i

National Institute of Standards and Technology

Schematic Design for Site Underground Utilities Replacement

June 2024

Metropolitan Architects and Planners, Inc.

with A f f i l i a ted Eng ineers , Inc . , and A lpha Corporat ion i

TABLE OF CONTENTS

Executive Summary Project Description Relevant Codes and Standards Design Conditions and Assumptions Mechanical Thermal Util i ty Distr ibution Electr ical Uti l i ty Distr ibution Phasing and Sequencing Section 2: Specifications

F2020 Hazardous Components Abatement G1010 Site Clearing G1020 Site Demolition And Relocation G1030 Site Earthwork G2012 Paving & Surfacing G2016 Markings & Signage G2030 Pedestrian Paving G2032 Edging G2054 Seeding And Sodding G3000 General Mechanical Requirements for Thermal Utilities G3001 Mechanical Piping and Equipment Supporting Devices G3002 Mechanical Systems Identification G3010 Water Supply G3020 Sanitary Sewer G3030 Storm Sewer G3041 Steam Supply G3042 Condensate Return G3045 Heating System Valves and Piping Specialties G3046 Heating Pipe Insulation G3051 Chilled Water Piping G3055 Chilled Water System Valves and Piping Specialties G3056 Chilled Water Pipe Insulation G3093 Natural Gas Piping G4000 General Electrical Requirements G4001 Underground Electrical Service G4002 Electrical Systems Commissioning Requirements G4003 Electrical Systems Identification G4004 Power Distribution Acceptance Tests G4005 Power Distribution Acceptance Test Tables G4013 Underground Electrical Distribution G4023 Wiring Conduits & Ductbanks G9010 Service and Pedestrian Tunnels

Appendices (under separate cover)

A. Engineering Drawings

B. Sanitary Sewer Computations

C. Preliminary Geotechnical Engineering Report ii

Location of Central Utility Plant, NIST Gaithersburg Campus

S i t e U n d e r g r o u n d U t i l i t i e s R e p l a c e m e n t

J u n e 2 0 2 4 1

Executive Summary

The National Institute of Standards and Technology (NIST) headquarters campus in Gaithersburg, Maryland sits on approximately 579 acres with the first buildings constructed at the beginning of the 1960’s. Of the currently existing 62 buildings and structures, approximately half are more than 50 years old. The associated underground utilities are in many cases beyond their respective service life and undersized to meet the projected capacity requirements. The current Master Plan identifies numerous new facilities and existing facility expansions, and the intent of this campus-wide utility system upgrade and replacement is to provide the infrastructure capacity for those. These utility distribution infrastructure upgrades are coordinated with the replacement/expansion of the Central Utility Plant (CUP), with upgrades to the heating and cooling systems as well as to electrical power systems.

The Schematic Design for the Replacement of Underground Utilities (SDRU) includes approximately 46.6 miles of new underground utilities. Therefore, there will be approximately the same amount of existing underground utilities to be demolished.

The SDRU is intended to be the basis for the RFQ/RFP process to select the Design Engineer for a DBB procurement.

Project Description

This is a multi-phase multi-year project for the replacement of underground utilities, incorporating future growth of utility loads. The Design Engineer will need to locate and test-hole the campus wide existing utilities for their use in the design of this program. The design engineer will also need to run a new topographical survey.

The utilities to be replaced include campus cooling, campus heating, power distribution, signal and communications, natural gas, and combined domestic/fire water. Sanitary sewer and storm sewer will need to be evaluated from manhole/structure to manhole/structure to determine if they should be replaced.

Full replacement utilities will be installed in new locations to allow the associated existing utilities to remain in service throughout construction. Crossover valve vaults will be installed at phase lines and at building utility entrances to be used for switchovers from existing to new. Storm and sanitary sewer that is identified as needing replacement will be installed in the same alignments that exist. These replacements will be done utilizing pump-arounds as necessary to maintain campus service. Continuous campus operation during construction is a requirement of this project.

Utility manholes/vaults and expansion/contraction areas are provided and can be added or deleted as necessary once the schematic layout is accepted. The project phasing has been determined and is discussed below in the Phasing and Sequencing section. There are five (5) phases for the utilities except for electrical which has 3 overlapping phases. Phasing can be adjusted by the Designer to be based on cost, location, looping, and redundancy requirements, or future schedules of new construction.

The following table shows lengths of utilities except for storm sewer. Proposed storm sewer is not shown in the drawings since it will be replaced in the same location on an as-needed basis and much of it may remain.

Sanitary sewer is shown as proposed in the drawings as it is assumed that most of it will be replaced since much of it is transit pipe (asbestos-concrete).

N a t i o n a l I n s t i t u t e o f S t a n d a r d s a n d T e c h n o l o g y

F i n a l S D R U

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Utility Total Length (LF) Total Length (Miles) ST –Steam line 21,672.630 4.10

STCO – Steam condensate 20,906.935 3.96

CHWS – Chilled water supply line 22,365.306 4.24

CHWR – Chilled water return line 22,433.370 4.25

SAN- Sanitary sewer main 31,560.043 5.98

W –Water line 36,001.760 6.81

G –Gas line 28,572.394 5.41

EDB –Electric-ductbanks 31,948.897 6.05

CDB –Communication-ductbanks 30,588.162 5.79

Relevant Codes and Standards

The following applicable codes and standards are associated with the SDRU proposed utilities:

Maryland State Highway Administration Standards and Specifications for Construction and Materials

Maryland Stormwater Management Manual

Maryland “Stormwater Management Act of 2007”

Maryland Stormwater Management Guidelines for State and Federal Projects

COMAR 26.17.02

Washington Suburban Sanitation Commission (WSSC) Standard Specifications

Washington Suburban Sanitation Commission (WSSC) Standard Details for Construction

Architectural Barriers Act (ABA)

Energy Independence and Security Act of 2007, Section 438

National Fire Protection Association Codes and Standards

International Code Council (ICC)

The latest edition of the codes and standards, at the time of award, shall be applicable.

