Information Notice 1992-82, Results of Thermo-Lag 330-1 Combustibility Testing

Results of Thermo-Lag 330-1 Combustibility Testing

ML031190738
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:	12/15/1992
From:	Grimes B Office of Nuclear Reactor Regulation
To:
References
IN-92-082, NUDOCS 9212090211
Download: ML031190738 (17)

\. - - v- UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 December 15, 1992 NRC INFORMATION NOTICE 92-82: RESULTS OF THERMO-LAG 330-1 COMBUSTIBILITY

TESTING

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

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

notice (IN)to alert addressees to the results of Thermo-Lag 330-1 combustibility tests conducted for the NRC by the National Institute of

Standards and Technology (NIST). It is expected that recipients will review

the information for applicability to their facilities and consider actions as

appropriate. However, suggestions contained in this information notice are

not new NRC requirements; therefore, no specific action or written response is

required.

Description of Circumstances

As part of a small-scale testing program of Thermo-Lag 330-1 fire barrier

material, NRC staff had NIST perform combustibility tests using the following

standards: (1) American Society for Testing and Materials (ASTM) E-136,

"Standard Test Method For Behavior of Material in a Vertical Tube Furnace at

750 'C;" and-(2) ASTM E-1354, "Standard Test Method for Heat and Visible Smoke

Release Rates for Materials and Products using an Oxygen Consumption

Calorimeter." NIST documented the results of these tests in Attachment 1,

"Report on Test FR 3989, Analysis Of Barrier Material For Noncombustibility,"

of August 31, 1992.

Based on the ASTM E-136 testing standard, the NIST tests revealed that

Thermo-Lag 330-1 fire barrier material is combustible. This testing standard

prescribes the mAterial as combustible if three out of four samples exceed any

of the following criteria: (1) the recorded temperature of the specimen's

surface and interior thermocouples rise 30 0C [54 OF] above the initial

furnace temperature; (2) there is flaming from the specimen after the first

30 seconds of irradiance; or (3) the weight loss of the specimen during

testing exceeds 50 percent and either (a) the recorded temperature of the

surface and interior thermocouples at any time during the test rise above the

furnace air temperature at the beginning of the test or (b) there is flaming

of the specimen. Each of the four Thermo-Lag specimens tested exhibited a

weight loss of greater-than 50 percent and exhibited flaming beyond 30

seconds.

921209021

IN 92-82 .

December 15, 1992 NIST performed the ASTM E-1354 calorimeter test on four Thermo-Lag specimens, subjecting them to an irradiance of 75 kW/m 2 [6.6 BTU/ft2 -s]. The total

amount of heat released from the Thermo-Lag exceeded that released from Gypsum

board and was about equal to the heat released from fire-retardant plywood.

Discussion

Section 50.48(a) of Title 10 of the Code of Federal Regulations requires that

each operating nuclear power plant have a fire protection plan that satisfies

General Design Criterion (GDC) 3, "Fire protection," in Appendix A to 10 CFR

Part 50. GDC 3 requires that "structures, systems, and components important

to safety shall be designed and located to minimize, in a manner consistent

with other safety requirements, the probability and effects of fires and

explosions. Noncombustible and heat resistant materials shall be used

wherever practical throughout the unit, particularly in locations such as the

containment and control room."

NRC-approved plant fire protection programs referenced by the plant operating

license and Section III.G, "Fire protection of safe shutdown capability," of

Appendix R to 10 CFR Part 50, require one train of systems necessary to

achieve and maintain hot shutdown conditions from either the control room or

emergency control stations to be free from fire damage:

Section III.G.2 of Appendix R permits separation by a horizontal distance of

more than 6.1 meters [20 feet] with no intervening combustibles or fire

hazards as one of several methods to ensure that cables and equipment and -

associated circuits of redundant safe shutdown trains located outside

containment are maintained free from fire damage. If this method is used, fire detection and automatic fire suppression must be installed in the area of

the redundant safe shutdown trains. 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 the redundant

safe shutdown trains.

