ML012340520
| ML012340520 | |
| Person / Time | |
|---|---|
| Issue date: | 08/22/2001 |
| From: | Mayfield M Division of Engineering Technology |
| To: | Marion A Nuclear Energy Institute |
| References | |
| GSI-168 | |
| Download: ML012340520 (2) | |
Text
August 22, 2001 Mr. Alexander Marion Director of Engineering Nuclear Generation Division Nuclear Energy Institute 1776 I Street, NW Suite 400 Washington, DC 20006-3708
SUBJECT:
TECHNICAL ISSUES RELATED TO ENVIRONMENTAL QUALIFICATION (EQ) OF LOW-VOLTAGE I&C CABLES
Dear Mr. Marion:
The purpose of this letter is to request an expedited response from the industry on several technical issues concerning environmental qualification of safety-related, low-voltage instrumentation and control cables. In the context of resolving GSI-168, the industry asked the staff whether the four technical issues concerning environmental qualification of safety-related, low-voltage instrumentation and control cables discussed at the NRC public meeting on April 12, 2001, were the only technical issues that remain open.
The staff believes that there are some additional concerns, as stated below, that need to be factored into the resolution of GSI-168. These concerns have been previously discussed during several public meetings and are summarized as follows:
! The significance of the Samuel Moore cable failures during the submerged voltage withstand test needs to be evaluated. It should be noted that (1) the cables successfully passed the LOCA phase of the test without failure, and (2) the failures in two specimens occurred during the submerged voltage withstand test due to dielectric breakdown at 1000 V and 1200 V AC (per IEEE Std. 383-1974, for 30 mil insulation the voltage withstand requirement is 30X80 V/mil = 2400 V AC). The NRC staff is interested in obtaining any industry information that may explain the failures and address the performance of multiconductor bonded-jacket Samuel Moore cables.
! Nine of twelve specimens (AIW, Samuel Moore, Rockbestos, and Okonite cables) failed the submerged voltage withstand test (after the cable specimens were pre-aged to an equivalent of 60 years and subjected to LOCA tests). The significance of these failures needs to be evaluated. Any industry information that may explain these failures would be useful for appropriate considerations in the resolution of GSI-168.
A. Marion ! While the LOCA test failures of Okonite single conductor bonded- jacket cables are being addressed separately, the generic implications of similar Okonite cables of different wire gauge size, and similar single conductor and multiconductor cables of other manufacturers need to be evaluated. This issue was identified in Regulatory Issue Summary 2000-25 dated December 26, 2000.
As stated in Mr. Jack Strosniders letter to you dated August 10, 2001, the staff found the NEI survey results on Okonite single conductor bonded-jacket cable acceptable. The survey indicated there was limited application of this cable type in nuclear power plants and the service temperatures in general were lower than the 90 degree C, the rated temperature specified by the manufacturer.
However, because of the differential transition temperatures associated with the conductor insulation and the jacket material and the bonded interface, the NRC is interested in obtaining information and additional data on the behavior of single and multiconductor bonded- jacket cables of other manufacturers.
We would appreciate receiving as much of the industrys response to these issues by October 1, 2001.
Should you have any questions regarding this matter, please contact Nilesh Chokshi at (301) 415-0190, email: ncc1@nrc.gov Sincerely,
/RA/
Michael E. Mayfield, Director Division of Engineering Technology Office of Nuclear Regulatory Research cc: N. Smith W. Horrin Distribution:
MEB r/f, A. Thadani, C. Holden, P. Shemanski, P. Kang, E. Hackett DOCUMENT NAME: G:\Vora\EQAMMEMO.wpd OAR in ADAMS? (Y or N) ADAMS ACCESSION NO.: TEMPLATE NO. RES-Publicly Available? (Y or N) DATE OF RELEASE TO PUBLIC SENSITIVE?
To receive a copy of this document, indicate in the box: "C" = Copy without enclosures "E" = Copy with enclosures "N" = No copy
- see previous concurrence OFFICE RES/DET/MEB RES/DET/MEB
- RES/DET/MEB
- NRR/DE/EEIB
- NAME S. Aggarwal /RA/ J. Vora /RA/ N. Chokshi /RA/ J. Calvo /RA/
DATE 08/22/01 08/14/01 08/14/01 08/14/01 OFFICE NRR/DRIP/RLSB
- NRR/DE
- RES/DET NAME C. Grimes /RA/ J. Strosnider /RA/ M. Mayfield /RA/
DATE 08/14/01 08/15/01 08/22/01