Information Notice 1995-49, Seismic Adequacy of Thermo-Lag Panels

Seismic Adequacy of Thermo-Lag Panels

ML031210507
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	10/27/1995
From:	Crutchfield D Office of Nuclear Reactor Regulation
To:
References
IN-95-049, NUDOCS 9510240388
Download: ML031210507 (10)

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555-0001 October 27, 1995 NRC INFORMATION NOTICE 95-49: SEISMIC ADEQUACY or THERMO-LAG PANELS

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this informationuse of

notice to inform addressees about two specific concerns related to the

Thermo-Lag 330-1 fire barrier material: (1) actual properties of the

mechanical material could be significantly different than the numerical values

used (or provided) by the vendor to demonstrate the seismic adequacy of

Thermo-Lag 330-1 panels and (2) the actual weights of the installed Thermo-Lag

panels could be appreciably higher than the weights calculated from the

minimum thickness. It is expected that recipients will review the information

for applicability to their facilities and consider actions, as appropriate, to

avoid similar problems. However, suggestions contained in this information

notice are not NRC requirements; therefore, no specific action or written

response is required.

Description of Circumstances

A July 21, 1992, petition filed by the Nuclear Information and Resource

Service (Accession Number 9208280125) raised a "seismic issue" regarding the

Thermo-Lag fire barrier. In response, the staff studied the issue and

concluded that the shattering of raceways or severing of cables required for

safe shutdown are not credible scenarios (letter from T. Murley to

M. Mariotte, February 1, 1993 [Accession Number 9302110146]) under postulated

seismic events at nuclear power plant sites. The staff response was based on

acceptance of the analyses performed by a consultant of Thermal Science, Incorporated (TSI). TSI, which manufactures and supplies Thermo-Lag fire of

barrier material, provided the consultant with the mechanical properties

Thermo-Lag.

On November 11, 1994, the Tennessee Valley Authority (TVA) submitted the

results of simulated seismic tests and mechanical properties tests related to

the use of Thermo-Lag fire barrier material at Watts Bar Nuclear Plant

(Accession Number 9411250234). These tests indicated significantly lower

mechanical properties values compared to those used by the TSI consultant.

During the staff review of the application for an operating license for

in

Comanche Peak Steam Electrical Station, Unit 2, the issue of uncertainties

the weight of Thermo-Lag panels arose.

95102403884Boh FOR EVE poCi- 9s-oY CS/t

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-.-- IN 95-49 October 27, 1995 Discussion

power

The regulations that address the need for fire protection at nuclear Design

plants, that is, 10 CFR Section 50.48; Part 50, Appendix A, General fire barriers

Criterion 3; and Part 50, Appendix R, do not explicitly require after

to be seismically qualified (i.e., to maintdin their integrity Guide 1.29, postulated seismic events). However, provision C.2 of RegulatoryCategory II

"Seismic Design Classification," addresses the issue of seismic considered to

versus seismic Category I. In that context, a fire barrier is are

fire barriers

be seismic Category II. Based on these provisions, the However, the

allowed to undergo damage during the postulated seismic events.

they could reduce

fire barriers should not be damaged to such an extent that structures, the functioning of the protected cables or other safety-related

systems, or components.

Two specific issues are discussed in the following paragraphs:

Seismic Adequacy of Thermo-Lag Fire Barrier

The seismic adequacy of various configurations of Thermo-Lag panels of the

attached to the raceways has been determined by static analyses and

configurations, which were subjected to simultaneous horizontal

vertical accelerations of up to 7.5g and 5.0g, respectively. The

analyses were performed by a TSI consultant using the mechanical

properties (i.e., tensile strength, shear strength, and corresponding

moduli) at various temperatures provided by TSI. The consultant

concluded that the panels and conduit wraps were seismically adequate. that

On the basis of its review of these analyses, the staff concluded undergo

properly installed Thermo-Lag panels and conduit wraps would not

nuclear

appreciable damage during the postulated seismic events at the

reactor sites. Because of the nonductile nature of the material, small

Thermo-lag panels and conduit wraps might crack and crumble into would

motion; however, they

fragments or powder under a strong vibratory

not cause damage to the protected raceways or other safety-related

components or equipment in the vicinity of the raceways.

