Preserving World War II-era Atomic Weapons Research and Development Sites

On This Page Navigation

This is a transcript of a presentation at the Preserving U.S. Military Heritage: World War II to the Cold War, June 4-6, 2019, held in Fredericksburg, TX. Watch a non-audio described version of the presentation on YouTube.

Preserving World War II-era Atomic Weapons Research and Development Sites within Los Alamos National Laboratory for the Newly-created Manhattan project National Historical Park

Presenters: Jeremy C. Brunette and J.T. Stark


Preserving Manhattan Project-era research and development sites within the confines of Los Alamos National Laboratory for public visitation presents a variety of significant challenges involving the interpretation and preservation of historic structures and landscapes within an active and highly secure national security area. Preservation planning involving the Los Alamos National Laboratory and the National Park Service can be difficult to coordinate. However, our early success on the preservation front demonstrates that these types of partnerships can succeed.

Federal legislation was signed creating the Manhattan Project National Historical Park in December 2014. Manhattan Project N.H.P. contains three separate units spread across the country that were instrumental in the development of the world’s first atomic weapon. The other units are Hanford in Washington state and Oak Ridge in Tennessee. Los Alamos properties include historic buildings in downtown Los Alamos and 17 Los Alamos National Laboratory structures located in eight technical areas. The Manhattan Project N.H.P. represents an atypical National Park Service (NPS) unit in that the Department of Energy, not the Department of the Interior, holds ownership of the property while the NPS is responsible for interpretation and supplying preservation expertise.

The Preservation Program at nearby Bandelier National Monument collaborated with the Los Alamos National Laboratory’s Historic Buildings Program to address preservation concerns at Pajarito Laboratory (TA-18), which is identified as the first area to feasibly allow for public access. TA-18 has a long history of human activity ranging from pre-contact and European settlements to intense utilization during the Manhattan Project and through the Cold War. The few remaining structures at TA-18 were retained because significant activities performed within them supported Manhattan Project and Cold War nuclear weapons research. This paper will focus on two Manhattan Project-era buildings that have received preservation treatments. The first is a log structure built in 1914, and later used to support plutonium chemistry research. The other building, constructed at the end of the Manhattan Project, was the location of a renowned criticality accident.

Pond Cabin underwent an exhaustive condition assessment that lead to a formal treatment plan. The assessment produced intensive documentation for the interior and exterior of each log. Also, windows and door openings, daubing and chinking, floors, roof, and ceiling were assessed. Actual treatment occurred the following fall by implementing the findings of the treatment plan. Considerations included visitor safety and the preservation of historic character and integrity in relation to designated periods of significance.

On-site work was completed by the Bandelier Preservation Program in coordination with the NPS Vanishing Treasures Program which specializes in preservation-based training opportunities for various federal agencies as well as non-governmental organizations and individuals. Fieldwork focused on using traditional building skills in conjunction with modern preservation techniques. Holistic approaches to preservation pose a variety of challenges involving access, stakeholder issues, complex historical contexts, and the bureaucratic demands associated with preserving U.S. Military Heritage. This paper examines the role of preservation in encouraging continuity of traditional building techniques within the realm of modern national defense.

White male with short brown hair mustache and goatee wearing a light blue button-up shirt standing by a microphone.
Jeremy Brunette


Jeremy Brunette: Good morning. My name is Jeremy Brunette, and I'm actually a coauthor of this paper, along with J.T. Stark, who is the Head of Preservation at Bandelier National Monument. We've been working together on some preservation treatments at some of the buildings at the park, that I'll get to. I will read a few things so I make sure I get J.T.'s thoughts, as we go through the talk.

But before I get started, I wanted to thank Julie and Robert, because when I first started working at the lab about four years ago, I was told by Ellen McGee, who I worked with at the time, she's since retired, "Hey, we're going to have to do a cultural landscape report." I was familiar with what they were for my thesis project. I was like, "Okay, how the heck are we going to do this?" Shortly thereafter, fortunately, we met Julie, and Julie said, "No, you guys aren't going to going to do this. I can do it." And so we're really grateful that she is doing it and that Robert's doing it. They're bringing their expertise and really giving the park the kind of cultural landscape inventory that it needs.

