ML17304B099
| ML17304B099 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 04/05/1989 |
| From: | Chan T Office of Nuclear Reactor Regulation |
| To: | Karner D ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| References | |
| TAC-59124, TAC-62798, TAC-67168, NUDOCS 8904180050 | |
| Download: ML17304B099 (13) | |
Text
April 5, 1989 Docket No.:
STN 50-528, STN 50-529 Nr. Donald B. Karner Executive Vice President Arizona Nuclear Power Project Post Office Box 52034 Phoenix, Arizona 85072-2034
Dear Nr. Karner:
AND STH-530 DISTRIBUTION
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LPDRs PD5 Reading HVirgilio JLee TLChan NDavis EJordan BGrimes
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION - 10 CFR 50.62 (ATWS RULE)
- 62798, 67168)
The ATWS Rule (10 CFR 50.62, "Requirements for Reduction of Risk from Anticipated Transients Without Scram (ATWS) Events f'r Light-Water-Cooled Nuclear Power Plants" ) requires improvements in the design and operation of commercial nuclear power facilities to reduce the likelihood of failure to shutdown the reactor following anticipated transients, and to mitigate the consequences of an ATWS event.
The requirements for Combustion Engineering plants such as Palo Verde are to provide a diverse scram system (DSS),
diverse auxiliary feedwater system (AFWS) actuation, and diverse initiation of turbine trip.
Paragraph (c) (6) of the rule requires that information sufficient to demonstrate compliance with the requirements be submitted to the NRC.
He have reviewed Combustion Engineering letters dated February 27 and September 18, 1987 which described the System 80 plant's compliance with the ATWS Rule.
We find that the information provided is not sufficient to determine compliance with the Commission's regulations.
Therefore, we ask that the in-formation requested by the Enclosure be provided within 30 days from receipt of this letter, or provide an alternate schedule for doing so within 15 days.
The reporting and/or recordkeeping requirements of this letter affect fewer than ten respondents; therefore, Ol1B clearance is not required under P.L.96-511.
S incere ly,
Enclosure:
As stated Terence L. Chan, Senior Project Manager Project Directorate Y
Division of Reactor Projects III, IV, V and Special Projects Office of Nuclear Reactor Regulation cc: +e DRSP/PD5 TChan:cd 04/5 /89 next, page DRSP D:PD5 GWKn~hton 04/5 /89 oW/
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n +p*y4 UNITEDSTATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 April 5, 1989 Docket No.:
STN 50-528, STN 50-529 AND STN-530 ter. Donald B. Karner Executive Vice President Arizona Nuclear Power Project Post Office Box 52034 Phoenix, Arizona 85072-2034
Dear Nr. Karner:
SUBJECT:
RE(VEST FOR ADDITIONAL INFORMATION - 10 CFR 50.62 (ATWS RULE)
- 62798, 6?168)
The ATWS Rule (10 CFR 50.62, "Requirements for Reduction of Risk from Anticipated Transients Without Scram (ATWS) Events for Light-Water-Cooled Nuclear. Power Plants" ) requires improvements in the design and operation of commercial nuclear power facilities "to reduce the likelihood of failure to shutdown the reactor following anticipated transients, and to mitigate the consequences of an ATWS.event.
The requirements for Combustion Engineering plants such as Palo Verde are to provide a diverse scram system (DSS),
diverse auxiliary feedwater system (AFWS) actuation, and diverse initiation of turbine trip.
Paragraph (c) (6) of the rule requires that information sufficient to demonstrate compliance with the requirements be submitted to the NRC.
We have reviewed Combustion Engineering letters dated February 27 and September 18, 1987 which described the System 80 plant's compliance with the ATWS Rule.
We find that the information provided is not sufficient to determine compliance with the ComIission's regulations.
Therefore, we ask that the in-formation requested by the Enclosure be provided within 30 days from receipt of this letter, or provide an alternate schedule for doing so within 15 days.
The reporting and/or recordkeeping requirements of this letter affect fewer than ten respondents; therefore, OHB clearance is not required under P.L.96-511.
Sincer
Enclosure:
As stated erence L. Chan, Senior Project Manager Project Directorate V
Division of Reactor Projects III, IV, V and Special Projects Office of Nuclear Reactor RegulationI cc:
See next page
Mr. Donald B. Karner Arizona Nuclear Power Project Executive Vice President Post Office Box 52034 Phoenix, Arizona 85072-2034 Palo Verde CC:
Arthur C. Gehr, Esq.
Snell 5 Wilmer 3100 Valley Center Phoenix, Arizona 85073 Charles R. Kocher, Esq. Assistant Council James A. Boeletto, Esq.
Southern California Edison Company P. 0.
Box.800
- Rosemead, California 91770 Mr. Tim Polich U.S. Nuclear Regulatory Commission HC-03 Box 293-NR Buckeye, Arizona 85326 Regional Administrator, Region V
U. S. Nuclear Regulatory Commission 1450 Maria Lane Suite 210 Walnut Creek, California 94596 Mr. Charles B. Brinkman Washington Nuclear Operations Combustion Engineering, Inc.
