ML052450444

California Independent System Operator (Caiso) Communications with Pacific Gas & Electric Company During the Power Line Outage on August 25, 2005

ML052450444
Person / Time
Site:	Diablo Canyon
Issue date:	09/02/2005
From:	Marsh L NRC/NRR/DLPM/LPD4
To:	Oatley D Pacific Gas & Electric Co
SHUKLA G , NRR/DLPM/PD4, 415-8420
References
Download: ML052450444 (5)

Text

September 2, 2005 Mr. David H. Oatley, Vice President and General Manager Diablo Canyon Power Plant P.O. Box 56 Avila Beach, CA 93424

SUBJECT:

CALIFORNIA INDEPENDENT SYSTEM OPERATOR (CAISO)

COMMUNICATIONS WITH PACIFIC GAS & ELECTRIC COMPANY DURING THE POWER LINE OUTAGE ON AUGUST 25, 2005

Dear Mr. Oatley:

On August 25, 2005, a loss of a major western transmission line occurred just as California power use was approaching its peak. This forced the California Independent System Operator (CAISO) to issue a Transmission Emergency Notice for Southern California and to request utilities in the Southern Region to reduce demand on the system by dropping 900 megawatts of firm load and 800 megawatts of voluntary, interruptible customers. The Nuclear Regulatory Commission staff is concerned that these conditions may have challenged the operability of the offsite power for Diablo Canyon Power Plant, Unit Nos. 1 and 2 (DCPP). While the problem was adequately resolved by the end of the day, we would appreciate your assessment of your communications with the CAISO as it relates to grid conditions and reliable offsite power for DCPP.

We are making continued efforts to ensure appropriate communication between nuclear power plant operators and grid operators. The issuance of Temporary Instruction 2515/163, Operational Readiness of Offsite Power, is a recent effort to take a snapshot of relevant operational readiness at nuclear power plants. Any information that addresses the following questions would enable us to better understand the effectiveness of your efforts in this area.

1. Did the CAISO issue any warnings on the abnormal conditions for August 25, 2005? If there were any warnings, what were those warnings and when were they issued?

2. What type of warnings were directly communicated to DCPP?

3. Was there any communication with DCPP from the transmission system operator (TSO)/CAISO before or after load shedding was ordered on the grid?

4. Did the communication with the grid operators/CAISO meet your expectations?

5. Recognizing the significance of the grid transient, what is your assessment regarding the adequacy of the interaction with the TSO/CAISO that you experienced during this event?

D. Oatley We would appreciate your comments by September 30, 2005. If you have any questions regarding the information in this letter, please contact Mr. Girija Shukla at 301-415-8439.

Sincerely, Ledyard B. Marsh, Director /RA/

Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-275 and 50-323 cc: See next page

D. Oatley We would appreciate your comments by September 30, 2005. If you have any questions regarding the information in this letter, please contact Mr. Girija Shukla at 301-415-8439.

Sincerely, Ledyard B. Marsh, Director /RA/

Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-275 and 50-323 cc: See next page DISTRIBUTION:

PUBLIC PDIV-2 Reading RidsNrrDlpmPdiv (HBerkow)

RidsNrrPMGShukla RidsNrrLALFeizollahi RidsNrrDlpmPdiv2 (DCollins)

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RidsOgcRp TKoshy RJenkins JCalvo RidsNRRDE ACCESSION NO.: ML052450444 NRR-106 OFFICE PDIV-2/PM PDIV-2/LA PDIV/PD DLPM/D NAME GShukla LFeizollahi HBerkow LMarsh DATE 9/2/05 9/2/05 9/2/05 9/2/05 OFFICIAL RECORD COPY

Diablo Canyon Power Plant, Units 1 and 2 cc:

NRC Resident Inspector Richard F. Locke, Esq.

Diablo Canyon Power Plant Pacific Gas & Electric Company c/o U.S. Nuclear Regulatory Commission P.O. Box 7442 P.O. Box 369 San Francisco, CA 94120 Avila Beach, CA 93424 Mr. David H. Oatley, Vice President Sierra Club San Lucia Chapter and General Manager c/o Henriette Groot Diablo Canyon Power Plant 1000 Montecito Road P.O. Box 56 Cayucos, CA 93430 Avila Beach, CA 93424 Ms. Nancy Culver City Editor San Luis Obispo The Tribune Mothers for Peace 3825 South Higuera Street P.O. Box 164 P.O. Box 112 Pismo Beach, CA 93448 San Luis Obispo, CA 93406-0112 Chairman Mr. Ed Bailey, Chief San Luis Obispo County Board of Radiologic Health Branch Supervisors State Department of Health Services Room 370 P.O. Box 997414 (MS 7610)

County Government Center Sacramento, CA 95899-7414 San Luis Obispo, CA 93408 Mr. James D. Boyd, Commissioner Mr. Truman Burns California Energy Commission Mr. Robert Kinosian 1516 Ninth Street (MS 31)

California Public Utilities Commission Sacramento, CA 95814 505 Van Ness, Room 4102 San Francisco, CA 94102 Mr. James R. Becker, Vice President Diablo Canyon Operations Diablo Canyon Independent Safety and Station Director Committee Diablo Canyon Power Plant ATTN: Robert R. Wellington, Esq. P.O. Box 3 Legal Counsel Avila Beach, CA 93424 857 Cass Street, Suite D Monterey, CA 93940 Jennifer Tang Field Representative Regional Administrator, Region IV United States Senator Barbara Boxer U.S. Nuclear Regulatory Commission 1700 Montgomery Street, Suite 240 Harris Tower & Pavillion San Francisco, CA 94111 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064 March 2005