ML20127K784

Forwards Laboratory Test Repts & Responses That Document Results of Fire Endurance Testing Described in Engineering Rept, Evaluation of Thermo-Lag Fire Barrier Sys

ML20127K784
Person / Time
Site:	Comanche Peak
Issue date:	01/19/1993
From:	William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20127K787	List: ML20127K784 ML20127K789 ML20127K812 ML20128G931 ML20128G949 ML20128G955 ML20128G968 ML20128G986 ML20128G994 ML20128G998 ML20128H018 ML20128H031 ML20128H052 ML20128H068 ML20128H077 ML20128H092 ML20128H102 ML20128H112 ML20128H119
References
TXX-93023, NUDOCS 9301260216
Download: ML20127K784 (22)

Text

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62 Log (/ TXX-93023 Fi1e il 10010.

909.5

7UELECTRIC January 19, 1993 WWlam J. Cahllt, Jr.

Group Yke Presiskat U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555

SUBJECT:

COMANCHE PEAK STEAM ELECTRIC STATION (CPSES) - t= llT 2 DOCKET NO. 50-446 THERMO-LAG LABORATORY TEST RESULTS REPORTS AND PESPONSES TO REQUEST FOR ADDITIONAL INFORMATION FOR CPSES UNIT 2 REF: TU Electric letter logged TXX-92626 from Mr. William J. Cahill, Jr. to the USNRC dated December 23, 1992 Gentlemen:

TU Electric is hereby docketing copies of the laboratory test reports which document the results of fire endurance testing described in TU Electric Engineering Report, " Evaluation of Thermo-Lag Fire Barrier Systems,"

ER-ME-067, Revision 2, interim report dated December 23, 1992 which support the Thermo-Lag installations for CPSES Unit 2. The Engineering Report was submitted to the NRC via the referenced letter. The test reports being docketed are listed in Attachment (1) and were hand delivered to Mr. B. E. Holian of the NRC Staff, and are also available for your review at CPSES. The testing documented in these test reports was conducted under the auspices of Omega Point Laboratories at San Antonio, Texas an industry recognized testing laboratory. The testing was conducted with TU Electric's cooperation and was independent of the Thermo-Lag vendor (i.e., Thermal Science Inc.). These test reports confirmed the conc ksions provided in the Engineering Report ER-ME-067, Revision 2 (Reference 1). By tnis letter TU Electric confirms that ER-ME-067, Revision 2, !s ao longer an interim report and additional confirmation is not required nor warranted. As a result of these tests, TU Electric has concluded:

Thermo-Lag, when procured with the procurement controls established by TU Electric, and installed and inspected in accordance with the requirements of TV Electric's engineering specifications and installation procedures, performs its design functions. Hence, it can be stated that Thermo-Lag performs its intended functions when properly configured. Proper configuration means installed per TU Electric's installations specification and procedures. These TU Electric installation specifications and procedures incorporate the 8/

upgrades, demonstrated by the June, August and November / December 1992 testing, as follows: ,3 , g 22000i t)#{4 tI 9301260216 930119 Qodq' f$. $ $50 '

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TXX-93023 Page 2 of 4 o Thermo-Lag installations for conduit 2 inches diameter and smaller have been upgraded by the addition of a 1/4 inch thick overlay, o Tnermo-Lag installations for cable trays have been upgraded by the reinforcement of unsupported bottom butt joints and vertical joints by stitching and/or additional stress skin.

o Thermo-Lag configurations for LBD boxes, junction boxes, etc., have been reinforced with additional stress skin.

The TV Electric procedural controls utilized to fabricate and to demonstrate these upgrades via laboratory testing at Omega Point Laboratory were the same procedures and controls used to install Thermo-Lag in Unit 2.

Regarding Thermo-Lag functionality, TV Electric has concluded that Thermo-Lag is functional and capable of performing its design function immediately after completion of the installation and inspection. A detailed discussion of Thermo-Lag operability is provided in Attachment 3.

Any as-built deviations from the tested fire configurations were evaluated per the requirements of NRC generic letter 86-10. These evaluations have concluded that the tests have established the acceptability of these configurations. The technical discussion which supports this conclusion is provided in Engineering Report ER-ME-QE2, revision 0 dated January 19, 1993.

TU Electric, therefore, has determined that Unit 2 Thermo-Lag Fire Barrier Systems are considered op ible upon completion of installation.-

During their review of ER-ME-067, the NRC staff posed some specific questions, and requested additional clarifications /information. The requested information follows:

1. Attachment 2 provides responses to the questions posed by the NRC Staff during their reviews.

2. Attachment 3 provides a discussion concerning when Thermo-Lag may be declared operable (i.e., capable of performing its design function).