This project, and this part really is a collaboration, so I want to make that very clear, because we have the big, we have the US Department of Energy, and the National Park Service, so that there are two big federal agencies. Then we've also got the collaboration on a more local level, between Los Alamos National Laboratory, which is managed by Triad National Security and the Bandelier Preservation Program. We're really fortunate that Los Alamos is right next door. We do have Bandelier National Monument, and they've really gotten excellent preservation staff, and we've been able to utilize them. We're really fortunate in that way.

You've seen this map before, but again, this is kind of a unique park, because it is spread out. There are three units, and we're just one unit of these three units. I honestly, I'll tell you, I haven't been to Hanford or Oak Ridge yet. But I do know what we have at Los Alamos, and so that's what we'll be talking about today.

All right, so I'm going to read a little bit, and then I'm going to talk a little bit about a few of these photos and how they relate to things. Los Alamos National Laboratory provides unique challenges for the New Manhattan Project National Historical Park Unit, due to the fact that Los Alamos is an active laboratory, working on many projects related to the United States national defense. That's actually where we're kind of unique, and where a lot of these buildings are located. They're really co-located within high security, active missionaries at the lab.

Due to [inaudible 00:03:02] role in the development of nuclear weapons, there are also safety concerns that are not common in other national parks. Some of these are legacy metals and high explosives that remain at some of the park sites. We have to account for this when we plan for our preservation projects. There's also the significant security component, that blankets all activities at the laboratory. Considering these challenges, Los Alamos doesn't really seem like the kind of place that would be amenable to creating and developing a national park within its confines. Actually when the park was first announced, we did have people that work in some of these active laboratories that were very apprehensive, trying to understand if by having a park here at this laboratory, if that meant that they were going to lose access to do their critical research. We weren't sure how those were going to mold.

But the park really is being successfully developed. We feel like we've got pretty good support from the lab now. As you know, we're basically, about four years into it now. We see that changing, and we're seeing that we're getting more and more support. In this paper we're going to briefly outlined some of those successes we've had in our early preservation. Again, this is basically a brand new park, and things don't always happen quickly.

Gray cinderblock shed with numbers reading 516 and two tall green doors with other smaller structures behind it.
Buildings at V-Site. The high-explosives components of the Gadget were assembled in the building in the foreground

One of the aspects that we have that we deal with in security is that basically all the buildings from here, this way, this whole series of buildings here and structures, these are all, and you can kind of see on the map, they're all kind of in this area here, that area is a high security active missionary at the laboratory. In the park we also have sites of the... park buildings that are in the town site, and then we have TA-18 or Pajarito Laboratory here, and you can see it's kind of far away. One of the things that I'll touch on a little bit more is that this distance from the town site is a big reason why Pajarito Laboratory was used during the Manhattan Project.

A few of these buildings, and really we've got these buildings here. This is Gunsight. These are the two buildings where Little Boy or the gun device was developed and assembled, and then everything else supports implosion. We've got anything from firing pits, we've got implosion diagnostics, we've got these structures here, supported implosion diagnostics. This is a photo here of V-site. This is where the gadget, the high explosive components of the gadget were assembled, before they were taken to Trinity for the test that took place in the High Bay building here.

We've also got the Quonset hut here that I need to mention. The Quonset hut is where the high explosive components of the actual Fat Man device that was sent to [inaudible] were assembled. That's also where the trapdoor method of arming a Fat Man device was developed. And then we've also got just a few other buildings here. This is the one actually is kind of interesting. This is a concrete bowl. You can see it's... hopefully you can see it. It's full of water. The idea with that, this was just kind of kind of a scale model, really. This was a proof of concept test. When they were developing the fat man implosion device, they weren't absolutely sure that it was going to work. We also had the issue that plutonium, which was coming from Hanford, was very scarce and we had very limited quantities of it. There was a big concern, what do we do if the bomb doesn't work, if it's a fizzle, if we get the high explosives explosion but we don't have a nuclear blast?

Well, one of the ideas that they thought they could do was build this concrete bowl, and it all slopes down towards the center of where there's a catchment basin, and then there was a platform above it with a water tank, and that they would detonate the bomb inside the water tank, and then if it didn't work they could capture the plutonium. Unfortunately by the time they got time to test it, they didn't have to build this at Trinity because I can't imagine a scale of something like this at Trinity. It would've been massive.

