Technical_Bidder_Inquiries_for_Radford-Atch_27.pdf

1. Section: 01 10 00 W91236-15-R-0008 Page 206 mentions in

(vii) Flow instruments

(A) Flows for water, steam, oil, and gas shall be measured by means of a DP-type element. Magnetic flowmeters, turbine flowmeters, ultrasonic flowmeters, and vortex or coriolis flowmeters may be used where DP flow elements are not appropriate. What new flowmeters will be required?

Flow Meters shall be provided in accordance with requirements found in the RFP, and as required by UFC and UFGS. As examples and without any any limitation to the RFP requirements or restriction to metering requirements identified in various paragraphs of Section 01 10 00 -herein attention is called toward:

*Metering of Natural Gas – refer to 3.11.5.2.b *Metering of Steam and Boiler Feedwater - Boilers and HRSGs Three Element Control (3.11.5.4 nn and 3.11.5.8 ddd) *Metering Requirements for Boiler Chemicals System -refer to 3.11.5.13 *Metering of Steam Headers (3.11.5.14 and 3.11.5.12) *Metering of Fuel Oil (3.11.5.8.5.x) *Metering of Water to Softener (3.11.5.19) *Metering of Potable Water (6.6.1.6)

2. Section: 01 10 00 W91236-15-R-0008 Page 206 - Is there a flowmeter Schedule Available?

No. This is a DOR (designer of record) responsibility.

3. On pages 10-15 of 30 (Section 5.2.1) of Amendment 3, there are numerous references to Specification Section 01 91 00.00 40 (Performance Testing, Inspection and Commissioning). This specification section does not exist within all the documents that were released to us. Please provide this specification section.

Delete references to Section 01 91 00 00 40. Commissioning requirements are identified in Section 01 91 00.80.

4. Page 9 of 35 reference SCR for "Proposed Betterments". When reviewing Section 00 73 00, we note that while there are Special Contract Requirements, there is not a specific reference to "Proposed Betterments". The Special Requirements included with the RFP reference:

8. Basis for Payment and Cost Loading and a Cost Loaded Project Schedule

9. Special Provisions for Utility Usage

10. Small Business Participation Plan

Section 00 73 00 should not have been the reference in Paragraph 5.1 on page 9 of 35 in amendment 0003.

This has been corrected with amendment 0010 dated 4 Sept 2015. The correct reference for proposed betterements is paragraph 5.4.1.4 of Section 00 22 20.

5. The scope states that "The Control Room shall have direct line-of-sight to all major plant equipment – the CTG/HRSG combination, the boilers, and the BPSTG through windows that extend from workstation tabletop height to the ceiling. The Electrical Switchgear Room and Chiller Room shall be enclosed and are therefore not required to be visible directly." And "The Control Room shall be raised above the plant floor in order to establish direct visual surveillance. The elevation of the Control Room floor shall be determined on the basis of a clear line-of-sight over near plant equipment for observation of equipment beyond."

The Control Room is also part of the Support Spaces portion of the building that requires STC and Fire-rated construction to separate these personnel spaces from the equipment spaces. Would it be acceptable to the owner to provide direct line-of- sight for all equipment through the use of CCTV cameras and monitors in the Control Room instead of the prescribed adjacent elevated room with direct windows?

The advantages would be that the costs associated with the STC and Fire-rated window glazing would go away, and the overall STC rated wall construction would work better for the personnel areas as the window glazing is the weakest sound leakage point, the Control Room could better meet ADA requirements if not elevated, and during emergencies the Control Room personnel are better protected from the fire source with a wall than glazing - with a faster path of egress if it is not a raised room.

The control room requirements will remain as currently specified.

6. The Scope requirements state that roof must be sloped and flat roofs are not acceptable; and that internal

Attachment 25 drainage is not allowed so all roofs must be sloped to drain to the edges. The Scope also describes that a roof hatch is not acceptable as the primary means of accessing the roof, and instead a sheltered stairway through the roof assembly for access onto a sloped metal roof is required. We believe that a stairway through the roof stepping out onto a sloped roof assembly would not be desirable. Please verify that roof access (including the enclosed stairway from plant floor to rooftop level as described in Scope) is not required if there is no roof-top equipment.

One of the concerns for roof access is the ability to place maintenance equipment and tools at the top landing and under shelter while services are being performed on the roof. Although some mechanical equipment might be offset from the roof to other locations, penetrations, emissions sensor access, future GFGI equipment placement, and general roof maintenance needs cannot be avoided. The client has articulated a specific interest in a sheltered landing at the top of a roof access stairway for these purposes

7. Drawing M-610 shows 275 PSI export steam flow as 251 MLB/Hr and the 40 PSI export flow as 300

MLB/Hr. This totals 551 MLB/Hr which exceeds the specified firm design total of 460 MLB/Hr. Can it be confirmed that the 275 PSI and 40 PSI peak flows are not coincident and the combined firm export design basis is 460 MLB/Hr?

Peak demands for 275 psig steam and 40 psig are not to be conisdered as being coincident. Steam production of 460,000 lbs/hr is the design steam production rate from "N" steam generators.

8. RFP Section 2.2 states "innovations in proposals will be evaluated to determine if creative ideas of

Offeror are a better value to the Government compared to the minimum criteria." If the proposal includes an alternate system configuration that the Offeror believes is a better value for the Government with equivalent guarantees, will the proposal be evaluated even if there is no offering that addresses the minimum criteria?

