Youth Future Nuclear November 1st 2011
Fall Issue N 03
Nuclear going ahead
IN THIS ISSUE: Nuclear going ahead. Insight from a Retired IYNC General Co-chair. IYNC Network news. IYNC2012 Update. The nuclear program in Romania in the European context.
Youth Future Nuclear
IYNC Bulletin Committee Chair: Miguel Millan (Spain) Alumni: Hans Korteweg (Holland)
Editorial. â€œNuclear going aheadâ€?
Alumni Section: Marco Strait.
IYNC Network news
Country Report: Misha Swason (US)
Technical Articles: Silvia Ortega (Spain)
IYNC 2012: Craig Albers (US) IYNC News: J A Gonzalez (Fr)
Future Event: Lavinia Rizea (Romania) Student news: Mahima Gupta (US) Frontpage: Kristine Madden (US
Argentina, Australia, Austria, Belarus, Belgium, Bolivia, Brazil, Canada, Croatia, Czech Republic, Finland, France, Germany, Hungary, India, Israel, Italy, Japan, Korea, Lithuania, Mexico, Malaysia, Netherlands, Nigeria, Norway, Peru, Poland, Romania, Russia, Slovakia, Slovenia, South Africa, Spain, Sri Lanka, Sweden, Switzerland, Taiwan, Tanzania, United Kingdom, Ukraine, United States.
Youth Nuclear Future
Youth Future Nuclear Editorial “Nuclear going ahead” After the Fukushima Daiichi event, the world faced different types of reactions at the political level. On the one hand, the surprising quiet and measured Spanish president (auto-defined anti-nuclear) declared they would wait for the definition and results of “stress tests” before taking any action. On the other hand, we have witnessed the extreme reaction in Germany, where without any technical reason eight reactors were shutdown indefinitely.
Besides those unexpected reactions, plenty of countries have reiterated their intention to continue relying on nuclear power; new builds will remain on schedule and we have recently seen announcement of new construction of nuclear power plants. We must pay attention to Lithuania, where few years ago 73 % of their electricity production was nuclear. After Ignalina Nuclear Power Plant’s closure, Lithuania has to import most of their electricity. Therefore, they have announced the construction of a new plant and, last July, the government announced the election of a strategic investor to build this new project.
Other locations keeping their projects and construction alive are: China, where the first passive generation III unit is expected to be connected to grid in 2013; Czech Republic, where several vendors are preparing bids for new plans; United Kingdom, where the Generic Design Assessment is almost over and several utilities are ready to start construction. In this way, the preparation for the first US new-reactor in 30 years continues and the Combined Operating License (COL) is expected to be approved soon.
Before Fukushima, Germany was a net electricity exporter to surrounding countries. Within the period from January 1st until March 16th, the electricity exports/imports net balance was 85 GW•h in positive for Germany. After the German government’s reaction, the exportation sign changed. Within the period from March 17th until May 24th, the net electricity balance was -39,9 GW•h in negative for Germany. Meaning that Germany turned into an electricity dependent country, and it is remarkable that this dependence relies mainly on France. During this last period, Germany has imported 25 GW•h from French electricity or should we say nuclear GW•h.
In conclusion, as the Youth in Nuclear we need to inform our leaders to consider competitiveness, supply security and climate responsibility before taking extreme actions. Only Nuclear Energy can provide base load CO2 free electricity; therefore, this “climate clean” energy source should be a fundamental brick in the construction of a sustainable future and a must in our respective country’s energy portfolios.
IYNC Bulletin 1
Section 1: Editorial
Youth Future Nuclear Alumni Section: Insight from a Retired IYNC General Co-Chair Hans from Belgium asked me to write a short expose about my experiences as a retired IYNC General Co-Chair with the IYNC, so I try to give you a short inside view. There are many stories to tell, but at the moment I have not the time to write them down. This story started with an ENSYGN core group meeting in Vienna in February 2006. There, Martin from Sweden the General Co-Chair from IYNC2006 was reporting about the status quo of his conference and the call for a bid for the next one. As there was the golden rule that the congress should go around the world by jumping from continent to continent it was clear to all Europeans that we have not to prepare a bid for the next one. But… there were not enough bids, so Martin asked the core group to send in European bids. I looked at my very good friend Alexa and in this second we decided spontaneously to send in a bid. We thought we will never get it … but if it would be a perfect opportunity to celebrate the 10th anniversary of Swiss YG. The rest is history.
Personally I was in the perfect situation that my boss supported the idea and the whole work of the conference. So for me it was relatively easy to travel and to advertise the congress and I made many positive experiences during this period. For example I was once invited to Vienna to talk in an YG panel at an IAEA event. As I was a bit early to the panel, I looked around in the small exhibition and tried to advertise the IYNC. At a Japanese booth I met a Director of an institute and during the talk I learned that he had a friend, which was CEO of a railroad company in Switzerland. With this contact we could easily arrange the cultural trip at the end of the congress to the “Top of Europe”. As a German working in Switzerland I had to go to Austria to talk to a Japanese to get a contact in Switzerland, crazy world.
We won the bid, which was prepared only by the board of the Swiss YG. Luckily we had been a relatively big group of Swiss Youngsters in Stockholm and nearly all of them promised to help to organize the congress. So we found the local organizing team in Stockholm and they all did a great job over the coming years.
IYNC Bulletin 2
Section 2: Alumni Section
Youth Future Nuclear
From all that I learned one important thing: Even if we think we understand each other as we all live in a globalized world, this is not the case. The more we are living in a virtual world we have to meet and talk to each other. I learned that we should first try to understand each other before trying to convince the opposite from the own position. There is the possibility that both sides want the same but do not understand each other. So the international meetings had been the most important events in the preparation of the congress.
For me as General-Co-Chair the “hot” phase started 3 months before the conference. I suddenly recognized that I was responsible for ½ million Swiss Franc project. Of course I knew that from the very beginning, as I was involved in the budget, but at that time I realized what this means in reality – sleepless nights. The questions coming up: will all sponsors pay their fee? (btw. they didn’t, but luckily the most of them and the important did) which unpredicted things could happen during the congress? Will all artists come? And so on…. At that point I have to thank my wife Susanne and my daughter. They supported me during the whole time, especially in the last three months and those who had been in Interlaken might remember them. Susanne took over responsibility for the spouse program during the week.
IYNC Bulletin 3
The congress week itself was fantastic for the whole team. There were the official conference events, the sessions, the parties and the debriefing of the local team at night. Personally I went from highlight to highlight to the “Top of Europe” and the IYNC2008 was over. The week after I got an expression about the burnout syndrome. I was expecting to be down, but not as it was. I was recovering very soon and learned the lesson to be careful with my body. One year later I took my family and went for one week back to the area of Interlaken and visited all the places of the conference again. It was a great week and we remembered together what we experienced in 2008.
Since Korea is the closest country from Japan, the Fukushima nuclear accident is very seriously concerned in Korea more than other countries. The safety of nuclear power plants in Korea became one of the top issues with public fear against nuclear. Moreover, the media articles about the Fukushima accident and its prediction with uncertain information made the situation worse at the early stage of the accident.
Section 2: Alumni Section
Youth Future Nuclear Last year I attended IYNC2010 in Cape Town as a retired IYNC veteran. It was great just to come to this beautiful place attending the congress, meeting friends, partying and not being responsible for anything…. (it worked not like that but that is an other story). After IYNC2010 I changed job and I decorated my today’s office with the roll up of IYNC2008, which was at the “Top of Europe”. So at least a few minutes a day I remember the great experiences of IYNC 2006, 2008 and 2010 and I hope to see you in Charlotte.
Marco from Switzerland
IYNC Bulletin 4
Section 2: Alumni Section
Youth Future Nuclear IYNC Network news New countries in the Board of Directors. Polish YGN: Poland has been included in our Board of Directors: Marcin Brykała is the representative from Poland and she is the vi-president of the new Polish YGN. Mexico: Mexico has been added to our Board of Directors. José Angel González Vargas is the new National Representative for Mexico. Jose Angel is a member of the Mexican YGN:” Asociación de Jóvenes por la Energía Nuclear en México (AJENM)”. Tanzania: IYNC Board of Directors approved the request from Kenneth Renny Simba from the Tanzania Atomic Energy Commission to be the new Tanzanian National Representative.
New IYNC website: As you have seen, new implementations had been implemented on the IYNC website. A new design for the main page, a map with all the IYNC on the world (check yours!) a new Facebook page (are you already in?) and a new presentation of all the items of past and new congresses! Anyway, we're open to new ideas or suggestions. Just email them to email@example.com.
IYNC Bulletin 5
IYNC National activity Grant. Slovenian YGN has been awarded with an IYNC grant to attend the ‘Student Arena’ that was held from 18-20 October 2011 in Ljubljana, Slovenia. The ‘Student Arena’ is an annual national fair where different universities, institutions and utilities, both research and industrial, present career opportunities for students. The YGN of Nuclear Society of Slovenia is already a traditional participant at the fair.
IYNC international project Grant: The Dutch Young Generation and Belgium Young Generation made an excursion to the Chernobyl site. Each network has 10 participants (20 total). The visit lasted for 3 days and is sponsored by the Netherlands Nuclear society as well as the Belgium Nuclear Society. The Young Generation networks from each country could exchange ideas and learn from each other’s experience. This will help in future national and international projects
Section 3: IYNC Network News
Youth Future Nuclear IYNC 2012: Update IYNC2012 Executive Committee held the third Ex-Com meeting in London in order to organize the next IYNC Conference in Charlotte. The main purpose of these meetings is to gather in the same place and at the same time all the IYNC conference organization: International chairs, Technical Programme chairs, and the local organization. In addition, promoting the IYNC mission and helping local YGNs is an advisable goal to achieve parallel to Ex-Com meeting. In this case, the fundraising strategy was reviewed, the budget was agreed and the workshop schedule was showed.
