I’ve been poking around on the web and here’s what I’ve found.  Here’s a pretty good map and overview of the Port Chicago area.  Turns out you CAN go right to the actual Port Chicago blast site by appointment.  Once you’re there, you want to look for and carry out just one single sample of trinitite, the fused sand that’s formed at a ground zero.  According to the popup window that comes up at that last link about “fake trinitite”, the real stuff always has a gamma-ray spike at around 600 keV.  You see that, you’ve got Proof.  Since you probably aren’t going to be able to lug a gamma ray spectrometer on site, your RM-80 will have to do.  It appears quite capable of detecting Cs-137 radiation from a ground zero blast.  

Hey, let us know what the Park Service says when you try to set up your trip, and what your RM-80 says when you get there.  And take plenty of photos!  Good luck!

I’m not sure how to test that. But yes, we have to consider every possibility.

For anything that can be tested with more measurements in the area, all I need is a suggestion of where to look and I can go collect data from there.

But for something like what rickyjames suggests, I think we have to leave that to the media to prove or disprove for sure. I just can’t get access to anything inside the military base. Although as I try to wrap my brain around the scale of a 2-mile wide plume that disperses within 10 miles to the NE, I think that indicates a large release of material originating nearby.

We were already able to check that the “broken arrow” accident at Travis AFB in Aug 1950 (B-29 carrying an atomic bomb crashed and burned) did not produce a plume that could cause this. And it’s north of where this apparent plume disperses.

There’s almost certainly going to be a trip to the blast site today by the Park Sevice, on a Saturday on the 50th Anniversary.  Any West Coast earlybirds reading this, you could be a hero by sundown starting with a let-me-tag-along phone call over breakfast.  Heck, even if you’ve got to be pre-cleared for access, you can make friends with the Park Service Ranger that goes there routinely, hear what they’ve got to say, and loan them the RM-80 for a day…

FYI, based on this map of the Trinity site in New Mexico, if there WAS an atomic blast at Port Chicago, the background radiation level there would almost certainly still be elevated enough for a RM-80 to detect quite easily…

.
…I am curious about:

…..What direction was the prevailing wind the day (and time) of the explosion?

…..Is there debris still in the water — perhaps part of the hull or cargo?

…..Can somebody take some pictures of the Port Chicago site, Grizzly Island, and the surrounding area to post? (well, unless the background radiation will ruin the film <smirk>)

…..Does the “friendly” Park Service Ranger carry a dosimeter?

This is a very interesting and thought provoking first person article, well worthy of SciScoop’s front page.

jon

That’s a big “if”. Yeah, if the urban legend is true, then there should be some residual radiation which the RM-80 can detect.

But don’t forget that Concord NWS is an active military base. I’m not going to try to sneak a pack of equipment onto the base or take any “samples”. The military is serious about security with good reason, and should be taken seriously. I’d be willing to visit the NPS Port Chicago memorial site with the RM-80 if they know what the equipment is that I have with me, and I’m confident that I’m not at any risk of getting arrested.

This is rather surreal for me. I drove out on Thursday sort of hoping to say, “See, there’s nothing here.” But that wasn’t what I found. I’m still a bit spooked by the discovery. I got my RM-80 to help stay away from downwind fallout areas when my friends and I are travelling in Nevada and Utah. I wasn’t planning to seek these areas out.

It’s just as well not to go today. Let the remaining survivors and their family have the 60th anniversary ceremony without any disturbance.

July 17 might have been a bad day for radiation readings. The Sun has been blasting X-rays this week. Check if your radiation detector is sensitive to that … and just what readings has it been giving you all week?

Yeah, upon reflection I agree that rolling in there on the anniversary probably wouldn’t have been too cool.  

