ML20085C591
| ML20085C591 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 05/31/1995 |
| From: | Querio R COMMONWEALTH EDISON CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML19330G028 | List: |
| References | |
| NUDOCS 9506150413 | |
| Download: ML20085C591 (8) | |
Text
.
(ommonwealth Edium (nmpan) lealle bencrating StJtton 2601 North 21st Ru.id
\\larwsHrs. 11 61.4414'%
1cl m s 4s.r, <,i May 31, 1995 United States Nuclear Regulatory Commission Washington, D. C. 20555 Attention:
Document Control Desk
Subject:
LaSalle County Station Units 1 and 2 Response to the NRC Request for Additional Information Regarding Use of Darmatt 2-1 in a Seismic Event NRC Docket Numbers 50-373 and 50-374
Reference:
1)
NRC Letter dated January 10, 1995, from W. D.
Reckley to D. L. Farrar Reference (1) provided the NRC Request For Additional Information regarding the expected behavior of the Darmatt E-1
)
Fire Barrier System and related plant structures during seismic events.
In response to the NRC's request, LaSalle Co. Station provides the following response:
Question No. 1 requested the following:
" Provide sketches for cable trays and conduits showing thickness, number of layers of barrier (s), and attachment hardware for all straight and curved configurations of the raceways."
Response
The installation of the Darmatt 2-1 material has been completed, in both LaSalle Co. Units 1 & 2.
The drawings used for installation of this material are listed and provided in Attachment A.
The drawings apply to the installation of the Darmatt 2-1 on cable tray, conduit and supporting hangers.
From these drawings, the thickness and number of layers of the fire barrier, and the attachment hardware for straight and curved configurations can be seen.
Please note that the information provided in Attachment A is considered proprietary by Comed.
Therefore, the NRC staff is requested to control this information as proprietary, accordingly.
9506150413 950531
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j Document Control Desk (2)
May 31, 1995 Questions No. 2 requested the following:
" Provide weight and mechanical properties (e.g.,
tensile i
strength, congpressive strength, shear strength, flexural strength, modulus of elasticity) of the proposed barriers that are useful in determining the seismic resistance and mode of failure under postulated seismic events at the plant."
i
Response
\\
Fer the purposes of evaluating the performance of the Darmatt 2-1 material for its as-installed applications at l
LaSalle Co., no credit has been taken with respect to the capability of the material to remain intact during a postulated seismic event.
Accordingly, the requested information that is relevant to this evaluation is the specified weight of the Darmatt 2-1 material for LaSalle Co. of 26 lb/ft, as installed on a 30 x 6 inch cable tray.
This weight value is used in the Seismic Category II/I i
evaluation described in the response to Question No. 3, below.
t The properties of tensile strength, congpressive strength, shear strength, flexural strength and modulus of elasticity, can be determined for the Darmatt 2-1 material.
- However, these parameters have relevance only if the Darmatt would be providing any structural support function or if the material is required to maintain structural integrity.
Since this is not the case at LaSalle Co., these parameters do not apply.
1
~ Question Ih. 3 requested the following:
" Provide information related to the seismic resistance of the.
j proposed fire barrier panels established through analyses or testing, and demonstrate that under postulated seismic events, the failure of the proposed fire barrier will.not jeopardize the functioning of the safety-related structures, systems, and components located in the vicinity of the raceways, and of the i
congponents to which the proposed fire barrier is to be installed."
Response
For LaSalle Co. a Seismic Category II/I evaluation was performed to ensure that the potential failure of the Darmatt 2-1 material during a seismic event will not affect any safety related cornponents.
This evaluation conservatively assumes a failure of the installed Darmatt
Document Control Desk (3)
March 31, 1995 I
KM-1 material during the postulated seismic event and concludes that such a failure will not affect any safety related cornponents.
Based on a walkdown and drawing review for both Units 1 and 2, the maximum drop height of the Darmatt 2-1 material has been determined to be no more than 62 inches for the cable tray, 48 inches for the bus duct, 50 inches for the electrical conduit and 57 inches for the HVAC duct located below the Darmatt KM-1 insta!.lations.
This maximum height was used to prepare inqpact calculations for each case.
Utilizing the 26 lb./ft. value, the weight of a representative Darmatt KM-1 piece falling is 12 lbs.
Calculating the ductility ratio for each case has determined a worse case ductility ratio value of 5.3 for the HVAC duct, which is significantly less than the value of 10 allowed in Appendix A of SRP Section 3.5.3, " Permissible Ductility Ratio For Overall Damage Protection".
The results indicated that these conqponents will be able to withstand the impact of dropped Darmatt KM-1 pieces during a seismic event.
