Exhibit B to Draft Contract - Tech Specs VD_CRP-SST_SPC-001_V6.0.pdf

BROOKHAVEN NATIONAL LABORATORY

BROOKHAVEN SCIENCE ASSOCIATES

UPTON, LONG ISLAND, N.Y. 11973

PROJECT:

BSA VD CRP-SST – Technical Specification

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Document Number Date

BSA VD CRP-SST

Technical Specification

QA Category: A-2

Prepared by

Nicholas Joniak / Engineer, Physics

Date

Approved by Nicholas Joniak / Technical Representative, Physics Date

Approved by Manhong Zhao / Engineer, Physics

Approved by James Stewart / DUNE Installation Coordinator, Physics

Approved by Gizandra Mussi / Quality Representative, Physics Date

This information is controlled by the U.S.

Department of Commerce Export Administration Regulations 15 CFR Parts 730-774 as EAR99 Technology.

03/10/26

03/10/26

03/11/2026

03/12/2026

03/12/2026

UPTON, LONG ISLAND, N.Y. 11973

PROJECT:

BSA VD CRP-SST – Technical Specification

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Document Number Date

VERSION CONTROL SHEET

VERSION DESCRIPTION DATE AUTHOR APPROVED BY

1 Initial Draft April 01, 2025 N. Joniak N. Joniak

2 Revised Scope Section June 17, 2025 N. Joniak N. Joniak

Updated Section 2 File Names, Section 3.2 Load Cases

July 11, 2025 N. Joniak N. Joniak

Revised per

Reviewer Comments

Aug. 5. 2025 N. Joniak N. Joniak

Revised per PRR

Reviewer Comments

Oct. 30, 2025 N. Joniak N. Joniak

6 Updated Load Case Information Jan. 29, 2026 N. Joniak N. Joniak

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Table of Contents

LIST OF FIGURES

LIST OF TABLES

ACRONYMS

1 INTRODUCTION

1.1 Overview

1.2 CRP-SST Design

2 SCOPE

2.1 Applicable Documents

3 GENERAL DESIGN REQUIREMENTS

3.1 CRP-SST Details

3.1.1 CRP-SST Size and Mass

3.1.2 SURF Conveyance Dimensions

3.1.3 Large SST Subframe Assembly Connection

3.1.4 Assembly Envelope and Tolerances

3.2 Structural Analysis Requirements

4 QA/QC

5 REFERENCES

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List of Figures

Figure 1 Schematics of DUNE/LBNF Figure 2 DUNE Vertical Drift Detector – Top Plate Formed from CRPs and Central Plane from Cathodes Figure 3 Images of the Small SST Figure 4 Images of the Large SST Figure 5 DUNE VD Cathode Unit Figure 6 Concept for the SST Lifting and Adjustment System on Top of the Detector Cryostat Figure 7 Concept for the SST Lifting and Adjustment System on Top of the Detector Cryostat Figure 8 Connection Details Between the Large SST Subframes Figure 9 Small SST Envelope Figure 10 Large SST Envelope Figure 11 Location of CRP Support Points on the Small SST Frame Figure 12 Location of Cathode Support Points on the Small SST Frame Figure 13 Location of Suspension Points on the Small SST Frame Figure 14 Location of CRP Support Points on the Large SST Frame Figure 15 Location of Cathode Support Points on the Large SST Frame Figure 16 Location of Suspension Points on the Large SST Frame Figure 17 SST Suspension Points Figure 18 XYZ Coordinate System for the Small SST Frame Figure 19 XYZ Coordinate System for the Large SST Frame

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List of Tables

Table 1 Global Dimensions and Mass Budget of the Top Detection Plane Components Table 2 Anticipated SST Frame Deformation for Specified Load Cases

Acronyms BSA Brookhaven Science Associates CRP Charge Readout Plane CRP-SST Charge Readout Plane Support Superstructure DUNE Deep Underground Neutrino Experiment FEA Finite Element Analysis LBNF Long Baseline Neutrino Facility QA Quality Assurance QC Quality Control SOW Statement of Work SST Support Superstructure SURF Sanford Underground Research Facility VD Vertical Drift

