ML17312B683
| ML17312B683 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 09/11/1997 |
| From: | Thomas K NRC (Affiliation Not Assigned) |
| To: | James M. Levine ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| Shared Package | |
| ML17312B684 | List: |
| References | |
| GL-92-08, GL-92-8, TAC-M85583, TAC-M85584, TAC-M85585, NUDOCS 9709260051 | |
| Download: ML17312B683 (7) | |
Text
September 11, 1997 Hr. James H. Levine Executive Vice President, Nuclear Arizona Public Service Company Post Office Box 53999 Phoeni x, Arizona 85072-3999
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION REGARDING GENERIC LETTER 92-08.
"THERMO-LAG 330-1 FIRE BARRIERS" FOR THE PALO 'VERDE NUCLEAR GENERATING STATION (TAC NOS.
- H85583, M85584 AND H85585)
Dear Mr. Levine:
By letter dated January 24, 1997, Arizona Public Service Company submitted a
response to the NRC Request for Additional Information (RAI) dated November 3, 1995, related to Generic Letter (GL) 92-08, "Thermo-Lag 330-1 Fire Barriers,"
for Palo Verde Nuclear Generating Station (PVNGS), Units 1, 2 and 3.
The staff, in conjunction with its contractor, Sandia National Laboratories (SNL),
has reviewed the January 24,
- 1997, response and has determined that the additional information discussed in the enclosure is needed to complete the review of the ampacity der ating factor determinations.
To assist the staff in completing its review of the.application of Thermo-Lag 330-1 Fire Barriers at PVNGS, please respond in writing to this request for additional information within 30 days from the date of this letter.
If you have any questions, please contact me at (301) 415-1362.
Docket Nos.
STN 50-528, STN 50-529 and STN 50-530
Enclosure:
Request for Additional Information cc w/encl:
See next page Sincerely, Original Signed By Kristine M. Thomas, Project Manager
, Project Directorate IV-2 Division of Reactor Projects
- III/IV Office of Nuclear Reactor Regulation DISTRIBUTION:
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Hr. James H. Levine September 11, 1997 cc w/encl:.
Hr. Steve Olea Arizona Corporation Commission 1200 W. Washington Street Phoenix, Arizona 85007 Douglas Kent Porter Senior Counsel Southern California Edison Company Law Department.
Generation Resources P.O.
Box 800 Rosemead; California 91770 Senior Resident Inspector USNRC P. 0.
Box 40 Buckeye, Arizona 85326 Regional Administrator, Region IV U. S. Nuclear Regulatory Commission Harris Tower 8 Payi llion 611 Ryan Plaza Drive. Suite 400 Arlington, Texas 76011-8064 Chairman.
Board of Supervisors ATTN:
Chairman 301 W. Jefferson.
10th Floor Phoenix, Arizona 85003 Mr. Aubrey V. Godwin. Director Arizona Radiation Regulatory Agency 4814 South 40 Street
- Phoenix, Arizona 85040 Hs. Angela K. Krainik, Manager Nuclear Licensing Arizona Public Service Company P.OS Box 52034 Phoenix. Arizona 85072-2034 Hr. John C. Horne.
Vice President Power Supply Palo Verde Services 2025 N. Third Street.
Suite 220
- Phoenix, Arizona 85004 Hr. Robert Burt Los Angeles Department of Water 8 Power Southern California Public Power Authority ill North Hope Street, Room 1255-B Los Angeles. California 90051 Mr. David Summers Public Service Company of New Mexico 414 Silver SW. f0604 Albuquerque.
New Mexico 87102 Mr. Robert D. Bledsoe Southern California Edison Company 14300 Mesa
- Road, Drop D41-SONGS San Clemente, California 92672 Mr. Robert Henry Salt River Project 6504 East Thomas Road Scottsdale.
Arizona 85251 Terry
.Bassham, Esq.
General Counsel El Paso Electric Company 123 W. Mills El Paso.
Texas 79901
Encl osure RE UEST FOR ADDITIONAL INFORMATION PALO VERDE NUCLEAR GENERATING STATION UNITS 1 2 AND 3 FIRE BARRIER AMPACITY DERATING ISSUES Sandia National Laboratories (SNL) found after a review of the licensee's cable ampacity assessment methodology (i.e..
Leake Methodology) which is based on permitting some credit for the diversity of power cable loads as described in an IEEE Transactions paper by H. C.
Leake entitled "Sizing Cables in Randomly-Filled Tray With Consideration for Load Diversity." that the licensee did not establish a basis for deciding when the subject method is appropriate or did not have sufficient checks to ensure that unrealistic results are not credited via the analysis.
5NL recommended that the following set of limitations
.be established to resolve any potential misapplications or concerns regarding the use of the subject methodology:
~
It is recommended that in the application of the Leake method to diverse random fill cable trays. the maximum baseline capacity limit, or maximum baseline heat intensity, should under no circumstance be assumed to exceed 80K of the corresponding open air limits.
That is, any calculation that estimates a baseline ampacity limit (or equivalently the corresponding heat intensity level) that exceeds 80K of the cable's open air ampacity should be discounted and disregarded.
~
The Leake method f'r crediting diversity should not be applied to the analysis of any cable whose diameter is greater than or equal to one half the tray fill depth as calculated using the ICEA definitions of cable cross-section and fill depth.
~
The Leake method should not be applied to any cable tray with a diversity of 50K or more where. in this case, diversity is defined as the. ratio of the cross-sectional area of cables which are assumed to carry continuous loads to the total cable mass cross-
- section.
The licensee is requested to consider the incorporation of the proposed recommendations by SNL into the application of the subject methodology or alternatively, to address the applicable concerns and criticisms as identified in the attached SNL report and to provide any direct test results which validates the Leake methodology.
SNL noted several discrepancies in both the maintained spacing and diversity based examples provided in the licensee submittal dated January 24.
1997.
J I'
Specifically, the following discrepancy was noted for the maintained spacing analysis:
~
The licensee should ensure that for the analysis of maintained spacing installed cables, the ampacity correction factors from Table YII of the IPCEA P-46-426 standard are being applied as appropriate to each case example.
It would appear from the cited example that these factors have not been included in the assessment.
The following discrepancies were noted for the maintained spacing analysis:
~
SNL was unable to reproduce to licensee's cited numerical results.
In particular, SNL's calculations estimated a baseline amnacity limit lower than that cited by the licensee even though the same methodology was applied.
It is recommended that the licensee resolve the apparent discrepancy regarding the cited diversity case example analysis, and to ensure that no similar discrepancies have been introduced into the other in-plant applications of the methodology.
~
SNL's re-analysis of the example case indicated that the specific cable under study did not have sufficient margin to allow for estimated fire barrier derating impact.
It is recommended that in resolving the numerical results discrepancy described immediately above.
the licensee provide a resolution of the apparently overloaded cable in the cited example tray.
The licensee is requested to resolve the subject discrepancies and ensure that applicable licensee calculations are revised as necessary.
Attachment:
Letter Report by Sandia National Laboratories