How is it I have never heard of the Santa Susana nuclear accident?

I came across a report published yesterday--on a website called HealthyCal.org, which I know nothing about other than it is edited by Daniel Weintraub, who used to be a great opinion columnist for the Sacramento Bee--that says, "The 1959 partial nuclear meltdown at the Santa Susana Field Laboratory ranks as the third worst nuclear accident ever, releasing up to 100 times more radioactive iodine into the atmosphere than at Three Mile Island."

How is it I have never heard of the Santa Susana nuclear accident?

My next question was where is this place? According to Wikipedia, it's near Canoga Park, Simi Valley and Bell Canyon. (A friend of mine from college and his wife grew up in this very area. Their wedding reception was held at her parents' home in Bell Canyon.) Here is what Wikipedia says about Santa Susana:

The site is located approximately 7 miles northwest from the community of Canoga Park and approximately 30 miles northwest of Downtown Los Angeles. Sage Ranch Park is adjacent on part of the northern boundary and the community of Bell Canyon along the entire southern boundary.

Although the meltdown took place almost 53 years ago, it is still polluted with radiation:

More than half a century after a partial nuclear meltdown near Los Angeles, a federal study has found ground radiation levels nearly 1,000 times higher than agreed-upon standards for mandatory cleanup.

Up until 2010, the cleanup efforts at the site of the accident have failed.

In a survey of land around the former reactor site, the U.S. Environmental Protection agency found radioactive cesium, strontium, cobalt and plutonium at levels exceeding the cutoff requiring remediation, agency records show.

As often happens with these things, the standard for what is safe has changed and become stricter over the years:

The current agreement between NASA, DOE and the state Office of Toxic Substances Control seeks to return Santa Susana to a cesium background level of 0.0207 picocuries. A picocurie is one-trillionth of a curie — a standard measure of radioactivity. At one hotspot, the EPA found cesium 137 at 198 picocuries per gram. In other words, the intensity of cesium radiation at that particular location is almost 1,000 times the level that would trigger mandatory remediation.

One possible reason I had never heard of the Santa Susana accident is because it was kept secret for a long time:

The accident in the rugged Simi hills between Los Angeles and Ventura County on July 14, 1959 remained largely unknown for 20 years, until a group of UCLA students discovered and publicized records of the release. Further research revealed additional radioactivity releases as well as contamination by carcinogenic dioxins and heavy metals from other experiments at Santa Susana. That led to decades of agitation by environmental activists and a series of failed cleanup efforts before the 2010 agreement.

A current legal question is who is responsible to cleanup the site: the property owner, Boeing? Or the state of California?

Boeing Co. owns most of the 2,850-acre site, and, unlike NASA and DOE, has not signed on to the cleanup agreement with state regulators. Last April, a federal judge overturned a state law that would have made the company responsible to California officials for a cleanup. The state is appealing the ruling.

Boeing objects to the current plan, because it is much more stringent than a 2007 agreement:

Kamara Sams, a company spokeswoman, said Boeing remains committed to cleaning its property under a 2007 consent order that would forbid contamination above levels typical of a residential suburban neighborhood. She noted that that standard is more stringent than would be normally required for the site’s future use as open space.

Notwithstanding the Fukushima Daiichi nuclear disaster one year ago, I am sure that nuclear power is much safer today than it was in the 1950s or even the 1970s. Even though we--in the United States--have not really solved the problem of what to do with nuclear waste, I am generally in support of generating more of our electricity from new nuclear power plants. I don't think the takeaway from Santa Susana should be that nuclear is bad. I think the takeaway should be that we need regulations to prevent that sort of accident from happening; and if an accident occurs, we need to have a good plan in place ahead of time for how to minimize the damage.

From a carbon-effluent standpoint, nuclear power is an attractive option. However, a big obstacle for nuclear in the U.S. is how extremely expensive it is to build and operate a plant. Companies like PG&E and other power producers, given the choice between nuclear and natural gas, will pick gas every time. Based on what engineers at UC Davis have told me, it costs about half as much today to produce a megawatt of electricity using gas than it does using nuclear. Until that ratio changes, I don't expect anyone to propose a new nuclear power plant in California.