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Title: SNM holdup assessment of Los Alamos exhaust ducts. Final report

Fissile material holdup in glovebox and fume hood exhaust ducting has been quantified for all Los Alamos duct systems. Gamma-based, nondestructive measurements were used to quantify holdup. The measurements were performed during three measurement campaigns. The first campaign, Phase I, provided foot-by-foot, semiquantitative measurement data on all ducting. These data were used to identify ducting that required more accurate (quantitative) measurement. Of the 280 duct systems receiving Phase I measurements, 262 indicated less than 50 g of fissile holdup and 19 indicated fissile holdup of 50 or more grams. Seven duct systems were measured in a second campaign, called Series 1, Phase II. Holdup estimates on these ducts ranged from 421 g of {sup 235}U in a duct servicing a shut-down uranium-machining facility to 39 g of {sup 239}Pu in a duct servicing an active plutonium-processing facility. Measurements performed in the second campaign proved excessively laborious, so a third campaign was initiated that used more efficient instrumentation at some sacrifice in measurement quality. Holdup estimates for the 12 duct systems measured during this third campaign ranged from 70 g of {sup 235}U in a duct servicing analytical laboratories to 1 g of {sup 235}U and 1 g of {sup 239}Pumore » in a duct carrying exhaust air to a remote filter building. These quantitative holdup estimates support the conclusion made at the completion of the Phase I measurements that only ducts servicing shut-down uranium operations contain about 400 g of fissile holdup. No ventilation ducts at Los Alamos contain sufficient fissile material holdup to present a criticality safety concern.« less
Authors:
Publication Date:
OSTI Identifier:
10126202
Report Number(s):
LA--12700
ON: DE94007116; TRN: 94:004585
DOE Contract Number:
W-7405-ENG-36
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Feb 1994
Research Org:
Los Alamos National Lab., NM (United States)
Sponsoring Org:
USDOE, Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; FISSILE MATERIALS; NONDESTRUCTIVE ANALYSIS; DEPOSITION; GLOVEBOXES; EXHAUST SYSTEMS; FUME HOODS; DUCTS; SURFACE CONTAMINATION; LANL; NUCLEAR FACILITIES; SAFETY ANALYSIS; PROGRESS REPORT; URANIUM 235; PLUTONIUM 239; CRITICALITY; EXPERIMENTAL DATA; RADIATION DETECTORS; STATISTICS 054000; HEALTH AND SAFETY