ML20138G497
| ML20138G497 | |
| Person / Time | |
|---|---|
| Site: | Hope Creek  |
| Issue date: | 10/11/1985 |
| From: | Public Service Enterprise Group |
| To: | |
| Shared Package | |
| ML20138G467 | List: |
| References | |
| PSE-SE-Z-016, PSE-SE-Z-16, NUDOCS 8510250488 | |
| Download: ML20138G497 (10) | |
Text
a Y
PUBLIC SERVICE ELECTRIC AND C\\S COMPANY HOPE CREEK PROJECT SAFETY EVALUATION No. PSE-SE-2-016 TITLE:
SIMPLIFICATION OF DRYWELL PIPING VIBRATION, TEST NUMBER 31 Date:
OCT 11 BBS 1.0 PURPOSE The purpose of this Safety Evaluation is to document the results of the evaluation performed to ensure that the deletion f rom Tes t Number 31, Drywell Piping Vibration, of the dynamic transient measurements made during the recirculation pump trips and restarts will not adversely affect reactor safety.
2.0 SCOPE The area of concern for this proposed change is the adequacy of the drywell piping vibration testing which is being performed during the power ascension test program.
3.0 REFERENCES
1.
FSAR Chapter 14 and Chapter 3.9 2.
GE Startup Test Specification No. 23A4137 Revision 0 3.
NRC Regulatory Guide 1.68 August 1978 4.
Hope Creek Generating Station Draft Technical Specification 5.
Hope Creek Power Ascension Test Procedure TE-SU.BB-342(O), Recirculation System Piping Dynamic Response.
4.0 DISCUSSION Regulatory Guide 1.68 (Revision 2, Augus t 1978), Appendix l
A, paragraph S.o.o requires verification by observation and measurements, as appropriate during power ascension testing, that piping and component movements and i
hydO2504aB851017 A
ADOCK 05000354 PDR PSE-SE-2-016 1 of 3
+
vibrations are acceptable for (1) ASME Code Class 1, 2,
?
and 3 systems, (2) other high-energy piping systems inside Seismic Category I structures and (3) high energy portions of systems whose failure could reduce the functioning of any Seismic Category I plant feature to an unacceptable level.
Test Number 31 satisfies Regulatory Guide 1.68 by verifying that main steam and recirculation piping inside the drywell is within acceptable dynamic transient vibration and deflection limits during the following transients:
(1) single recirculation pump trip at Test Condition 3 and Test Condition 6, (2) recirculation pump restarts, (3) turbine stop valve trips / generator load rejections at Test Conditions 2 and 6, and (4) manual safety relief valve (SRV) discharge at rated pressure and SRV discharge during planned transients.
It is proposed that testing during transients (1), and (2), be eliminated and that only testing during turbine stop valve trip (transient (3))
1 and SRV discharge (transient (4)) be retained.
Note that i
it was originally planned to take vibration data during a turbine trip at Test Condition 3; deletion of the Test i
Condition 3 Turbine Trip was the subject of PSE-SE-2-001.
Previous plant startup results indicate that vibration and deflection measurements of recirculation piping during recirculation pump trips and restarts are well below the prescribed limits.
For example, data collected from dynamic transient vibration tests at Susquehanna-1, summarized in Table 1, shows the measured vibrations for the recirculation pump trip and restarts are well within the expected range and are significantly below the allowable range.
As a consequence, pipe stress levels were well within code limits.
The power / flow characteristics and the recirculation pump and piping design (see attached Table 2) of Susquehanna are very similar to Hope Creek.
The response measured at Susquehanna is indicative of the expected response at Hope Creek and thus provides a basis for deleting the single recirculation pump trip and restart at Hope Creek.
5.0 CONCLUSION
S I
Recirculation system piping vibration and deflection dynamic transient test data collected f rom similar plants have been found to be well below expected and allowable ranges for recirculation system transients.
Therefore, the remaining testing performed by Test Number 31 will satisfy the requirements of Regulatory Guide 1.68 (Revision 2) Appendix A, paragraph'5.o.o.
Based on the PSE-SE-2-016 2 of 3
k above discussion, the proposed change will not adversely affect any safety systems or the safe operation of the plant, and as such does not involve an unreviewed safety question.
