve LaLa9Y3 cuboctahedra, faces with eight YLa3Y9 cuboctahedra, and faces with twelve LaLa9Y3 cuboctahedra. There are six shorter (3.69 Å) and three longer (3.73 Å) La–La bond lengths. All La–Y bond lengths are 3.63 Å. In the second La site, La is bonded to six equivalent La and six Y atoms to form LaLa6Y6 cuboctahedra that share corners with six equivalent YLa3Y9 cuboctahedra, corners with twelve LaLa6Y6 cuboctahedra, edges with six equivalent LaLa6Y6 cuboctahedra, edges with twelve YLa3Y9 cuboctahedra, faces with seven LaLa6Y6 cuboctahedra, and faces with thirteen YLa3Y9 cuboctahedra. All La–La bond lengths are 3.69 Å. There are three shorter (3.60 Å) and three longer (3.67 Å) La–Y bond lengths. In the third La site, La is bonded to nine La and three equivalent Y atoms to form LaLa9Y3 cuboctahedra that share corners with three equivalent YLa3Y9 cuboctahedra, corners with twelve LaLa6Y6 cuboctahedra, edges with nine YLa3Y9 cuboctahedra, edges with twelve LaLa9Y3 cuboctahedra, faces with six equivalent YLa6Y6 cuboctahedra, and faces with thirteen LaLa9Y3 cuboctahedra. All La–La bond lengths are 3.69 Å. All La–Y bond lengths are 3.67 Å. In the fourth La site, La is bonded to six equivalent La and six Y atoms to form LaLa6Y6 cuboctahedra that share corners with six equivalent YLa3Y9 cuboctahedra, corners with twelve LaLa9Y3 cuboctahedra, edges with six equivalent LaLa6Y6 cuboctahedra, edges with twelve YLa3Y9 cuboctahedra, faces with seven LaLa9Y3 cuboctahedra, and faces with thirteen YLa3Y9 cuboctahedra. All La–La bond lengths are 3.69 Å. There are three shorter (3.60 Å) and three longer (3.67 Å) La–Y bond lengths. In the fifth La site, La is bonded to six equivalent La and six Y atoms to form LaLa6Y6 cuboctahedra that share corners with six equivalent YLa3Y9 cuboctahedra, corners with twelve LaLa9Y3 cuboctahedra, edges with six equivalent LaLa6Y6 cuboctahedra, edges with twelve YLa3Y9 cuboctahedra, faces with seven LaLa9Y3 cuboctahedra, and faces with thirteen YLa3Y9 cuboctahedra. All La–La bond lengths are 3.69 Å. There are three shorter (3.60 Å) and three longer (3.67 Å) La–Y bond lengths. There are four inequivalent Y sites. In the first Y site, Y is bonded to three equivalent La and nine Y atoms to form YLa3Y9 cuboctahedra that share corners with six equivalent LaLa9Y3 cuboctahedra, corners with nine YLa3Y9 cuboctahedra, edges with six equivalent LaLa6Y6 cuboctahedra, edges with fifteen YLa6Y6 cuboctahedra, faces with seven LaLa9Y3 cuboctahedra, and faces with twelve YLa3Y9 cuboctahedra. There are three shorter (3.54 Å) and six longer (3.69 Å) Y–Y bond lengths. In the second Y site, Y is bonded to six La and six equivalent Y atoms to form YLa6Y6 cuboctahedra that share corners with six equivalent LaLa9Y3 cuboctahedra, corners with nine YLa3Y9 cuboctahedra, edges with nine YLa3Y9 cuboctahedra, edges with twelve LaLa9Y3 cuboctahedra, faces with six equivalent YLa6Y6 cuboctahedra, and faces with thirteen LaLa9Y3 cuboctahedra. All Y–Y bond lengths are 3.69 Å. In the third Y site, Y is bonded to three equivalent La and nine Y atoms to form YLa3Y9 cuboctahedra that share corners with six equivalent YLa3Y9 cuboctahedra, corners with nine LaLa6Y6 cuboctahedra, edges with nine LaLa9Y3 cuboctahedra, edges with twelve YLa3Y9 cuboctahedra, faces with seven LaLa9Y3 cuboctahedra, and faces with twelve YLa3Y9 cuboctahedra. All Y–Y bond lengths are 3.69 Å. In the fourth Y site, Y is bonded to six La and six equivalent Y atoms to form YLa6Y6 cuboctahedra that share corners with six equivalent LaLa9Y3 cuboctahedra, corners with nine YLa3Y9 cuboctahedra, edges with nine YLa3Y9 cuboctahedra, edges with twelve LaLa9Y3 cuboctahedra, faces with six equivalent YLa6Y6 cuboctahedra, and faces with thirteen LaLa9Y3 cuboctahedra. All Y–La bond lengths are 3.67 Å. All Y–Y bond lengths are 3.69 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2022

The lay of the land: What we know about non-operating agricultural and absentee forest landowners in the U.S. and Europe