The November 1994 TVA submittal provided the results of mechanical material

properties tests related to the use of Thermo-Lag fire barrier

at Watts Bar Nuclear Plant. A comparison showed that the TVA-tested

used by

mechanical properties values were considerably lower than those of the

9208260065]. Enclosure 2, the TSI consultant [Accession Number of

TVA submittal shows, for example, that the average tensile strength varies

the 1.59-cm-thick [5/8-in.] Thermo-Lag panel at 53 'C (127 'F)

and

between 2.38 megapascals (Mpa) [345 pounds per square inch (psi)]psi).

3.36 Mpa (488 psi), while the TSI consultant used 4.96 Mpa (720

IN 95-49 October 27, 1995 letters

In December 1994, pursuant to 10 CFR 50.54(f), NRC sent followup to the

to Generic Letter (GL) 92-08, "Thermo-Lag 330-1 Fire Barriers," 330-1 licensees and construction permit holders that had used Thermo-Lag for

fire barrier in their plants. These letters included a request1(9)

additional information and some background information. Item the

requested information related to the mechanical properties of the licensees

Thermo-Lag material. A number of responses indicated that

depended on the analyses performed by the TSI consultant.

results of

Enclosure 1 of the November 1994 letter from TVA contains the

the seismic testing performed by Wyle Laboratories of Huntsville, Alabama, for selected configurations of raceways with the Thermo-Lag mechanical

panels installed. TVA sponsored the seismic tests and the analyses)

properties tests to ensure (through shake-table testing and

performance of

that Thermo-Lag will not adversely affect the safety staff

The

related equipment, for example, cables and cable trays. performed by

review of the test results and of supplementary analyses installed in

TVA indicates that the Thermo-Lag 330-1 fire barrier, when to

accordance with the TVA installation procedure, will be able

TVA Watts Bar plant

withstand the postulated seismic events at the

systems and components.

without adverse effects on the safety-related

Variation in Weight of the Fire Barrier Material

A review of the "as received" weights of Thermo-Lag 330-1 panels, barriers

prefabricated conduit sections, and 330-660 flexi-blanket fire percent in

indicated that there could be a variation of as much as 45 calculated as a percentage of

the unit weights of the fire barriers when The

the weight associated with the thickest panel (maximum weight).

variation is primarily related to the variation in the thickness could

tolerances. For example, the thickness of a 1-hour-rated panel indicating a

vary between 1.27 cm (1/2 in.] and 1.91 cm (3/4 in.], thus

variation could

variation of 33 percent. The remaining 12-percent weight of

result from the variation in the density of the material. The

one layer of stress skin, staples, steel bands, and trowel-grade

average

material (applied during the installation) can increase the method used by

weight of a panel by about 10 percent. Depending on the

of the Thermo-Lag fire barrier in

licensees in incorporating the weight the

seismic analysis of the raceways and their supports and anchorages, maximum unit

effects of the variations could be nonconservative when the staples, weight of the fire barrier and its accessories (wire mesh, the

bands) is higher than the nominal values considered in determining

loads on the raceways and their supports and anchorages.

of the

Summary reports that are submitted to address the seismic adequacy and

electrical and mechanical equipment in accordance with GL 87-02 of Mechanical and

Supplement 1 to GL 87-02, Verification of Seismic Adequacy 19, 1987 and

Electrical Equipment in Operating Reactors," dated February

will consider

May 22, 1992, respectively, will be reviewed by the staff who safety of the

the effects of the fire barriers in assessing the integrated

raceway systems and other equipment.

• _- IN 95-49 October 27, 1995 This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Division of Reactor Proglam Management

Office of Nuclear Reactor Regulation

Technical contact: Hans Ashar, NRR

(301) 415-2851 Attachment:

List of Recently Issued NRC Information Notices

A(1'Jz,- ';S ~

re-Attachment

IN 95-49 October 27, 1995 LIST OF RECENT1Y ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

95-48 Results of Shift Staffing 10/10/95 All holders of OLs or CPs

Study for nuclear power reactors.

95-47 Unexpected Opening of a 10/04/95 All holders of OLs or CPs

Safety/Relief Valve and for nuclear power reactors.

Complications Involving

Suppression Pool Cooling

Strainer Blockage

95-46 Unplanned, Undetected 10/06/95 All holders of OLs or CPs

Release of Radioactivity for nuclear power reactors.

from the Exhaust Ventilation

System of a Boiling Water

Reactor

95-12, Potentially Nonconforming 10/05/95 All holders of OLs or CPs

Supp. 1 Fasteners Supplied by for nuclear power reactors.

