Dionysius (D Cornelis Groeneveld

Dionysius Cornelis (Dé ) Groeneveld passed away peacefully on November 6 2024  surrounded by his immediate family. Dé was born on December 24, 1941 in Dordrecht, Netherlands. He is survived in Canada by his wife Marilyn, Daughter Erika Ferenczy-Groeneveld, son-in-law Stephan Ferenczy, grandchildren Sascha, Theo and Kaya; and by his siblings in the Netherlands, Nel, Kees, Heleen, Marian, Jos, Jan and Bram. He was predeceased by his brother Gijs.

Dé was born during the Second World War. He graduated from the Dordrecht Technical College in 1962 at the age of twenty. At that time, he had to make a decision: enlist for 18 month (military service was compulsory at that time in the Netherlands), or emigrate to Canada. He chose the latter, worked in St Thomas for a year in various jobs and then applied to the University of Western Ontario (UWO, now referred to as Western University) . Dé was fortunate, UWO had just started an engineering graduate school and were desperately looking for graduate students. They enrolled Dé in a qualifying year (despite his questionable Dutch academic background). That qualifying year proved to be Dé’s most challenging year ever - he worked non-stop for 8 months everyday from 8 am to midnight.  Dé could not have done this but for his roommate, an Indian Student, who was in the same position so they encouraged each-other to keep going. At the end of the year (May 1964) Dé passed the exams in all courses and remembers well how great it felt to finally be able to relax and restart a normal lifestyle. 

Dé obtained his M E. Sc in 1965. While at Western, he met his wife-to-be, Marilyn Plested. On graduating, the idea of continuing his studies appealed to him so he accepted an offer to enter the Ph.D. program at the University of the Witwatersrand (known as Wits), Johannesburg, South Africa . But after 6 months, he decided to discontinue his studies at Wits in favor of a job offer at AECL, Chalk River. Subsequently, after extensive travel in Africa, he joined Marilyn in her travels though Europe.  Marilyn and Dé married on July 3, 1967. Dé has worked at various positions at AECL (including manager for the Thermal hydraulics Branch for several years) while completing his Ph.D. part-time in 1972. He retired in 1999 but continued as a researcher emeritus for the next 15 years. Aside from his commitment to AECL, Dé was also an Adjunct Professor both at the University of Ottawa (for 30+ years!!) and at the University of Toronto. During his 33 year AECL work term he managed to get a one-year's sabbatical from AECL to spend in a French Nuclear  Laboratory (CENG, Grenoble) in 1981-82 and did the same in 1988 in a German  Nuclear Lab (KFK, Karlsruhe).

In parallel Dé served on the Board of North Renfrew Family Services (NRFS) from 2014 (as Board Chair from 2021). He also served on the Boards of Centennial Suites Condo Corporation and Deep River Community Church and was for many years president of the Evergreen Investment Club.  

Dé's favorite hobbies included cycling, canoe or kayak tripping with his family and friends, and X-country skiing and snowshoeing. This year he was kayaking on the Ottawa in March until lung cancer hit him.

Dé is grateful for the great 82 years, enjoyed in good health. He appreciated the excellent support received from Dr. Ceponis during his past year.  A Celebration of Life will be held in Deep River Community Church on Saturday, November 23, 11am followed by a light lunch. No flowers please. Memorial Contributions can be made to NRFS (PO Box 1334) and the Mission fund of Deep River Community Church (PO Box 1149) would be appreciated. His family is so grateful for these past months and how brave he was throughout his battle with cancer.