W3P83-0519, Forwards Responses to Questions Re Proposed Installation of Insulco/Hemyc Sys as Fire Protective Envelope for Class IE Electrical Cables.Insulco/Hemyc Sys Presentation Data Encl

From kanterella
Jump to navigation Jump to search
Forwards Responses to Questions Re Proposed Installation of Insulco/Hemyc Sys as Fire Protective Envelope for Class IE Electrical Cables.Insulco/Hemyc Sys Presentation Data Encl
ML20079L448
Person / Time
Site: Waterford Entergy icon.png
Issue date: 02/14/1983
From: Maurin L
LOUISIANA POWER & LIGHT CO.
To: Novak T
Office of Nuclear Reactor Regulation
Shared Package
ML20079L452 List:
References
W3P83-0519, W3P83-519, NUDOCS 8302230335
Download: ML20079L448 (11)
v • d • e


Text

LOUISIANA 242 ottAnosoe sinter P O W E R & L i G H T! P o Box 6008

  • (5041 366-2345

$20$ErsYE L V MAURIN Vice President Nuclear Operations W3P83-0519 February 14, 1983 3-A1.01.04 Q-3-P43 Mr. T. M. Novak Assistant Director for Licensing U. S. Nuclear Regulatory Commission Washington, D. C. 20555

SUBJECT:

Louisiana Power & Light Company Waterford SES Unit No. 3 Docket No. 50-382 Installation of Fire Protective Envelope for Class IE Electrical Cables Use of the Insulco/HEMYC System

Dear Mr. Novak:

In accordance with an agreement made during a telecon with Mr. D. Kubeckie on January 11, 1983, we are formally acknowledging our intent of using the Insulco/HEMYC System as our fire protective envelope for Class IE electrical cables.

In addition, we are addressing four items of concern that Mr. Kubeckie made reference to during the telecon.

Attached to this letter you will find the following information:

1. LP&L's response to the NRC's concern with the temperature levels achieved on the unexposed side of the protective envelope.
2. LP&L's response to the reasoning for utilizing 24 Volts DC as a circuit integrity monitoring voltage.
3. LP&L's response concerning installation and QA/QC procedures.
4. LP&L's response to the NRC's concern over not protecting the structural supports associated with the cable trays and conduits being protected.

q V

Q O

F

W3P83-0519 Mr. T. M. Novak Page 2

5. A comparison of the HEMYC System fire test to the Sandia 20 ft. separation test and CMEB 9.5.1.
6. NES/Insulco HEMYC System presentation data.
7. Fire Qualification Test Report - HEMYC Cable Wrap System LP&L believes this information should aid the NRC in their evaluation of the Insulco/HEMYC System for use as a fire protective envelope for Class IE electrical cables.

If you have any questions or comments on this matter, please contact Mr. Roy Prados, our Licensing Engineering Supervisor.

Yours very truly, u

L. V. Mad [d ^

LVM/EJS/sm Attachment cc: E. L. Blake, W. M. Stevenson, Jim Wilson, D. Kubeckie

r bcci (without attachmenta) Ebasco (2), J. M. Brooks, R. J. Milhiser (2),

F. J. Drummond, T. F. Gerrets C. J. Decareaux. T. K. Armington, P. V. Prasankumar, J. R. McGaha, Richard Hymes. L. L. Bass, M. I. Meyer, R. W. Prados, K. R. Iyengar, Central Records, L. V. Maurin, R. P. Barkhurst, G. B. Rogers, Nuclear Records (3),

Licensing Library, MSS Nuclear Activities (w/Att), G. Buxton i

I i

i.

l l

6

l TEMPERATURE In addressing the NRC concern of the temperature of the unexposed side of the fire protective envelope, it should be noted that njl firm criteria exists related to the qualification of the envelope based on internal temperature reached during a fire test. Qualification of the protective envelope system is based primarily on circuit integrity and insulation degradation. A review of criteria set forth by the involved organizations (i.e., NRC, ANI, and ASTM) indicates the i

following:

NRC -

i l

o No criteria has been established pertaining to the protective envelope system othe'r than the envelope should have a'I hr rating (refer to BTP CMEB 9.5-1, Position C.5.b. (2) (c) ).

o A reference to a maximum temperature of 325'F (on the unexposed side) is stated in C.5.a. (1) (b). However, this criteria is in reference to fire barrier penetration seals designed to prevent ignition of near by combustibles and not applicable to tray or conduit protective envelopes. The results of arevjewofNRC-CMEB9.5-1performedbyNuclearEnergyServices(NES) supports this conclusion (refer to "Compari an of HEMYC System Fire Test to Sandia 20 ft Separation Test and CMEB 9.5-1).

