Can I pay my retirement redeposit from my TSP without penalties or taxes. I am CSRS age 66.

As you are over 59 1/2 you are allowed to take an age-based withdrawal from your TSP if you have not previously taken one. Your age would also insure that there would be no penalties associated with your withdrawal. If you have previously taken an age-based withdrawal, current rules preclude you from taking another. However, with the implementation of the TSP Modernization Act (on 9/15/2019) you will be able to take age-based withdrawals up to 4 times a year.
Taxes are another matter. Withdrawals from your traditional TSP balance are always taxable at your rate for ordinary income. There will be 20% mandatory withholding, so take that into account when requesting your withdrawal.
If you have a Roth balance in your TSP account and the withdrawals will be considered qualified (in your case that would mean that you have had the Roth balance for at least 5 years), there would be no taxes on the portion of your withdrawal that came from your Roth balance.
If you do have both traditional and Roth balances in your account, be aware that, through September 14, 2019, all withdrawals must be proportional between your traditional and Roth balances. Beginning on September 15, 2019, you will be able to specify from which TSP balance you want your withdrawal taken.

Phild, I would like to add, from the retirement side, making a CSRS redeposit is something you should consider based on when the service of the refund occurred. If you have refunded service prior to March 1, 1990, the redeposit is not necessary as this time counts for both eligibility and computation. Since there is no money in the retirement fund to represent that service, OPM calculates an actuarial reduction in your annuity, meaning they spread out what is owed based on the life expectancy tables. To compute the monthly reduction you would divide the refunded amount plus applicable interest by the present value factor for the your attained age in full years at the time of retirement. For example, if you owe $25,000 (principle + applicable interest) and you are age 66, they would reduce your monthly retirement check by $133.05. In this example, you will be 81+ when this money is paid back. Yes, the reduction is for life, but instead of coming up with $25,000, you take the $133.05 per month reduction. And, this does not reduce any survivor benefit entitlement you might elect for an eligible spouse. Now, if your refunded service ended on or after March 1, 1990, that is a different matter because the time will only count to make you eligible to retire however it will NOT be used in calculating your retirement. In your case, you need to have the math run paying and not paying the redeposit to decide which is best for you.