designated as first-of-a-kind equipment because they are unique, are being designed for this particular application, and have never been used in an actual process. A small-scale test unit called the Technical Risk Reduction Program (TRRP) MPT was fabricated to demonstrate the operation of the MPT concept for the decontamination of metal parts and waste. In this report, the phrase “first-of-a-kind” or “full-scale MPT” is used to describe the full-scale equipment, and the term “TRRP MPT” is used to describe the three-quarter-scale version.

The PCAPP design calls for an MTU to decontaminate the projectile and mortar casings. The MTU, an adaptation of a metal annealing oven, is a continuous-belt muffle-type oven with material-handling equipment at the feed and discharge ends. Modifications include new feed and exit sections and a muffle large enough in cross section (10 in. high by 30 in. wide) to accommodate 155-mm projectile bodies riding on the metal conveyor. The muffle section is also long enough to ensure that all parts of the munitions reach 1000°F for at least 15 minutes at the operating speed of the metal conveyor.

The committee was not charged with evaluating the MTU in detail. What this report presents is a technical description and evaluation of the MPT (Chapters 2-4) plus an evaluation of the technical feasibility of replacing the MPT with an MTU and supplemental decontamination units and autoclaves such as those being designed and tested for PCAPP (Chapter 5).

ASSESSMENT OF METAL PARTS TREATER TESTING ACTIVITIES

The MPT concept has been subjected to testing in TRRPs, with most of the pertinent testing conducted under the Bechtel TRRP 05c test plan (BPBGT, 2007d). This testing has used the three-quarter-scale TRRP MPT.

The testing objectives as given in the TRRP 05c test plan were as follows (BPBGT, 2007d):

  • Demonstrate reliable mechanical performance of all parts and functions of the MPT design, including seals, doors, bearings, and projectile jamming.

  • Demonstrate BGCAPP-specific design improvements such as: projectile orientation, steam-injection orientation, gas take-off orientation, and tray design to improve heatup.

  • Calibrate the computational fluid dynamics (CFD) model of the test unit on VX 155-mm projectiles to serve as a basis for first-of-a-kind (FOAK) full-scale unit modeling. Inherent in this objective is the necessary demonstration that the MPT can heat all parts of materials fed to it to 1000°F for at least 15 minutes at a rate that meets expected feed rates during operation.

  • Demonstrate treatment of simulated energetics batch hydrolyzer (EBH) rocket warhead debris.

  • Demonstrate limited secondary-waste treatment options to gather data for further effort with the CFD model.

  • Perform test runs and cycles of components to make observations of critical design parameters that apply to the FOAK unit under design—particularly those that affect the risk of scale-up to the full-scale unit. These include, but are not limited to projectile paint debris generation and accumulation, thermal expansion stresses and deformation points, interferences, Gaussian field measurements and localized heating effects, and wall temperature distribution.

The TRRP MPT testing used an off-gas treatment system that included a catalytic oxidizer unit rather than a bulk oxidizer unit (more accurately called a flameless thermal oxidizer) and did not include the venturi scrubber. Thus, the flow of off-gas from the MPT enclosures was demonstrated, but not the off-gas treatment system configuration or equipment that will be provided for the full-scale MPT. The off-gas treatment system bulk oxidizer unit is also considered to be a first-of-a-kind system.

TRRP MPT testing was performed using surrogates of all munitions metal parts and waste feed streams anticipated for the two BGCAPP full-scale MPTs. All feed streams were tested. However, the BPBGT terminated the waste stream testing before the completion of all planned tests because it was believed that sufficient data to design the full-scale MPT had been obtained. All feed streams were tested to the extent allowed by existing permits at the Parsons fabrication facility. The permitting limitation prevented testing of the energetics batch hydrolyzer waste with energetics remnants and halogenated materials.

During testing, the TRRP MPT unit experienced recurring operating problems, such as mechanical failures and munitions bodies taking longer than expected to reach the necessary high temperatures as estimated by computer modeling.

The committee grouped the MPT test results into three areas for review and evaluation: (1) mechanical issues and (2) secondary and closure waste treatment issues, which are assessed in this section, and (3) results of thermal testing, modeling, and predicted throughput of the MPT, which are assessed further below.

Mechanical Issues

New Door Closure Mechanism and Seals

Difficulties with getting an acceptably tight closure on the air lock and main chamber doors for the TRRP MPT have resulted in a change in the design of the door closure mechanism and seals for the full-scale MPT. Instead of the J-type sliding closure mechanism used on the TRRP MPT, the door for the full-scale MPT will be moved against the closure face by using a two-direction cam design recommended by a commercial oven contractor. In addition, the seal material design has been altered to give the equivalent of two gaskets between the door and closure face.



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement