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Site-Directed Research and Development (SDRD)


Started in 2002 by Congressional authorization, the Site-Directed Research and Development (SDRD) Program is an essential element of the NNSS technical enterprise. The SDRD program is our premier science and technology venue and primary source for discovery and innovation for NNSS national security missions. Similar to the laboratory-directed research and development (LDRD) programs at the NNSA National Laboratories and production plants, SDRD enhances the technical vitality of the NNSS by addressing the following core areas:

  • developing and demonstrating innovative ideas and technologies to advance new solutions to national and global security needs;
  • enhancing core competencies required for current and emerging technical missions; and
  • retaining and recruiting individuals with critical skills.

Proposals are solicited every year and about two dozen projects tied to principal thrust areas are funded annually. An annual report is released every April for the previous year’s projects.


SDRD Highlights


NNSS' Ajanaé Williams named Senator Jacky Rosen’s December 2022 Nevada Woman in STEM

headshot of Ajanaé Williams
Ajanaé Williams

Congratulations to Ajanaé Williams, a scientist on the Computing and Data Science team, on receiving Senator Jacky Rosen’s Nevada Women in STEM award this December! Every month, Senator Rosen’s office highlights a woman in STEM who has made outstanding contributions in their field.

Born and raised in Las Vegas, Ajanaé realized her love for computers and science early on in her life. While studying computer science at the University of Nevada, Las Vegas (UNLV), Ajanaé was awarded UNLV’s African American Scholar Award and a Millennium Scholarship for her studies. As a scientist at NNSS, Ajanaé is part of the experimental process from start to finish, from software development to setting up detector systems and fielding experiments. She inspires girls and young women throughout Nevada to enter STEM fields and break expectations of what “a scientist looks like”—instead of a lab coat, Ajanaé wears a hard hat to work!

Visit Senator Rosen’s Nevada Women in STEM webpage to learn more about the award and past award recipients.

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SDRD projects win R&D 100 awards

R&D 100 awards logo

Many projects the NNSS submits to the prestigious R&D 100 awards get their start as SDRD projects. From feasibility studies to exploratory research, SDRD allows scientists and engineers to engage in cutting-edge research and technology in global security and stockpile stewardship. All five of the NNSS projects that were finalists or winners since 2017 have their roots in SDRD. In fact, our most recent winner, the “X-Ray Polarizing Beam Splitter (XRPBS)” project, began as an SDRD in 2018.

Principal Investigator Radu Presura began the two-year SDRD project “Single-Crystal X-Ray Spectropolarimeter” with researchers from Sandia, Los Alamos, Argonne, and the Special Technologies Lab. This work led to XRPBS, the first X-ray polarizing beam splitter in existence. Using a single cubic crystal, the XRPBS separates an incoming X-ray beam into two linearly polarized beams with mutually orthogonal polarizations, enabling the measurement of both components simultaneously. This technology can be used for plasma diagnostics and analyzing the linear polarization state of an X-ray beam.

XPBRS Instrument
XPBRS instrument | Closeup of the XRPBS

The idea was born out of an observation that plasmas could be better characterized if the polarization of emitted X-rays could be measured. There are many exciting opportunities for the XRPBS on multiple testbeds across the National Security Enterprise. One application that Presura plans to explore in the future is to build an interferometer. The goal would be to split the beam using XRPBS, pass the split beam through a material for characterization, use the other beam as a reference, and then recombine the beams for detailed comparative analysis. The research team plans to use the MSTS end station facility at the Stanford Synchrotron Radiation Lightsource (SSRL) for this additional research.

Other NNSS projects that have been recognized in past R&D 100 awards are “The Aerial Reconnoiter Using Unmanned Systems (ICARUS)” in 2020 (finalist), “Falcon Plasma Focus” in 2019 (finalist), “Silicon Strip Cosmic Muon Detector” in 2018 (winner), “Geometrically Enhanced Photocathodes” in 2017 (winner), “Argus Fisheye Probe” in 2015 (finalist), “Nuclear Energy in Space” (the KiloPower project with LANL) in 2013 (winner), “Multiplexed Photonic Doppler Velocimeter (PDV)” in 2012 (winner), “Faster than the Speed of Sound” (the Movies of eXtreme Imaging Experiments (MOXIE) project with LANL) in 2010 (winner), and “In Shocking Conditions, Holograms Come Through” (the High-Resolution UV Holography Lens project) in 2009 (winner).

Of all these innovative projects, six began as SDRDs, making SDRD the largest contributor to R&D 100 success for the NNSS.

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Fighting climate change with UASs

cartoon image of UAS in front of plant

As part of the effort to fight climate change, the current federal administration has recently issued the U.S. Methane Emissions Reduction Action Plan (Executive Order 13990), which will require landfills, mines, and oil and gas well sites and their transport pipelines to reduce methane gas emissions by up to 75% by the year 2030. In order to meet this requirement, sources of methane leakage will need to be identified, measured, and repaired. Current models to accomplish this are done remotely with “top down” detection from aircraft and satellites, which can be costly and limiting for monitoring, reporting, and verification (MRV).

In an effort to reduce cost and increase ease of measurement and identification, Principal Investigator Hilary Tarvin and her indispensable team–Electrical Engineer Eric Schmidthuber, Technologist Sean Sheehan, and Mentor Michael Howard–conducted a feasibility study using the emerging technology of micro-electrical mechanical systems, or MEMs, and pairing them with small unmanned aircraft systems (sUASs). The study developed two prototype ground-based sensors and designed a UAS-deployable sensor package that incorporated commercial-off-the-shelf (COTS) methane sensors from Nevada Nano. These sensors were advantageous to this project because of their light weight (8 grams), low energy consumption (29 mW), and detection range (initial sensor range was 300–1,500 ppm with 1 ppm resolution and newly released sensor range increased to 50–1,000,000 ppm with 1 ppm resolution). These COTS sensors were also resistant to poisoning, featured built-in environmental compensation, and did not require calibration.

Ground-based sensor prototype installed on RSL-Nellis fence
Ground-based sensor prototype installed on RSL-Nellis fence.

The two ground-based sensors were installed and deployed along the fence line at the Remote Sensing Laboratory-Nellis and at the Methane Emissions Technology Evaluation Center at Colorado State University. Data were collected from both sensors that showed positive methane gas detections from leaks in the local environment, and thus proved the feasibility of using the sensors for such a purpose, but more work is required to develop data processing algorithms that account for local meteorological conditions in order to provide higher fidelity geolocation of the sources of methane releases.

The sensor deployed with the UAS also proved to be feasible in terms of structure and stability. The team was able to create a sensor package featuring the aforementioned sensors inside a 3/4″ PVC tube with a 3D-printed mounting head for the sensor unit. Using a small quadcopter provided by another SDRD team, the package was mounted onto the UAS and test lifts were achieved and successful. The package did not overburden the UAS with weight and there were no issues with maintaining stability.

UAS lifting the sensor package during stability testing
UAS lifting the sensor package during stability testing.

The overall conclusions of this study suggest that MEMs are feasible in the MRV of methane gases. Methane is a serious concern and this technology could prove instrumental in the fight against climate change.

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