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1 Introduction

1.1 Overview

The Long Baseline Neutrino Facility (LBNF) is required for the Deep Underground Neutrino Experiment (DUNE) and will be hosted at Fermilab in Batavia, Illinois. DUNE is a dual-site experiment for neutrino science and proton decay studies: the Fermilab site will have the world's highest intensity neutrino beam, and the Sanford Underground Research Facility (SURF) will have the infrastructure to support the construction of massive cryogenic far detectors in their underground caverns. As seen in Figure 1, the SURF caverns are located 1,300 km downstream of the Fermilab beam in the town of Lead, South Dakota.

Figure 1 Schematics of DUNE/LBNF

One of these cryostats will house the Vertical Drift (VD) detector, and two (2) of the main component systems are the central cathode plane and the upper/lower anode planes. The anode planes are integrated into charge readout planes (CRPs), and these components are mounted underneath charge readout plane support superstructures (CRP- SSTs). At the horizontal midplane of the detector is an array of cathode modules suspended with Dyneema ropes from the support superstructure (SST) frames (and pictured in Figure 2). The CRP is a charge sensitive detector component that consists of a glass-fiber composite frame and a stack-up of anode planes and boards. The CRPs are built at facilities located in Europe and transported to the project site at SURF. To place these modules within the detector, a support superstructure frame must first be installed and suspended from the cryostat roof penetrations. The CRPs will then be elevated to final installation height and attached to this frame. The cathodes will be installed at a later time and suspended from this superstructure with 6 m long Dyneema ropes.

The SST frames will be installed at ambient room temperature (22°C/295K), but the cryostat will be cooled down to cryogenic temperatures (-186°C/87K) and filled with liquid Argon prior to the start of operation.

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Figure 2 DUNE Vertical Drift Detector – Top Plate Formed from CRPs and Central Plane from Cathodes

1.2 CRP-SST Design

The CRP-SSTs are mechanical frames used to support the CRP and cathode modules. The DUNE top detection plane is composed of eighty (80) CRPs supported by sixteen (16) SST frames, and there will be two (2) SST types:

1) Four (4) small SSTs at the detector extremeties – these frames can support two (2) CRPs each.

2) Twelve (12) large SSTs in the center portion of the detector – these frames can support six (6) CRPs each.

This specification pertains to both types of SST, and the 3D models of each can be seen in Figure 3 and Figure 4.

In Figure 5 the 3D model of the cathode module is shown: the cathode plane contains eighty (80) of these modules and is a constuction featuring a frame, mesh, and photodetector modules. These units are grouped into supercathodes and hung from the SST frames, with two (2) cathodes comprising the supercathode suspended from the small SST and six (6) cathodes making up the supercathode connected to the large SST. The small SST is designed to support six (6) suspension points and the large SST has twelve (12).

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Figure 3 Images of the Small SST

Figure 4 Images of the Large SST

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Figure 5 DUNE VD Cathode Unit

Each SST will be suspended by four (4) support rods that pass through dedicated feedthroughs (roof penetrations) and attached to the top of the cryostat via a suspension system. This system is a polyvalent device that will be used to both lift the SST frame during the mounting phase as well as support it at the required elevation during the detector operation phase. In order to lift the SST frame from the bottom of the cryostat floor, four (4) synchronized hoists will be mounted above the penetrations on the cryostat roof (see Figure 6a). After this system is used during the lifting process and the SST is elevated to its final position, it will be suspended with support rods and fixed to the structure located on the top of the roof penetration. A mechanical adjustment device, coupled with a bellows, are critical components of this system that allow for fine-tuning of the SST’s position during operation (see Figure 6b).

Figure 6 Concept for the SST Lifting and Adjustment System on Top of the Detector Cryostat

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2 Scope

2.1 Applicable Documents

The document herein defines the technical specification for the BSA VD CRP-SSTs. This document shall be read in conjunction with Brookhaven Science Associates (BSA) document BSA_VD_CRP-SST_SOW-001 and technical specification drawings “2874228-01_-_FD2_CRP-SST-01_10-30-2025” & “2874228-02_-_FD2_CRP- SST-01_10-30-2025”. Also provided are preliminary design level 3D models of both the small and large SST frames.