I’ve done some more research (in part based on blog responses you’ve posted on your website) and I must say I’m rather surprised how compact the whole Port Chcago area is.  Here’s the Terraserver aerial shots of the Port Chicago area (note that with the zoom, you can easily see the railroad tracks and individual cars) and judging from Mapquest obviously you can get within a mile, two at the most, of the Port Chicago blast site on all four N,S,E,W directions while staying on public land.  If there had been a nuke blast, I just can’t see how the public wouldn’t have noticed the radiation by now.  Plus I agree with what one blog guy said, the released photos sure don’t look like an atomic bomb level of damage…  

So I dunno anymore.  Your readings ARE weird; there’s a mystery there, but as to just what, I just don’t know.  Would sure be interesting to use Mapquest, stay on public roads, and drive around Port Chicago with your setup as much as you can without getting on the NWC itself (hint, hint)…  

For the record, one of the pages I came across said that NWC Concord / Port Chicago used to be a storage site for U.S. Navy W-80 nuclear-tipped Tomahawk cruise missiles, but wasn’t anymore, they supposedly got pulled out a few years ago.  Maybe they’re not so justifiably paranoid about security there anymore, which is why they let the Park Service run tours now…

The data were collected on Juy 11 and 15, not 17. X-rays are so efficiently absorbed by the atmosphere that none make it down here. That’s why all x-ray telescopes are in space. However, other types of radiation from space should be considered.

The proton flux (measured from GEO), was actually really low and quite variable. I looked at neutron fluxes (neutrons are not ionizing, but are a reasonable proxy for ionizing radiation) from ground-based neutron monitors such as at Oulu, Finland . You can order your own plots. Try using the smallest time interval possible, one minute, and note that neutron fluxes can vary within a range of ~10% in the span of a minute. One would expect even greater variation at time intervals of roughly a second such as was used in the Port Chicago study (a guess, just judging from the data log), though it’s likely that fluxes of ionizing radiation are less variable than neutrons. Also depends greatly on the equipment used.

To put to rest questions of background radiation variability, a relatively simple correction to the method could be made. Drive the same routes repeatedly, so that there is more than one datum for each geographic location, separated in time. This would allow sophisticated statitistical analysis. Without it the results are suspect. Also, the study seems to have been done in a hurry to meet the July 17 deadline. The author notes problems with colors in the second graph, but did not attempt to fix it before presenting results. One good thing they did was to get data at night to reduce solar radiation.

Can you supply the names of ships that participated in Operation Crossroads and then were at Port Chicago? So far, I have only be able to verify that the submarines USS Dentuda (SS-335) and USS Parche (SS-384) were involved in Crossroads and then spent significant time at Bay area ports. Neither were at Port Chicago. Parche was at Mare Island, and Dentuda was at Hunter’s Point. Dentuda was broken up there. Parche was not. Any names, dates, and ultimate dispositions would be of great interest.

You would not likely find trinitite at the site as the explosion occured under water, however, a nice soil sample may have some isotopes that could be detected and a piece of the original metal may also have some radioactive activation products.

Keep in mind Trinity was a plutonium bomb detonated 100 feet or so above the ground, whereas the bomb at PC would have been uranium and detonated inside a metal ship under at least ten feet of water. Results from pacific testing showed very little fallout from underwater blasts as compared to airbursts.

There were several ships that were taken to PC for cleaning, but they were also decontaminated at Bikini, if there was any fission products that came off ships at PC they would only likely be found in the immediate vicinity and not across the bay.

The crater was completely dredged out by the navy after the explosion, but not before scientists from Los Alamos’ Manhattan Project thoroughly studies the damage pattern, the crater, and even the tidal wave that was produced by the explosion. These documents are all available from Los Alamos.

I would not be too excited by a 3 to 5 micro-r difference, that is really not too significant, but it is likely all that would be expected if there really is a plume, and if the wind direction that night matches the plume. That kind of difference could even be accounted for being too close to the road, or the soils used in the levee, or the geology of the area, etc. Soil samples are the answer and should be analyzed for fission product isotopes.

