OPG unclear about nature of radioactive waste: environmental

[Oscar]

OPG unclear about nature of radioactive waste: environmentalists

----- Original Message -----
From: Gordon Edwards
Sent: Sunday, September 29, 2013 3:24 PM
Subject: OPG unclear about nature of radioactive waste: environmentalists

Background:

High Level Radioactive Waste

High Level Radioactive Waste is a term that the nuclear industry reserves for only one kind of waste, and that is used nuclear fuel. It is more properly called irradiated nuclear fuel, as it is millions of times more radioactive than the fresh fuel that goes into the reactor to begin with.

The terms "spent fuel" and "used fuel" are misleading, as they suggest to the uninitiated that such material is relatively inert. Nothing could be farther from the truth.

You could stand one metre away from an unused nuclear fuel bundle for hours without getting a significant dose of atomic radiation; but if you stood one metre away from an irradiated fuel bundle, just after it is removed from the reactor, you would get a lethal dose of atomic radiation in less than 20 seconds. You would be dead a few days later.

The inventory of man-made radioactive poisons inside irradiated nuclear fuel consists of over 200 different varieties of radioactive
elements that were not present in the natural environment prior to the detonation of nuclear weapons and/or the operation of nuclear
reactors. These atoms are all unstable, meaning that they are all disintegrating by undergoing subatomic explosions that give off alpha particles, or beta particles, or gamma rays, all of which are very harmful to living things because they damage the genetic instructions in a living cell.
See [ http://ccnr.org/hlw_chart.html ].

Most of the dangerous materials in irradiated fuel are "fission products" -- the broken pieces of atoms that have been "split" (to release the energy needed to boil water so as to create steam that is then used to turn the blades of a turbine to generate electricity). These fission products are so intensely radioactive that they can heat up the core of the reactor to the melting point, causing a complete core meltdown, even after the reactor itself has been completely shut off. Most fission products have relatively short half-lives, measured in hours, days, years or centuries. The "half-life" of any radioactive material is the time needed for half of its atoms to undergo atomic disintegration.

But irradiated fuel also contains man-made elements called "transuranics" -- so called because they are heavier than uranium (uranium is the heaviest element that is naturally-occurring). The transuranics include varieties of plutonium, neptunium, americium, curium, and others. Most of these materials do not give off much penetrating gamma radiation, but they are in general much more radiotoxic than the fission products if they enter the body through ingestion, inhalation, or absorption through the skin.

Transuranic elements often have radioactive half-lives that are measured in millennia rather than mere decades or centuries. For example, plutonium-239 has a half-life of 24,000 years -- and when an atom of plutonium-239 disintegrates it turns into an atom of uranium-235 which has a half-life of 700 million years!

Besides fission products and transuranics, there are also "neutron activation products". These are made up of radioactive atoms that
are created in (for example) the metal cladding of the fuel when a non-radioactive atom in the metallic crystalline structure absorbs a neutron or two and is thereby transmuted into a radioactive atom. One of the more troublesome activation products is cobalt-60, a very intense gamma-emitting material that poses serious dangers for plant workers -- especially since it migrates through the cooling system and contaminates pipes far away from the core area.

Refurbishment Wastes

When a CANDU nuclear reactor is refurbished, all of the small diameter piping that runs through the core of the reactor (pressure tubes and
calandria tubes) as well as the small diameter piping that leads from the superheated water from the core of the reactor to the nuclear boilers (called "steam generators") is removed and replaced with new piping.

Workers must operate inside heavy lead cages to protect themselves from the blast of gamma radiation from the in-core tubing. These
metallic components have become highly radioactive and will remain dangerous for tens of thousands of years. Many of the atoms in the
crystalline structure of the metal itself have become "activated" -- that is, transmuted into highly unstable and therefore intensely radioactive atoms. This process, called "neutron activation", occurs only in the core area of the reactor (where neutrons are abundant during normal operation and therefore neutron bombardment takes place constantly).

Pipes outside the core area, such as "feeder pipes", do not undergo much neutron activation but they do become contaminated with fission products and transuranics that "leak" out of fuel bundles in the core of the reactor (due to tiny pinholes and cracks in the fuel cladding) as well as activation products that are flushed out of the core area by the flow of the primary coolant. These radioactive contaminants are deposited on the inside surfaces of all pipes in the primary cooling system, so that all of them (about 7 to 9 km of piping in each CANDU!) become intermediate level radioactive wastes.

Although steam generators are too far from the core to get "activated", each steam generator contains 5000 narrow tubes used for heating
purposes, and those internal pipes do get contaminated with radioactive materials that are flushed out of the reactor core by the primary coolant.
See [ http://ccnr.org/Tubes_in_SG.pdf ]

Published data from Bruce Power shows that very long-lived radioactive poisons remain trapped in the piping of the steam generators. For example, plutonium-239. It has a half-life of 24,000 years, and will remain dangerously radiotoxic for ten or twenty times longer than that. It turns out that 90% of the mass of radioactivity in a given steam generator is made up of five plutonium isotopes, and the plutonium-239 from just one of these steam generators would be enough, in principle, to give over 4 million atomic workers their maximum permissible lifetime body burden of plutonium. See [ http://ccnr.org/SG_plutonium_CNSC.pdf ].

The steam generators weigh about 100 tonnes each, and there are 8 in each Bruce reactor, so that's 8x8 = 64 tonnes of radioactive waste.
But now Bruce Power is replacing the steam generators in their reactors so there will be 128 steam generators just from the Bruce station alone. Add all the steam generators from Pickering and Darlington and you have quite an inventory of radioactive garbage -- long-lived intermediate level radioactive waste that will remain radiotoxic for hundreds of thousands of years.

