2.Qualifying a New Manufacturer of FK-800 for NNSA.pdf

Qualifying a New Manufacturer of FK-800 for NNSA

David.Ellrod New Stamp

Contents

Executive Summary ................................................................................................................................... iii Background and Introduction ............................................................................................................ 1-1 Qualification Approach ..................................................................................................................... 2-1 Phases of Qualification ...................................................................................................................... 3-1

Pre-Development Phase ............................................................................................................ 3-1 Development Phase ................................................................................................................... 3-2 Process Prove-In Phase ............................................................................................................. 3-3 Qualification Evaluation Phase ................................................................................................. 3-3

Qualification Schedule ...................................................................................................................... 4-1 Qualification Testing ......................................................................................................................... 5-1

Required Material Quantities .................................................................................................... 5-1 Workflow Diagrams .......................................................................................................................... 6-1 Timing of Implementation ................................................................................................................. 7-1 Intellectual Property .......................................................................................................................... 8-1 Acroynm List .................................................................................................................................... 9-2

Executive Summary

EXECUTIVE SUMMARY

Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL) have used the 3M™ fluoropolymer FK-800 (and its predecessor Kel-F 800) for decades in explosive formulations. As a result of production process changes in the 1990’s, LANL and LLNL worked with

3M™ to optimize the properties of FK-800 for NNSA needs.

In December of 2022, 3M™ announced plans to exit all fluoropolymer production by the end of 2025 because of mounting legal liability stemming from its use of certain toxic fluorinated surfactants in manufacturing a broad range of its products for many years. While this surfactant is not used in FK-800 manufacture, the impending 3M™ exit still requires the National Nuclear Security Administration

(NNSA) to qualify a new manufacturer of FK-800.

In response to a request by NA-193, LANL and LLNL developed a joint framework outlining the testing, sequencing, and material needs required for any qualification effort that would be undertaken to stand up a new manufacturer for FK-800. This document references the joint framework to lay out the general material and testing to progress through the main charge explosive material development process.

This plan is based on LANL, LLNL, and Pantex Plant experience over the last 15 years with the FK-800 optimization effort, in addition to other remanufacturing efforts for both IHE and CHE across the Nuclear

Security Enterprise (NSE). To use any new material from a new manufacturer in a fielded weapon, we need to be confident that it will perform as well as the original material in all weapon environments

(normal and abnormal) for the intended lifetime of the weapon. The material specification for FK-800 is not detailed enough to ensure this, given the complex nature of this polymer and the complex environment in a weapon, and so extended testing to spot check behavior in weapon configurations is required.

The framework can be followed to optimize qualification of a new FK-800 vendor while minimizing the risk of surprise and lengthy recovery during a formal weapon material qualification process. It includes a series of Pre-Development cycles with joint testing between the laboratories to determine that the material, when produced at relevant scales, meets the basic specification requirements and is similar to current FK-800 in extended polymer and PBX formulation testing. When this has been demonstrated, a more formal Development and Qualification effort is executed for each system and includes assembly-and system-level tests, spot checking against recent and current system qualification tests, to ensure that the material produced under a controlled set of manufacturing conditions leads to explosive formulations that perform as well as those made with current FK-800.

Based on experience with the other efforts noted, the Pre-Development effort is expected to take 3 to 5 years while the Development and Qualification portion should require 4 years. There is an opportunity to accelerate this development process when acceptable testing results lead to early off-ramps. Development can proceed at risk on this accelerated timeline, acknowledging some possibility of unexpected results farther downstream in system-specific testing.

Background and Introduction

Background and Introduction

FK-800 is a high-density fluoropolymer used as the binder in the insensitive main charge explosive.

FK-800, originally designated Kel-F 800, has been made by 3M™ Corporation since the 1950s and has been used in nuclear weapon main charge explosives since the 1970s. Department of Energy laboratories stopped buying Kel-F 800 in the early 1990s because of reduced explosive demand due to underground testing prohibition and stockpile reduction efforts. Early synthesis of Kel-F 800 was carried out using a perfluorinated eight carbon (C-8) surfactant, which was found in the 1990s to be toxic, extremely stable, and bio-accumulative. At that time, 3M™ began to remove this surfactant from Kel-F 800 manufacturing, renamed the material FK-800, and adjusted the synthesis so that the resulting product continued to meet the Department of Energy (DOE) nuclear weapon material specification. No FK-800 was qualified for weapon use at that time; although a significant quantity of FK-800 was purchased for future needs and manufacture of mock explosive materials. By 2006, 3M™ had completely removed the surfactant from

FK-800 synthesis.