Section 00 22 20 Paragraph 2.2 has been clarified in amendment 0010 to include the following: "Innovations will be evaluated as betterments. Offerors are responsible for including sufficient details to permit a complete and accurate evaluation of each proposal. Proposals received will be considered proprietary information and shall be clearly marked as such by the offeror. All proposal must meet the minimum criteria.

9. Section 5.2.1.1 (a) Guaranteed Gross Electrical Output references Specification Section 01 91 00.00 40

Performance Testing, Inspection and Commissioning. We do not see this specification section anywhere in the RFP documents. Please provide a copy which we assume will provide the conditions that Performance Tests will be either run at or corrected to. If this information is not included in the referenced specification section, please provide the necessary data.

Delete references to Section 01 91 00 00 40. Commissioning requirements are identified in Section 01 91 00.80.

10. Subparagraph 6.2.1.2 at page 23 of 35, reads in pertinent part: Offerors are required to submit verifiable information on more than three projects that demonstrate the degree . . . to which the contractor utilized small business firms . . . . (emphasis added).

a.Please confirm (i) that "more than three" is correct and (ii) that "no more than three" is not what is meant.

b. If "more than three" is the correct interpretation, is there a limit on the number of projects that can be submitted.

The statement should read "not more than three.

11. In section 3.11.3.8, it states:

"Each HRSG shall...capacity to produce 115,000 lbs/hr of 275 psig steam at a temperature of 550 deg F (header pressure and temperature measured downstream of the boiler envelope piping.)"

Please define the interface for "downstream of the boiler envelope piping."

The boiler envelope piping is equal to Boiler External Piping as defined by Secion 1 of the ASME Boiler and pressure Vessel Code.

12. Section 3.11.3.18 states:

"Condensate Return System...The Contractor shall provide a condensate return system to recover condensate from within the CHPP and for the new steam mains delivering steam from the CHPP."

Please define the condensate return conditions (% of export, temperature, pressure) for return condensate back to the CHPP from the balance of the RFAAP, both for condensate return system design and for performance guarantees.

Condensate amounts and conditions for return condensate identified in Section 3.11.3.18 shall be determined by the design of the Contractor.

Condensate from the RFAAP facility is not being returned to the CHPP.

13. Section 3.11.3.22 states: "Steam Pressure Reduction System...The temperature of steam suppled

...shall be controlled ...is 375 deg F."

The backpressure steam turbine exhaust steam, maintained at 40 psig, will depend on the steam turbine isentropic efficiency. Please confirm that a temperature less than 375 deg F is acceptable.

Section 3.11.5.4 established a minimum steam exhaust temperature of 310F which is to provide a minimum amount of acceptable superheat in the exhaust for delivery to RFAAP.

Section 3.11.3.22 established a higher temperature for 40 psig steam so as to reduce consumption of purified attemperator water.

14. Section 3.11.5.3 (ee)states: "The air inlet chilled water coil...to provide an inlet air temperature to the

CTG of no more than 59 deg F when outside air temperature is 92 deg F (dry bulb)."

The 92 deg F dry bulb is nearly identical to the summer conditions as established in Section 3.11.1.

Please advise if the intent is to size the chiller coil and chiller plant to cool the CTG compressor inlet air temperature to 59 deg F at the summer design conditions as presented in Section 3.11.1. Ambient wet bulb has a large impact on chiller performance and will impact chiller system sizing.

Section 3.11.1 provide criteria for designing the CHPP - including coincident dry bulb and wet bulb temperatures. Section 3.11.5.3 (ee) identifies the dry bulb temperature for sizing the inlet air cooling system.

Therefore, Contractor is to utilize the System Performance Design Conditions from 3.11.1.

15. The RFP states: "...to provide 275 psig and 550 deg F at the boundary between the boiler envelope piping and the ASME B31.1 piping."

This statement does not align with Article 3.11.5.4 (h). This requirement suggests that the steam conditions required at the HRSGs are greater than 275 psig and 550 deg F.

The boiler envelope piping is equal to Boiler External Piping as defined by Secion 1 of the ASME Boiler and pressure Vessel Code.

Distance between this point and inlet to BPSTG is considered to be very limited and reduction in steam pressure and temperature in a stable operating plant minimal.

16. The RFP states: "All performance requirements and guarantees (steam output and fuel input) shall be based on a continuous boiler blowdown rate of 15 percent."

A 15% continuous blowdown rate is very high. Performance guarantees are typically based on 0% blowdown, and normal continuous blowdown may be more typically 0.5% to 1.5%. Please confirm whether 15% is the intended basis.

The water available for feedwater utilization is sourced from the river and has a high silica content, which will not be improved by softening. Experience has shown that 15% blowdown is required to maintain acceptable levels of silica in the drums.

17. The RFP states: Each HRSG shall perform satisfactorily when operated as either a base loaded unit or as a peaking unit, responding to changes in steam header pressure.

Please state the maximum and minimum steam header pressures for proper design of the HRSG and package boilers.

The entire steam generating system shall be desgined to provide a stable 275 psig steam header pressure, with variations of no more than +/- 5 psig on increasing or decreasing load changes.

18. What is the proposed occupant load for the building. Provide Support Spaces staffing and Plant staffing count, if available. By Male/Female, if available.

The male/female split is 50/50.

19. What level of occupancy is proposed for the Lounge/Sleep Area by Male/Female.

50/50

20. The aesthetics lists parapets as "unacceptable." Would a parapet be acceptable at the rake end of the roof, to mitigate the alignment of sloped edges of precast panels or to avoid angled cut masonry? This condition would also not require an extended roof overhang as indicated in Volume I, Section 01 10 00

3.5.8 (b), Figure 3-2 at the rake end to cover the top edge of the wall. Allowing parapets at the rake end would not restrict the flow of roof water drainage to the edge. Is the intent of this restriction to eliminate the roof flashing at the interior side of parapets, including rake ends of sloped roofs and eliminate the joint at the parapet roof intersection?

With the size of the roof under consideration, any unsloped parapet design would result in significant parapet height at the low end of the roof considering UFC minimum slopes. A sloped parapet design would nullify some economy arguments for a parapet. The purpose of the criteria is to provide the highest level of roof system integrity at suitable cost - through minimizing flashing and providing for a continuous roof surface to rake edge. This particular point is thoroughly vetted with the client. The client thoroughly articulated that the aesthetics found in referenced Figure 3-2 are to be used as a guide, subject to approval.

21. Is the vehicular access for the power plant intended to be strictly as a "pass through" access, i.e., loading/unloading of equipment and parts, or is it intended to also facilitate operation and servicing of the vehicles?

Vehicular access is for "pass through" access only.

22. Please clarify which water closet is required. Paragraph 5.6.7.1 (b) contains the word SHALL in the description of both the tank type water closet and the flushometer type water closet. This appears to be a contradiction, and clarification is requested.

Provide Floor Mounted Flushometer Water Closets.

23. Paragraph 6.9.7 states that "Chemical treatment shall be provided for the chilled water piping system.", and Paragraph 6.9.9.1 states that "Single-duct terminal heating variable air volume (VAV) systems shall be provided."

Is the intent of these statements to limit the HVAC systems to a chilled water system with a central air handling unit, and VAV boxes with heating? Please clarify.

6.9.7 applies to the inlet air cooling system and the chiller system dedicated serving HVAC system, if applicable. The HVAC System is not limited to chilled water AHU. Another system may be proposed provided it is supported by Life Cycle Cost Analysis, meets the minimum the energy requirements, and all other requirements of the RFP. Variable volume terminal units with heat shall be provided as indicated in 6.9.9.1.

24. RFP Volume 1 Section 3.11.5.4 Back Pressure Steam Turbine Generator paragraph KK page 105 of 711

" ... as a minimum, the generator protective relaying and associated metering shown on the attached one-line diagram shall be provided."

Please provide the one-line diagram.

The first sentence "As a minimum, the generator protective relaying and associated metering shown on the attached one-line diagram (Attachment 15) shall be provided." shall be deleted from paragraph 3.11.5.4 (kk).

25. RFP Volume 1 paragraph 6.7.1.1(j)(5) on page 307 of 711, indicates there is an existing copper pilot wire protection scheme routed on the 69kV poles that ring the site. Wording in the paragraph indicates the copper lines are damaged and repairs will be made by others in 2015. It also states that the site plans to switch to a fiber system. Please confirm that we will be connecting to a fiber system when the new substation is constructed.

Confirmed. Connection will be to the fiber system.

26. RFP Volume 1 paragraph 6.7.1.1(j)(5) on page 307 of 711, indicates there is an existing copper pilot wire protection scheme routed on the 69kV poles that ring the site. Wording in the paragraph indicates the copper lines are damaged and repairs will be made by others in 2015. It also states that the site plans to switch to a fiber system. If we will connect to the existing copper pilot wire system, please provide information on the manufacturer and model numbers of the existing pilot wire equipment.

Repairs to the pilot wire system will not be made in 2015. Accordingly, in lieu of a connection to the pilot wire system, a fiber-optic cable (FOC) connection should be made between the new CHPP and the Powerhouse subtation and an FOC-to-copper (telephone) converter provided at the Powerhouse substation for future connection to a new pilot wire system.

27. RFP Volume 1 Section 6.7.1 (j) SCADA (2) page 306 of 711 mentions a new radio system and compatibility with existing equipment. Please provide information on the radio system requirements located in the existing substation RTU's.

The SCADA systems is the "HSQ Technology, MISER Version 3.1." The design-builder is responsible for performing field investigations of the existing systems in place at the award of the project and is responsible for the design from that point forward.

28. In RFP Volume II Appendix II Single Line Diagram Powerhouse Substation, drawing number 71-03-55 there are a number of circuits from the 2300V bus A thru D and according to the short circuit study these are for the south, east and west towers. Where will these loads be fed from when the new 4160V power plant is put in service and the existing power plant is removed from service?

The existing Power Plant serves loads other than the 69KV primary. This project provides a new plant as described in the RFP. Taking the existing plant off line and removal of the plant will be a separate project and not part of this RFP. The 2300V circuits along with other loads served from the existing plant will be addressed in that project.

29. Please identify maximum and minimum gas pressures available at the utility delivery point/metering station.

Contractor's design shall be based upon a controlled delivery pressure from the supplier of 400 psig.

30. Please further explain or provide process diagram of hot filtered water storage tank referenced on Vol I

Section 3.11.5.1. This section refers to a hot filtered water connection from the compressed air system(external to this project). Please provide additional information regarding the intent of this system and details on the hot filtered water system.