DOCUMENT TYPE DOCUMENT NUMBER

Statement of Work BSA_VD_CRP-SST_SOW-001 Technical Specification Drawings 2874228-01_-_FD2_CRP-SST-01_10-30-2025

2874228-02_-_FD2_CRP-SST-01_10-30-2025

3D Models FD2-superstr-Middle_set.stp

CRP-SST_Small_Module_V2.0.stp

3 General Design Requirements

3.1 CRP-SST Details

3.1.1 CRP-SST Size and Mass

Table 1 below summarizes the main dimensions and masses of the main components that comprise the top detection plane under warm conditions.

Table 1 Global Dimensions and Mass Budget of the Top Detection Plane Components

Components Approximate Envelope Size

Mass Contingency L W L W

[in] [in] [mm] [mm] [lbs] [kg] [lbs] [kg] Large SST Frame 353.90 265.55 8989 6745 4409 2000 - -

Small SST Frame 117.83 254.92 2993 6475 992 450 - -

CRP 117.83 132.68 2993 3370 353 160 33 15

Cathode 117.83 132.68 2993 3370 220 100 33 15

The large SSTs are large stainless steel frames with an approximate mass of 2,000 kg, and they are constructed from three (3) sub-assemblies. They will be supporting six (6) CRPs and will be connected to the cryostat. The stainless steel grade shall be 304 or higher. The structure shall be produced in accordance with requirements detailed in this technical specification and all documents listed in Section 2.1.

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3.1.2 SURF Conveyance Dimensions

The large SST is designed to be constructed in three (3) sub-assemblies that are field assembled underground at SURF (see Figure 7). This is required both for practicality of surface transport as well as transport feasibility of the frames underground at SURF. The dimensions of the conveyance at SURF is 145 in [3.88 m] depth x 57.25 in [1.45 m] wide x 328 in [8.33 m] height. The conveyance dimensions are considered not to exceed dimensions.

Figure 7 Concept for the SST Lifting and Adjustment System on Top of the Detector Cryostat

3.1.3 Large SST Subframe Assembly Connection

As stated in Section 3.1.2, the large SST will be fabricated and transported in three (3) separate sections. The subframes will be connected at the channel interfaces with bolts as depicted in Figure 8. This connection will be verified during the acceptance testing for all large SST frames (as specified in the BSA SOW document).

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Figure 8 Connection Details Between the Large SST Subframes

3.1.4 Assembly Envelope and Tolerances

Due to the tight space constraints within the detector, the SST frames must fit within a specific envelope. Figure 9 depicts the envelope requirements for the small SST and Figure 10 has the envelope for the fully assembled large SST frame.

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Figure 9 Small SST Envelope

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Figure 10 Large SST Envelope

3.2 Structural Analysis Requirements

The Vendor is required to produce an engineering note (i.e., technical report) containing a detailed finite element analysis (FEA). This structural analysis will be based on the final approved 3D model of the large and small SST frames as detailed in the BSA SOW document, and must be performed using the software program ANSYS.

The vendor is expected to provide analyses based on the following load conditions (and using the masses provided in Table 1).

Small SST Analysis Load Cases:

• Load Case 1 [Ambient Room Temp at 22°C / 295K]: Gravity on SST frame in AIR.

• Load Case 2 [Ambient Room Temp at 22°C / 295K]: Gravity on SST frame in AIR + two (2) CRPs

(CRP 1 + CRP 2) + two (2) cathodes (Cathode 1 + Cathode 2).

• Load Case 3 [Ambient Room Temp at 22°C / 295K]: Gravity on SST frame in AIR for all handlings and transport required of the vendor.

• Load Case 4 [Cryogenic Operating Temp at -186°C / 87K]: Gravity on SST frame in AIR + two (2)

CRPs (CRP 1 + CRP 2) + two (2) cathodes (Cathode 1 + Cathode 2).

