Databank

POSIVA Report 1996-12

Back

Name:

Assessment of Alternative Disposal Concepts

Writer:

Jorma Autio; Timo Saanio; Pasi Tolppanen; Heikki Raiko; Timo Vieno; Jukka-Pekka Salo

Language:

English

Page count:

109

ISBN:

951-652-011-1; 1239-3096

Summary:

Working report: ASSESSMENT OF ALTERNATIVE DISPOSAL CONCEPTS




Four alternative repository designs for the disposal of spent nuclear in the Finnish crystalline
bedrock are assessed. The alternatives are: the basic KBS-3 design in which copper canisters are
emplaced in vertical deposition holes bored in the floors of horizontal tunnels; the KBS-3-2C
design with two canisters in a deposition hole; Short Horizontal Holes (SHH) in the side walls of
the tunnels; and the Medium Long Holes (MLH) concept in which approximately 25 canisters are
emplaced in a horizontal deposition hole about 200 metres in length bored between central and
side tunnels. In all the alternatives considered, the thickness of the layer of compacted bentonite
between copper canister and bedrock is 35 cm.

Two different copper canister designs are assessed. The Advanced Cold Process (ACP) canister
consists of an inner container of carbon steel as a load-bearing element and an outer container of
oxygen-free copper to provide a shield against corrosion. Empty space in the steel container is
filled with a granular material, such as quartz sand, glass beads or copper spheres. In the cast
insert canister design, all the internals inside the copper overpack are substituted with an integral
cast inner component with holes for the emplacement of fuel assemblies. Several variants of
canister with different sizes, filling materials and gas inside the inner container have been
designed for Olkiluoto’s BWR and Loviisa’s VVER-440 type PWR fuel.

Technical feasibility and flexibility, post-closure safety and repository cost are assessed for each
of the alternative canister and repository designs. On the basis of this assessment it is
recommended that further development and studies should focus on the vacuum- or inert gas-filled
cast insert type copper canister and the basic KBS-3 type repository design with a single canister
in a vertical deposition hole. The KBS-3 design is robust and flexible and provides excellent post-
closure safety. The transfer, emplacement and sealing operations are technically uncomplicated.
The alternative options assessed do not offer any significant benefits in safety or cost over the
basic design, but they are technically more complex and also in some respects more vulnerable to
malfunction during the emplacement of canisters and buffer, as well as common mode failures.
ASSESSMENT OF ALTERNATIVE DISPOSAL CONCEPTS




Four alternative repository designs for the disposal of spent nuclear in the Finnish crystalline
bedrock are assessed. The alternatives are: the basic KBS-3 design in which copper canisters are
emplaced in vertical deposition holes bored in the floors of horizontal tunnels; the KBS-3-2C
design with two canisters in a deposition hole; Short Horizontal Holes (SHH) in the side walls of
the tunnels; and the Medium Long Holes (MLH) concept in which approximately 25 canisters are
emplaced in a horizontal deposition hole about 200 metres in length bored between central and
side tunnels. In all the alternatives considered, the thickness of the layer of compacted bentonite
between copper canister and bedrock is 35 cm.

Two different copper canister designs are assessed. The Advanced Cold Process (ACP) canister
consists of an inner container of carbon steel as a load-bearing element and an outer container of
oxygen-free copper to provide a shield against corrosion. Empty space in the steel container is
filled with a granular material, such as quartz sand, glass beads or copper spheres. In the cast
insert canister design, all the internals inside the copper overpack are substituted with an integral
cast inner component with holes for the emplacement of fuel assemblies. Several variants of
canister with different sizes, filling materials and gas inside the inner container have been
designed for Olkiluoto’s BWR and Loviisa’s VVER-440 type PWR fuel.

Technical feasibility and flexibility, post-closure safety and repository cost are assessed for each
of the alternative canister and repository designs. On the basis of this assessment it is
recommended that further development and studies should focus on the vacuum- or inert gas-filled
cast insert type copper canister and the basic KBS-3 type repository design with a single canister
in a vertical deposition hole. The KBS-3 design is robust and flexible and provides excellent post-
closure safety. The transfer, emplacement and sealing operations are technically uncomplicated.
The alternative options assessed do not offer any significant benefits in safety or cost over the
basic design, but they are technically more complex and also in some respects more vulnerable to
malfunction during the emplacement of canisters and buffer, as well as common mode failures.

Keywords:

File(s):

Assessment of Alternative Disposal Concepts (pdf) (5.1 MB)


Back


Share article:
This website stores cookies on your computer. These cookies are used to improve our website and provide more personalised services to you.
Close

Cookies

To make this site work properly, we sometimes place small data files called cookies on your device. Most big websites do this too.

1. What are cookies?

A cookie is a small text file that a website saves on your computer or mobile device when you visit the site. It enables the website to remember your actions and preferences (such as login, language, font size and other display preferences) over a period of time, so you don’t have to keep re-entering them whenever you come back to the site or browse from one page to another.

2. How do we use cookies?

A number of our pages use cookies to remember your actions and preferences (such as login, language, font size and other display preferences.)

Also, some videos embedded in our pages use a cookie to anonymously gather statistics on how you got there and what videos you visited.

Enabling these cookies is not strictly necessary for the website to work but it will provide you with a better browsing experience. You can delete or block these cookies, but if you do that some features of this site may not work as intended.

The cookie-related information is not used to identify you personally and the pattern data is fully under our control. These cookies are not used for any purpose other than those described here.

3. How to control cookies

You can control and/or delete cookies as you wish – for details, see aboutcookies.org. You can delete all cookies that are already on your computer and you can set most browsers to prevent them from being placed. If you do this, however, you may have to manually adjust some preferences every time you visit a site and some services and functionalities may not work.

Close