First contact made with melted nuclear fuel at Fukushima plant • Hacker News Board

Re: First contact made with melted nuclear fuel at Fukushima plant

#181

Post by pvaldes » Sat, Feb 16, 2019, 10:15 AM UTC

tarre wrote: post #170

adrianN wrote: post #162

Earlier quoted context omitted.

Adding another factor of 100 with something as cheap as sand still seems worthwhile.

There are reasons, why not to do that: 1) DF doesn't add up like that at low concentrations. Then it comes down to selectivity of the material. Sodium and cesium have similar chemical characteristics, but CsTreat is very efficient in selecting Cs over Na. 2) Material you are using as filter becomes radioactive waste. You want to keep the volume at minimum. 3) With CsTreat you already reach radioactive Cs levels below…

Honest question. Is is being CsTreated since eight years, why we do have radioactive Caesium still accumulating in the coast?

> 2) Material you are using as filter becomes radioactive waste. You want to keep the volume at minimum.

This is very reasonable, but storing sand for 50 years somewhere is technically feasible and maybe even cheaper than storing water. You can put the sand in concrete and obtain a solid block. Then put the package in some kind of coating and bury it in a safe vault. Water instead has the bad habit to leak, run away, and enter in the life chain when bad weather, monsoon or accidents happen. A huge concrete block is also less vulnerable to terrorism than a water tank. Is not so easy to steal a jar of it, for example. Even if you could make a hole in the coating, the product will not just flow out.

Re: First contact made with melted nuclear fuel at Fukushima plant

#182

Post by pvaldes » Sat, Feb 16, 2019, 10:25 AM UTC

Haga wrote: post #176

pvaldes wrote: post #138

Earlier quoted context omitted.

But sand is not normally made of eroded granite, or it does not contains only granite. A lot of sand is made of shells or coral. Most beaches should have much lower levels of radioactivity.

Behold the prolonger of discussion and destroyer of easy decideability : It deepends

What I mean is that we can't just take the most radioactive beaches in the world and assume that this is the normal level in beaches so "is not so bad". In the real life, beaches aren't made (only) of granite dust. Most material is silicon, carbon and calcium.

And we should remember that unless x-chest rays, thousands of people lay practically naked in the same beach and favourite spots for entire weeks, ten hours a day. Being exposed to the UV rays of the sun also, that is another important source of cancer. In this cases, even relatively low dosis could be of concern.

People at the beach eats a lot of local sea foods also.

Re: First contact made with melted nuclear fuel at Fukushima plant

#183

Post by chillydawg » Sat, Feb 16, 2019, 10:51 AM UTC

kortilla wrote: post #174

afterburner wrote: post #141

Earlier quoted context omitted.

Building new reactors costs a massive amount of money, more than pro-nuclear advocates realize or are willing to admit. Shutting down reactors doesn't save much money; they've already been built. They also weren't built when renewable energy was developed into the very cost-effective solution it is today. The worst thing about building new reactors using existing technology (which would really no better than the exis…

>Building new reactors costs a massive amount of money, more than pro-nuclear advocates realize or are willing to admit. Those costs are entirely political. Fear mongers have made it extremely difficult to get a nuclear project to completion (see the whole NRC approval process). Solar panels would be super expensive as well if each one had to go through a giant 30 year planning process that NIMBYs could easily disrup…

Well it's certainly not feasible in the US with the current government in power.

Re: First contact made with melted nuclear fuel at Fukushima plant

#184

Post by vidarh » Sat, Feb 16, 2019, 10:52 AM UTC

mempko wrote: post #169

vidarh wrote: post #166

Earlier quoted context omitted.

The reaction to Chernobyl was excessive. What we've learned since is that while a lot of rapid response was needed at the immediate site, at least a portion of the rapid evacuation likely did more harm than good. Large parts of the exclusion zone remained livable (and the Chernobyl plant itself remained operational for many years afterwards - the danger was low enough that several of the reactors were re-started). We…

This is an interesting perspective. It's probably unknown if it's too much or too little without some serious scientific investigation. What do you base your opinion on?

For starters there's extensive data on effects of staying in large areas of the outer exclusion zone, because a lot of people (a small proportion of the population, though) stayed or went back. The government eventually gave up on keeping people out.

