after-treatment expenses; cleanup costs
Often used in contexts of nuclear waste disposal or environmental remediation, but can refer to any post-processing or cleanup costs.
The after-treatment expenses for the nuclear power plant are enormous.
Who will bear the cleanup costs for the contaminated land?
処理費用 is a broader term for 'processing costs' or 'treatment costs', while 後処理費用 specifically refers to costs incurred after the main process, often for cleanup or waste treatment.
Compound of 後 (after) + 処理 (treatment, processing) + 費用 (expenses, costs).