FIVE DECADES OF TRIGA REACTORS

H. Böck, M. Villa, R. Bergmann Technical University Vienna

Atominstitut

Content

• History of TRIGA reactors • Status as of Sept 1st • Topics of concern

–Fuel front end situation – Fuel back end situation –Refurbishments –Utilization

• Conclusions

• Atoms for Peace was the title of a speech delivered by U.S. President Dwight D. Eisenhower to the UN General Assembly in New York City on December 8, 1953.

TRIGA HISTORY (1)

• The TRIGA was developed to be a reactor that, in the words of Frederic de Hoffmann, (Director of General Atomics), was designed to be “safe even in the hands of a young graduate student.” • Edward Teller headed a group of young nuclear physicists in San Diego in summer 1956 to design a reactor which could not, by its design, suffer from a meltdown. •The design was largely the suggestion of Freeman Dyson.

TRIGA HISTORY (2)

• TRIGA®

Training Research Isotope Production General Atomic

TRIGA HISTORY (3)

Original 10 kW TRIGA in San Diego

• The first three reactors started in 1958, just

two years after the idea was conceived • The prototype TRIGA reactor (TRIGA Mark I)

was commissioned on 3 May 1958* in San Diego and operated until shut down in 1997.

• The 2nd TRIGA which operated at the second Geneva Conference for peaceful Uses of Atomic Energy (Sep 1-13)

• The 3rd TRIGA started at the University of Arizona (Dec 7)

*It has been designated as a nuclear historic landmark by the American Nuclear Society.

TRIGA HISTORY (4)

Second Geneva Conference 1958

TRIGA Original Patent

• Totally 66 TRIGA type reactors were built in

23 countries • Today according to the IAEA Research Reactor

Data Base by mid of 2016 38 TRIGA reactors or converted facilities using TRIGA Type fuel are still in operation

TRIGA Stamp in Korea 1962

MANY TYPES OF TRIGA REACTORS

Moveable Core Mark III Munich, Germany

MTR Conversion University of Maryland Underground Mark I

General Atomics

Above ground Mark II Pavia, Italy

High Power Pulsing Reactor Tokai Mura, Japan

14 MW MultipurposeReactor Romania

FUEL TECHNOLOGY FOR TRIGA® REACTORS

• UZrHx metallic alloy fuels were first developed for satellite use — early 1950

• Development continued at GA for research reactors — late 1950- “warm neutron principle”

• Early fuels were LEU (19.7% U-235) with low density (<1.0 gU/cm3). HEU used where extended core life was required.

• Higher density LEU fuels for high power regimes with long core life are now in use — early 1980

Standard Triga Fuel element: diameter ~ 36 mm

High power Triga fuel element: diameter ~13mm

It all started 1970 in Helsinki

List of TRIGA Users Conferences • 1970 Feb 19-20 Denver, USA • 1970 Aug 25-27 Otaniemi, Finland • 1972 Fen 21-22 College Station,USA • 1972 Sept 12-15 Pavia,Italy • 1974 Feb 25-27 Albuquerque,USA • 1974 Oct.29-31 Neuherberg, Germany • 1976 March 1-3 Salt Lake City, USA • 1976 Sept 28-30 Vienna, Austria • 1977 Feb 28-1.3 Tucson, USA • 1978 Feb 28-2.3 Corvallis, USA • 1978 Sept 4-6 Portoroz, Yugoslavia • 1980 March 2-5 San Diego, USA • 1980 Sept 16-18 Mainz, Germany • 1982 March 8-10 Idaho Falls, USA • 1982 Sept 15-17 Istanbul, Turkey • 1984 March 12-14 Anaheim, USA • 1984 August 21-23 Espoo, Finland • 1986 April 6-9 College Station, USA • 1986 Oct 7-9 Casaccia, Italy • 1988 Apr. 10-13 Washington DC, USA • 1988 Sept 14-16 Vienna, Austria

List of TRIGA Users Conferences • 1990 March 11-14 Austin, USA • 1990 Sept. 11-13 Heidelberg, Germany • 1992 May 18-20 Ithaca, USA • 1992 Sept 28-Oct1 Pitesti, Romania • 1994 Sept 26-28 Ljubljana, Slovenia • 1996 Sept 22-25 Mainz, Germany • 1998 June 15-17 Espoo, Finland • 2000 Sept 25-28 Pitesti, Romania • 2002 June 17-20 Pavia, Italy 1.World TRIGA Users Conference • 2004 Sept 15-18 Vienna, Austria • 2006 Aug 21-25 Belo Horizonte, Brazil • 2008 Sept 8-10 Lyon, France • 2009 March 22-25 Vienna, Austria • 2010 March 22-24 embedded in RRFM 2010 Marrakesh, Morocco • 2011 March 20-24 embedded in RRFM 2011 Rome, Italy • 2012 March 18-22 embedded in RRFM 2012 Prague, Czech Republic • 2013 April 21-25 embedded in RRFM 2013 St.Petersburg, Russia

1972 Pavia 1986 Rome 1988 Vienna

1990 Heidelberg 1990 Sacramento 2008 Lyon

Ljubljana Mainz Mexico

Pitesti

Rabat

Pavia

Vienna

Fuel front end situation (1) • From the initial period in 1950ies up to mid-

1990ies the TRIGA fuel elements were manufactured by General Atomics in the USA

• In 1996, GA entered into a joint venture with CERCA/France to relocate its fuel manufacturing facility from the USA to the CERCA site in Romans, south of Lyon/France

• The new TRIGA fuel production facility at CERCA delivered fuel elements for all the HEU to LEU core conversions both in the US and internationally

Fuel front end situation (2) • This conversion campaign ended in 2014, where

upon CERCA stopped its TRIGA fuel production temporarily to make post-Fukushima safety upgrades mandated by the French regulatory authority.

