I want to Please create the MRP order whenever the Main Products scrap orders created and validated. Please note that
if Child MO of MRP is used in MRP those should be created as well. Once created
then validate the MRP orders and its associated Child MO. The below code create main and child mrps when it goes to to_close state it generate error "Produce qty must be positive"
Any body know which step i missed.

    _inherit = 'stock.scrap'

    def action_validate(self):
        res = super(StockScrap, self).action_validate()

        for scrap in self:
            boms = self.env['mrp.bom'].search([('product_tmpl_id', '=', scrap.product_id.product_tmpl_id.id)])
            if not boms:
                raise exceptions.UserError("No Bill of Materials found for the product.")

        mrp_orders_to_confirm = []
        print('.............', boms)

        for scrap in self:
            for bom in boms:
                mrp_order_vals = {
                    'product_id': scrap.product_id.id,
                    'product_qty': scrap.scrap_qty,
                    'product_uom_id': scrap.product_id.uom_id.id,
                    'bom_id': bom.id,

                }
                print(bom.product_id.name, '.................................PRD ID')

                print(mrp_order_vals, '.......................created mrp order')
                mrp_order = self.env['mrp.production'].create(mrp_order_vals)
                mrp_orders_to_confirm.append(mrp_order)
                print(mrp_order, 'MRP ODER ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,')

                for line in bom.bom_line_ids:
                    print(line.product_id.name, ',,,,,,,,,,,,,,,,,,,,,,,,,,,,,PRODUCT NAME')

                    if line.child_bom_id:
                        child_mrp_order_vals = {
                            'product_id': line.product_id.id,
                            'product_qty': scrap.scrap_qty,
                            'product_uom_id': line.product_id.uom_id.id,
                            'bom_id': line.child_bom_id.id,
                            # 'move_raw_ids': [(0, 0, {
                            #     'product_id': line.product_id.id, })]
                        }
                        child_mrp_order = self.env['mrp.production'].create(child_mrp_order_vals)
                        mrp_orders_to_confirm.append(child_mrp_order)

        for mrp_order in mrp_orders_to_confirm:
            mrp_order.action_confirm()

        return res

Thanks 
your reply will be appreciable