ML20217P070
| ML20217P070 | |
| Person / Time | |
|---|---|
| Issue date: | 04/08/1998 |
| From: | Calvo J NRC (Affiliation Not Assigned) |
| To: | Jessie Delgado WISCONSIN ELECTRIC POWER CO. |
| References | |
| NUDOCS 9804090307 | |
| Download: ML20217P070 (3) | |
Text
b April B,'1998 F
Mr. Josd M. Delgado ^
Assistant Vice PresidInt >
M-hy
). #
- Elictric Systems Operati:ns Wisconsin Electric Milwaukee, WI 53201
Dear Mr.- Delgado:
I received a copy of the final report of the Secretary of Energy Advisory Board (SEAB) Task Force on Electric System Reliability entitled, "The Characteristics of the independent System Operator," that was written under your leadership. On March 25,1997, during the L second meeting of the SEAB Task Force I had the opportunity to speak with you and other l members'of the Task Force regarding the special concerns of the Nuclear Regulatory l Commission (NRC) on bulk power system' reliability or grid reliability. _Our staff began l efforts in January of 1997, to better understand the complexities of electric industry i" deregulation and its potential impact on grid. reliability and the availability of offsite power to nuclear power plants in order to inform and advise NRC senior management. We have i i consulted with the cognizant representatives of Department of Energy, Federal Energy j l- Regulatory Commission, North American Electric Reliability Council, Nuclear Energy institute
! l and individual electric utilities on these issues. In the spirit of the open exchange of ideas .
and information which we have had with many of the stakeholders in this area we would
, like to share our comments on the subject SEAB Task Force report.
I As you read our enclosed comments I would urge you and other members of the SEAB Task -!
Force to carefully consider both the unique regulatory constraints and the strategic energy
- resource associated with the operation of nuclear power plants. We offer for your
- consideration recommendations regarding the role'and responsibilities of the ISO with l respect to nuclear power plants which we feel are necessary to assura reliable grid operation. Nuclear power plants have specific and unique design and safe operational
' requirements that both the ISO 'and regional reliability coordinator must be aware of and act in a manner to ensure that the grid meets needed reliability requirements. If you have any questions on this matter please feel free to contact me or Ronaldo Jenkins of my staff at' (301) 415-2985. '
- Sincerely, l
l _ !$$ :
Josd A. Calvo, Chief l Electrical Engineering Branch i Division of Engineering l .j] Office of Nuclear Reactor Regulation
- Ecclosure:
L Comments Provided to the Secretary of Energy Advisory Board ~
L cc: Dr. Philip R. Sharp, Chairman SEAB Task Force g~9J Brendan Kirby, P. E., Oak Ridge National Laboratory Gus A' Lainas, Nuclear Regulatory Commission
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OFFICE EELB:DE:NRR ' E SC/EELB:DE:NRR SECY/EELB:DE:NRR C/EELB:DE:NRR 6 l NAME- RJenkins:ahe PGill /k JACalvo M DATE- 04/8/98 04///98 04/ /98 04/f/98 I 9904090307 980408 OFFICIAL RECORD COPY ,
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COMMENTS PROVIDED TO THE SECRETARY OF ENERGY ADVISORY BOARD TASK FORCE ON ELECTRIC SYSTEM RELIABILITY DIRECTED TO THE ROLES AND RESPON.Sl81LITIES OF THE INDEPENDENT SYSTEM OPERATOR WITH RESPECT TO NUCLEAR POWER PLANT OPERATION
' INTRODUCTION We applaud the Task Force's efforts and the recommendations concerning the need for independent System Operators (ISOs), regional security coordinators, and a Self Regulating Reliability Organization (SRRO) that address reliability requirements. Our primary concern is in assuring the adequacy and reliability of the offsite power supply to nuclear power plants.
