The story of Humboldt Bay Nuclear Plant is an expose of PG&E and an expose of nuclear regulation. It’s happening now. Its dangers and warnings are critical for the public to heed.

In 1970, a power outage caused the Humboldt Bay Nuclear Power Plant to malfunction. Using historic sources, we investigate whether this resulted in a leak of radioactive gases.

Unofficial transcript based on auto-transcript:

My name is Scott Rainsford .I was born in Iowa. I was a marine science technician in the United States Coast Guard initially four years active duty, followed by another 14 roughly years of Coast Guard Reserve when I came up here. As a marine science technician, my commanding officer in the Coast Guard Reserve sent me to the PG&E nuclear power plant in the year 1978 to see if I could update their contingency plan.

I went to the plant, I read their contingency plan, and after i had thoroughly read it i asked if they ever had a chance to use it. They replied, Well. as a matter of fact, yes we have.”

They brought out this report marked “confidential.”

When a nuclear plant is operating, there is a person in charge called a nuclear operator and he keeps a log of every important fact or issue that happens during his watch. There’s a time annotation and then what happened.

The report described an accident that happened on July 17, 1970. It just so happened that a man named Shiffer was there, and he was one of PG&E’s best and brightest. He was a senior nuclear operator. So seeing this crisis developed, he took command of the reactor. So the log that i was reading was his operational log.

This report described the following:

A maintenance crew from PG&E went to a local substation at an area called Mitchell Height, and they were going to do some maintenance on a high tension line. They believed that this high tension line was dead. Because of that, the maintenance crew opened an air circuit breaker. The result was a fireball which melted and damaged the whole circuit. That 60 000 volts was supplying outside power to PG&E’s unit number three.

The nuclear power plant when they lose outside power, down goes the feed water pumps that feed coolant water into the reactor. So we have an issue of overheating the core.

The next in line during this initial start of the emergency was a propane generator. Problem with this propane generator was that it did not provide enough power to supply the feed water pumps which would keep the reactor cool, and it also did not supply all the power necessary to run the instrumentation that the nuclear control operator needed to understand what was happening to the reactor so he had no idea how much coolant remained. So now, the nuclear operator is operating blind.

There were three units. The first two units were petroleum-based. The third unit was the only nuclear plant. When the nuclear plant is running, one of the other two units must be in operation and that is so that if the nuclear unit lost outside power, the other operating unit could supply emergency outside power to the nuclear unit. It failed because several months before, another maintenance crew had disconnected a cable in the switch yard and therefore, could not complete the circuit. The second major part of the fail-safe system failed. That piece of equipment was called an emergency condenser. What that is a compartment partially filled with water that functions similar to a car radiator. A valve that automatically is supposed to open from the reactor taking this out of specification pressure in the form of steam. It runs through a series of baffles in this emergency condenser which is partially filled with water. The steam is cooled, condensed back into water, and put back into the reactor core to keep it cool. The emergency condenser failed, because a valve would not open.

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