Ex-Com Meeting participants in the Ernst & Young Building in London. New Professional Development Content Chair: We are glad to present Jimmy Hennen as the new Professional Development Content Chair. Welcome Jimmy! We would like to thank also Erin West for her contributions. Call for summaries: The call for summaries has its deadline on 15th January. Hope we can see most of your papers there. New sponsors for IYNC 2012: IYNC wants to thank all the new sponsors that believe in this project. The new sponsors are Duke Energy (Diamond ), Constellation, Entergy and Nuclear Energy Institute (Platinum), TVA and PG&E (Gold), Fluor, Edgen Murray and URENCO (Silver), EPRI, FirstEnergy and Bechtel (Bronze) and MPR Associates and GNS as contributors.
IYNC Bulletin 6
Section 4: IYNC2012 Update
About the IYNC Network •Provide a platform for professional networking •Transfer knowledge across international boundaries Network
•Promote further peaceful uses of nuclear science and technology
Contact Wim Uyttenhove firstname.lastname@example.org Programme Chair Craig Albers email@example.com General Co-Chair Miguel Millan firstname.lastname@example.org IYNC President
For the Latest Information •Develop new approaches to communicate about nuclear power •Transfer knowledge from the current nuclear generation to the next
IYNC has held six successful conferences around the globe: in Slovakia (2000), South Korea (2002), Canada (2004), Sweden/Finland (2006), Switzerland (2008), South Africa (2010). The recent Congress in Cape Town attracted over 250 professionals from 26 countries!
Youth Nuclear Future International Youth Nuclear Congress 2012 Charlotte, USA August 5-11
Final call for summaries
check our website
http://www.iync.org Strategic Planning: Opportunity for Innovative Growth
Co-hosted by: North American Young Generation in Nuclear
IYNC 2012 Already a tradition in the nuclear field, IYNC 2012 conference will offer the opportunity to share knowledge, experience, best practices and information about nuclear energy between generations and also between peers. IYNC and NA-YGN are pleased to announce that the summary submission for IYNC 2012 conference is now opened.
Submit your summary now: http://www.iync.org/iync2012/call-for-papers.html All experience levels welcome. No fee to submit your summary.
Important Deadlines for Summaries •January 15, 2012 - Deadline for accepting summaries •March 1, 2012 - Decision made on selected summaries
Wim Uyttenhove email@example.com Programme Chair
Venue The International Youth Nuclear Congress (IYNC) 2012 meeting will be held in Charlotte, North Carolina (US), in August 5-11, 2012. The congress will take place in the Westin Charlotte hotel.
Aug 5 Sun
Aug 6 Mond
Aug 7 Tues
Keynote Address Morning
Registration Plenary Session
Aug 8 Wed
Aug 9 Thurs
Technical Sessions & Workshops
Technical Sessions& Workshops
Technical Sessions & Workshops
Closure and Award Session
IYNC BoD Meeting
Networking Networking Event or Free Event or Free Time Time
Proposed Technical Tracks •Track 1: Strategic Planning & Professional Development •Track 2: Plant Design, Construction, Operation, Maintenance & Decommissioning •Track 3: Nuclear Fuel Cycle & Waste Management •Track 4: Nuclear Politics, Economics & Human Resources •Track 5: Nuclear Safety, Radiation Protection and Shielding •Track 6: Advanced Nuclear Systems •Track 7: Radiation Science, Medical Applications & Non Base-load Nuclear Applications •Track 8: Reactor Physics •Track 9: Thermal Hydraulics & Fluids •Track 10: Materials Science & Technology •Track 11: Young Generation Unique Best Practices In addition to the comprehensive technical program, a set of interactive unique workshops will be organized in both technical and non-technical domains. Also social and cultural events are arranged. These activities will allow delegates to network and to experience the unique culture of the American Southeast.
Aug 10 Frid
Aug 11 Sat
Team Building or Cultural Event
Registration Deadline •Early Registration March 1st •Late Registration July 13th •Registration Close July 20th
Technical Tours The technical program will include visits to nuclear power plants, facilities for medical applications and fuel fabrication plants.
Accommodation The official hotel of IYNC2012 is the Westin Charlotte. A discounted rate of US$ 139.00 /night will be available for conference attendees. Details for making room reservations will be available in early 2012.
IYNC is a network of a new generation of professionals to: develop new approaches to communicate benefits of nuclear power, as part of a balanced energy mix; promote further peaceful use of nuclear science and technology for the welfare of mankind; and transfer knowledge from the current generation of leading scientists to the next generation. IYNC has held six successful congresses around the globe - with delegates convening in Slovakia (2000), South Korea (2002), Canada (2004), Sweden/Finland (2006), Switzerland (2008), and South Africa (2010). The recent congress in Cape Town attracted over 300 professionals from more than 30 countries! In conjunction with an outstanding technical programme and professional development workshops, the national representatives took important steps at IYNC 2004 to ensure the sustainability of the organization by adopting bylaws and electing officers and a Board of Directors. The IYNC network now has representatives on six continents and continues to seek out topics and activities of particular important to the future of the nuclear industry. Through their continued involvement with IYNC these individuals and young generation groups share information, ideas, and build lasting professional relationships
For more information please contact: Igor VUKOVIĆ Corporate Sponsorship Chair University of Zagreb Faculty of Electrical Eng. and Computing (FER) Unska 3, HR-10000 Zagreb, Croatia Phone: +385.1.6129.894 Fax: +385.1.6129.890 Mobile: +385.99.7330.414 E-mail: firstname.lastname@example.org Skype ID: ivukovic
INTERNATIONAL YOUTH NUCLEAR CONGRESS 2012
or Christine CSIZMADIA Local Sponsorship Chair Nuclear Energy Institute (NEI) 1776 I Street NW, Suite 400 Washington, DC 20006, USA Phone: +1.202.739.8033 Fax: +1.202.533.0160 Mobile: +1.202.352.3489 E-mail: email@example.com Skype ID: cmc.nei.org
August 5-11, 2012 Charlotte, NC, USA YOUTH, FUTURE, NUCLEAR
Opportunity For the latest information check our website at www.iync.org
for Innovative Growth
Or contact our General Co-Chairs: Miguel Angel Millan Lopez: firstname.lastname@example.org Craig Albers: email@example.com
IYNC 2012 August 5-11, 2012 Charlotte, NC, USA IYNC 2012 will be held in Charlotte, North Carolina, USA, August 5-11, 2012 with technical excursions to nuclear facilities and social programme. In the spirit of a volunteer organization, we are seeking corporate and organizational sponsors who believe in the future of the nuclear industry and in the potential of the next generation.
Examples Available for Sponsorship
DIAMOND ($50,000 and above) Sponsor recognition at the Premium, Major and Significant Congress events Invitation to address the participants at the Welcome Reception (10 min) Official sponsor of Farewell Dinner Preferred placing of logo on all Congress materials Advertising space at the IYNC Congress-Centre Option to include promotional item in participant kits (conference bags) Preferred listing on web site and link to home page Recognition in Congress materials
Farewell Dinner (Thursday) Welcome Reception (Sunday)
PLATINUM ($30,000 to $49,999) Sponsor recognition at the Premium and Major Congress events Preferred placing of logo on all Congress materials Option to include promotional item in participant kits (conference bags) Preferred listing on web site and link to home page Recognition in Congress materials
Cultural Event 1 (Monday) Cultural Event 2 (Tuesday)
GOLD ($15,000 to $29,999) Sponsor recognition at the Major and Significant Congress event Placing of logo on all Congress materials Option to include promotional item in participant kits (conference bags) Listing on web site and link to home page Recognition in Congress materials
There are five levels of sponsorship: contributor, bronze, silver, gold and platinum, with an increasing level of benefits to the sponsors. We will give your organization the recognition you deserve!
Welcome Reception (Sunday) Lunch with Speaker (Monday) Technical Tours including Lunch Plenary and Award Session Scholarship for participants from developing countries
SILVER ($7,000 to $14,999) Sponsor recognition at the Significant Congress event Advertising space at the IYNC Congress Centre Option to include promotional item in participant kits (conference bags) Listing on web site and link to home page Recognition in Congress materials
6 Technical Sessions Tech. Program Poster Exhibit Luncheon Technical Tours including Lunch IYNC Delegates Meeting IYNC Games
BRONZE ($2,000 to $6,999) Sponsor recognition at other Congress events and in Congress materials Option to include promotional item in participant kits (conference bags) Listing on web site and link to home page
CONTRIBUTOR ($500 to $1,999)
Opportunity for Innovative Growth
Listing on web site and link to home page Recognition in Congress materials
Coffee Breaks Paper and/or Poster Awards IYNC Delegates Meeting
Youth Future Nuclear Section 5: Country reports 1.1
Belgium Nuclear Society - Young Generation Update
Nuclear Power Operations in Japan
Accident of neighborhood aggravated the reliability on NPPs in South Korea
Nuclear Energy in Mexico
Nuclear Power in the Czech Republic.