Could you be a bit more specific about ‘which’ several ships made their way to Port Chicago? Let’s remember that Port Chicago was essentially an ammo depot. The ships that were destroyed and damaged in the explosion were cargo ships, specifically Liberty-type ships. This would have been the most prevalent type of ship at Port Chicago. The sub pens were at Mare Island. And other combat types were supported via Alameda. Also, I cannot find any evidence of ’secondary’ or ‘tertiary’ decontamination of ships at any of the Bay area facilities. For instance, http://www.history.navy.mil/danfs/p2/parche-i.htm points out that Parche (USS-384) was decontaminated at Bikini and then proceeded to Mare Island. No mention is made of a second decon procedure.
Also, take a look at: http://www.aracnet.com/~pdxavets/crossroa.htm. Several of the veterans described the harrowing decontamination procedures that were used at Bikini–lye, seawater, & buckets–but none describe these procedures as taking place at Port Chicago, Mare Island, etc.
I do not doubt your claims, I would just like an opportunity to view the original source materials. Thanks…

Well i did say they were decontaminated at sea primarily, although i saw a site from one of the navy bases near san francisco where they said the area was used for decontamination. I still kind of doubt that much actual decon would have been done there as the ships would have had to be cleared and screened to be allowed to come in through the bay anyway. It did say LCI-549 was towed to PC but it had already been cleared. I dont really think it is all that relevant anyway IF there was significant radiation found across the bay it really wouldnt be from ship decon anyway.

The background radiation observations page has been updated.
I fixed the image-generation software so that the colors are displayed correctly. And it uses a more intuitive choice of colors now. (And an improvement that helps me too – instead of taking an hour averaging too many data points, the new algorithm takes only a few seconds to run.)

Also, an update on the July 11 drive. There was a 14 uR/hr data point on Shiloh Rd which I missed. (It’s easy to miss one point when you’re sifting through hours of data taken at 1-second intervals.) The image has been updated to point out where it was.

I’ve been back to Grizzly Island two more times to collect more data. That should be posted either over the weekend or early next week. Highlights of what I learned…

• If you drive too fast, you won’t see the small “warm spots” as more area around it gets included in the counts per minute.
• When driving slower, one reading on Grizzly Island went up to 20 uR/hr, which is now the highest reading I’ve recorded in that area.

I was wondering if you stopped the car, and took a measurement. I really know nothing about radiation, but it seemed to me with my ignorance somewhat logical that it would make a difference. But I didn’t want to point out my ignorance. You know … that whole don’t open your mouth, lest you remove all doubt thing.

The system records a reading from the geiger counter every time it gets a location from the GPS. Nominally, that’s once per second.

So whether I’m stopped or moving, it’s recording. Yes, that means there is more data that can be recorded by stopping in every location. Maybe there will be time for that some day. But for now we’re still scoping out the whole situation. This mobile collection mode is useful for catching anything out of the ordinary over a wide area, just by driving there.

What speeds get reliable readings? It looks like the slower the better. I did one run through Grizzly Island at 35mph and it missed almost everything. At 20 mph it catches things pretty well. But the first drive there was at times as slow as 10 mph and got the most data. So, yeah, eventually that will have to be recorded with a lot more stops. I think I’d prefer to recruit some helpers with similar equipment before trying to do that exhaustive a survey, except maybe in small sample areas.

For areas like that, it might be useful to experiment with turning down the readings from a 60-second moving average down to 30 or even 20 seconds. It wouldn’t be as well-averaged data. But it may help catch things that need a closer look.

But for now I’d put a higher priority on making another run further to the northeast. I did Hwy 12, Hwy 113 and Shiloh Rd at highway speeds. So far, Shiloh Rd had one 14 uR/hr reading and consistently elevated readings even at 65 mph. Since it’s in the area which appears to be further downwind, it’ll also need another pass at a slower speed to take a closer look. As long as I keep finding discernable elevated readings, I’ll have to keep checking around them to find the overall shape of the elevated background radiation area.

So far unproven, it looks like it elongates and fades in the direction that the winds usually go in the area. That’s what formed the basis of the hypothesis that this could be a plume.