RFI_MTE_230kV_Repair_-_Industry_Day_1.pdf

Industry Day Notification Scope:

NOTICE: This is not a solicitation but rather an Industry Day Notification to determine potential sources for information and planning purposes only. A separate Small Business Sources Sought has also been posted under this same solicitation number, 140R6023R0021, for the Mt. Elbert 230kV Cable Repair Project ONLY to determine any potential small business sources.

The purpose of this Industry Day Notice and the Industry Day itself is to conduct market research to determine if capable and responsible sources exist to assist in determining acquisition strategies.

The proposed North American Industry Classification Systems (NAICS) Code is 22111 (Electric Power Generation ).

Projected Requirement Details:

The Bureau of Reclamation (Reclamation), Missouri Basin (MB) Region – Regional Office desires to engage the extra high-voltage underground power transmission cable industry to provide a clear, concise, fair, and reasonable approach to the procurement strategy regarding the Mt. Elbert 230kV Cable Repair Project.

Work is located at the Mount Elbert Powerplant located approximately 20 miles south-southwest of Leadville, Colorado in Lake County, via Highway 24 (US 24) and Colorado Highway 82 (CO 82), 24 miles north-northwest of Buena Vista, CO via US 24 and CO 82, and 144 miles from Denver International Airport via Interstate 70 (I-70), US 24 and CO 82.

The plant entrance is on state road CO-82 about 4.6 miles west of US-24.

Coordinates: 39.094796, -106.354775

Project Background:

The Mt. Elbert Pumped Storage Powerplant is situated at approximately 9,200 ft. elevation on the edge of Twin Lakes approximately 15 miles south of Leadville, Colorado. The power generated at Mt. Elbert derives from water originally pumped from Twin Lakes, which acts as the Mt. Elbert afterbay, and also from supplemental water delivered from Turquoise Lake to the forebay. Two pump-generators are housed in the powerplant.

The Mt. Elbert powerplant and switchyard is electrically connected through a set of 230 kilovolt (kV) direct-buried, self-contained fluid-filled, oil-filled paper insulated power cables. Each unit transformer is connected to the switchyard through these cables. The self-contained, fluid-filled, cables originate at the switchyard and enter the ground through the Switchyard Cable Vaults.

They run underground, down the hill to the Powerplant Cable Tunnel. They are then carried through the tunnel to the Transformer Service Deck where they are terminated near the transformers. There are two cable circuits, each cable circuit consists of three single-phase cables for a total of six individual cables.

Project Scope:

An independent contractor performed extended diagnostic tests on the 230kV underground cables in 2019. The testing indicated deficiencies regarding several components associated with the cable sheath (jacket) that require correction. Reclamation electrical engineers performed two rounds of follow-up diagnostics in 2019 and 2020 to better define and identify these deficiencies.

Testing has identified that it is not possible to confirm the root of the deficiencies without some form of excavation, coinciding with further testing, and repair. It is anticipated to perform partial excavation(s) and interim testing to fully investigate the issues. There will be a discovery period to ultimately define the full scope of work. The engineers reports and data will be made available during the Industry Day meetings for discussion purposes. It is highly encouraged for the contractor to bring engineering personnel to this meeting. USBR test engineers will be available for technical discussions.

A high-level overview of the issues:

1. Several cable shields exhibit low-resistance to ground (excavate, investigate, repair).

2. With the SVLs disconnected from the cable shields, the shields still present low insulation resistance with respect to earth ground. This could indicate a problem:

a. Just inside the SVL water-tight enclosure at the linking cable entry point or the cable terminations inside the water-tight enclosure.

b. With the linking cables connecting the SVLs to the buried cable splice(s).

c. With the buried splice(s) at the linking cable entry.

d. With the cable shields anywhere along the cable route.

e. With any combination of the above (a. – d.)

3. Several of the cable Sheath Voltage Limiters (SVLs) are damaged. These devices are potted into a water-tight enclosure and are not field-replaceable. A set of new, field-serviceable/replaceable SVLs with new water-tight enclosures are required (excavate, investigate, replace).

This type of repair will require a contractor to perform excavation, investigate the low resistance of the cable shield-to-ground issue, then be prepared to execute any type(s) of necessary repair depending on the findings. This could yield a wide scope of work from simply replacing the SVLs and water-tight enclosures to possibly excavating the cable splices and making additional splices to repair the oil-filled cable. If the existing cable splices are the source of the low shield-to-ground resistance and are damaged beyond repair, the contractor may have to perform a double-splice repair(s) using spare on-site cable and splice kits. The Government has spare cable onsite that would be considered Government Furnish Equipment along with only two cable splice bodies. Though the spare cable and splices are believed to be in useable condition the viability of the spare cable and splice bodies must also be evaluated by the contractor before use.

