California Dreamin’

Tales from the Nuclear Age:

 Copyright© by Charles Glassmire

_________________________________________________________________

Mar. 1, 2010

California Dreamin’

           We were flying to California to irradiate some Nuclear Rocket fuel in the General Electric Test Reactor. Dave was quite excited about California from his earlier trips there, and he talked about it continuously. As we walked across the tarmac in San Francisco the Sun was so brilliant I had to squint. Dave inhaled a deep breath and told me to “just smell the air here – it’s so different from Pittsburgh” – and it was. We had a motel in Hayward, which was down the coast halfway between San Francisco and Vallecitos, where the reactor site was located. But first Dave had promised to take us to one of the best restaurants in town. We took the rental car up and down San Francisco’s hills to Alfredo’s, and the meal was very special. The trip down the coast went quickly; the 101 freeways were six and eight lanes wide. Spectacular views of the ocean on our right.

          A phone call from the motel revealed the capsules had arrived safely at the Reactor. Since we were new customers, the irradiation would be done on the graveyard shift. That’s when they ran the “far out” stuff. So it was dark when we first drove to the site. I remember as we passed through the sugar loaf brown foothills approaching the test site that Dave wasn’t saying much. I began to feel a strange sense of detachment and loneliness – some kind of alienation and foreboding about what was to come. The lines of a song kept bothering me, something about

“Scooted out of ‘Frisco

over route 101,

got a hitch as far as San Hose.

Rode aboard a Greyhound

till I ran out of dough,

bid the bus goodbye at Monterey.”

           It was a dream of loneliness and loss in the California hills, and as I looked out the car window at the lighted up homes drifting by us like ships in some alien night sea, I fantasized floating out of the car and knocking on someone’s door. They would open and I would see a smiling mother and father. They would invite me in and welcome me as if I belonged, and the ship would sail away into the darkness, with me living there forever. But I didn’t.

          We arrived and met Al, our customer engineer. He gave us the two dollar tour. The reactor was housed within a giant steel dome three stories high, called the “Containment Vessel”. The idea was if anything went wrong, the vessel was air tight, and problems would be confined inside the vessel, thus no radiation would be released to the outside. This was not an unusual occurrence in test reactors. They were always testing new and experimental designs for fuel rods and other nuclear components, and every once in a great while something went a little wrong. There was never any danger of a nuclear explosion, but if things got too hot there could be a steam explosion, for instance, from fluids overheating. The GE Team had a safety committee which carefully reviewed every experimental design before it was cleared to be placed in the reactor. Our test plan and design had passed the committee nicely.

          Our irradiation was to use what was called the “Trail Cable” facility. This rig was located on the second floor of the containment vessel. It was actually a long tube which curved down two floors into the actual reactor core. The main reactor was a hugh thing which sat inside a swimming pool of water for cooling. When the reactor used up its Uranium fuel rods, they were off loaded and placed in a special section of the swimming pool to cool down and eliminate the highly active fission products as they died off. On the tour Al pointed out the cooling fuel rods underwater.

          I leaned over and peered into the water and saw an unearthly blue glow surrounding the fuel. It was called “Cerenkov radiation”. As the fuel emitted electrons into the water, they Cerenkov radiation from Advanced Test Reactortraveled faster than light velocity in the water. A photon (light) was ejected which couldn’t move fast enough to get “out of the way”. It was rather like a jet plane exceeding the speed of sound in air. The sound vibes from the wing can’t get away fast enough, so they pile up on the wing edge like a physical barrier. The glow was creepy. It actually passed through the fuel rods and made them translucent. You could  see through the rods as you moved your head from side to side.

          Nature had some kind of balance of energy in its design. The most active and dangerous fission products spat out lots of dangerous radiation as they decayed. But the very “hot” active ones decayed very quickly down to a reasonably safer level. The less dangerous isotopes put out less radiation, but often had very long “half lives” (the time for 50% of the atoms to decay into something else. After one half life you had half as many atoms, therefore half the amount of radioactivity emitted.) The isotopes decayed on a logarithmic scale, and we used a rule of thumb that after seven half lives, the amount of the isotope remaining was less than one percent. BUT the half life could be hundreds of years! Or only a few seconds.

          Our capsule was to be lowered into the trail cable tube to a precise position inside the reactor, so we knew exactly the neutron flux it was exposed to. There was a long corrugated metal hose attached to our capsule which delivered cooling water, so the capsule wouldn’t overheat and melt, or worse. The technicians brought out the capsule and hose and laid them out on the floor of the second level. Dave was busy measuring off distances on the corrugated hose and marking the lengths, so we could tell just how much had been inserted into the Trail Cable. It was after midnight, and he had taken off his suitcoat and laid it aside as he worked.

          We started up the Coolant Air Monitor, called the “CAM”. It was a radiation monitor device on a big four wheeled cart. It had a large diameter hose attached continually sucking on the air from the second floor. With a loud vacuum cleaner roar, the air was pushed through the radiation detector and checked for any radiation which might have bubbled up out of the reactor pool. This rarely happened but it was a reassuring safety device nevertheless.

          Finally Dave finished up the measurements, brushed off his hands and shouted to me that we were ready to insert the capsule into the reactor…

  (to be continued…)

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One Response to “California Dreamin’”

  1. Larry Hammond Says:

    Very interesting reading Chuck! Thanks for sharing.

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