While non-operating agricultural and absentee forest landowners across the U.S. and Europe are an important group of landowners, our understanding of them remains relatively limited. In this paper, we conduct a systematic literature review on these landowners to encapsulate a current lay of the land in terms of what we know about these landowners and move the dialogue on this topic forward. Eighty-one articles are identified in our search of empirical literature. For each of the landowner types, we discuss their demographics and the three primary themes that emerged related to land management: participation in land management decisions, attitudes regarding land use and ownership, and resource needs in working with these landowners. For agricultural non-operating landowners, we find limited participation in land management decisions, particularly among women, a variety of individual and social factors play a role in involvement, and while they have pro-conservation attitudes, implementation of conservation practices is more limited. Absentee forest landowners we find are more willing to use management plans, yet less willing to engage in active management and risk reduction. These landowners have a range of attitudes regarding land use, with studies highlighting recreation, conservation, and profit motivations. In conclusion, our review concludes with identifying specific needs for more research and outreach on these landowners.

absentee↗
NASA NTRS1922

Laying Out of a Practical Air Route

Unfortunately the problem of laying out an air route has been approached by all who give it consideration as one of the hardest tasks in the world. Whereas, as a matter of fact, a very serviceable air route can be laid out with an absolute minimum of ground work.

Miner, V S↗
NASA NTRS2003

Developing A Contoured Deposition Head for In-Situ Tape Laying and Fiber Placement

A conformable compaction system employing three individual compactors has been designed for integration into fiber placement and tape laying deposition heads for out-of-autoclave fabrication of thermoplastic contoured parts. The compactors are intended to perform against two geometry specifications: (1) a general minimum radius of curvature limit of 180cm (71-in), and (2) a pad-up specification with a maximum height of 2.5mm (0.1-in) and a minimum ramp of 2.5mm (1-in). The mirrored specification is applicable to a pan-down. The three designs include a hot line compactor capable of a 1000N (400-lb) force at 450C over a 114mm (4.5-in) width, a hot area compactor capable of a 400N (100-lb) force at 450C over a 114mm width by 76mm length (4.5-in by 3-in), and a cold compactor that combines the features of a line and an area compactor. The cold compactor s line segments act with a 2800N (700-lb) force across a 127mm (5-in) width, while the cold compactor's area segments act with a 1000N (250-lb) force over a 127mm by 102mm (5-in by 4-in) area. Two of the designs, the hot line and hot area compactors, have been constructed, developed, and proven out in hot mode to compact actual thermoplastic composite plies over undulating geometry. IM-7PEEK [0/90/0/90]s pan-down and IM-7PEEK [0/-45/90/45]2s pad-up laminates have been fabricated and photomicrographs show good microstructure.

Lamontia, Mark A.↗
DOE OSTI2020

Challenges and Solutions in Operation and Lay-Up of the Modular Caustic- Side Solvent Extraction Unit - 20078

The Modular Caustic-Side Solvent Extraction (CSSX) Unit (MCU) was designed and constructed to provide interim salt waste processing so that the Liquid Waste Disposition Program (LWDP) could continue waste removal and tank closure until start-up of the Salt Waste Processing Facility (SWPF). MCU processes Clarified Salt Solution (CSS), or salt solution (SS) that has undergone actinide removal/filtration, to produce two waste streams: the cesium laden Strip Effluent (SE), which is incorporated into glass at the Defense Waste Processing Facility (DWPF), and the cesium depleted Decontaminated SS (DSS), which is incorporated into grout at the Saltstone Production Facility (SPF). MCU completed start-up in 2008 with an initial operating life of 3 years and design life of 5 years. Prior to reaching the end of the design life, multiple critical components were upgraded and/or replaced to mitigate risks associated with any delays in SWPF start-up. During the remainder of operation (until June 2019), MCU was challenged to maximize processing with minimal additional modifications to repair/improve aging infrastructure, while maintaining low levels of risk to workers and the environment. Notable challenges during the extended operating life of the facility involved both mechanical and operational issues. Two of the most significant issues were the increased frequency of Process Vessel Ventilation (PVV) High Efficiency Particulate Air (HEPA) filter change-outs and the biofouling of the SE coalescer (SEC). The major impacts of both issues were that replacement of these components 1) resulted in high exposure to workers, and 2) required substantial downtime, thus hindering achievement of processing goals. PVV HEPA filter replacements are required based on dose rate and differential pressure (dP) limits. After introducing a higher-curie feed to MCU, the operating time between change outs was reduced by approximately half. SEC replacements are required based on dP limits. After restarting from an extended outage, the operating life of the SEC was significantly reduced by more than half due to biofouling. As a result of extensive troubleshooting and process improvements, the facility was able to recover performance and extend the operating life of the PVV HEPA filters and the SEC media. Through troubleshooting both of these issues, the facility was also able to learn from prior experience and adapt in order to minimize down time and maintain throughput. Although the facility took advantage of short periods of downtime to perform nonintrusive troubleshooting and minor corrective/preventative maintenance activities, longer outages were periodically required for corrective maintenance involving process cell entry. During these outages, remote tools and specialized shield plates were employed to minimize dose to workers. Mock-ups of non-routine maintenance activities were critical to early identification of potential issues and improvements, which shortened outage duration. Consistent with the facility's operational strategy, evolutions needed for MCU layup were identified and sequenced to ensure safe conditions within the facility, meet pre-defined criteria for lay-up configuration, and protect workers, while minimizing the impact to SWPF integration. De-inventory and flushing of process areas was prioritized so that the total residual inventory was reduced as efficiently as possible. This paper discusses lessons learned and best practices from troubleshooting unique issues, performing complex maintenance activities, and implementing a layup strategy that best supports the overall system mission. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