The nuclear program in Romania in the European context, after Fukushima
IYNC Bulletin 7
Section 5: Country Reports
Youth Future Nuclear Belgium
After the accident at Fukushima plant, the EU member countries have decided to carry out earthquake “stress tests” at all their nuclear plants. Belgium has therefore started the stress tests on its 7 nuclear plants and the planning has been respected so far. Short-term actions have already been taken at the sites of Doel and Tihange which will reinforce the resistance to earthquake, flood or blackout.
As of the end of September 2011, 44 out of 54 commercial nuclear power plants are inactive. 14 plants were damaged by 3.11 earthquake and tsunami and were shut down, including TEPCO Fukushima daiichi. The other 30 plants are being shut for periodic inspection or request by the former prime minister (Hamaoka’s 3 plants), and remain off-line until permission is given to restart. Nuclear operators are implementing stress tests of their nuclear power plants and the results will be reviewed by Japanese regulatory authorities. The government said it will promote to restart the plants after ascertaining their safety with the results and winning the consent of the local governments. However, it is unclear due to the public mistrust against nuclear operators and regulatory authorities.
In this context, the BNS-YG (Belgian Nuclear Society – Young Generation) has organized an evening lecture called “Seismic level and structural design of NPPs in Belgium” in September. Professor Thierry Camelbeeck (ORB-KOB) and Mr. Ali Djaoudi (GDF-Suez, Tractebel Engineering), two specialists of seismic analysis were invited to present their job and their knowledge of the seismic activity and its consequences in Belgium. BNS-YG has also continued to interview personalities of the nuclear sector for its website (www.bnsorg.be/yg) such as Luc Geraets (VP Nuclear Activities Division, GDFSuez) and Vincent Massaut (Head of Fusion Research, SCKCEN) who explained with enthusiasm the status of the research on fusion in Belgium and in the world. In the future, BNS-YG will organize a visit of the Tihange NPP and its “Yes-I-Do!” event, in order to discover more about a master-after-master program in nuclear engineering provided by the Belgian Nuclear higher Education Network (BNEN). Finally, BNS-YG is preparing its annual Thesis Contest, a contest for the best final year's thesis of each academic year, organized since 2004 in order to encourage young people to enter the fascinating world nuclear science.
The restoration work on TEPCO Fukushima daiichi nuclear power station is in steady progress. TEPCO and the government are aiming to achieve the “Cold Shutdown Condition” by the end of this year, which is a condition that the temperature of RPV bottom is below 100 degrees Celsius, release of radioactive materials from PCV is under control, and public radiation exposure by additional release is significantly held down. Now they have succeeded in lowering the RPV bottom temperature below 100 degrees Celsius in all unit-1, 2 and 3. The construction and planning of new nuclear power plants are halted after the nuclear accident. In the mid- to longterm outlook, the prime minister stated that Japan must aim to reduce its reliance on nuclear power. Now the government is making revisions of the Basic Energy Plan and Framework for Nuclear Energy Policy. After the nuclear accident, the public perception for nuclear power is becoming negative. According to the latest poll, while 40 % remain for the promotion or sustainment of nuclear power, more than 50% are for the reduction or abolition of nuclear power.
IYNC Bulletin 8
Section 5: Country Reports
Youth Future Nuclear South Korea
South Korea has achieved a remarkable growth in nuclear industries since the commercial operation of Kori Unit 1 in 1978. Currently Korea has a total of 21 commercial facilities in operation, among them 17 PWRs and 4 CANDUs, and seven more NPPs are under construction. The country’s oldest nuclear reactor met its initial lifespan of 30 years in 2007, but after passing the authorized safety checks, it was permitted to resume its operations for another 10 years. Korean government has strong willingness to foster the nuclear energy as a crucial strategy of “Low-Carbon Green Growth” national vision. Today the nuclear energy provides 31% of nation’s electricity, and South Korea is set to become a major world nuclear energy country exporting nuclear technologies. The government plans to construct 14 more by 2024 to provide almost half of the nation’s electricity from nuclear energy.
In 1956 the National Commission for Nuclear Energy (CNEN) was established in Mexico, which was in charge of all nuclear activities in the country, except the use of radioisotopes and the generation of electric power. At the other hand, The Federal Electricity Commission (CFE), a state-owned electricity company, was assigned the role of produce energy using nuclear reactors.
However, an accident occurred at the adjacent neighborhood devastated the public acceptance on the NPPs. Many people were anxious about the exposure to the radiation released by the Fukushima nuclear accidents on account of close geographical location. Not only the favorable awareness resulted from winning the UAE nuclear deal have shrunk significantly, but also the indefinite anxiety that the same accident is likely to occur at the domestic NPPs has widely spread. Some even insists that we reconsider the planned construction and withdraw the continuous extension of nuclear power. As post-Fukushima actions, a large-scale inspection on the earthquake-resistance and tsunami safeguard of nuclear facilities has been performed. Moreover, the protection mechanisms against the station blackout and hydrogen removal equipment are specially improved. Nuclear society is struggling to enhance the nation’s comprehension and public acceptance for nuclear. Still, in Korea, nuclear power generation is a non-discardable provider of future energy. .
IYNC Bulletin 9
Preliminary investigations to identify potential sites for NPPs with a capacity of around 600 MWe were begun in 1966 by CNEN and CFE. In 1976 construction began at Laguna Verde with two 654 MWe General Electric boiling-water reactors (BWRs). The plant is located in coast of the Gulf of Mexico, in the State of Veracruz, Mexico. It produces about 5% of the country's electrical energy. Unit-1 started its commercial operation on July 1990 and Unit-2 on April 1995. With approval from the CNSNS, the reactors were uprated progressively by 138 MWe each from 2008 to January 2011. As a first step, 11.6 MWe uprates to both units were achieved in 2007 through better flow control. In February 2011 Iberdrola announced that both units were operating at 820 MWe gross, about 800 MWe net, a 20% increase from the previous 665.5 MWe net. On the other hand, CNEN was later transformed into the National Institute on Nuclear Energy (INEN), which in turn was split in 1979 into the National Institute of Nuclear Research (ININ) and the National Commission on Nuclear Safety and Safeguards (CNSNS). ININ is the main nuclear research organization in Mexico while CNSNS is the nuclear regulatory body. ININ have operated a 1 MW TRIGA MARKIII Reactor for training and radioisotopes production since 1968, currently this reactor is in process of conversion from the HEU fuel (High Enrichment Uranium) to the LEU fuel (Low Enrichment Uranium).
Section 5: Country Reports
Youth Future Nuclear Spain
In Spain the nuclear fleet, composed by eight reactors in six different sites, provides approximately 20% of the country´s consumed electricity, with less than 8% of the total installed power in the country´s generation park.
In Sri Lanka the main objective of YNSS is to create awareness on “Peaceful Applications of Nuclear Technology & Nuclear power Generation” among A/L students and to the Teachers and Community in a realistic manner.
In 2010 three of the licenses were renewed by the Spanish Government: Almaraz I, Almaraz II and Vandellos II. However, there is one Spanish nuclear power plant, Santa María de Garoña, which is probably going to be shutdown in 2013.
These kinds of Programmes help to demonstrate the real situation, which happened in “Fukushima Daiichi Nuclear Incident” on 11th March 2011.
In 2006, they applied for the renewal of its operating license for a new ten-year period. The application was accompanied by a series of studies and analysis that justified Garoña´s capacity for long term operation in safe and reliable conditions. The Spanish regulator issued a favorable report in 2009. However, according to the Ministerial Order of July 6th, the Ministry of Industry decided to renew the operating license only until July 2013, declaring the termination of activities at the plant on that date. Jóvenes Nucleares wanted to support the efforts made trying to have the long term operation for 10 additional years and we participated in different activities, like “II Nuclear Games” with people from all over Spain. A team of 10 people played futsal and run in the race to support this plant´s continuity.
In addition, YNSS strongly believe that the Seminar/Exhibitions will help to improve the knowledge of A/L students on “Matter & Radiation”, as per the syllabus of Physics in Sri Lankan Education System.
Demonstration of Secondary Standard Dosimetry Laboratory (SSDL) Laboratory, Atomic Energy Authority, Sri Lanka to the Advanced Level Students/ Teachers, who follow Physics & Chemistry .
Team of futsal “Jóvenes Nucleares”
IYNC Bulletin 10
Section 5: Country Reports
Youth Future Nuclear SWEDEN
Final disposal in Sweden
In Sweden there are ten operating nuclear reactors in three different sites – Forsmark, Ringhals and Oskarshamn. The two reactors in Barsebäck were shut down in 1999 and 2005 due to political decisions and will be decommissioned in the upcoming years.
In March SKB (Swedish Nuclear Fuel and Waste Management Co) applied to build a final repository for spent nuclear fuel and an encapsulation plant. The spent fuel will be placed in copper canisters with ductile iron inserts and then placed in tunnels in a depth of about 450 meters in the rock.
The Swedish government has however decided that the old nuclear reactors can be replaced with new reactors, but it is only allowed to have in total ten operating reactors in Sweden. Todays reactors produce about half of the Swedish electricity.
One of the most important parts of these applications is the safety procedures during operation of the Nuclear Fuel Repository and its long-term safety after the repository has been closed and sealed.
As of Friday the 23rd of September, Sweden proudly presents the world’s largest BWR reactor, Oskarshamn 3. The power uprated reactor operates now at 129% which equals 1450 MW electric power (3900 MWth).
An illustration how the final repository for spent nuclear fuel may look like. Source:SKB, Illustrator: LAJ illustration In the very best scenario the Spent Fuel Repository and encapsulation plant will start in 2015.