Section III.G.2.f of Appendix R allows licensees to separate cables and

equipment and associated circuits of redundant trains inside noninerted

containments by installing a noncombustible radiant energy shield as one of

several methods to achieve required fire protection for these circuits. Some

licensees use Thermo-Lag to construct radiant energy heat shields inside

containment.

Related Generic Communications

Attachment 2 is a list or recently issued generic communications concerning

Thermo-Lag 330-1 fire barrier systems.

. i I

IN 92-82 December 15, 1992 This information notice requires no specific action or written response. If

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

one of the technical contacts listed below or the appropriate Office of

Nuclear Reactor Regulation (NRR) project manager.

Original signed by

Brian K.Grimes

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contacts: Ralph Architzel, NRR

(301) 504-2804 Patrick Madden, NRR

(301) 504-2854 Attachments:

1. Report of Test FR 3989, Analysis Of

Barrier Material For Noncombustibility

2. List of Recently Issued Generic

Communications Concerning Thermo-Lag 330-1 Fire Barrier Systems

3. List of Recently Issued NRC Information Notices

• See previous page for concurrence

SPLB:DSSA SPLB:DSSA TechEd OIG

MWidmann* RArchitzel* JMain* GMulley*

11/04/92 11/04/92 11/05/92 11/05/92 SPLB:DSSA DD:DSSA D:DSSA C/OGCB:DORS:NRR

CMcCrackei GHolahan* AThadani* GMarcus*

11/05J,'2 , 11/10/92 11/08/92 11/25/92

121/p /92 DOCUMENT NAME: 92-82. IN

11'

IN 92-XX

November xx, 1992 This information notice requires no specific action or written response. If

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

one of the technical contacts listed below or the appropriate Office of

Nuclear Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contacts:

Ralph Architzel, NRR

(301) 504-2804

Patrick Madden, NRR

(301) 504-2854 Attachments:

1. Report of Test FR 3989, Analysis Of Barrier Material For Noncombustibility

2. List of Recently Issued Generic Communications Concerning Thermo-Lag 330-1 Fire Barrier Systems

3. List of Recently Issued NRC Information Notices

• See previous page for concurrence

SPLB:DSSA SPLB:DSSA TechEd OIG

MWidmann* RArchitzel* JMain* GMulley*

11/04/92 11/04/92 11/05/92 11/05/92 SPLB:DSSA DD: DSSA D: DSSA C/OGCB:DORS:NRR

CMcCracken* GHolahan* AThadani* GMarcus Om

11/05/92 11/10/92 11/08/92 1i.1/ ,:r4bW

DORS:NRR

BGrimes

11/ /92

[G:\THERMOLA\INCOMBUS.MTW]

al

IN 92-XX

November xx, 1992 This information notice requires no specific action or written response. If

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

one of the technical contacts listed below or the appropriate Office of

Nuclear Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contacts: Ralph Architzel, NRR

(301) 504-2804 Patrick Madden, NRR

(301) 504-2854 Attachments:

1. Report of Test FR 3989, Analysisi6 f

Barrier Material4mor Noncombustibility

2. List of Recently Issued Generic

Communications Concerning Thermo-Lag 330-1 Fire Barrier Systems

3. List of Recently Issued NRC Information Notices

• See previous page for concurrence

SPLB:DSSA SPLB:DSSA TechEd OIG

MWidmann* RArchitzel* JMain* GMulley*

11/04/92 11/04/92 11/05/92 11/05/92 SPLB:DSSA DD:DSSA D: DSSA C/OGCB:DORS:NRR

CMcCracken* GHolahan* AThadani* GMarcusc 7 (

11/05/92 11/10/92 11/08/92 111v%792 DORS:NRR

BGrimes e

11/ /92

[G:\THERMOLA\INCOMBUS.MTW]

