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Title: MCNP efficiency calculations of INEEL passive active neutron assay system for simulated TRU waste assays

Abstract

The Idaho National Engineering and Environmental Laboratory Stored Waste Examination Pilot Plant (SWEPP) passive active neutron (PAN) radioassay system is used to certify transuranic (TRU) waste drums in terms of quantifying plutonium and other TRU element activities. Depending on the waste form involved, significant systematic and random errors need quantification in addition to the counting statistics. To determine the total uncertainty of the radioassay results, a statistical sampling and verification approach has been developed. In this approach, the total performance of the PAN nondestructive assay system is simulated using the computer models of the assay system, and the resultant output is compared with the known input to assess the total uncertainty. The supporting steps in performing the uncertainty analysis for the passive assay measurements in particular are as follows: (1) Create simulated waste drums and associated conditions; (2) Simulate measurements to determine the basic counting data that would be produced by the PAN assay system under the conditions specified; and (3) Apply the PAN assay system analysis algorithm to the set of counting data produced by simulating measurements to determine the measured plutonium mass. The validity of this simulation approach was verified by comparing simulated output against results from actualmore » measurements using known plutonium sources and surrogate waste drums. The computer simulation of the PAN system performance uses the Monte Carlo N-Particle (MCNP) Code System to produce a neutron transport calculation for a simulated waste drum. Specifically, the passive system uses the neutron coincidence counting technique, utilizing the spontaneous fission of {sup 240}Pu. MCNP application to the SWEPP PAN assay system uncertainty analysis has been very useful for a variety of waste types contained in 208-{ell} drums measured by a passive radioassay system. The application of MCNP to the active radioassay system is also feasible but is not practiced at this time.« less

Authors:
; ; ;
Publication Date:
Research Org.:
INEEL, Idaho Falls, ID (US)
OSTI Identifier:
20093662
Resource Type:
Journal Article
Journal Name:
Transactions of the American Nuclear Society
Additional Journal Information:
Journal Volume: 82; Conference: 2000 Annual Meeting - American Nuclear Society, San Diego, CA (US), 06/04/2000--06/08/2000; Other Information: PBD: 2000; Journal ID: ISSN 0003-018X
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; ALPHA-BEARING WASTES; IDAHO NATIONAL ENGINEERING LABORATORY; NONDESTRUCTIVE ANALYSIS; RADIOASSAY; DATA COVARIANCES; M CODES; COMPUTERIZED SIMULATION

Citation Formats

Yoon, W Y, Meachum, T R, Blackwood, L G, and Harker, Y D. MCNP efficiency calculations of INEEL passive active neutron assay system for simulated TRU waste assays. United States: N. p., 2000. Web.
Yoon, W Y, Meachum, T R, Blackwood, L G, & Harker, Y D. MCNP efficiency calculations of INEEL passive active neutron assay system for simulated TRU waste assays. United States.
Yoon, W Y, Meachum, T R, Blackwood, L G, and Harker, Y D. Sat . "MCNP efficiency calculations of INEEL passive active neutron assay system for simulated TRU waste assays". United States.
@article{osti_20093662,
title = {MCNP efficiency calculations of INEEL passive active neutron assay system for simulated TRU waste assays},
author = {Yoon, W Y and Meachum, T R and Blackwood, L G and Harker, Y D},
abstractNote = {The Idaho National Engineering and Environmental Laboratory Stored Waste Examination Pilot Plant (SWEPP) passive active neutron (PAN) radioassay system is used to certify transuranic (TRU) waste drums in terms of quantifying plutonium and other TRU element activities. Depending on the waste form involved, significant systematic and random errors need quantification in addition to the counting statistics. To determine the total uncertainty of the radioassay results, a statistical sampling and verification approach has been developed. In this approach, the total performance of the PAN nondestructive assay system is simulated using the computer models of the assay system, and the resultant output is compared with the known input to assess the total uncertainty. The supporting steps in performing the uncertainty analysis for the passive assay measurements in particular are as follows: (1) Create simulated waste drums and associated conditions; (2) Simulate measurements to determine the basic counting data that would be produced by the PAN assay system under the conditions specified; and (3) Apply the PAN assay system analysis algorithm to the set of counting data produced by simulating measurements to determine the measured plutonium mass. The validity of this simulation approach was verified by comparing simulated output against results from actual measurements using known plutonium sources and surrogate waste drums. The computer simulation of the PAN system performance uses the Monte Carlo N-Particle (MCNP) Code System to produce a neutron transport calculation for a simulated waste drum. Specifically, the passive system uses the neutron coincidence counting technique, utilizing the spontaneous fission of {sup 240}Pu. MCNP application to the SWEPP PAN assay system uncertainty analysis has been very useful for a variety of waste types contained in 208-{ell} drums measured by a passive radioassay system. The application of MCNP to the active radioassay system is also feasible but is not practiced at this time.},
doi = {},
journal = {Transactions of the American Nuclear Society},
issn = {0003-018X},
number = ,
volume = 82,
place = {United States},
year = {2000},
month = {7}
}