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Large SST Analysis Load Cases:

• Load Case 1 [Ambient Room Temp at 22°C / 295K]: Gravity on SST frame in Air.

• Load Case 2 [Ambient Room Temp at 22°C / 295K]: Gravity on SST frame in AIR + six (6) CRPS

(CRP 1 + CRP 2 + CRP 3 + CRP 4 +CRP 5 + CRP 6) + six (6) cathodes (Cathode 1 + Cathode 2 + Cathode 3 + Cathode 4 + Cathode 5 + Cathode 6).

• Load Case 3 [Ambient Room Temp at 22°C / 295K]: Gravity on SST frame in AIR for all handlings and transport required of the vendor.

• Load Case 4 [Cryogenic Operating Temp at -186°C / 87K]: Gravity on SST frame in AIR + six (6) CRPS (CRP 1 + CRP 2 + CRP 3 + CRP 4 +CRP 5 + CRP 6) + six (6) cathodes (Cathode 1 + Cathode 2 + Cathode 3 + Cathode 4 + Cathode 5 + Cathode 6).

The locations of the support points for both the CRPs and cathodes as well as the SST frame suspension points are show in Figure 11 & Figure 12 & Figure 13 for the small SST and Figure 14 & Figure 15 & Figure 16 for the large SST.

It should be noted that some of the cathode support points are coincident.

While each SST will be suspended by four (4) cables, the positions of the large SST anchor points vary throughout the cryostat due to the different penetration locations. The standard configuration is with the suspension points centered along the length of the frame, and the variant positions have the suspension points shifting either to the left or right. Due to the frame being symmetric and the 250 mm shift being the worst case, only the large SST suspension configuration featured in Figure 16 will need to be checked. The small SST suspension configuration is constant for all four (4) instances.

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Figure 11 Location of CRP Support Points on the Small SST Frame

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Figure 12 Location of Cathode Support Points on the Small SST Frame

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Figure 13 Location of Suspension Points on the Small SST Frame

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Figure 14 Location of CRP Support Points on the Large SST Frame

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Figure 15 Location of Cathode Support Points on the Large SST Frame

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Figure 16 Location of Suspension Points on the Large SST Frame

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Figure 17 SST Suspension Points

The structural analysis presented in the engineering note shall demonstrate compliance of both SST frames with the one of the two sets of codes presented below (mixing of US and EU codes is not permissible). The report will contain calculations of the SST structure and all connections as well as a non-linear buckling analysis.

• US Codes:

o ANSI/AISC 360 Specification for Structural Steel Buildings o AISC Design Guide 27 – Structural Stainless Steel o ANSI/AISC 360 Specification for Structural Stainless Steel Buildings o ASCE 7 Minimum Design Loads for Buildings and Other Structures o ANSI/AWS D1.1 Structural Welding Code – Steel

• European Codes:

o EN1990/Eurocode 0 – Basis of Structural Design o EN1991/Eurocode 1 (all applicable parts) – Actions on Structures o EN1993/Eurocode 3 (all applicable parts) – Design of Steel Structures o EN1090 (all applicable parts) – Execution of Steel and Aluminum Structures

The deformation of the structure of under all load cases will be provided as well. A sample set of deformations for select load cases is provided below in Table 2. Unless stated otherwise, the resulting structural analysis deformations shall not deviate more than 20% from the presented values. To ensure that the provided structural

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Table 2 Anticipated SST Frame Deformation for Specified Load Cases

Figure 18 XYZ Coordinate System for the Small SST Frame

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Figure 19 XYZ Coordinate System for the Large SST Frame

4 QA/QC

• Please refer to relevant sections in BSA document: BSA_VD_CRP-SST_SOW-001.

• Inspection and assembly/fitment test at factory prior to shipment.

o All fabrication dimensions and tolerance measurements should be verified with the SST frames laying on a flat metrology table or other flat surface.

No load should be applied to the structure during these checks.

• Inspection upon receipt.

5 References [1] DUNE – An International Experiment for Neutrino Science – DUNE (dunescience.org)

3.2 Structural Analysis Requirements