A change to Hope Cr;ek's Technical l
Specifications is not required as a result of the testinq change.
Therefore, recirculation piping vibration and deflection measurements made during recirculation pump trips and restarts can be eliminated from Hope Creek's power ascension testing program.
6.0 DOCUMENTS GENERATED None 4
7.0 RECOMMENDATIONS Chapters 14 and 3.9
.f the PSAR and startup test procedures shall be revised to reflect the changes to the recirculation piping systems dynamic transier.t tes t. i ng
-i during the power ascension test program.
8.0 ATTACHMENTS Table.1 and Table 2 9.0 S_lGNATURES Originator 1
/o/N!##
Ve ri f ie r 4
m p / f5' t SSE)
I W
Group Head /(
l e-Systems Analysis Group Head A,(
dth f$.
I s
Datet Site Engineering Manager (h ked i /QM d //g Date PSE-SE-2-016 3 of 3
i
?
o ATTACHMENT 1 TdBLE 1 SLS@EHAN.NA-1 TRANSIENT '.'ISRAT:
CN TESTS 1
AS PEASURED level 1 LE'!:L2 MAXIMt;M
'9LE EXPECTE',
TEST PEAK-TO-PEAK E'/ENT CONC:7 ION (MILS)
RAN3E 5)
(MILS:
Pan; Trip / Restart 3
20.8 110 Pu,p Trio / Restart 3
27.0 110 GO Puno Trip / Restart 4
60 S.2 15C 76 TABLE 2 COMPA11Sch 0F REC:RCULAi!ON SYSTEM PARAM Pietri HC?E CREEK S USQUCHA N*.A - 1 Sucti:n 26" NPS Discharge 28" NPS 28" NPS header 28" NPS 22" NPS Riser 22" NPS 12" NPS J2" NPS Distar:e fr:n PFv Invert HeritentalSueti-Pipe /Va} vee 27' PumpCischargePipe/ValveE 25 i,-
21'-7" 21'-7" Recirculatiot Pu9p/ Motor Putp Manufacturer Byron-Jack s:-
Pamp Rated Speed (RPM)
Byron-Jacksoa 1668 Puep Brake Horsepower.(SHP) 1668 1
7050 Motor Manufacturer 7050 GE Motor Input Power (W)
GE 5650 Rotating Inertia (Ib -ft )
5650 2
f 20,500 (pump, motor and M-G set) 20.500 NPS e Nomiral pipe size HOPE CREEX GENERATING STATION PAGE 4 10/8/85
I GEHERAL ELECTRIC COMPANY TECHNICAL ANALYSIS HOPE CREEK GENERATING STATION TEST NUMBER 31 - DRYWELL PIPING VIBRATION TEST SIMPLIFICATION OBJECTIVE:
Regulatory Guide 1.68 (Revision 2: August 1978), Appendix A, paragraph 5.o.o requires verification by observations and measurements during power ascension testing, as appropriate, that piping and component movements and vibrations are acceptable for (1) ASME Code Class 1, 2,
and 3 systems, (2) other high-energy piping systems inside Seismic Category 1 structures, and (3) high-energy portions of systems whose failure could reduce the functioning of any Seismic Category 1 plant feature to an unacceptable level.
Test Numbe r 31, Drywell Piping Vibration, verifies that main steam and recirculation piping vibration is within acceptable limits.
During the operating transient load testing the amplitude and displacement and number of cycles per transient of the main steam and recirculation piping will be measured.
Remote vibration and deflection measurements are taken during the following transients (1) recirculation pump start, (2) recirculation pump trip at approximately 100% of rated flow, (3) turbine stop valve trip or load rejection at approximately 100% power, and (4) manual discharge of each safety / relief valve (S/RV) at rated pressure and during planned transient tests thct result in S/RV discharge.
It is proposed to eliminate the remote vibration and deflection measurements taken during the recirculation pJmp trips and restarts.
DISCUSSION:
Acceptable response of the main steam and recirculation piping duririg operating transient load testing is determined by analyzing test data and comparing the results to acceptance criteria which define t'e systems' required performance.
Level I criteria require that operating transient limits for loads on piping and suspension are within safe limits, and operating vibration limits keep piping stresses and pipe-mounted equipment accelerations within safety limits.
