ICYMI: Counting up INL’s reactors

Starting with the name: The site that now operates as Idaho National Laboratory has seen its purpose—and its name—shift over the decades. Its story starts in 1942 when, in between the Idaho towns of Blackfoot, Arco, and Idaho Falls, the U.S. Navy established the Naval Proving Ground in support of coastal and island naval bases built in the late 1930s as tensions mounted toward World War II. The mostly empty land was well-suited for ordnance testing and research.

Then, in 1949, following a recommendation from Argonne National Laboratory Director Walter Zinn to build a facility in a remote location for testing reactors, the Atomic Energy Commission chose the Idaho site for the National Reactor Testing Station and developed plans to spend $500 million on reactors and research facilities. After a competition among all the towns surrounding the site, Idaho Falls was chosen as the headquarters for the NRTS that spring.

Over the next two decades, Argonne National Laboratory was heavily involved with the NRTS, building numerous test reactors and extensive research facilities. The campus was widely known as Argonne-West through the remainder of the century.

Meanwhile, in 1974, the NRTS was renamed Idaho National Engineering Laboratory (INEL). In another twist, in 1997, INEL became Idaho National Engineering and Environmental Laboratory, or INEEL.

Finally, in 2005, after operation of the laboratory changed hands from Bechtel to Battelle Energy Alliance, Argonne-West and INEEL merged to create Idaho National Laboratory as we know it today.

Over the course of these many changes, the site we now refer to as INL was home to many of the most important reactor experiments in nuclear history. Whether a given reactor started or operated during the days and on the sites of NRTS, Argonne-West INEL, INEEL, INL, or some evolving mix of the lot is a question that can be far more difficult to answer than it is important. Suffice to say, INL’s list chronicles the reactors that have been built within the 890-square-mile site now called Idaho National Laboratory. Thus, for the remainder of this exploration, only the term INL will be used.

The outliers: Over the past several years, INL has maintained a historical webpage titled “INL’s 52 Nuclear Reactors.” As recently as last week, that list was described on INL’s page as including each reactor that has been “built and operated” on INL’s site since 1949.

There’s one problem, though: two of the reactors on INL’s list never actually entered operation. Per the parameters originally set out in INL’s own description, these reactors should not be included in the official count.

Those two reactors were called the Experimental Organic Cooled Reactor (EOCR) and the Experimental Beryllium Oxide Reactor (EBOR). The stories of these projects reflect a multifaceted approach to nuclear research early in the nuclear industry.

Explaining EOCR: In 1957, INL brought the 15-MWt Organic Moderated Reactor Experiment on line. According to INL, OMRE “demonstrated the feasibility of using a liquid hydrocarbon as both coolant and moderator. The waxy coolant was considered promising, because it liquified at high temperatures but didn’t corrode metal.”

EOCR was intended to be a scaled-up, 40-MWt experimental reactor building on the research conducted with OMRE. Construction of the reactor was completed in 1962, but it was never taken on line. Per INL, this was because “Atomic Energy Commission leadership decided the concept would not meaningfully improve nuclear power plant performance.” The archives of Nuclear News provide deeper insight.

In the January 1963 issue of NN, an article titled “Organic-Reactor Program Is Curtailed” (p. 28) agrees with INL’s statement but adds that the AEC’s decision was also motivated by the Packaging Corporation of America deciding not to submit a proposal for an organic plant that would have generated both power and process steam. “Interest in such a plant was expressed to the AEC in March 1962 jointly by the corporation and Atomics International” but did not ultimately develop into a project proposal.

The story of U.S. organic reactors did not end with the cancellation of EOCR. What came next was the Piqua nuclear power facility, which has already been chronicled elsewhere on Newswire.

Explaining EBOR: The story of EBOR is in many ways similar to EOCR’s. INL’s official list explains that its purpose “was to develop beryllium oxide as a neutron moderator in high-temperature, gas-cooled reactors” and goes on to say that “the project was canceled in 1966 as graphite gained favor as a moderator.”

In the archives of Nuclear News, EBOR appears for the first time in the February 1963 issue (p. 32). There, NN writes that EBOR was “in association with the advanced gas-cooled maritime reactor” and had a completion date of “about the end of next year.”

The next significant mention of EBOR came in the October 1964 issue (p. 75), where NN recorded that the reactor was intended to “demonstrate the technology of BeO as a moderator for a class of gas-cooled reactors applicable to central station and marine power plants.” Operation was delayed to early 1965, and NN added that the 10-MWt reactor would “operate with a helium outlet temperature of 1300°F.”

More details were offered in the February 1966 issue (p. 36). There, the reactor is described as having a “long, narrow core (6 ft. long, 2 ft. square),” among many more technical specifications, and an explanation of beryllium’s potential favorability for small reactors.

One year later, in the February 1967 issue, EBOR made its last significant appearance in an article (p. 9) reporting that the Atomic Energy Commission had terminated the project. The article’s explanation for the decision mirrors the explanation offered by INL today, though NN added that cost and time concerns also influenced the AEC’s decision.

The confusing twist: INL’s official reactor list had long sat at 52 (or 50, by the NN count). However, in recent weeks, a flurry of new reactors have reached criticality at the site—Antares’ Mark-0, Deployable Energy’s Unity, and Aalo Atomics’ CTR. This has bumped the official count now up to 55 (or 53, in our estimation).

It seems that, in returning to the list to add these new reactors, INL decided it was time to reorganize the page, recategorizing the reactors and—critically, for this discussion—deleting the qualification that the list only counted reactors that were “built and operated.”

This subtle change was rolled out in between the writing and review of this piece, turning the thesis of our piece from the simple “INL’s list is technically incorrect by their own defined standards” into the much more confusing “INL’s list used to be technically incorrect by standards they have now eschewed.”

Nonetheless, without much ground left to stand on, the NN team maintains that EOCR and EBOR should not be counted on the official list, and that INL’s official reactor count should now be considered 53, not 55.

One more reactor: This story has one more thread to pull. When Antares took Mark-0 critical, many people made the vague statement that it was the first criticality at INL in decades, leading to the obvious question: Before Mark-0 started up, what was the most recent reactor to enter operation at INL, and how long was the gap?

The answer to that question is the Neutron Radiography Reactor (NRAD), which, according to a brief article from the December 1977 issue of NN (p. 49), entered operation on October 12, 1977.

In a follow-up news brief the next month, NN reported (p. 21) that NRAD (which is still running today) is a 250-kW TRIGA reactor “that passes a beam of neutrons under the main examination cell of the HFEF [Hot Fuel Examination Facility], where it meets a vertical, gastight specimen tube that descends from the floor of the main cell. Formerly, experiments had to be sent by cask to the TREAT reactor for radiography.” A second beamline from NRAD is routed to INL’s North Radiography Station, which provides “radiography and tomography capabilities of nonirradiated and transient irradiated specimens,” according to INL.

The gap between NRAD and Mark-0 was nearly 49 years. This fact leads to an interesting conclusion: Considering NRAD came on line when the INL site was still divided between Argonne-West and INEL, technically, Mark-0 is INL’s first ever reactor.