3. The following clarifications of the Engineering Report, ER-ME-067, ,

Revision 2 were requested by the NRC staff,

a. Conclusions, Section 9.0, page 35 of 94, states that Thermo-Lag performs its design function when properly configured. Various upgrade techniques are described in items 2 through 5 of Section 9.0. These upgrade techniques have been utilized to construct Unit 2 of CPSES through installation specification, CPES M-2032 (Reference 10.14.2), Thermo-Lag Typical Details, CPSES Unit 2 Drawing No. M2-1701 (Reference 10.15.4), installation procedure, CQP-CV-107, " Application of Fire Barrier and Fireprcofing I

h - - _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ___ _ _ _ _ _ _ _

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TXX-93023

-Page 3 of 4 .

l Materials" (Reference'10.18.2), and Quality Control Procedure HQA_ l 3.09-1.07, " Inspection of Fire Protection to Cable Raceway _and Structural Steel".

b. 0 pen Item Number 1, Section 8.0, Page-34 of 94, is " Evaluation _of Unit 1". This will be included in a future revision of the Engineering Report. .

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c. Open Item Number 2,-Section 8.0, Page 34 of 94 'is " Combustibility-of Thermo-Lag". A detailed discussion of Thermo-Lag combustibility is.provided in attachment 4. .Further clarification-will be provided on this item as_ generic. resolutions are ,

developed.

d. Open Item Number 3, Section 8.0, Page 34 of 94, is " Review of

. Finalized Omega Point Laboratories Test Reports". The test reports in attachment 1 have been' reviewed and they confirm the conclusion in the Engineering Report.

e. Open Item Number 4, Section 8.0,'Page 34 of 94, is " Finalization of Ampacity Derating Analysis". The_ basis for the ampacity'-

derating analysis and design of Unit 2 is contained in Section- ^

6.0, Ampacity Derating Factors. This_open. item; exists-to address; Ampacity.Derating Tests that are planned for the future. Refer to section 6.7, Page 31 & 32 of the Engineering Report.

f). Engineering Report ER-ME-067 did not reference test scheme 9-3.

l However, this scheme has been-utilized to evaluate:some configuration deviations addressed'in Engineering Report.

ER-ME-082 " Evaluation of Unit 2 Thermo-Lag Configurations" and has been provided to the NRC. -

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-TXX-93023 Page.4 of 4

4. Attachment 5 provides Engineering Report ER-ME-082, Revision 0, dated January 19, 1993, " Evaluation of Unit:2 Thermo-Lag Configurations".

Sincerely, f

William J. Cahill, Jr.

08/tg Attachments: 1. List of Test Reports

2. NRC Questions on ER-ME-067

3. Thermo-Lag Operability

, 4. Combustibility of Thermo-Lag

5. Evaluation of Unit 2 Thermo-Lag Configurations c- Mr. J. L. Milhoan, Region IV ResidentInspectors,CPSES(2)

Mr. T. A. Bergman, NRR Mr. B. E. Holian, NRR l

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Attachment 1 to TXX-93023 Page 1 of 1 LIST OF TEST REP 0 BIS Hg Schtme # Confiouration

1) Scheme 1-2 Fire Endurance Test of a Thermo-Lag 330-1 Fire Protective Envelope: 36" Tray with Tee

2) Scheme 9-1 Fire Endurance Test of a Thermo-Lag 330-1 Fire Protective Envelope: 3/4 in., 3 in, & 5 in.

Conduits with Radial Bends

3) Scheme 9-3 Fire Endurance Test of a Thermo-Lag 330-1 Fire Protective Envelope: 3/4 in., 1-1/2 in. & 2 in.

Conduits

4) Scheme 10-1 Fire Endurance Test of a Thermo-Lag 330-1 Fire Protective Envelope: Two 3 in. Conduits with Junction Boxes

5) Scheme 10-2 Fire Endurance Test of a Thermo-Lag 330-1 Fire Protective Envelope: Two 3 in. Conduits with Junction Boxes

6) Scheme 11-1 Fire Endurance Test of a Thermo-Lag 330-1 Fire Protective Envelope: 24 in. Iray with Air Drops

7) Scher a 12-1 Fire Endurance Test of a Thermo-Lag 330-1 Fire Protective Envelope: 30 in. Tray

8) Scheme 12-2 Fire Endurance Test of a Thermo-lag 330-1 Fire Protective Envelope: 24 in. Tray with Tee

9) Scheme 13-1 Fire Endurance Test of a Thermo-Lag 330-1 Fire Protective Envelope: 12 in. Tray

10) Scheme 14-1 Fire Endurance Test of a Thermo-Lag 330-1 Fire Protective Envelope: .30 in. Tray with Tee

Attachment 2 to TXX-93023 Page'l of 14

' WESTIONS AND RESPONSES PERTAINING TO

'TU ENGINEERING REPORT ER-ME-067 REV. 2 i

Question 1. Identify where cable overfill conditions exist and what is the technical basis for determining the increase in the height of --

the Thermo-Lag panels to preclude cables contacting the strass skin side of the Thermo-Lag material (see Report Section-4.5.4). Please provide engineering evaluation documentation if available on this subject.

