World Library  
Flag as Inappropriate
Email this Article

Thtr-300

Article Id: WHEBN0003113304
Reproduction Date:

Title: Thtr-300  
Author: World Heritage Encyclopedia
Language: English
Subject: AVR reactor, Philippsburg Nuclear Power Plant, List of nuclear power accidents by country, List of power stations in Germany, Gundremmingen Nuclear Power Plant
Collection:
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Thtr-300

THTR-300
Cooling tower of the THTR-300 (demolished in 1991)
Country Germany
Coordinates
Construction began 1971
Commission date November 16, 1985
Decommission date April 20, 1988
Owner(s) HKG
Operator(s) HKG
Nuclear power station
Reactor type PBR
Power generation
Units decommissioned 1 x 308 MW
Nameplate capacity 308
Annual generation 1,083 GW·h
Website

The 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.[1]

Operations started on the plant in Hamm-Uentrop, Germany in 1983, and it was shut down September 1, 1989. The THTR was synchronized to the grid for the first time in 1985 and started full power operation in February 1987.[2]

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 TRISO pebble fuel. The THTR-300 cost 2.05 billion and was predicted to cost an additional €425 million through December 2009 in decommissioning and other associated costs.

History

The electrical generation part of the THTR-300 was finished late due to ever-newer requirements and licensing procedures. It was constructed in Hamm-Uentrop from 1970 to 1983 by Hochtemperatur-Kernkraftwerk GmbH (HKG).[1] 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 9, 1985, but 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 helium-cooled high-temperature reactor with a pebble bed core consisting of approximately 670,000 spherical fuel compacts each 6 centimetres (2.4 in) in diameter with particles of uranium-235 and thorium-232 fuel embedded in a graphite matrix. The pressure vessel that contained the pebbles was prestressed concrete (the first time this had been used for the type of reactor, rather than the usual 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; 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 308 megawatts of electricity. The waste heat from the THTR-300 was exhausted using a dry cooling tower.

Decommissioning

On September 1, 1989, the THTR-300 was deactivated due to its rising cost; in August 1989, the THTR company became almost bankrupt after a long shut down time due to broken components in the hot gas duct. It had to be bailed out by the government with an amount of 92 million Marks.[3]

THTR-300 was only in full service for 423 days. On May 4, 1986, just 6 months after it was connected to the power grid, a fuel pebble became lodged in a fuel feed pipe to the reactor core. As a result, some radioactive dust was released to the environment. This happened just a couple of days after the Chernobyl disaster. The operators played down the incident, which caused a loss of trust in the controlling authority. The Westphalia ministry of commerce created a fact finding committee. After a couple of weeks the power plant was switched on again, but the former supporters withdrew their backing. The reactor kept experiencing technical difficulties, with fuel elements breaking more often than anticipated. The fuel factory in Hanau was decommissioned for security reasons. The fuel supply was already difficult before this decision, and now it was truly at risk. It was decided to shut down THTR-300. 80 incidents were logged in its short lifetime.[4]

On October 10, 1991, the 180-metre (590 ft) high dry cooling tower, which at one time was the highest cooling tower in the world, was explosively dismantled and from October 22, 1993 to April 1995 the remaining fuel was unloaded and transported to the intermediate storage in Ahaus. The remaining facility was "safely enclosed" and dismantling will not start before 2027.

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 1992, a group of firms planned 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. As with other inactive reactor facilities, costs are still being incurred. For 2013 to 2017 23 Mio Euro are budgeted to lighting, guarding and the storage of the pellets in the interim storage Ahaus. The destruction cannot begin before 2022 because of radioactivity. The cost for the demolition are estimated to be hundreds of millions of euros, and it is not clear who should pay.[4]

See also

References

  1. ^ a b
  2. ^
  3. ^
  4. ^ a b Westfälischer Anzeiger 13. September 2013 THTR: Das Milliardengrab von Uentrop wird 30 http://www.wa.de/lokales/hamm/uentrop/thtr-milliardengrab-hamm-uentrop-wird-jahre-3099260.html.

External links

General

  • THTR homepage (German)
  • Cooling Tower of the Schmehausen Nuclear Plant at Structurae
  • IAEA HTGR Knowledge Base

IAEA technical documents

  • The THTR steam generator: design, manufacture and installation
  • Gas-cooled reactor safety and licensing aspects
  • THTR steam generator licensing experience as seen by the manufacturer
  • Accident analysis and accident control for the THTR - 300 power plant
  • Aspects of water and air ingress accidents in HTRs
  • Safety concept of high-temperature reactors based on the experience with AVR and THTR
  • The behaviour of spherical HTR fuel elements under accident conditions
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.