ML19309F136
| ML19309F136 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 04/22/1980 |
| From: | Moody D YANKEE ATOMIC ELECTRIC CO. |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| References | |
| WYR-80-45, NUDOCS 8004280534 | |
| Download: ML19309F136 (4) | |
Text
i Telephone 617 366-90ll
[
Twx 710 390-0739 YANKEE ATOMIC ELECTRIC COMPANY 8.4.1.1 WYR 80-45
,Yaux]se, QL Ui 20 Turnpske Road Westborough, Massachusetts 01581 April 22, 1980 United States Nuclear Regulatory Commission Washington, D.C. 20555 Attention:
D. L. Ziemann, Chief Operating Reactors Branch #2 Division of Operating Reactors
References:
(a)
License No. DPR-3 (Docket No. 50-29)
(b) YAEC Letter WYR 79-44 dated April 10, 1979, Subjent:
Penetrating Fire Barriers (c) USNRC Letter dated March 24, 1980, from D. L. Ziemann to J. A. Kay,
Subject:
Fire Barrier Qualification Testing
Dear Sir:
Subject:
Fire Barrier Qualification Testing Yankee Atomic Electric Company has reviewed the attachment to Referenec (c) above. Our analysis and discussion showing our conclusions that the deviations stated in Reference (c) do not significantly affect the test results, are attached for your review.
We trust that they meet with your approval.
If you have any further comments or questions, please contact us.
Very truly yours, YANKEE ATOMIC ELECTRIC COMPANY
.b.
D. E. Moody Manager of Operations EAS/see l
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800428 0 g39
1 ATTACHMENT 1 Yankee Atomic Electric Company has reviewed the five exceptions that the NRC staff noted as existing between the procedure used to test cable penetration fire barriers similar to those used at Yankee Rowe and the recommended NRC procedure. We will address each exception below.
1.
Exception: There is no requirement that the test arrangement be representative of the worst case configuration of cable loading, cable tray arrangement, anchoring, and penetration fire barrier and size.
Response
Cable loading through fire barrier penetrations at Yankee Rowe does not exceed 100%. Thus, it is our contention that the test loading called for meets or exceeds our worst case. The cable tray configuration at Yankee Rowe does not exceed the configurations called for in the NELPIA/MAERP test. In only two cases in the plant are the penetration fire barrier size and design different from those tested in the NELPIA/MAERP tests. Between the switchgear and the control room are two penetrations, one up into the Control Board and one along the back wall of the Control Room. Because of the size and configuration of these seals, no test was possible. However, the supplier submitted data on penetrations similar to them to American Nuclear Insurers, who then did a careful analysis of the similarities and differences, eventually accepting the penetration seals as adequate. There is no special anchoring system for cable tray at Yankee Rowe.
It is similar to that used in many of the tests run by the supplier.
2.
Exception: There is no requirement that cable sizes be representive of cable sizes in the facility.
Response: Cable sizes used in the tests were:
(1) No. 16, two conductor, (2) No. 12, 7 conductor, and (3) 1/c 300MCM cable. These are representative of the range of cables used in our facility, where the largest used are 1/c 350MCM and No. 16, 37 conductor.
3 Exception:
There is no requirement to test in both directions if the fire barrier is not symetrical.
Response
Fire barriers at Yankee Rowe are symetrical.
4.
Exception: There is no requirement to test with a pressure differential across the penetration seal.
l
Response
As stated many times before by many people, this l
requirement has been beyond the state of the art up to the present time for most test facilities. To our knowledge, tests that are currently underway still do not conform to this requirement.
It is l
not a requirement of any test except that of the NRC.
It should not be a present requirement and much more study should be done before it becomes one in the future.
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1 5.
Exception:
There exists no requirement to monitor the temperature
/
levels of cable insulation, cable conductor, cable tray, conduit and fire stop material on the unexposed side. The only requirement is that no individual thermocouple exceed 3250F above ambient temperature, which may not be conservative.
Response
Examination of the drawing showing placement of the thermocouples for the NELPIA/MAERP test will show that temperature measurements are made:
(1) on the six inch steel conduit, (2) inside the six inch conduit or the cable insulation, (3) at several locations on the fire stop material, some of which are extremely close to the cable tray itself, and (4) on the barrier itself. The only point that is not measured is the cable conductor. This one difference in thermocouple placement should not invalidate the test results, especially when the conservatism designed into penetration seals is so well known.
Three sets of Acceptance Criteria for a successful test are listed below. The first is that of the NRC staff, the second is that listed in IEEE 634-1978, Standard Cable Penetration Fire Stop Qualification Test, the third is that listed in the NELPIA/MAERP test.
1.
NRC - The test is successful if:
a.
The cable penetration fire barrier has withstood the fire endurance test without passage of flame or ignition of cables on the unexposed side for a period of three hours, b.
The temperature levels recorded for the unexposed side are analyzed and demonstrate that the maximum temperature is sufficiently below the cable insulation ignition temperature, and c.
The fire barrier remains intact and does not allow projection of water beyond the unexposed surface during the hose stream test.
2.
IEEE 634-1978 6.1 Acceptance. The test can be considered acceptable and the cable penetration fire stop suitable for use in accordance with the fire rating, provided the following is cet:
6.1.1 The cable penetration fire stop shall have withstood the fire endurance test as specified without passage of flame or gases hot enough to ignite the cable or other fire stop material on the unexposed side for a period equal to the required fire rating.
6.1.2 Transmission of heat through the cable penetration fire stop shall not raise the temperature on its unexposed surface above the self-ignition temperature as determined in ANSI K65.111-1971 of the outer cable covering, the cable penetration fire stop material, or material in contact with the cable penetration fire stop, when measured in accordance with 5 3 10 and 5.3.11.
For power generating station, the maximum temperature if 7000p, 1
L.
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i 6.1 3 The fire stop shall have withstood the hose stream J
test without the hose stream causing an opening through the test specimen.
3 NELPIA/MAERP - acceptance criteria:
a.
Fire shall not propagate to the unexposed side of the test assembly nor shall any visible flaming be observed.
b.
No individual thermocouple of the unexposed surface of the fire stop shall exceed 3250F above ambient temperature.
c.
No opening develops that permits a projection of water from the stream beyond the unexposed surface during the hose stream test.
Examination of the three sets of criteria show that there is not much difference amoung them. The staff concern that the NELPIA/MAERP limit on temperature may not be conservative can best be answered by looking at an exerpt of a Table from ANSI K65.111-1971. When these temperatures are compared to the "3250F above ambient" requirement of the NELPIA/MAERP test, it can clearly be seen that the requirement is a conservative one.
Material Flash-Ignition Self-Ignition Cotton 446-511 490 Newspaper 445 445 Pine Shavings 406-507 500 Wool 401 Polyethylene 645 660 Polyvinyl chloride 735 850 Polytetrafluoroethylene 986 Polyvinyl chloride-acetate 608-644 815-1035 Polystyrene 635-680 910-925 Nylon 66 750-790 788-806 Based upon the information above, it is our contention that the deviations from staff requirements do not signifcantly affect the test results. Therefore, there should be no requirement to perform additional tests.
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