(petitioner, contract maintenance laborer who also works maintenance jobs at nuclear power plants and other utility sites, worked only temporary jobs for tax year in issue did not have a principal place of work, but did have his residence as a tax home; petitioner was union member and was contacted for work through the union and at his home; no jobs that petitioner worked lasted more than one year; sometimes, petitioner stayed overnight at job site because of distance from home; substantiated unreimbursed employee business expenses deductible - business miles driven, auto expenses and miscellaneous expenses; accuracy-related penalty imposed for deductions claimed for unsubstantiated expenses).