Title: Introduction Text: A large number of formerly used defense sites (FUDS), installations undergoing base realignment and closure (BRAC), and other military installations have munitions and explosives of concern (MEC) that may contain unexploded ordnance (UXO). Several of these installations are faced with the challenge to remediate these UXO sites to protect human health and the environment. The Naval Explosive Ordnance Disposal Technology Division (NAVEODTECHDIV) has partnered with researchers from Western Kentucky University to develop an innovative field device to detect whether ordnance items found on land are live or inert. This Web Data Sheet discusses the Pulsed Elemental Analysis with Neutrons (PELAN) device, its advantages and limitations, and costs.

Title: MEC Definition Text: This term, which distinguishes specific categories of military munitions that may pose unique explosives safety risks, means: (A) Unexploded Ordnance (UXO) as defined in 10 U.S.C. 2710(e)(9); (B) Discarded military munitions (DMM) as defined in 10 U.S.C. 2710(e)(2) or (C) Munitions constituents (e.g. TNT, RDX) present in high enough concentrations to pose an explosive hazard.

Title: UXO Definition Text: Military munitions that: (A) have been primed, fused, armed, or otherwise prepared for action; (B) have been fired, dropped, launched, projected or placed in such a manner as to constitute a hazard to operations, installations, personnel, or material; and (C) remain unexploded whether by malfunction, design, or any other cause [10 U.S.C. 101(e)(5)].

Title: Need for Technology Text: UXO can range in size from small arms ammunition to bombs weighing more than 2,000 lb. Munitions can be found on the surface or buried underground at depths ranging from a few inches to tens of feet below ground level. UXO items on land generally occur as clusters because they are typically fired or dropped on fixed targets, but also can be found alone. The technologies to detect UXO and discriminate it from other subsurface metallic objects have matured over the past decade. Technologies exist that can differentiate potential UXO from other metallic clutter. For example, ground-penetrating radar is able to discriminate between ordnance and non-ordnance, but cannot confirm whether explosives are still present. Because most ordnance items at training ranges are filled with inert materials such as concrete for target practice, the handling of every piece of ordnance found as "live" increases disposal and remediation costs. Therefore, the ability to discern whether ordnance contains energetic material is of vital importance.

Title: Inert Text: Containing no more than one pound of explosives.

Title: The PELAN System (1 of 2) Text: In response to the deficiency of metallic detectors at indicating the presence of explosive material in ordnance items, the PELAN system was developed by researchers at the University of Western Kentucky. PELAN was first developed in 1999 and has undergone several improve-ments. The current version of the system is designated as the PELAN III. The fourth generation of the PELAN system currently is being developed.

Title: PELAN System (2 of 2) Text: The PELAN system can non-intrusively and non-destructively examine individual ordnance and confirm whether it contains high explosives (HE). The system weighs about 80 lb and contains the neutron generator, the bismuth germanate (BGO) detector, the power and data module, and shielding. A laptop computer is either hard-wired to the system or connected remotely by radio frequency (RF) signal. The operator and the laptop are maintained outside the exclusion zone of 40 feet. Data analysis is performed automatically and a final result of whether explosives are present is reported to the operator.

Title: PELAN Technology Description Text: PELAN works on the premise that explosives contain various elements such as H, C, N, O, etc. in quantities and ratios that differ from other innocuous substances. The PELAN system uses a pulsing deuterium-tritium (d-T) neutron generator. The neutron generator emits 14 MeV neutrons, which initiate several types of nuclear reactions on the object under interrogation. The rays resulting from these reactions are detected by a gamma-ray detector using bismuth germanate scintillators. By using fast neutron reactions, neutron capture reactions, and activation analysis, the elemental composition of elements associated with high explosives can be identified in a continuous mode without physical sampling. The elemental content and its ratios are analyzed to identify the filler materials in ordnance items.

Title: PELAN Pilot Test and Results (1 of 2) Text: In 1995, the Naval Surface Warfare Center-Dahlgren Division, White Oak Laboratory (NSWC-White Oak) was selected for closure on the BRAC IV list. As part of an overall facility environmental cleanup, extensive re-grading was performed. The re-grading operations unearthed numerous ordnance items. The NAVEODTECHDIV was contacted to perform analysis on these items to determine if they were inert or contained energetics prior to the disposal process. The PELAN system was used for risk reduction during this operation to provide an extra level of assurance, beyond visual inspection, that the items were indeed inert. A total of 640 ordnance items were evaluated using the PELAN system during the project. The ordnance items analyzed by the PELAN ranged in size from an 81-mm shell (~2.0 lb of high explosives) to a single Mk 84 bomb (~1000 lb of high explosives).