Again, you've seen this photo before, so I won't dwell too much on it. But even now, you can see this is a little limited. But one of the things that's important about TA-18 is that we have identified this site, because it's not in an active mission anymore and I will go ahead and mention it now. We talked about high security, some of the buildings that were here, the criticality work that was done here. All this work in the 2000s was moved to the Nevada test site and it now sits at the DAF. This area used to be one of the highest security areas at the laboratory, for a number of years. But now because it's largely been decommissioned and it's relatively close to the outside gates, it's the area that we've defined as somewhere where we can hopefully get the public in more often.

Now, we have had public visits here. We're continuing to do them, although right now again it's on a limited basis. Just this year, the site scheduled to host visitors on three different dates. Two of the dates coincide with the April and October dates that the Trinity site is open. We do tours the Friday before Trinity is open and then the other one coincides with Sciencefest, which is a local Los Alamos event. That's a big event for the community every summer. That takes place in July.

Technical Area 18, also one of the most interesting things about it to me, and one of the reasons why I'm really passionate about this site, is that it has basically three different buildings and structures that are Manhattan Project related. But in those three structures we can really kind of tell the whole depth of the Manhattan Project story in one site. It's really a useful location.

There we go. The first building I'm going to talk about, and Robert alluded to it is Pond Cabin, which is right here. This site, this area that we're talking about, before Los Alamos ever existed, back in the 1700s, this site was a land grant. It was known by the 1860s, as the Ramon [inaudible] land grant. He was the one that successfully applied to the United States government to have the land grant accepted as a large chunk of property that was recognized by the US. It's about 22,000 acres. This was a large chunk of property. 1862 Homestead Act, you're talking 160 acres, you could get here if you could get a hold of this, you've got 22,000 acres. This was a valuable piece of property.

Actually some of the buildings that we see here, in particular, this two story structure here, was first built as a ranch house. Because we're in Texas, I will mention a gentleman by the name of WC Bishop, who was a cattleman from here in Texas. He had actually moved his cattle to the plateau. He was leasing the land grant and he ran his cattle there on the land grant for about eight years. Following a couple of years of harsh winters, he had a big die-off of this herd, and so he turned around into the back to Texas.

Historic photo – five people in front of a log and stone cabin surrounded by tall pine trees.
Cabin built by Ashley Pond in 1914

The cabin itself was built in 1914 by Ashley Pond. Ashley Pond was from Detroit and he had investors who were his childhood buddies, who were also from Detroit. As Robert alluded to, this was kind of a rod and gun club. The idea was, this would be a dude ranch. They could bring people from the East. One of the things that they were most interested in bring people out here to do was hunt mountain lions. That was kind of the big attraction. Even to the day in Los Alamos, they say every canyon has a mountain lion, so to this day we still have a lot of mountain lions, on the plateau. But it was a big draw. We also have a large elk population. The cabin itself was built to serve as Ashley Pond's office for this Pajarito club.

Here's another view of the cabin. The cabin actually served as Ashley Pond's office for only about two years. After about two years, he got frustrated because he had big plans for the site and wanted to do a lot of a development, kept asking his investors for money and they said, "You know what, we're not getting the people out there. We don't see this as a moneymaking operation. We're not going to give you any more money until you can get more people." So he said, "You know what, that's it, I've had it." Kind of broke up with his childhood friends and moved on, found other investors, and developed the Los Alamos Ranch School up in Los Alamos. Actually in Los Alamos, if you ever visit, there is Ashley Pond, which is right next to the Ranch School, named after the same gentleman, Ashley Pond.

The cabin, just because Ashley Pond moved away didn't mean that the cabin didn't continue to be used. Following Ashley Pond's leaving the land grant continued to change hands. One of the major players that really affected the landscape that we had on the Pajarito Plateau was a gentleman by the name of Frank Bond. Frank Bond was a sheepman. He had stores in Espanola, which is in the valley below Los Alamos. He would basically finance people, he'd sell them sheep. Largely Hispanic people from the local Hispanic community, they would go up and run sheep all over the plateau. This large amount of sheep led to a lot of environmental degradation, a lot of damage. We have pretty thin soils on the plateau, and that many sheep just overgrazed the whole area and it really fell in into a bad state.

