Disposing of Flowdocument Page after rendering

Question

            //Create a User Control with a TextBlock
            TextBlock textBlock = new TextBlock();
            textBlock.Text = "Helo";
            UserControl userCOntrol = new UserControl();
            userCOntrol.Content = textBlock;

            //Add the UserControl to a Table
            table.RowGroups[0].Rows[0].Cells[0].Blocks.Add(new Paragraph(new InlineUIContainer(userCOntrol as UIElement)));

            //Add the table to a FlowDocument
            FlowDocument flowDocument = new FlowDocument();
            flowDocument.Blocks.Add(table);

            //Fetch the Visual representation of the page.
            DocumentPage page = ((IDocumentPaginatorSource)flowDocument).DocumentPaginator.GetPage(0);


            //Extract the Visual from the page and add to a Fixed Page
            FixedPage fixedPage = new FixedPage();
            ContainerVisual container = new ContainerVisual();
            container.Children.Add(page.Visual);
            DrawingCanvas canvas= new DrawingCanvas();
            canvas.AddVisual(container);
            fixedPage.Children.Add(canvas);


            //now write the FixedPage to an XPS file
            using (XpsDocument xpsDoc = new XpsDocument("c:\\x.xps", FileAccess.ReadWrite))
            {
                XpsDocumentWriter xpsDw = XpsDocument.CreateXpsDocumentWriter(xpsDoc);
                xpsDw.Write(kj);
            }

The above piece of code releases nothing. Once the flowdocument is paginated and Visual representation of the page fetched, the contents of the flowdocument are refernced by the Visual. so neither Visual gets disposed nor the contents of flowdocument. The above piece of code when executed continuously raised out of memory.

Does anyone know how to release the memory held by all these resources?

Thanks in advance.