Response 1. CPSES Electrical specifications-prohibit installation of cables above the cable tray rai_ls. If a situation exists where cables are above the rails it is considered a deviation from the specification. A design change authorization is issued to accept this deviation. To. issue a CCA, TU Electric provides an engineering justification. These justifications are on a case by case basis. Example DCA's were made available to the NRC Staff.

Question 2. When will multiple raceways and other commodities in common fire barrier enclosures be evaluated for acceptability (See-Report Section 5.2)?

Response 2. Multiple raceways and other comodities in common fire barrier enclosures that deviate from the typical details for Thermo-Lag installations have been evaluated on a case by case basis through the design change program as required. At the date of this letter, the installation af the Thermo-Lag-barrier system is not complete-for Unit 2. Attachment 5 provides an evaluation of these configurations installed or anticipated to be required. If any new evaluations are j necessary the engineering report will be amended accordingly.

Question 3. The Licensee states that variations in configuration in the field that differ from the approved guidelines (for cable l

ampacity derating) are documented in the Design. Change documents. Please provide a copy of the applicable section of-l DCA-87040 Rev. I which disclosed the-engineering basis that the ampacity derating was not impacted by the configuration variation.

Response 3. Variations in configuration in the plant that differ from the approved engineering details for the installation of Thermo-Lag are authorized by Engineering and. controlled through the design change control program. Each of these design changes is reviewed by the Electrical Engineering Group to assess potential impact on ampacity derating due to the configuration of the proposed Thermo-Lag installation. A copy of DCA-87040, Rev. 1, has been provided to the staff.-

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-AttachmentL2 to TXX-93023

. Page 2 of 14 Question 4.- _Please identify.the draft IEEE standard on "Ampacity Derating-

-of Fire Protected Cables" cited in Report Section 6.1. A: copy of this standard has been provided.-  !

Response 4. The draft IEEE standard TV Electric will be utilizing is IEEE P848/011 " Procedure for the Determination of the Ampacity--

Derating of Fire Protective Cables," Draft 11. April 6, 1992.

Question 5.~ Please provide a copy of the analysis of the thermal resistance of Thermo-Lag as determined in an ambient test environment of 40*C versus the normal plant ambient environment of 50*C (See Report ~ Section 6.3).

Response 5. As the temperature of an insulating material increases-the thermal conductivity increases.. Therefore, since the resistivity is-inversely proportional to the conductivity as the thermal conductivity of Thermo-Lag increases its thermal resistance will decrease. .The thermal resistance of Thermo-Lag will be greater at 40*C than at CPSES's plant ambient of 50*C . With a higher thermal resistance, the cable derate factors will be-higher. Therefore, the CPSES utilizatian of cable derate factors derived from tests conducted at.40'C ambient instead of 50*C is conservative.

Question 6. Please make available test report documentation and drawings for the test articles for EELB-review (i.e., Section 10.2 .

Omega Point Laboratories Final Report.XXXXX-XXXXXX Scheme X).

Note that the SPLB reviewer has expressed similar review needs.

Response 6. The Omega Point Test Reports have been provided to the staff, and are listed in Attachment 1 of this letter.:

Question 7. Licensee stated in Report Appendix A 3ection AZ.7 Comments (whereZ=8through'14)that"Cabletemperatureswereenveloped by the.CPSES LOCA temperature qualifications". .W hat is technical basis'for assertion and does that assertion include-the assumption stated in the October 29,.1992, NRC letter that "the LOCA temperatures bound the fire temperature profile by-including cable operating temperatures."

-Response 7. -The low-level signals carried by instrument cable do not cause

. cable operating temperatures to elevate above ambient.

Therefore, an instrument cable-qualified to a temperature

!l profile higher than the temperature profile experienced.in the L Thermo-Lag fire endurance test should be capable of performing its intended function during a fire. A review of the data for

- cable ~ qualification (LOCAandEQ)determinedthattheminimum peak qualification temperature is 340*F for instrument cable.

qualification. These qualifying tests were conducted at the

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< Attachment 2 to'TXX-93023 Page 3 of 14- .;

cable rated voltage and current. The cables were exposed to-qualification temperature (e.g., 340*F) for a duration of-3 hours and the temperature was then ramped'down to ambient-temperature.