Also, there are no inqpact sensitive cornponents such as gages, dials and relays located beneath the Darmatt installations that could be significantly affected.
Therefore, overall, the failure of the installed Darmatt KM-1 fire-barrier will not jeopardize any safety related structures, systems and cornponents from performing their intended safety function.
Questions no. 4 requested the following:
"Considering the appropriate weights of the fire barriers and installed accessories (e.g.,
fasteners, bands, wire mesh),
provide information related to the ability of the raceway supports and anchorages to withstand the postulated seismic events without exceeding the established acceptance criteria."
Kasponse:
The raceway supports and anchorages were evaluated for the applicable design basis loads using the distributed weight of 26 lbs./ft, for the Darmatt KM-1 material and its required mounting congponents, plus a conservative 5% for any residual material from the removed fire proofing system (Kaowool and Thermo-Lag 330-1).
The evaluation applied the weight of the One-hour Darmatt KM-1 fire barrier enveloping each power cable tray and each control cable tray for the following Unit 1 and Unit 2 cable tray routing points:
Document Control Desk (4)
March 31, 1995 Unit Cable Trav Tvoe Routina Points i
1 Power 163A 164A 165A Control 163B 164B 165B 2
Power 153A 154A 155A Control 153B 154B 155B The results of the evaluation have determined that the affected supports and anchorages are acceptable as-installed for the new, required' design load changes.
9 Document Control Desk (5)
March 31, 1995 To the best of my knowledge and belief, the statements contained in this document are true and correct.
In some respects, these statements are not based on my personal knowledge, but on information furnished by other Comed employees, contractor esqployees, and/or consultants.
Such information has been reviewed in accordance with company practice, and I believe it to be reliable.
If there are any questions or cosunents concerning this letter, please refer them to me at (815) 357-6761, extension 3600.
Respectfully, 8%
R. E. Querio Site Vice President LaSalle Co. Station Attachments:
(A)
DARMATT Installation Drawings, LaSalle County Station:
These Drawings are considered PROPRIETARY (B)
Robert M. Goss, President Transco, Affidavit for Attachment (A) l J. B. Martin, Regional Administrator, Region III cc:
W. D. Reckley, Project Manager, NRR P. G. Brochman, Senior Resident Inspector, LaSalle l
ATTACHMENT B Robert M. Goss, President Transco, Affidavit for Attactment (A)
4 TRANSCO PRODUCTS INC.
AFFIDAVIT I, Robert M. Goss, being duly sworn, depose and state as follows:
(1)
I am President of Transco Products Inc. (Transco) and have reviewed the confidential commercial information described in Attachment A which is sought to be withheld, and am applying for its withholding.
(2)
The information sought to be withheld was developed for Comed, pertaining directly to the resolution of the Thermo-Lag issue at LaSalle Co. Station. Transco is the owner of the confidential commercial information. Specifically this information is the Darchem drawmgs listed and included in Attachment A.
(3)
In making this application for withholding of. such confidential commercial information, Transco relies upon the exemption from disclosure set forth in the Freedom ofInformation Act (FOIA),5 USC S 552 (b) (4), and NRC Regulations 10 CFR GS 9.17(a) (4), and 2.790 (a) (4) for " commercial or financial information obtained from a person and privileged or confidential" (Exemption 4).
The confidential commercial information should be withheld from disclosure und CFR S 2.790 (b) (4) for the following reasons:
(a)
The information marked Proprietary or Confidential and is of a sort customarily held in confidence by Transco. Access to such documents within Transco is limited on a "Need to know" basis.
Disclosures outside Transco are limited to regulatory bodies, Test Program Utility Participants (under restrictions that preclude further disclosure), their agents or licensees, and others with a legitimate need for the information, and then only in accordance with appropriate regulatory provisions or proprietary agreements, as authorized under contract by Comed; (b)
The information has, to be the best of my knowledge, consistently been held in confidence by Transco and Comed, and has not been publicly disclosed. All disclosures to third parties including any required transmittals to NRC, have been made, or must be made, pursuant to regulatory provisions or under restrictions as described above.
Page1 e
(c)
The information sought to be withheld is being submitted to the NRC in confidence; and (d)
The information is not available in public sources.
State ofIllinois
)
)
SS:
County of Cook
)
Robert M. Goss, being duly sworn, deposes and says:
That he has read the foregoing amdavit and the matters stated therein are true and 6
correct to the best of his knowledge, information and belief.
Executed at Chicago, Illinois, this 19th day of May.1995.
(
0 bert u. coss
~
President Subscribed and sworn before me this' day of-95.
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State ofIllinois t
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