Two of the reactors in Oskarshamn, O1 and O2. Source: okg.se
Upcoming events in Young Generation Sweden In October there will be a seminar arranged by KSU (Nuclear Training and Safety Center) and Studsvik Nuclear. The seminar will contain one day of study visits and seminars and one day “Unconferense”, where the participants themselves will present different topics in several parallel sessions.
Public opinions The public opinions in Sweden have not changed much since the accident in Fukushima. There is still a large majority in Sweden who is positive to the nuclear industry.
IYNC Bulletin 11
Section 5: Country Reports
Youth Future Nuclear Czech Republic Six Russian-originated, Czech-supplied VVER reactors are operated in the Czech Republic: two VVER-1000, V320 at Temelin NPP in South Bohemia and four VVER440, V213 at Dukovany NPP in South Morava. With installed power close to 4000 MW and generation capacity close to 28 TWh per year both power plants cover about one third of electricity production in the Czech Republic and both owner (the only Czech nuclear utility CEZ) and governmental authorities are considering expansion of Czech nuclear fleet. The expansion of Temelin NPP is of highest priority as CEZ recently prepares public tender for delivery for two more 1000-1600 MW units on ground of formerly planned four 1000 MW units Temelin plant. Dukovany NPP is also expected to be expanded, most likely with one 1000 MW unit, but surely not earlier then Temelin NPP expansion is over.
Czech Republic has decent nuclear R&D, with several research institutions on field of nuclear power. The most well-known nuclear R&D centre is situated in Řež, north of Prague, where two research reactors are operated. Smaller school reactor is also operated in Prague district Troja, at premise of Faculty of Nuclear Sciences and Physical Engineering. Long-time public acceptance of nuclear energy is one of the highest in EU27; almost two thirds of population supports further development of nuclear energy in Czech Republic.
Both Temelin and Dukovany NPPs undergo power uprates program: Dukovany increased installed power from 4x440 MW to 2x460+2x500 MW and aims for 4x500 MW by 2012, while Temelin NPP proceeds with 2010-started project of further exploitation of technical reserves which should increase installed power by 4% on each unit. Life extensions programs are also implemented on both NPPs; license extension for 10 more years was issued for all units at Dukovany NPP, expanding operation license from 20 to 30 years with option on further expansion. In 2010, Temelin NPP Unit 1’s license was expanded from 10 years to 20 years. Czech Republic is mostly the operator of nuclear power plants, even though Czech-based companies delivered nuclear technology components for many East European VVER reactors in last century. Strong technological, nuclear-related industry background is still available, but low demand on VVER new-builds threatens to put Czech Republic in “consumer-only” position.
IYNC Bulletin 12
Section 5: Country Reports
Youth Future Nuclear The nuclear program in Romania in the European context, after Fukushima. The European context has changed after the events at Fukushima power plant in March 2011. At the time of the accident, many spoke about the renaissance of the nuclear energy and about its role in ensuring energy sufficiency and reducing greenhouse gas emissions according to the 20-20-20 policy that the Nuclear Commission has enforced. When the accident happened, Europe had 4 nuclear reactors under construction (in Finland, France and Slovenia) and an impressive number of reactors were planned: •
Bulgaria: two new units at Belene and Kozlodui
The Czech Republic: received offers for two units at Temelin
Switzerland: Resun project
Finland: two new units planned until 2010 (TVO & Fennovoima)
France: second EPR to be commissioned until 2017 (EdF/Penly)
Italy: at least 4 EPRs until 2020
Lithuania: a new unit planned at Ignalina/ Visaginas
Netherlands: a new unit planned at Borssele, starting 2015
Poland: plans to build the first NPP until 2022 (site identified at Zarnowiec)
United Kingdom: 8 identified sites, the first unit in 2018
Romania: two new units to be build until 2020 (Cernavoda)
Slovenia: considers a second unit at Krško
Sweden: considers new nuclear power plants
Hungary: the Government wants to build two new units until 2025 (Pacs)
After the events at Fukushima, the reaction of European countries was a moderate one despite the evident opposition of Germany. Countries like France have stated their support for nuclear energy. Germany was the only nuclear country that took a radical decision under the Merkel Government at the pressure of the public, to shutdown 7 nuclear units which have been in operation since before 1980 and to close down the remaining units until 2020-2022. One can easily notice the difference in reactions between European countries, as regard to the future of nuclear power. 13 European states have not changed their nuclear policy which demonstrates stability and commitment towards nuclear. These countries are: Belgium, the Czech Republic, Hungary, Finland, France, Lithuania, the Netherlands, Poland, Slovakia and Great Britain. In the case of Belgium, there has been a decision to extend the life of the power plants until the publication of the results of the stress tests requested by the European Commission.
The position of Romania was a balanced one, focusing on the continuation of the nuclear program paralleled by the start of a wide nuclear safety reevaluation process.
IYNC Bulletin 13
Section 5: Country Reports
Youth Future Nuclear As per a Government decision, the energy strategy in Romania foresees the construction of Cernavoda NPP Units 3 and 4, which are currently in a pre-project phase. The project is being developed by a project company formed by ENEL Italy, Arcelor Mittal and SN Nuclearelectrica SA – the site owner and operator of Cernavoda NPP Units 1 and 2. After the departure of some investors from the project, due to the economic crisis, the Romanian state has lauched the international procedure to select new investors to the team. Bounding offers are expected until December 15th. Cernavoda NPP is currently undergoing the stress tests, following that at the end of October a final report will be submitted to the National Regulatory Body, in order to be presented at the International Atomic Energy Agency in Vienna, next year. As regard to the technology involved in the new build in Romania and also in the existing one, this country represents an „island” in Europe, as it uses a CANDU 6 type reactor, developed by the Canadian company AECL. The sitting of Cernavoda NPP took into consideration complex studies regarding seismic and also flooding risks. In Romania, the occurrence of an earthquake the size and magnitude of the one that happened in Japan is very unlikely, due to the seismic history of the location where the maximum range of earthquakes was between 7 and 7.5 on the Richter scale. Cernavoda NPP was designed to withstand ground movement of 0.2 G, at the maximum frequency of 1 in 1000 years, which corresponds to a size 8 quake on the Richter scale. In case of earthquake, the power plant’s shut down systems intervene, ensuring the following basic functions: -
Reactor shut down
Cooling of the active zone
Monitoring of all nuclear safety parameters.
IYNC Bulletin 14
Section 5: Country Reports
Youth Future Nuclear Future Events ATOMEX 2011 6-8 December Moscow, Russia, World Trade Center The Russian Atomic Forum ROSATOM, with the sponsorship of ENS announces the organization of the the III International Forum of Nuclear Industry Suppliers, to be held in Moscow in December 2011. The Forum is held to attract new suppliers of products and services required for construction of nuclear facilities and for expansion of interaction with existing ones. Today ROSATOM is implementing a large-scale program of building new reactors to Russian technologies both in Russia and abroad. This constitutes a massive order of the equipment and service orders for vendors in power machine engineering, construction, installation, machinery, and building materials. The Forum will frame an international exhibition and conference. The Forum program includes a walkdown of displays by representatives of customers, technical specialists, designers, operating personnel of major organizations of the industry, including nuclear power plants. At the same time, attending the Conference, the suppliers will have a rare opportunity of getting specialized information, expand their contacts as well as to focus their target audience on products and services provided by your company. Traditionally, the Forum participants are Russian nuclear industry companies, such as Atomstroyexport, Atomenergoproekt (Moscow), Atomenergoproekt (St. Petersburg), Fuel Company TVEL, Atomenergomash etc. The event is organized by Atomexpo LLC and partnered by the State Atomic Energy Corporation Rosatom (Russia). Deadline for registration:November 15th _________________
TopSafe 2012 In view of the on-going discussions and initiatives that have been taken over the last months the European Nuclear Society (ENS) decided organising the next edition of this topical conference from 22 â€“ 26 April 2012 in Helsinki, Finland. TopSafe 2012 provides a forum for addressing the current status and future perspectives with regards to safety at nuclear installations worldwide.
