ML20246L277
| ML20246L277 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 07/10/1989 |
| From: | William Cahill TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| TXX-89457, NUDOCS 8907180386 | |
| Download: ML20246L277 (7) | |
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Log # TXX-89457 l-- m File # 10010 914.2 Ref. # 10CFR50.30(b) 1UELECTRIC July 10,1989 DUi$r$li U, S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C.
20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NO. 50-445 UNIT 1 POWER ASCENSION TEST PROGRAM
REFERENCE:
- 1. TV Electric letter TXX-89139 dated M&rch 22, 1989 from W. J. Cahill, Jr. to the NRC
- 2. TV Electric letter TXX-89395 dated June 23, 1989 from W. J. Cahill, Jr. to the NRC Gentlemen:
Comanche Peak is preparing for Unit 1 power ascension by thoroughly investigating lessons learned from other utilities, particularly recent Westinghouse PWR startups.
The changes transmitted in Amendment 76 to the CPSES FSAR reflect the results of this investigation.
The Performance and Test group responsible for the power ascension test program has been augmented with personnel who have extensive experience at recent startups including Westinghouse, Combustion Engineering, and General Electric plants. They have been integrated into the operating staff to ensure that lessons learned from other startups are incorporated into the CPSES Unit 1 Power Ascension Program.
The test procedures are reviewed by the Station Operations Review Committee via a subcommittee and are approved by the Plant Manager.
The testing program administrative procedures are approved by the Vice President, Nuclear Operations. The program has extensive ties with the Training Department to ensure that data on actual plant transients are compared with simulator performance for realistic operator training. The plant transient test procedures will have been run on the simulator to the extent practicable prior to actual performance to thoroughly familiarize operators with the plant manipulations and the responses expected, to ' debug' the procedures as well as to elicit a close working relationship between operators and test engineers.
Recent operating staff performance during Hot Functional Testing and the Integrated Leak Rate Testing demonstrate that CPSES personnel are committed to quality and will be capable of operating the plant safely. Additional staff experience will be gained during the forthcoming Integrated Test Sequence, during which Engineered Safety Features actuations and ECCS actuations will be demonstrated.
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TXX-89457 July 10,1989 Page 2 of 5 TU Electric has made several changes to the FSAR to incorporate lessons learned from industry experience in Initial Startup. These modifications were developed in conjunction with, and with the full support of, Westinghouse as described in Enclosure 1~
One of the key features is the deletion of a discrete, evaluated test sequence at 25-30% power and combining the evaluation.
of test data previously scheduled for the 25-30% plateau with the 50% plateau and self assessment period. We believe this change is beneficial to plant reliability and operator performance. We still intend to conduct a tiorough, rigorous, and deliberate transition from low power to 50%, carefully monitoring plant response while placing systems in service. During the NRC site visit of June 20, 21 and 22, the NRC requested that TU Electric submit additional justification for the elimination of the previously planned 25-30%
power plateau testing. The elimination of the 25-30% region as a plateau and a discussion of the 50% power self-assessment are discussed balow.
Reference 1 described the testing previously performed at 25-30% power (10%
Step Load Transient test, and the Automatic Reactor Control System test and the Core Performance Evaluation Flux Maps) and provided just!fication for either changing the power level at which the test was performed or deleting the 25-30% power test. Additional justifications have been presented in the meetings and discussions held with the NRC related to this issue. A summary of the justifications is provided as follows:
- 1. 10% Steo load Transient: This test evaluates plant control system response to a 10% down power step change followed by a 10% up power step change. The results of this test are used to perform tuning on the various control systems. Tuning of control systems at 25-30% power (unit load transient) has been found not to be useful by other nuclear utilities because some of the B0P systems are either not fully operative (e.g., heater drains) or are operating in the lower acceptable end of their operating range (e.g., feedwater control valves).
Industry experience has shown that significant tuning at low power levels can be detrimental to successful operation at higher power i
level s.
In addition, plant response prior to tuning may not be similar I
to the response during subsequent startups after tuning so that l
performing this test at 25-30% power will not provide useful operator training experience. As described in the Amendment 76 submittal, this l
test will be performed at 50% power.
- 2. Automatic Reactor Control System Testina: This test perturbs Tave and verifies proper reactivity control system response to restore Tave to its control band. This test is independent of power level and can be performed at any power level where the seconde.ry plant is stcble. TU Electric has elected to move this test to 50% power to limit the time spent at low power where plant systems are not fully in service.
