ML20012C996

Responds to Generic Ltr 89-19 Re USI A-47, Safety Implication of Control Sys in LWR Nuclear Power Plants. Mod Request MR-FC-084 Initiated to Provide Automatic Steam Generator Overfill Protection

ML20012C996
Person / Time
Site:	Fort Calhoun
Issue date:	03/19/1990
From:	Gates W OMAHA PUBLIC POWER DISTRICT
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-GTECI-A-47, REF-GTECI-SY, TASK-A-47, TASK-OR GL-89-19, LIC-90-0205, LIC-90-205, NUDOCS 9003260267
Download: ML20012C996 (4)

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Omaha Public Power District 1623 Harney Omaha, Nebraska 68102 2247 402/536-4000 March 19, 1990 LIC-90-0205 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Station P1-137 Washington, DC 20555

References:

1. Docket No. 50-285

2. Letter from NRC (J. G. Partlow) dated September 20, 1989 (Generic Letter 89-19)

Gentlemen:

SUBJECT:

Response to Generic Letter 89 19 Regarding Unresolved Safety Issue A-47 " Safety Implication of Control Systems in LWR Nilclear l Power Plants" Reference 2 requested licensees to provide a statement to indicate whether the ,

recommendations of Generic Letter 89-19 Enclosure 2 will be implemented, and if f so, to provide a' schedule and basis for the schedule. Omaha Public Power .'

District's (OPPD) response to Reference 2 is attached.

"This response is being submitted under oath in accordance with the reporting recuirements of Generic Letter 89-19. If you have questions or require adcitional information, please contact me.

Sincerely,

p. .Z. Acom, W. G. Gates l Division Manager l Nuclear Operations

WGG/pje Attachment c: LeBoeuf, Lamb, Leiby & MacRae A. Bournia, NRC Project Manager R. D. Martin, NRC Regional Administrator, Region IV g P. H. Harrell, NRC Senior Resident Inspector 'g0\

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4 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION In the Matter of Omaha Public Power District ) Docket No. 50-285 (Fort Calhoun Station )

Unit No. 1) )

AFFIDAVIT W. G. Gates, being duly sworn, hereby deposes and says that he is the Division r Manager - Nuclear Operations of the Omaha Public Power District; that as such he is duly authorized to sign and file with the Nuclear Regulatory Commission the attached information concerning the response to NRC Generic Letter 89-19; that he is familiar with the content thereof; and that the matters set forth therein are true and correct to the best of his knowledge, information, and belief.

M. 5.

W. G. Gates Division Manager Nuclear Operations

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STATE OF NEBRASKA) maustensleene i ss L PATRMM COUNTY OF DOUGLAS N 8 * " I' "

l Subscribed and sworn,.t*o before me, a Notary Public in and for the State of l Nebraska on this N day of March, 1990.

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Generic letter 89-19 Enclosure 2. Item (4)(al It is recommended that all Combustion Engineering plants provide automatic, steam generator overfill protection to mitigate main feedwater (MFW) overfeed events. The design for the overfill-protection system should be sufficiently separate from the MFW control system to ensure that the MFW pump will trip on a steam generator high-water-level signal when required, even if a loss of power, a loss of ventilation, or a fire in the control portion of the MFW control system should occur. Common failure modes that could disable overfill protection and the feedwater control system, but would still result in a feedwater pump trip, are considered acceptable failure modes.

OPPD Respons_q A modification request (MR-FC 89-084) has been initiated with regard to providing automatic steam generator overfill protection. This modification is tentatively scheduled for completion by the end of the 1991 refueling outage.

Generic letter 89-19 Enclosure 2. Item (4)(b)

It is recommended that plant procedures and technical specifications for all Combustion Engineering plants include provisions to verify periodically the operability of overfill protection and ensure that automatic MFW overfill protection is operable during reactor power operation. The instrumentation should be dmonstrated to be operable by the performance of a channel check, channel functional testing, and channel calibration, including setpoint verification, and by identifying the LCOs. These technical specifications should be comensurate with existing plant technical specifications requirements for channels that initiate protection actions.  ;

OPPD Resoonse Periodic verification and testing of the feedwater regulating system is currently satisfied, utilizing calibration procedures CP-1101-1 and CP-1102-1.

Those procedures are scheduled on a refueling outage basis to ensure both high/ low setpoints are within calibration limits, and that the associated feedwater regulating circuitry initiates valve rampdown per design. Procedures for periodic verification and testing of the overfill protection system will be implemented upon completion of the planned modification. Also, during the preparation of the overfill protection modification, OPPD will consider the need for technical specification changes and submit such changes, if appropriate.

Generic letter 89-19 Enclosure 2. Item (4)(c) l It is recommended that all utilities that have plants designed with high-pressure-injection pump-discharge pressures less than or equal to 1275 psi reassess their emergency procedures and operator training programs and modify them, as needed, to ensure that the operators can handle the full spectrum of possible small-break loss-of-coolant accident (SBLOCA) scenarios. This may include the need to depressurize the primary system via the atmospheric dump valves or the turbine bypass valves and cool down the plant during some SBLOCA. The reassessment should ensure that a single failure would not negate the operability of the valves needed to achieve safe shutdown.

The procedure should clearly describe any actions the operator is required to  :

perform in the event a loss of instrument air, or electric power prevents remote operation of the valves. The use of the pressurizer PORVs to depressurize the plant during an SBLOCA, if needed, and the means to ensure that the R1 41DT (reference temperature, nil ductility transition) limits are not compromised should also be clearly described. Seven plants have been

! identified that have high pressure injection pump discharge pressures less than ,

L or equal to 1275 psi that may require manual pressure-relief capabilities using the valves to achieve safe shutdown. They are: Calvert Cliffs 1 and 2, Fort  ;

Calhoun, Millstone 2, Palisades, and St. Lucie 1 and 2. ,

OPPD Response OPPD has reviewed both the current Emergency Operating Procedures and the simulator training program. The procedures and training address the need to cool down the plant via atmospheric dump valves. The valves necessary to cool down the plant via the steam generators are single failure proof and described ,

in the procedures. The functional recovery procedures and training program >

address the need to depressurize the Reactor Coolant System under small break loss of coolant accident conditions with insufficient break flow and inadequate heat removal via the steam generators. The procedures address the use of PORV's to depressurize the plant and means to assure the RT NDT limits are not +

compromised. In order to ensure proper local operation of manual valves, two training revision requests were initiated. These lesson plan revisions will be in place by June 30, 1990. Future changes to procedures and/or training will be initiated as necessary to address the planned modification identified in item (4)(a).

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