The Other Side of the Creek: The Atomic Age at Stanford

Editor’s note: “The Other Side of the Creek” is a series designed to capture the life and spirit just beyond San Francisquito Creek — the shared landmark separating Menlo Park from more southern communities.

Introduction

There are corners of Stanford where the ground has held more than one kind of future. The Ryan Lab is a prime example. Originally established in 1926 for spectacular high-voltage electrical testing, it was later retrofitted in the 1950s to house a “pool-type” nuclear training reactor. Today, the site serves a much quieter purpose as the Ryan Court residential community.

First Life



There are corners of Stanford where the ground has held more than one kind of future. One of those futures began in fire-white voltage, and later — briefly, quietly — shifted into the blue-glow vocabulary of the Atomic Age.

In its first life, the Harris J. Ryan High Voltage Laboratory was built for spectacular electrical work. Named after a Stanford engineering pioneer who shared the Edison Medal ranks with Nikola Tesla and Alexander Graham Bell, it opened in 1926 as the world’s largest university electrical facility. Its primary mission was ambitious: to solve the massive engineering challenges of transmitting electricity over hundreds of miles to power the booming American West.

The sheer power of the facility demanded an industrial, cavernous, hangar-like structure, simply to give its giant transformers enough clearance to prevent millions of volts from accidentally arcing into the walls. At its dedication, Stanford proved the lab’s capabilities by staging a stunning public demonstration around its 2,100,000-volt test station, generating an artificial lightning bolt across a 20-foot gap — a world record for commercial-frequency voltage at the time.

Transformation To Atomic Campus

By the mid-1950s, Stanford’s Mechanical Engineering Department began building a nuclear program under Professor George Leppert. In 1958, the old high-voltage lab — a space originally scaled for artificial lightning — was remodeled to support nuclear teaching and research. The program started with a subcritical assembly, captured in a 1958 university centennial photo of Leppert and graduate student Gary Vliet, marking a profound period of transformation.

The detail that still surprises Peninsula readers is not the concept of a teaching reactor —it’s the location. This was not a distant, heavily guarded test site in the desert. It was right on Stanford’s campus near Palo Alto, housed in a building that already held decades of electrical history.

Tapping into the region’s emerging commercial atomic industry, the reactor was manufactured just down the road by General Electric’s Atomic Power Equipment Department in San Jose. 

Filed in November of, 1959, the federal record became explicit: the Atomic Energy Commission issued Facility License No. R-60, authorizing Stanford to possess and operate a 10-kilowatt reactor facility on campus. See construction permit.

A “pool reactor” is exactly what it sounds like: the core is submerged in a deep tank of water. This specific design explains why the government allowed a nuclear core on a bustling college campus. Operating at a maximum of 10 kilowatts (thermal)—roughly the energy used by a couple of household electric ovens—it required no pressurized containment domes or massive cooling towers. The pool provided cooling via natural convection and served as a highly effective radiation shield, creating a fail-safe, low-power environment specifically designed for student training.

By the mid-1960s, this wasn’t just a novelty bolted onto campus; it was a core part of Stanford’s evolving engineering footprint. The 1926 structure now held labs, classrooms, and offices for the Nuclear Division. It also hosted a curriculum that is astonishing by modern standards. In 1965, Professor Paul Kruger launched Stanford’s first course in nuclear civil engineering, funded via a training grant from the Public Health Service and the AEC. He brought in scientific titans like Edward Teller and Nobel laureate Willard Libby as guest lecturers. Aligning with the federal “Project Plowshare” [related: https://apps.dtic.mil/sti/tr/pdf/ADA396463.pdf] initiative of the era, Kruger’s civil engineering students were literally studying the feasibility of using peaceful, tactical nuclear explosions for massive earth-moving projects, like carving out artificial harbors or new canals.

Stanford’s facility fit a wider national pattern that reads as almost unbelievable today: midcentury America eagerly placed training and research reactors on campuses to rapidly build a nuclear workforce. At the national peak, some 75 colleges and universities housed their own reactors.

Yet, the Atomic Age at the Ryan Lab was relatively brief. The Stanford Pool Reactor operated only until 1973 before it was permanently shut down.

The Quietest Ending

During the atomic optimism of the 1950s and 60s, it was entirely common for major research universities to house small-scale nuclear reactors for training students and running experiments. At the national peak, more than 70 campuses held them. However, over the last few decades, the vast majority of these facilities — like those at UCLA and Cornell — have been permanently shut down and dismantled. 

Maintaining aging nuclear infrastructure became incredibly expensive. Furthermore, as the federal government pushed to remove weapons-grade Highly Enriched Uranium from civilian sites, the massive costs of converting the fuel, combined with the rising security risks and regulatory burdens of housing radioactive materials on a bustling college campus, simply outweighed the scientific benefits for most schools. While a few rare holdouts like MIT managed to adapt and keep their reactors running, Stanford’s facility joined the wave of closures. See the Notice of License Termination & Demolition from 1988.

And what is there today? Housing — specifically, Stanford’s on-campus residential fabric in the Ryan Court area. Stanford’s own housing listings show the quiet community here: “Ryan Court (Stanford Rental Homes).” The creek corridor is still the geographic “tell,” but the lab itself is gone, finally demolished in the late 1980s. There is no monument, no dramatic marker, no historic plaque — just daily domestic life where high voltage once arced and, later, a small licensed reactor once operated.

That’s the quietest ending: a hangar-like building that held 2.1 million volts, then a 10-kilowatt pool-type reactor, entirely replaced by a campus neighborhood most people pass without a second thought. If you have memories—an open house, an old professor’s aside, a parent who worked nearby, a half-remembered line about “the reactor pool”—that’s the material local history depends on. The Peninsula’s past often isn’t loud. It is found in the things that hummed quietly, hidden inside the buildings everyone assumed they already understood.

Top photo: “Stanford University, 9-18-26, Dr. H. Ryan’s Electrical Laboratory” typed on the back.

Second photo: “E 178 Condenser connections at the laboratory looking directly at the building” typed on the back. The hangar-like electrical engineering facility was built for very large high-voltage experiments. Contemporary Stanford descriptions note it was located near “Frenchman’s dam” on/along Stanford Avenue, on the campus edge toward the foothills.

Third photo: Here is a rare view of Stanford’s Nuclear Technology Laboratory, in the former Harris J. Ryan High-Voltage Laboratory in 1961.

Fourth photo: Engineering professor George Leppert (right) and graduate student Gary Vliet take measurements in Stanford’s subcritical nuclear assembly, 1958. The apparatus, which operated like a reactor but could not sustain a chain reaction, was located in Stanford’s Nuclear Technology Laboratory.

All photos courtesy Stanford University Libraries, Department of Special Collections and University Archives.