TXX-89457 j'
duly 10,.1989 Page 3 of 5
- 3. 25-30% Flux Mao: Acceptance criteria are established for the Hot Zero Power. flux map and for Control Rod Reactivity Worths testing (Rod Swap).
to determine acceptability for proceeding directly to 50% power without taking a-25-30% flux map (Reference 2). Should~ these criteria not be met, a 25-30% flux map will be taken.
- 4. ' RCS Flow Measurement: This test measures Reactor Coolant System flow using the N-16 associated Transit Time Flow Meter iTTFM) system. The vendor, Westinghouse, believes that prior to in pioces:: calibration of' the N-16 monitors during power ascension, the measured RCS flow values at 25-30% power will not be sufficiently accurate to warrant testing at this power.
After considering the effect of eliminating the need to perform the above tests at 25-30% power, the. requirement to establish a 25-30% plateau was deemed to be unnecessary.. Instead, several " hold points" are established en route to 50% power.
In the context used here a " hold point" is different from a " plateau" in that a " hold point" is maintained to accomplish specific-planned activities, whereas a " plateau" corresponds' to the Regulatory Guide' l.68 recommended " selected milestone throughout the power-ascension test phase to ensure that relevant test results are evaluated and approved by personnel or groups designated by the applicant prior to progressing with power-ascension test phase".
" Hold points" are established en route to 50% power to obtain statepoint data (precision calorimetric) for core performance, perform gross calibration adjustments of the Nuclear Instrumentation System, perform primary and secondary chemistry analyses, and to perform testing of certain B0P systems as they are placed into service.
The following is a list of tests and the approximate power levels that the tests are intended to be performed en route to 50% power:
<10% ISU-202A - Steam /Feedwater Flow ISU-205A - Steam Dump Operation ISU-207A - Steam Generator Water Level Control Test ISU-212A - Piping Vibration ISU-220A - Main Turbine Overspeed Trip Test ISU-224A - Statepoint Data Collection ISU-238A - Main Feedwater Test EGT-322A - Main'Feedwater Pump Testing EGT-327A - Steam Generator Atmospheric Dump Testing
<20% ISU-207A - Steam Generator Water level Control Test ISU-212A - Piping Vibration Test ISU-238A - Main Feedwater Test
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V TXX-89457 July 19, 1989 Page 4 of 5
<30% ISU-006A - Chemistry Control ISU-020A
.Startup Adjustments of Reactor Controls (T-ref and turbine impulse pressure)
ISU-202A'- Steam /Feedwater Flow ISU-204A - NIS Calibration ISU-207A - Steam Generator Water Level Control System Test ISU-211A - Loose Parts Monitoring-ISU-224A - Statepoint Data collection ISU-226A - N-16 Calibration ISU-308A - Thermal Expansion Measurements EGT-326A - Steam Dump Capacity The results 'of. the above. tests will all be thoroughly evaluated at the 50%
plateau by the Test Review Grou;. and the Station Operations Review Committee prior to exceeding.50% power.
In sum, the plateau deletion at 25-30% power is intended to limit the time spent at low power levels because it unnecessarily challenges operators, and because actual plant transient testing.does not.
generate useful engineering data or training opportunities. The testing that is planned during this transition is primarily data gathering, and we intend to make adjustments to plant control systems only as required to permit continued transition to 50%. This position is supported by our NSSS vendor and industry experience.
While at 50% power, TU Electric plans to perform a self-assessment of CPSES Unit l's readiness to operate at full power. This detailed self evaluation will be performed to provide additional assurance that the power ascension test program is being performed as intended, operator proficiency is satisfactory, problem areas have been identified and resolved, and that the plant and the operators are ready for the ascension to full power.
During the self-assessment,.each of the functional areas listed below will be monitored and evaluated against established performance objectives and standards of excellence. The evaluation teams will be selected by cognizant area managers who will serve as team leads. The assecsment will be augmented by the Plant Evaluation Manager and the Independent Safety Engineering Group to provide independence in the evaluation process. This assessment will also serve to measure the effectiveness of the Operational Readiness Program currently implemented at CPSES.