Design Conditions and Assumptions

This project is envisioned as a mix of walkable tunnels and direct-buried utilities. Addition of non-walkable tunnels is an enhancement option for some of the utility replacements shown to be direct-buried systems.

Thermal utilities including high pressure steam, pumped condensate, high pressure condensate, and chilled water pipes will likely be a combination of direct bury, non-walkable tunnels, and/or walkable tunnels. See the thermal utilities section for additional details.

All other utilities shall be direct-buried except for electrical power and telecommunications which will utilize concrete encased duct banks. All utilities will be replaced except for storm sewer and sanitary sewer which will be inspected by the design engineer to determine the extent of replacement required.

A current up to date topography that shows the current conditions is required to be obtained by the design team. The utilities have not been field located. Existing utilities will need to be located both horizontally and vertically in conjunction with topography update.

J u n e 2 0 2 4 3

The existing campus wide compressed air system is not to be replaced or disturbed. Individual compressors will be installed to serve new buildings as needed. During construction if a compressed air line is unearthed and has a leak it shall be repaired before being covered up. Once existing utilities are located by the Designer, care can be executed to minimize disturbance of the existing compressed air lines during construction.

Heating Systems – The existing steam and condensate return systems will be replaced in a phased approach.

New components of the steam system will be sized in a manner that the system can be converted to Heating Hot Water (HW). This requires sizing the condensate return so it can serve as a heating hot water return should the central plant system be converted to a heating hot water system.

Cooling Systems – The entire existing chilled water system, including supply and return piping, shall be replaced in a phased approach. The system will be sized to meet the overall demand of the campus with the new facilities as well as proposed facility expansions.

Electrical Power Distribution – The intent is to fully upgrade the existing medium voltage distribution system with a new system of duct banks, vaults, and manholes. All existing medium voltage duct banks and conductors will be replaced as there are numerous collapsed/blocked ducts campus-wide, the size of the conduits is in many cases insufficient to accept larger conductors and the system is subject to water intrusion.

Telecommunication Distribution – The intent is to fully upgrade the telecommunication distribution systems with a new system of duct banks, communication vaults, and manholes. All existing duct banks and manholes will be replaced, as there are numerous collapsed/blocked ducts across the campus.

Sanitary Sewer – Information received from NIST indicates that many of the sanitary sewer pipes are transit (asbestos-concrete). Transit pipe in good condition can remain in service. NIST may choose to replace all the transit pipes regardless of condition. If this is the case, CCTV inspection will not be necessary and a simple visual inspection to verify the pipes are Transit can be performed. The intent is to replace sanitary sewer systems to the extent necessary, to be determined by the design engineer through condition assessment during the pre-design stage of this program. This system will be replaced in its current location. The campus is served by a sanitary sewer system starting with 8-inch, then 12-inch, then 15-inch and finally to 18-inch that travels through the south end of the campus to the outfall.

An analysis of the existing sanitary systems was performed to assess the system’s ability to handle proposed building expansion as well as new building construction. The analysis performed uses the square footage of the of the buildings in their final configuration (with expansions) multiplied by 0.16 GPD per square foot. This results in an incremental flow for the square footage, a peak factor is applied to provide peak hour flow in MGD. This flow is compared to the full capacity of a pipe in MGD to show the percent full of the pipe analyzed.

The analysis looked at the main collector pipes (15”) along south drive on either side of center drive. Also analyzed is the final pipe run (18”) leaving the campus. We also looked at pipes that are collectors for multiple buildings. These pipes were either 8” or 12”. Because no vertical information is available at this stage all pipes were analyzed using a 0.50% slope. The pipes analyzed were all below capacity. The system as it currently configured has enough extra capacity to accommodate the proposed expansions and new building constructions.

See Appendix B for sanitary sewer computations.

Storm Drain - The intent is to replace storm drain systems to the extent necessary, to be determined by the design engineer through condition assessment during the pre-design stage of this program. These systems will be replaced in their current location. It should be anticipated that alteration to the overall systems may be necessary to address Storm Water Management (SWM) requirements for each respective project requiring SWM facilities. The sizing of the replacement systems should not change since SWM plan implementation

4 Metropolitan Architects and Planners, Inc. | Affiliated Engineers, Inc. | Alpha Corporation generally reduces or maintains current discharges through the preferred point source treatment and environmental site design process. All grate inlets and combined drop/grate inlets are to at a minimum have the tops replaced.

Potable Water – The combined domestic/fire water systems are to be replaced including the fire hydrants.

These systems will be replaced to provide sufficient capacity to meet the planned domestic demand, to support fire suppression system demand at each facility, to support proposed looping/redundancy requirements, and to incorporate sufficient isolation valving to facilitate maintenance of service when maintenance or repairs to the system are required. Potable water replacement for fire protection needs to include proper pipe sizing to allow for sprinklers to be installed at all buildings.

Natural Gas – The existing natural gas lines are to be replaced except for the high-pressure gas lines, serving the central plant, which will remain. The replacement piping will be the yellow medium density polyethylene pipe to match the existing gas line sizes. The use of natural gas at NIST is expected to be slowly reduced, therefore no pipe size increases should be necessary. Design will need to incorporate sufficient valving to facilitate phasing switchovers and maintenance of service when repairs to the system are required.

Vibration Control - Portions of the utility distribution network will require special consideration for vibration during construction because of proximity to laboratories and sensitive equipment. Of specific concern are areas near the Advanced Measurement Laboratory (AML) buildings - B215, B216, B217, B218 and B219.

The research in these buildings is highly sensitive to vibration. Using two main types of vibration isolation, strict vibration control was achieved in the AML buildings. Isolated slabs-on-grade separating the service corridors and structural framing from the laboratory space aid in vibration noise reduction. The most sensitive laboratory space is located within the basement, away from common sources of surface and wind induced vibration. Further, the use of vibration isolation spring technology, active, and passive vibration systems custom tailored to specific vibration needs provides even more stringent vibration control where required.