Section 3.11.5.1 refers to fuel oil.

Section 3.11.5.18 refers to the Hot filtered water tank - To clarify the relationship to the compressed air system : - Filtered water is used to cool the air compression system. Rather than waste this water it will be piped (by others) to the interconnection point where this contractor will bring it into the CHP for use as part or all of the water which will be softened for boiler makeup.

31. Is a copy of the initial air permit application, and 3 supplemental filings, available for review?

A copy of the initial air permit application and supplemental filings is not available.

32. If an Offeror's proposal includes technology differing from those included in the existing permit, will the proposing party be responsible for the cost of developing all permitting data including Gaussian Dispersion modeling to support a revised permit application.

The offeror will be responsible for all documentation supporting the revised permit application.

33. There are no stack test requirements listed in the VDEQ permit for the emergency power generator engine emissions, although numerical pound per hour limits are contained in the permit. It is assumed that vendor certification of compliance with US EPA Tier-based limits will suffice? Please confirm.

Confirmed, vendor certification of compliance with US EPA Tier-based limits will suffice.

34. Have any noise modeling and noise impact studies been performed to verify the "Alternate A" statement that nearby residents will not result in any increase in noise levels?

Due to the terrain/topography, foliage and the distance from RFAAP's perimeter to the nearest private residency no issues relative to nearby residents should arise as a result of this project.

35. Was a formal Environmental Justice (EJ) analysis performed to support the statement in the EA that there will be no impacts from the proposed power plant to minority or low income communities?

An Environmental Justice analysis was performed as a component of the Environmental Assessment effort.

36. The VPDES permit expired on June 9, 2015. Has a new permit been issued and, if so, is it available for review?

The VPDES permit has been renewed. A copy will be posted by amendment.

37. Please clarify the new 8-inch high-pressure natural gas pipe material (carbon steel or HDPE)?

Refer to Section 01 10 00 Para 3.11.5.2 for all requirements related to the gas line from point of connection near Visitors Center through to connection at the CTG, HRSG and Boilers. For the preceeding scope of work Paragraph 3.11.5.2 takes precedence over Paragraph 6.2.7.6 For supply of gas downstream of a pressure regulator which provides gas to "plumbing and hvac" loads such as unit heaters, hot water heaters etc MDPE can be used in accordance with Paragraph 6.2.7.6.

38. Will open cut of roadway crossings be allowed during the installation of the 8-inch natural gas line?

Means and methods are the responsibility of the Contractor. Contractor to fully restore to "new" condition -the entire width of payment where any disturbances or removals of road surfacing occur. Where road cuts are employed the contractor shall maintain open a lane for vehicle traffic at all times, and when not actively working on the gas line the road opening shall be plated over to allow full use by vehicles.

39. Please confirm requirement of cathodic protection with use of MDPE pipe for 8-inch natural gas line.

Cathodic protection shall be provided for steel riser pipes coming off of MDPE gas lines.

40. Will the installation of the new 8-inch natural gas line be subject to inspection by Atmos Energy

Corporation in addition to the government inspection?

No, the new natural gas pipeline will not be subject to inspection by Atmos Energy Corporation. Atmos Energy Corporation's responsibilities end at the meter location (just outside of the RFAAP Visitor's Center).

41. Where is the demark point for the contractor's IT interface? Is it existing?

The demark point for the Contractor's IT interface is the Communications Room in the New CHPP. The Contractor is to provide a four-way ductbank for the facilities interconnect between the demark point and Telecommunications Building 263. See Section 01 10 00 Paragraphs 3.9 Communications and Security Systems, 6.7.8 Communications Outside Plant, and 6.8 Facility Electrical and Communications Systems.

42. The contractor is required to provide a T-1 Data line and two phone lines. Will these be tied to an existing demarcation point within the facility different from the demarcation for the contractor's temporary service?

The demarcation point of the T-1 Data line and the two phone lines is Building Number 263, which it located adjacent to the southwest corner of the project site.

43. Can an electronic, scaled copy of the steam connection points drawing that was distributed at the site visit be provided to aid in determining piping connection points as well as pipe quantity estimates?

Electronic drawing of the steam connection points does not exist. Connection points shown on MS101 are for illustration only.

44. Please provide additional road closing protocols to be used for major deliveries to the site.

Major deliveries should be timed to occur after normal business hours to minimize traffic disruptions at RFAAP during the day. At least one lane on Constitution Avenue - each way - must be maintained open at all times. When a lane must be closed advance notice must be provided to allow notification of all RFAAP personnel that lane closures will be forthcoming. Proper signage and flagmen must be utilized to convey closure of a lane/section of roadway to all approaching traffic.

45. During the site visit, mention was made of potential hazardous areas. Please identify the known hazardous areas / conditions that will affect the construction area, tie-in point work, as well as access to parking and laydown areas.

It is the responsibility of the design team to properly classify and construct the areas within the building.

The mere presence of a gas line into a building for use as boiler or turbine fuel does not create an hazardous area classification.

Contractor shall identify to equipment suppliers that the equipment is to be satisfactory for installation in an electrically non-hazardous area.

46. Regarding overhead power lines, please provide pictures of all overhead power lines on the site and crossing roads which access the project site, and identify which overhead power lines will be relocated.

