Waste Management

What Is It?

Almost all activities, from making dinner to driving cars, produce “waste”, an unusable or undesirable leftover material. The term “nuclear waste” tends to be applied to all radioactive material that is discarded from any nuclear activity.

This can include a variety of items, from slightly contaminated clothing, instruments and equipment, to the highly radioactive spent fuel from nuclear reactors. The common factor is radioactivity.

Radioactive waste is generally divided into three categories: low; intermediate; high, depending on the level of radioactivity.

Types of Waste
Waste Type
What it Includes
Low-level waste
 Mops, rags, paper towels, temporary floor coverings, floor sweepings, protective clothing, and hardware items such as tools
Intermediate-level waste
 Used reactor core components, and resins and filters used to keep reactor water systems clean
High-level waste
Spent fuel

How is Nuclear Waste Managed?

nuclear waste
Worker handling low-level waste from a nuclear power plant.

Low-level waste, such as that from hospital nuclear medicine departments, contains only small amounts of radioactive materials that have short half-lives. This means the radioactivity decays away in hours or days. After holding it until the radioactivity has decayed that waste can be treated in some cases like ordinary hospital garbage or in other cases may need to be incinerated.

Some low-level waste from activities other than nuclear power plants, which is contaminated with long-lived radioisotopes above a very low amount, are shipped to special disposal sites, such as that operated by Canadian Nuclear Laboratories (CNL) at its Chalk River Laboratories. Typical disposal facilities for this type of waste involve lined concrete bunkers.

A worker at the Pickering Nuclear Station
A worker at the Pickering Nuclear Station looks over the used fuel bundles in the water-filled bay. The fuel bundles will remain in the water for about 10 years.

Low and intermediate waste from the nuclear power plants in New Brunswick and Quebec are stored on-site in special containers of concrete and other materials. In Ontario all low and intermediate waste from all of Ontario’s nuclear power plants are shipped to a dedicated storage facility located adjacent to the Bruce nuclear generating stations near Kincardine, Ontario. Ontario Power Generation (OPG) is proposing to build an underground permanent storage facility at this site for these wastes.

High level waste such as spent nuclear fuel from nuclear power plants is initially stored in large water-filled pools. The water provides shielding from the radiation and cooling to remove the heat generated by the radioactive material in the spent fuel.  Immediately after removal from the reactor, the fuel bundle continues to generate about 6% of the heat it did in the reactor – this power level decays to about 2% after a few hours. After a year, it is generating less than 0.1% of the heat it generated in the reactor, or about 100 W per fuel bundle.

In terms of radioactivity, when removed from the reactor, the fuel bundle would deliver a radiation dose of about 50-60 sievert per hour (Sv/h) at a distance of 30 centimetres without shielding.  This dose rate is lethal in minutes. It is important to make sure that people are shielded from this radioactivity and that it cannot escape into the environment.

nuclear waste
Stacked like cordwood, all of Canada’s used nuclear fuel could fit into six hockey rinks..

A CANDU fuel assembly is approximately 0.5 metres long. Stacked like cordwood, all of Canada’s used nuclear fuel could fit into six hockey rinks.

After 100 years, this drops to about 0.3 Sv/h, and after 500 years to 1 millisievert per hour (mSv/h).  Spending an hour near the fuel bundle after 500 years would provide a dose of radiation that is thousands of times smaller than what would lead to physical harm.

After a few years the used fuel may be removed from the pools and placed in dry storage inside concrete canisters or structures.  The fuel can safely be stored in this manner for periods exceeding 50 years.

used fuel
After being removed from the water-filled bays, the used fuel is placed in storage canisters like the ones shown here. The containers are stored on the site of the nuclear station in highly secure warehouses where they are constantly monitored.

