Nonradioactive Air Emissions Notice of Construction use on a portable exhauster on 241-A-101 tank during salt well pumping

摘要

The 241-A-101 tank, a 22.9 meter 3,785,400 liter capacity SST, was constructed from the fourth generation of tank designs, which were capable of holding boiling or self-concentrating waste. Construction features a reinforced concrete shell, dome, and base with a mild steel liner covering the bottom and sidewalls. The tank has a flat bottom with a usable waste depth of approximately 9.4 meters. The tank was put into service in 1956 to store plutonium-uranium extraction (PUREX) high-level waste and organic wash waste. The waste was allowed to self-concentrate up until 1968. Tank sluicing was performed in 1969 and again in 1976 to reduce the amount of strontium and cesium, the two isotopes found to be the main heat generating sources in the tank. In 1978, the tank was reassigned for saltcake storage. The tank was taken out of service in November 1980 and partially isolated in 1982. Salt well pumping is a method used to interim stabilize SSTS. Interim stabilization is commenced once all the liquid above the solids has been removed (primary stabilization). Interim stabilization removes the gravity drainable liquid and the interstitial liquid between the solids from the SST and transfers the liquid to a double-shell tank (DST) or to a staging double-contained receiver tank (DCRT), which is subsequently transferred to a DST. Pumping is accomplished at very low flow rates, 15.1 liters per minute or less. Normally, salt well pumping is performed without the need of an exhauster. However, recent safety evaluations concluded that a minimum exhaust flow rate of 7.1 cubic meters per minute would be required to enhance the safety of the tank. Therefore, active ventilation will be part of this process for the 241-A-101 tank. This document details the Nonradioactive Air Emissions Notice of Construction for the use of a portable exhauster on Tank 241-A-101 during salt well pumping and other routine activities.