Please provide elevations for all lines not being removed, and confirm that lines being removed will be removed before mobilization.

All overhead power lines on the project site will be relocated prior to Design-Build Contractor mobilization.

47. Please identify which utilities are available for temporary power, water, phone, and data services during construction for construction activities and construction offices.

Refer to Section 00 73 00 for utility usage.

48. Do any below ground foundations -- associated with previous demolition work -- exist in the proposed construction area?

Refer to Section 01 10 00 Paragraph 3.6.6 Foundations / Geotechnical Report, Paragraph 5.2.2.1 Final Geotechnical Report, and Appendix AA Preliminary Geotechnical Report (Provided for Information Only) for information regarding subsurface conditions.

49. Please confirm that equipment deliveries can be stored on the rail spur (mentioned during the site visit).

If so, please identify where the equipment deliveries may be stored on the rail spur (location) and proximity to the construction site.

The rail spur may be used for deliveries but not for storage.

50. What is the purpose of the proposed retaining wall shown on Sheet C102?

The retaining wall shown in the bridging documents facilitates grade change between the edge of concrete pavement and adjacent slope. Contractor is responsible for final design.

51. To shorten the route of steam connections, is it possible for the steam connections to be rerouted to exit from the western site of the new plant, rather than the way currently shown as exiting along the northern side of the new plant?

Steam pipe routing and connection points shown on MS101 are "proof-of-concept" and for illustration only.

Contractors may propose alternative solutions, but must meet the requirements of the overall specification.

52. Can the offset lane barriers just inside the main gate that are used for security purposes of slowing down entering vehicles (for security purposes) be temporarily removed for short durations to accommodate large equipment delivery in order to avoid difficult or impossible very large vehicle "zig-zag" maneuvering? These appear to be Jersey Barriers and concrete blocks. We assume that the interim removal would require continuous security guard presence as a compensatory measure. If temporary removal is permitted, please also advise if the project will permit the contractor to perform the removal and replacement or if this would be performed by the resident site service contractors.

Temporary removal of the barriers will be allowed based on an approved traffic management/security plan submitted by the contractor.

53. Section F. Control of Hazardous Energy (Lockout/Tagout) states:

1. "Establish a program and procedures for attaching appropriate lock-out and tag-out devices."

and RFAAP General Plant Rules section 5.4.1.1 states: Lockout and tagout of machines and equipment shall be performed only by authorized employees who have received training in the recognition of..."

Please clarify whether the Contractor is to establish their own training and Lock Out Tag Out programs that are compliant with the OSHA regs specified, or whether a site specific program must be followed.

The offeror shall develop their own lockout/tagout procedures in compliance with contract specifications.

54. Of the 10 areas shown on the Gas Chromatograph, which gas supply is preferred for the CHPP?

The Gas Quality Postings provided in the appendices to the RFP were provided to show indicative values for the composition of Natural Gas that would be delivered to the Radford Site. The samples represent a point in time along the length of the East Tennessee Natural Gas, LLC pipeline. The point of connection for Radford is determined by its location along the pipeline. - Furthermore the facility shall operate in compliance with all requirements of the RFP over the range of Natural Gas Compositions permitted in Interstate Commerce by the FERC.

55. Para 6.7.6 reads "grounding system...shall have a maximum acceptable resistance of 5 ohms or less between grounding electrodes and ground."

Please provide any existing resistivity values so we can determine the extent of the grounding system required.

Contractors shall base the pricing on the local soil type information provided in the boring reports. Acquiring the exact electrical soil resistivity will be part of the Contractor's design efforts.

56. Paragraph 6.8.2.5 states that "Switchgear (5kV) shall have a minimum of four (4) spare breaker sections.

Please clarify if the above statement means four (4) vertical sections or four (4) separate breaker compartments.

To clarify the statement in Paragraph 6.8.2.5 "minimum of four (4) spare breaker sections" means four (4) vertical breaker sections.

57. Section 01 10 00 paragraph 3.11.3.7 Inlet Air Chilling System, Absorption Chillers, Chilled Water and

Condenser Water Pumps, and Cooling Tower

(a) The Contractor shall select and size an inlet air chilling system for each CTG based on a double-effect absorption chiller fired with 40 psig steam at the discharge temperature of the selected BPSTG but capable of accepting steam at the temperature of the pressure-reducing station.

The government has required two double-effect steam absorption chillers to provide turbine inlet air cooling that operate on 40 psig steam either provided by the back-pressure steam turbine or the plant steam pressure reducing station. We are unable to locate a manufacturer that can meets those specific requirements. Please provide the basis of design.

York, a division of Johnson Controls, offers availability of double effect (2-stage), absorbers with 40 psig steam within the tonnage required; equipment is manufactured in Mexico, and through NAFTA, made available in the US. Countries with which the US has open trade agreements – meaning mexico, Canada, most of western Europe typically fall within the allowed list of places for federal "Buy American" procurement.

58. (page 265) BAE Piping Specification 18102 calls out Stainless Steel, Schedule 10, 304L for all filtered, tempered or treated water lines AG.

(Page 1050 et. seq.) calls out University of New Hampshire Specification 15000 calls out Specification 15061 for city water, service water, makeup water (softened), and general service.

The two specifications appear to be at odds.

Should we use the BAR piping specifications (1800 series) or the University of New Hampshire piping specifications (1500 series)?