Title: PELAN Pilot Test and Results (2 of 2) Text: The PELAN was calibrated to each fill type based on the unique pattern of elemental content, which allows for it to be distinctly identified. The parameters for the decision tree are given in Table 1. All the criteria listed in the table must be met before a positive identification is made. For example, high explosives must indicate carbon at greater than 5 counts per second, oxygen at greater than 5 counts per second, and nitrogen at greater than 3.5 counts per second. A summary of the results from the NSWC-White Oak are presented in Table 2. No live ordnance items were identified and most items were determined to be inert empty shells with water content or a shell with a very wet inert material.

Title: Advantages of PELAN System Text: The advantages of the PELAN system are as follows: Economic and safety benefits can be derived by employing the PELAN system to detect the presence of explosive material in UXO. By being able to discriminate ordnance items filled with inert material from those containing high explosives, financial benefits can be achieved by reducing costs associated with the disposal of explosive ordnance. Knowing whether an explosive is present within ordnance and the type of explosive present increases the personal safety of personnel at the site.

Title: Limitations of PELAN System Text: The limitations of the PELAN system are as follows: The primary limitation with the PELAN system is that it generates false negative results when high explosives are present at less than 1 lb in the munition shapes tested. Consequently, items such as fuses (found on many ranges) cannot be effectively analyzed due to the small quantity of explosives present. Although the PELAN system weighs only approximately 80 lb, it must be manually assembled and mounted on a utility vehicle for easy maneuvering. A radiation license must be obtained before the PELAN system could be operated.

Title: Associated Costs Text: The PELAN system is not currently available through a commercial source. However, NAVEOD-TECHDIV has a contract to develop 400 units of the fourth-generation PELAN system in Fiscal Year 2005. It is estimated that the equipment will cost less than $100,000 per PELAN device. The total project cost incurred at NSWC-White Oak was approximately $2,000,000 for the identification, differentiation, and disposal of 1,300 ordnance shapes that weighed 250,000 lbs. As part of this project, 640 shapes were tested with the PELAN and all of the ordnance items were verified inert. Ordnance shapes at sizes greater than 95 mm were demilitarized using a water jet cutting process and ordnance shapes less than 95 mm were destroyed using a Donovan Blast Chamber. The scrap metal was certified inert, demilitarized, and destroyed by a smelter.

Title: Summary Text: Data show that the PELAN system can differentiate ordnance items filled with high explosives from those filled with inert material. The characteristics of the PELAN system can be summarized as follows: Compact and rugged design effective for field applications. Can perform interrogation of an object within 5 minutes. Can be operated with a palmtop or a laptop computer from a distance of up to 35 m hardwired or up to 70 m through a radio-frequency (RF) connection. Generates neutrons only during the interrogation period. During that time, radiation safety requires an exclusion zone of 8-m radius around PELAN system’s probe. When PELAN system is turned OFF it is safe to approach the probe and place another object in front of it for interrogation. It is also safe to store PELAN without any radiation shielding. It uses no consumables. The data acquisition cycle as well as data analysis can be performed automatically without operator assistance. The start up and shut down of the PELAN requires very little time. The current PELAN has a detection limit of >1 pound of high explosives, which may preclude its use when identifying smaller UXO items or energetic fuses in inert items.

Title: References Text: Department of Defense. Memorandum on Definitions Related to Munitions Response Actions, December 18, 2003. Environmental Security Technology Certification Program (ESTCP). PELAN - A Transportable, Neutron-Based UXO Identification Probe. Naval Explosive Ordnance Disposal Technology Division. 2003. Interim Report for White Oak Ordnance Verification. NAVSEA EOD Technology Division. Womble, P., G. Vourvopoulos, J. Paschal, I. Novikov and A. Barzilov. 2002. Results of Field Trials for the PELAN System. Applied Physics Institute, Western Kentucky University.

Title: Contact Text: For more information about the PELAN, please contact: NFESC POC (805) 982-1656 PRTH_NFESCT2@navy.mil