ML20129D951
| ML20129D951 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 07/16/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20129D932 | List: |
| References | |
| NUDOCS 8507300204 | |
| Download: ML20129D951 (4) | |
Text
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r SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION OF PROPOSED ACCEPTANCE CRITERIA FOR FIRECODE CT GYPSUM FIRE STOPS COMMONWEALTH EDIS0N LASALLE COUNTY STATION UNITS 1 AND 2 r.
DOCKETS N05. 50-373 AND 50-374 Introduction By memorandum dated February 10, 1984, the licensee committed to the NRC to revise their Firecode CT Gypsum Fire Stop surveillance and installation procedures to incorporate a 1/32 inch acceptance criteria for cracks and separations.
This criteria was established based on a lack of test data supporting less stringent acceptance criteria.
On May 28, 1985 the licensee submitted revised acceptance criteria for cracks and separations based on newly obtained test data and requested NRC concurrence on the new criteria.
This Safety Evaluation documents the NRC review of the revised acceptance criteria and their impact on the operation and administration of plant activities.
Summary of Evaluation The evaluation of the licensee's revised criteria consisted of a comparison of e-the test methodology and results that form the basis for the revised criteria and the specifications contained in Branch Technical Position CMEB 9.5-1 Section C.Sa(3) including ASTM E110-81 as endorsed by Standard Review Plan Section 9.5-1.
The staff found the proposed changes acceptables.
s Evaluation of Proposed Change to Crack and Separetion Criteria DescriDtion of Change I
Existing cri,te.ria require cracks and separations greater than 1/32 inch wide,
to be repaired.
Wi'er cracks would cause the affected seal.to be declared d
The following revised criteria are proposed:
a.
Following initial seal installation or repair:
d' l
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Crack Width Corrective Action
< 3/32 inch None 1 3/32 inch Seal unacceptable -
repairs required b.
Periodic surveillance acceptance criteria:
Crack Width Corrective Action
< 5/32 inch None
> 5/32 inch and < 1/4 inch Seal is operable but must be repaired on an orderly schedule 1 1/4 inch Seal inoperable -
repairs required 8507300204 850716 PDR ADOCK 05000373 p
Evaluation i
\\
The basis for the revised criteria is a test performed by Transco Products Inc. on November 20, 1984 and documented in Transco Test Report Ho. TR-161.
Two test configurations were used to demonstrate seal performance ~with cracks.
Each configuration consisted of an opening 141/2 inches by 9 inches in a 12 inch thick concrete slab.
Each opening, containing a 2 fnch conduit, was filled with 5 inches of CT Thermafiber covered with 5 inches of Firecode CT Gypsum.
A 1/4 inch crack 14 1/2 inches long with full thickness penetration was induced in each seal. One seal was exposed to the test fire on the Firecode CT Gypsum side.
The second seal was exposed to the test fire on the CT Thermafiber side.
The test fire was provided by a natural gas-fired furnace measuring 4 feet by 4 feet at its support points.
Furnace atmosphere temperatures were monitored
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by three thermocouples 12 inches below the test seal.
Average pressure during the test was.08 inches of water negative.
Thermocouples were placed on the side of the seal away from the fire as follows:
a.
Seal with CT Thermafiber exposed to the fire:
1.
Two thermocouples slightly depressed into the CT Gypsum surface.
2.
One thermocouple suspended in the 1/4 inch crack slightly below the CT Gypsum surface.
3.
One thermocouple at the conduit exit - seal interface.
b, Seal with CT Gypsum exposed to the fire:
il t
1.
One thermocouple slightly depressed into the CT Thermafiber surface.
2.
One thermocouple on the CT Thermafiber surface directly over the 1/4 inch crack in the CT Gypsum.
3.
One thermocouple at the conduit exit seal interface.
Additional thermocouples were installed to monitor seal performance.inside ths conduits.
'e Seal temperatures were recorded at 5 minute intervals for the first two hours of the test and at 10 minute intervals for the last hour of the test.
At the conclusion of the fire exposure test the seals were subjected to three separate hose stream tests.