Please clarify, and provide the balance of piping specifications for the BAE system, and the complete Specification 15061.

The BAE specification takes precedence, as it is the more stringent specification.

59. The Specification states that "The USACE Norfolk District's Subcontractor shall be responsible for

MPCS configuration and commissioning and shall coordinate with RFAAP plant personnel to determine correct network addresses and hardware naming conventions for the various devices."

Please confirm that the USACE, Norfolk District will be responsible for integrating and commissioning the MPCS, and that the Design-Builder should not include costs associated with integrating and commissioning the MPCS.

The reference to "subcontractor" in Section 01 10 00 paragraph 3.11.5.27(r)(9) should read "Contractor" and will be corrected in a subsequent amendment.

The design-builder is "USACE Norfork District's Contractor. Therefore, the contractor is responsible for the configuration, integration, and commissioning of the MPCS.

60. Paragraph 6.7.6 states "Cathodic protection for underground utilities (i.e., water, sewer, industrial waste, gas, and storm drainage) that have metal piping and/or fittings in contact with the earth and for tanks shall be provided."

Please reaffirm that the Corps is requiring cathodic protection for Ductile Iron pipe, which typically does not require cathodic protection. This seems an unnecessary cost to the Corps/project.

Provide cathodic protection in accordance with Section 01 10 00 paragraph 6.7.7.

61. Please clarify that the Guarantee Statement intends the plant performance as follows: The plant will be operated, in new and clean condition, with such a gross output that 16 MW is achieved even after applying degradation factors of 96% to each combustion turbine and degradation factor of 98% to the back pressure steam turbine.

See Section 010 10 00, Paragraphs 3.11.3.1 and 3.11.3.4.

62. Please confirm that the pressure required at the HRSG high pressure superheater outlet will need to be higher than 275 psig in order to achieve 275 psig at the Back Pressure Steam Turbine inlet.

Contractor shall size back pressure steam turbine to produce required output with recognition of any degradation of steam pressure or temperature from the termination of the Boiler's External Piping to the inlet of the Back Pressure Steam Turbine. Refer to Secion 1 of the ASME Boiler and pressure Vessel Code.

63. "Please confirm the performance guarantee basis for achieving the 16 MW degraded output is based on the following reference basis parameters. If not, please clarify the guarantee point.

* Fuel - 100% natural gas operation

* CTG Status - 2x operating at 100%, baseload operation

* HRSG Status - 2x operating, fired as required to achieve high pressure superheater exit flow of 115 kpph each

* Boiler Status - 2x operating, high pressure superheater exit flow of 115 kpph each

* BP STG Status - 1x operating at load required to achieve 16 MW as determined per Article 3.11.3.4 of the RFP

* Ambient dry-bulb temperature - 92.1 deg F

* Ambient wet-bulb temperature - 73.0 deg F

* Barometric Pressure - 13.74 psia

* Absorption Chiller Status - ON

* CTG Compressor Inlet Temperature - 59.0 deg F

* Generator Power Factor(s) - 0.80 lagging

* Fuel Gas Pressure Available at Site Boundary - Sufficient for CTG without fuel gas compressors

* 275 psig Steam Header Flow - As available after BP STG and deaerator steam usage

* 40 psig Steam to BP STG - As required to achieve BP STG Output described above

* Fuel Gas Properties - GLADE SPRINGS VA Line 3300 per Appendix PP of the RFP

* Fuel Gas Temperature - 77 deg F

* Electrical Frequency - 60 Hertz

* Makeup Water Temperature - 45 F

* Process Condensate Return - 0%

* HRSG and Boiler Blowdown - 15%"

The performance guarantees are as stated in the RFP. Degraded conditions are specifically identified in section 5.11.3.4.

64. Power-Gen Equipment Requirements question:

Please define the interface for "downstream of the boiler envelope piping."

More than a two boiler fed from a common source, and Multiple Installation Common Header. Reference ASME Section 1 fig. PG-58.3.1.

65. Power generation equipment requirements question:

Please define the condensate return conditions (% of export, temperature, pressure) for return condensate back to the CHPP from the balance of the RFAAP, both for condensate return system design and for performance guarantees.

The design basis does not include the return of condensate from any existing portions of the RFAAP. The contractor shall be responsible for the design and installation of a condensate system supporting the work of this project.

66. Power generation system requirements questions:

The backpressure steam turbine exhaust steam, maintained at 40 psig, will depend on the steam turbine isentropic efficiency. Please confirm that a temperature less than 375 deg F is acceptable.

The back pressure steam turbine shall be designed from a minimum exhaust temperature of 310F (3.11.5.4) so as to achieve a reasonable degree of BPSTG efficiency while still providing dry steam for distribution.

The association of 375F with the 40 psig steam is from 3.11.3.22 where it relates to attemperation of HP steam for producing additional LP steam.

67. Power generation system requirements question:

Section 3.11.5.2 states: "Pipeline...The natural gas pipeline shall be designed...a pressure of 400 psig...."

and "Three packaged boilers with a maximum pressure drop of 15 psig from point of origination near the RFAAP Visitors Center to the inlet of the combustion gas turbines." and "Delivery pressure to all other gas cusumers shall be based on the requirements of individual items of equipment...."

Question:

Please advise on the 15 psi pressure drop requirement. The pressure drop available may be difficult to achieve after accounting for all requested natural gas system components, including regulation, coalescing filter, CTG gas flow meters, and associated block valves.

