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Joint Meeting ANS-DC Section and BWCHPS

April 14, 2021 @ 7:00 pm - 8:30 pm EDT

The ANS-DC Section and the BWCHPS host a joint meeting on power reactors and related environmental assessments.

Guest Speakers:

Travis Chapman, Licensing Engineer, X-Energy, and

J. Stewart Bland, CHP, Principal Health Physicist, SC&A and Chesapeake Nuclear Services, Inc.


Travis Chapman, U.S. Licensing, X-Energy

Deploying Advanced Reactor Technologies with X-Energy


X-energy is developing advanced reactor solutions for a variety of clients and use-cases, from the modular Xe-100, a 200MWth pebble-bed high temperature gas reactor, the Xe-Mobile, a TRISO-fueled microreactor, and a growing business line with its unique TRISO-X coated-particle fuel. Come learn how X-energy’s roots in the space industry have grown into an advanced reactor developer bringing Generation IV reactor designs to commercial readiness in the 2020’s. The X-energy team will discuss the state of their Xe-100 reactor technology and TRISO-X fuel, how they are addressing U.S. licensing challenges like mechanistic source term analysis, and the prospective U.S. and international market for high temperature energy products.

X Energy, LLC (X-energy) is a nuclear reactor & fuel design engineering company that develops Generation IV high temperature gas cooled nuclear reactors & the TRISO-X fuel to power them. The flagship Xe-100 is a 200MWth pebble-bed reactor that is simple, modular, and intrinsically safe. The company is also pursuing reactor solutions for space power and propulsion, microreactors for defense, disaster relief, and remote communities, and manufactures its own TRISO coated particle fuel. You can learn more at http://www.x-energy.com.


Travis Chapman brings 18+ years of technical expertise in reactor operations, commercial and defense nuclear safety, and licensing to the X-energy team and leads the U.S. licensing efforts for the Xe-100 reactor. He was most recently Associate Chair of the Mechanical Engineering Department at the U.S. Naval Academy and has had progressive leadership opportunities as a submarine officer and S8G reactor supervisor, civilian Federal service at the Nuclear Regulatory Commission and Defense Nuclear Facilities Safety Board, and was employee #3 at Oklo, Inc., a reactor design start-up supporting regulatory affairs and conceptual system design. Travis received a BS in Naval Architecture from the U.S. Naval Academy and Masters degrees from Old Dominion University (Engineering Management) and University of Maryland (Nuclear Engineering), and is a Commander in the U.S. Navy Reserves.

J. Stewart Bland, CHP:

Updates in Radiological Assessments Methods for New Build and Operating Nuclear Plants


The methods prescribed by NRC for radiological assessments required for nuclear plant licensing and operational evaluations were formulated in the 1970’s; the models and methods have remained mostly the same ever since. The development of these models was initiated by the Atomic Energy Commission primarily at its Hanford operations to support detailed pathway dose assessments as needed for implementing the ALARA concept for radioactive effluents first proposed in 1970. The continued application of the final models, as included in Regulatory Guide 1.109, Rev. 1, has provided stability and consistency in the licensing process – but at the cost of generally being considered overly conservative and out-of-date with current radiation dosimetry and environmental kinetics. A key justification for not updating is that the models and methods overall remain conservative (and generally applicable).

This presentation will discuss the recent upgrades to the NRC’s licensing computer codes LADTAP (liquid effluents pathway), GASPAR (gaseous effluents pathway) and XOQDOQ (meteorological modeling). Enhanced user interface features now allow for easier integration of site-specific parameters into the generic model. Options for use of ICRP-30 or ICRP-60/72 dose conversion factors have been incorporated. Upgraded biota dose modeling has been incorporated for the gaseous pathways, as needed to support NEPA analysis.


J. Stewart Bland is a Health Physicist, Certified by the American Board of Health Physics, a Fellow of the Health Physics Society, and a member of the American Nuclear Society. He has over 40 years of regulatory and operational experience in health physics and radiation safety, including seven years with the NRC in both licensing and inspection and enforcement. For the past thirty plus years, Stewart has provided health physics and radiological safety consulting to industry, government and private entities with emphasis on environmental pathway modeling and dose assessment. He has directed decommissioning planning and application of MARSSIM for characterization, license termination and final status surveys. Stewart is the recipient of the 2019 Jason Jang Award presented by the Radiological Effluents and Environmental Workshop (REEW) organized by the Nuclear Energy Institute (NEI) under the auspices of Organisation for Economic Co-operation and Development (OECD) and International Atomic Energy Agency (IAEA). Stewart earned his BS in Physics and MS in Nuclear Science from the Georgia Institute of Technology.

Cost Free

Registration required.

Hosted by:

The Baltimore-Washington Chapter of the Health Physics Society and DC-Section of the American Nuclear Society


April 14, 2021
7:00 pm - 8:30 pm EDT
Event Category:


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