ML18054B509
| ML18054B509 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 03/20/1990 |
| From: | Berry K CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| REF-GTECI-A-47, REF-GTECI-SY, TASK-A-47, TASK-OR GL-89-19, TAC-74974, NUDOCS 9003270318 | |
| Download: ML18054B509 (4) | |
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consumers Power POWER I Nii MICHlliAN'S PRDliRESS General Offices:
1945 West Parnall Road, Jackson, Ml 49201 o (517) 788-1636 March 20, 1990 Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT -
RESPONSE TO GENERIC LETTER 89 REQUEST FOR ACTION Kenneth W Berry Director Nuclear licensing RELATED TO RESOLUTION OF UNRESOLVED SAFETY ISSUE A-47 (TAC NO 74974)
Generic Letter 89-19 recommends all Combustion Engineering pressurized water reactors install automatic steam generator overfill protection along with associated Technical Specifications and procedures.
In addition, Combustion Engineering plants with low-head high pressure safety injection pumps were requested to assess the adequacy of emergency procedures and operator training to ensure small-break loss-of-coolant accident capabilities encompassed the full spectrum of possible scenarios.
The Generic Letter further requested a statement as to whether or not the recommended actions of Enclosure 2, item 4a, b and c would be implemented and, if so, a schedule for the implementation.
If the recommendations are not planned to be implemented, appropriate justification is to be provided with retention of the detailed documentation on-site.
Consumers Power Company's response for Palisades Plant is provided herein.
We have evaluated the recommendations of Generic Letter 89-19, Enclosure 2, items 4a and b for automatic steam generator overfill protection, and have concluded that these recommendations should not be implemented at Palisades at this time.
The probabilistic risk assessment performed for the Reference Plant was evaluated.
Specific parts of that assessment were changed where it was anticipated that Palisades specific features might alter the results or the information used :fo the reference analysis was overly conservative.
The modified analysis results indicate the value/impact for Palisades would not be nearly as great as the value/impact for the Reference Plant.
Based on previous assessments of Palisades risks, the results of the modified analysis indic~te steam generator overfill would not be a dominant contributor to the overall risk of plant operation.
Additionally, the effects of automatic steam generator overfill protection modification need to be better understood with regard to other accident scenarios and plant responses.
The Palisades Individual Plant Evaluation (IPE) process is structured to provide a plant wide overview of these issues.
The steam generator overfill issue will be incorporated into the IPE process to obtain the best safety solutions for Palisades while avoiding unforeseen safety concerns.
OC0390-0296-NL04 A C/11/S ENERGY COMPANY
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e N~clear Regulatory Commission
.Palisades Plant Response to GL 89-19 March 20, 1990 Palisades f eedwater regulating system consists of two three-element feedwater controllers (one for each steam generator).
Steam flow, feedwater flow and steam generator downcomer level signals are received by the feedwater controllers.
The signals are processed to produce an output signal which automatically control steam generator downcomer level by positioning the associated feedwater regulating valve and varying the feedwater pump turbine driver speed.
A main turbine trip causes a feedwater regulating system override through actuation of the main steam bypass permissive switch.
This will cause the feedwater regulating valves to remain in an "as is" position and the main feedwater pump speed control to ramp feedwater pump turbine speed and discharge pressure down to a predetermined value which results in no main feedwater flow following a normal plant trip.
A high steam generator downcomer level in either generator will produce a feedwater regulating system override.
When the high level override signal is received the associated feedwater regulating valve to the affected steam generator is closed.
A steam generator high level alarm for each steam generator is provided in the control room.
2 Generic Letter 89-19, Enclosure 2, item 4b recommends plant procedures and Technical Specifications include provisions to verify operability of the overfill protection system.
As previously discussed, probabilistic risk assessment analysis indicates the existing main feedwater regulating system, overrides and feedwater system design provides adequate overfill protection.
Existing plant Technical Specifications do not provide operability and testing requirements for this equipment.
Our efforts with Restructured Technical Specifications (RTS) indicate inclusion of this equipment within RTS would not be consistent with the established criteria of the RTS program.
- However, operability functional checks, calibration, and testing of this equipment is performed unde~ our self-initiated Augmented Testing Program.
The Augmented Testing Program was established to ensure activities satisfying specified regulatory commitments are performed at their prescribed frequency.
Initial activities were generated as action items from our 1987 System Functional Evaluation.
The NRC has been previously informed of the System Functional Evaluation Program through correspondence dated July 3, 1986, December 1, 1986, January 28, 1987 September 14, 1987 and October 30, 1987.
Under the Augmented Testing Program, the following elements for the existing main feedwater regulating system are verified on a routine basis:
- 1.
Steam generator high level override to the main feedwater regulating valve testing.
- 2.
Calibration and testing of feedwater regulating controls, instruments, interlocks and alarms.
- 3.
Calibration and testing of feedwater regulation interface to the feedwater pump speed controllers.
OC0390-0296-NL04
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e N~clear Regulatory Commission Palisades Plant Response to GL 89-19 March 20, 1990
- 4.
Calibration and testing of feedwater pump speed control instruments.
- 5.
Feedwater Regulating Valve Preventative Maintenance.
The recommendation of Generic Letter 89-19, Enclosure 2, item 4c has been implemented.
A reassessment of Palisades licensing design basis, emergency procedures and operator training programs has been performed.
Adequate procedures exist to address the full spectrum of possible small-break loss-of-coolant accident scenarios.
Primary system depressurization, reference temperature nil ductility transition limits, and failure of components impacting the ability to achieve safe shutdown have been factored into the success paths established within the procedures. As requested by the Generic Letter, documentation of this assessment is available on-site.
Conclusions are the operator training programs and procedures provide the operator sufficient knowledge and capability to respond to small-break loss-of-coolant accidents.
Kenneth W Berry Director, Nuclear Licensing cc:
Administrator, Region III, NRC NRC Resident Inspector, NRC OC0390-0296-NL04 3
CONSUMERS POWER COMPANY Palisades Plant Docket 50-255 License DPR-20 Response to Generic Letter No 89-19 At the request of the Commission and pursuant to the Atomic Energy Act of 1954 and the Energy Reorganization Act of 1974, as amended, and the Commission's Rules and Regulations thereunder, Consumers Power Company submits our response to NRC Generic Letter 89-19 dated September 20, 1989, entitled, "Request for Action Related to Resolution of Unresolved Safety Issue A-47".
Consumers Power Company's response is dated March 20, 1990.
CONSUMERS POWER COMPANY To the best of my knowledge, information and belief, the contents of this submittal are truthful and complete.
By~~
David e
Nuclear Operations Sworn and subscribed to before me this 20th day of March 1990.
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Elaine E Buehrer, Notary Public Jackson County, Michigan My commission expires October 11, 1993 OC0390-0296-NL04