The worst fire endurance test temperatures were a peak cable temperature of 336*F and an average cable temperature of 244*F. Therefore CPSES instrumentation cable qualification bound the fire test temperature and duration. Due to the volume of qualification test data, this data is not being transmitted, but is available on site for inspection.

Question 8. Please provide the' references cited below:

10.16.3_ CPSES Units 1_and 2_ Calculation 16345/6-EE(B)'-004 Rev. O, " Cable Ampacity Derating Factors for Conduits Boxed in with Thermo-Lag (TSI Product)"

10.16.4 CPSES Units'1 and 2 Calculation 16345-EE(B)-140-Rev. 1, "Ampacity of Power Cable Wrapped withi Thermo-Lag 330-660. Installed as Free, Air Drop"- ,

Response 8. Copies of the requested calculations were made available to the NRC Staff.

Question 9. Appendix C of the subject report references as'the derating factor method 40% Calculation / Testing ITL Report 82-335-F-1 for cable trays.- Please verify whether reference is an editorial error to be corrected in the final-Engineering Report.  ;

Response 9. The derating-factor of 40% is correct as stated in Appendix C of ER-ME-067. Refer to Section 6.0 of ER-ME-067 for detailed' -

information.

-Question.10. TU Electric refers to test 1:and test 3~several: times (includingi_nthematrix),whichweredoneto_ original criteria. What portion of test 1 and test 3, does.TU Electric -

take credit for that is not covered by Test Configurations:

14.1 and- 13.1 (respectively).

Response 10. ' Tests 1.and 3 were performed in June, 1992. . Test.3 is not used as a-basis for qualification of Thermo-Lag installed in Unit:2. . Fire Endurance' Tests 14-1 and 13-1 were performed on December 1,-1992, and November 12, 1992,_ respectively. The acceptance' criteria for these tests was the letter dated October 29,-1992, entitled "Thermo-Lag Acceptance Methodology-for Comanche Peak Steam Electric Station - Unit 2". Please refer to page 71 of 94 and 73 of 94 in TU Electric Engineering-Report, Evaluation of'Thermo-Lag Fire Barrier Systems, g q_e* - w

Attachment 2 to TXX-93023-.

Page 4 of 14 ER-ME-067 Revision 2,-dated December 23, 1992.

Test 1-2 along with test 12-1 is being utihzed as a bases for qualification testing of a 36" wide cable tray assembly installed in Unit 2. Although differences exists between the acceptance criteria used in test 1-2 (June, 1992) and the NRC staff letter of October 29, 1992. The following conclusions can be made; a) protected supports.for test 1-2 have no.

influence on test results cable and; b) trayside rail temperatures were sufficiently below acceptance values of October 29, 1992 letter: c) no post hose stream (1 1/2" playpipe) fire barrier inspection was performed, but use of fog nozzle for hose stream test on similar tray test resulted in no adverse effect on the fire barrier.

Upgrade techniques for test 1-2 (36 in. cable tray) are ccnsistent with the techniques proved with test 12-1 (30 in.

cable tray). Therefore, use of test results for scheme 1-2 for qualification of Unit 2 Thermo-Lag configurations with 36-in wide cable tray and upgrade techniques tested in 30 in.

(test 12-1) are justified.

Question 11. What does the word independent mean, with respect to Omega Point?

Response 11. Within the TV Electric Engineering Report (ER-ME-067) the word independent in reference to the testing program for Thermo-Lag means that Omega Point Laboratories is an industry recognized independent testing company. The tests were conducted under the laboratories auspices in cooperation with TU Electric but the independent of Thermo-Lag ve, dor.

Question 12. The October 29, 1992 criteria letter states.that all cables are IEEE-383 and are thermoset. Either reconfirm or provide reference.

Response 12. TU El tric reconfirms that bulk cable procurement for CPSES power and instrumentation circuits installation in raceways is Class 1E. These cables are IEEE 383 qualified and have Thermosetting Insulation. The cables utilized in fire endurance test were from plant inventory.

Question 13. In the October 29, 1992 letter, item 4 states.that in determining the insulation levels an assessment of 1 meg ohm on functionality is required. TU Electric's report does not specifically 6ddress this issue. Provide statements that do so or provide the reference.

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Attachment 2 to TXX-93023 Page 5 of 14 Response 13. The statement in item 4 of the October 29,-1992 letter refers to the acceptability of 1 meg ohm insulation resistance for nuclear instrumentation cables. Nuclear instrumentation at CPSES consists of the Nuclear Instrumentation System (NIS) and the neutron flux monitoring (N16) system. Both systems are capable of monitoring the full range of reactor power. CPSES does not utilize NIS for fire safe shutdown capability and has no HIS installations which are Thermo-Lagged. Therefore, an assessment of 1 meg ohm on functionality is not required.