Above-grade laboratories in these facilities also contain some vibration sensitive equipment. The project teams must hire a specialist with expertise in the vibration field to ensure that proper steps are taken throughout design and construction to minimize any impact to ongoing research. Coordination among the campus staff and the construction team, including a vibration expert, will be required to minimize disturbance during construction, allowing for work to be completed in times not interfering with work in proximate laboratories.

Structural Considerations

The structural drawings include details for various options and configurations of the supporting structures for the utility distribution. The vaults, tunnel, and tunnel junction areas provide reinforced concrete structures to be used where applicable.

The following applicable codes and standards are associated with the structural work:

International Building Code

ASCE 7 – Minimum Design Loads for Buildings and Other Structures

ACI 301 – Standard Specifications for Structural Concrete

ACI 318 – Building Code Requirements for Structural Concrete

AWS D1.4 – Structural Welding Code – Reinforcing Steel

The latest edition of the codes and standards, at the time of award, shall be applicable.

The proposed utility tunnel options are reinforced concrete with vaults for steam/chilled water. Electrical vaults can be precast concrete vaults as specified by Pepco details and specifications. Sections of walkable tunnel are

J u n e 2 0 2 4 5 proposed to support utilities on either side of the tunnel with a walking corridor down the center. A non-walkable tunnel provides a value engineering option to replace sections of direct-buried utilities. At connection junction, a proposed t-junction provides a connection at intersections of the utility tunnel for access hatch to grade.

At this time, there is no geotechnical report available, so the ground water table was assumed to be at a depth of 5 feet below the ground surface. There will not be an easy way to provide a method of drainage around the vaults and tunnel walls so the design utilized undrained soil properties. It is assumed that shallow ground water is present, and the vaults will be subjected to buoyancy. In order to resist buoyancy, the bottom slab thickness is increased and a horizontal projection from the face of the wall is added. The top slab is assumed to brace the walls against rotation, so at rest soil pressures were utilized in the design of vault and tunnel walls.

Throughout the campus, the tunnels and vaults will be in the roadway and subjected to vehicle loading. The top slabs include design considerations for additional loading. The slab spans include analysis for the calculated moment and the appropriate distribution of reinforcement is present to provide lateral distribution of the concentrated live loads.

The tunnels and vaults will require a waterproofing system applied to all surfaces to prevent water intrusion.

All construction joints will require a waterstop. Sump pits/pumps will be required in the vaults. Additionally, drainage systems will be required inside the tunnels and tunnel support structures. These can include a combination of sump pits/pumps and drainpipes.

The options provided below are included on the structural drawings. The intent is that the various options can be added or removed as desired based on funding and the tunnel sections can be converted to direct bury if needed.

There are four types of vaults, sizes noted are minimum size examples. Contractor to provide larger vaults as necessary depending upon the size of pipes and configurations to provide access and maintenance:

Steam: 12’x12’x8’ clear

12” steam and 8” condensate return

Top of vault assumed to be up to 5 feet below grade

Chilled Water: 8’x8’x8’ clear

12” steam and 8” condensate return

Top of vault assumed to be up to 5 feet below grade

Electrical: 10’x10’x8’ clear

24”x30” ductback

Top of vault assumed to be near grade

Telecom: 8’x8’x8’ clear

24”x30” ductbank

Top of vault assumed to be near grade

There are four distinct underground structures associated with the walkable tunnel:

Typical main tunnel section: 15’ wide x 11’ tall clear

Chilled Water Take-Off: 24’ x 13’ x 14’-6” tall clear

Steam Take-Off: 31’ x 13’ by 14’-6” tall clear

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Tunnel T-Junction: 35’ x 35’ by 14’-6” tall clear

Mechanical Thermal Utility Distribution

A. Existing Conditions

Existing chilled water supply and return piping is distributed from the existing CUP to buildings throughout the NIST campus mostly following existing roads. Piping is direct-buried. In addition, high pressure steam and pumped steam condensate is distributed and returned to and from buildings around the campus from the CUP. High pressure condensate drip lines are discharged directly into the pumped condensate return system.

NIST has had problems with the direct discharge of high-pressure condensate into the pumped condensate lines causing cavitation. Steam and condensate lines along the south leg of the campus are temporarily routed above ground due to failures. The following table provides the existing design of the steam and chilled water distribution systems.

System Design Conditions

System Design Temperature (°F) /

Pressure Differential Temperature (°F) High Pressure Steam (Campus) 375°F at 150 psig saturated -

High pressure Condensate 365°F at 150 psig

Pumped Condensate Return 250°F at 15 psig saturated -

Chilled Water (Campus) 42 13

B. New Work

The existing distribution system is to be replaced and sized per future Master Plan building requirements in a phased approach.

The existing and future loads for the campus were determined via a review of historical campus usage of chilled water, steam, and electricity, in conjunction with a campus wide load calculation. A load calculation was performed for each existing building on campus. For future buildings and additions, the program of requirements for those buildings were reviewed. Where loads were provided in the POR, these were utilized.

Calculations were also performed for the future buildings and additions based upon the types of programs and space allocations for these buildings. From these building loads, energy profiles and models were further developed.

Following is a summary of the calculated campus loads for steam, chilled water, and electrical power.

Figure 3.A.1: Existing Campus Loads

Building Area GSF

CUP

Cooling

Y/N

CUP

Heating

Y/N

Cool-ing

Tons Heating

MBH

Elec-trical power kVA

CUP

Cooling

Tons

CUP

CHW

GPM

CUP

Heating

MBH

Existing

101 Administration Building

358,312 Y Y 1,343 14,415 991 1,343 2,480 14,415

103 Visitors Center 2,467 N N 6 40 16 0 0 0

202 Engineering Mechanics

78,577 Y Y 755 6,193 739 755 1,393 6,193

J u n e 2 0 2 4 7

Building Area GSF

CUP

Cooling

Y/N

CUP

Heating

Y/N

Cool-ing

Tons Heating

MBH

Elec-trical power kVA

CUP

Cooling

Tons

CUP

CHW

GPM

CUP

Heating

MBH

203 Standard Reference Material Facility

24,915 Y Y 167 1,284 648 167 308 1,284

205 Large Fire Facility 48,750 Y Y 460 5,423 147 460 849 5,423

205E Emissions Control Electrical

260 N N 0 4 2 0 0 0

205M Emissions Control Mechanical

322 N N 0 5 2 0 0 0

206 Concrete Materials 8,166 N Y 95 932 138 0 0 932

207 Robotics Test Facility 9,898 N N 115 1,130 148 0 0 0

208 Net Zero Energy Residential Test

7,375 N N 16 118 111 0 0 0

215 Nanofabrication Facility

109,369 Y Y 1,129 8,627 1,012 1,129 2,085 8,627

216 Instrument East 106,177 Y Y 725 4,238 924 725 1,339 4,238

217 Instrument West 129,373 Y Y 620 4,707 1,131 620 1,145 4,707

218 Metrology East 106,739 Y Y 573 3,913 1,148 573 1,058 3,913

219 Metrology West 84,880 Y Y 313 2,341 901 313 578 2,341

220 Metrology 216,068 Y Y 1,187 12,368 1,278 1,187 2,192 12,368

221 Physics 219,654 Y Y 1,371 14,395 1,456 1,371 2,531 14,395

222 Chemistry 166,101 Y Y 631 6,330 613 631 1,164 6,330

223 Materials 164,659 Y Y 808 8,272 912 808 1,492 8,272

224 Polymers 164,028 Y Y 836 8,678 983 836 1,543 8,678

225 Technology 204,332 Y Y 873 8,756 1,408 873 1,612 8,756

226 Building Research 142,805 Y Y 792 8,520 891 792 1,463 8,520

227 Advanced Chemical Sciences Lab

231,835 Y Y 1,059 9,992 1,189 1,059 1,955 9,992

230 Fluid Mechanics 38,367 Y Y 360 4,091 355 360 664 4,091

231 Industrial 75,121 Y Y 629 6,976 628 629 1,161 6,976

233 Sound Laboratory 42,888 Y Y 338 3,674 285 338 624 3,674

235 NIST Center for Neutron Research

229,849 Y Y 1,727 18,867 1,824 1,727 3,189 18,867

236 Special Projects 6,689 Y Y 149 1,252 92 149 275 1,252

237 Non-Magnetic Building (237)

3,099 Y N 30 289 17 30 56 0

238 Non-Magnetic Building (238)

3,961 Y N 75 642 47 75 139 0

245 Radiation Physics 276,192 Y Y 1,346 10,517 1,396 1,346 2,485 10,517

245 Radiation Physics H- Wing Addition

74,144 Y Y 790 8,905 833 790 1,459 8,905

245 Radiation Physics D- Wing Addition

13,548 Y Y 85 527 848 85 157 527

301 Supply and Plant 163,761 Y Y 269 1,287 352 269 496 1,287

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CUP

Cooling

Y/N

CUP

Heating

Y/N

Cool-ing

Tons Heating

MBH

Elec-trical power kVA

CUP

Cooling

Tons

CUP

CHW

GPM

CUP

Heating

MBH

302 Steam + CW Generation Plant (incl.

CHP)

65,403 Y Y 71 182 22,100 71 131 182

303 Service Building 14,573 Y Y 36 282 37 36 67 282

304 Shops Building 75,588 Y Y 440 3,778 436 440 813 3,778

305 Switchgear/Cooling Tower

16,162 N N 23 238 24 0 0 0

306 Electric Substation 4,532 N N 6 67 7 0 0 0

307 Materials Processing Storage

373 N N 1 5 2 0 0 0

309 Grounds Maintenance

11,702 N N 26 188 70 0 0 0

310 Plant Storage Building

505 N N 1 7 3 0 0 0

311 Grounds Storage Shed

2,511 N N 4 37 11 0 0 0

312 Materials Processing Facility

3,877 Y Y 7 75 37 7 14 75

313 Site Effluent Neutralization

245 N N 3 28 0 0 0 0

314 Backflow Preventor - East

663 N N 1 10 1 0 0 0

315 Backflow Preventer - North

663 N N 1 10 1 0 0 0

316 Electrical Service Building

487 N N 1 7 1 0 0 0

317 Cooling Tower 3,441 N N 5 51 12 0 0 0

318 Emergency Services Facility

22,127 N N 32 326 77 0 0 0

319 Emergency Services Storage

312 N N 0 5 2 0 0 0

320 Childcare Center 23,686 Y Y 91 931 83 91 168 931

321 NCNR Storage 2,666 N Y 4 39 4 0 0 39

411 Building 411 17,358 N N 39 279 102 0 0 0

418 NCNR Storage Building

3,000 N N 4 44 16 0 0 0

420 OFPM Storage Building

2,615 N N 4 39 11 0 0 0

421 Radiation Physics Storage

1,499 N N 2 22 7 0 0 0

422 Concrete Materials Storage

1,200 N N 2 18 7 0 0 0

423 Research House 2,258 N N 3 33 46 0 0 0

426 Building 426 - Temporary

663 N N 1 10 4 0 0 0

427 Building 427 - Temporary

663 N N 1 10 4 0 0 0

J u n e 2 0 2 4 9

CUP

Cooling

Y/N

CUP

Heating

Y/N

Cool-ing

Tons Heating

MBH

Elec-trical power kVA

CUP

Cooling

Tons

CUP

CHW

GPM

CUP

Heating

MBH

428 Building 428 - Temporary

2,823 N N 4 42 18 0 0 0

Connected Corridor 13,908 Y Y 31 223 73 31 57 223

Process Load Y Y 1,200 20,000 1,200 2,215 20,000

Post 2020-Exisiting Campus Total(1)

