HFIR’s fuel conversion seeming less likely

This is a follow-on column to earlier post on the HFIR:

hfircalifornDespite its age, the High Flux Isotope Reactor is considered one of Oak Ridge National Laboratory’s most valuable assets.

The High Flux Isotope Reactor was built in the 1960s. That’s pretty old by reactor standards. But the HFIR has undergone a significant makeover in recent years — replacement parts, infrastructure upgrades and new research capabilities — and lab officials have stated their intention to operate the 85-megawatt reactor for decades to come.

It’s apparently good to go.

One lingering question: When will Oak Ridge National Laboratory convert the reactor to use a lower-enriched uranium fuel?

Unlike commercial power reactors, which use uranium fuel with about 4 percent U-235 (the fissionable isotope), ORNL’s research reactor uses super-enriched uranium fuel that’s reported to be 93.8 percent U-235. That special fuel helps the reactor do its job, producing neutrons in highly concentrated streams that allow scientists to explore materials in exquisite ways that reveal properties and structures. The highly enriched uranium is also important to the production of radioisotopes for medicine, industry and research.

The down side of using uranium so rich and fissile is its potential for being used in nuclear weapons — and thus coveted by those who would seek to build weapons of mass destruction.

Nonproliferation programs have been a priority of the Obama administration, and one of the areas of emphasis has been to convert HEU-fueled reactors around the globe to use low-enriched uranium fuel (less than 20 percent U-235) to eliminate the weapons capability and ease the threat of nuclear terrorism.

The fuel conversion of the High Flux Isotope Reactor keeps getting pushed deeper into the future.

Tim Powers, director of ORNL’s Research Reactors Division, said there are two unique design features about the HFIR that make it a difficult candidate for fuel conversion: the “radially contoured fuel zone” and inclusion of a neutron absorber in some of the fuel plate.

Nobody, of course, wants to do anything that will reduce the reactor’s capabilities.

At one time, the projected conversion date for HFIR was 2014, and then it was postponed until 2020, and now — according to a response from Powers — the conversion of HFIR to low-enriched fuel is scheduled for 2030.

The Oak Ridge reactor will reportedly be the last U.S. reactor to undergo the change.

And, given the age of the reactor, it seems less and less likely that the HFIR will ever be converted, although no one says that officially.

SAFETY: SafetyFest TN, the biggest safety event of the year in Oak Ridge, with lots of free training classes, exhibits and speakers, is coming up soon — Sept. 8-12 — and the timing may be particularly good.

A couple of accidents last week at the Y-12 National Security Complex, each of which resulted in an employee being hospitalized, brought safety into the spotlight once again and perhaps made more people aware that safety is not a seasonal priority, a sometimes thing or just a way to act when the boss is watching.

It’s all day, all the time. It’s something you do for yourself, but it also affects others.

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About Frank Munger

Senior Writer Frank Munger covers the Dept. of Energy's Oak Ridge facilities and many related topics — nuclear weapons, nuclear waste and other things nuclear, environmental cleanup and science of all sorts. Atomic City Underground is, first and foremost, a news blog, but there's room for analysis, opinion and random thoughts that have no place else to go.