The first two tests consisted of a 75 psi hose stream delivered from a distance of 10 feet through a 1 1/2 inch hose equipped with fog nozzles with discharge angles of 30 and 15.
The third test consisted of a 30 psi solid stream delivered through a 2 1/2 inch hose equipped with a 1 1/8 inch tip set on a playpipe from a distance of 20 feet.
Each test lasted 24 seconds.
The following test results were obtained:
2
a.
The maximum temperature attained over the crack in the seal with the CT Gypsum exposed to the fire was 140 at 20 minutes into the test.
The maximum seal surface temperature attained was 129 F at 25 minutes into the test.
The maximum conduit exit-seal interface temperature attained in this configuration was 272* F at the 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> point.
b.
The maximum temperature attained over the crack in the sealswith CT fiberfill exposed to the fire was 80 F at the 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> point.
The maximum seal surface temperature attained was 118 F at the 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> point.
The maximum conduit exit - seal interface temperature attained was 205* F at the three hour point.
c.
The seal with the CT Gypsum side exposed to the fire passed all three hose stream tests with no water penetration.
d.
The seal with the CT fiberfill side exposed to the fire passed the first two hose stream tests without water penetration.
Water penetration was observed on the, third test.
e.
No flame penetrated.either seal nor did any penetrating cables ignite on the unexposed side of the seal.
Standard Review Plan Section 9.5-1 references Section C.5.a(3) of the Branch
" ' ~
Technical Position (BTP) CHEB 9.5.1, " Fire Protection for Nuclear Power Plants",
which specifies testing requirements for fire seals installed in openings through fire barriers.
The BTP specifies that seals be tested using the time temperature exposure curve of ASTM E-119.
The acceptance criteria specified are:
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.a.j The fire barrier penetration has withstood the fire endurance tests without passage of flame or ignition of cab,les on the unexposed side.
b.
The maximum temperature reached on the unexposed side of the seal is 325 F.
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df The penetration seal remains intact and does not allow penetration of water beyond the unexposed surfaces during one of the fjollowing three tests:
r 1.
Stream delivered at a distance of 5 feet from t.he exposed surface through a 1 1/2 inch nozzle set at a discharge angle of 30 With a nozzle pressure of 75 psi and a minimum flow of 75 gpm or 2.
Stream delivered at a distance of 10 feet from the exposed surface through a 1 1/2 inch nozzle set at a discharge angle of 15 with a nozzle pressure of 75 psi and a minimum flow of 75 gpm or 3.
Stream delivered at a distance of 20 feet from the exposed surface through a 2 1/2 inch playpipe equipped with a 1 1/8 indh tip with a nozzle pressure of 30 psi.
3
Review of the Transco Products, Inc. test results and methodology against the acceptance criteria of the Standard Review Plan showed the following:
4 a.
The time temperature curve utilized for the test conformed to ASTM E-119 specifications.
b.
The flame through and cable ignition criteria were satisfie'd'.
c.
The maximum unexposed surface temperatures remained below the 325*
specified value.
d.
Temperature recording requirements were satisfied.
i e.
The tested configuration is representative to the as-installed i
configurations at LaSalle.
4 f.
Hose stream tests performed in accordance with Items 1 and 2 above were successfully completed.
A single successful test would have been
' sufficient.
Thus, minimum hose stream test requirements were met or exceeded.
Given that the tested seal configuration with a 1/4 inch crack passed all required tests and bounds the seal configuration at LaSalle and the licensee's r- -
proposed crack and separation criteria, the staff finds the proposed criteria acceptable.
Environmental Consideration The proposed changes involve a change in the-i64tallation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The' staff has determined that the changes involve no significant increase in the amounts, and no significant change in the types of any effluents that may be relhased offsite, and that there is no significant increase in individual ~
or cumulative occupational radiation exposure.
Pursuant to 10 CFR 51.22(b) no environmental (impact statement or environmental assessment need be prepared in
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connection with the' proposed changes.
1-Conclusion n
The staff has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Commission's regulations and will not be inimical to the common defense and security or to the health and safety of the public.
Dated:
Principal Contributor W. G. Guldemond 4
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