Secondly, there is the experience of continuing to operate the other reactors. It took 3 years before work on reactor 5 and 6 (which were unfinished) was halted. Operations at reactor 2 continued until a fire in 1991. Reactor 1 remained in operation until 1996, and reactor 3 was finally decommissioned in 2000. While workers were subject to stringent controls, and on/off schedules intended to reduce their exposure, people were nevertheless working in some of the most radioactive areas of the exclusion zone for many years, with very limited indication of lasting problems.

Thirdly, there is the economic impact on the Soviet Union in general, and Belarus overall, both unavoidable costs of the cleanup, but also very much avoidable costs of large-scale reduction in economic activity in a large area. There is a lot of data on the subsequent effects of the economic upheaval that followed the breakdown of the Soviet Union that shows the effects of economic upheaval on e.g. life expectancy. Applying the same to the upheaval caused by evacuation of areas that were quickly known to be within safe radiation levels implies substantial harm.

In general any evacuation causes substantial harm, because of e.g. increased mortality when moving hospital patients or other vulnerable groups; increased traffic accidents etc. Just doing more stuff quickly causes harm.

Re: First contact made with melted nuclear fuel at Fukushima plant

#185

Post by pvaldes » Sat, Feb 16, 2019, 11:14 AM UTC

acidburnNSA wrote: post #113

Intermernet wrote: post #109

Earlier quoted context omitted.

When were the majority of reactors operating today designed? Serious question. I actually want to know.

1960s and 1970s mostly. Chernobyl was designed earlier. Fukushima was a super early design. The real flaw there was they put the backup generator fuel supply in the basement in a flood zone. The reactor was designed for the US midwest, with tornados in mind as the biggest threat. Moving to Japan, they should have put at least some of the backup fuel above ground level and it would have been fine.

The flaws in an earlier design can't be a justification for absence of upgrade. Since 1960 we had build thousands of structures higher than 150m. Skyscrapers are not exactly a novely. We have the tools and the knowledge.

They had 51 years, 51! to raise a damned wall 20 m. Had all the new information, improved models, latest computers and warnings... and they didn't do anything. Neither Tesco, nor the Japanese government were able to see it coming. Their lack of vision is really infuriating.

Re: First contact made with melted nuclear fuel at Fukushima plant

#186

Post by teamonkey » Sat, Feb 16, 2019, 11:48 AM UTC

sigstoat wrote: post #40

eecc wrote: post #28

Earlier quoted context omitted.

LED lights? Highly isolated apartment buildings? Revised urban planning to accommodate a post-commuting work-life? Other energy saving technology? In EU we have a comfortable living off consumption levels that in the US would qualify as church mices' (still not enough to prevent collapse though: https://web.archive.org/web/20140913032823/http://graduatein... )

> LED lights? you need to be addressing the larger chunks of these pie charts: https://www.epa.gov/energy/electricity-customers

Switching to LED lights (and reducing usage) is one example of low-hanging fruit that is easily achievable without affecting lifestyle much. The fat needs to be trimmed in all areas.

Re: First contact made with melted nuclear fuel at Fukushima plant

#187

Post by mikekchar » Sat, Feb 16, 2019, 12:24 PM UTC

hrktb wrote: post #180

jessriedel wrote: post #129

Earlier quoted context omitted.

From the executive summary (for others): > ...its assessment of the exposures and effects due to the nuclear accident after the 2011 great east Japan earthquake and tsunami... It had concluded in that report that, in general, doses were low and that therefore associated risks were also expected to be low. A discernible increase in cancer incidence in the adult population of Fukushima Prefecture that could be attribut…

I’m a bit frustrated by some of these arguments. In particular there is all this “expected” part about low level of radiation that _should_ lead to low effects. That all fine, until we get the numbers of actual cases, which are higher than expected. But then we have something looking like backpedaling, a lot of “yeah it’s higher, but it’s not what you think. Because it should be low”, wich I’d take as a partly circul…

That paper has some wording that is hard to understand, so I think this might be what's causing you trouble. The quote you make from the paper is not the only reason. They give 5 reasons.

- The exposure rates are significantly lower that Chernobyl (earlier in the paper they explain that in previous studies there is a correlation between exposure and cancer rates -- because the thyroid problem rates here are high while exposure rates were low, it is possible that the high rates are caused by something else)

- There is no apparent difference in rates corresponding to proximity to the disaster. Similar to the above, our models would predict that as you get closer to the disaster thyroid problem rates would increase. Because this is not happening, it seems likely that the high rate is due to something else.

