Category Archives: HFIR

ORNL reactor at full power after major maintenance

hfirbay-thumb-620x465-26505.jpgView of the high bay area of the High Flux Isotope Reactor from the main control room.

Oak Ridge National Laboratory’s High Flux Isotope Reactor returned to action this morning and achieved full power (85 megawatts) shortly after noon. The research reactor underwent major maintenance and upgrades during the 80-day outage — the longest of the year — and workers in the lab’s reactors division apparently achieved most if not all of the desired activities. Continue reading

Imagine that: a nuclear reactor for less than $15M


When the High Flux Isotope Reactor was originally proposed in the late 1950s, the estimated cost was about $12 million. When it built in the early 1960s, the actual price tag turned out to be $14.7 million (that cost included the 100-megawatt reactor’s cooling tower). Fancy that. Decades later, the High Flux Isotope Reactor is still operating and — according to Oak Ridge National Laboratory — the reactor now has a replacement value exceeding $1 billion. The above photograph shows construction in 1963. (Department of Energy archives)

HFIR: 50 years old and going strong

FullSizeRender (3)Michaele C. Brady Raap, president of the American Nuclear Society, chats with Johnny Moore, manager of the Department of Energy’s site office at ORNL, at Monday’s ceremonies honoring the High Flux Isotope Reactor.

Oak Ridge National Laboratory’s High Flux Isotope Reactor officially became a part of nuclear lore Monday when it was designated a Nuclear Historic Landmark — joining an elite list that includes Chicago Pile-1 at Stagg Field, the world’s first nuclear reactor.

Unlike most of its 75 cohorts on the list, the 50-year-old High Flux Isotope Reactor not only has an operating past; it also has a future.

“I believe in my heart of hearts it’s got another 50 years in it,” Tim Powers, director of ORNL’s Research Reactors Division, said during ceremonies at the reactor complex east of the laboratory. Continue reading

No. 6

FullSizeRender (7)Oak Ridge National Laboratory now has six facilities that have been designated Nuclear Historic Landmarks. According to Michaele C. Brady Raap, the president of the American Nuclear Society who was in town to recognize the High Flux Isotope Reactor, ORNL has more nuclear landmarks than any other site. In addition to HFIR, the landmarks are: Oak Ridge Electron Linear Accelerator (ORELA); Molten Salt Reactor; Building 3019; Graphite Reactor and the Tower Shielding Facility. Following the ceremonies this morning, participants — including a number of retirees who previously worked at the ORNL research reactor — gathered for a group photo.

He’s back . . .

FullSizeRender (11) Thomas Zacharia, who recently returned to Oak Ridge National Laboratory as deputy lab director for science and technology, was at this morning’s ceremonies recognizing the 50th anniversary of the High Flux Isotope Reactor and its designation as a Nuclear Historic Landmark.

ORNL’s research reactor returns to action following upgrades, repairs, maintenance


DOE photo

Tim Powers, Oak Ridge National  Laboratory’s reactor chief, said the High Flux Isotope Reactor resumed operations on Tuesday (Jan. 13), following a 32-day outage for maintenance and repairs.

Powers said the maintenance period was a little longer than usual because it took place over the holidays. The ORNL official cited several tasks that were completed during the outage.

Among them: Continue reading

HFIR’s fuel inventory at historic low

The High Flux Isotope Reactor, a key research facility at Oak Ridge National Laboratory, has the lowest fuel inventory in its history. And that’s saying something for a nuclear reactor that’s been in business since the mid-1960s.

hfirAfter the ORNL reactor is refueled for scheduled start-up on Jan. 13 (it’s currently shut down for maintenance), there will be only six fuel assemblies available for future use. That’s not much considering the fuel cycle for HFIR is only 23 days, which means it has to be refueled about once a month.

Mind you, the HFIR doesn’t use just any old, off-the-shelf nuclear fuel. The hundreds of intricate and complex fuel plates that comprise the reactor’s nuclear core — and provide remarkably concentrated streams of neutrons for material experiments and production of radioisotopes — are made with highly enriched uranium. That’s very, very enriched uranium, consisting of 93.8 percent U-235, the fissionable isotope of uranium. Because the uranium is bomb grade, special approvals are involved with lots of security. Continue reading

Running experiments at SNS, HFIR

hfirbayOak Ridge National Laboratory’s two neutron sources — the Spallation Neutron Source and the High Flux Isotope Reactor — were restarted last week. The HFIR returned from its scheduled maintenance and refueling out, while the SNS was brought back online after a series of problems.

Ron Crone, ORNL’s associate lab director for neutron sciences, said Monday that both were doing fine and running experiments. Continue reading