Depending on the scope of work (discovery) additional splices may need to be furnished by the contractor.

Strategy Overview/Schedule of Projected Events:

The purpose of this Industry Day Notice and the Industry Day held at Mt. Elbert Pumped Storage Powerplant near Leadville, CO on September 13, 2023, is to gather industry information from interested parties, which is deemed essential as part of Reclamation’s collaborative planning process for procurement of Mt Elbert 230kV Cable Repair Project. A brief estimated milestone schedule (subject to change) has been provided below for the BOR planned procurement strategy for this project as a basis for procurement planning:

• Pre-solicitation with Sources Sought and RFI/Industry Day Details Issued – August 13,

• Industry Day– September 13, 2023

• Q&A Posting – Responses to Industry Day Questions Projected to be Posted – September 30, 2023 (These responses will consist of the Government answers to questions received during the one-on-one meetings during Industry Day.)

• Synopsis to Industry of Upcoming Solicitation for the project. Projected to be Posted – December 2023

• Request for Proposal (RFP) Projected to be Issued – January 2023

• Project Award and Notice to Proceed Issued Projected – Spring 2024

• Contract Substantial Completion with Delivery Projected – June 2024

• Contract Final Completion after Commissioning Projected – July 2024

Projected Future Project

- Protection and Annunciation - TBD

Industry Day Details:

INDUSTRY DAY SCHEDULE

Wednesday, September 13, 2023 8:00 am – 8:45 am: Registration 9:00 am – 10:00 am: Presentation of project scope and review of Job Hazard Analysis 10:15 am – 11:45 am: Site visit at primary location of work (short drive from plant) 11:45 am – 12:00 pm: Return to powerplant 12:00 pm – 1:00 pm: Government Break / Lunch 1:00 pm – 5:00 pm: Individual Meetings

To register to attend the Industry Day on September 13, 2023, please RSVP to Ms.

Jessica Busman at jbusman@usbr.gov by September 1, 2023 NLT 2PM Mountain mailto:jbusman@usbr.gov

Time (UTC-7:00). The Project Presentation does have capacity limitations so each contractor is limited to two spots and will be reserved based on first come request. After the limit is reached virtual option will be offered. To schedule an individual meeting on September 13, 2023, please RSVP and provide the Requested Information below to Ms.

Jessica Busman at jbusman@usbr.gov by September 1, 2023 NLT 2PM Mountain Time (UTC-7:00). Each one-on-one appointment will be 45 minutes in duration. These will be scheduled based on first request.

For Construction Firms: if you prefer to schedule a one-on-one appointment, please provide evidence of bonding capability of at least $1 million. Also, please provide a synopsis of the possible teaming agreement you have in mind (or state teaming is TBD).

• The Government is interested in all business sizes including small businesses, such as 8(a), Service-Disabled Veteran Owned, Hubzone, and Women-Owned small business concerns. The government requests that interested parties respond to this notice if applicable and identify your business size status to the identified NAICS code.

Additionally, please provide any anticipated teaming arrangements, along with a description of similar services offered to the Government and to commercial customers for the past seven years.

• Any responses involving teaming agreements should delineate between the work that will be accomplished by the prime and the work accomplished by the teaming partners.

Request for Information

Information/Input Requested:

BASED ON THE RESPONSES TO THIS NOTICE/MARKET RESEARCH, THIS

REQUIREMENT MAY BE SET-ASIDE FOR SMALL BUSINESSES OR PROCURED

THROUGH FULL AND OPEN COMPETITION.

Submission Instructions for RFI Questions Listed Below: Interested parties who consider themselves competent to perform the above-listed qualification and/or production are invited to submit a response to this Notice by September 22, 2023

Responses are requested but not required. No award will be made off the responses provided as this is not a solicitation notice. The provided information may or may not affect the projected acquisition strategy. If providing information please keep the responses short, concise, and to the point. Only provide expanded information if the providing entity finds the information valuable. Lengthy, verbose responses are not required or desired. Please limit the total response to no more than 5 pages.