IN 92-XX

November xx, 1992 This information notice requires no specific action or written response. If

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

one of the technical contacts listed below or the appropriate Office of

Nuclear Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contacts: Ralph Architzel, NRR

(301) 504-2804 Patrick Madden, NRR

(301) 504-2854 Attachments:

1. Report of Test FR 3989, Analysis of

Barrier Material for Noncombustibility

2. List of Recently Issued Generic

Communications Concerning Thermo-Lag 330-1 Fire Barrier Systems

3. List of Recently Issued NRC Information Notices

• See previous page for concurrence

SPLB:DSSA SPLB:DSSA TechEd OIG

MWidmann* RArchitzel* JMain* GMulley*

11/04/92 11/04/92 11/05/92 11/05/92 SPLB:DSSA DD:DSSA D:DSSA C/OGCB:DORS:NRR

CMcCracken* GHolahan* AThadani* GMarcus*

11/05/92 11/10/92 11/08/92 11/25/92 DORS:NRR

BGrimes

11/ /92

[G:\THERMOLA\INCOMBUS.MTW]

-3- This information notice requires no specific action or written response. If

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

one of the technical contacts listed below or the appropriate Office of

Nuclear Reactor Regulation (NRR) project manager.

Brian Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Attachment:

1. Report of Test FR 3989, Analysis Of Barrier Material For Noncombustibility

2. List of Recently Issued Information Notices

Technical contacts: Ralph Architzel, NRR

(301) 504-2804 Patrick Madden, NRR

(301) 504-2854 TechEd OIG do txr

JMain 0;8 GMu 11ey r SCUC. D

Vz>

11/5-/992 I11/_5/92 D: DSSAAT C/OGCB:DORS:NRR

AThaPnhi GMarcus

11/ 1J/92 11/ /92 DORS:NRR

BGrimes

11/ /92

[G:\THERMOLA\INCOMBUS.MTW]

_J -

IN 92-82 December 15, 1992 This information notice requires no specific action or written response. If

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

one of the technical contacts listed below or the appropriate Office of

Nuclear Reactor Regulation (NRR) project manager.

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contacts: Ralph Architzel, NRR

(301) 504-2804 Patrick Madden, NRR

(301) 504-2854 Attachments:

1. Report of Test FR 3989, Analysis Of

Barrier Material For Noncombustibility

2. List of Recently Issued Generic

Communications Concerning Thermo-Lag 330-1 Fire Barrier Systems

3. List of Recently Issued NRC Information Notices

Attachment 1 IN 92-82 December 15, 1992 U.S. DEPARTMENT OF COMMERCE

NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY

Gaithersburg, MD 20899 REPORT OF TEST

FR 3989 on

ANALYSIS OF BARRIER MATERIAL FOR NONCOMBUSTIBILrTY

by

Vytenis Babrauskas

August 31, 1992 Submitted to:

Office of Nuclear Reactor Regulation

United States Nuclear Regulatory Commission

Washington, DC 20555

Attachment 1 IN 92-82

Purpose

of test December 15, 1992 Tests were conducted to determine if material submitted qualifies as noncombustible.

Material tested

The test material comprised board stock supplied by the Nuclear Regulatory Commission

(NRC) to

the National Institute of Standards and Technology (NIST). Two variations of board

stock were

supplied: nominal 1/2" and nominal 1" thick boards. The thickness of the boards is intended

by the

manufacturer to have a certain 'plus' tolerance, but a zero 'minus' tolerance. Thus, the

boards were

generally thicker than the nominal 12.5 and 25 mm values, but with substantial variation

from point

to point on the board. The nominal 1" stock contained a stainless steel wire mesh on

both sides of

the board, while the nominal 1/2" stock contained only wire mesh on one side of the board.

With the exception of removing the wire mesh (in those instances where stated, below)

and cutting

specimens to size, NIST did not alter or modify the specimens.

