ML20199K513
| ML20199K513 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 06/23/1986 |
| From: | Ainger K COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 1799K, NUDOCS 8607090176 | |
| Download: ML20199K513 (16) | |
Text
['
Commonwealth Edison k.,, ! 72 West Ad.'ms Street, Chictgo, Illinois Address Reply to: Post Office Box 767
\\
Chicago, Illinois 60690-0767 C
June 23, 1986 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
Byron Station Unit 2 Braidwood Station Units 1 and 2 Startup Test program NRC Docket Nos. 50-455, 50-456 and 50-457
Dear Mr. Denton:
This letter provides an advance copy of FSAR revisions concerning the Startup Test Program described in Chapter 14 of the Byron /Braidwood FSAR.
These revisions modify or eliminate certain tests from the startup test program for Byron Unit 2 and Braidwood.
The proposed changes are based on our comprehensive review of the startup test program completed on Byron Unit 1.
This review was undertaken to identify lessons learned that would improve the startup program and make it more efficient for the remaining three units. Our review has concluded that one test should be modified and five others should be eliminated.
The startup test regarding rod drop measurements is being modified so it will only be performed at hot, full flow conditions in the reactor coolant system. Additionally, the following five tests which were performed on Byron Unit 1 are being eliminated from the startup test program for Byron Unit 2 and Braidwood.
- pseudo Rod Ejection l
- Shutdown From Outside the Control Room
- Flux Asymmetry Evaluation
- Turbine Trip from 25% power Revisions to the FSAR Chapter 14 test abstracts and reasons for the proposed changes are contained in Attachment A to this letter.
8607090176 860623 PDR ADOCK 0500 5
A 0 0' TO EE &
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Mr. H. R. Denton June 23, 1986 We are requesting NRC concurrence with these proposed changes to the startup test program for Byron Unit 2 and Braidwood. The attached FSAR revisions will be included in the next FSAR amendment. Appropriate revisions to FSAR Appendix A1.68 will also be included.
Please direct any questions regarding this matter to this office.
One signed original and fifteen ccpies of this letter and attachment are provided for NRC review.
Very truly yours, K. A. Ainger Nuclear Licensing Administrator im Attachment cc: Byron Resident Inspector Braidwood Resident Inspector
)
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ATTAQWENT A i
4 REVISIONS TO STARTUP TEST PROGRAM BYRON UNIT 2 AND BRAIDWOOD UNITS 1 AND 2 1.
Rod Drcp Measurements 2.
Pseudo Rod Ejection 3.
Shutdown From Outside the Control Room 4.
Flux Asymmetry Evaluation 5.
Turbine Trip from 25% Power i
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1.
Rod Drop Measurements FSAR Table 14.2-66 has been modified to indicate it applies to Byron Unit 1 only. A new table has been generated for Byron Unit 2 and Braidwood Units 1 and 2 (Table 14.2-66a).
This is a modified version of Table 14.2-66 that requires rod drop measurements only at hot, full-flow conditions in the reactor coolant system (RCS).
A full spectrum of rod drop measurements was made for Byron Unit 1 at cold, no-flow, hot, no-flow, cold, full-flow, and hot, full-flow conditions. Byron Unit 2 and Braidwood Units 1 and 2 are identical to Byron Unit 1 with respect to the rod control system. Because of this, no additional design information would be obtained by repeating the entire spectrum of rod drop measurements that was originally done for Byron Unit 1.
Consequently, it is proposed to perform the hot, full-flow measurements for the remaining three units for the purpose of providing a satisfactory baseline for required Technical Specification surveillances.
Westinghouse confirmed that rod drop time acceptance criteria for FSAR and Tech Spec considerations are applicable only with the RCS at hot, full-flow conditions. Based on past experience, rod drop times at other test conditions fall under the hot, full-flow values.
It is therefore conservative to measure the rod drop times at the hot, full-flow condition.
3 Revisions to PSAR Appendix A1.68, reflecting the discussion above, will be made in the next emendment. Revised Table 14.2-66 and new Table 14.2-66a are attached.