The pipeline loss of 15 psig starts with the delivery pressure of 400 psig after Metering and Regulation at the point of origination near the RFAAP visitors center, and concludes with attachment of the fuel gas pipe to the CTG's. Contractor to select pipe sizing and components to work within the allowable pressure drop.

68. Power factor question:

What power factor shall be used as the basis for Performance Guarantees?

A power factor of 0.8 will be used.

69. CTG question:

The 92 deg F dry bulb is nearly identical to the summer conditions as established in Section 3.11.1.

Please advise if the intent is to size the chiller coil and chiller plant to cool the CTG compressor inlet air temperature to 59 deg F at the summer design conditions as presented in Section 3.11.1. Ambient wet bulb has a large impact on chiller performance and will impact chiller system sizing.

The intent of 3.11.1 is to provide design conditions for the CHPP which may be different than standard HVAC design conditions. With respect to sizing of the Inlet Air Cooling System for the Gas Turbine Generators. The Contractor shall design for 59 deg F inlet air to the CTG when the outside conditions are

92.1 deg F dry bulb with coincident 73 deg F wet bulb.

70. Back pressure steam turbine generator question:

This requirement suggests that the steam conditions required at the HRSGs are greater than 275 psig and 550 deg F. Section 3.11.3.8 however states that each HRSG shall produce steam at a temperature of 550 F. Please clarify intent.

Contractor shall size back pressure steam turbine to produce required output with recognition of any degradation of steam pressure or temperature from the termination of the Boiler's External Piping to the inlet of the Back Pressure Steam Turbine. Refer to section 1 of the ASME Boiler and pressure Vessel Code.

71. HRSG steam generation question:

This statement "...to provide 275 psig and 550 deg F at the boundary between the boiler envelope piping and the ASME B31.1 piping." does not align with Article 3.11.5.4 (h). According to Article

3.11.5.4 (h), the inlet steam pressure to the back- pressure steam turbine shall be 275 psig. Please clarify.

The boiler envelope piping is equal to Boiler External Piping as defined by section 1 of the ASME Boiler and pressure Vessel Code. Distance between this point and inlet to BPSTG is considered to be very limited and reduction in steam pressure and temperature in a stable operating plant minimal. Contractor shall allow for this minimal reduction in steam pressure and/or temperature in selecting the Back Pressure Steam Turbine such that it provides its guaranteed kwh output and its guaranteed steam input.

72. Air quality control question:

The air permit does not define stack height. Stack height will be based on EPA test port location requirements. Clarification is requested.

Stack heights should be proposed by the bidder with consideration given for the heights of nearby structures.

The stack heights should not be lower than those listed in the May 14, 2014 Air Permit Application.

73. Air quality emmissions - vent stack question:

The referenced sections state that stack diameter and height will be based on the Radford CHPP Air Permit Application. The air permit in fact does not define stack height or diameter. We understand that stack height will be based on EPA test port location requirements. Please confirm if this is acceptable.

VDEQ Form 7 in the May 14, 2014 Air Permit Application lists stack height, diameter and other stack data.

74. Thermal performance question:

Please advise if the requirements of API 611 in their entirety needs to be enforced? Many turbine suppliers do not have the required in-house testing capabilities.

The API 611 requirement to factory test the unit capacity using live steam may be waived if the supplier is unable to perform this test. All other requirements of API 611 will be applicable.

75. Thermal performance - equipment specification question:

This statement specifying rooftop mounted air cooled lube oil coolers is inconsistent with 3.11.5.4 (vi), which reads, "Two (2) 100 percent capacity water-cooled lube oil coolers..." Please identify which statement should govern.

Section 3.11.5.4 is correct, the oil cooler should be an air cooled unit. Section 01 10 00, paragraph 3.11.5.4(s)(7)(vi) will be revised to read "...air-cooled lube oil coolers..." in an amendment.

76. Since this is a back pressure steam turbine, with steam path conditions well above atmospheric pressure, a gland steam sealing system is not necessary. A gland steam leakoff system, with leakoff flows going to a gland steam condenser, is proposed instead. Will this alternate equipment proposal be acceptable and deemed compliant with the proposal requirements?

An amendment will be issued to change Section 01 10 00 Paragraph 3.11.5.5 (t) subparagraphs 1, 2, and 3 to: Gland Steam Sealing System: A gland steam condenser package shall be provided to collect and condense steam from the back pressure turbine shaft seals. Collected condensate shall be drained to a safe location.

77. Hazardous area (electrical) classification question:

We find an unavoidable conflict with this requirement for design and installation in a classifed non-hazardous area. The introduction of a natural gas fueled combustion turbine and natural gas fired steam generation equipment to the building will result in areas within the building needing to be classified as hazardous areas. Please clarify the requirement.

It is the responsibility of the design team to properly classify and construct the areas within the building.

The mere presence of a gas line into a building for use as boiler or turbine fuel does not create an hazardous area classification.

Contractor shall identify to equipment suppliers that the equipment is to be satisfactory for installation in an electrically non-hazardous area.

78. Schematic - capacity requirement question:

Capacities and flows presented are different than what is calculated to meet the Performance Guarantee requirements of the RFP. Please confirm that Steam Piping Schematic M610 (sht 13 of 19) is for informational purposes only and not binding.