Definition of noncombustibility

A.

Ai

The Uniform Building Code (International Conference of Building Officials, Whittier, CA, 1991)

defines noncombustible as follows (pp. 29-30):

"Sec. 415. NONCOMBUSTIBLE as applied to building construction materials means

a

material which, in the form in which it is used, is either one of the following

(a) Material of which no part will ignite and burn when subjected to fire. Any material

conforming to U.B.C. Standard No. 4-1 shall be considered noncombustible within

the

meaning of this section.

(b) Material having a structural base of noncombustible material as defined in Item

(a) above, with a surfacing material not over 1/8 inch thick which has a flame-spread rating

of 50 or less."

We note that U.B.C. Standard No. 4-1 is functionally identical to ASTM E 136 [1]. The

other two

U.S. model building codes, BOCA National and Southern Standard, use essentially

identical

definitions for noncombustibility.

To explain in more detail, U.S. practice provides for two different ways by which a product

can be

qualified as noncombustible. Part (b) was originally developed to make certain that conventional

gypsum wallboard would be allowed as noncombustible. To qualify under part (b), two tests

must be

run: an ASTM E 136 test on the substrate material and the ASTM E 84 Steiner Tunnel

on the

complete product, including its thin surface layer. Part (b) cannot be successfully applied

to a product

unless the material comprising all of its thickness, save the topmost 1/8", can pass the ASTM

test, while the top layer cannot. In the present case, the steel mesh layer is accepted E 136 to be

noncombustible. Thus, for the test specimens submitted, part (b) is not applicable. Only testing

of the

bulk board stock material needs to be done, and this must be done using the ASTM E

136 test.

For reference, a specimen is recorded as passing the ASTM E 136 test if:

"...at least three of the four specimens meet the following conditions:

2

Attachment 1 IN 92-82 December 15, 1992 Page 3 Of 6 The recorded temperature at the surface and interior thermocouples do not at any time

during the test rise more than 54'F (300C) above the furnace temperature at the beginning

of the test, There is no flaming from the specimen after the first 30 s, and

When the weight loss of the specimen during the testing exceeds 50o, the recorded

temperature of the surface and interior thermocouples do not at any time during the test rise

above the furnace air temperature at the beginning of the test, and there is no flaming of the

specimen."

To examine the submitted specimens for noncombustibility, the standard procedure as described

above was conducted. To obtain additional information, some supplementary tests were also

conducted to better assay the behavior of the material. The standard procedure was conducted for

NIST under contract by United States Testing Company, Inc. Their results are described below, while

their report submitted to NIST is appended to this Report. The supplementary tests were conducted

in our own laboratories.

Standard tests

Specimens of the nominal 1"board stock were submitted to the United States Testing Company, Inc.

for testing according to ASTM E 136 procedures.

The material FAILED the test, since, for all 4 specimens tested, the percent weight loss was greater

than 50% and flaming continued in excess of 30 s.

The report received from the testing laboratory is attached as the Appendix to this report.

Supplementary tests

The report from an ASTM E 136 test is recorded simply in pass/fail terms. To derive additional

insight into the behavior of the material, it is possible to conduct tests which provide a quantitative

measurement scale. Such a test is available in the form of the ASTM E 1354 test [2]. This is a heat

release rate (HRR) test and, as such, it provides time-resolved information on the combustion of a

specimen. In engineering terms, specimens which are 'noncombustible' are those which show low heat

release. This concept has not yet been introduced into the U.S. building codes, but it is in the process

of being approved for use in Canada [3] and U.S. usage is expected to come shortly thereafter. The

2 tentative decision in Canada is to use a test irradiance of 50 kWm- . Work has also been done at2 NIST on the development of this concept, with most of the studies being conducted at a 75 kW m

irradiance 14]. This heat-release-based approach conceptually simplifies the treatment of

combustibility, since a special two-part testing approach, necessary for the conventional method to

properly characterize gypsum wallboard, is no longer necessary. With this heat-release based

approach, a single method is adequate to characterize all materials, including gypsum boards.