3,734,040 20,529 37,899 202,087

Post 2020-Exisitng Campus Block Total(1)

3,734,040 17,039 31,456 143,481

Post 2023-Exisiting Campus Total

3,808,184 46,658 21,319 39,358 210,991

Post 2023-Exisitng Campus Block Total

3,808,184 37,327 17,695 32,667 149,804

Master Plan Phase 1

245 Radiation Physics E- Wing Addition

11,844 Y Y 2,245 1,333 134 2,245 4,145 1,333

228 Research Building I 243,000 Y Y 1,137 13,203 2,500 1,137 2,099 13,203

101 Administration Building Addition

50,000 Y Y 88 991 1,947 88 163 991

326 Gate F Shipping/Receiving/ Inspection

17,000 N N 117 1,327 750 0 0 0

209 Response Robotics Test Facility

10,000 N N 75 851 333 0 0 0

222 Chemistry Addition 28,000 Y Y 49 555 92 49 91 555

302 CUP Modernization + Expansion

0 TBD TBD

104 Gate F Visitor Center 4,400 N N 21 239 0 0 0 0

221 Physics Addition 28,000 Y Y 49 555 92 49 91 555

South Utility Loop 0 TBD TBD

103 Visitors Center Addition

3,000 Y Y 5 59 220 5 10 59

Local elec. Power for building conditioning 4,810

Sub Total 395,244 10,879 3,575 6,599 16,696

Sub Block Total 395,244 8,703 2,967 5,477 11,854

Total After Phase 1 4,203,428 57,537 24,745 45,682 225,502

Block Total After Phase 2 4,203,428 46,030 20,538 37,916 160,107

Master Plan Phase 2

226 Building Research Addition

28,000 Y Y 49 555 92 49 91 555

242, 243, 244 New Research Buildings II, III, IV

415,000 Y Y 1,656 19,386 4,800 1,656 3,057 19,386

324 Parking Structure 246,000 N N 0 0 2,000 0 0 0

328 Gaithersburg Computing Facility

44,000 Y Y 1,400 3,849 7,500 1,400 2,585 3,849

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CUP

Cooling

Y/N

CUP

Heating

Y/N

Cool-ing

Tons Heating

MBH

Elec-trical power kVA

CUP

Cooling

Tons

CUP

CHW

GPM

CUP

Heating

MBH

Local elec. Power for building conditioning 1,820

Sub Total 689,000 16,212 3,105 5,733 23,790

Sub Block Total 689,000 12,970 2,578 4,758 16,891

Total After Phase 2 4,892,428 73,749 27,850 51,415 249,292

Block Total After Phase 2 4,892,428 59,000 23,115 42,675 176,997

Master Plan Phase 3

214 AML Addition 115,000 Y Y 1,148 12,943 121 1,148 2,119 12,943

Concrete Materials Addition

0 TBD TBD 0 0 0

210 Fire + Wind Facility 158,000 Y Y 659 7,616 5,588 659 1,216 7,616

329 New Electrical Switching Station

0 TBD TBD 0 0 0

235 NIST Center for Neutron Research Addition

138,000 Y Y 1,377 15,532 1,518 1,377 2,542 15,532

232 Standard Reference Materials Building

93,220 Y Y 379 4,359 1,130 379 700 4,359

Strong Floor Building 40,000 Y Y 399 4,502 440 399 737 4,502

Local elec. Power for building conditioning 5,720

Sub Total 588,220 14,517 3,962 7,314 44,953

Sub Block Total 588,220 11,614 3,288 6,071 31,916

Total After Phase 3 5,480,648 88,267 31,812 58,730 294,245

Block Total After Phase 3 5,480,648 70,613 26,404 48,746 208,914

1) Post 2020-Existing Campus Total and Post 2020-Existing Campus Block Total do not include 245 Radiation Physics H-Wing

Addition as this addition was completed in 2022.

2) Building 206 is planned to change to local heating via heat pump. Future design to coordinate requirements with NIST.

Building 206 heating load is included in the existing campus totals. Building 206 heating load is excluded from Master Plan Phase 1, 2, 3 totals.

3) Building 236 is planned for demolition. Future design to coordinate requirements with NIST. Building 236 cooling and heating loads are included in the existing campus totals. Building 236 cooling and heating loads are excluded from Master Plan Phase 1, 2, 3 totals.

Thermal utilities including high pressure steam, pumped condensate, high pressure condensate, and chilled water pipes will be either all direct bury or a mixture of direct bury, non-walkable tunnels, and / or walkable tunnels. The final solution will be determined based upon funding availability for the NIST campus and NIST direction. Schematic design documents include the following:

• Base: Direct-buried with limited portion of concrete encased walkable tunnels.

• Alternate 1: All direct-buried.

• Costing shall be provided to replace direct-buried piping and walkable tunnels with non-walkable pipe tunnels on a linear foot basis.

Per the CUP POR recommendations, it has been determined that in the future, the steam distribution may be replaced with a heating hot water distribution system with building conversions to hot water from steam. For those building conversions, process steam needs will eventually be handled locally. This conversion will allow for a more efficient system long-term, and for a future reduction of fossil fuel use. Due to this future system

J u n e 2 0 2 4 1 1 conversion, the pumped condensate piping in the new distribution is sized to match the size of the high-pressure steam line. See details on pipe sizing methodology further in this document.

See drawings M-1.0 and M-2.0 for the overall layout of the proposed distribution network and pipe sizing.

These drawings show the location of the limited walkable tunnel. For alternate 1, these drawings are to be utilized but the tunnel shall be removed, and pipes shall be direct-buried. See drawings M-3.0 and M-3.1 for details of the thermal utility piping.

