Chemistry and The Scourge of Plutonium Pollution

By

Home / Chemistry and The Scourge of Plutonium Pollution
U_Plant_large

Original Plutonium processing site for the Manhattan project, Hanford, Washington. Image by U.S. Department of Energy

The atomic bomb known as “Fat Man” was dropped to help end WW II on August 9, 1945; it was a plutonium device. Up until 1945, only a select few knew of  plutonium or its potential for harm. However, the atomic scientists of 1940s-1950s were hopeful for a beneficial use to this radioactive element.

Productive, peacetime uses for Plutonium are presently rare, but it has found use as a power source for space-faring probes (e.g. Voyager spacecraft and for the New Horizon’s mission).

Fukushima Follow-up

The mentioning of a radioactive water plume containing plutonium conjures nightmares for many individuals. In the aftermath of 2011 Japan earthquake, people in different parts of the world feared for themselves and the Japanese people, as well.

The concerns of radioactive plutonium are well-founded.  However, the truth, at the present moment, is that no single individual has died from radioactive exposure from the 2011 earthquake. (All deaths occurred as a result of the earthquake and subsequent tsunami.) Even if no one has perished or been significantly ill from the Plutonium or other fallout, Plutonium fallout bears mentioning since its status is still in question. 

The Chemistry of Plutonium

Given the radioactive nature of Plutonium, traditional chemical methods are poorly understood. Much of what is researched on Plutonium chemistry is its resemblance to Iron chemistry: In one reactive state, Plutonium forms bonds with organic molecules in  similar patterns to Iron.

The similarity appears puzzling until the recollection of how acute metal poisoning is medically addressed (i.e.; Iron, Mercury, Chromium, or Tin). The metals atoms form a loose association with organic molecules-known as complexes.

The metals can be ‘drawn out of the body’ with organic chemical agents that form ‘complexes with the metals.’ Complexation, although difficult to conceptualize, may be thought of as capturing or sequestering the toxic metals away from the sensitive body tissue.

The metallic nature of Plutonium is different than it is for Iron or Cobalt. Plutonium is a denser material than Iron and is less chemically reactive than Iron or Cobalt, as well.

Complexations of Calcium and Cobalt are illustrated. Copyright image by John A Jaksich, all rights reserved.

Complexations of Calcium and Cobalt are illustrated. Plutonium complexation is similar but poorly understood. Copyright image by John A Jaksich, all rights reserved.

Where Is the Plutonium at Fukushima?

Initial estimates of released, radioactive plutonium are less than one gram. [It should be noted that an ‘exclusion zone’ exists in the Fukushima Prefecture in Japan-no one is presently allowed to stay for extended periods of time in the disaster zone.]

The final words on the subject are still being written (and researched), however, what we know for sure is the accident released Plutonium over 80-to-90-mile radius from the explosion site.

The most reliable descriptions of the fallout describe the radioactive substances as a black solid on the roadside. (Pure elemental Plutonium reveals itself to be a dark yellow solid.)

The Plutonium fallout, once on the ground, attracted organic matter-it essentially clumped with dirt and litter. Moreover, Plutonium from the nuclear reactor is chemically reactive, once exposed to oxygen and other weather elements-it undergoes a ‘reaction’ (changing its appearance).

Plutonium, purportedly, accumulated by riverbeds and streams through weathering of the landscape. (Presently, clean up efforts have reclaimed parts of the exclusion zone.)

What of Plutonium in the Pacific Ocean?

Most of the prevailing winds during the accidents blew in a Westward direction (towards the Japanese mainland), but what about Plutonium in the Pacific Ocean?

There is more than one source of Plutonium in the Pacific Ocean. When scientists needed to estimate the total amount of Fukushima Plutonium in the Pacific, they had to account for the old testing sites otherwise known as ‘the atomic proving grounds.’ The prevailing ocean jet stream circulates Plutonium from the test sites into the sea of Japan; Plutonium was measured in the waters off the Japanese coast as late as three years prior to the Fukushima accident

The Plutonium from the Fukushima accident is found in the ocean sediment near the reactor and in a reacted state in the ocean water.

Recent studies of water-plutonium chemistry reveal the Plutonium fallout to aggregate with the microscopic-sized matter in the ocean. Thus, organic and inorganic matter in the ocean such as, fish remains and minerals such as quartz, manganese and iron attract the Plutonium fallout. Much like the complexation reactions mentioned above-the Plutonium tends to attract the flotsam of the Pacific.

Can We Remove the Plutonium from the Pacific Ocean?

In the short response, Plutonium appears to be a permanent fixture of the Pacific. However, the long answer appears hopeful. It would appear to hinge on several factors of present-day research. The dissolution of Plutonium in the Pacific is generally regarded as poor-but it is circulating throughout the Eastern Pacific Ocean, nonetheless. What has not readily dissolved in the ocean is in a dynamic state of circulation between the flotsam and the ocean bottom.

Research is still conducted in the hopes of improving upon the complexation of Plutonium with organic molecules. Seventy years ago, scientists used EDTA to sequester Plutonium. Present efforts use similar-and but larger molecules.

This author believes that ‘a synthetic flotsam  (0r a molecular sieve)’ could be developed to trap Plutonium from hotspots-or areas of known higher concentrations of Plutonium. Such areas consist of the coast of Japan or the atomic proving grounds of WW II. In much the same way that a sieve can trap the desired product but allow the water to percolate away, perhaps we can re-claim a clean Pacific Ocean.

Plutonium, Chemistry, And Science

Often, researchers pin their hopes on developing new and better ways of living – and many times, they succeed. No matter how bleak a situation might appear, we can not give up – science can provide answers.

Leave a Comment