In the 1930s, the property was taken over by the Soil Conservation Service, and then it was transferred actually to the Forest Service, before the federal government took it over in 1943. Why are we talking about this cabin so much, when we're talking about the Manhattan project? Well, this cabin actually did play a role in the Manhattan Project with Emilio's Segre and his radiochemistry group. What they did really was one of the milestone events of the laboratory in many ways. Emilio Segre, he's this gentleman right here, in the photo and that was his group. That photo was taken up in the town site area, up in the main laboratory area. They were using radiochemistry to study the properties of plutonium. What they wanted to know was, was plutonium going to work in a gun device?

When the scientists first came to Los Alamos, Robert Oppenheimer's big idea was that they would build two, what they called gun type devices, which is what Little Boy was, where you take one subcritical mass and you fired it at another subcritical mass. When they make the connection, basically you get a big boom. That was kind of the idea. We had uranium, which Little Boy used, coming from Oak Ridge, and then we had this big plutonium facility that had been built at Hanford, where they were making plutonium. We'd spent millions of dollars on this plutonium facility, we're starting to get plutonium, and all of a sudden they're saying that it won't work in the type of device that they had planned.

We had a gentleman by the name of Seth Neddermeyer that had kind of been playing with this idea of implosion, which is an inward explosion, where essentially you would take your subcritical mass, your plutonium pit, and you would take high explosives, and you would essentially squeeze it to the point where it went super critical and you would get an explosion, during high explosives. That was something that had never been done before. The high explosives that we had at the time were pretty crappy, and we just didn't know much about plutonium, because it's a brand new metal.

Through Segre's research, and this is a picture of one of his experiments, the experiments took place in another cabin, besides the Pond Cabin. But they use the Pond Cabin largely, we said, sleeping, office quarters, probably storage. One of the funny stories I'll tell, I'll throw in, and I'm kind of taking a lot of time on this. But this was a remote area, and the reason that they use a remote area is this equipment that we see here was really sensitive. It was sensitive to electricity, so you had to have it away from a lot of power sources. Also in town, we had constant construction, ground shaking, that sort of thing. That sort of effect would have had a negative effect on his experiments. That's why they chose the Pajarito Canyon to do this experiment.

Emilio Segre's research... I'm sorry, I'm getting off the track. Essentially they determined that the properties of plutonium wouldn't work, so that led to the total reorganization of the laboratory. Essentially 15 months, is what we took to figure out implosion, which led to a large development. The cabin also had an early Cold War component. This gentleman in the photo here who was Dwight Young, and the picture you see here was his bedroom. He actually used the cabin from 1946 to '52, as kind of his living quarters. He worked there at the laboratory and he lived here. He was a little eccentric I think.

So the Pond Cabin, I just wanted to point this out. The Pond Cabin is kind of tucked in over here, and you can see there's a fence. It's kind of fenced off. You can see the development of laboratory. The Pond Cabin is really kind of a survivor. I like to call it a survivor, because it was built in 1914, all these things happen in it. Fortunately when they were developing the site, somebody must have found it interesting, because they never decided to tear it down. They just kind of developed right around it, and it just kind of sat there. It did undergo some restoration in the 1980s, so there was some effort put into it.

The next thing I'm going to talk about is the Slotin Building. This is a picture of the Slotin Building. Robert actually had a better one. This is one of my favorite photos. This is really during its period of significance, which is essentially, just a matter of minutes. This is kind of what the Slotin Building looked like. Here's the building, there's a covered passageway here, another laboratory here. The Pond Cabin is kind of sitting over here, already outside of the fence. This is the cabin where Segre did actually the radiochemistry research. But notice the security component. We keep talking about security. Security, it's an issue today. It was an issue then. You've got a portable guard shack here. You've got a portable guard shack here. You've got a guard tower here, right next to the structure.