- The high rate of thyroid problems was detected mostly in older, not younger children. If the thyroid problems were caused by exposure to radiation, our models predict that younger children would be more susceptible. Because we have the opposite, it is likely that the cause is something else (this, to me, seems one of the more convincing arguments). However, they note that it may just be a case that by chance the younger children may not have developed problems yet and so further study is required.

- Thyroid problem rates in other prefectures are also high (and, in fact higher than in Fukushima). Again earlier in the paper, they discuss this in much more detail. It was interesting to me that even as far south as Yamanashi, there were very high rates.

- The gene mutation and rearrangement rates are different than that of Chernobyl.

From those pieces of evidence, they conclude that the high rates of thyroid problems are likely due to some other cause (many possibilities of which they describe in the paper).

Like I said, I found the wording in this paper to be difficult to understand. It appears to have been written by non-native English speakers (mostly Japanese), so that's probably why. If you read it again, hopefully it will make more sense.

Re: First contact made with melted nuclear fuel at Fukushima plant

#188

Post by [deleted] » Sat, Feb 16, 2019, 12:38 PM UTC

avar wrote: post #135

toomuchtodo wrote: post #133

Earlier quoted context omitted.

>Look at how fast the Chinese are building them, or how fast e.g. the French or the US were at building them in the 60s and 70s. "The country [China] has the capacity to build 10 to 12 nuclear reactors a year. But though reactors begun several years ago are still coming online, the industry has not broken ground on a new plant in China since late 2016, according to a recent World Nuclear Industry Status Report. Offic…

I made no claims about overall cost, but pointed out that it taking anywhere near 20 years to build a nuclear power plant is clearly off by an order of 4x at the very least.

[deleted]

Re: First contact made with melted nuclear fuel at Fukushima plant

#189

Post by avar » Sat, Feb 16, 2019, 12:39 PM UTC

toomuchtodo wrote: post #133

avar wrote: post #123

Earlier quoted context omitted.

Nuclear power plants take at most 5 years to build from the time we break ground until the reactor's hooked up to the grid. Look at how fast the Chinese are building them, or how fast e.g. the French or the US were at building them in the 60s and 70s. That it takes so long now in the west is because we're not building enough of them, thus losing the advantage of experienced workforces and inability to leverage mass-m…

>Look at how fast the Chinese are building them, or how fast e.g. the French or the US were at building them in the 60s and 70s. "The country [China] has the capacity to build 10 to 12 nuclear reactors a year. But though reactors begun several years ago are still coming online, the industry has not broken ground on a new plant in China since late 2016, according to a recent World Nuclear Industry Status Report. Offic…

In reply to your edit:

> I’d prefer nuclear reactors not be built in the developed world to Chinese standards.

It's a bit more ambiguous today with solar etc. being much cheaper, but this sort of sentiment has been common over the years, and has doomed millions to an early death due to coal emissions.

Obviously it's nobody's serious policy suggestion that we literally dig up a 60s reactor design and mass-manufacture it as-is today.

The point is that we've been getting nuclear policy so wrong since then that we'd have been better today off in terms of the trolley problem of harm reduction if we did that, v.s. building the coal plants we've been building instead.

Any concerns about the safety of specific power generation methods that don't take into account what the realistic alternatives just amount to intellectual masturbation.

It would be like being so concerned about the safety of Ford (nuclear) v.s. Tesla (solar), that you've decided to instead ride a moped (coal) at highway speeds for decades out of some sort of misplaced decision paralysis, because you didn't yet have money for a Tesla.

Re: First contact made with melted nuclear fuel at Fukushima plant

#190

Post by varjag » Sat, Feb 16, 2019, 12:41 PM UTC

roenxi wrote: post #124

varjag wrote: post #80

Earlier quoted context omitted.

I've met a dying Chernobyl first responder on a commuter train in Belarus, back in early 1990s. These people never made it to WHO statistic as their deaths protracted over many years can not be directly attributed to the accident. As pro nuclear crowd would be happy to tell you, only couple dozen firemen died on the first day and that was it, making nuclear meltdowns almost benign incidents.

It is a pretty hard-hearted thing to say, but if the WHO doesn't think there is enough evidence to count his death in the Chernobyl statistics, what evidence does he have they are wrong? I mean, it isn't unprecedented for crippling damage to not surface for a long time (eg, asbestos/mesothelioma), but on the other hand cancer can strike at any age [0] and people struggle to attribute things to chance if they have a p…

Most of the studies among Chernobyl liquidators were based on monitoring the cohorts between 1994 to 2004. Very little was done form 1986 to 1991 at all.