The following six functional areas were selected based upon their direct relationship to the safety of power operations:
- 1. Plant Operations
- 2. Licensing Compliance
- 3. Radiation Protection
- 4. Maintenance / Work Control
- 5. Testing
- 6. Chemistry
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TXX-89457 July 10,1989 Page 5 of 5' Additional areas of review may be identified during power ascension to be included in the 'self-assessment. Actual events observed during plant evolutions up to that time will be evaluated with relative strengths and weake, esses identified. The results will be submitted to the Station Operations Review Committee (SORC) for review. The SORC will then recommend to the Vice President, Nuclear Operations corrective actions'for those areas evaluated as needing improvement.
The'self-assessment will begin at Initial Criticality and continue through power ascension up to and including the 50% plateau. After the major tests are' performed at 50% power, the plant will be held at the 50% plateau for one to two weeks to carry out the assessment and evaluation of the results by the-SORC and station management. At this time corrective actions will be-prescribed as necessary and a determination made as to the readiness of the-facility and its personnel to operate safely at 100% power.
TU Electric is finalizing the procedures, objectives and other documents needed to' implement this program, all of which will be available for review once completed.
TU Electric believes that its preparations for power ascension, the modified -
power ascension testing program and self-assessment will ptovide additional assurance that Comanche Peak will be operated safely.
Sincerely, MMM % Map /,
William J. rthill, Jr.
By:
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R. D. Walker Manager, Nuclear Liunsing BSD/ddm Enclosure c - Mr. R. D. Martin, Region IV Resident Inspectors, CPSES (3)
. Enclosure 1 to TXX-89457
_ July 10. 1989
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WPT-11552
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f C Co Dietlen mm u2mn June 30, 1989 NS-0PLS-0PL-II-422 Mr. W. J. Cahill, Jr., Executive Vice President Nuclear Engineering & Operations S.0. No. TBX/TCX-4705 TU Electric Company P. O. Box 1002 Glen Rose.. Texas 76043 TV ELECTRIC COMPANY COMANCHE PEAK STEAM ELECTRIC STATION Comanche Peak Startun Test Procram Suonort
Dear Mr. Cahill:
At the request of TU Electric the following is provided in support of Comanche Peak's proposed modifications to the Startup Test Program.
Comanche Peak is similar in design to many four loop plants with a 1
The fuel pattern noted for cycle one is not unlike the fuel patterns of other Westinghouse designs. We believe the tests scheduled for 0%, 50%, 75%, and 100% Rated Thermal Power (RTP) are a planned and systematic approach to full power operation and will insure the adequacy of the plant and core design. The deletion of the tests in the Comanche Peak submittal dots not result in an unreviewed safety concern nor does it increase the probability or consequences of an event analyzed in the FSAR.
Westinghouse participated in the development of and reviewed the suodifications submitted unoer letter TXX 89139 from W.J. Cahill to the Nuclear Regulatory Commission dated March 22, 1989. These modifications are based on, and are consistent with our recommendations on; necessary tests, acceptance critsria, l
and requitad actions if the acceptance criteria is not satisfied.
In Westinghouse's opinion the Power Ascension Test Program submitted under the March 22ndletterandlaterpresentedonApril6th1989withsubsequent information submitted in TXX-89395 dated June 23, 1989 represents a gradual and prudent approach to full power with sufficient hold points to assure proper operation and calibration of control and protection systems.
In soint, calibration of the control systems can be better accomplished at the hig1er sower level because of the stability of the Balance of Plant systems at the tigher power level.
In Westinghouse judgement, the Power Ascension Testing Program as presented to the NRC will reduce Comanche Peak's vulnerability to trips and unnecessary transients.
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t WPT-11552 W. J. Cahill, Jr. It is Westinghouse's osinion that the Power Ascension Test Program, as proposed on the Comancie Peak docket, is acceptable and will result in verification of proper operation of all required systems prior to escalation to 100% RTP and subsequent commercial operation. Westinghouse recoseends that TU Electric implement the Mwer Ascension Test Program after NRC ' acceptance.
If you have any questions please do not hesitate to contact us.
Very truly yours, WESTINGHOUSE ELECTRIC CORPORATION
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J. L. Vota, Manager D.Cecchett/jjs/063089 Comanche Peak Projects cc:
W. J. Cahill, Jr.
IL J. W. Beck IL C. B. Hartong 1L A. B. Scott IL ARMS IL, IAR D. P. Barry IL J. J. Kelley IL T. Elkins IL K. B. Gooden IL VETIP Coordinator IL H. D. Bruner IL C. B. Hogg IL M. R. Blevins IL J. R. Marshall IL R. D. Walker IL S. Ellis IL J. Rodriguez IL
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