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TABLE 14.2-66 ROD DROP MEASUREMENTS Byron Unit l (Startup Test)
Plant Condition or Prerequisites Core loading has been completed and prior to initial crit-icality with various RCS temperatures, pressures and flow condition.
. Test Objective To measure rod drop times at cold no-flow, cold full-flow, hot no-flow, and hot full-flow plant conditions following core loading.
Test Summary The drop time for each control rod will be measured at cold no-flow, cold full-flow, hot no-flow, and hot full-flow conditions.
All rods falling outside the two-sigma limit will be retested a minimum of three additional times each.
The drop time will be measured from the decay of the station-ary gripper coil voltage until the rod enters the top of the dashpot.
The RCCA drop traces will confirm proper oper-ation of the decelerating devices.
Acceptance Criteria The rod drop time is verified to be less than the maximum value specified in Subsection 3.9.4.3.
4 14.2-78
o B/B-FSAR TABLE 14.2-66a ROD DROP MEASUREMENTS Byron Unif 2 ; Scaiducoci Unds I and 2-(Startup Test)
Plant Condition or Prerequisites Core loading has been completed and prior to initial crit-icality with sjpespam RCS temperature $, pressure ( and flow condition s.
,4,, ne,7,ger,4;,5
_ Test Obiective To measure rod drop times at co1%W#NE-A.
NM mFrimurFr dE hot, full-flow plant conditions following e
core loading.
Test Summary The drop time for each control rod will be measured at M iwCNM-Fe w n=fl
- _ " hot, full-flow conditions.
All rods falling outside the two-sigma limit will be retested a minimum of three additional times each.
The drop time will be measured from the decay of the station-ary gripper coil voltage until the rod enters the top of the dashpot.
The RCCA drop traces will confirm proper oper-ation of the decelerating devices.
Acceptance Criteria The rod drop time is verified to be less than the maximum value specified in Subsection 3.9.4.3.
i 14.2-78a l
2.
Pseudo Rod Biection FSAR Table 14.2-81 has been modified to indicate it applies only to Byron Unit 1.
The results of the Byron Unit 1 pseudo rod ejection test confirmed the design predictions made for this event within the accuracy of the testing procedure.
Verification of core design parameters for the remaining three units can be achieved through control rod worth measurements, boron worth measurements and flux mapping at zero power and during the power ascension phase. These tests provide sufficient data to ensure that core performance will be within design criteria and in accordance with Technical Specifications. A repeat performance of the pseudo rod ejection test will provide no additional information with regard to core performance because of the design similarity.
Revisions to FSAR Appendix A1.68, reflecting the discussion above, will be included in the next amendment. Revised Table 14.2-81 is attached.
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B/B-FSAR TABLE 14.2-81 PSEUDO ROD EJECTION Byro n Unit /
(St'artup Test)
Plant Condition or Prerequisites Reac tor. is critical with the neutron flux level in the zero power physics testing range.
RCS temperature and pressure are at hot no-load values.
Testing will be repeated at 306 reactor power.
Test Objective i
To verify hot channel factors and rod worth with a rod cluster control assembly (RCCA) withdrawn from its bank position.
Test Summary Incore measurements will be made with the most reactive RCCA withdrawn from its bank position to determine the resulting hot channel factors.
The worth of the most reactive RCCA will be verified to be conservative with respect to the accident l
analysis.
Measurements will be made using the incore flux l
monitoring system.
Tests will be run at hot zero power and at approximately 30% reactor power.
Acceptable Criteria T
l F
hot channel factors and rod worths are less than the vElues given in Table 15.4-3.
4 idef e :
Pe r for son c e. e f Me. 7seudo red ejection 4es.t o n Byron Unit l provides Mc nece ssary desig n in Orna4Ien Ac oil (cur 8 eon and Braidu>eod unif s will re3ard 4o Mrs 7
sp ecific event.
Nu c. le a r-desig n parase.f c.c5 -fo r f A c. Ares reuaining unihs will be verifie.d by addMional skr4up 4esis j
such as conhol red bank worAS, boron wor M a nd core. #Iv 3
j dis f ri bubn.
