NNSA Deputy Administrator speaking at the CTBTO Science and Technology 2023 conference. She is on a large stage with a video screen behind her and giant letters SnT23 nearby
NNSA Deputy Administrator Corey Hinderstein speaks at the CTBT: Science and Technology 2023 conference.

Thank you for that kind introduction. I’m pleased to be here in Vienna at SnT23 to talk about US actions that support our commitment to the nonproliferation and disarmament goals of the NPT and the CTBT. Yesterday, NNSA Administrator Hruby spoke about the importance of the CTBT to the United States and described some specific areas where NNSA is supporting the CTBTO PrepCom and the U.S. nuclear explosive testing moratorium. My hope is that you will learn even more about our support for international nuclear explosion monitoring and verification from the many U.S. talks, posters, and displays this week. Today, I’ll expand on the Administrator’s remarks to discuss more examples of U.S. transparency and verification. As a responsible nuclear power, we work hard to be transparent about our activities in the U.S. nuclear security enterprise, from nonproliferation research and development all the way to dismantlement and disposition of nuclear weapons and materials.

One key point to understand is the significant reduction in the U.S. nuclear weapons stockpile of 88 percent from its peak and the importance of a strong international commitment against nuclear explosive testing. We do not need, and do not plan, to conduct nuclear explosive tests. The United States continues to observe its nuclear explosive testing moratorium as part of our commitment to the letter and the spirit of the CTBT, and calls on all states possessing nuclear weapons to declare or maintain a moratorium on nuclear explosive testing.

Examples of Verification

I’d like to start with a number of examples of how the United States supports the important work of the CTBTO Preparatory Commission and the Provisional Technical Secretariat.

  • The United States is the largest contributor among signatory states, and we also fund the operation, maintenance, and recapitalization of 36 U.S. International Monitoring System (IMS) stations. In addition, the U.S. Government, through NNSA and the Departments of State and Defense, funds U.S. experts to assist the PTS and advance the state of the art in nuclear explosion monitoring and verification. All told, this amounts to well over 50 million dollars annually that directly benefits the international effort.
  • We are proud of several additional projects that are enhancing the PTS mission, such as Xenon International, which was recently accepted for use by the IMS. Xenon International significantly improves radioxenon collection and analysis systems deployed in the IMS, collecting larger air samples and reducing processing time. This allows it to detect lower levels of radioxenon more quickly, giving scientists more accurate clues about the potential source of a suspect nuclear explosion. We expect the first Xenon International unit to be fielded in the IMS next year.
  • Other U.S. activities address the challenge of distinguishing emissions from the production of life-saving nuclear pharmaceuticals from signals that could indicate a nuclear explosion. One of those is the Workshop on Signals of Man-Made Isotope Production, or WOSMIP. Even through the COVID pandemic, we hosted WOSMIP virtually to bring together scientists from two very different communities to discuss ways to maintain robust and effective nuclear explosion detection and monitoring networks. Our last workshop was in June 2022 in Stockholm, Sweden, and I hope many of you will consider joining us in Santiago, Chile, in December 2023.
  • A related project is the Source Term Analysis of Xenon, or STAX, where the United States provides fission-based medical isotope producers with state-of-the-art stack monitors to record radioxenon emissions. That can help distinguish harmless emissions from an unexpected spike that may result from a nuclear explosive test. We have so far installed stack monitors in six facilities, including two in the United States, and we have plans for many more.
  • I’d also like to commend Belgium’s National Institute of Radioelements. They not only installed a U.S.-supplied stack monitor in 2017 but they recently converted their medical isotope production facility to use low‑enriched uranium or LEU for their targets, instead of proliferation-sensitive highly enriched uranium. As a result, all major global molybdenum-99 production facilities now use LEU targets.
  • International Data Centre (IDC) Re-engineering is another major project with significant U.S. contributions. The IDC’s waveform data processing system benefits from continuous modernization, and the United States has so far provided the IDC with four major software updates. We owe a collective “thank you” to the Air Force Technical Applications Center (AFTAC), who have allowed upgrades to the U.S. National Data Center to be leveraged for the benefit of the IDC.
  • Sandia National Laboratories conducts IMS component evaluation at the Facility for Acceptance, Calibration, and Testing, or FACT Site, through a contract directly with the PTS. This is a unique capability in a remote and quiet location in New Mexico that allows traceable testing of very precise components and systems, resulting in deployment of more reliable and robust seismic and infrasound equipment in the IMS.
  • The PTS has another contract with Idaho National Laboratory to provide radioxenon “standards” or precise quantities of radioxenon gas to help to calibrate instruments and evaluate CTBT Radionuclide Laboratories during proficiency test exercises.
  • Pacific Northwest National Laboratory operates one of the radionuclide laboratories that accept particulate and gas samples of high interest from IMS stations for detailed analysis. RL-16 at PNNL has consistently received outstanding ratings from the PTS for its work.
  • In 2015, then-NNSA Administrator Frank Klotz spoke at SnT15 where he responded to the PTS request for help with more realistic on-site inspection training by allowing CTBT OSI training at the former Nevada Test Site, now the Nevada National Security Site or NNSS. As you can imagine, it was a huge undertaking to support CTBT OSI training at an NNSA site, but in May 2016, less than a year after our offer, we hosted 41 surrogate inspector trainees and PTS staff from 32 countries in Nevada. In October 2017, we hosted visual observation and radionuclide sampling training in Nevada for trainees and PTS staff from 39 countries.
  • The United States also played a large role in the success of the Integrated Field Exercise in 2014, and we are engaged and excited to provide support for IFE25.
  • In collaboration with the PTS, NNSA sponsors workshops to expand the use of the Regional Seismic Travel Time or RSTT model and help developing National Data Centers improve their ability to protect infrastructure against earthquakes, while preserving IDC capabilities. The last RSTT workshop was in Nepal in November 2022.
  • The NNSA Seismic Cooperation Program collaborates with the PTS to engage regional counterparts to build seismic monitoring capability, with a focus on the Caucasus, Central Asia, Middle East, and North Africa.
  • The United States supports three Working Group B Task Leaders and the Radionuclide Expert Group Chair. We believe in the key role that States Signatories play in the work of the PTS through bodies like Working Group B.
  • There are too many NNSA experts here to name them all, but I want to call out one of our very best. Many of you know Dr. Harry Miley, a Laboratory Fellow at Pacific Northwest National Laboratory. His work for over thirty-five years in nuclear explosion monitoring and verification has set the standard for excellence. He was a co-developer of one of the mainstay technologies in the IMS, the Radionuclide Aerosol Sampler/Analyzer, or RASA. He led the radionuclide portion of the Inspection Team at the 2014 Integrated Field Exercise in Jordan. Dr. Miley was a key figure in PNNL’s understanding of radioactive releases from Fukushima in 2011. He is stepping back from full‑time work soon after SnT23 but has promised us he’ll be around to consult. Harry, please stand and be recognized for your outstanding contributions.