IYNC Bulletin 15
Section 6: Future Events
Youth Future Nuclear TopSafe 2012 will focus on three main subjects:
Safety and related analyses in operating nuclear power plants and other nuclear installations
Safety and Risk Assessment Trends in nuclear safety for existing and future installations
Attendance The conference is directed at a broad range of experts in the area of nuclear safety, including professionals from the different disciplines involved in the safety of nuclear power plants, fuel cycle installations and research reactors. It is aimed at professionals coming from the research organisations, universities, vendors, operators, regulatory bodies as well as policy makers. Top level representatives of the Countries that are constructing new nuclear power plants are invited. Regulators of all individual Countries with nuclear programme are expected to contribute the Conference. Those who wish to participate should upload their contributions by 31 December 2012 at the web address: http://www.euronuclear.org/events/topsafe/topsafe2012/index.htm
Public Information Material Exchange Conference – PIME 2012 PIME is the single conference dedicated to the communication and public relations activities in the nuclear field and it represents the meeting place of the specialists ranging from advertising companies involved with nuclear power plants to academia, and decision makers. PIME represents a great opportunity for any nuclear facility to present their achievements in the field of engaging the public in ingenious and efficient ways, to draw knowledge from the experience of others and to debate issues such as public acceptance, communication strategies and more in the frame of interactive workshops. The 2012 edition of PIME will take place during February 12-15, 2012, in Warsaw, Poland, with the support of ENS, IAEA, FORATOM and NEA. PIME also hosts the PIME Award competition dedicated to the best communication and PR campaign developed over the last year. The award celebrates creativity, the efficient use of communication tools, risk management and innovative research techniques put into action in the constant goal of gaining public support for nuclear. In 2011, the award was won by the Belgium Atomic Forum who developed an event dedicated to the young generation in partnership with a famous rock concert. Application for the PIME Award can be submitted until November 30th. The registration for the conference is opened until the event, but accommodation arrangements must be made previous to the conference. The participation fee is 500 E for young generation members. More information at: http://www.euronuclear.org/events/pime/pime2012/index.htm
IYNC Bulletin 16
Section 6: Future Events
Youth Future Nuclear European Research Reactor Conference 2012 In 2012 RRFM, the European Research Reactor Conference will be jointly organised with IGORR, the International Group Operating Research Reactors. This will allow offering engineers and specialized nuclear researchers the chance to focus on the latest technological developments in the field of nuclear research reactors. The conference programme will revolve around a series of Plenary Sessions dedicated to the latest global developments with regards to research reactor technology and management systems, parallel sessions that focused on specific research projects and initiatives. All Key Areas of the Nuclear Fuel Cycle of Research Reactors Innovative methods in research reactor analysis and design Utilization of Research Reactors Medical Application New Research Reactor Projects Research Reactor Operation, Maintenance and Safety Reassessment The conference will take place in Prague, between 18-22 March 2012. Those who wish to submit abstract, can do so until November 18the 2011. The participation fee of YG members in 395 E. More information at: http://www.euronuclear.org/meetings/rrfm2012/index.htm
IYNC Bulletin 17
Section 6: Future Events
Venue ENSTA ParisTech 32 boulevard Victor 75015 PARIS
Public Transportation Porte de Versailles Balard Desnouettes
Registration fee Visits & Conferences
Registration on www.sfenjg.org
Train transportation and accomodations are not included in the registration fees
November 7th - 10th Paris
The SFEN JG is pleased to invite you to the 2011 edition of « Atoms for the Future ». This edition aims at providing a wide overview of the history and issues of the worldwide development of nuclear fuel cycle.
SFEN JG, 5 rue des Morillons 75015 PARIS (firstname.lastname@example.org)
November 7th Visit of CEA - ATALANTE facility in Marcoule
November 9th AM:
•ATALANTE research facility is the largest Copyright CEA
nuclear chemistry hot labs in which is performed the utmost R&D on the nuclear fuel cycle back-end. •With 250 staff, ATALANTE is covering a very wide range of R&D, from the most fundamental researches on actinides and extracting molecules, up to technological development and process validation at a larger scale on actual spent nuclear fuel in shielded cells. CEA Atalante Hot Cells
Opening Session Front End and Back End: strategic, economic and political considerations (AREVA, Georges CAPUS)
AREVA Eurodif Site
Eurodif, an AREVA group subsidiary, has been enriching uranium by gaseous diffusion and meeting the enriched uranium requirements of power generators since 1978. With the Georges Besse II plant, AREVA has chosen a technically and economically proven solution, the centrifuge technology. The Georges Besse II plant is gradually succeeding to the Georges Besse Eurodif plant.
AREVA GBII Site
A short history of La Hague reprocessing facility (AREVA, Jean Pierre GROS)
Mining: ressources, needs, process (DGEC, Ministry of Ecology, Energy, Sustainable Development and Sea)
Fuel from nuclear operator point of view (EDF, Michel PAYS)
Panel Discussion: Securing fuel supply The secure access to fuel supply is a key issue for the development of nuclear industry, especially in embarking countries. The tight links between geopolitics, energy and economy issues will be debated by high level speakers.
scientific issues associated with recycling of actinides.
•The Georges Besse plant operated by
Panel Discussion: Public acceptance on final waste disposal Radioactive wastes are often seen as the chink in the armor of nuclear industry. What are the existing solutions ? What are the different countries’ choice ? How do public feel about this issue ?
•R&D in ATALANTE - Societal and
November 8th Visit of AREVA Tricastin Facilities
Future recycling technology and French strategy on future cycles (CEA)
Waste management (ANDRA, Gérald OUZOUNIAN)
Youth Future Nuclear Students News University of Las Vegas, USA, hosted the Radiochemistry Fuel Cycle Summer School from June 5th through July 15th. This program was intended for undergraduates in chemistry, physics, and nuclear engineering. The aim of the school was to help students understand the basics of the nuclear fuel cycle. 13 students from all across the US participated in this school. Students from Britain visited the Czech Technical University and had the opportunity to operate the VR-1 Nuclear reactor there. Students visited from the UK defense academy conducted experiments under the observation of Czech technical staff. The VR-1 reactors are very similar to Pressurized Water Reactors used on British submarines. The Nuclear Engineering Student Delegation (NESD) is a group of students that meets in Washington D.C., USA every year to discuss issues facing nuclear energy, policy, education and research with the policy makers in the United States. These students voice the concerns and opinions of the nuclear related student population. The first International Nuclear Energy Olympiad was held in Seoul, South Koria from September 26th-30th. This event was hosted by Korea Nuclear Energy Promotion Agency (KONEPA) and was organized by the World Nuclear University (WNU). 10 students from ten countries attended this Olympiad and the developed a plan to gain acceptance of nuclear energy and power in their country. The participating students were from the countries: Canada, India, Japan, South Korea, USA, Russia, Turkey, Malaysia, Romania and Mongolia. The Canadian team won the International Nuclear Energy Olympiad this year. The International School for Nuclear Law had its summer session from August 22nd to September 2nd. This event was hosted at the University of Montpellier, France. The goal of this school is to provide its students an in-depth knowledge of nuclear law including radiological protection, nuclear safety, transport of nuclear materials, etc. This course is for law students and young professionals in the nuclear sector and is hosted every year at the same venue.
From April 28th-29th, American, Chinese and Russian students discussed solutions to nuclear challenges in the Middle East. The students met in Monterery, USA and this event was organized by the James Martin Center for Nonproliferation Studies (CNS) through the Critical Issues Forum program (CIF). This program included student as well as teacher participation. Through this program, students explored how to prevent the spread of nuclear weapons in the Middle East, including establishment of a Middle East nuclear weapon free zone (NWFZ), strengthening International Atomic Energy Agency (IAEA) safeguards, enforcing sanctions, and military action. The F-Bridge Projects aims for the synergy between modeling and experiments for the investigation of nuclear fuels and materials under irradiation. This year, the school met at the Fitzwilliam College, Cambridge (UK) from Monday, September 19th to Friday the 23rd. 40 students from all over the world attended this school and all the students attending the conference brought a poster to present. The International Physicians for the Prevention of Nuclear War (IPPNW) had two student conferences this year: â€˘ Student Physicians for Social Responsibility- USA chapter held a national student meeting at Washington in April 2011 â€˘ The 21st IPPNW European students meeting held in Tallinn, April 21-24 2011. The IPPNW has also planned to organize a bike tour in which 30 anti nuclear war activists will take part and cycle 500 km to Hiroshima where the 20th IPPNW world conference will take place.
IYNC Bulletin 18
Section 7: Student Section
Youth Future Nuclear Technical Papers European Nuclear Young Generation Forum 2010 papers 7.1. ANALYSIS OF THE PRESENCE OF VAPOR IN RESIDUAL HEAT REMOVAL SYSTEM IN MODES 3/4 LOSS-OF-COOLANT ACCIDENT CONDITIONS USING RELAP5 7.2. CHALLENGES AND OPPORTUNITIES ASSOCIATED TO THE ENGINEERING OF THE FUEL FOR THE 3RD NPP IN ARGENTINA.
IYNC Bulletin 19
Section 8: Technical Articles
Youth Future Nuclear Analysis of the Presence of Vapor in Residual Heat Removal System in Modes 3/4 Loss-of-Coolant Accident Conditions using RELAP5 Kerim Mathy, Westinghouse Electric Belgium S.A., Rue de lâ€™ Industrie 43, 1400 Nivelles, Belgium ABSTRACT The Westinghouse Nuclear Safety Advisory Letter NSAL-09-8 investigated the possibility of presence of vapor in Residual Heat Removal (RHR) System in Modes 3/4 Loss-of-Coolant Accident (LOCA) Conditions. This concerns the Westinghouse standard 3-loops plant for which the RHR is the low pressure part of the Safety Injection (SI). In some cases one or both RHR trains may become inoperable for Safety Injection (SI) function. As a response to this letter, Westinghouse Electric Belgium is providing RELAP5 analyzes for Westinghouse Nuclear Steam Supply System (NSSS) European plants to assess the thermal hydraulic behavior of the RHR suction piping system for Emergency Core Cooling System (ECCS) initiation events postulated to occur during startup/shutdown operations. Several concerns including condensation induced water hammer and voiding at the RHR pump have been investigated. As a conclusion, the analysis allowed to define the bounding Hot Leg temperature conditions under which both RHR Trains remain safely operable. These bounding conditions are then implemented by the customer in their Operating Procedures (OPs) to achieve safe operations and successful accident management. 1.