• Currently fuel fabrication facility is expected to resume operations in late 2018 or early 2019.

• However CERCA announced that it needs at least firm fuel orders for about 100 fuel elements per year in order run the TRIGA fuel production economically

Fuel back end situation (1) • Originally in 1960ies USA agreed to take back

all fuel elements at the end of use, this was part of the reactor purchase contract

• A policy change happened in the early 1990ies when the USDOE stated that this take back guarantee starts in 1996 and ends by 2006

• Each TRIGA user has to shut down its TRIGA by May 13, 2006 and has three years time to return his fuel to the US, otherwise the host country has to care for a national fuel storage facility

Fuel back end situation (2) • A legal intervention by an European Research

Reactor group was successful leading to an extension of another 10 years from May 13, 2006 to May 13, 2016.

• This would be the last day to operate a research reactor, with a follow-up fuel return period to May 13th 2019.

• Any facility operating beyond May 13th 2016 has to store their research reactor fuel in their national storage facility.

• Exists there any other solution ????

YES i.e. To re-use low burnt, US stored TRIGA fuel in operating TRIGA reactors

as an example: in the TRIGA reactor Vienna

• First contacts ATI-DOE April 2011 • Full support of IAEA and by Austrian Government to continue beyond

2016 • Technical and political activities in parallel • 19.September 2011 „Memorandum of Understandung“ USA-Austria

with presence of IAEA DG Amano • TRIGA Reactor Vienna shut down end of April 2012 • Fuel inspection by DOE in Vienna June 2012 • Fuel inspection by ATI in INL 2 weeks Aug/Sept. 2012 • Fuel transport of 77 slightly burned TRIGA LEU SST to Vienna via

Koper 30.October 2012 • New FE (77) from INL to Vienna and 91 (FE) from Vienna via Koper to

INL, departure from Vienna 7.November 2012 • 1.Criticality 27.November 2012

Refurbishments

• At TRIGA reactors practically all systems or components can be replaced or refurbished

• Updating and modifications are necessary to follow the national and international safety requirements

• With proper house keeping and maintenance typical systems to be refurbished in regular intervals are the I&C system, primary- and secondary cooling systems, water make-up system or area monitoring system etc.

• Especially electronic based systems undergo a very fast development and therefore the I&C systems have to upgraded in periodic intervals

Three Generations of I& C Systems

Original Electronic Tube Type Reactor Instrumentation

1962 to 1968

Transistorized Reactor Instrumentation 1968 to 1992

Digital Reactor Instrumentation 1992 to 2015

Fourth Generation of I&C Systems

Utilization • Education and training, basic and applied research in: • Nuclear Technology • Radiochemistry • Neutron Activation Analysis • Radioisotope Production • Nuclear Physics • Neutron Beam Application incl. Neutron Radiography and BNCT • Safeguards • Radiation Protection and Dosimetry • Geology • Biology • ......and many more fields

NAA & Radiosiotope Production • Ultra short lived NAA (Mainz) • Radioisotope production equal or above 2 MW

(i.e. Bangladesh) • Geochronology: academic research, example:

pumice distribution after the Santorin eruption 3500 years ago in the Eastern Mediterranean area (i.e. Vienna)

Transmutation Research

• Change of material properties through neutron/gamma irradiation

• Power level above 2 MW necessary (i.e. Pitesti, University of California)

• Gemstone colorization: to enhance or influence the colour of gemstones, in Europe not allowed but carried out at US and Asian TRIGA reactors

Neutron Radiography • Static- and/or real-time neutron radiography and

tomography • Carried out at many TRIGA reactors • TRIGA Sacramento was devoted only to NR of

aircraft wings • NR of nuclear fuel, moisture in building materials (i.e. Vienna)

NR of the end caps of a fresh WWER 440 fuel element 3.6% enriched

Neutron- and Solid State Physics

• Using radial, tangential or piercing beam ports or thermal column with various types of collimators installed

• Experiments such as ultra small angle neutron scattering, neutron diffraction and neutron interferometry (first demonstrated at TRIGA Vienna in 1974)

Boron Neutron Capture Therapy

• BNCT has been tested at many TRIGA reactors around the world

• Advantage of TRIGA reactors due to flexibility and simple design

• Easy access to irradiation position

• TRIGA reactor Finland was mainly devoted to BNCT (Final shut down May 2016)

NPP Operators Training • Practical training in reactor physics and kinetics

(neutron flux measurement, control rod calibration, temperature coefficient, void coefficient, subcritical multiplication)

• Practical training in reactor instrumentation (compensated ionization chambers, fission chambers, self-powered neutron detectors)

• Practical training in radiation protection (personnel monitoring, area monitoring, environmental monitoring)

Summary & Conclusions

• TRIGA type reactors are the most successful and outstanding nuclear research reactor types

• Even after more than 50 years, TRIGA reactors are far from being outdated

• They contribute to many areas of very important nuclear research

More than five decades of cooperation between the TRIGA family

All the best for the next decades!