ML19254F810
| ML19254F810 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 10/17/1979 |
| From: | Lainas G Office of Nuclear Reactor Regulation |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7911190095 | |
| Download: ML19254F810 (5) | |
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UN;TED STATES
[j *, ;%j NUCLEAR REGULATORY COMMISSION i
E WASHINGTON, D. C. 20555
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Oci 7ca MEMORANDUM FOR:
R. Reid, Chief, Operating Reactors Branch #4, 00R FROM:
G. Lainas, Chief, Plant Systems Branch, COR
SUBJECT:
FIRE PROTECTION - CALVERT CLIFFS 1 AND 2 - TEST PROCEDURES TO QUALIFY CABLE AND PIPE PENETRATIONS Facility: Calvert Cliffs Nuclear Pcwer Plant Licensee:
Baltimore Gas and Electric Company Docket No. : 50-317 and 50-318 Responsible Branch: CRS#4 Project Manager:
E.L. Conner Reviewing Branch: Plant Systems Branch Status: SER Issued; Evaluation of Incomolete Items On-going We have reviewed the procedures entitled, " Test to Qualify Cable and Pipe Penetrations in Fire Walls and Floors for Calvert Cliffs Nuclear Power Plant *, which was provided with the licensee's letter dated S'eptember 14, 1979. Our comments are listed in the enclosure. We approve the crocedures subject to a satisfactory resolution of these comments. A meeting between the staff and SG&E to resolve these coments should be arranged within two weeks.
This test is to demonstrate the fire rating of the cable and pi::e penetrations and the ability of certain electrical cables contained in steel conduit to remain functional during and after a fire as simulated by the ASTM E-119 time-temperature characteristic.
The licensee is requested to notify the Comission of the test date at least 30 days in advance, so that tne staff can witness and verify the test. We also request that a full test report be submitted for the staff's evaluation following the test.
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G. Lainas, Chief Plant Systems Branch Division of Ccerating Reactors cc: See page 2 1 M 4 196 7 911190 07 $
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Enclosure:
List of Coments
Contact:
T. Lee X-27878 cc w/ enclosure:
D. Eisenhut S. Grimes W. Gannill R. Ferguson G. Lainas E. Conner T. Lee D. Notley G. Harrison E. Sylvester T. Wambach V. Ebnaraya J. Klevan (Consultant)
E. Ma Ocugall (BNL)
R. Hall (BNL) e l?44 197 w
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ENCLOSURE e
CALVERT CLIFFS NUCLEAR POWER PLANT COCKET NOS. 50-317, 50-318 CCMMENTS ON TEST PROCEDURES 1.
It a3 pears that the results of one or two tescs will be applied throaghout the plant; therefore, each of the test variables should reflect the most conservative condition among all plant areas. The following considerations as proposed in the licensee's crocedure did not appear to be conservative:
A) Trav Fill (C-5)*
Caele loading of 50% in trays was proposed while in many plant areas tray fill in excess of 100% was observed.
Verify that the 50% cable tray load is conservative.
B),Tyce of Cables (C-5)
Silicone rubber insulated, glass braid covered, and asbestos braid jacketed cables were proposed for the test to qualify the electrical penetration seal while the plant is known to have many non-silicone rubber cables (see Section 4.8 of NRC's Fire Protection SER).
By the licensee's previous test results, silicone rubber cables were shown to have a better fire retardant characteristics than conventional electrical cables; test results cualifying silicone rubber cable penetrations, therefore, will not be applicable to non-silicone rubber cable penetrations.
The licensee is requested to include a provision in the test which wili cualify
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non-silicone rubber cable penetrations.
C) Slab Thickness (Fig. 1)
A minimum of 2 feet thick wall or fl or was proposed as the test assembly. We request the licensee to verify that there is not a wall or a floor in tne piant that is less than 2 feet tnick and is penetrated by electrical cables.
- 0) Test Configuration (cover letter)
It was :rocesed that the penetration assembly will be tested in the heri:Ontal or floor configuration to cuality both wall and ficcr fire stop design. We agree that floor configuration is more c:nservative; hcwever, the wall and the flocr enetratiors in Calvert Clif's have different designs. The licensee is requested to include some wall penetration design (witnout Ver-iculite voit fill) in the norizontal configuration to cuality tne wall :enetrations.
"The number noted in the carentheses re#er to the section in the licensee's procedure.
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2 E) Picing Penetrations (C-8)
It was indicated that the pipe penetration will utilize 6" diameter pipe and 10" diameter sleeve. We request the licensee to verify: (i) if all piping penetrations have sleeves; and (ii) if 6" pipe and 10" sleeve corresconds to the worst configuration in the plant. A larger sleeve and/or a smaller pipe is believed to represent a worse configuration.
2.
The test procedure did not specify the pressure differential to be maintained across the cenetrations.
Verify that a positive pressure differential will be maintained to simulate a fire si tua tion.
3.
Conduit Assembly A) The off-gassing of cables inside conduits may induce a fire in the terminai switen box outside the fire area which has an ignition source. A provisicn should be included in the test to demonstrate that the off-gassing of cables in the conduit will not cause a fire in the terminal switch box.
S) Testing the conduit of only two feet is unrealistic and non-conservative because it does not simulate differential expansions, off-gassing and changes in conductor and insulation resistance; we recomend a configuration similar to that shown below be tested. Sharp turns should be included. Verify that the new length and configuration provide a realistic simulation of pe plant conduit configuration.
(C-6) 9:c '
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4 Test Duration (E-3)
Since seme cables required for the long ter n cooling may be required to function up to 30 days following the fire, the test should demonstrate that the function of electric circuits can be maintained not only before, during and right after the fire, but also a reasonable period of time thereafter, exposing the cables and the conduit to an atmosphere similar to that following a fire.
5.
The test should include certain provisions to demonstrate that mechanical disturbances, (e.g., impact) generally expected in fire fighting and other cossible activities subsecuent to the fire, on the conduit will not disable the function of the cables.
6.
Hose Stream Test (D-2)
The hose stream with the no::le discharge angle of 300 is proposed for the hose stream test. This stream while it is acceptable to the area equipped with a spray no::le, may not be conservative in the areas where spray no::les are not provided. Saecifically, it is unlikely that spray no::les are orovided for all areas where pipe penetrations exist.
Testing the piping penetration with the proposed hose stream, therefore, is not conservative. Straight stream should be used to qualify penetrations located in areas protected by hoses equipped with the regular no::le.
7.
Provide an analysis which verifies that changes in conductor and insulation resistance during a fire will not cause circuit mal func tions.
8.
Describe the post test inspections and criteria to be used to determine that the cable is still functional and the length of the cable can be expected to remain functional. Provide a brief description of the procecure to be used to replace the damaged cable following a fire.
9.
The circuit integrity test should include a provision to verify that switening transients will not have an adverse effect in maintaining the electrical function of the cable.
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