Level 2 criteria require that operating transient limits for loads on piping and st s =qsion are within expected limits, and operating vibration lim 4'.s keep piping stresses and pipe-mounted equipment accelerations within expected limits.
1
Previous plant startup results indicate that vibration and deflection measurements of recirculation piping during recirculation pump trips and restarts are always well below the prescribed limits.
As an example, transient vibration test results a t Susquehanna-1, summarized in Table 1, show that the measured vibrations for the recirculation pump trip / restart are well within the expected range and are significantly below the allowable range.
Susquehanna-1 is a BWR/4, 251 inch vessel with the same power / flow characteristics and recirculation / steam piping design as Hope Creek Generating Station.
Table 2 shows that the Hope Creek Generating Station and Susquehanna-1 recirculation piping systems are similar in pipe size and distance from the reactor pressure vessel (RPV) invert and have the same recirculation system pump and motor.
The suspensions of the two recirculation systems differ in the number and size of snubbers at the various sections of the piping system.
However, the snubber differences are not a factor during steady state or transient dynamic vibration testing because the deflections are small and the snubbers do not lock up during the testing.
The principal contributors to the amplitude of the recirculation line vibration, based on operational experience and analysis, are the pump and motor imbalance, the pipe sizes and length of the piping system.
Table 2 shows that these parameters are very similar for Hope Creek Generating Station and Susquehanna-l.
The data from Susquehanna-1 tests, and all previous startup tests, demonstrate that the results of the vibration testing of the recirculation system piping during recirculation pump trips / restarts are well within prescribed limits.
The response measured at Susquehanna-1 is indicative of the expected response at Hope Creek Generating Station and thus provides a basis, including the experience of all other plant startups, for deleting' the recirculation pump (s) trip and restart vibration data at Hope Creek Generating Station.
2
j't 4
I 4
TABLE 1 SUSOUEHANNA-1 TRANSIENT VIBRATION TESTS 1
AS MEASURED LEVEL 1 LEVEL 2 M AXIMUM ALLOWABLE EXPECTED TEST PEAK-TO-PEAK RANGE RANGE l
EVENT CONDITION (MILS)
(MILS)
(MILS)
[
Pump Trip / Restart 3
20.8 110 60 Pump Trip / Restart 3
27.0 110 60 Pump Trip / Restart 4
5.2 150 76 TABLE 2
}
COMPARISON OF RECIRCULATION SYSTEM PARAMETERS
.i i
a PIPING HOPE CREEK SUSOUEHANNA-1 4
Suction 28" NPS*
28" NPS Discharge 28" NPS 28" NPS Header 22" N PS 2 2" N PS
]
Riser 12" NPS 12" NPS DISTANCE FROM RPV INVERT C
Horizontal Suction Pipe / Valve L 27' 1 1/2" 25' - 11" C
Pump Discharge Pipe / Valve L 21' - 7" 21' - 7" RECIRCULATION PUMP / MOTOR i
Pump Manufacturer Byron-Jackson Byron-Jackson Pump Rated Speed (RPM) 1668 1668 Pump Brake Horsepower (BHP) 7050 7050 Motor Manufacturer GE GE Motor Input Power (KW) 5650 5650 Rotating Inertia (1bg-ft2) 20,500 20,500 (pump, motor, and M-G set)
'NPS = Nominal pipe size l
1 3
i l
1
- ~.-.. -
.. - -.. _ ~..
)
4
's s 5
}
CONCLUSION:
9 The objectives of Regulatory Guide 1.68 (Revision 2, August
+
1978), Appendix A, paragraph 5.o.o are satisfied with the proposed test requirements reduction.
Previous plant startup i
results have demonstrated that the vibration and deflection measurements during recirculation pump trips and restarts are well below prescribed limits.
Therefore,~ deleting the test l
requirements for recirculation, pump trips / restarts at Hope Creek Generating Station will,>not adversely affect any safety related system or the safe operation of the plant, and as such, i
does not involve an unreviewed safety question.