According to the Nuclear Safety Advisory Letter NSAL-09-8 (Ref 1), when the RHR system (Figure 1) is secured from shutdown cooling operation and placed in stand-by for ECCS function, water at the prevailing reactor coolant system (RCS) temperature becomes trapped in the RHR system piping. This trapped fluid may be well in excess of 100Â°C. In the event of a postulated shutdown LOCA (Modes 3/4), the trapped fluid in the ECCS suction lines might flash if the system is called upon to deliver flow in the safety injection mode because it would suddenly be exposed to lower pressure. This pressure can be much lower than the saturation pressure corresponding to the temperature of the fluid previously trapped in the RHR system piping. Vapor formation in this piping has the potential to degrade pump performance and may cause component damage. There is also a potential for condensation induced water hammer (CIWH) in these lines, should water flowing from the refueling water storage tank (RWST) or from the containment sump come in contact with vapor present in the RHR pump suction line. In addition, the issue may not be only limited to the suction side of the RHR pumps. Depending on the lay-out of the RHR system with regard to check valve presence, location, and system elevation relative to the containment sump, the RHR Heat Exchanger and portions of the discharge piping could also be vulnerable to CIWH if the design and alignment permit the fluid in the primary side of the RHR HX to drain (backflow) into the sump during the switchover from injection to recirculation during a LOCA. This would pertain to some plants for postulated small break (SB) LOCA scenarios when the RHR pumps are turned off and not restarted until after alignment to the ECCS sump for recirculation. As a response to this issue, Westinghouse Electric Belgium is providing RELAP5 analysis to investigate the thermal hydraulic behavior of the RHR suction piping system for ECCS initiation events postulated to occur during startup/shutdown operations. These behaviors include the potential for steam intrusion into the RHR pump as well as to create conditions conducive to condensation induced water hammer, both on
IYNC Bulletin 20
Section 8: Technical Articles
Youth Future Nuclear initiation of Refueling Water Storage Tank (RWST) injection as well as during switchover to the sump recirculation mode. This NSAL applies to Westinghouse NSSS in which the RHR system serves as part of the ECCS. The first part of the project characterizes the RHR system and the conditions in which it is operated. The second part deals with the modelization of the RHR system with RELAP5/mod3, including the initial, boundary and time transient conditions of the cases studied. The third and final part is the thermal hydraulic analysis of the RELAP5 model, in which sensitivity studies based on RHR initial temperature are performed to define the limiting temperature at which void transportation to the RHR pump and water hammer wave load magnitude remain under the acceptance criteria, to be defined with the plant engineering staff. 2.
The first objective of the project is to represent the RHR system within its current plant specific conditions to assess whether it is operable or not regarding given safety criteria. The second objective is to lead an investigation on the initial thermal hydraulics conditions of the transient, more precisely the Hot Leg initial temperature, to provide the best conditions for which the RHR system can be operated safely and fulfill its purposes without any risk of damage during a LOCA accident in Mode 3/4. 3.
THE RHR SYSTEM IN MODE 3/4 LOCA CONDITIONS
For Westinghouse NSSS power plants, there are up to 6 operating modes, representing different conditions for the plant. The modes to be considered in this analysis are: -
Mode 3, which is the Hot Standby, RCS average temperature Tavg > 177째C
Mode 4, which is the Hot Shutdown, where the RCS average temperature Tavg satisfies 77째C > Tavg > 93째C (these temperature may be reconsidered from one plant to another)
IYNC Bulletin 21
Section 8: Technical Articles
Youth Future Nuclear
According to NSAL-09-8, the conditions to be considered are the transition from Mode 3 to Mode 4. In Mode 4, one or two trains may be connected to the RCS depending on the Operating Procedures. Water at the temperature of the RCS is flowing through the connected trains, and if Low Head Safety Injection (LHSI) would be required, this hot water would remain trapped in the RHR train as the realignment process is actuated. This defines the initial conditions for these analyzes. If a LOCA occurs, the RHR System is used in ECCS modes to provide cooling of the RCS. In such conditions, the normal path of suction flow is from the RWST until swap over to the containment recirculation sump occurs on reaching the RWST low-low level set point. When the RWST level decreases to this value, the containment sump isolation valve is opened to line up suction from the containment sump and the RWST suction isolation valve is closed. Thereafter, RHR pump suction is taken from the containment sump. Pump discharge flow passes through the RHR Heat Exchanger and then into the RCS loops. Also, during low pump flow conditions, a minimum flow line returns a flow downstream of the Heat Exchanger to the suction header and vertical header from the containment sump/hot leg suction line. 4. RELAP MODEL OF RHR SYSTEM
The aim is to examine in details the RHR system of the NPP with respect to the NSAL-09-8 issues, i.e. the potential flashing of fluids at a high temperature trapped in the hot leg suction line following the isolation of the RHR system during startup/shutdown operations. A model of the RHR suction piping system is developed extending from the sump and RCS Hot Leg suction downstream Hot Leg isolation valves through the pump to a point downstream of the RHR Heat Exchanger. The model includes the minimum flow line as well to capture thermal feedback of cooler water as hot fluid travels toward the RHR pump in the suction piping. A screening evaluation of the RHR system is first performed before building the RELAP5 model. This key step is an opportunity to discuss relevant assumptions that would fairly simplify the model. For example, modeling the Heat Exchanger could be avoided if the layout show it is mounted horizontal, and therefore that there is no risk to drain it by gravity if the RHR pump stops during the transient. After an accurate study of the plant specific layout and piping isometrics of the RHR system, the geometry of the RHR system is nodalized into RELAP5 hydrodynamic components (Figure 2), representing the hydraulic of the system, including pipes, elbows, tee branches, valves and heat structures. Time and boundary conditions are then applied to the system in order to best represent the conditions in which this system is going to be used. Those conditions are mostly provided by the OPs and EOPS. Based on the phenomena described above, the analytical approach needs to provide for the characterization of the following: •
Steam flashing and condensation.
Heat transfer to/from piping structures
Heat transfer to/from the Heat Exchanger.
IYNC Bulletin 22
Section 8: Technical Articles
Youth Future Nuclear •
Ability to characterize inertial responses of piping systems.
Two phase flow.
Water hammer response.
Condensation phenomena occurring at the minimum flow return point.
The RELAP5 computer code has the ability to perform these characterizations. The numerical schemes of RELAP5 are selected regarding the phenomena of concern, and sensitivity studies are performed to evaluate the conservatism of the schemes used regarding specifically this analysis.
Figure 2 RELAP model
After the examination of the EOPs, two main parts can be defined in the transient. Simulating the first part of the computation can take in average 200 seconds in RELAP5. It includes the realignment process followed by the RWST injection phase. When the RHR train is realigned to LHSI mode, it takes suction from the RWST and cold water is injected into the RHR System. This first phase is mostly characterized by RHR
IYNC Bulletin 23
Section 8: Technical Articles
Youth Future Nuclear pump start, the RWST isolation valve opening and the cold leg connection. Depending on how the RWST isolation valve is open, the start-up of the pump usually depressurizes the Hot Leg suction pipe, which creates void as it is where trapped hot water is located. It also creates void directly at the inlet of the pump, depending mostly on the start-up time of the RHR pump. The second part of the computation is simulated to begin around 200 seconds after the start of the transient. It includes the switchover operation to containment sump recirculation. Once the RWST level reaches the low-low level setpoint, the injection path switches from the RWST line to the sump line. This swap over can be done with or without stopping the RHR pump, this actually depends on the plant specific EOPs. Steam located in the Hot Leg suction pipe is pulled back to the containment sump as a counter flow is created from the RWST to the containment sump. This steam pulled by this counter flow is condensed by cold water, which usually rises water hammer concerns. Trips are defined in RELAP5 to simulate those valve and pump manipulations, with the right delays and time sequence. Again, those parameters strongly depend on the plant specific EOPs. 5. VOID TRANSPORTATION AND WATERHAMMER CALCULATION
The following plots were created in several analyzes, and generally show the thermal hydraulic behavior of specific phenomena concerning the RHR trains when such a transient is computed. At the start of the RHR pump (20s) the flow goes from the RWST to the RHR pump. The limiting parameter is usually the void fraction at the pump when it starts up, as it creates a depressurization in the suction line depending on the inertia of the RWST suction piping. The switchover operation (230s) is usually the most limiting part of the analysis, as it makes the pressure of the Hot Leg suction line reach its lowest value during the transient. When the sump is connected to the RHR system, a counter flow can be created to the containment sump while the RWST isolation valve is closing. Then the flow goes from the containment sump to the RHR pump.
IYNC Bulletin 24
Section 8: Technical Articles
Youth Future Nuclear Hot Leg at 110 째C - Mass flow
Mass flow rate (kg/s)
350 250 150
RWST injection flow Sump recirculation flow
50 -50 0
During this switchover operation, the Hot Leg is depressurized to the containment sump pressure; it tends to induce voiding into the RHR pump suction line, which is pulled into the RHR pump suction path. The void reaching the pump is the first limiting criterion. In addition, this void is condensed while traveling into the RHR pump suction path, which often leads to condensation induced water hammer. The water hammer wave load magnitude is the second limiting parameter. Those limiting parameters are bound by physics criteria to be defined with the customer. For the void fraction criterion, a maximum void fraction value of 3% at the pump is recommended in pump handbooks, otherwise the pump performance is affected. For the water hammer magnitude wave load, a piping stress analysis can be realized afterwards, or a really conservative criterion could be preferred. In any case, the limiting criteria are the void fraction at the pump and the water hammer magnitude wave load, so that the initial thermal hydraulics conditions of the problem have to be adjusted not to exceed the criteria. Here is a table showing the impact of reducing the initial Hot Leg temperature of a RHR train on the void fraction encountered at the RHR pump, for a specific NPP.
Hot Leg temperature (째C)
Maximum void fraction at the pump (%) during pump start up (shutdown mode)
Maximum void fraction at the pump (%) during pump start up (start up mode)
Maximum void fraction at the pump (%) during swap over operation
IYNC Bulletin 25
Section 8: Technical Articles
Youth Future Nuclear 115
Table 1 Sensitivity analysis on the initial Hot Leg temperature
The plot below shows that 120°C is not acceptable for the RHR train considered, as there is more than 20 % of steam at the RHR pump. A reduction by 10 °C is required to reduce the void fraction under the criterion of 3 % maximum voiding at the pump.
