Industry engagement is vital to the success of the FSP program, and there have been many excellent questions put forth. Idaho National Laboratory has assembled responses to many of the commonly asked questions that have been put forth thus far into an ‘FSP FAQ” and grouped the responses by category.

Note that any specific design requirements discussed herein will be formally defined in the RFP. This list was updated as of 12/22/2020, responses to additional questions will be added to this list. To submit a question, please email Brad Gravatt (



 Presentation material specifically stated, “moderated HALEU Reactor”. Is a moderator required and is there a preference for the fuel type/form? Similarly, will Pu be considered?  

FSP reactor fuel is limited to uranium fuel, low enriched (< 19.75% 235U) is preferred. This will be stated in the RFP. There is no additional requirement on the fuel form or type. A moderator is not required.


Would it possible to remove the Engineering Demonstration Unit (EDU) requirement to reduce cost and schedule? 

FSP represents a first-of-kind reactor that will require operation without readily available human intervention, a ground test demonstrating the full capability of design will be required prior to the flight system deployment. As such, this ground-based demonstration system will be called a Qualification unit (QU) as opposed to an EDU. An estimate of the technical, schedule and cost requirements to design, build and test a QU will be a Phase 1 requirement. The specific testing requirements will not be identified as part of Phase 1.


The RFI discussed a power-uprate capability for the design – how much is envisioned? 

Phase 1 specifies a minimum power output with a scalability assessment to 40kWe and above. For phase 1, uprate capability is not a requirement.


What is the deployment vision for the system? 


A mass and volume requirement for the system will be provided in the Phase 1 RFP. The system is required to operate on the lander and NASA does not envision providing additional technology developments or system hardware that will support regolith shielding on the lunar surface.

What is the driving need for a 1km cable? 


This requirement has been refined. The system is required to deliver a quick-connect interface to enable access to 120V-DC power at an interface point sufficiently distanced from the reactor such that radiation levels are 5 rem/year above background.

Will astronauts be present prior to landing the FSP? 


This has yet to be determined, but the FSP shall not assume astronaut involvement for maintenance or startup.

Are there requirements related to post-operation? 


Post operation requirements are not included at this time.


What GFE (Government Furnished Equipment) will be available for FSP? 


Phase 1 is a design effort, and no GFE is expected to be provided. Applicants can identify GFE that they require as part of their response to a Phase 2 estimate, including fuel, infrastructure (testing facilities), shipping services, etc.

How will industry get access to NASA/DOE research and technology development that is currently in progress?


NASA/DOE research is published and widely available. Any specific research that is unpublished but required for the purposes of the RFP will be made available to all parties responding to the RFP.

What will be the approval path for testing QU?


The Department of Energy nuclear safety requirements and regulations will apply should the QU be tested at DOE facilities.

Does NASA envision leveraging other concurrent technology development as part of FSP?


Proposers are encouraged to leverage whichever technologies judged to best enable mission success, there are no requirements or expectations that the industry must leverage a specific technology.

Can FFDRC’s be included as part of the proposal team?


No, FFRDC’s are not permitted to participate as part of a responding team. However, a responding team is permitted to leverage FFDRCs during contract execution, and if so the full cost of using FFDRC capabilities should be accounted for as part of the Phase 2 cost estimate.

Can subsystem providers be included in multiple team responses?


Yes, each responder may decide the composition of their integrated team.

What is the planned form of the Phase 1 contract?


The Phase 1 contract will be Firm Fixed Price.

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