Therefore, Test Number 31, Drywell Piping Vibration, can be simplified by i
deleting the test requirements for
- recirculation pump (,s(trip and restart vibration data from the Hope Creek Generacing-
]
Station power ascension test program.,
f s
p-k 1
'{
\\
i t
t-
\\
\\,
I 4
j 6
\\
f d
k h
4,1,
\\
I v
I 1
4 4
1 f
k I
4 i
1
I GEEERAL ELECTRIC COMPAE4Y TECHMICAL ANALYSIS I
HOPE CREEK GENERATING STATIOli g
t TEST NUMBER 32 - REACTOR WATER CLEANUP SYSTEM TEST SIMPLIFICATION - REDUCED NUMBER OF TESTS OBJECTIVE:
Regulatory Guide 1.68 (Revision 2, August 1978), Appendix A, paragraph 4.r requires the demonstration of the operability of the reactor coolant system purification and cleanup systems during low power testing.
Test Number 32, Reactor Water Cleanup System (RWCU), demonstrates the operation of the RWCU system.
Process variables will be recorded with the reactor at rated temperature and pressure during steady state operation of the RWCU in three modes: hot standby, normal and blowdown.
In addition, the pump available net positive suction head (NPSH) is determined and the bottom head drain flow calibration is verified during the hot standby mode of operation.
It is proposed to delete the RWCU non-regenerative heat exchanger (NRHX) flow test in the blowdown mode and the bottom head drain flow rate calibration.
It is also proposed to perform the RWCU NRHX flow test in the normal operating mode at Test Condition 1 and to determine RWCU pump NPSH during preoperational testing.
DISCUSSION:
Process variables will be measured and compared to acceptance criteria which define required system performance.
The criteria require that the temperature at the tube side outlet of the non-regenerative heat exchanger (NRHX) does not exceed specified limits when the RWCU is in the blowdown or normal mode of operation.
Also, the outlet temperature of the NRHX and the cooling water supply to the NRHX shall be within specified limits.
Further, the pump vibration for any mode and available NPSH during the hot standby mode shall be within specified limits.
Fin'lly, bottom head and RWCU flow indications shall agree within specified limits.
The bottom head flow rate calibration may be accomplished at any time after completion of the power ascension testing.
The purpose of the flow rate indication is to demonstrate both maximum bottom head coolant withdrawal to prevent thermal stratification when the main recirculatien pumps are idle, and to demonstrate a lower flow rate during normal withdrawal to induce some degree of crud removal from the bottom of the reactor.
The flow rate calibration is not required for system safety or operation.
It is needed only to demonstrate that with all lines open there is a substantive increase in flow, and is needed with only moderate accuracy because it is redundant to system flow measuring.
1
e l
l The RWCU flow test for the NRHX does not need to be performed in the blowdown mode.
Temperature and flow measurenenta taken with the RWCU operating in its normal mode may be obtained to show the heat exchange capability of the units.
From these data, the performance of the heat exchangers in the blowdown mode of operation can be demonstrated to be within the limits of flow and temperature imposed by the design.
Also, the RWCU flow test for the NRHX can be performed at Test Condition 1 rather than at Test Condition Heatup.
Test Condition 1 is a i
more representative plant operating condition because with the turbine-generator synchronized to the grid feedvater heating will be in service.
Determination of the pump available NPSH can be performed at any time during preoperational or startup testing.
Calculations performed to determine the NPSH at the limiting conditions based on the cold test data can demonstrate compliance with the acceptance criteria.
CONCLUSION:
The RWCU is not important to safety and performance statistics do not form a basis for safe reactor operations.
The NRHX flow s
rate limits are physical limitations checked by tho manufacturer and verified during the normal operating mode test.
Testing of the pump available NPSH at cold conditions and performing calculations to determine the NPSH at limiting conditions based on the cold test data satisfy the objective of Tes t Number 3 2.
The bottom head flow indication does not impact upon any safety conditions and can be performed following the power ascension test program.
The proposed changes will not adversely affect any safety systems or the safe operation of the plant and as such do not involve an unreviewed safety question.
Regulatory Guide 1.68, Appendix A, paragraph 4.r objectives are still met with the remaining RWCU testing.
Therefore, Test Number 32, RWCU, may be simplified by deleting the NRHX flow test in the blowdown mode and by performing it in the normal operating node at Test Condition 1, s
by postponing the bottom head flow rate calibration until after completion of power ascension testing, and by performing the NPSH test at convenient conditions.
l 1
2
_ _ - _ _ _ _ _ _ _ _ _ _ _