High-sensitivity measurements for low-level TRU wastes using advanced passive neutron techniques
In recent years, both passive- and active-neutron nondestructive assay (NDA) systems have been used to measure the uranium and plutonium content in 200-{ell} drums. Because of the heterogeneity of the wastes, representative sampling is not possible and NDA methods are preferred over destructive analysis. Active-neutron assay systems are used to measure the fissile isotopes such as {sup 235}U, {sup 23}Pu, and {sup 241}Pu; the isotopic ratios are used to infer the total plutonium content and thus the specific disintegration rate. The active systems include 14-MeV-neutron (DT) generators with delayed-neutron counting, (D,T) generators with the differential die-away technique, and {sup 252}Cf delayed-neutron shufflers. Passive assay systems (for example, segmented gamma-ray scanners)5 have used gamma-ray sessions, while others (for example, passive drum counters) used passive-neutron signals. We have developed a new passive-neutron measurement technique to improve the accuracy and sensitivity of the NDA of plutonium scrap and waste. This new 200-{ell}-drum assay system combines the classical NDA method of counting passive-neutron totals and coincidences from plutonium with the new features of add-a-source'' (AS) and multiplicity counting to improve the accuracy of matrix corrections and statistical techniques that improve the low-level detectability limits. This paper describes the improvements we have made in passive-neutron assay systems and compares the accuracies and detectability limits of passive- and active-neutron assay systems.
- Research Organization:
- Los Alamos National Lab., NM (United States)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 7169807
- Report Number(s):
- LA-UR-92-2563; CONF-920882-2; ON: DE92040385
- Resource Relation:
- Conference: Transuranic waste characterization conference, Pocatello, ID (United States), 10-12 Aug 1992
- Country of Publication:
- United States
- Language:
- English
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Accurate plutonium waste measurements using the {sup 252}Cf add-a- source technique for matrix corrections
Accurate plutonium waste measurements using the sup 252 Cf add-a- source technique for matrix corrections
Related Subjects
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ALPHA-BEARING WASTES
NONDESTRUCTIVE ANALYSIS
LOW-LEVEL RADIOACTIVE WASTES
MEASURING INSTRUMENTS
SENSITIVITY
ACCURACY
CALIBRATION
CALIFORNIUM 252
NUCLEAR MATERIALS MANAGEMENT
PLUTONIUM
URANIUM
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ACTINIDES
ALPHA DECAY RADIOISOTOPES
CALIFORNIUM ISOTOPES
CHEMICAL ANALYSIS
ELEMENTS
EVEN-EVEN NUCLEI
HEAVY NUCLEI
ISOTOPES
MANAGEMENT
MATERIALS
METALS
NUCLEI
RADIOACTIVE MATERIALS
RADIOACTIVE WASTES
RADIOISOTOPES
SPONTANEOUS FISSION RADIOISOTOPES
TRANSURANIUM ELEMENTS
WASTES
YEARS LIVING RADIOISOTOPES
055001* - Nuclear Fuels- Safeguards
Inspection
& Accountability- Technical Aspects
052000 - Nuclear Fuels- Waste Management