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DOD Advances X-Energy Mobile Nuclear Microreactor as Second Project Pele Design
The Department of Defense (DOD) has moved to develop a second transportable microreactor under Project Pele, granting X-energy a contract option to advance the design of its mobile advanced nuclear microreactor prototype.
The one-year contract option will continue to provide funding for X-energy’s nuclear technology development, allowing the firm to develop its design to meet the DOD’s Project Pele technical requirements, the federal agency said on Sept. 13. On Sept. 15, X-energy confirmed it signed an agreement with the DOD under a federal initiative, but it noted that the agreement expands an existing contract with the agency to advance its prototype through a $17.49 million award.
Project Pele stems from the 2019 National Defense Authorization Act, in which Congress directed the DOD and the Department of Energy (DOE) to develop a plan to design, build, and test a microreactor at a DOD installation no later than December 2027. When the DOD’s Strategic Capabilities Office (SCO) formally released a record of decision (ROD) to proceed with the program in April 2022, it said it would pursue a high-temperature gas-cooled (HTGR) mobile microreactor that will be capable of producing 1 MWe to 5 MWe for more than three years without refueling. The SCO considered two engineering designs selected as part of a preliminary design competition, which wrapped up in March 2021: an HTGR design from BWXT Advanced Technologies and X-energy’s Mobile Nuclear Power Plant.
Microreactors—small nuclear reactors that produce up to 20 MW of electricity or equivalent amounts of heat—are designed for small applications away from the centralized electric grid such as remote communities and military bases. Source: INL
The DOD in June 2022 ultimately picked BWXT’s microreactor, a selection that implied the much-watched contest to build what could be the nation’s first advanced microreactor was closed. On Wednesday, however, the SCO said the contract option extended to X-energy could provide future optionality. “Due to their extraordinary energy density, nuclear reactors have the potential to serve multiple critical functions for meeting resiliency needs in contested logistical environments,” said Dr. Jeff Waksman, Project Pele program manager. “By developing two unique designs, we will provide the Services with a broad range of options as they consider potential uses of nuclear power for both Installation and Operational energy applications in the near future.”
The SCO, however, clarified that the contract option “will not result in a completed engineering design,” though it will allow a “thorough analysis of design options, leading to a Preliminary Engineering Design and initiation of a regulatory pre-application process.”
X-Energy Expects to Advance Its Prototype Design
According to Project Pele’s final environmental impact statement, which the DOD made public in February 2022 prior to its ROD, X-energy proposed a “Mobile Nuclear Power Plant” concept that will employ a TRISO-fueled reactor coupled to a high-reliability power conversion system—“each contained in separate ISO-compliant containers to achieve maximum siting flexibility, limit hardware activation, and improve maintainability.”
X-energy in 2020 revealed it was working on a 7-MWe “Xe-Mobile power generation system,” which will use X-energy’s proprietary TRISO-X fuel. However, the company has not publicly disclosed its Project Pele concept.
An X-energy spokesperson on Thursday told POWER that the company is currently focusing its mobile microreactor work “around one practical, cost-effective microreactor that can be deployed for use in remote military locations as well as commercial or industrial use.” X-energy’s transportable microreactor “is designed to generate in the range of 3 to 5 MW and is differentiated to be cost-competitive with remote diesel power. The microreactor is designed to use TRISO-based fuel,” he said.
On Friday, Harlan Bowers, X-energy president, who led a project team during the initial phase of Project Pele work, said the company will draw from the “tremendous” experience it gained from DOD subject matter experts during the first phase.
“We intend to build on the knowledge and experience from the first phase of work to create a clean, practical, and cost-effective microreactor to be competitive with fossil fuel-based power generation used today,” he said. “We expect this next phase of work to include the refining of our design, prototype testing, and initiation of reviews with the U.S Nuclear Regulatory Commission [NRC] to ensure our microreactor meets safety standards and can be licensed for civilian use in the U.S.” Pre-licensing engagement with the NRC will “enable a broad range of deployment possibilities to decarbonize off-grid, remote, or small-scale grid resiliency needs,” the company added.
The technology firm’s more prominently known offering is its larger 80-MWe (200-MWth) Xe-100 design. The company is notably slated to demonstrate a proposed four-unit 320-MWe Xe-100 advanced nuclear reactor facility at a Dow chemical materials manufacturing site in Seadrift, Calhoun County, Texas, as part of the DOE’s Advanced Reactor Demonstration Program (ARDP).