During the time that the surfactant was being reduced and removed, properties of the FK-800 changed that were outside the material specification but that affect properties of plastic-bonded explosive PBX

9502. Unfortunately, the explosive composite did not have the mechanical strength of material produced prior to 2000. NNSA executed a lengthy and expensive optimization effort from 2015 to 2018 and determined that FK-800 from the new, surfactant-free synthesis process could be used to make acceptable explosive if the allowed content range of one its monomers was tightened by about 3%. FK-800 that meets this tighter specification is now being qualified for weapon use by each program and has shown acceptable behavior in development (Dev) lots.

In December of 2022, 3M™ announced plans to exit all fluoropolymer production by the end of 2025.

3M™’s departure from fluoropolymers requires the NSE to establish a new manufacturer of FK-800 to satisfy current and future needs as well as to mitigate risk associated with unexpected events or material behavior.

Qualification Approach

Qualification Approach

A material becomes qualified for use in a weapon system based on a large body of evidence that often includes

• defined manufacturing equipment at a specified vendor;

• understood and controlled manufacturing processes and constituents;

• developmental (Dev), process prove-in (PPI), and qualification evaluation (QE) lots that meet the material specification requirements;

• acceptable performance of the material in higher level system assemblies in normal and abnormal system environments; and

• acceptable performance of the material in higher level system assemblies after representative aging in normal system environments.

After the evidence is acquired and after the material is officially qualified through various reviews,

• it is only qualified for the weapon system that defined the testing and environments,

• it remains qualified if the assumptions and details of its manufacture do not change, and

• subsequent lots of the material are accepted based only on testing against the material specification.

During production, lot acceptance based only on testing against the material specification is appropriate if assumptions and manufacturing details have not changed subsequent to the QE lot because the extensive work carried out during the qualification effort showed that material produced in that way met system requirements. At that point, there is low risk in accepting against a basic material specification. However, even this low risk is addressed post-production, to an extent, through surveillance disassembly and testing to ensure that nothing unexpected is occurring in the system environment.

During production, any changes in the assumptions or details of the manufacturing process require a re-evaluation exercise that may include extended testing to verify that the changes have not caused differences in material properties that affect behavior in higher level assemblies, even if the material continues to meet specification. This extended testing is often necessary because the basic material specification cannot capture all of the necessary details of the material that make it acceptable for use in all weapon environments. This occurs because (1) the detailed dependence of end-use performance on all input material properties is often not known and (2) the specification generally only covers requirements that the manufacturer can test against.

Changing from 3M™ to a new manufacturer will require this type of re-evaluation exercise for FK-800.

Even if the new manufacturer can seemingly reproduce 3M™’s exact equipment and recipe and make material that meets the current specification, there may be uncaptured subtle differences in some part of the process or constituents that change the details of the polymer that do not become apparent until it is used and aged in an explosive formulation in a system configuration.

The qualification framework presented below is a plan that will be jointly executed by candidate new manufacturers and the NNSA laboratories. The manufactuer will synthesize material and test it against the NNSA material specification requirements. The NNSA laboratories will carry out extended testing on the FK-800, formulate with the FK-800, and test the explosive formulations against current material behavior. The results of the NNSA laboratory efforts, along with their knowledge of current FK-800 synthesis and properties, will be used to help the candidate new manufacturers adjust the synthesis process as needed to ensure that the FK-800 meets the end-state NNSA needs in a weapon environment.

Phases of Qualification

For this effort, qualification of FK-800 will progress through four distinct phases: Pre-Dev, Dev, PPI, and

Qualification. During the phases, there are various gate reviews carried out with a knowledgeable impartial panel that must be passed completely or with small “delta” requirements before entering the next phase. These gate reviews are NNSA activities and do not directly include manufacturer participation, although the results are used to inform subsequent requests for material and possibly synthesis process changes. The phases and general requirements for the gate reviews are described in the below sections.

Pre-Development Phase

In the Pre-Dev phase, the new manufacturer will be working to produce FK-800 with several targets.

