Photo of Joseph Mangano © Susan Burke Joseph Mangano directs the Radiation and Public Health Project (RPHP), an independent group of scientists and health professionals dedicated to research and education of health hazards from nuclear reactors and weapons. While at RPHP, he has written or co-written dozens of articles in medical/scientific journals. Mangano is the author of Low-Level Radiation and Immune System Damage: An Atomic Era Legacy (1998) and Radioactive Baby Teeth: The Cancer Link (2008). He played a prominent role in the Tooth Fairy Project, a study of Strontium-90 levels in 5,000 baby teeth, which remains the only study of radiation levels in bodies of Americans living near nuclear plants. Mangano holds a Masters degree in Public Health from the University of North Carolina and an MBA from Fordham University.

On a warm California morning - July 12, 1959 – just outside Los Angeles, workers at the experimental nuclear reactors at the Santa Susana Field Laboratory reported for duty. Those who worked on the Sodium Reactor Experiment, one of ten reactors at the lab, were eager to make the fourteenth in a series of tests of the futuristic machine. The experiment tried to cool uranium fuel in the reactor core with sodium rather than the standard method, which used water. Hopes were high that this design would revolutionize atomic power reactors in the US, and perhaps around the world.

There had been problems with the first thirteen tests over the past two years. In the most recent one, there had been an explosion. The inexperienced workers tried to find its cause, but were unsuccessful. In retrospect, leaks had probably limited the ability to keep the sodium cool – a crucial aspect of running the reactor safely. But instead of taking the prudent path of stopping or postponing the test series, Test 14 was placed right on schedule, with no delays.

Almost immediately after work began, something went badly wrong. The sodium was not cooling the reactor core, which heated up to levels never seen before at Santa Susana – or perhaps in the US. Inside the core were long rods, containing uranium atoms that were split to power the reactor, along with the dozens of dangerous radioactive chemicals formed as waste products when uranium atoms are split. The long rods began to melt, and a large volume of radioactive gas built up in the reactor room. Instead of shutting down the reactor and investigating the cause, technicians added additional rods designed to control the process, but these only made the situation worse.

The next two weeks were a series of re-starts and more melting down, similar to repeatedly banging one's head against a brick wall. Why didn't managers shutdown the Sodium Reactor Experiment? The answer was one common to the US atomic power program; adherence to a mentality of "the show must go on" in spite of any dangers. Every day, radioactive gases from holding tanks in the reactor building were released into the air – often at night, a highly toxic job given to workers on the "graveyard shift". Finally, two weeks to the day after the run started, the reactor was finally shut down. The amount of radiation released into the environment was never accurately measured – in fact the entire meltdown was kept secret from the public for the next two decades. Sodium cooled reactors failed; of the 439 reactors operating worldwide today, only two are sodium cooled (none in the US). But the damage had been done, and today the Santa Susana site sits amidst a large mess of toxic waste.

Photo of Joseph Mangano © Susan Burke Joseph Mangano directs the Radiation and Public Health Project (RPHP), an independent group of scientists and health professionals dedicated to research and education of health hazards from nuclear reactors and weapons. While at RPHP, he has written or co-written dozens of articles in medical/scientific journals. Mangano is the author of Low-Level Radiation and Immune System Damage: An Atomic Era Legacy (1998) and Radioactive Baby Teeth: The Cancer Link (2008). He played a prominent role in the Tooth Fairy Project, a study of Strontium-90 levels in 5,000 baby teeth, which remains the only study of radiation levels in bodies of Americans living near nuclear plants. Mangano holds a Masters degree in Public Health from the University of North Carolina and an MBA from Fordham University.

On a warm California morning - July 12, 1959 – just outside Los Angeles, workers at the experimental nuclear reactors at the Santa Susana Field Laboratory reported for duty. Those who worked on the Sodium Reactor Experiment, one of ten reactors at the lab, were eager to make the fourteenth in a series of tests of the futuristic machine. The experiment tried to cool uranium fuel in the reactor core with sodium rather than the standard method, which used water. Hopes were high that this design would revolutionize atomic power reactors in the US, and perhaps around the world.

There had been problems with the first thirteen tests over the past two years. In the most recent one, there had been an explosion. The inexperienced workers tried to find its cause, but were unsuccessful. In retrospect, leaks had probably limited the ability to keep the sodium cool – a crucial aspect of running the reactor safely. But instead of taking the prudent path of stopping or postponing the test series, Test 14 was placed right on schedule, with no delays.

Almost immediately after work began, something went badly wrong. The sodium was not cooling the reactor core, which heated up to levels never seen before at Santa Susana – or perhaps in the US. Inside the core were long rods, containing uranium atoms that were split to power the reactor, along with the dozens of dangerous radioactive chemicals formed as waste products when uranium atoms are split. The long rods began to melt, and a large volume of radioactive gas built up in the reactor room. Instead of shutting down the reactor and investigating the cause, technicians added additional rods designed to control the process, but these only made the situation worse.

The next two weeks were a series of re-starts and more melting down, similar to repeatedly banging one's head against a brick wall. Why didn't managers shutdown the Sodium Reactor Experiment? The answer was one common to the US atomic power program; adherence to a mentality of "the show must go on" in spite of any dangers. Every day, radioactive gases from holding tanks in the reactor building were released into the air – often at night, a highly toxic job given to workers on the "graveyard shift". Finally, two weeks to the day after the run started, the reactor was finally shut down. The amount of radiation released into the environment was never accurately measured – in fact the entire meltdown was kept secret from the public for the next two decades. Sodium cooled reactors failed; of the 439 reactors operating worldwide today, only two are sodium cooled (none in the US). But the damage had been done, and today the Santa Susana site sits amidst a large mess of toxic waste.