Walkable Tunnels

The following images depict three-dimensional views of the tunnel and plan and sections views.

Exhibit 1: Tunnel Section

Exhibit 2: Tunnel Plan View

Walkable tunnel sections shall have an estimated interior dimension of 15’-0” wide by 11’-0” tall depending upon pipe size. There shall be building takeoff valve vaults along the walkable tunnel for future and existing buildings. The size of these vaults will vary depending upon if the take-off is from the side of the chilled water piping or the steam piping as well as the pipe size. The valve vaults interior dimension is estimated at 31’-0” wide by 13’-0” long at 14’-6” tall where take off are from the steam side. The valve vaults interior dimension is estimated at 24’-0” wide by 13’-0” long at 14’-6” tall where take off are from the chilled water side.

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Where tunnels have tees and crossing junctions of the tunnel, the interior dimension shall increase to 35’-0 wide by 35’-0 long by 14’-6” tall. Manhole extensions to grade shall include 6’-0 by 6’-0 risers with 36” manhole covers.

Walkable tunnels shall include the following auxiliary utilities: ventilation, lighting, fire alarm, and drainage.

There shall be a drainage channel (cast in the tunnel floor) to low points and gravity drained or pumped.

Further auxiliary utility requirements within the tunnel including fire protection to be determined by design team providing construction documents.

Exhibit 3: Tunnel 3-D Perspective View

Exhibit 4: Tunnel 3-D Perspective View – View Though Walls

Exhibit 5: Tunnel 3-D Perspective View - No Roof or Manholes

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Exhibit 6: Plan View Tee Junction

Exhibit 7: Plan View Take-Off Steam Side Exhibit 8: Plan View Take-Off Chilled Water Side

Non-Walkable Pipe Tunnels

An alternate to walkable tunnels is non-walkable concrete encased pipe tunnels. These are estimated to be 14’-0 wide by 6’-0 tall. Junctions and valve vaults are expected to be walkable of comparable size to that of walkable tunnels.

Direct-buried Pipes

For direct-buried piping there shall be manholes at junctions with isolation valves for the steam and condensate systems. For chilled water direct-buried piping provide valve boxes of three-piece cast iron type with shaft and valve wrenches with T handle extension or as an alternate, contactor to explore providing a 4- 6” Schedule 40 PVC pipe instead of cast iron box.

Pipe Junctions

The junctions and take off valves to existing and future buildings will be sizes such that the condensate return line is equal in size to the steam line to allow for future conversion. The pipes will then transition in size after the junction to connect to the existing building distribution steam and condensate pipe sizes.

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At locations with changes in elevation in the steam distribution system, at building takeoffs, and approximately every 300 feet in pipes, there will be high pressure condensate drips. These drips shall be piped together in parallel to the steam and pumped condensate lines to flash tanks and then pumped into the main pumped condensate system. The exact routing and location of these high-pressure condensate lines and pumping station assemblies shall be determined during the detailed design of this project. In locations with tunnels, these systems shall be located within the valve vaults and at major junctions and crossings. Where direct-buried piping is employed, high pressure condensate may be either routed into building mechanical rooms to be flashed and pumped, or vaults with manholes shall be designed for the required pumping station locations. Contractor to consider use of prefabricated manholes for centralized flash and pump locations.

Schedule and Phasing

Drawings M-1 and M-2 indicate general timeframes for future buildings that may impact the schedule. The south leg of the campus distribution is of immediate priority and will be built first. On the utility plans the solid piping (blue for chilled water and red for heating system) are the initially required pipes for the total system with dashed piping indicated for future buildings. The piping noted in dashed solid green is for a supplemental redundant loop to make the overall system more resilient and to reduce outages in cases of utility disruptions in the system. This green piping will be the final piping installed in a phasing plan. Further the redundant pipe along research drive will not be installed until the rest of the system is operational to allow the demolition of the existing thermal utilities prior to the installation of the new pipes.

The civil plans will address the specific phasing of the installation of all utilities. When the contractor plans the installation, it is important that the following items remain accessible during constructions:

1. Fire Department Access to Buildings and access to building Fire Department Connections

2. Access to Fire Hydrants

3. Occupant access to the public way for egress of occupied buildings

Chilled Water

Chilled water pipes will be sized for a maximum pressure drop of 4 feet of head loss per 100 feet of pipe and a maximum velocity of 12 feet per second with a temperature differential of 13°F.

Pipes shall be ASTM A53 Grade A or B, Type E or ASTM A106, Grade B, standard weight black steel. Direct-buried pipes shall be a pre-insulated system utilizing polyurethane foam insulation and HDPE outer protective insulation jacket applied on the insulating foam. Pipes within Tunnels shall be field insulated with Phenolic Foam or Cellular Glass insulation and jacket as specified. No grooved joint piping will be allowed.

Direct-buried piping expansion shall be via pipe expansion loops. Where expansion joints are required in tunnels, self-lubricated slip-type joints designed to permit injection of packing under full line pressure will be used.

High Pressure Steam

High pressure steam size is based upon the greater of the size required for steam or heating hot water. The sizing of new pipes is based upon the load calculations performed and a comparison of existing pipe sizes.

For the high-pressure steam and pumped condensate pipe sizing, the following pipe sizes were compared, and the largest size was used to size the pipe mains:

• Size required based upon total steam loads.

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• Size required with heating hot water excluding building process steam loads and humidification loads.

The High-pressure steam piping size criteria is to maintain velocities at a maximum of 8,000 and 10,000 feet per minute with a maximum pressure drop of 0.5 psi of steam pressure per 100 feet of pipe at 150psig. Most main pipes are sized at less than 0.3 psi of pressure drop per 100 feet of pipe, as the total system length from the CUP is approximately 6000 feet. For heating hot water, the pipe size is determined based upon a 40°F temperature differential between the supply and return pipe with a maximum pressure loss of 4 feet of head loss per100 feet of pipe and a maximum velocity of 12 feet per second.