• Synthesis at small-batch scales to become familiar with the basics of the polymerization reaction and to provide information to scale up to a useful production level—There will be a significant amount of information provided to the manufacturer regarding FK-800 synthesis at small and large scales, but they will need to become familiar with this surfactant-free emulsion synthesis. It is possible that the manufacturer will want to use some kind of surfactant (non-C-8 fluoropolymer) because that has proven useful in the industry for other products. This approach will likely require more aging and compatibility testing by NNSA to ensure that the new additive does not cause problems in the weapon environment. The end goal of this small-batch phase will be the production of material that approximately meets the material specification although it may have other properties (such as molecular weight and crystallization rate) that differ significantly from the material currently being supplied by 3M™. It is likely not useful to spend significant effort attempting to tune the properties of small polymerization batches becasue there may be very different process parameters needed at a useful production scale because of reaction flow, temperature distributions, etc. in a production-scale vessel. However, a graded approach should be used with smaller-scale batches to evaluate or identify issues earlier and to influence the production-scale processes.

• Installation of equipment (if needed) to make single FK-800 polymerizations at a production scale—This may include upgrades to an existing reaction vessel, a completely new reaction vessel, additional monomer handling and safety infrastructure, and/or drying and packaging equipment as a few examples. The end goal of this installation phase will be the completed process line that is ready to carry out polymerization at a useful production scale (see next list item). This could occur in parallel with continued small-scale batch production to gather more information about the process.

• Demonstration of FK-800 production at a scale useful for PBX 9502 formulation—The smallest useful single polymerization scale is expected to be 300 lb; though this should not be a limiting factor. At the 300-lb level, the resulting batch could lead to (1) a single cycle of FK-800 specification testing, (2) production of a 5000-lb lot of PBX 9502 with reworks, and (3) a single cycle of PBX 9502 specification testing for that lot. A 5000-lb lot of PBX 9502 is the largest individual lot size that can be currently blended from separate 500-lb formulation batches. (A

10,000-lb batch can be ordered but will simply be a cross blend of two 5000-lb blended sub lots).

The quantity of produced LX-17 would be less due to the increased binder material demands for this formulation. Polymerizations smaller than 300 lb could be acceptable but would lead to more cycles of FK-800 specification testing, smaller lots of PBX 9502, and/or more cycles of PBX

9502 specification testing for Pantex. Any single batch synthesized at the 300-lb level will be evidence of meeting this demonstration, even if it does not meet requirements in the FK-800 material specification.

• Adjustment of process parameters to demonstrate synthesis of one production-scale batch of

FK-800 that meets the material specification requirements and produces PBX 9502 that meets basic weapon system compressive and tensile strength requirements—This may be the most time intensive segment of this Pre-Dev phase because each attempt will require a full cycle of PBX

9502 formulation, pressing and/or machining, and strength testing. This set of activities typically takes about 1 full year. Parallel FK-800 batches with different process parameters will make this more efficient from the testing standpoint. Individual 500-lb batches of PBX 9502 can be made from each test lot of FK-800 to determine which process parameters lead to the desired PBX 9502 strengths. This does result in significant amount of leftover FK-800 in this effort, but it will be worth it to examine a range of process parameter combinations in parallel to save time.

In the first part of the Pre-Dev phase, when the full-scale production process has been exercised, test evidence, procedures, methods, etc. will be assessed by a weapon system-appointed panel to meet the intent of a conceptual design review (CDR) to determine that the intended design definition and planned testing are sufficient to address the ultimate qualification requirements for the FK-800 in the weapon systems. After the CDR, when the effort demonstrates synthesis of one production-scale batch of FK-800 that meets the material specification requirements and produces PBX 9502 (or LX-17) that meets basic weapon system compressive and tensile strength requirements, a review that meets the intent of a baseline design review (BDR) will be carried out by the respective weapon system to determine that the design definition is ready to be released and that the Pre-Dev phase may be exited and the full Dev phase entered.

Development Phase

In the Dev phase, the manufacturer is demonstrating reliability and repeatability of the manufacturing process, and the weapons laboratories are carrying out assembly- and system-level tests to determine that the FK-800, when formulated into PBX 9502 (or LX-17), performs as needed from physics, mechanical and aging perspectives. The targets in this phase include the following.

• Demonstrating a repeatable and reliable process—The design definition should be generally stable, the product should have properties with low standard deviations, and the quality aspects should be understood and controlled.

• Making final adjustments to the synthesis parameters and possibly the material specification requirements—Any final changes to the synthesis parameters are made here if needed to bring the material closer to the middle of its tolerance bands, for example, or to improve the quality or efficiency of the process. In some cases, the Dev phase may show that the material specification requirements need to be adjusted for the material to meet system requirements.