ANI -

o The protective envelope shall be exposed to fire test (ASTM E-119) and i

followed by a hose stream test.

o Maximum internal temperature of the protective envelope is not stipulated.

o Pass / fail criterion is defined as the ability of the protected circuits to maintain continuity and prevent a faulted condition.

i 4

ASTM -

o The scope of the documents issued by this organization are basically the fire testing of building materials (i.e., walls, doors, etc.), and does not consider fire protective envelopes.

o Documents, such as E-119, are referred to for the temperature vs time.

o A criterion of 250*F plus ambient temperature has been established for the unaxposed side of the fire barrier, and not considered as applicable to cable protective envelopes (refer to NRC criteria above).

Summarizing the above, no firm criteria has been established for the qualification of ascable protective envelope based on internal envelope temperature; qualification i

is based primarily on circuit integrity and m$intenance of cable insulation.

  • t A review of the NES study, " Comparison of HEMYC System Fire Test to Sandia 20 ft Separation Test and CMEB 9.5-1", indicated the following:
1) The cables had maintained circuit continuity during the fire qualification testsandsubsequenthosestrea$ tests.
2) Faulted conditions did not exist as indicated by insulation resistance tests.

i These tests resulted in minimum valucs of 600 to ao M et for direct wrap conduit cables and 150 to .o M.ru for the tray cables. (15 M.n- is considered to be adequate by industry standards).

3) No physical damage to the cables had occurred which could adversely effect I the functionability of the cable.

I

4) Maximum thermocouple temperatures for all three tests never exceeded 180*C (356*D at the 50-minute mark of the one-hour test and only one recorded as I high as 215*C (419"F) in single-layered tray and 210*C (410*F) for direct-wrap conduit at the 60-minute end point of the test. It should be noted that these

(4 cont.) temperatures are ambient air temperatures within the envelope; actual cable jacket temperatures would be lower than those listed above; additionally, the conductor (which is insulated by the jacket) would be at a substantially b lower temperature.

As indicated by the NES report, the llEMYC tests resulted in no cable damage, no loss of circuit integrity, or degradation of cable insulation resistance below acceptable industry standards. Since circuit and insulation integrity are the only i

applicable criteria, it is concluded that the HEMYC system adequately demonstrated its ability to protect cable during a one hour (ASTM E-119) fire qualification test and 6ubsequent hose stream tests. This conclusion is s pported by Alil's approval of the system for use ab Waterford 3.

i Additional conservatism is provided by the fact that PE/PVC cable (low-temperature thermo-plastics) were utilized in the B&B test, where-as the cable utilized at Waterford (Qualified IEEE-383 cable; qualified to LOCA and MSLB conditions) is of a much more superior construction.

4 I

l

24 Volts DC Monitoring Voltage

' Three tests were conducted for a variety of insulation wrapping and cable mix configurations for both cable trays and conduits exposed to the standard time-temperature curve defined by ASTM E-119. During each test, control cables were energized with 24 volts de, and connected to a light detection system which indicated the occurrence of short circuits. These tests were conducted with 24v de in lieu of full power to the cables for reasons of personnel safety.

The hose stream test required after the fire test to ensure circuit integrity couldbeverydangeroustothepersonnelcondhetingsuchtesting. Since B&B s could not conduct this test with full power, a thir'd party megger test of the' cables was conducted after the fire and hose stream test.

The "megger" tests (at 500v for a minimum of 30 seconds) were performed to establish insulation resistance values of the cabic and, in addition, a visual examination was conducted to evaluate any visible d'amage to the cable jackets.

a

'I i

Furthermore, the criteria used for testing was the ANI standard, which does not I

address a value of voltage to use for ensuring circuit integrity. B&B knows of l no independent testing facility utilizing rated cable voltages during ASTM E-119 fire testing of cable envelope systems.