High pressure steam piping shall be ASTM A106 Grade B Schedule 80, extra strong, carbon steel. Direct-buried pipes shall be factory pre-insulated, Class A drainable, dryable system consisting of carrier pipes, insulation, air space, inner jacket of 10g steel, aerogel insulation and outer jacket. Pipes located within tunnels shall have field applied insulation of mineral wool. Rigid Fiberglass may be used in walkable tunnels in leu of mineral wool where tunnels are conditioned.

Direct-buried piping expansion shall be via pipe expansion loops. Where expansion joints are required in tunnels, self-lubricated slip-type joints designed to permit injection of packing under full line pressure will be used. In direct-buried pipe runs where expansion loops are unable to be utilized due to other nearby utilities, slip-type joints shall be utilized in manhole locations.

Pumped Condensate

Pumped condensate is sized to be equal to the size of the high-pressure steam line, to allow for future conversion to a heating hot water system.

Pipes shall be ASTM A312.A312M, TP 316 Schedule 40, seamless stainless steel or Schedule 160, carbon steel. Direct-buried pipes shall be of the same construction as for high pressure steam pipes except for the carrier pipe. Pipes in tunnels shall utilize the same type of insulation as the high-pressure steam pipes.

Direct-buried piping expansion shall be via pipe expansion loops. Where expansion joints are required in tunnels, self-lubricated slip-type joints designed to permit injection of packing under full line pressure will be used. In direct-buried pipe runs where expansion loops are unable to be utilized due to other nearby utilities, slip-type joints shall be utilized in manhole locations.

High Pressure Condensate

High pressure condensate shall be sized as necessary per the sizing criteria of Table 21 of ASHRAE Handbook Fundamentals – 2013, Chapter 21. The Capacity of Table 21 is based on standard weight and shall be adjusted to extra strong weight.

Pipes shall be ASTM A312/A312M, TP 316 Schedule 40, seamless stainless steel or Schedule 160, carbon steel. Direct-buried pipes shall be of the same construction as for high pressure steam pipes except for the carrier pipe. Pipes in tunnels shall utilize the same type of insulation as the high-pressure steam pipes.

System Monitoring

The new thermal utility distribution system shall include leak detection to improve overall system maintainability. System shall include leak detection in pre-insulated direct-buried pipe system and at locations within the utility tunnels along with segment flow meters. As an enhancement, contractor to provide an option for segment motorized valves. Flow meters and motorized valves would be located at major junctions at

16 Metropolitan Architects and Planners, Inc. | Affiliated Engineers, Inc. | Alpha Corporation locations indicated by NIST during the design phase of the project. Control wiring pathways would run within the tunnels where provided, and in separate conduit pathways parallel to the pipes where direct-buried.

Design and operation of these valves and meters to be further clarified by contractor with NIST in design phase of project.

Electrical Utility Distribution

A. Existing Conditions

Building 306 houses the electrical service to the campus. The electricity needs of the campus facilities are served by a four-bus, solidly-grounded 15 kV substation. The substation is fed from three 69 kV PEPCO utility feeders. The feeders connect to three PEPCO-owned 69 kV to 15 kV step-down transformers rated 37.5 MVA each which serve other customers in addition to NIST.

The Main-Tie-Main-Tie-Main-Tie-Main-Tie switchgear has eight circuit breaker cubicles on the A bus (two spares), eight circuit breaker cubicles on the B bus (two spares), seven circuit breaker cubicles on the C bus (one spare), and six circuit breaker cubicles on the D bus (one spare). The buses are connected in a ring configuration, with tie breakers A-B, B-C, C-D and D-A.

Spot network systems, such as the system utilized at NIST, are designed to provide highly reliable low-voltage service to a building. In this system, a fault or failure of any one transformer or one campus/utility feeder will not result in any interruption of service to a building. Only a fault or failure of two transformers or two campus/utility feeders will result in a loss of service to part of the building being served. This is a very robust and reliable normal power distribution system that also provides flexibility for future growth.

The majority of buildings on the campus are served by three 15 kV feeders terminating at separate 480/277 volt and 208/120 volt substations within the individual buildings with the remaining buildings either served with two 15 kV feeders or served via low voltage from a nearby building.

The campus buildings that house the general-purpose laboratories are all fed from the 15 kV campus distribution system in the following configuration.

Campus Feeder Nos. FA-2, FB-2 and FD-2 serve Meteorology Building 220, Chemistry Building 222 and Technology Building 225 as well as other campus buildings.

Campus Feeder Nos. FB-3, FC-3 and FD-3 serve Polymer Building 224, Building Research Building 226, Physics Building 221 and Materials Building 223 as well as other campus buildings.

The campus buildings that house the Advanced Measurement Laboratories are all fed from the 15 kV campus distribution system in the following configuration. Campus Feeder Nos. FA-7, FB-7 and FC-7 serve Nanofabrication Facility 215, Meteorology East Building 218, Meteorology West Building 219, Instrument East Building 216 and Instrument West Building 217.

Seven feeders are dedicated to medium-voltage chillers in the Central Plant, Building 302.

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The campus distribution to all campus facilities consists of an underground concrete ductbank system with radial feeders tapped to the spot network configuration building services. The feeders which make up a triplet serving a group of buildings are run through the same ductbank, limiting the redundancy available. There are no isolation switches in the system, further reducing the maintenance options available to NIST. The current manholes contain multiple feeders and there are strict policies in place to prevent working in a manhole if it is energized. Therefore, all feeders in a manhole must be deenergized if work is required on one of them.

When the campus was built, there were spare ducts in the ductbanks. However, at this point several ducts have collapsed and others have become unusable because the cable pulling lubricant used to pull abandoned cables into the duct has turned to glue over the ensuing decades, making it impossible to remove the cables and reuse the ducts.

