4 Dec, 10:19
Grand Slam winners Fiona Coghlan and Nora Stapelton have returned the Women's RBS 6 Nations trophy to Chief Executive John Feehan at the Six Nations offices in Dublin.
The camp will be used as preparation for next year's FIRA-AER European Championship in Toulon.
O'Brien played in the final of this tournament when it was last played in France in 2007.
He helped Ireland defeat England in the semi-final and draw with France in the final.
Ireland Under-18 Clubs Squad:
Andrew Boyle - St. Brigid's; Adam Bratton - City of Derry; Callum Burke - London Wasps; Jack Carty - Buccaneers; Stephen Collins - Ennis; Aaron Conneely - Corinthians; Grant Connon - Carlisle; Jake Considine - Young Munster; Gearoid Crowe - Ennis; Paul Dean - DLSP; Matthew Dever - St. Benedicts; Eddie Downes - Wicklow; Tadhg Furlong - New Ross; Dominic Gallagher - Lisburn; Jonathan Holland - Sunday's Well; Ben Howard Bury - St. Edmunds; Stephen Irvine - Banbridge; Michael Kearney - Clontarf; Lukas Kunz - Ennis; Chris Leathem - Banbridge; David Lynch - Naas; Kieran Marmion - Christ College; Eoin McKeon - Galwegians; Kevin O'Byrne - Highfield; Luke O'Keefe - London Wasps; Ross Osborne - Filton College; Tadhg Power - Sligo; Daniel Qualter - Buccaneers; Stuart Simpson - City of Derry; Conor Smith - Coleraine; John Sutton - New Ross; Sean Wooton - Castlebar
Meanwhile, Ireland Under-18 Schools coach Paul Barr has named a 26-strong squad for their training camp in December.
Ireland Under-18 Schools Squad:
Niall Annett - Methodist College; Shane Buckley - Rockwell College; Conor Carey - Methodist College; Bryan Carroll - Presentation College; Chris Colvin - Royal School Armagh; Ferdia Doherty - Gonzaga College; Harry Doyle - Royal School Armagh; Peter du Toit - Kings Hospital; Alex Kelly - St. Michael's College; Stephen Leckey - Methodist College; Emmett MacMahon - St. Michael's College; Brendan Macken - Blackrock College; Colin Mallon - St. Michael's College; Luke Marshall - Ballymena Academy; Blane McIlroy - Methodist College; James McKinney - Campbell College; Martin Moore - Castleknock College; Jordi Murphy - Blackrock College; Aaron O'Brien - St. Munchin's College; Tiernan O'Halloran - Cistercian C Roscrea; David O'Mahony - Presentation College; Gareth Quinn McDonagh - Crescent CC; Ben Sargent - Crescent CC; Niall Scannell - Presentation College; Aaron Spring - Sligo Grammar School; James Tracy - Newbridge College.