I

k

- Installation Specifications The B&B Quality Assurance Department shall be responsible for ensuring that the HEMYC cable wrap system installed at Waterford-3 is identical to the system that was installed during the third party fire qualification test. The following B&B Installation and Quality Control procedures shall be utilized on the installed system to ensure compliance to the system as tested.

I INSTALLATION PROCEDURES

, , l 8400.101 - Installation' Procedure for B&B Insulation Cable Trey Prothetion System -

II Straight Sections 8400.102 - Installation of Insulco/HEMYC Cable Tray Protection System - Curved Sections 8400.103 - Installation of Insulco/HEMYC Cable Tray Protection System onto Single or Multiple Conduits 8400.104 - Repair and Installation of the Insulco/HEMYC Cable Tray Protection System Around Interferences and Obstructions 8400.105 - Manufacture of Insulco/HEMYC Cable Tray and Conduit Protection System Components Quality Control Procedures QCP 10001 - Shipping, Handling & Storage for Insulco/HEMYC Protective Wrap Components QCP 10002 - Manufacturing Inspection for Insulco/HEMYC Protective Wrap Components QCP 10003 - Installation Inspection Criteria for Insulco/HEMYC Protective Wrap Components I

l i

l

Protection of Structural Supports It is L, P, and L's position that structural supports, associated with fire protected cable trays ard conduits, not be provided with a fire protection coating. It is readily recognized that all structural steel assemblies utilized in comnercial and utility applications are not provided with fire resistant materials. The need, extent, and type of structural steel fire protection is based primarily on the anticipated combustible loading of the L.rea, type of occupancy, design loading of the structural members, and the structural steel shape, size, and configuration.

In addition, it is an accepted practice that structural steel inherently contains a degree of fire resistance in itself; this resistance is a function of the steel mass, and the exposed heated surface.

Since the draft issuance of Appendix "R" it had been understood by L, P, and L that several ' options for the protection of essential cable were available to the utilities, i.e. : ,

j

'l

1. Separation'of redundant trains by a three hour fire barrier, and the protection of structural steel that comprise the barrier;
2. Protection of one of the reduntant trains by a one hour fire barrier, plus the installation of an automatic sprinkler system and fire detection systems [ with no requirment for the protection of tray or conduit supports ];
3. Separation of essential cable and equipment by clear (non-combustible) space.

With regard to option (2) -~.the discussion of the need for a one hour fire protection for cables, which a'ppears in the ccanments/ resolution section of the draft Appendix "R" indicates that the purpose of the one hour protective barrier is to allow for interim protection of essential cable (i.e., preclude essential cable from being adversily effected by a fire condition which might exist prior to the activation of an automatic sprinkler system) .

L, P, and L accepts this position that a one hour fire protective envelope will assure the integrity of essential cable, and can provide a one hour barried, sprinklers, and fire detection for these areas. We have found

{ no specific requirement by NRC, or any other authority, which requires protection for cable supports - only that the barrier system be tested to E-119 criterion.

The ASIM E-119 time / temperature curve, used primarily for evaluating building material fire resistance, is presently being utilized in the evaluation of fire protective systems for cable tray and conduits. Although the application of the ASTM E-119 temperature curve may be justifiable in the above cases, it is not reasonable to assume that a credible fire condition, throughout the fire area of the RAB, would approach the severity which is represented by (1)

the E-119 temperature / time response for the following reasons:

a. Combustible Ioading - The Fire Hazard Analysis that the RAB is considered to contain negligible in situ combustibles. Considering the appition of transient combustibles the fire load would not approach the combustibles required to fuel an E-119 furnace. For exanple,a typical E-119 furnace would require approximately 2,20 0,000 lbTd of heat input, an equivalent of 17 gallons of gasoline. It is obvious that administrative procedures, and lack of sufficient space _would prohibit the transportation and storage of such quantities of combustibles within the RAB. In addition, there are no areas

' within the RAB containing essential cable which approxinate the furnace compartment size of 5 'x6'x8'. The RAB fire areas are all larger in volume (most very much larger). Therefore, the required combustibles needed to provide a E-119 time / temperature response would also be proportionably larger. This adds additional assurance that the necessary embustible load would never exist in the RAB areas.