Questions Regarding the Mt. Elbert 230kV Cable Repair Project:

1. Is there a desired procurement process from the industry (IFB/RFP)?

2. Do you have concerns with procurement of spare cable or cable splices for cable sheath ground conductors? What would be the expected lead time for these devices (submittal approval to arrival at the site)?

Project Size and Schedule:

1. Does anyone in the industry have concerns about the size of the project? The scope may expand depending on findings during the repair process (see #2 below).

2. Does anyone have concerns about having optional bid items that would be executed based on findings and test results?

3. What would be an estimated schedule for execution of this work?

Site Conditions:

1. Does anyone have concerns about excavation and electrical work being performed at this location during May and June?

2. Does anyone have concerns about site access?

3. Does anyone have concern about managing the public’s access and safety to the worksite?

4. Does anyone have concerns about ability to excavate to depth of the 230kV cables without damaging them and the other infrastructure?

a. Please note: Two 500 MCM bare copper grounding conductors, 13 low-voltage control cables, and one 5 kV power cable run along the same trench above the 230kV cables (refer to Attachment #1, Figure 4).

Technical:

1. Do contractors have current experience working with 230kV paper-insulated, oil-filled cables of this design?

2. How many paper-insulated oil-filled cables does your organization repair each year?

3. Should cable splices be necessary, would the contractor choose to use the existing spare cable and splice bodies or possibly repair with a hybrid oil-paper-to-polymer cable splice that ensures oil flow through the hybrid splice?

4. What excavation method would be used for this type of work? Does the method depend on the type and depth of excavation?

5. Would excavation be sub-contracted or performed by the contractors own personnel?

6. Does excavation equipment have to be rented or is it owned by the contractor?

7. Snow and water ingress into the new SVL enclosures is a major concern. How can the new SVL boxes be installed in such that they are field serviceable (individually replaceable) yet contained in a water-tight enclosure? Note: the SLV enclosure must also be designed such that they prevent the public from access.

8. Will new concrete vaults be necessary?

9. If the linking cables from the buried splice to the SVL enclosures are the cause of the low resistance, would it be possible to replace just the linking cables without replacing the main cable splices?

10. Would the contractor prefer to perform the investigative testing once excavation activities begin, or would they prefer the USBR test engineers perform this task in coordination with their work?

11. Is there a better method to protect the cable sheaths (jackets) other than the existing SVLs?

12. Is there a better way to perform this work? How would the contractor approach these issues?

Questions Regarding the Mt. Elbert Protection and Annunciation Project:

1. Would as updated as built drawings make this easier for a construction firm?

Attachment(s)

• Attachment #1 – 230 kV Cable Technical and Installation Details

• Attachment #2 – Directions to Industry Day at Mt. Elbert Pumped Storage Powerplant

• Attachment #3 – Protection and Annunciation * Not included* email jbusman@usbr.gov to request the draft SPECS

Attachment #1 – 230 kV Cable Technical and Installation Details

The Mt. Elbert powerplant and switchyard is electrically connected through a set of 230 kilovolt (kV) direct-buried, self-contained fluid-filled, oil-filled paper insulated power cables. Each unit transformer is connected to the switchyard through these cables. The self-contained, fluid-filled, cables originate at the switchyard and enter the ground through the Switchyard Cable Vaults.

They run underground (direct buried), down the hill to the Powerplant Cable Tunnel where they pass into a tunnel leading to the Transformer Service Deck. They are then terminated near the transformers. There are two cable circuits, each cable circuit consists of three single-phase cables for a total of six individual cables. No spare cables are installed. The cables are buried approximately four to five feet under the surface (Figure 6).

The elevation differential between the powerplant and switchyard terminations is approximately 630 ft., and the overall length of the cable path is approximately 6,340 ft. Oil pressure at the switchyard and powerplant ends of the cable is approximately 14 and 252 pounds per square inch (psi) respectively. Total oil volume per phase is approximately 1,673 gallons. The paper-insulated copper-conductor cables are impregnated with mineral oil and protected by a 138-mil thick corrugated aluminum shield with an overlaid 157-mil thick polyethylene sheath (jacket) (Figure 7). The cables were manufactured by Furukawa Electric Inc. and put into service around May 1981. The are internally pressurized with mineral oil to increase the dielectric strength of the paper insulation, suppress ionization in the insulation, and impedes moisture ingress if there is a leak in the jacket and protective aluminum shield. The fluid pressure is maintained through a hollow, perforated steel-core in the center of the copper conductors. The hermetically sealed aluminum sheath contains cable pressure, prevents moisture entry, carries fault currents, and provides mechanical protection for the direct-buried application at Mt. Elbert.