For the supplementary examination of the subject material, tests were conducted at both 50 and 75 kW m-2 irradiance levels. The specimens were cut from the nominal 1/2W board stock to a size of 100

mm by 100 mm. The actual thickness of the board stock was found to be approximately 18 mm. In

all cases, the prescribed edge frame was used, since the material substantially intumesces.

3

ii, Attachment 1 IN 92-82 The test conditions and the test results are given in Table 1. December 15, 1992 Table 1. Results obtained in supplementary tests

Test Test rradiance Peak Total heat in Total heat in

no; condition kWim-2 HRR 600 s 900;

_ kW m-2 MJm-2M~ mf

5489 grid used; 50 74 - 34.1 wire mesh up

5490 grid used; 50 83 - 44.1 wire mesh up

5491 grid used; 50 74 - 28.2 wire mesh down

5492 grid used; 50 76 - 25.9 wire mesh down

5466 grid not used; 75 120 28.5 wire mesh up

5486 grid used; 75 107 46.9 wire mesh up

5487 grid used; 75 110 38.9 wire mesh down

5467 grid used; 75 100 35.3 wire mesh down

It is intended in the ASTM E 1354 test that the specimen surface condition be approximately planar.

Thus, with intumescing or deforming specimens, the testing laboratory needs to use a restraint grid

described in the standard or, if necessary, an alternate restraint technique to ascertain that specimen

deformations are not excessive. The notation "grid used/not used" refers to the restraint grid specified

in ASTM E 1354. In the present case, the test board stock had a wire mesh which can be considered

as also serving some restraint function. Thus, various combinations of standard grid and wire mesh

topside/bottomside location were tried to determine if there was a systematic effect of the restraint

condition used. The notation "wire mesh" refers to the wire mesh which comes as part of the subject

test specimen.

Interpretation of results

The above findings must be interpreted in the light of the performance of materials accepted for

use

as noncombustible. By examining the published data it can be seen that the following performance

for gypsum wallboard (unpainted, both regular and Type-X grades) is obtained.

4

Attachment 1 IN 92-82 December 15, 1992 Table 2. Published results on gypsum wallboard Page 5 Of 6 Irradiance Ref PeakHRR Total beat in Totalheat in

kWmk2' kW 600 s ..

.900 s, Mm

50 [3] 70- 103 - 4

75 [4] 97 4.2 The results of Table 1 can now be compared to those of Table 2 to determine more quantitatively

the differences between the tested product and gypsum wallboard. There are two bases of

comparison: the value of the peak HRR and the total heat released in the control period (600 s when

testing at 75 kW m-2; 900 s when testing at 50 kWn-2 ). The value of the peak HRR for the tested

board product is seen to be roughly similar to gypsum wallboard. The value of the total heat released, however, is more than 8 times higher. This quantitative measure is consistent with the qualitative

observation in the E 136 test that "flaming continued for the remainder of the test."

As a result of the Canadian study, Richardson and Brooks [3] made a proposed recommendation that

combustibility of materials can be grouped into categories, based on performance in the ASTM E

2

1354 test. In the highest category (#1), limits of 10 kW m 2 on peak HRR and 5 MInm- on the total

heat released would be set. This is intended to correspond to specimens which pass solely by means

of the ASTM E 136 test. In the next category (#2), would be gypsum wallboard and other products

which are currently qualified on the basis of the ASTM E 136 test for the core material, plus the

2 ASTM E 84 test on the finished product. For category #2, the limits are taken at 100 kW m- peak

HRR and 25 MJm-2 total heat released. For the present test specimens, the total heat released

exceeds 25 MJnm-2 in all cases; thus, by the proposed Canadian criteria, the test material would not

qualify to be rated in a class comparable to gypsum wallboard.