14.2-93
3.
Shutdown From Outside the control Room FSAR Table 14.2-86 has been modified to indicate it applies only to Byron Unit 1.
This test was performed on Byron Unit 1 above 10% reactor Preoperational test procedures 2.63.60 and RC-10 for Byron Unit power.
2 and Braidwood, respectively, test the remote shutdown systems. These tests require that the plant be maintained in the hot standby condition for at least 30 minutes. The only significant difference between these preoperational tests and the existing startup test is that, during the startup test, there is fuel in the reactor and it is at power. This does not affect demonstration of the remote systems capability to maintain the plant at hot standby or proceed to cold shutdown. Our conclusion is that all necessary design information regarding remote shutdown capability is obtained during the preoperational test program and this startup test is not needed for the remaining three units.
Revieions to FSAR Appendix A1.68, reflecting the discussion above, will be included in the next amendment. Revised Table 14.2-86 is attached.
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B/B-FSAR TABLE 14.2-86 SHUTDOWN FROM OUTSIDE THE CONTROL ROOM Syron Uni + l l
(Startup Test)
Plant Condition or Prerequisites Above 10% reactor power.
Test Objective To demonstrate that the plant can be maintained in hot standby from outside the control room.
Test Summary Data will be obtained at locations outside the control room to verify that the plant has achieved hot standby status and that the plant can be maintained at stable hot standby conditions l
for at least 30 minutes.
Also, data will be obtained at loca-tions outside of the control room to demonstrate a potential i
capability for cold shutdown by partially cooling down the j
plant from the hot standby condition.
Acceptance Criteria Data obtained from outside the control room demonstrates:
1.
The plant is tripped and in a stable hot standby condition for at least 30 minutes.
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2.
The potential for cold shutdown from the hot standby condition:
a.
Reactor coolant temperature and pressure can be lowered to permit operation of the core decay heat removal system.
b.
Operation of the decay heat removal system can be initiated and controlled.
c.
A heat transfer path to the ultimate heat sink can be established.
d.
Reactor coolant temperature can be reduced approximately 50' F using the decay heat removal system at a rate in accordance with the Technical Specifications, Chapter 16.0.
Note:
Tbe. s/SleA5 clesign oncl inlegradion is verj[ied by fliig fcgf On 0 ron Unib l.
l~or 4hc subsepent-Orsa uni 45, fhe. individ u l skuld)'own 5f 5fe4s art desfe.d and M6 controls cufside M. conhof huschonally Veri {ie d.
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4.
Flux Asymmetry Evaluation I
FSAR Table 14.2-84 has been modified to indicate it only applies to Byron Unit 1.
Design confirmation obtained from the Byron Unit 1 test for this measurement applies to the remaining three units which have identical core configurations and system design. Other tests which measure control rod worth, boron worth, reactivity coefficients, and core flux distribution maps will provide verification of proper core loading and overall design for each of the three remaining units. No new information is gained by repeating this test for the other units.
Data evaluated from the Byron Unit 1 test was as expected and acceptable.
Revised Table 14.2-84 is attached.
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l TABLE 14.2-84 FLUX ASYMMETRY EVALUATION Syron Uni}- l (Startup Test)
Plant Condition or Prerequisites Reactor power at approximately 50% power.
Test Objective To verify that core performance margins ar'e within the plant Technical Specification limits as an RCCA is inserted into the core from its normal bank position, and to determine the response of excore nuclear detectors under asymmetric 1
power distributions.
l Test Summary A pseudo rod drop test will be performed at approximately 50% reactor power.
A slow RCS dilution will be performed with the selected RCCA stepped fully into the core.
Acceptance Criteria The DNBR will be demonstrated to be in accordance with Subsection 4.4.1.1.
This ksling s ruforsed only on Byron Unif I. The Nofe:
i clesign con firaaf to n obtained Gom this fest will apply 40 +he o%er 4 hr<e Byron and Bralckcod un;&s wUek inve. Idensical I
designs.
14.2-96
5.