I encourage you to seek out Dr. Miley and the team of NNSA experts here this week to learn more about these and other projects that support the CTBT.

Corey Hinderstein speaks to the CTBTO SnT23 audience.
Corey Hinderstein speaks to the CTBTO SnT23 audience.
Examples of Transparency

I’ll now turn to some examples of U.S. transparency related to activities at our nuclear security enterprise sites such as the Nevada National Security Site and the national laboratories. As a responsible nuclear state, we see it as our obligation to be transparent about our activities within the nuclear security enterprise, including underground. These activities also can counter suspicion and uncertainty about our activities, and misinformation or misunderstandings about what we do and why we do it.

  • We have hosted Dr. Floyd and his predecessors at many DOE sites to see our activities. Most recently, I was proud to host Dr. Floyd along with senior U.S. interagency representatives at Los Alamos and Sandia National Laboratories as well as the Nevada National Security Site. We took Dr. Floyd almost 1000 feet underground in Nevada to see the subcritical experiment “zero room” and also some enhancements we are making at the U1a Complex to allow us to continue to maintain the U.S nuclear stockpile without nuclear explosive testing. I will speak more about subcritical experiments in a moment.
  • In October 2016, we were pleased to host Dr. Zerbo and a distinguished group of international diplomats in Nevada. Along with UNVIE and Dr. Floyd, we are well underway with planning for a similar visit to Nevada and New Mexico in November of this year.
  • We also host international disarmament and nonproliferation officials at NNSA sites to highlight how the U.S. Government is actively supporting the Treaty on the Non-Proliferation of Nuclear Weapons, or NPT. In July 2022, prior to the Tenth NPT Review Conference, we welcomed 10 observers from around the world to Sandia and Los Alamos National Laboratories to demonstrate our commitment to global nonproliferation and a safe and secure nuclear stockpile without nuclear explosive testing.
  • We are also transparent about our nuclear policy and policy objectives. Every year, the NNSA publishes a Stockpile Stewardship and Management Plan and releases it to the public. The most recent plan, published in April, describes in great detail NNSA’s efforts to implement the United States’ 2022 Nuclear Posture Review by maintaining a safe, secure, reliable, and effective nuclear weapons stockpile without nuclear explosive testing as well as revitalizing the nuclear security enterprise’s infrastructure and scientific capabilities. To quote the NPR, “The United States supports the CTBT and is committed to working to achieve its entry into force, recognizing the significant challenges that lie ahead in reaching this goal.” These documents, along with highly detailed budget justifications and public remarks, give the public and the international community significant transparency into our activities.
  • Another component of the Stockpile Stewardship Program is subcritical experimentation. As you may have heard Administrator Hruby mention yesterday, we are exploring multiple opportunities to provide further transparency into our subcritical experiments program. These experiments, permitted by the CTBT, help us to maintain the U.S. stockpile without nuclear explosive testing.
  • These experiments are specifically designed so that no self‑sustaining nuclear fission chain reaction can occur, making them consistent with the CTBT.
  • The Nevada National Security Site is the primary U.S. location where experiments with radioactive and other high-hazard materials are conducted, and the only location where high-explosive driven plutonium experiments can be conducted.
  • We have executed 33 subcritical experiments since 1992, when we performed the last U.S. nuclear explosive test, and we have plans for two subcritical experiments in fiscal year 2024, which is from October 2023 to September 2024. We are open with the public and the international community about our plans for subcritical experiments.
  • NNSA also supports two Defense Nuclear Nonproliferation programs which use data from field experiments conducted at the Nevada National Security Site test beds to validate nuclear explosion monitoring models, algorithms, and sensors. A multi‑year field experiment at one of the NNSS tunnels is underway, consisting of subsurface chemical explosions and other surrogates to understand how low-yield nuclear explosive test signatures are propagated. And second, a multi-year field experiment to directly compare shallow depth earthquake and explosion signatures, which is just starting construction activities at NNSS.