So, the Slotin Accident. The Slotin Accident took place on May 21st in 1946, and this was following a similar criticality accident that had happened to a gentleman by the name of Harry Daghlian, on August 21st of 1945. In the Slotin Accident, essentially Louis Slotin was a Canadian physicist. He was really the premier criticality expert in the world at the time. But he was getting ready to leave the lab, and he was training his successor who was a gentleman by the name of Al Graves. So Al Graves was kind of getting a tour of the site and he said, "Hey, can you show me a criticality experiment? Can you show me how this works?" And so Lewis Slotin said, "Yeah." There were total seven people in the building. One of them was a guard, because you had to have a guard if you had special nuclear material out of the vault.

Lewis Slotin set up the experiment and you've got two beryllium hemishells, and the plutonium pit would have been in the middle. Typically there were spacers. We don't see spacers in the photo because we think he actually neglected to use them during this. The idea of the spacers is that if you set that top hemishell down, it would keep the distance just right to where you wouldn't have any sort of criticality accident. Notice Lewis Slotin's thumb is in a hole on the top of the top hemishell. He would kind of lean that top hemishell down on top of the sphere, and then he had Geiger counters and different sensors that would make noise. It was kind of a feel thing, a sense thing. They could kind of get it as close to critical as they wanted.

Well, this day during this experiment, the screwdriver that he's holding here slipped, and the two hemishells went together. There was a blue flash, and he threw that top hemishell off and Lewis Slotin unfortunately passed away nine days later from his injuries. There were seven people in the building, other people had various reports of injuries. But Lewis Slotin was the only one that died as a direct result of this accident.

We also have battleship bunkers, which we've talked about a little bit. I'm running short of time. These really supported the Creutz Test, specifically building 18-5. The Creutz Test was basically a test completed two days before Trinity, where they were looking at... basically, this was the only full-scale high explosive implosion test that was done. Initial results on the data said that it didn't work. Luckily, we had Hans Bethe there. He was able to re-look at the data, said, "Yes, it did." Trinity went off as planned. This is actually a photo inside of that bunker, the instrumentation. It also held people.

Now, let's get to the preservation aspect. So I'm working with, with Bandelier National Monument, the first project that we tackled was the Pond Cabin, and it hadn't had any work done on it for about 30 years. It was in pretty bad disrepair. Oftentimes there were rodents inside when I would enter, that sort of thing. The first thing that we did was a condition assessment. Bandelier's group came out, they did intensive documentation, made these detailed illustrations. They actually did a log-by-log assessment. They looked at every single log. They actually were able to find the original daubing, looked at the structural integrity of the unit, looked at the windows and put together a treatment plan.

Following the treatment plan, we were able to partner with Vanishing Treasures, out of Santa Fe, and set up actually a workshop on the site. At the workshop we actually brought students from various agencies around the state, and we're able to teach them in some of the traditional building techniques, and actually have them participate in a treatment plan. It was really something that for a high security area, like we are at Los Alamos, this was a pretty big deal that we could get the unwashed public onto the site to actually conduct this sort of project.

One of the things that they did, that was really important is wall stabilization. Here you can see they're actually straightening some of the walls. They jacked up some of the walls. You'll see the students participating in this. They also did window and door opening repair, stabilized the ceiling, did log crown repairs. They repointed and daubed all the joints, and then they also replaced the exterior, some of the deteriorated logs. Here we just kind of see the cabin, see all the students out there. The repointing between the logs, required removal of, there was an incompatible cementitious mortar that had used in the late '80s they had to remove. Then they went back in and they found some similar mortar, just using sand and lime, and they were able to make a new mortar, and it matched pretty well.

Another big thing that they had to do is like I said, we had some deteriorated logs. One of the issues that we have is if you take out a whole log, the interior of the log, if you put it back, you have this white, just bright log, that the interior, that looks funny and because it's not exposed to the sun, it takes probably 100 years to age to where it would ever look even somewhat remotely close to what the original logs look like. They actually determined that the best thing to do was to take off basically exterior logs, and create a veneer. They used traditional hand tools to create this veneer. They had to be the same division. They really ripped these logs in half with nothing more than hand-axes, so it really was all just all handwork. Was pretty impressive what they're able to do. Here's another picture of them getting a log veneer a little closer.

A man wearing a hardhat using an axe to carve a notch in a log.
Log specialist Al Williams prepares corner notch of a replacement log using traditional tools only.
These were cut to length with cross saws and then shaved down with draw knives, so the other side they actually used a draw knife to shave it down to the appropriate size.

