Talk:Aircraft Nuclear Propulsion

Which HTRE is which?
You are correct that the plaque states that the HTR1 is on the left when viewed from the parking lot. Unfortunately, this does not refer to the paved parking lot that you took the picture from, but from the old gravel parking lot on the other side. More importantly, the HTR3 has its J-47 engines in a "horizontal flight configuration" as opposed to being vertical on the HTR1. These horizontal engines can be seen parallel to the top of the chain link fence on the left most portion of the picture. The vertically mounted engines on the HTR1 are obscured by the frame, but they are the right most portion on the reactor to the right. [I'm new to editing Wikipedia pages, so I didn't know where to document why I made the change. I also don't have a sign-in.] 72.198.222.129 (talk) 17:36, 3 June 2010 (UTC)
 * When I reverted this this morning I looked around for references to show which one is which...haven't found anything yet. The INL site hasn't given up a useful designation of which unit is where. --Wtshymanski (talk) 22:10, 3 June 2010 (UTC)
 * This ] shows HTRE 1 with the snail-shaped object on the left and large horizontal cylinder, and HTRE 3 with the ladder on the right and vertical cylinder. I don't have a usable photo of the plaque. I will restore the previous change. Scores of Wiki echo sites have repeated my error. --Wtshymanski (talk) 22:23, 3 June 2010 (UTC)
 * As I mention below, aviation-history.com before June 2019 had incorrect captions. They've since been updated based on documentation from INL. -Waded (talk) 17:28, 26 November 2019 (UTC)
 * I'm now confused - which was also known as HTRE 2 with a different core? Did HTRE 2 become HTRE 3 or was HTRE 2 the same hardware as HTRE 1 with a different core? --Wtshymanski (talk) 22:23, 3 June 2010 (UTC)

The J-47 engines were horizontal on both assemblies. They had to link up with fixzed ducting that led to an exhaust stack. It is the reactor vessels that are vertical (HTRE 1&2) and horizontal (HTRE-3). The picture inthe wikipedia article is correct in identifying which is which. The J-47 engines on the HTRE-3 assembly were removed and disposed of due to radioactive contamination. At the end of the program, General Electric published a series of technical reports documenting the history of the ANP. These are numbered APEX 901 and higher. Perhaps the INL technical library can help you locate these reports.--TomMacsub (talk) 06:38, 28 October 2010 (UTC)
 * This is correct. HTRE-2 has the vertical reactor vessel/cylinder and horizontal J-47 turbojets, the turbojets still present on the display as of 2019. HTRE-3 has the horizontal vessel/cylinder, but its horizontal J-47 turbojets were removed prior to 1989, leaving just ducts pointing downward where the turbojets used to attach. This is supported by a 60 page document, EGG-2575, titled "Final Report: Decontamination and Decommissioning of Heat Transfer Reactor Experiment Test Assemblies HTRE-2 and HTRE-3", produced for Idaho National Laboratory (INL), by Thomas K. McCusker, dated September 1989. The document goes into detail on activities related to cleaning and moving both reactors to the site. It includes photos of HTRE-3 before and after the turbojets were removed, photos of HTRE-2, photos of both assemblies being moved to current location, on current location, and many other detail illustrations clearly distinguishing HTRE-2 from HTRE-3 piece by piece for purposes of contamination level record. The document's currently available at https://inldigitallibrary.inl.gov/PRR/81118.pdf and I've cited it to correct the article/captioning. It's also available here: https://ar.icp.doe.gov/owa/getimage_2?F_PAGE=1&F_DOC=EGG-2575&F_REV=00


 * As additional evidence, an interpretive display in the hut between the two assemblies has illustrations overlaid on photos showing the difference in reactor and turbojet orientation of HTRE-2 vs. HTRE-3, identifying them as the INL document cited does. Someone took a picture of this display: https://www.flickr.com/photos/rocbolt/10367651026/in/album-72157636730882993/. (Unfortunately a lot of the other photos in that Flickr album are incorrectly captioned, as the assemblies, as of 2013, have signs on the surrounding fences that contradict themselves and this particular display.)


 * As for HTRE-1, according to the INL decommissioning/decontamination document, HTRE-2 "was a modification of the HTRE-1 core that allowed removal of a center fuel assembly." The interpretive display mentioned above states the HTRE-2 test assembly was created to "house the HTRE-1 core." So it is correct to say the HTRE-2 assembly is also HTRE-1, at least in parts. But I think to avoid controversy this article should call it HTRE-2, as the INL document does.


 * In June 2019 I contacted the owner of oft-cited aviation-history.com article on nuclear powered aviation by Raul Colon, which had incorrect captions on its photos. The owner agreed to look into this. As of December 2019 the owner's update the article/captions based on the INL document cited here. The aviation-history.com article (now corrected), and the (hopefully now corrected) contradictory signage at the site seem to have been primary sources of misinformation about which HTRE is which. -Waded (talk) 17:41, 26 November 2019 (UTC)

Thorium
were these planes powered by a Liquid fluoride thorium reactor (LFTR)? http://energyfromthorium.com/2006/04/22/a-brief-history-of-the-liquid-fluoride-reactor/ http://home.engineering.iastate.edu/~pjscott/Sorensen_Google_LFTR.pdf thanks James Michael DuPont (talk) 14:06, 14 October 2011 (UTC)
 * No. Strictly speaking, none of the planes were ever powered by any reactor at all; the reactor flown on the NB-36H was a conventional one. - The Bushranger One ping only 16:40, 14 October 2011 (UTC)