During construction, all six cables at Mt. Elbert were intentionally spliced approximately half-way between the powerplant and switchyard. The cable splices are buried and are inaccessible without excavation. At the splice location, the aluminum shields are intentionally made discontinuous between the powerplant and switchyard ends to prevent circulating current losses due to normal line-current, fault currents, and other potential circulating currents between the switchyard and powerplant. At the buried splice location, each of the six cable shields are bonded to an individual high-voltage cable (linking cable) that is believed to be a non-shielded type. These non-shielded ‘linking’ cables connect the 230kV cable shield (buried in the splice) to the ground surface. At the surface these linking cables enter a small partially buried concrete vault (Figure 1 and Figure 2). The linking cables continue through the concrete vault wall and into a water-tight metal enclosure (link-box) (Figure 3). Inside the link box they are each terminated to one terminal of a Sheath Voltage Limiter (SVL) (Figure 4). The SVLs and terminals of the linking cables are housed inside a waterproof (epoxy-potted) grounded metal enclosure. There are two concrete vaults and two water-tight enclosures, one for each cable circuit. Each enclosure contains six SVLs (12 total). The metal enclosure is intended to be a water-tight enclosure contained within a small non-waterproof concrete vault. The purpose of the SVL is to limit transient voltages imposed on the polyethylene cable jacket during lightning strikes or other fault conditions. The concrete vaults are located along the direct-buried cable route approximately 200 yards from the forebay gatehouse (refer to Figure 1 and Figure 2).

Figure 1.— Concrete vaults for Unit 1 and Unit 2 cable splices. Forebay in background.

Figure 2.— Removing the concrete vault lid.

Figure 3.— Water-tight SVL box and lid for Unit 2 cables shown inside concrete pit.

Figure 4.—Water-tight SVL box open showing SVLs potted in black compound (unit 2 SVLs shown).

Figure 5.—Cross-Section of the 230kV Cable Installed at Mt. Elbert

Figure 6.—230kV cable trench cross-section

Figure 7.—Cross-Section Drawing of Cable

Table 1: 230 kV Cable Specifications

Parameter Quantity / Description Notes Year Placed In-Service 1981 Manufactured around 1977 Rated Voltage (kV) 230 Conductor Size (MCM) 600

Insulation Thickness (mils) 760 (average), 710 (minimum)

Carbon paper layers over conductor (mils) 10 Insulating paper tape layers (mils) 750 Nominal thickness of insulating paper tape (mils) 4, 5, and 6

Basic Switching Level (BSL, kV) 840 200 x 2000 µs wave shape

Shielding

Carbon paper tape and aluminum paper tape interlaced with carbon paper tape

Aluminum Protective Shield (mils) 138 sine-wave corrugated aluminum tube

Basic Impulse Insulation Level (BIL, kV) 1,050

Nominal Oil Pressure (psi) 14 (switchyard) 252 (powerplant)

Oil Quantity (gal./phase) 1,673

Number of Splices (buried – inaccessible) One per phase, mid-run, each cable

2 additional splices: Unit 2 Phase A, Unit 2 Phase B (Buried – inaccessible)

Insulating Oil Type Mineral Oil AC cable impedance (Ω/1000 ft.) 0.0182 DC cable resistance (Ω/1000 ft.) 0.0223 Capacitance (µF/1000 ft.) 0.0668 Conductor Resistance (dc, Ω / 1000 ft.) 0.0223 Shield Resistance (dc, Ω / 1000 ft.) 0.00908 Continuous Current Rating (A) 322 / 380 / 389 / 410 70 °C / 85 °C / 90 °C / 100 °C

Attachment #2 – Directions to Industry Day at Mt. Elbert Pumped Storage Powerplant

Address:

Bureau of Reclamation Mt. Elbert Power Plant

5583 East Highway 82

Twin Lakes, CO 81251

From Leadville, CO (approximately 23 miles):

Take HWY 24 south, approximately 15.1 miles to HWY 82 west toward Aspen. Follow HWY 82 for approximately 4.4 miles. The powerplant is located on the south side of HWY 82.

From Buena Vista, CO (approximately 27 miles):

Take HWY 24 north, approximately 19.2 miles to HWY 82 west toward Aspen. Follow HWY 82 for approximately 4.4 miles. The powerplant is located on the south side of HWY 82.

Accommodations and basic services are available at either location above.