Eddie Ungless

Hopefully not that unique a scenario but I couldn't find clear advice online. I am currently on a well paying internship in the US for four months. My employer is part of the tax withholding scheme (so similar to how it is normally in the UK). I am a UK citizen and so will declare this income and how much tax I have payed when I return to the UK in a self assessment form. I will then pay any additional taxes to the UK. I will apply for a tax refund from the IRS at the end of the US fiscal year as my internship is short and I will be in a much lower tax bracket for the overall year (I normally earn no taxable income as I am a student). This would also be true for the UK. Is this refund from the IRS taxable? Can I also claim a refund from the UK government too for some of the UK taxation?