Steam Piping Schematic M610 (sht 13 of 19), along with all drawings from Appendix DD, is for informational purposes only and is not binding.

79. Equipment requirements question:

There is no mention of HRSG bypass stack or associated diverter damper in the RFP. However, the air permit application presented on May 14, 2014 to the Virginia DEQ depicts this equipment. Please confirm that an HRSG bypass stack and damper are not required.

See Appendix GG - Environmental Information, Air Permit, including Paragraphs 18 and 30 make no provision for HRSG bypass stack and damper for this application.

80. Section 01 91 00.00 40, Performance Testing, Inspection and Commissioning is referenced many times.

This section has not been found in the RFP documents. Please provide this section.

Commissioning requirements are identified in Section 01 91 00.80. An amendemnt will be issued changing reference of Section 01 91 00.80 in Section 00 22 20 of the RFP (Amendment 0003) to reflect Section 01 91

00.80 - Commissioning.

81. Performance requirements question:

The 15% continuous blowdown rate that is specified is very high. Performance guarantees are typically based on 0% blowdown, and normal continuous blowdown may be more typically 0.5% to 1.5%. Please confirm whether 15% is the intended basis."

Section 01 10 00 paragraph 3.11.5.6 (b) will be revised in a forthcoming amendment to read: "The boiler and all of its accessory systems shall be capable of operating with a continuous boiler blow down rate of 15%;

however for the purpose of evaluating requirements for meeting Performance Guarantees a blowdown rate of 3% shall be utilized." Section 01 10 00 paragraph 3.11.5.8 (c) will be revised in a forthcoming amendment to read: "The HRSG and all of its accessory systems shall be capable of operating with a continuous boiler blow down rate of 15%; however for the purpose of evaluating requirements for meeting Performance Guarantees a blowdown rate of 3% shall be utilized."

82. Performance specification question:

Both of the referenced sections mention that the HRSGs shall produce steam at 115,000 lbs./hr. Please confirm that this is a gross value leaving the high pressure superheater and that deaerator heating steam is to be taken, as needed, from this value.

Steam production rates from steam generating equipment is a gross rate at the designated boundary point and is measured prior to consumption of steam at the deaerator.

83. Environmental permit compliance question:

The specified performance requirement is to meet all requirements of the air permit. Throughout the air permit (Virginia DEQ Registration No 20656) there are restrictions such as annual fuel througput and emissions limits calculated as rolling averages including periods of start-up and shutdown. Emissions generated during start-up, shutdown, and off-design, low load operation are often significantly higher than when operating at higher, normal operating loads (with the CTGs operating at MECL or higher, for example). As such, it is not possible to determine whether the project will meet the Air Permit requirements unless RFAAP is able to quantify startup, shutdown, and low-load operations. An alternative would be for RFAAP to agree to allowing demonstration of Air Permit compliance based on steady-state emissions at normal operating load. Please advise if this method of demonstration is acceptable.

The contractor must meet all guarantees before the facility can be turned over to the goverenment (section 3.11.3.10). The permit as written requires to NOx emissions from the boilers and CTG/HRSG's to be compliant with a 30 day rolling average which does include start-up and shut-down.

84. Performance question:

Please state the maximum and minimum steam header pressures for proper design of the HRSG and package boilers.

Steam generating system design shall control steam pressure in the headers to within +/

- 5 psig of the nominal values (40 psig for low pressure and 275 psig for high pressure) at all times. Sizing of steam distribution headers to minimize pressure losses shall be in accordance with good engineering practice.

85. A 15% continuous blowdown rate is very high. Performance guarantees are typically based on 0% blowdown, and normal continuous blowdown may be more typically 0.5% to 1.5%. Please confirm whether 15% is the intended basis."

The water available for feedwater utilization is sourced from the river and has a high silica content, which will not be improved by softening. Experience has shown that 15% blowdown is required to maintain acceptable levels of silica in the drums.

86. Thermal performance guarantee statement clarification question:

What is meant by the statement "The Offeror shall provide a statement containing an unqualified and unconditional guarantee..."? Bidders will not be able to control how the CHPP is operated and at what surrounding conditions. It is assumed that bidders can state the basis of their performance and emissions guarantees as part of their proposal without the risk of being disqualified. Please confirm the intent of this statement and how bidders are to respond without having control of plant operations following comissioning and handover.

The contractor will be operating the plant during the performance guarantee period (section 3.11.3.10). The performance guarantee period is while the equipment is in new and clean condition (section 00 22 20).

87. Performance and output question:

"Please confirm that the ability to achieve 16 MW of Normal Degraded Output is predicated on absorption chillers in service and a dry bulb temperture of 92.1 F and 73 F wet bulb temperature with a corresponding compressor inlet air temperture of 59 F. At conditions which exceed this design basis for chillers (where compressor inlet air temperture is expected to increase above 59 F), or if chillers are not in service, lower gross output is expected and it is understood this is acceptable. Further confirm this is the relevant sizing basis for the Guaranteed Gross Electric Output – Back Pressure Steam Turbine."

The performance guarantees are as stated in the RFP. Degraded conditions are specifically identified in section 5.11.3.4. Refer to ASME PTC codes for conditions under which tests are to be run, and how to prepare documentation for adjusting measured performance when conditions such as ambient temperature are not per the test protocol.

88. Are the pipe routings current shown in concept required,…