• Updating all of the design definition documents to the expected final versions – the current material specification is a joint document that is adequate for all weapon systems that use this binder. It is expected that the specification will continue to be a joint document so that the manufacturer will not be required to produce material with two sets of properties, for example.

At the end of the Dev phase, a review that meets the intent of a final design review (FDR) will be carried out by the respective weapon system to show that the process is reliable and repeatable, that the material meets specification, that the design is stable, and that the material appears to meet system-level requirements. The FDR also addresses producibility of the FK-800 relative to a notional system production schedule. Any gaps, shortcomings, or aspects still needing to be determined or resolved should be minimal and will likely lead to a delta FDR that must be completed before the next phase gate.

Process Prove-In Phase

In the PPI phase, a PPI lot of material and subsequent components are made to provide evidence that a sufficient manufacturing readiness level has been achieved and that details of the manufacturing and acceptance process including facilities, tools, inspection methods, etc. are capable of making material and subsequent components that can be approved for weapon system use. The evaluation of the PPI lot also informs what will be required for engineering evaluation activities in the next phase. Continued testing is carried out in the PPI phase to demonstrate that the material and subsequent components meet requirements. The evidence showing that the PPI phase may be exited will be reviewed in a production readiness review (PRR).

Qualification Evaluation Phase

In the QE phase, a QE lot of material and subsequent components are made and the engineering evaluation walk-down activities are carried out and documented to formally show that the process is capable of making product that can be used in weapon systems. Generally, minimal system-level testing is carried out as a spot check to show expected behavior; although full specification testing will be carried out. The QE phase is completed by issuance of engineering evaluation releases (EERs) and qualification evaluation releases (QERs) referencing the design definition and supporting product and system qualification evidence used to determine that the material and its subsequent components are acceptable for weapon production.

Issuance of QERs by the respective weapon system is the formal qualification of the material and manufacturer.

Qualification Schedule

Qualification Schedule

The qualification schedule for this effort should be considered a reference schedule that will be adjusted as the effort develops and progresses to accommodate needs of the candidate manufacturer (or manufacturers) and to provide for early exit from, or extension of, the Pre-Dev and Dev phases, as needed. The PPI and QE phases are unlikely to be shortened or skipped, and any issue requiring an extension of those phases may result in a recovery effort.

Table 1. Reference Qualification Schedule.

Fiscal Year Phase Details

1 Pre-Development

Installation and/or upgrade of needed infrastructure, and manufacture and testing of small-scale batches to become familiar with the synthesis process

2 Pre-Development

Manufacture and testing of first production-scale batch designated Pre-

Dev 1. Results of testing are used to plan for adjustments in next cycle to improve properties of the FK-800.

3 Pre-Development

Manufacture and testing of production-scale batch designated Pre-Dev 2

Results of testing are used to plan for adjustments in next cycle to improve properties of the FK-800.

4 Pre-Development

Manufacture and testing of production-scale batch designated Pre-Dev 3

Results of testing are used to plan for adjustments in next cycle to improve properties of the FK-800.

5 Pre-Development

Manufacture and testing of production-scale batch designated Pre-Dev 4

This batch should meet the material specification and show promising strength results when formulated into a production-scale batch of PBX

9502/LX-17 at Holston.

6 Development

Manufacture and testing of Dev Lot 1. Results demonstrate a reliable and repeatable process and provide material for system-level tests. Minor adjustments to the process or design may be needed.

7 Development

Manufacture and testing of Dev Lot 2. Results demonstrate a reliable and repeatable process and provide material for system-level tests. At this point, no further adjustment of the process or design should be needed. A

FDR is completed, allowing progression to the PPI phase.

8 Process Prove In

Manufacture and testing of the PPI lot. All parts of the process at the manufacturer and explosive production agencies are exercised to demonstrate that acceptable material is produced. This process is used to develop data needs for the engineering evaluation component of the QE phase. This also provides material for short-term, system-level tests. A

PRR is completed, allowing progression to the QE phase.

Qualification

Evaluation

Manufacture and testing of the QE lot. All parts of the process at the manufacturer and explosive production agencies are exercised and selected aspects are observed per the details fo the engineering evaulation documentation. Successful results lead to QERs for the new FK-800 and

PBX 9502/LX-17 using it. Material is approved for weapon production activities.

