IR 05000528/1996010
| ML17312A924 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 08/19/1996 |
| From: | Callan L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Stewart W ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| Shared Package | |
| ML17312A925 | List: |
| References | |
| EA-96-203, NUDOCS 9608230054 | |
| Download: ML17312A924 (6) | |
Text
SUBJECT:
NOTICE OF VIOLATION (NRC Inspection Repor t No. 50-528/96-10; 50-529/96-10:
50-530/96-10)
Dear Hr. Stewart:
This is in reference to the predecisional enforcement conference conducted on August l. 1996.
in the NRC's Region IV office, Arlington. Texas.
The conference was conducted to discuss apparent violations discovered following electrical fires that occurred at the Palo Verde Nuclear Generating Station (Palo Verde). Unit 1.
on April 4.
1996.
The apparent violations included:
1)
a fai lure to properly ground a regulating transformer by not assuring the electrical system was built in accordance with plant design documents:
and 2)
a failure to assure compliance with the NRC fire protection requi rements in 10 CFR Part 50. Appendix R by not assuring protection of both trains of safe-shutdown equipment.
The apparent violations were described in an inspection report issued on July ll. 1996.
Arizona Public Service Company (APS)
described the April 4 fires in Licensee Event Report 96-01 issued on Hay 6.
1996.
and Revision 1 issued on June ll. 1996.
As noted in the NRC's inspection report.
Palo Verde operations personnel responded appropriately to the April 4 electrical fires. which were caused by the grounding problem.
The fires were promptly detected and extinguished and posed no safety threat to the facility. which was shut down at the time.
The NRC's concern was that the fires occurred simultaneously in electrical panels in the control room and the "8" DC equipment room.
rooms containing components associated with both trains of the equipment relied upon to achieve a safe shutdown condition in the event of a fire.
Appendix R requires that at least one train of safe-shutdown equipment be protected against -fire damage.
At the conference.
Arizona Public Service Company (APS) representatives agreed that a fai lure to comply with electrical grounding design requirements of IEEE 142.
as committed to in the Palo Verde Final Safety Analysis Report.
had occurred during plant construction.
and that this constituted a violation of
CFR Part 50. Appendix B. Criterion III. but disagreed with the NRC's contention that APS had violated NRC's fire protection requirements.
APS's conference presentation.
which summarized its position on the apparent violations.
was placed in the NRC's Public Document Room on August 12, 1996
'ia a predecisional enforcement conference summary.
In brief. APS's basis for disagreeing with the apparent Appendix R violation was that the electrical circuits involved in causing the April 4 electrical
e
)
Arizona Public Service Co.
-2-fires are not within the scope of the Appendix R fire protection requirements.
APS's position expressed at the conference is that Appendix R requires fire protection and electrical isolation of the actual safe shutdown circuits and their associated circuits.
Furthermore, APS stated that there was no real potential for a fire caused by the specific electrical grounding problem to have affected both trains of safe shutdown ci rcuits in the control room and the alternate shutdown train, which is outside the control room at Palo Verde.
because of the plant's comprehensive.
defense-in-depth fire protection program.
Based on our consideration of the information developed during the inspection and the information that you provided during the conference, the NRC has determined that the most appropriate disposition of this matter is to issue a
citation for a design control fai lure, i.e.. the electrical grounding problem that caused the fires.
The NRC is not issuing a citation against the requirements of Appendix R because these fires resulted from an electrical design error and did not result from weaknesses in the development and implementation of the Palo Verde fire protection program.
Thus.
the violation described in the enclosed Notice of Violation involves a failure to meet the requirements of 10 CFR Part 50, Appendix B. Criterion III, Design Control.
The NRC considers this electrical design error important because it created a
fire vulnerability in two areas of the plant and could have resulted in operational challenges which are outside of the plant's design basis.
Since these electrical system design errors are outside the scope of Appendix R, the NRC is concerned that this type of fire. depending on plant configuration.
may alter the predicted ef'feet of fires on reactor safety.
However. the NRC acknowledges the points APS made at the conference with regard to Palo Verde's defense-in-depth fire protection program and other fire protection features.
and the ability to mitigate the potential for this type of fire.
In light of these considerations and the fact that the April 4 fire had no actual impact on safe shutdown equipment or its capability. the NRC has classified this violation at Severity Level IV in accordance with the "General Statement of Policy and Procedure for NRC Enforcement Actions" (Enforcement Policy).
The NRC has concluded that information regarding the reason for the violation.
the corrective actions taken and planned to correct the violation and prevent recurrence is already adequately addressed on the docket in LER 96-01.
and Revision 1 to this LER, issued Hay 6 and June 11.
1996, respectively.
Therefore'ou are not required to respond in accordance with the provisions of 10 CFR 2.201 unless the description in the referenced documents does not accurately reflect your corrective actions or your position.
In that case.
or if you choose to provide additional information. you should follow the instructions specified in the enclosed Notice.
In accordance with 10 CFR 2.790 of the NRC's "Rules of Practice."
a copy of this letter. its enclosures and your response if you choose to provide one.
will be placed in the NRC Public Document Room (PDR).
To the extent possible.
Arizona Public Service Co.
-3-any response you choose to provide should not include any personal privacy.
proprietary.
or safeguards information so that it can be placed in the PDR without redaction.
Sincerely
.
Docket Nos. 50-528:
50-529:
50-530 License Nos.
NPF-41:
NPF-51:
NPF-74 Enclosure:
. Callan Regional Administrator cc w/Enclosure:
Mr. Steve Olea Arizona Corporation Commission 1200 W. Washington Street Phoenix.
Arizona 85007 Douglas K. Porter.
Senior Counsel Southern Ca 1 i forni a Edi son Company Law Department.
Generation Resources P.O.
Box 800 Rosemead.
Cali forni a 91770 Aubrey V. Godwin. Director Arizona Radiation Regulatory Agency 4814 South 40 Street Phoenix, Arizona 85040 Chairman Maricopa County Board of Supervisors 111 South Third Avenue Phoenix.
Arizona 85003 Angela K. Krainik. Manager Nuclear Licensing Arizona Public Service Company P.O.
Box 52034 Phoenix.
Arizona 85072-2034 John C. Horne.
Vice Presi dent Power Supply Palo Verde Services 2025 N. Third Street.
Suite 220 Phoenix, Arizona 85004 Mr. Roy P.
Lessy. Jr.
Akin. Gump, Strauss.
Hauer II Feld.
L.L.P 1333 New Hampshire Avenue.
N.W.
Suite 400 Washington.
D.C.
20036
E