Safe nuclear plant emergency shutdown requires a source of power capable of maintaining acceptable static and dynamic voltage and frequency levels while supplying varying amounts of both real and reactive power. The preferred source of such safe shutdown power is the offsite electric power system, or regional grid. Since accident sequences initiated by loss of offsite power are important contributors to risk for most plants, the reliability of the offsite electric transmission network is important to nuclear power plant safety.
= Historically, nuclear plant owners have also frequently been the operators of the host control area and had full responsibility and authority over activities that could impact transmission reliability. This has provided a natural connection between the nuclear plants' offsite power requirements and the transmission system activities necessary to assure the reliability of that supply.
Many features of the ISO concept are attractive and may increase the security of nuclear plant offsite power supply. The large geographic scope the Task Force has recommended,
< especially when coupled with even broader geographic oversight by regional reliability coordinators, will reduce the vulnerability of offsite power supply degradation that might result from system disturbances or commercial transactions occurring outside the geographic boundary of the traditional control area operator.
We are concerned, however, that mechanisms must be in place to assure that the ISOs and regional reliability coordinators are aware of the unique power supply requirements of each nuclear plant. Continued operation of the nuclear plants necessitates that !hese requirements be formally integrated into the operations and planning of the ISOs and regional reliability coordinators.
We recommend that the Task Force acknowlet;s the importance of assuring the reliability and adequacy of the offsite power supply to auclear plants that nuclear plants often have unique reliability requirements concerning ine supply of offsite power, and that these requirements must be addressed by ISOs, regional reliability coordinators, and the SRRO.
While nothing in the Task Force report precludes this, we feel that it is important that it be explicitly stated.
ENCLOSURE
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BACKGROUND
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In 1996, two electrical grid disturbances on the Western Grid, one in July and a second more severe event in August, caused numerous plants to trip, including several nuclear units. Although no nuclear plant lost all offsite power, such events do have the potential to increase the dependance on the backup onsite power system and to challenge plant safety systems more than originally intended when the plant was licensed.
The impending deregulation of the electric power industry may impact grid reliability and thus, in turn affect the availability of offsite power to nuclear power plants. Safe nuclear plant operation requires a source of power capable of maintaining voltage and frequency within acceptable limits uniquely defined for each nuclear plant. The preferred power source for safe plant operation is the offsite electric power system, or grid.
Information gathered from NRC staff visits to many of the Nation's load dispatch centers indicates considerable variability in terms of capabilities and regional vulnerabilities to transient conditions. Overall, we note that it is an exceptional nuclear power plant configuration which is not interdependent with other generating plants in order to maintain its voltage requirements.
A nuclear plant may develop detailed protocols with their local ISO. However, if that '
nuclear plant is located near the boundary between two or more ISOs then a broader recognition of nuclear plant operating criteria must be established. A regional reliability-coordinator who can provide control over several ISOs must be in place to ensure reliability of the grid for nuclear plants. A case study of NERC disturbance No.10 in 1997, shows ;
how important this concept can become. This disturbance came very close to resulting in three regions of NERC separating and going into independent Islanded operation on June 11,1997. Had this event evolved fully it might have resulted in a large scale blackout that could have impacted potentisily some 12 nuclear plants in 7 states.
CAllFORNIA ISO The following key aspects of the relationships between the California ISO and resident nuclear power plants are reflected in their ISO Tariff and Transmission Control Agreement:
Recognition of nuclear plant operating criteria established under NRC licenses.
Priority to restoring cffsite power to nuclear power plants as specified under design-basis and licensing requirements.
( Promulgation and maintenance of ISO operating procedures to maintain voltage and frequency requirements at nuclear power plants.
.We consider the California ISO arrangements with respect to its support of the safety requirements for the state's nuclear power plants to be an appropriate model going forward under deregulation. We recommend that any future ISO arrangement support the integrated planning and implementation of energy dispatch schemes which maintain the design-basis requirements for the offsite power (i.e., highly reliable) for all nuclear power plants.
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