When the campus was built, all of the distribution feeders were installed as paper-insulated, lead covered (PILC) medium voltage cable with splices at each building. There is no way to separate a building from the feeder or to isolate a faulted length of cable. The current industry standard is EPR insulation and load break disconnects at each building and at various points along the radial feed. Replacing the aging existing PILC cables is within the scope of this current effort.

With the installed utility capacity of 87.7 MVA from the three PEPCO 37.5MVA, 69kV-13.8kV transformers, the available reliable capacity of the substation is 75 MVA based on N+1 equipment redundancy. Based on the metering data available, the peak plant campus load is about 38 MVA. The capacity of the medium voltage feeder system to deliver the capacity to new load additions is taken into consideration for the new feeder distribution based on the zones of development, projected load density and the capacity of distribution system.

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B. New Medium Voltage Distribution

The new campus distribution for buildings will be covered by seven new MV distribution feeders installed in the lapse of five phases. All distribution feeders will be installed in concrete-encased duct banks. Cables to be 500kcmil, 15kV, MV-105 EPR 133% BIL with an ampacity of 500A.

Lateral feeders to existing buildings will be replaced and then connected to the new distribution feeders. All buildings will be connected in a N+2 configuration for redundancy. In addition, under phase 4 with the construction of the new substation, an extra level of redundancy is proposed and extend the main distribution feeders to be also fed from this new substation.

Detailed phasing notes are included in the electrical drawings. The intent is to minimize power disruptions to the campus. The summary tables below represent the new campus electrical distribution from the existing substation in Building 306 after all phases are complete.

SP 4A SP 4B FA-105 5A FA-103 5B FA-104 6A FA-102 6B FA-107 7A FA-106 7B

BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD

220 1278 231 627.6 103 15.6 215 1011.5 CUP (13.8KV) 4455 CUP (5kV) 2133

221 1455.8 233 911.5 228 2500 216 923.9 302PUMP 498

222 613.1 301 352.4 224 983.2 217 1130.8 CT 1071

223 911.5 304 435.7 226 891.5 218 1147.9 101 991.3 242/243/244 4800 225 983.2 219 900.5

101Add 1947 227 1118.9 230 354.5 221Add 92.7 226 Add 92.4 222Add 92.7

FEEDERS - Phase 5

A BUS

SP 11B SP 11A FB-101 10B FB-105 10A FB-103 9B FB-104 12A FB-107 12B FB-106 13B

BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD

202 739.1 220 1278 231 627.6 103 15.6 CUP (13.8KV) 4455 CUP (5kV) 2133

235 91.7 221 1455.8 233 911.5 228 2500 302PUMP 498

205 147.2 222 613.1 301 352.4 224 983.2 CT 1071

206 137.6 223 911.5 304 435.7 226 891.5

245A/B/C 1395.8 101 991.3 242/243/244 4800 225 983.2 245H 833 101Add 1947 227 1118.9 245D 848 221Add 92.7 226 Add 92.4 245E 132.9 222Add 92.7

209 332.6 104/326 750

B BUS

SP 19A FC-101 19B FC-102 20A FC-105 20B FC-104 21A FC-107 21B FC-X 22B

BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD

202 739.1 215 1011.5 220 1278 103 15.6 CUP (13.8KV) 4455 COGEN

235 91.7 216 923.9 221 1455.8 228 2500 205 147.2 217 1130.8 222 613.1 224 983.2 206 137.6 218 1147.9 223 911.5 226 891.5

245A/B/C 1395.8 219 900.5 101 991.3 225 983.2 245H 833 230 354.5 101Add 1947 227 1118.9 245D 848 221Add 92.7 226 Add 92.4 245E 132.9 222Add 92.7

209 332.6 104/326 750

C BUS

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C. New Substation (SS2)

A new substation is proposed to be built under phase 4 to accommodate the buildings planned to be constructed during the 30-year NIST plan. A 3000A, 3PH, 3-wire, 13.8kV switchgear. A Main-Tie-Main-Tie- Main-Tie-Main-Tie switchgear with similar configuration as the existing switchgear in Building 306 will provide power for two additional distribution feeders. This substation will have enough sections to provide a closed open loop distribution for the two new distribution feeders. Additionally, this substation will be capable of feeding the other five main distribution feeders for flexibility of maintenance and redundancy. Further coordination with the power company will be necessary to accommodate this new substation. Drawing 301b shows the new substations configuration and connection to the campus electrical distribution.

Per discussions with NIST high voltage group personnel, it was determined that in the new distribution feeders from A, B, C, and D busses would be run in separate vaults/manholes so that a single feeder serving a group of buildings could be taken out of service without requiring that the buildings have an outage. Therefore, each building/group of buildings will be fed from three distribution manholes (vaults) in which load break buses and connectors will be installed. Even though NIST policy requires that the feeders be deenergized before working in the vault, the vaults will be sized to allow space to operate a hot stick withing the vault.

Distribution manholes/vaults are to be 12ft x 14ft in size, whereas pass-through-only manholes are to be 8ft x 6ft. Details on these vaults, manholes, and feeder connections are provided within the electrical drawings.

SP 26B FD-101 26A FD-106 25B FD-103 25A FD-107 24B FD-102 24A

BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD BLDG LOAD

202 739.1 CUP (5kV) 2133 231 627.6 CUP (13.8KV) 4455 215 1011.5

235 91.7 302PUMP 498 233 911.5 216 923.9

205 147.2 CT 1071 301 352.4 217 1130.8

206 137.6 304 435.7 218 1147.9

245A/B/C 1395.8 242/243/244 4800 219 900.5 245H 833 230 354.5 245D 848 245E 132.9

209 332.6 104/326 750

D BUS

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Phasing and Sequencing

Phasing and sequencing must consider Fire Department access to buildings, access to fire hydrants, access to…