Hot Leg at 120 °C - Void fraction at the RHR pump 0,3
0,25 0,2 0,15 0,1 0,05
The generalized force equation in one-dimensional form can be resolved for a piping segment bound by two elbows as:
A( z )V dz t
This is the unsteady reaction force caused by the rate of fluid momentum change within the control volume represented by the pipe segment (so-called wave load) and the wave load approaches zero when the flow approaches the steady state condition. RELAP5 employs a two fluid treatment, and with consideration of the vapor components of the flow, this equation becomes:
IYNC Bulletin 26
Section 8: Technical Articles
Youth Future Nuclear Ftot
( f f A ( z )V f g g A ( z )Vg ) dz t
Where, = density, A = flow area, V = velocity, = void fraction, z = distance along piping axis and subscripts f and g refer to liquid and gas phases. Adjusting the initial thermal hydraulic data mostly implies reducing the initial Hot Leg temperature to a value for which the results are acceptable regarding the chosen criteria. Other sensitivity studies are also performed, for example on the RWST water temperature, to make sure of the conservatism of the analysis. As shown below as an example, a 10 °C reduction significantly reduces the water hammer wave load encountered in a RHR piping during the switchover operation. The wave load is greatly reduced when a lower Hot Leg initial temperature is used in the input deck.
Wave load at switchover operation 70000 60000
Wave load (Newton)
50000 40000 pipe 115 - 120°C initial temperature
pipe 115 - flooded weight 20000 pipe 115 - 110°C initial temperature
10000 0 235
SUMMARY AND CONCLUSION
The first objective was to describe the current conditions in which the RHR system would be operated if a LOCA would occur during Mode 3/4. This has been achieved by reviewing and analyzing the OPs/EOPs and RHR system layout, building a RELAP5 model to compute the transient evolution of the RHR system, and assess the potential damages encountered by the system within those conditions. The second objective, given the potential damages encountered in the current operating conditions, was to provide bounding conditions for which the RHR system can be safely operated relatively to two protection
IYNC Bulletin 27
Section 8: Technical Articles
Youth Future Nuclear criteria: limited void fraction at the RHR pump and limited water hammer wave load. It has been achieved by adjusting the initial Hot Leg suction line temperature of the trapped water. These new plant specific conditions are then implemented in the OPs/EOPs. 7.
The author wishes to express his appreciation to all the members of these projects, more precisely to Mehdi Moussaid, Alexandre Neve, Philippe Mezen, Philippe Gauthier and Antoine Rubbers from Safety & System Analysis (SSA) Group, for their outstanding participation related to the NSAL-09-8. In addition, most sincere gratitude is extended to Kevin Ramsden and Jaehyok Lim from Fauske & Associates for their excellent technical contribution to the analyzes. 8.
 Westinghouse Electric Company, NSAL–09–8, 11/03/2009.  RELAP5/MOD3.3 CODE MANUAL VOLUME II: APPENDIX A INPUT REQUIREMENTS, Nuclear Safety Analysis Division, January 2002.  Frederick J. Moody (1990). Introduction to Unsteady Thermofluid Mechanics. John Wiley & Sons  Perry’s chemical engineers’ handbook, 50th edition, Robert H. Perry & Don Green, 1984.  CRANE, Flow of Fluids through valves, fittings and pipes, 2009.  Nuclear Energy Institute (NEI), 2009, NEI Letter APC 09-10.
IYNC Bulletin 28
Section 8: Technical Articles
Youth Future Nuclear Challenges and Opportunities Associated to the Engineering of the Fuel for the 3rd NPP in Argentina S. Castañiza, L. Alvarez 1 Comisión Nacional de Energía Atómica (CNEA). República Argentina
ABSTRACT CNEA (National Atomic Energy Commission) has developed a strategy to perform the engineering activities for the First Core of CNA-2, the 3rd Nuclear Power Plant in Argentina, whose construction was resumed in 2006. The aim of this strategy is to have at CNA-2 a reliable fuel manufactured in accordance with technical documents corresponding to a verified design. CNEA adapted the KWU/Siemens original design for the fabrication in Argentina, taking into account information from the experience of fuel design and fabrication for CNA-1. An extensive involvement of CNEA in the quality assessment process was possible through an active participation in the initial set up of the fuel manufacturing and in the qualification of the special fabrication processes. This involvement also includes on-site inspections and the analysis of manufacturing non-conformities. Fuel reliability is also pursued through extensive structural and thermo-mechanical design verifications. These verifications were performed through calculations and laboratory tests, including a full scale endurance test. An optimization process (on materials, manufacturing processes, fuel design, and operating conditions) based on the manufacturing and operating experience and on the evaluation of the in-pile performance is also foreseeing for the future 9. INTRODUCTION Argentina has two nuclear power plants in operation, one is a CANDU-6 (CNE) and the other is Atucha-1 (CNA-1), a Siemens/KWU PHWR design. Currently it is in its final stage the construction of Atucha-2 (CNA-2). This third reactor was also designed by Siemens/KWU. The construction started in the 80’, halted in the 90´ and was re-launched in 2006. Fuel assemblies for CNE and CNA-1 power plants are entirely manufactured in Argentina2 and over the years their designs have been improved as a result of operational experience, fabrication evolution and technical and economic needs. With the decision of Argentine government to complete CNA-2, CNEA (National Atomic Energy Commission) had the assignment of developing and testing the fuel assembly, and perform the quality assessment of the manufacture. From the beginning CNEA elaborated a strategy to perform the engineering activities for the First Core of CNA-2 in order to have a reliable fuel manufactured in accordance with technical documents corresponding to a verified design. 10.
CNA-2 NUCLEAR POWER PLANT
CNA-2 will supply 692 MWe of net power to the interconnected system of Argentina. It is placed within the line of pressure vessel reactors cooled and moderated with heavy water developed by Siemens/KWU, of which only the MZFR prototype (57 MWe, shut down in 1984) in Germany and CNA-1 (357 MWe) were constructed. 1 2
email@example.com, firstname.lastname@example.org CONUAR, www.conuar.com.ar
IYNC Bulletin 29
Section 8: Technical Articles
Youth Future Nuclear The pressure vessel of CNA-2 has an approximately cylindrical shape of 8.4 meters of diameter and 970 tons and contains 451 fuel assemblies located each one in its own cooling channel. Each fuel assembly together with a filler body and a closure plug form the fuel column. The cooling channels are arranged vertically in a triangular lattice of 272 mm of side within the moderator tank. Figure 1 shows CNA-2 internal components and details of the core. Table 1 summarizes key characteristics of CNA-2 power plant . Each fuel assembly has a diameter of 103 mm, and consists of 37 fuel rods of approximately 5560 mm of length arranged in three concentric circles and a central rod. A tie plate and thirteen spacer grids are used to align and support the fuel rods. Linkage elements connect the tie plate with the coupling unit. Each fuel rod consists essentially of a zircaloy-4 tube containing the stack of fuel pellets, with top and bottom plugs hermetically welded to the tube. The cladding is designed as free standing during the fuel assembly lifetime. Pellets are made of sintered uranium dioxide, (without enrichment). Pellets have dishings at both ends and chamfered edges to accommodate the axial expansion of the pellet stack during irradiation. The CNA-2 fuel assembly design is based on the fuel used in CNA-1, in fact it has the same diameter and the same fuel rod distribution, but the rod diameter is greater in CNA-2. Fuel assembly details are showed in Figure 2 and in Table 2. The fuel columns are removed from the cooling channels during reactor operation through a special fuel loading machine. During normal operation, the reactor needs about 1.8 new fuel assemblies for each day at full power. This nearly continuous recharge with new fuel assemblies is one of the special features of CNA2. Additionally, fuel assemblies partially depleted are relocated toward the center of the core or to the periphery, in order to achieve an adequate distribution of neutron flux and a homogenous extraction burnup. 11.
DOCUMENTATION, MANUFACTURE AND QUALITY ASSESSMENT
CNEA have prepared all the engineering documents, including drawings and specifications, necessary for the manufacture of CNA-2 fuel assembly. These documents are based on the Siemens/KWU original design and in accordance with the CNEA experience of CNA-1 fuel design and operation. The documents were also adapted for the current manufacture capacity of the fuel assembly factory in Argentina. An extensive involvement of CNEA in the quality assessment process was possible through an active participation in the initial set up of the fuel manufacturing and in the qualification of the special fabrication processes . Special processes are those that because of their characteristics, complexity, external regulations or contract requirements have to be qualified to verify that the process satisfies the specified requirements and that the process is stable. Examples of special process qualified by CNEA are UO2 powder fabrication, UO2 pellet fabrication and certain welding processes of key components like fuel rod end caps welding and welding between components of spacer grids . The involvement of CNEA in CNA-2 fuel assembly production also includes on-site inspections and the analysis of manufacturing non-conformities.
IYNC Bulletin 30
Section 8: Technical Articles
Youth Future Nuclear 12.