Instead, the neutron flux monitoring system is used to assess reactor power in a fire scenario. Neutron flux signals are carried over mineral-insulated cables which.are qualified to perform their intended function during a LOCA. One of two redundant neutron flux monitoring channels is routed in 3" conduit-and Thermo-Lagged. The worst fire endurance test temperature for this configuration is less than the minimum LOCA test qualification temperature for these mineral-insulated cables. Furthermore, the LOCA test was conducted over a longer period than the fire endurance test.

Based on the above, we have concluded that the neutron flux monitoring cables will retain their insulating properties and perform their intended function during a fire.

Question 14. On page 18, TV Electric states that test 3 passed the hose stream test. Clarify what these words mean. Explain how the test was performed and explain the acceptance criteria used to determine it passed (This applies to the testing prior to the October 29,1992).

Response 14. The 12" tray test, Scheme 3, was tested prior to the acceptance criteria of October 29, 1992, letter. This test was performed using the ANI Acceptance Criteria that circuit integrity be maintained. The hose stream test utilized a 2 1/2" diameter solid stream playpipe at 30 psi and 20 feet away from the test assembly. Scheme 13-1 confirmed the results of this test with the revised October 29, 1992 acceptance criteria.

[ Question 15. Where does the flame spread rating come from? Does it include top coat?

Response 15. The flame spread of 5 for Thermo-Lag listed on page 5 of 94 in the Engineering Report (Reference 1) is based on an ASTM E-84 Test performed by Underwriters Laboratories, reference UL File No. R6076, dated June 16, 1981. This test was for Thermo-Lag 330-1 Subliming Compound without top coat.' Thermo-Lag 330-1 Top Coat was also tested by UL (reference UL File No. R6076B),

dated June 16, 1981, which yielded a flame spread of 5.

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Attachment,2 to TXX-93023-Page 6 of 14 Question 16. -Test Report 11-1 needs to-include.words to address-the-blistering (whyit'isthere-and-whyitis0K)?-

- Response 16. 'The test report addresses this item.

The following questions pertain te the following references previously provided to the NRC staff.-

References:

A. TU response to NRC RAI. TXX-92589 dated 12-15-92. _

B. TU Calculation No. 0218-CC-0429 (Rev. 3).

C. TV Calculation No. 0218-CO-0271 (Rev. 3).

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D. TV Evaluation of Thermo-Lag Fire Barrier Systems, ER-ME-067, Rev. 2-dated 12-23-92.

Question 17. Enclosure B (Ref. A)-indicates the maximum density of Thermo-Lag material as .073 lbs./cu. in.. P. 25 (Ref. D)-indicates that the maximum weights of Thermo-Lag components are used in-the validation. However, the-calculations on p.-9 to p.'20 .

(Ref. B) indicates the use of Thermo-Lag material density of

.0487 lbs.cu. in.. Provide explanations-for this discrepancy.

Response 17. TheweightofThermo-Lagoncabletraysand~ conduits'(raceway) is based upon the maximum weight of the prefabricated Thermo-Lag pieces allowed by specification 2323-MS-38H.- These-pieces constitute the majority of the weight added-to raceway' systems- i by the fire barrier system.: They are weighed upon receipt and rejected if their weight exceedes the weights al_ lowed by the-specification.

This method uses maximum actual material weights and.back-calculates densities for analysis purposes only. Enclosure B; '

(Ref. A) indicates the maximum weignt of a Thermo-Lag pane 1{to be 5.25 lb/sq. ft. Assuming a-1/2 inch thick panel, a density.

of 0.073 lbs/ca in. is calculated. Ref.-B also uses the maximum weight of a Thermo-Lag panel.of 5.25 lb/sq. ft.

However, Ref. B assumes a panel-thickness of 3/4 inch and .

obtains a Thermo-Lag material density of.0.0487/lbs/cu in.

R While the above two approaches yield different-. values V j Thermo-Lag material density, the total Thermo-Lag we % i calculated:for both cases will be identical. In fact, the 3/4 inch-thick. panel will provide a slightly longer segment than the 1/2 inch thick panel and will result in a slightly higher total weight for the Thermo-Lag.

