ML20137F393

Deletion of Turbine Trip Test at Test Condition 3 from Power Ascension Test Program During Conduct of Test Number 25-Turbine Trip & Generator Load Rejection, Safety Evaluation

ML20137F393
Person / Time
Site:	Hope Creek
Issue date:	08/20/1985
From:	Public Service Enterprise Group
To:
Shared Package
ML20137F347	List: ML20137F342 ML20137F349 ML20137F361 ML20137F368 ML20137F393 ML20137F427
References
PSE-SE-Z-001, PSE-SE-Z-1, NUDOCS 8508260207
Download: ML20137F393 (6)

Text

PUBLIC SERVICE ELECTRIC AND GAS COMPANY HOPE CREEK PROJECT SAFETY EVALUATION No. PSE-SE-Z-001 TITLE: DELETION OF TURBINE TRIP TEST AT TEST CONDITION 3 FROM THE POWER ASCENSION TEST PROGRAM DURING CONDUCT OF TEST NUMBER 25 - TURBINE TRIP AND GENERATOR LOAD REJECTION Date: AUG 201985 1.0 PURPOSE The purpose of this Safety Evaluation is to document the results of the evaluation performed to delete the Turbine Trip Test at Test Condition 3 and change the Generator Load Rejection Test at Test Condition 1 or 2 to a Turbine Trip Test in the Power Ascension Test Program.

2.0 SCOPE The area of concern for this proposed change is the ~

adequacy of the Power Ascension Test Program.

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3.0 REFERENCES

1. FSAR Chapter 14

2. GE Startup Test Specification No. 23A4137 Rev. 0

3. NRC Regulatory Guide 1.68, August 1978'.

4. Hope Creek Generating Station Draft Technical Specifications 2

4.0 DISCUSSION Regulatory Guide 1.68 (Revision 2, August 1978), Appendix A, paragraphs 5.1.1 and 5.n.n require that a Turbine. Trip and Generator Load Rejection to be performed at 100%

power to demonstrate that the dynamic response of the plant is in accordance with design requirements for turbi'ne trip and full load rejection. These tests may be combined if a turbine trip is initiated directly during the generator load rejection instead of tripping from secondary effects such as a turbine overspeed trip. Test Number 25, Turbine Trip and Generator Load Rejection, is currently planned to be performed at three conditions during the Power Ascension Test Program; 1) a generator PSE-SE-Z-001 1 of 3 G508260207 850821

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load rejection during Test Condition 1 or 2 (within the bypass capacity of the plant); 2) a turbine trip during Test Condition 3 (approximately 75% power); and 3) a generator load rejection at Test Condition 6 (approximately 100% power). It is proposed to delete the Turbine Trip Test at Test Condition 3 and change the Generator Load Rejection Test at Test Condition 1 or 2 to a Turbine Trip Test. This proposed testing will demonstrate that Regulatory Guide 1.68 objectives are met. '

Response of the system during a turbine trip and generator load rejection is determined by analyzing test data and comparing to acceptance criteria, level 1 and-level 2, which define the required system performance.

The generator load rejection (Test Condition 6) and the turbine trip (Test Condition 1 or 2) provide data to demonstrate that the level 1 and 2 criteria are met during a turbine trip. The turbine bypass system performance will be verified at a lower power level by changing the proposed generator load rejection at Test Condition 1 or 2 to a turbine trip. Because of the enhanced data acquisition system available, integrated 3 system response to a turbine trip can be obtained from the Generator Load Rejection Test at Test Condition 6.

Control systems which regulate the long term operation -

following the transients are separately tested during the Power Ascension Test Program. Feedwater and level '

control system tuning in Test Number 21 (ST Feedwater System Response) will ensure proper water level control. High and low water level trip avoidance will be verified in the Generator Load Rejection Test at Test Condition 6. Pressure control tuning during Test Number 20 (ST Pressure Regulator testing) will ensure that the MSIV closure trip on low turbine inlet pressure is avoided during the transient.

5.0 CONCLUSION

Current testing of the generator load rejection at 100%

power, satisfies the requirements imposed by Regulatory Guide 1.68 (Revision 2), Appendix A, paragraphs 5.1.1 and 5.n.n. In addition, the proposed' Turbine Trip Test within~ bypass valve capacity (Test Condition 1 or 2) provides additional verification of the response of the protective systems and also provides demonstration of the bypass system's capability to avoid scram at low-power levels.

PSE-SE-Z-001 2 of 3

The Turbine Trip Test has been previously demonstrated to be a mild transient event and poses no serious threat to the core and reactor integrity (Reference FSAR Section 15.2.3). In addition, the transient results fron a generator load rejection at full power are more limiting than the results from a turbine trip at Test Condition 3 (Table 1).