And then they also had to take off the old exterior half of the logs. What you can see here, they've got it kind of prepared, and they're drilling holes. They essentially, what they did is they pulled off this exterior, and then they drilled holes and they use fiberglass dowel, and they drove it into the holes that they drilled, and then they epoxied the new veneer on, so it can be replaced if it ever needs to be. Here we see another picture of them prepping the exterior of the building. Here we see those fiberglass dowels that they're inserting in place. You can see they're about that size, and then they would just epoxy the outer section of it, and installed them.

Here you can see them putting one of the log veneers on. As you can see in this photo, and what I had kind of alluded to, they kind of standout like a sore thumb. Following this, they used some natural dyes and kind of dyed the logs, so that they blend in. They don't stand out quite so much.

The other thing that they did that was a big project was replaced log crowns. A lot of logs showed significant deterioration during the condition assessment. The crown, as you can see in this case, was pretty much gone. So this was the area of the log that overhung the joints. They had to figure out a way to replace these. They under did a similar project. To alleviate the structural instability this particular condition causes, they removed only the deteriorated segments of the crown, and they fabricated a replacement that exactly matched the dimensions and shape of the original. To do this, we used historic photos, measurements, and also with just what we found at the site. Here they are preparing some log ends, using just chisels and draw knives.

Here, they also use fiberglass rods in this case. They would drill into the remaining log, and they would insert these fiberglass rods, and then the fiberglass rods would hold the replacement log ends, and they were epoxied in place. Here's Mary Webb from the program at Grand Teton National Park, and she's installing one of the log ends. The students got to participate in this as well. You can see here, they're pretty excited. They got their first log end fitted. This is kind of a fun photo.

The other thing that we undertook as part of this project is Slotin Building, Bandelier National Monument did a window restoration. As part of this project they removed the window sashes to analyzed the paint. They were able to match the paint, repainted them with oil-based paints, and then they worked on the window frames onsite, and repainted them as well. That was also another big project, a lot of logistics with lead issues and that sort of thing we had to deal with.

I'll just read this last part. Lanel Historic Buildings Program strives to preserve the historic buildings located within the boundaries of Lanel. We formed a really good partnership with the preservation program at Bandelier National Monument. Without the support and coordination of the Vanishing Treasures Program to bring in log preservation specialists, and they also set up the workshop that allowed us to get a lot of this work done on the Pond Cabin. If this hadn't been done, the cabin likely would have suffered greatly, and if we would have tried to tackle this sort of project at the lab with our resources, it certainly would not have gone as well. It wouldn't have been the caliber of project that we got. A big part of this was overcoming logistical hurdles, as far as how do we get people on site, that sort of thing.

We've gotten a lot done. We're planning continued collaboration on structures and buildings in the high security areas. That's going to be a little more complicated as far as how we get National Park Service staff out to areas that are in high-security. That will take a lot of coordination with us at Los Alamos, and we think that this continued partnership is going to ensure that the buildings and structures at the Los Alamos unit will continue to undergo a thoughtful and well-formed analysis and preservation, and that we'll be able to successfully protect these nationally significant buildings for future generations. Thank you.

Speaker Bio

Jeremy Brunette manages the Historic Buildings surveillance and maintenance program at Los Alamos National Laboratory. He helps to manage over 2,000 identified cultural resources including 47 buildings (including Manhattan Project National Historical Park structures) that are identified as candidates for preservation due to their historic significance. Jeremy Brunette has worked for Los Alamos since May of 2015 and his research interests include historical archaeology, the archaeology of the Great Plains and the Southwest, Unites States military history, as well as Spanish and French colonial history. Topical interests include Manhattan Project and Cold War history and archaeology, homesteading, architectural history, and preservation issues.

J.T. Stark manages the Preservation Program at Bandelier National Monument in Los Alamos, New Mexico. He directs several preservation crews each year tasked with documenting and preserving the park’s large Ancestral Pueblo archeological sites and the Civilian Conservation Corps National Historic Landmark District. In addition to his duties at Bandelier, J.T. collaborates with Los Alamos National Laboratory staff to accomplish preservation work at the nearby Manhattan Project National Historical Park.

Last updated: June 2, 2021