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i Attachment 2.to TXX-93023"

'Page 7 of.14 The attached Figure 1 and Table 1 and 2 provide an example of the methodology used for the determination of-the weight of--

raceway which.has been covered with Thermo-Lag fire barrier material. The example has individually addressed-all of the components which contiibute to the overall tray weight. .As .

shown in the example the major contributors to the weight used in the raceway analysis and qualification are the cable tray-hardware, the cables, and the initial Thermo-Lag weight. It should bo noted again that the initial Thermo-Lag weight is based on the maximum weight of the prefabritated panels allowedbythespecification(2323-MS-38H)andverifiedon. ._

receipt. The Thermo-Lag upgrade which consists of the stress skin and trowel grade is much smaller contributor to the total C weight. As a result the total weight of the raceway covered with Thermo-Lag fire barrier material is not particularly ,

sensitive to the weight components of the Thermo-Lag upgrade.

For example a 20% difference in the weight o. :he trowel grade ,

material would result in a 1.5% difference in the total l analysis weight. As also shown in the example, this change ,

would be more than offset by conservatism in other weight-components. This is particularly true since the bounding weights are used for the prefabricated panels used in the initial Thermo-Lag application. Receipt inspections show that these panels rarely approach these maximum weights, f

Question 18. A Review of Ref. C indicates that the design validation has been performed for the supports of conduit runs. Provide justification for not assessing the adequacy of conduits, cable-trays and cable-tray supports for additional weight consideration.

Response 18. The purpose of reference C as stated on page 6 is "to design l validate six Train A and B conduits and their associated  !

supports to Seismic Category I Criteria." Each conduit that i is within the scope of this calculation is addressed in a separate appendix. : The supports and. conduit stresses are addressed in each appendix. This calculation is the design validation basis for.only these six conduits. Other conduits and cable tray systems requiring fire protection are cet within the scope of this calculation and are evaluated in other calculations. For conduit attachments to cable trays, footprint loads were sent to the cable tray group and the y attachment approval is included with the' calculation.

i Question 19. P. 3 of Ref. B indicates a variation in the conduit material density with the conduit size. Provide explanation for-this variation.

Response 19. The conduit density as noted on Page 9 of Reference B is obtained from Procedure 21M-5.02-CO Ra ision 2 (PCN-01) Page

. Attachment 2 to TXX-93023 Page-8 of 14

45. The density is the. input required by.the analysis to-determine each element mass. The conduit densities shown include the cable weight and that is why a different density is used for different diameter conduits.

Question 20. Provide a summary of the procedure used in arriving at seismic-loads (in three directions) on conduits, cable-tray and their supports; accounting for the total weigat of the vibratory-systems.

Response 20. Condvit systems are design validated per Procedure 21M-5.02-CND. Conduits are modeled using the computer program P-Delta STRUDL. The mass of the conduit, cables and Thermo-Lag material is accounted for by calculating an equivalent density (Reference B Page 9). The mass and_ dynamic properties-of the STRUDL model, in combination with the input response-spectra are used by the program to determine the seismic loadings.

-Question 21. P. 10-(of 13) of Ref. C indicates-that six trains of-conduit are evaluated under the validation program. Most of them are located in the Safeguards Building. Provide explanation for not evaluating the conduit trains in other structures.

Response 21. As a result of the Fire Safe Shutdown Analysis (FSSA) for Unit 2, several areas have been identified in drawing M2-1700 (Thermo-Lag and RES schedule) as requiring fite protection.

All conduit systems requiring fire protection material have been design validated. ;To expedite the release of conduit systems to construction for Thermo-Lag installation, several_

calculations were generated to design validate the conduit systems. Reference C is the design validation basis for only

• three conduits requiring Thermo-Lag. The remaining conduits are validated in other calculations.

Question 22. P.10(of.39),AppendixA,Ref.C. The table indicates that a number of supports do not meet the acceptance criteria.

Provide details of the process used to qualify them (i.e.,

finc tune the analysis, change acceptance criteria).

Response 22. Unit 2 conduit systems are designed in accordance with the S2-0910 series of generic drawings. These drawings include a set of standard supports that have support capacities listed for them. These capacities are very conservative and assume worst case conditions. However, when the actual conduit' load exceeds these generic support. capacities a more detailed analysis is performed as allowed in procedure 21M-5.02-CND Revision 2. -In Appendix A of Reference C, the support frames-are each modeled individually using STRUDL. The conduit loads

1 a:

Attachment 2 to TXX-93023-Page 9 of_14 and actual 'g' values are_taken from the conduit'RSM analysis.=

m The computer run made for the support has a code check feature that checks the. stresses of-the support members. The frequency __of_the support is then_obtained from tre support run to ensure that the assumed support frequency used-in the conduit RSM analysis is acceptable. The remaining items of-thesupport(welds, baseplate,anchorbolts, punching-shear,,

etc.) are then checked-individually as= required.