A&G Engineering II, Inc.

95-45 American Power Service 10/04/95 All holders of OLs or CPs

Falsification of American for nuclear power reactors.

Society for Nondestructive

Testing (ASNT) Certificates

95-44 Ensuring Compatible Use of 09/26/95 All Radiography Licensees.

Drive Cables Incorporating

Industrial Nuclear Company

Ball-Type Male Connectors

95-43 Failure of the Bolt-Locking 09/28/95 All holders of OLs or CPs

Device on the Reactor for nuclear power reactors

Coolant Pump Turning Vane designed by Westinghouse

Electric Corporation (W).

95-42 Commission Decision on the 09/22/95 All holders of OLs or CPs

Resolution of Generic for nuclear power reactors.

Issue 23, "Reactor Coolant

Pump Seal Failure"

OL = Operating License

CP = Construction Permit

I

9--' IN 95-49 October 27, 1995 This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

orig /s/'d by DMCrutchfield

Dennis M. Crutchfield, Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contact: Hans Ashar, NRR

(301) 415-2851 Attachment:

List of Recently Issued NRC Information Notices

DOCUMENT NAME: 95-49. IN

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DATE 08/18/95 03/03/95 03/07/95 03/13/95 03/15/95 OFFICE D/DE I ADM:PUB IN OECB:DOPS I C SC/OECB:DOPS N PECB:DRPM E

NAME BSheron* Tech Ed* JCarter* RDennig* RKiessel*

DATE 03/21/95 04/0495 j 95 04/05/95 09/20/95 OFFICE C/PECB:DRPM N D/D I I I

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DATE 09/22/95 10/Z /95 OFFICIAL RECORD COPY

IN 95-XX

September xx, 1995 This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Dennis M. Crutchfield, Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contact: Hans Ashar, NRR

(301) 415-2851 Attachment:

List of Recently Issued NRC Information Notices

9fr?/96 - 7~'*t di gu4 DOCUMENT NAME: G:\ATB1\TLGINF04.HGA e

d//e and0

,~/ Y/45:/ .

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To receive a copy of this document. Indicate In the box: ACT

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DATE 9q,;.z /95 / /95 OFFICIAL RECORD COPY

-' IN 95-XX

August xx, 1995 This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Dennis M. Crutchfield, Director

Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical contact: Hans Ashar, NRR

(301) 415-2851 Attachment:

List of Recently Issued NRC Information Notices

DOCUMENT NAME: G:\ATB1\TLGINF04.HGA

• See previous concurrence

To isceive a copy of this document, Indicate In the box: TIC - Copy without attachment/enclosure 'E'

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lDATE 19/ Ig /9J 03/03/95 103/07/95 03/13/95 03/15/95 OFFICE D/DE N ADM:PUB IN OECB:DOPS C SC/OECB:DOPS N PECB:DRPM

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OFFICIAL RECORD COPY

'~' 9IN 95-XX

May xx, 1995 This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Project Support

Office of Nuclear Reactor Regulation

Technical contact: Hans Ashar, NRR

(301) 415-2851 Attachment:

List of Recently Issued NRC Information Notices

DOCUMENT NAME: G:\IN\SEISMIC.IN

• See previous concurrence

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[NAME

OFFICE

DATE

ECGB:DE

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/ /95 EC D

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[OFFICE D/DE IN ADM:PUB N OECB:DOPS C SC/OECB:DOPS IN OECB:DOPS

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IN 95-20

March 22, 1995 This information notice requires no specific action or written response. If

you have any questions about the information in this notice, contact the

technical contact listed below, or the appropriate project manager in the

Office of Nuclear Reactor Regulation (NRR).

Brian K. Grimes, Director

Division of Project Support

Office of Nuclear Reactor Regulation

Hans Ashar, NRR

(301) 415-2851 Attachment:

List of Recently Issued NRC Information Notices

• See previous concurrence DOCUMENT NAME: G:\TJC\TLGINFON.HGA

Tn rpcive aAnnV nf this rindjnugnt Iwnic*te in the box C=ComY w/i attahhmpnten~ctnsur F=NCOnv with attachm-nt/anclagure M .3 i copy

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