1

-s ,

b. Boundary Conditions - The typical E-119 furnace is designed to efficiently utilize the burned fuel by reflecting heat back into the enclosed conpartment furnace space (approximately 6'x8'x5') and h effectively insulate the furnace space from the outside area. Areas

' of the RAB are not compartmentized or insulated, as such, and there-fore heat is allowed to convect and radiate to the surrounding space within the fire area.

c.

Heat Sinks - In the E-119 test the heat sink consists of the test assemble, while within the RAB numerous heat sinks are available 4

f (i.e. concrete floor and ceiling slabs, concrete walls, equipment, supports, etc.) Also, the RAB is provided with ventilation systems which would supply cool air into the affected fire area, thereby dissipating the heat and minimizing local hot spots. In addition, in all areas where essential cable is fire protected, an automatic sprinkler system has been installed. This system would be activated at ambient air temperatures of approximately 170*F, well below a temperature which could adversly impact structura] steel. This sprinkler discharge would effectively cool the ambient air, components within the area, and ultimately extinguish the fire.

The supports utilized at Waterford-3 are seismically designed and }

construction consists of steel members typically 4" to 8" I beams. This .

seismic design provides a load bearing capacity of approximately 900% greater '

than would be required to support the coresponding normal dead weight loading.

In comparison, the supports utilized in the B and B fire test were 2 - 2 1/2" x 21/2" x 4" steel angles, unbraced against lateral novement and loaded in a manner which developed compressive stress ( a worst case since the conpres- I sive strength of steel is less than the tensile strength) . The angles were not provided with fire protective material except where innediately ac'jacent to the tray. During the one hour fire test the B and B supports maintained their structural integrity. Considering the advantages in physical i

properties (i.e. size, shape, section nodulus) and the inherent over design of (2)

. - . - ~y - , , -- . , . . - -

r ..-

, . _ _ , - ., m .m_,___._..__,,_--.._.-,._.2 .

F the Waterford-3 supports. The Waterford-3 supports would not be adversily affected by an ASTM E-119 type temperature exposure.

Assuming that:

1. If the assumption is maintained that supports associated with essential cable trays throughout the fire areas, are impacted by an E-119 temperature excursion - the next logical application is to assume that all exposM .deel located in the area would be adversily impacted. This would include process pipe, HVAC ductwork, non-essential trays and conduits, and all associated supports. This would have an extreme financial impact on utilities while adding 1ittle in the way of effective fire protection applications. E-119 temperature / time excursion exists in an area which approximates the size of a test furnace (i.e. S' x 6' x 8')
2. Essential trays and conduits are protected by a one hour fire protective envelope, and ,

The heat developed in the space is confined, in order to permit

~

3.

a E-119 temperature excursion l; the affected space would inpact no nore than one of the associated structural supports. This is due to the arrangement of support spacing which is typically 8 to 10 feet on center. Assuming the loss of structural integrity of this single support, located within the affected space, the remaining supports located on each side would provide adequate support for the tray assembly.

In sunmary:

1. The application of an ASTM E-119 temperature excursion throughout a fire area of the RAB is a very conservative postulate. The Fire Hazards Analysis, previously performed, has concluded that there is no need to protect structural steel supports due to the effects of in situ and transient combustible loading.
2. Structural steel supports utilized in the B and B fire qualification test were exposed to an E-119 temperature excursion and maintain their integrity.
3. The Waterford-? 2 ports are considerably more substantial than those tested.
4. Defense in depth is provided throughout the RAB (i.e. administrative controls, early warning fire detection, automatic suppression systems, hose stations and extinguishers) .

(3)

Retrieved from "https://kanterella.com/w/index.php?title=W3P83-0519,_Forwards_Responses_to_Questions_Re_Proposed_Installation_of_Insulco/Hemyc_Sys_as_Fire_Protective_Envelope_for_Class_IE_Electrical_Cables.Insulco/Hemyc_Sys_Presentation_Data_Encl&oldid=3587106"