Long-term Management

At this time there is no urgency to build a permanent disposal facility for spent nuclear fuel in Canada because dry storage facilities can provide safe storage for many decades. The Nuclear Waste Management Organization (NWMO), established in 2002 by Canada’s nuclear electricity generators to develop with Canadians a management approach for the long-term care of Canada’s used nuclear fuel recommended to the federal government in November 2005 an  a plan called “Adaptive Phased Management”. This a long-term strategy for managing used nuclear fuel was accepted by the government in 2007 and the plan is now being implemented.

Adaptive Phased Management features:

adaptive phased management
Adaptive phased management.

 

  • Centralized containment and isolation of used nuclear fuel in a deep geological repository in a suitable rock formation Optional shallow underground storage facility if required
  • Continuous monitoring with the potential for retrieval for an extended period of time
  • An open, inclusive and transparent implementation process with collaborative and phased decision-making
  • Seek an informed and willing community to host the central facility
  • Focus site selection in provinces directly involved in the nuclear fuel cycle

The NWMO is currently working collaboratively with interested Canadians to develop a fair process to select a site for a deep geological repository.  Several countries, such as Finland and Sweden, are proceeding with the development of geologic disposal facilities. The United States has identified Yucca Mountain in Nevada as the site for deep geological storage.

Adaptive Phased Management allows for adopting alternative methods of dealing with used nuclear fuel to benefit from innovations in technology or changing societal priorities.

One of these alternate methods is to recycle a large portion of the fuel as new fuel (a step also called “reprocessing”), which has the potential to extract about 100 times more energy from the used fuel.  This possible recycling step is, in fact, why it is more correct to refer to the nuclear fuel coming out of a conventional reactor as “used”, and not “spent”.

Is Nuclear Waste Dangerous?

The radiation from high-level radioactive waste can be dangerous. That is why it is handled remotely and stored in suitable, monitored and regulated facilities.

The used fuel produced by Canadian power plants to generate electricity is controlled and stored in licensed and carefully managed facilities at the nuclear power plants.  In Canada’s 48 years of using nuclear energy, no member of the public has been harmed as a result of a radiation leak from a nuclear power plant or waste storage facility.

Canada’s plan for long-term care of used nuclear fuel includes storage at reactor sites and long-term and retrievable geological storage. “Retrievable” is important because 99% of the energy in the used fuel is still available. It is the hope that future nuclear reactors will re-use this fuel for future electricity production as it is a valuable and precious resource for powering the world. Retrievability is also important for those who are concerned about possible damage to the containment systems or to allow for the possibility of technological advances that provide better ways of dealing with the waste in the future.

Canada’s management of its used nuclear fuel is highly regulated. The nuclear industry knows exactly where all its used fuel is stored. It is not only managed and monitored domestically but internationally through the International Atomic Energy Agency.

About 85,000 used nuclear fuel bundles are generated in Canada each year. As of June 30, 2008, the number of used nuclear fuel bundles stored at Canadian nuclear facilities was:

Used Fuel in Canada
Facility
Location
Stored Bundles
Pickering
Ontario 581,130
Bruce B
Ontario 474,819
Bruce A
Ontario 393,429
Darlington
Ontario 333,880
Point Lepreau
New Brunswick 121,758
Gentilly-2
Quebec 108,581
Douglas Point
Ontario 22,256
CNL-Chalk River Laboratory
Ontario 4,886
CNL-Gentilly-1
Quebec 3,213
CNL-Whiteshell Laboratory
Manitoba 2,268
TOTAL
CANADA 2,046,220

Sources:

Radioactive Waste Management, World Nuclear Association, world-nuclear.org/info/inf04.html.
J.J. Whitlock, 2011, Section E: Waste Management, The Canadian Nuclear FAQ,www.nuclearfaq.ca/cnf_sectionE.htm.
Tammemagi, Hans and Jackson, David (2002), Unlocking The Atom: The Canadian Book on Nuclear Technology, McMaster University Press, p. 138-146.
Nuclear Waste Management Organization, www.nwmo.ca.