When possible, conservative hand calculations are used to-determine support reactions, support-frequency and support. ._

member stresses. Thus, although the conduit load may exceed the generic support allowable as shown in the S2-0910, drawings, a more detailed analysis shows that the supporting.

structures are adequate.

Question 23. Provide a summary of hardware changes (modifications, additions) implemented (or planned) as a result of the validation program.

Response 23. In general there were three types of hardware modification I which were required: ,

TYPE 1 In some cases, supports were added to the conduit system to alleviate over stress of conduit. This usually occurred _on-overhang spans that exceeded 1 foot in length. It is estimated that this type of modification was. required to 6 to '

8 conduits;-

TYPE 2 i

The second major type of modification was-the addition of a-bracing member to.an existing conduit support to relieve support overload. It is estimated that this type of-modification was-required for 12 to 14 conduit supports; and.

TYPE 3 The other modification used was to cut the overhar.g span and-increase the flexible conduit to the maximum allowed length.

This resulted in a shorter overhang span and reduced the-conduit stresses to acceptable levels,~ It is estimated that this type of modification was used in only 1 instance.

1 Listed below are some specific examples ~of modifications required due to the addition of Thermo-Lag and the Unit 2

, Thermo-Lag upgrade:

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Attachment 2 to TXX-93023 Page 10 of 14-Conduit Calculation Ddcription 4

3/4" C24040032 0218-CO-0437 Two supports were added to reduce 1 overhang length to eliminate over stress of the conduit. ,

i 1" C23040029 0218-CO-0437 One support was.added to. reduce the overhang length to eliminate over stress of the conduit,

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1" C22005857 0218-CO-0437 One support was added to reduce.the overhang length to eliminate over stress of the conduit.

1" C22006500 0216-CO-04'21 One support is added to reduce the 4 span length to eliminate over stress of the conduit.

1" C23G40037 0218-CO-0437 A brace is added to support

'C23G08953-05 to alleviate support overload.

1" C22005804 0218-C0-0368 A brace is added to support -05 and

-12 to alleviate' support overload.

Question 24: What seismic damping levels have been used for the design of  !

CPSES Unit 2 conduits which require the installation of 4 Thermo-Lag fire barrier material?

Response 24: All Unit 2 Safety Related conduits have been validated using 2% OBE and 3% SSE seismic floor response spectra. This includes all conduits which require Thermo-Lag and the Unit 2 Thermo-Lag upgrade.

Question 25: What are the peak seismic spectral accelerations used for the va'lidation of conduits and cable trays which require the installation of Thermo-Lag fire barrier material?

Response 25: The highest peak spectral accelerations for each building containing-conduits and cable trays requiring Thermo-Lag is provided in' Table 3. These are the maximum accelerations for these buildings. "he i cable trays and conduits which require Thermo-Lag are designed based on the spectral accelerations at the building elevations at which they are located. These accelerations may be somewhat lower-than those provided in Table 3.

5httachment2tolTXX-93023 e' Page.11 of 14'

. CONSIDERATION OF THERMOLAG WEIGHT :

IN THE CABLE TRAYS DESIGN VALIDATION-

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A DETERMINATION OF TIIERMOLAG WEIGIIT FOR RACEWAY QUALIFICATION ? -d

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Specification'. '3.0 5.25 5.25'..

' INITIAL 1/2'. inch nominal '

Ib/sq.ft- Ib/sq.ft lb/sq.ft TilERMOLAG thickness Thermolag panels Stress. skin' upgrade - Scaled from 1.0 1.92 1.92 THERMOLAG Ib/sq.ft lb/sq.ft lb/sq.ft1 UPGRADE used. equivalent.1/4 inch Specification thick Thermolag panel e

TABLE- 1'

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.L-COMPONENT D2SCRIPTION ANALYSIS .% ACTUAL  %. l"'

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. -4 A CABLE TRAY HARDWARE' -20 28.57 20- 30.97l  %

5- B- CABLES 17.77- 25.39' 12.34 **- 19.11' C - INITIAL THERMOLAG 26 37.14 26 '40.27-' 9!

S.28 '7.54 *- ***-

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'e WEIGHT C+D+E TOTAL WEIGHT OF 32.23 32.23 THERMOLAG TOTAL 70 100 64.57- 100 (A+B+C+D+E)

• . Total thermolag upgrade weight for 24h ' cable tray: 1 3.25 ft (Perimeter)'X 1.92 lbs/sy.ft:=:6.23 lbs/ft ,

• • Basedeon total actual cable weight lfor.RacewayLNo. T-23G04918 (T23GCCD67 -'T23GCCC68)

• • • Weight of thermolag upgrade as'a percentage of'. total actual. weight:

TABLE. 21.

