Insider stories from ORNL’s unique test site

I got a lot of response from a recent piece on the Tower Shielding Reactor and the many projects carried out at the ridge-top test site in Oak Ridge.57711-001

Among those with stories to tell was J. Wayne Paul, a former field engineer who worked at Tower Shielding for much of his career. “I was intimately involved with most everything that occurred there for 34 years (1960-1994),” Paul said via email.

Paul worked with the operations staff, researchers and folks from outside agencies to assist in getting the necessary hardware to carry out the many — and varied — projects.

“Some of the unclassified projects consisted of constructing fallout shelters with varying concrete thickness exposed to the reactor at elevation, fabricating some huge sodium-filled tanks to simulate the coolant lines of the Clinch River Breeder Reactor, and the construction of a separate reactor handling system and control area for the SNAP 10 studies to test the effectiveness of the ‘shadow shield’ for the space program reactor.”

Paul said his career was both interesting and rewarding.

He also clarified my earlier report, which said that the towers used to hoist the reactor and other materials were 200 feet tall. He rightly noted that the towers themselves were actually 315 feet high, enabling the reactor and experiments to be conducted at 200 feet in the air.

I asked Paul if he would share some anecdotes from his time at Tower Shielding, and he was kind enough to oblige with a couple:

—– “During construction of the large concrete drop pad used in the shipping cask drop tests, a filming crew was on site to document the project. The pad extended about 15 feet below the surface and was tiered like a birthday cake, with the largest area deep, and the smaller at surface level. Fresh concrete was poured and at surface level a large thick steel plate was placed in the center for cask impact.

“The film crew director looked like a Hollywood director running around with a megaphone and visor. Giving directions to his crew, he cut across the corner of the pad and went in knee deep with one leg into the fresh concrete. He didn’t miss a beat, stepped out and continued directing as if nothing had happened, with fresh concrete up to his knee and all over his shoe. A comical sight.”

—- “The SNAP 10 reactor used in the shielding studies at (Tower Shielding Facility) was designed by Atomics International and assembled by ORNL at TSF. The reactor’s cooling system medium  was an eutectic mixture of NaK (sodium-potassium), which is highly reactive when exposed to air.

“After assembly, the reactor was charged with the NaK coolant and sealed. This process involved a charging ‘cart,’ which AI had designed and used at their lab on previous reactors. The cart was an assembly of piping, pumps, and condenser unit to trap out any impurities. It was shipped to TSF and an AI engineer was on board to assist with instructions on its use.

“It was placed in a storage building at TSF, and the AI engineer wanted to inspect it to make sure it was ready for use. He wanted to open some valves to be sure the system had no residual coolant in the pipes. I accompanied him along with a pipefitter to the storage building. He instructed the pipefitter to open a certain valve so he could look into the pipe. After confirming his direction, the valve was opened while he was face to face with the end of the pipe. The cart had been sealed and charged with a low pressure
nitrogen to prevent any reaction.

“Poof! There was residual NaK in the cart, the engineer had NaK on his clothing, a few specks on his face. We did a quick assist in getting him out of his clothes which were smoldering. There were no burns on his skin.

“The daily log at TSF had an entry that said the Atomics International Engineer had given a spontaneous demonstration on the hazards of working with NaK.”

Thanks, Mr. Paul, for sharing your memories.

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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.