Dow and X-energy are preparing a construction permit application for submittal to the NRC, and plant construction could begin in 2026. The firm in October 2022, meanwhile, kicked off construction of its TRISO-X Fuel Fabrication Facility (TF3) in Oak Ridge, Tennessee, targeting a commercial operational date in 2025.
DOD’s Second Major Microreactor Announcement In a Month
The SCO’s announcement comes on the heels of the U.S. Air Force’s selection of Oklo’s Aurora Powerhouse—a liquid metal-cooled fast reactor—for a nuclear microreactor pilot at Eielson Air Force Base in Alaska. The Air Force’s Micro-Reactor Pilot Program, which also responds to a 2019 National Defense Authorization Act requirement, seeks to build and operate at least one licensed microreactor by Dec. 31, 2027.
The Air Force, however, is exploring a different approach. Oklo will site, design, build, own, and commercially operate the stationary microreactor, while the Air Force will execute a land lease and the 30-year fixed price power purchase agreement with Oklo once the nuclear technology firm obtains a combined operating license from the NRC.
BWXT, meanwhile, has said its Project Pele transportable design “consists of multiple modules that contain the microreactor’s components in 20-foot long, ISO-compliant CONEX shipping containers.” In addition, the reactor is designed to be safely and rapidly moved by road, rail, sea, or air.
“The entire reactor system is designed to be assembled on-site and operational within 72 hours. Shut down, cool down, disconnection, and removal for transport is designed to occur in less than seven days,” it said. BWXT’s transportable reactor core and associated control system are pivotally designed to maintain safety “under all conditions, including transitional conditions throughout transport,” it added. These attributes meet the DOD’s specifications, it said.
Reactor fuel for the Project Pele demonstration is slated to be produced from DOE of highly enriched uranium (HEU) currently stored at the Y–12 National Security Complex in Oak Ridge, Tennessee, the DOD’s 2022 ROD noted. The fuel will be converted from a metal to an oxide at BWXT Technologies’ Nuclear Fuel Services facility in Erwin, Tennessee, and then downblended to high-assay low-enriched uranium (HALEU) and fabricated into tristructural isotropic (TRISO) reactor fuel at the BWXT facility in Lynchburg, Virginia.
BWXT Project Pele Project Readying for Delivery in 2025
During a webinar hosted by the American Nuclear Society (ANS) on Aug. 2, BWXT Advanced Technologies President Joseph Miller noted work is underway at its Lynchburg facility to ready the microreactor for a minimum three-year period of testing at Idaho National Laboratory (INL) in 2025.
Waksman, who heads up the SCO’s Project Pele, during the webinar said the BWXT DOD project is now in the “final bits of the design phase” in preparation for final approval by the DOE, which acts as the project’s “regulator.” SCO’s current schedule is to have the final design approved by the DOE by the spring.
After the DOE signs off, he said, SCO will assemble the reactors in Lynchburg over the course of 2024. “And if all goes according to schedule, by early 2025, we will have shipped the reactor to INL, where it will be fueled. It will then be shipped out to the desert, to a location we have selected to do the initial testing,” he said. “After we operate the reactor, we will then demonstrate this transportable reactor down, putting it on a truck, driving it around a bit, putting it back up again, and turning it back up again.”
The microreactor’s development is tailored to DOD purposes, largely focused on three applications: providing remote power; offsetting fossil fuels for strategic and operational advantages; and ensuring resilience. “Our reliance on long and vulnerable fossil fuel lines is a huge problem from a military perspective, so having power that does not require refueling for days or months or even years would be a huge advantage for us,” Waksman said.
Waksman, however, added that the DOD’s efforts could prove fruitful for larger industrialization. “Our plan from the start has always been that we want to build reactors that can have commercial spin-offs so that we can get the number of reactors coming off the assembly line to be enough that it will be cost-competitive,” he said.