FUEL DESIGN AND VERIFICATION
FUEL ROD BEHAVIOR As described before CNA-2 core is recharged with about 1.8 new fuel assemblies for each day at full power and the fuel assemblies partially depleted are relocated to obtain the desired neutron flux distribution and extraction burnup. The logistic associated with the refueling and the fuel assembly movement inside the core is called refueling strategy. Once it was defined, power histories of each individual fuel rod were simulated for the initial core and for the equilibrium core . In the work  were selected the power histories with the highest power, burnup and resident time, and jointly with information from the neutronic and thermohydraulic analysis of the whole core, were used to calculate the thermo mechanical performance of the fuel rods in the most conservative conditions, assuring that key parameters like rod internal pressure, pellet temperature, cladding strain due to pellet interaction, etc. are below design limits. SPACER GRID DESIGN CNA-2 fuel rods are supported and aligned by a tie plate and thirteen spacer grids, twelve of them are made from zircaloy-4 sheet by hot and cold drawing, and welding. Figure 3 shows details of the zircaloy-4 spacer grid. The bottom spacer grid is made from Inconel sheet with a very similar design. These spacer grids are in elastic contact with the fuel rods by dimples and a cantilever spring stamped in the zircaloy-4 or Inconel sheets. In each cell of a spacer grid there are four dimples and a spring to hold the fuel rod. The susceptibly of the zircaloy-4 springs to relaxation under high temperature and fast neutron flux conditions was studied by Siemens/KWU in the development of the fuel and later by CNEA. The condition of the springs at end of life was conservatively modeled  to verify that elastic contact is not lost. If it is lost, then quantify the wear damage on the fuel rod surface by an endurance test using the calculated conditions. In these calculations were included both the fuel rod diameter reduction due to irradiation and the spring thermal and irradiation relaxation model. As a result a minimum force or maximum gap for each fuel rod-spring contact was obtained. Due to the axial profile of power along the fuel rods, temperature and fast neutron flux, results depend of the axial position of the spacer grids. Additionally a series of thermal relaxation tests were performed on the spacer grids . ENDURANCE TESTS Information from relaxation calculations of  and from the thermal relaxation tests was used to manufacture a special fuel assembly characterized at end of life conditions, that is with springs relaxed or with gaps between springs and fuel rods. This fuel element was later used in an endurance test. The endurance test was done in the high pressure loop of CNEA. It consists essentially in a fuel channel, exactly the same type of the CNA-2 core, where the fuel element is inserted. The mass flow is approximately the same as in CNA-2 fuel channels, and the pressure and the temperature are representative of in pile conditions. After an end of life endurance test of 1200 hours the fuel assembly was dismantled. Every component of the fuel assembly was inspected. The position of the springs and the remaining forces were measured. The surface of the fuel rods was evaluated and marks were measured and registered. No unallowable fretting marks were found out.
IYNC Bulletin 31
Section 8: Technical Articles
Youth Future Nuclear Additionally, a beginning of life test with a standard fabrication fuel element was performed in the same conditions of mass flow, pressure, temperature and time in the high pressure loop of CNEA. 13.
Based on the manufacturing and operating experience and on the evaluation of the in-pile performance, it is also foreseeing in the future the optimization of materials, manufacturing processes, fuel design, and operating conditions of the CNA-2 fuel. Some activities concerning this have already started. RIGID SPACER GRIDS CNA-1 fuel assemblies are very similar to CNA-2 ones, one of the differences is the larger fuel rod diameter in CNA-2. Other difference is the spacer grids of CNA-1, which are made from a solid bar of zircaloy-4 by water jet cutting and machining. These spacer grids are designed to have solid contact with the fuel rods which are provided with axial bearing pads to perform the interaction with the spacer grids. As CNA-1 uses natural or slightly enriched uranium, the fuel burnup is low enough to not present problems concerning the fuel swelling, cladding growing and interaction between the fuel rods and the spacer grids. The good experience of this type of spacer grid design in the CNA-1 operation and the advance of water jet cutting in precision, cost reduction and scrap efficiency  promote a design of CNA-2 fuel assemblies with rigid spacer grids to replace the spacer grids made from sheet. A prototype of a CNA-2 fuel assembly with rigid spacer grids was tested in a high pressure and temperature loop to verify that the pressure drop is the same as in the original design. Additionally an initial endurance test of 800 hours was performed on the fuel assembly with excellent results on wear over the fuel rods surface . DESIGN OPTIMIZATION Design of CNA-1 fuel assembly, and specifically CNA-1 fuel rods, has been improved over the years. The mass increment program (MASU) for Atucha-1 included several changes in pellet, cladding and rod design that have the aim of increasing the content of uranium for a total of 6.3%. Inspired in this experience and with the same objective, CNEA has studied in  limits and options for a future optimization of CNA-2 fuel assemblies. Since the year 2000 CNA-1 was successfully converted from a natural uranium to slightly enriched uranium (0,85%) . The design of the SEU fuel assemblies has been done by CNEA, and allows a higher burn up (from 6200 to 11400 MWd/tU) and therefore an important reduction on fuel consumption and cost. This trend will possibly be explored in the near future for CNA-2 fuel assemblies too. 14.
With the resumption of CNA-2 construction, CNEA has the challenge to perform the engineering activities for the new fuel, which involves different characteristics and technologies. Completed documentation has been done and fuel verification and testing have been performed. The first core is almost completed and the nuclear commissioning tests for CNA-2 are scheduled for 2011-2012. With plans for new NPPâ€™s in Argentina for the near future (PWR), the experience acquired with CNA-2, will be extremely useful to support and manage this technology shift in the fuel field.
IYNC Bulletin 32
Section 8: Technical Articles
Youth Future Nuclear 15.
Information supplied by Nucleoeléctrica Argentina S.A. www.na-sa.com.ar. V. Trimarco, V. Lorenzo, et al. Application of Concepts of the Qualification of Special Fabrication Processes to the PHWR Fuel Pellets Manufacturing. Technical Meeting on PHWR Fuel Design, Fabrication and Performance. Buenos Aires 2009. L. Lemos, J. Valesi. Zircaloy-4 Spacer grids for CNA-2 Fuel Assembly. Technical Meeting on PHWR Fuel Design, Fabrication and Performance. Buenos Aires 2009. Information supplied by Nucleoeléctrica Argentina S.A S. Castañiza, L. Alvarez. Simulation of CNA-2 Fuel Rod Behavior under Normal Operation. Technical Meeting on PHWR Fuel Design, Fabrication and Performance. Buenos Aires 2009. CNEA. End of Life conditions of CNA-2 Fuel Assembly. In preparation. CNEA. Thermal Relaxation of CNA-2 Spacer Grids. In preparation. S. Valente, L. Lemos, J. Valesi, L. Alvarez. Tie Plates and Spacers for CNA-1 fuel elements made from 100% recycled Zircaloy4. Technical Meeting on PHWR Fuel Design, Fabrication and Performance. Buenos Aires 2009. CNEA. Rigid Spacer Grid Design for CNA-2 Fuel Assembly. In preparation. S. Castañiza, L. Alvarez. Evolutionary Design Studies of PHWR Fuel Rods. Technical Meeting on Advanced Fuel Pellet Materials And Fuel Rod Designs for Water Cooled Reactors. PSI, Switzerland 2009. C. Notari, F. Rey. Uranio Levemente Enriquecido en Atucha-1. http://www.cnea.gov.ar/xxi/revistacnea/3/notari.pdf
     
Table 1: CNA-2 Nuclear Power Plant Data  General Operating Conditions Thermal reactor power Net electric power Total reactor mass flow rate Primary system pressure Coolant channel inlet temperature Mean coolant channel outlet temperature Number of fuel assemblies in the core Number of fuel rods per fuel assembly Fuel rod outer diameter Active fuel rod length Flow cross section in all fuel assemblies Total heat transfer surface of fuel rods Design overpower Mean linear heat rate Maximum linear heat rate Mean heat flux
IYNC Bulletin 33
CNA-1 (1) 1179 335 6334 112.8 261.7 296.1
CNA-2 2160 692 10576 115.0 277.8 314.6
Unit MWth MWe kg/s bar ºC ºC
253 36 (2) 11.90 5.3 1.2805 1805 115 232.0 600.0 62.
451 37 12.90 5.3 1.970 3584 112 232.8 600.0 57.
mm m m2 m2 % W/cm W/cm W/cm2
Section 8: Technical Articles
Youth Future Nuclear Maximum heat flux
(1) After plant commissioning and power uprating (2) Additionally one structural rod per fuel assembly
Table 2: CNA-2 Fuel Assembly design summary  Fuel assembly parameters Number of fuel rods per fuel assembly Length (from the button end to the top of the coupling) Outside diameter (without elastic shoe) Weight of U Number of spacer grids
37 6027.8 mm 107.8 mm
189.11 kg 13 (12 intermediate from Zry-4 and one at the lower end from Inconel 718) Fuel rod parameters
Cladding material Zircaloy-4 Cladding outside diameter 12.90 mm Cladding inside diameter 11.81 mm Number of fuel pellet per fuel rod 379 Fuel column length 5300 mm Initial He pressure 22.5 bar Overall fuel rod length 5566.4 mm Fuel pellets parameters Material Form Density of the pellets Outside diameter Length Enrichment
IYNC Bulletin 34
Uranium dioxide Cylindrical pellets with dishing on both end faces 10.55 g/cm3 11.57 mm 14.00 mm Natural
Section 8: Technical Articles
Youth Future Nuclear Figure 1: CNA-2 Pressure Vessel and Core.
Fig. 2: CNA-2 Fuel Assembly and Fuel Rod
IYNC Bulletin 35
Section 8: Technical Articles
Youth Future Nuclear
Fig. 3: CNA-2 Spacer Grid, details of weld and spring
IYNC Bulletin 36
Section 8: Technical Articles