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' Attachment 2 to TXX-93023 Page 14 of 14 BUILDING SAFEGUARD ELEV. 896.5 ELECTRICAL ELEV. 873.33 AUX 1UARY ELEV. 899.5 FUEL HANDolNG ELEY. 918.0

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HORIZ VERTICAL HORIZ VERTICAL HORIZ VERTICAL HORIZ VERTICAL PEAK"G" , OBE 2% 3.29 2.18 2.54 1.93 3.78 2.72 3.66 1.47 PEAK"G" OBE4% 2.28 ~ 1.5 ' 1.79 1.32 2.66 1.71 2.30 0.98:

PEAK "G" SSE 3% 4.25 2.85 3.09 2.90 4.57 3.69 4.52 2.13 PEAK *G* SSE 7% 2.45 2.01 1.85 1.77 2.72 2 11 2.70 1.29 F

TABLE 3 I

Attachment 3 to TXX-93023 Page 1 of:2.

BERM 0-LAG OPERABILITY During the independent fire endurance qualification testing which TU Electric performed at Omega Point Laboratories in San Antonio, Texas, test assemb_ lies were cured for 30 days prior to testing. The 30 day cure period-was included into the test program after discussions with the NRC Staff.

During these discussions NRC staff was concerned that the additional moisture in the Thermo-Lag before the 30 day curing period would give non-conservative resuits. To address this concern TU Electric took this measure to assure that the tested assembly had cured (dried out) prior to the fire-test which assured that moisture present in the material prior to drying out would not aid in the performance of the material during a fire endurance-test. Having material installed in the plant that has not received a 30 day-cure or drying out period would only enhance the performance of the material in the event of a fire during the first 30 days after installation of the

-Thermo-Lag.

Notwithstanding the above, TV Electric procures prefabricated panels _ and shapes of Thermo-Lag. The Thermo-Lag vendor applies top coat to the prefabricated panels and shapes. Additionally, conversations with the vendor confirms that there is no requirement for 30 day cure time, and that upon receipt by the customer the prefabricated material is capable of performing its design function. There are also no vendor guidelines which-require that the trowel grade Thermo-Lag 330-1 material to be cured for 30 days. TU Electric applies top coat only at joints, seams and trowel graded material. TU Electric specificatior.s require that top-coat should be applied over Thermo-Lag material after allowing a minimum of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> cure time, or obtaining a reading less than 100 using a Delmhorst Model DP moisture meter with a scale of 0-100. The cure times stated in the specification (CPES M-2032) are to allow the material (trowel grade 330-1) to dry before. applying Top Coat to ensure that the Top Coat adheres properly.

Top coat is a paint used to provide an environmental (e.g., water,, dirt) protective finish for the Thermo-Lag. The top coat is not required for fire

-barrier operability. This is based on past testing which was done at U. L.

testing laboratories and Gulf State Utilities fire testing program where top coat on Thermo-Lag was not applied.

Based on the above discussion TV Electric concludes that Thermo-Lag is functional, capable of performing its design function,-immediately after completion of the installation and inspection. A Thermo-Lag installation-consists of prefabricated-board or conduit sections that are supplied by the manufacturer in a ready for service condition, trowel grade material that is used to pre-butter joints, stainless steel wire and banding material, staples, and stress skin. The tie wires, staples, and stress skin provide a

-Attachment 3-to TXX-93023-Page 2 of 2- _

- mechanic.a1 reinforcement-of--the-Joints. After these materials are assembled and inspected the installation is operable.- The top coat is-not required ' '

for the Thermo-Lag to be operable and is applied to prevent degradation from environmental effects of moisture and dirt over the life of the plant.

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1 Attachment 4 to TXX-93023 Page 1 of 1 CQtEl$TIBILITY Of THEPJiO-LAG Information Motice 92-82, "Results of Thermo-Lag 330-1 Combustsbility Testing", oated 12/15/92, was issued to convey the results of Thermo-Lag 330-1 combustibility tests conducted by the National Institute of Standards andTechnology(NIST). TU Electric believes that this notice alerts addressees of two potential uses of Thermo-Lag 330-1 for which comtustibility may pose a concern.

Issue 1. Some Licensees use Thermo-Lag fire barrier material to enclose intervening combustibles to achieve 6.1 meters (20 feet) of separation free of intervening combustibles between redundant safe shutdown trains.

Response 1. At CPSES, Unit 2 Thermo-Lag is not used to enclose intervening combustibles to achieve 20 feet separation free of intervening combustibles, between fire safe shutdown trains.

Issue 2. Some Licensees use Thermo-Lag to construct radiant energy heat shields inside containment.

Response 2. At CPSES, Unit 2 Thermo-Lag is not used as a radiant energy shield inside containment.

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