References

[1] Standard Test Method For Behavior of Materials in a Vertical Tube Furnace at 750 'C

(E 136). American Society for Testing and Materials, Philadelphia.

[2] Standard Test Method for Heat and Visible Smoke Release Rates for Materials and

Products using an Oxygen Consumption Calorimeter (E 1354). American Society for

Testing and Materials, Philadelphia.

[3] Richardson, L.R., and Brooks, M.E., Combustibility of Building Materials, Fire and

Materials. 15, 131-136 (1991).

[4] Babrauskas, V., North American Experiences in the Use of Cone Calorimeter Data for

Classification of Products, pp.89-103 in Proc. of the Intl. EUREFIC Seminar 1991, Interscience Communications Ltd, London (1991).

5

Attachment 1 I

I -

IN 92-82 December 15, 1992 Prepared by: APPROVED

\I Babraus (

C

i

Vytenis Babrauskas, Andrew J. Fowell

Chief, Fire Science and Engineering Division

L

6

Attachment 2 IN 92-82 December 15, 1992 List of Recently Issued Generic Communications Concerning

Thermo-Lag 330-1 Fire Barrier Systems

1. Information Notice 91-47, "Failure of Thermo-Lag Fire Barrier Material

to Pass Fire Endurance Test," August 6, 1991

2. Information Notice 91-79, "Deficiencies in the Procedures for Installing

Thermo-Lag Fire Barrier Materials," December 6, 1991

3. Information Notice 92-46, "Thermo-Lag Fire Barrier Material Special

Review Team Final Report Findings, Current Fire Endurance Tests, and

Ampacity Calculation Errors," June 23, 1992

4.Bulletin 92-01, "Failure of Thermo-Lag 330 Fire Barrier System to

Maintain Cabling in Wide Cable Trays and Small Conduits Free from Fire

Damage," June 24, 1992

5. Information Notice 92-55, "Current Fire Endurance Test Results for

Thermo-Lag Fire Barrier Material," July 27, 1992

6.Bulletin 92-01, Supplement 1, "Failure of Thermo-Lag 330 Fire Barrier

System to Perform Its Specified Fire Endurance Function,"

August 28, 1992

Attachment 3 IN 92-82 December 15, 1992 Page 1 of I

LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Information Date of

Notice No. Subject Issuance Issued to

92-81 Potential Deficiency 12/11/92 All holders of OLs or CPs

of Electrical Cables for nuclear power reactors.

with Bonded Hypalon

Jackets

92-80 Results of Thermo-Lag 12/07/92 All holders of OLs or CPs

330-1 Combustibility for nuclear power reactors.

Testing

92-79 Non-Power Reactor 12/01/92 All holders of OLs or CPs

Emergency Event Response for test and research

reactors.

92-78 Piston to Cylinder 11/30/92 Al 1 holders of OLs or CPs

Liner Tin Smearing on for nuclear power reactors.

Cooper-Bessemer KSV

Diesel Engines

92-77 Questionable Selection 11/17/92 All holders of OLs or CPs

and Review to Deter- for nuclear power reactors.

mine Suitability of

Electropneumatic Relays

for Certain Applications

92-76 Issuance of Supple- 11/13/92 All holders of OLs or CPs

ment 1 to NUREG-1358, for nuclear power reactors.

"Lessons Learned from

the Special Inspection

Program for Emergency

Operating Procedures

(Conducted October 1988 -

September 1991)"

92-75 Unplanned Intakes of 11/12/92 All holders of OLs or CPs

Airborne Radioactive for nuclear power reactors.

Material by Individuals

at Nuclear Power Plants

92-74 Power Oscillations at 11/10/92 All holders of OLs or CPs

Washington Nuclear for nuclear power reactors.

Power Unit 2 OL = Operating License

CP = Construction Permit

t

Federal Recycling Program