LAW Radioactive Coupon CO{sub 2} Decontamination Test

May, C.G.

Savannah River Site (S.C.)

关键词: Removal;    Explosive Fracturing;    Storage;    Decontamination;    Specifications;   

DOI  :  10.2172/821204
RP-ID  :  WSRC-TR-2003-00084, Rev. 0 SRT-RPP-2002-00282, Rev. 0
RP-ID  :  AC09-96SR18500
RP-ID  :  821204

美国|英语

来源: UNT Digital Library

【 摘 要 】

The objective of this test is to confirm that CO{sub 2} blasting is capable of effectively removing smearable contamination from the external surface of the Immobilized Low Activity Waste(ILAW) stainless steel container after glass pouring. The smearable contamination level limits specified in the approved test specification are: (1) 367 Bq/m{sup 2} (220 dpm/100 cm{sup 2}) alpha and 3670 Bq/m{sup 2} (2202 dpm/100 cm{sup 2}) beta-gamma (qualification limits); and (2) 100 dpm/100 cm{sup 2} alpha and 1000 dpm/100 cm{sup 2} beta-gamma (design limits). The removal of smearable contamination from radioactively contaminated coupon was demonstrated by varying the following operating parameters: Nozzle standoff distance; Blast air pressure; Pellet rate; and Nozzle travel speed. Coupons were weighed before and after blasting to determine if the CO{sub 2} blasting process removed measurable amounts of surface material from the coupons. High-speed photography was used to capture images of the pellets exiting the blast nozzle as a means of estimating pellet shape and velocity at the blast nozzle. Bleeding tests were performed to determine if fixed contamination remaining on coupons after blasting ''bleeds out'' and measures as smearable contamination under typical storage conditions and times. The bleeding tests consisted of storing blasted coupons with no detectable smearable contamination for a period of 92 days at 95 F. Coupons were removed at 23-day intervals and re-evaluated for smearable contamination. The radioactive coupon blasting tests consisted of four main subtasks: (1) Coupon preparation; (2) CO{sub 2} blasting; (3) High-speed photography; and (4) Bleeding tests.