12300 Twinbrook Parkway, Suite 330 Rockville, Maryland 20852 Mr. Charles Tedford, Director Ar izona Radiation Regulatory Agency 4814 South 40 Street Phoenix, Arizona 85040 Chairman Maricopa County Board of Supervisors 111 South Third Avenue Phoenix, Arizona 85003
ENCLOSURE 1
RE VEST FOR ADDITIONAL INFORMATION ON ATMS REVIEM PALO VERDE NUCLEAR GENERATING STATION UNITS 1 2 5 3 (1)
The staff has reviewed Combustion Engineering letters dated February 27 and September 18, 1987 with respect to System 80 plant's compliance with the ATMS Rule (10 CFR 50.62).
The first letter described how through the use of System 80 CESSAR that Palo Verde complied with, the ATMS Rulc.
The second lettei forwarded CEN-362 which 'fs CE's response to the NRC's evaluation of CEN-315.
The purpose of CEN-362 is to demonstrate that the AFAS fn the System 80 plants complfes with the ATMS Rulc.
It is the staff's understanding that the Supplementary Protection System (SPS) has all of the features of a Diverse Scram System (DSS) with the added feature of having been upgraded to safety-grade status.
The SPS is diverse from the RPS with respect to the components and hardware and it is sctpoint-coordinated such that the RPS is actuated first.
The SPS also causes a reactor trip through diverse means. i.e.,
a contactor vs a-circuit breaker.
In addition, thc SPS will not interfere with the RPS and is not requfred for the safe shutdown.
The System 80's SPS has all of the qualities and characteristics of a diverse scram system.
Diverse scram systems augment thc RPS and/or the RTS, they do not replace it.
The descriptions of the SPS fn CEN-362 present no new data with respect to the diversity of the AFAS from thc RPS.
On February 27, 1989, the staff met with the Combustion Engfneerfng Owners Group (GEOG) which operate Arkansas Nuclear One Unit 2, San Onofre Units 2 and 3, and Waterford Unit 3.
The staff reiterated the importance of meeting the dfvcrsfty requirements of the ATMS Rule and the immediate need to resolve the Auxiliary Nftfgatfng System Actuation Circuitry (AMSAC) implementation issue.
It was suggested that the GEOG seriously consider
, other design options such as a non-safety grade AMSAC with diverse
I 1J sensors as the initiation signal.
The ANSAC signal will be overridden by the safety AFAS signal in the event of a design basis event such as a steam generator rupture.
The GEOG has agreed to provide a preliminary design within the next two weeks.
The staff has agreed to review the conceptual design prior to implementation similar to the BKM plant approach now being used.
I It is the staff's preliminary finding that the Palo Yerde's auxiliary feedwater actuation system does not meet the diversity requirement of the ATMS Rule.
Therefore, the staff requests the licensee to provide an alternative design to meet the ATWS Rule.
(2)
Based on the staff's review of CE letters dated February 27, and September 18, 1987, the following list of questions was generated.
Please provide the response to these questions.
(a)
Provide detail and show on a block diagram the selective logic network that opens the NG set output load contactors.
(b)
On the selective logic network block diagram indicate the control grade portion of the circuits and show the location of the isolators.
(c)
Expand Figures I and 2 in CEN-362 to show the power supplies and their source of power.'d)
Contrary to the statement in CEN-362, the diverse reactor trip and diverse turbine trip have not been resolved.
Provide the details showing how these two trip systems are in conformance with the ATMS Rule implementation guidance.
(e)
Provide the isolator quali'fication data requested by Attachment 1.
~'
ATTACMNENT 1
ISOLATION DEVICE RE VEST FOR ADDITIONAL INFORMATION Each light-water-cooled nuclear reactor shall be provided with a system for the prevention and/or mitigation of the effects from anticipated transient without scram (ATMS) events.
The Ceanission-approved requirements for the prevention/mitigation of ATMS events are defined in the Code of Federal Regulations (CFR) Section 10 paragraph 50.62..
The staff has determined that the isolation devices used within ATWS prevention/mitigation systems (to provide isolation between class 1E and non-class 1E circuits or between redundant class lE circuits) will be reviewed on a plant-specific basis.
The following additional information is required to continue and complete the plant-specific isolator review:
Isolation Devices Please provide the following:
a.
For the type of device used to accomplish electrical isolation, describe the. specific testing performed to demonstrate that the device is acceptable for its application(s).,
This description should include elementary
- diagrams, when necessary, to indicate the test configuration and should describe how the maximum credible faults were applied to the devices.
b.
Data to verify that the maximum credible faults applied during the test were the maximum voltage/current to which the device could be exposed, and define how the maximum voltage/current was determined.
I~
c.
Data to verify that the maximum credible fault was applied to the non-Class lE side of the device in the transverse mode (between signal and return) and that other faults were considered (i.e., open and short circuits).
d.
Define the pass/fail acceptance criteria for each type of device.
e.
A comoitment that the isolation devices comply with the environmental qualifications (10 CFR 50.49) and seismic qualifications that were the, basis for plant licensing.
f.
A description of the measures taken to protect the safety systems from electrical interference (i.e., Electrostatic Coupling, EMI, Common Mode and Crosstalk) that may be generated by the ATMS circuits.
9 ~
Information to verify that the Class 1E isolator is powered from a Class 1E source.
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