THTR-300

Infobox NPP
Picture = Thtr300 kuehlturm.jpg
Pic_des = Cooling tower of the THTR-300 (demolished in 1991)
Country = Germany
EIGENTÜMER = HKG
Utility = HKG
Built = 1971
Start = November 16, 1985
End = April 20, 1988
Reactor =
S_Reactor = 1
Capacity = 308
El_Prod = 1,083
for_year = 1988
El_Prod_avg =
Net_Prod = 2,756
WEBSITE = [http://www.thtr.de/index.htm Official Site]
as_of = October 6, 2006The THTR-300 was a thorium high-temperature nuclear reactor rated at 300 MW electric (THTR-300). The German state of North Rhine Westphalia, in the Federal Republic of Germany, and Hochtemperatur-Kernkraftwerk GmbH (HKG) financed the THTR-300’s construction. [http://www.iaea.org/inis/aws/htgr/abstracts/abst_29059899.html Decommissioning of the thorium high temperature reactor (THTR 300)] ] Operations started on the plant in Hamm-Uentrop, Germany in 1983, and it was shut down September 1st, 1989 [http://www.iaea.org/inis/aws/htgr/abstracts/abst_iwggcr19_10.html The present state of the HTR concept based on experience gained from AVR and THTR] ] . The THTR was synchronized to the grid for the first time in 1985 and started full power operation in February 1987. Whereas the AVR was an experimental pebble bed high-temperature reactor (HTR) used to develop the pebble fuel the THTR-300 served as a prototype HTR to use the BISO pebble fuel. The THTR-300 cost €2.05 billion and is predicted to cost an additional €425 million until December 2009 in decommissioning and other associated costs.

History

The electrical generation part of the THTR-300 was finished late due to ever-newer editions and licensing procedures. It was constructed in Hamm-Uentrop from 1970 to 1983 by Hochtemperatur-Kernkraftwerk GmbH (HKG) . Dr. Heinz Riesenhuber, Federal Secretary of Research at that time, inaugurated it, and it first went critical on September 13, 1983. It started generating electricity on April 9th, 1985, however it did not receive permission from the atomic legal authorizing agency to feed electricity to the grid until November 16, 1985.

Design

The THTR-300 was a high-temperature reactor with a pebble bed core, consisting of approximately 670,000 spherical fuel compacts each 6 cm in diameter with Uranium-235 and Thorium-232 fuel and core walls consisting of graphite and was helium cooled. The pressure vessel that contained the pebbles was pre-stressed concrete (This was the first time this had been used instead of a steel pressure vessel). The THTR-300's power conversion system was similar to the Fort St. Vrain reactor in the USA, in that the reactor coolant transferred the reactor core's heat to water. The thermal output of the core was 750 megawatts, this heat was transferred to the helium coolant which then transported its heat to water which then was used to generate electricity via a Rankine cycle. Because this system used a Rankine cycle, water could occasionally ingress into the helium circuit. The electric conversion system produced 307 megawatts of electricity. The waste heat from the THTR-300 was exhausted using a dry cooling tower.

Decommissioning

On September 1st, 1989 the THTR-300 was deactivated due to its cost and increased public scrutiny following both the Chernobyl accident and the THTR-300 fuel pellet event of May 4, 1985, in which a fuel pellet became lodged in a fuel feed pipe to thecore. On October 10th, 1991, the 180 meter high dry cooling tower, which at one time was the highest cooling tower in the world, was explosively dismantled and from October 22nd, 1993 to April 1995 the remaining plant was decommissioned.

From 1985 to 1989 the THTR-300 registered 16410 operation hours and generated 2891000 MWh according to a full-load working time of 423 days. By 1982 it was planned by a group of firms to proceed with construction of a HTR-500, the successor of the THTR-300, but up-rated to a thermal output of 1250 megawatts and an electrical output of 500 megawatts.

References

ee also

* Gas cooled fast reactor
* Pebble bed reactor
* Gas Turbine Modular Helium Reactor
* Anti-nuclear movement in Germany

External links

General

* [http://www.thtr.de/index.htm THTR homepage] de icon
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* [http://www.iaea.org/inis/aws/htgr/ IAEA HTGR Knowledge Base]

IAEA technical documents

* [http://www.iaea.org/inis/aws/htgr/abstracts/abst_iwggcr15_6.html The THTR steam generator: design, manufacture and installation]
* [http://www.iaea.org/inis/aws/htgr/abstracts/abst_iwggcr1.html Gas-cooled reactor safety and licensing aspects]
* [http://www.iaea.org/inis/aws/htgr/abstracts/abst_iwggcr1_04.html THTR steam generator licensing experience as seen by the manufacturer]
* [http://www.iaea.org/inis/aws/htgr/abstracts/abst_iwggcr1_03.html Accident analysis and accident control for the THTR - 300 power plant]
* [http://www.iaea.org/inis/aws/htgr/abstracts/abst_iwggcr1_17.html Aspects of water and air ingress accidents in HTRs]
* [http://www.iaea.org/inis/aws/htgr/abstracts/abst_389_26_1.html Safety concept of high-temperature reactors based on the experience with AVR and THTR]
* [http://www.iaea.org/inis/aws/htgr/abstracts/abst_iwggcr8_22.html The behaviour of spherical HTR fuel elements under accident conditions]