  • For large non-nuclear explosions at the NNSS, NNSA practices transparency by notifying the PTS in advance of high explosive experiments so they can be sure the relevant IMS stations are operating to detect seismic signals. This was most recently done in September 2020 for a series of explosive tests designed to validate the main high-explosive charge for future experiments. The next high-explosive experiment is planned to take place in late 2023. In addition, NNSA makes data sets and scientific publications available to the public after conducting these experiments. Here, the most recent example is the 2021 report releasing the data for experiments that took place in 2018 through 2019 in Nevada.
  • I also want to take what may be an uncomfortable subject head-on. While we have no intention of returning to nuclear explosive testing, it would be remiss of me to give this talk and not acknowledge that we do have Presidential direction to maintain the readiness to conduct a nuclear explosive test. To be clear, test readiness requirements have existed across multiple Administrations and doesn’t change the fact that the United States has no plans to conduct a nuclear explosive test.
  • Let me end my remarks on transparency with this. In December 2022, a team at Lawrence Livermore National Laboratory’s National Ignition Facility conducted the first controlled fusion experiment in history to reach the milestone of fusion ignition, which produced more energy from fusion than the laser energy used to drive it.

We do not need, and do not plan, to conduct nuclear explosive tests. The United States continues to observe its nuclear explosive testing moratorium as part of our commitment to the letter and the spirit of the CTBT, and calls on all states possessing nuclear weapons to declare or maintain a moratorium on nuclear explosive testing.

Corey Hinderstein
NNSA Deputy Administrator for Defense Nuclear Nonproliferation
  • This experimental result at the National Ignition Facility opens the door to an unprecedented capability to gain new understanding for our Stockpile Stewardship but also provides insights into prospects for clean fusion energy. Achievement of ignition will lead to laboratory experiments that help NNSA maintain confidence in our deterrent without nuclear explosive tests.
  • In the words of Secretary of Energy Granholm, “This is a landmark achievement for the researchers and staff at the National Ignition Facility who have dedicated their careers to seeing fusion ignition become a reality, and this milestone will undoubtedly spark even more discovery. The Biden-Harris Administration is committed to supporting our world-class scientists—like the team at NIF—whose work will help us solve humanity’s most complex and pressing problems, like providing clean power to combat climate change and maintaining a nuclear deterrent without nuclear testing.”

On a personal note, before I finish I’d like to recognize Dr. Floyd and the CTBTO Preparatory Commission’s efforts on diversity and inclusion. As part of his commitment, I know that Dr. Floyd became an International Gender Champion in 2021 and he looks for opportunities to attract people from all over the world with a view to ensuring the highest standards of professional expertise, experience, efficiency, competency, and integrity. At NNSA, I lead our office’s Diversity, Equity, Inclusion, and Accessibility Initiative within Defense Nuclear Nonproliferation where we aim to recruit, develop, and retain the very best talent, recognizing that some groups have been historically underrepresented in the nonproliferation, disarmament, and arms control field. Many of the NNSA participants in the SnT23 are female, including the NNSA Administrator and yours truly, and we encouraged many early and mid-career experts to attend and present this week.

In closing, I hope I have been able to demonstrate the deep commitment of the United States to the nonproliferation and disarmament goals of the NPT and the CTBT, going beyond the core tenants of the CTBT by not only maintaining the U.S. stockpile as long as it exists without nuclear explosive testing, but by being transparent about our ongoing and planned activities and providing strong support to the PTS. We provide unprecedented insight into our work and welcome the international community to see how we do business. We hope other responsible nuclear powers will follow our lead.

With that, I thank Dr. Floyd and the SnT23 organizers for the opportunity to be with you today. Thank you.