注释：
microreactor: n
表示"微型反应器"，如：Experimental results show that microreactor has significant advantages respecting the study of catalytic pyrolysis compared to other reactors. 试验结果表明，对于催化裂解过程的研究，微型反应器有其它形式反应器所不具备的独特优势。
prototype: n
表示" 原型；雏形"，means " first or original example of sth that has been or will be copied or developed"，如：Designers have built a working prototype of the car. 设计者已经制造了汽车的工作原型。
resiliency: n
表示" 跳回(回弹；弹力；弹性变形；冲击值)"，means "an occurrence of rebounding or springing back"，如：VITUBE possesses the high resiliency of an elastomer as well as the good mechanical properties of conventional synthetic rubbers. 软管不仅占有弹性体的回弹力，还具有常规合成橡胶的机械属性。
decarbonize: v
表示" 除去碳素"，means "remove carbon from (an engine)"，如：Even so, as China charges forward, global corporations have come calling with hopes of cashing in on the quest to "decarbonize" energy. 即使这样，由于中国实行运费到付，全球的公司已经从“脱碳”能源中看到了商机。
convert: v
表示"转化；兑换；换算"，means "make to change from one (form, use, etc.) into another"，如：The solar cell can convert the energy of sunlight into electric energy. 太阳能电池能把阳光的能量转化为电能。
tristructural: adj
表示"三相结构的"
isotropic：adj
表示" 各向同性的；等方性的"，如：On large spatial scales, the Universe is homogeneous and isotropic. 在大尺度的观测下，宇宙是均质与各向同性的。
spin-off：n
表示"副产品"，means "a product made during the manufacture of something else"，如：This new material is a spin-off from the space industry. 这种新材料是航天工业的副产品。
中文简要说明：
美国国防部 (DOD)再次加注资金，以推动微型核反应堆(microreactor)的研发工作。新创企业X-energy公司获得一份为期一年的合约，以完善微反应炉的设计。该公司成为第2个受到国防部肯定的微型核能设计公司。
电力杂志(Power mag) 报导，2019年，美国国防授权法案中，有一项国防部(DOD)和能源部 (DOE)共同制定的小型机动式核电设备计划，称为「贝利项目」(Project Pele)，求一种能够产生 1~5百万瓦时(MWe)电力的高温气冷型 (HTGR) 机动微反应炉，并且至少3年不需再添燃料。该竞赛于 2021 年 3 月结束，最终由核燃料供货商BWXT先进科技公司(BWXT Advanced Technologies)的设计获胜。
不过，9月13日，美国联邦政府再开一个短期合约，给X-energy公司1749 万美元的核技术开发资金，等于是第2张合约微型反应炉的制作合约。
贝利项目的官员-瓦克斯曼博士(Jeff Waksman,)说，扩增X-energy的合约，是在未来提供另一种微反应炉的选择权。「核反应堆有着极佳的能量密度，是一种极具潜力的关键能源。开发两种独特的设计，在未来将有更广泛的选择。」
贝利项目原本的胜者，BWXT先进科技公司使用的是较传统的「高含量低浓缩铀」(HALEU fuel)，也就是比现有核电厂的3~5%铀235浓度燃料，提高到5~20%的区间，在理论上，它的使用效率会比现行的反应炉来的好，而较小的反应炉尺寸，具有自然对流冷却的效果，不需要人员额外控制。
而X-energy的设计则采用较独特的高硬度铀碳氧燃料(TRISO fuel )，每粒燃料为小圆珠型，安装在符合ISO 标准的反应炉中，这种石球式反应炉可以设计的更具灵活性、高压气体冷却的安全性也足够，绝对没有福岛事故的锆水反应。X-energy 在 2020 年透露，他们正在开发7百万瓦时的X-Mobile 机动式核能发电系统，该系统将使用 X-energy 专有的 TRISO-X燃料。
此计划与贝利项目无关，而且已获得其他民间公司合作，显然这是国防部突然授与他们合约的原因。
X-energy正在推动的是Xe-100 反应炉设计，此为美国能源部先进反应炉示范计划 (ARDP) 的一部分，该公司与陶氏化学(Dow)达成业界联盟，计划在德州西得里夫特( Seadrift) 的陶氏材料基地，建造4座320百万瓦时的Xe-100 先进核反应堆。
目前，陶氏化学和 X-energy 已向美国核管局提出施工许可申请，可能于 2026 年开始建造。与此同时，该公司已在2022 年 10 月，于橡树岭国家实验室(ORNL)，建造 TRISO-X 燃料的制造厂，期望在2025 年进入商业投产。
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