Qualification Testing and Costs

Qualification Testing

Testing needs have been developed based on experience with the FK-800 recovery effort executed between 2015 and 2018 and the PBX 9502 qualification efforts. For planning purposes, NNSA has defined what it believes to be the optimal FK-800 material quantities to execute the testing plan in section

5.1.

Testing will cover (1) standard material specification testing, (2) other testing found useful during the recovery effort, and (3) a subset of system-relevant testing that spot checks the behavior of the material against expected Legacy and new production performance.

Required Material Quantities

The required quantities of materials have been estimated based on the testing plan and are listed in Table

5. Because this effort aims to qualify a new manufacturer outside of a standard full-weapon

Modernization Program or material Dev effort, the PPI and QE lots remain at Dev quantities instead of being increased to provide material that could yield to War Reserve. If there is a full Modernization

Program or Dev effort that this can be linked to, those PBX or LX quantities may be increased , possibly to ~1800 lbs.

Table 5. Required Material Quantities.

FY Phase FK-800

1 Pre-Dev 1 50

2 Pre-Dev 2 300

3 Pre-Dev 3 300

4 Pre-Dev 4 300

5 Pre-Dev 5 300

6 Dev 1 600

7 Dev 2 600

8 PPI 600

9 QE 600

– Totals 3650

Workflow Diagrams

Figure 1 shows the notional workflow diagram for the Pre-Dev effort. With this view, it is clear that there are several off-ramps within the Pre-Dev testing cycles that move effort back to the next manufacturer iteration instead of continuing on with larger scale and more extensive tests. The last block in the diagram is also an off-ramp that allows early exit of the Pre-Dev cycle if all results are acceptable. Off-ramp detail is in the next section.

Vendor makes 300 lb batch

Pantex tests against material spec

Passes Spec?

No

DA basic tests including crystallization and small-scale PBX strength

Yes

Meets expectations?

No

DA larger scale and extended tests

Holston 500 lb formulation

Yes

Meets expectations?

Pantex tests against material spec

(including strength)

Passes Spec?

No

No

Next iteration of Pre-Dev or Exit to Dev

Yes

Yes

Figure 1. Workflow diagram for Pre-Dev cycle efforts.

Figure 2 shows the notional workflow diagram for the Dev/Qual effort. With this view, it is clear that there are several triggers within the Dev through Qualification testing cycles that can lead to additional lots from the manufacturer (as well as possibly additional tests).

Vendor makes 300 lb batch

Pantex tests against material spec

Passes Spec?

DA basic tests including crystallization and small-scale PBX strength

Yes

Meets expectations?

Holston 500 lb formulation

Pantex tests against material spec

(including strength)

Passes Spec?

Yes

Move to next higher pedigree

LANL Initial PRT and Local Tests

LLNL Initial PRT and Local Tests

Meets expectations?

Meets expectations?

Request for additional Dev or PPI lot

No

No

No No

LANL

trigger tests

LLNL

trigger tests

No

LANL extended PRT and Local Tests

LLNL extended PRT and Local Tests

Yes Yes Yes

Meets expectations?

Meets expectations?

All inputs Yes

Yes Yes

No No

Figure 2. Workflow diagram for Dev through Qualification cycle efforts.

Timing of Implementation

An examination of the expected schedule for current FK-800 production and early views of future system needs suggests that this effort to qualify a new manufacturer should begin in or near FY25. This ensures that current personnel from all institutions will still likely be involved so that there is not a gap in effort that will require substantial knowledge transfer before starting to qualify a new manufacturer. In addition, an FY25 start would position the new manufacturer well to be able to step into Phase 1 efforts for a future system based on NNSA’s current plans.

Intellectual Property

All intellectual property developed in the course of these efforts will be owned by NNSA. Before commencement of the activities, a formal agreement should be in place regarding this requirement.

Acroynm List

Acronym Definition

BDR baseline design review

C-8 eight carbon

CDR conceptual design review

DA Design Agency

Dev development

DOE Deparment of Energy

EER engineering evaluation release

FDR final design review

FY fiscal year

LANL Los Alamos National Laboratory

LLNL Lawrence Livermore National Laboratory

LOP life-of-program

LX Lawrence Livermore eXplosive

NSE Nuclear Secuirty Enterprise

NNSA National Nuclear Security Administration

PBX plastic-bonded explosive

PPI process prove-in

PRR production readiness review

QE qualification evaluation

QER qualification evaluation release

SITI Sandia Instrumented Thermal Ignition test

SME subject matter expert

TATB Triaminotrinitrobenzene

US United States