Decommissioning Wastes

After all the irradiated fuel and radioactive piping have been removed, there are still a number of massive structures in the core itself, all of them intensely radioactive waste material -- for example, the calandria vessel, the stainless steel heat shields, the concrete biological shields, and the various cooling systems (e.g. for moderator and end shields). All in all, thousands of truckloads of radioactive rubble, constituting the decommissioning wastes from each nuclear power reactor. And since no Canadian power reactor has ever had its core dismantled, it is very much a guessing game as to how much waste will result from such an operation. Yet OPG wants permission now -- sight unseen, and realistic assessments not yet available -- to include all those decommissioning wastes in the DGR as well.

Originally, when the DGR project was first proposed, it was only intended for low-level waste and short-lived intermediate-level waste; but OPG, seeing a golden opportunity to take advantage of people's carefully cultivated ignorance of the nature of nuclear wastes, has now decided to try to cram everything into that hole in the ground -- except for the irradiated nuclear fuel, which is a federal responsibility under the Nuclear Waste Policy Act.

Gordon Edwards.

===================================

OPG unclear about nature of radioactive waste: environmentalists

[ http://www.thestar.com/business/2013/09 ... lists.html ]

Environmental law association says OPG has not ruled out storing decommissioning waste also at proposed Lake Huron disposal site.

Decommissioning waste includes reactor cores – though not the fuel they once contained. Some of the material is highly irradiated, and would
remain so for tens of thousands of years.

By: John Spears, Business reporter, Toronto Star, Sep 17 2013

[ http://tinyurl.com/p4pk428 ]

KINCARDINE—Ontario Power Generation has made apparently conflicting statements about just what it proposes to put in a nuclear waste disposal site beside Lake Huron, says an environmental group.

The Canadian Environmental Law Association has submitted a formal request to a federal panel examining OPG’s proposed waste site, asking the panel to state clearly what would be going into the site.

At the moment, “it’s completely a moving target,” the association’s Theresa McClenaghan said in an interview outside the hearing.

The panel can’t do its job, and the public can’t judge the project until OPG makes a “complete, comprehensive and frank” statement, the association says in its submission to the panel.

The panel should adjourn its hearing if OPG is expanding the scope of the site, the association argues.

OPG has said the site, to be carved into rock 680 metres below the surface at the Bruce nuclear station, will hold low- and intermediate-level waste produced by operating nuclear plants in Ontario.

But it’s not currently designed to take waste from decommissioned plants, which will eventually be torn apart and disposed of in a still undetermined way.

Decommissioning waste includes reactor cores – though not the fuel they once contained. Some of the material is highly irradiated, and would remain so for tens of thousands of years.

But the association brief quotes statements from OPG officials at a hearing in August saying that decommissioning waste might also wind up at the Bruce site.

That would significantly increase the amount of waste going into the site.

MORE:

[ http://www.thestar.com/business/2013/09 ... lists.html ]

[Oscar]

Zirconium Fire like a Cluster Bomb: Nuclear waste plan unsafe, panel hears

[ http://www.theglobeandmail.com/news/nat ... d/follows/ ]

by Shawn McCarthy, The Globe and Mail, Monday, Jul. 14 2014

http://tinyurl.com/o3goono

Last updated Monday, Jul. 14 2014, 8:12 PM

QUOTE: “At the same time, a federal group, the Nuclear Waste Management Organization is canvassing towns in Ontario and Saskatchewan for a deep repository of high-level nuclear waste – essentially the spent fuel rods from reactors that will remain dangerous for hundreds of thousands of years.”

EDTA retired nuclear scientist has slammed Ontario Power Generation over its proposed $1-billion nuclear waste burial site on Lake Huron, saying the utility’s safety assessment contains some dangerous errors.

In a submission to a federal review panel, nuclear chemist Frank Greening said OPG’s contractors seriously underestimated the potential impacts of a bombing in the vicinity of pressure tubes that have been removed from reactors and stored as waste. In contrast to OPG assurances, Dr. Greening said the zirconium in the tubes would burn fiercely, setting off chain reactions similar to those in cluster bombs.

“I think this is quite alarming, what I’m suggesting could happen and what they seem to have entirely missed,” he said in an interview Monday. “This absolutely affects the safety case … This is the design of a cluster bomb, this is an incendiary weapon waiting to happen. In fact, I think this is absolutely reckless on their part.”

The provincial Crown corporation has proposed to bury some 200,000 cubic metres of low- and intermediate-level nuclear waste from its fleet of reactors in a deep repository some 680 metres beneath the surface. The site is located at the Bruce Power Plant on the shores of Lake Huron, and many local residents are fiercely opposed to its construction, fearing possible contamination of the nearby Great Lakes and the increased traffic of trucks hauling radioactive material.

The federal panel has scheduled more hearings this fall. OPG will deal with Dr. Greening’s critique at those hearings, spokesman Neal Kelly said. “The process allows for a healthy discussion,” he said. “That will ensure the best outcome.”

Dr. Greening was a research scientist for OPG’s predecessor, Ontario Hydro, for more than 20 years until 2000, and has worked more recently as a consultant for Bruce Power. He has been a frequent critic of OPG and the Canadian Nuclear Safety Commission (CNSC) which – along with the Canadian Environmental Assessment Agency – is conducting the hearings.

In a previous submission, the scientist argued that OPG had underestimated the radioactivity of some of the intermediate-level waste to be stored at the site, though he agreed with CNSC scientists that even his higher assessment fell within acceptable levels. But in an interview Monday, he argued the panel should have required OPG to do a full review of their methods to determine whether there are other fundamental errors.

MORE:

[ http://www.theglobeandmail.com/news/nat ... d/follows/ ]