A Technical. Specification change is not required and safety related systems or safe operation of the plant is not affected. Therefore, the changes do not involve an unreviewed safety question.

6.0 DOCUMENTS GENERATED -

NONE 7.0 RECOMMENDATIONS The FSAR and Startup Test Procedures shall be revised to reflect the changes to the Turbine Trip and Generator Load Rejection testing during the Power Ascension.

8.0 ATTACHMENTS Table 1, Startup Data Comparison 9.0 SIGNATURES Originator // ~~

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' Datd Group Head (or SSE) buttto ddt R/h/9[

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• s TABLR 1 STARTUP DATA COMPARISON Grand Gulf-l Kuo Sheng 1 Kuo Sheng 2 LaSalle 2 Susquehanna 1 LR TT LR TT LR TT LR TT LR TT Power / Flow 99.7 72.1 97 74 95.8 75.1 95.7 69 99.9 75  :

97.8 96.4 99.4 100 99.1 99.9 93.1 93 98.8 100 Initial Dome 1023 989 985 978 981 972 999 967 1010 980 Proesure (paig)

• Peck Dome 1111 1044 1045 1009 1052 1004 1078 1030 1075 1043 Pres. (psig)

Dome Press 88 55 60 31 71 32 79 63 81 63 (psi)

Heat Flux 0 0 0 0 0 0 0 0 0 0 (1 NBR) l I

LR = Load Rejection

! TT = Turbine Trip 1

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TEST NUMBER 27 - RECIRCULATION FLOW CONTROL SYSTEM TEST SIMPLIFICATION OBJECTIVE:

Regulatory Guide 1.68 ( Revision 2, Augus t 1978), Appendix A, paragraph 5.s requires that the recirculation flow control system be calibrated as necessary and performance verified, and paragraph 5.h.h requires that the dynamic response of the plant to design load swings be demonstrated to be in accordance with design. Hope Creek's Power Ascension Test Number 27, Recirculation Flow Control System, determines the plant response to changes in recirculation flow, optimizes settings of the master flow controller and demonstrates plant loading capabilities. Testing is performed along the 50%

load line between Test Conditions 2 and 3 and along the 100%

load line between Test Conditions 5 and 6 of FSAR figure 14.2-4. It is proposed to simplify the testing by reducing the number of intermediate flow conditions and testing inputs (ramp and step demands) and to delete the Automatic Load Following (ALF) testing and associated response criteria.

DISCUSSION:

Response of the system is determined by analyzing test data and comparing to acceptance criteria which define the ,

required system performance. Testing of the recirculation speed loops is performed at the 50% load line using large plus and minus step changes and the speed controller gains are optimized. After the speed loops have been optimized, the system may be switched to master manual modo and the master controller is tested to obtain acceptable response in the manual mode. Following these tests the master controller is switched to the Automatic Load Following mode (ALP) for optimization of that control loop. When the plant is tested along the 100% load line, the recirculation system is tested by inserting small plus and minus step changes in the local manual and master manual modes. The automatic load following loop is also tested by means of small load demand changes.

Prior to the power ascension test program, predictions of system behavior will be performed to aid in the tuning of the Recirculation Flow Control System. In addition to this analysis, previous test experience from similar plants will be used to provide best estimates for initial controller settings. Bench calibration of the controllers using these best estimate settings will be performed during the preoperational phase of testing. As a result of analysis and bench calibration of controllers, the number of intermediate PAGE 1 16-Aug-85

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and test inputs (ramp and step demands) required to achieve the desired system performance can be reduced. ALF testing i

and associated response criteria can be deleted since the ALF function will be disabled.

CONCLUSION:

l The subject test can be simplified by using pretest analysis l and bench calibration of controllers to minimize the number l of intermediate flow conditions and test inputs of the test.

I All criteria of the currently planned test will be satisfied (with the exception of the ALF testing which is the subject of a separate writeup), and the objectives of Regulatory Guide 1.68 (Revision 2, August 1978), Appendix A paragraphs i 5.s and 5.h.h will be satisfied. In addition, safety systems l or the safe operation of the plant is not affected. Based on j the above, the simplifications do not involve an unreviewed l

safety question. Therefore, Hope Creek's Power Ascension Test Number 27, FSAR Table 14.2-5, Recirculation Flow Control System, can be simplified using pretest analysis and bench calibration of controllers to reduce the number of l

intermediate flow conditions and test inputs (ramp and step demands).

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