Loss of Offsite Power FSAR Table 14.2-87 has been modified to indicate it applies to Byron Unit 1 only.
A loss of offsite power test was performed successfully on Byron Unit I during the startup test program. The purpose of the test was to verify that onsite AC power systems will function to supply power to critical systems necessary for safe shutdown without any source of offsite power. Onsite AC power system components are tested during the pre-operational test program. During the preoperational test program, the onsite power systems can be verified to be functional without imposing a transient burden on the plant. Because the integrated onsite power system was demonstrated to function properly on Byron Unit 1 and no new design information will be obtained, it is prudent to take advantage of the standardized design of the Byron /Braidwood systems and the standardized recovery procedures for this event. This test is not needed for the other three units.
Revisions to PSAR Appendix A1.68, reflecting the discussion above, will be included in the next amendment. Revised Table 14.2-87 is attached.
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B/B-FSAR TABLE 14.2-87 LOSS OF OFFSITE POWER Byron L4niF I (Startup Test) l Plant Condition or Prerequisites Above 10% reactor power with offsite power unavailable and emergency diesels available.
Test Objective To demonstrate starting of emergency diesels, stripping of vital buses, and sequencing loads on vital buses following a trip of the plant without an available offsite source of power.
l Test Summary I
At above 10% power, a generator trip will be initiated without an offsite source of power being available.. Starting of the emergency diesels, stripping of vital buses, and sequencing j
of emergency loads on the vital buses will be demonstrated.
The test will be of sufficient duration to ensure that the necessary equipment, controls and indication are available following the blackout to remove decay heat from the core using only emergency power supplies.
Acceptance Criteria The plant is shown to respond to a plant trip concurrent with loss of offaite power in accordance with Subsection 8.3.1.1.1.
I The duration of the blackout will be at least 30 minutes.
l Nole: This les+ is per$rned only on Syron Un;+ 1.
OnsWe A C-l pow e.r-is fes4ed for fhe olhe th re e. uni ts a nd +4e speci fic.
recovery ywceduces frw Byron Uni & I wilI be used a+ #e-oiker +hree unifs.
Furner 4es4;$ of 4k;s na4are. on +Ae ofhe j
unRs iuposes an un necessa ry +rons;ed 6urcien.
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l 14.2-99
r 6.
Turbine Trip from 25% Power FSAR Table 14.2-91 has been modified to indicated it applies only to Byron Unit 1.
A turbine trip from 20% power was performed on Byron Unit I to demonstrate adequate design of the primary and secondary systems to sustain this trip without the condenser bypass system available. The results of this test were as expected and acceptable. All information required to verify the system design for the Byron /Braidwood units was obtained during this test. A turbine trip from 100% power is planned for all units. This is a more severe transient than the trip from 25%
power. No additional information from a 25% power turbine trip is necessary for design confirmation.
Revised FSAR Table 14.2-91 is attached.
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TABLE 14.2-91 hron Unid /
TURBINE TRIP FROM 25% POWER (Startup Test)
Plant Condition or Prerequisites
~
Plant at 254 + 34 of normal steady-state full power condition with the auxiliary electrical loads supplied from the unit
.I auxiliary transformer.
Test Objective i
To verify the ability of the primary and secondary plant and the plant automatic control systems to sustain a trip from 254 power without the turbine bypass to condenser system avail-able, and to bring the plant to a stable condition following the transient.
Test Summary j
The plant will be brought to normal 254 steady-state power conditions with the auxiliary loads supplied from the unit auxiliary transformer.
The plant will be tripped by manually tripping the turbine from the turbine control station.
The parameters to be monitored will include nuclear flux; reactor coolant loop temperature; pressurizer pressure and j
level; steam generator level, s. team flow, and feed flow; turbine trip operation; reactor trip breaker operation; and controlling group rod position indication.
The parameters will be selected to determine the response of the plant control systems.
Acceptance Criteria The acceptance criteria that must be met to successfully complete the turbine test are:
The pressurizer safety valves shall not lift; a.
b.
The pressurizer power-operated relief valves shall not lift; The steam generator power-operated valves shall operate c.
as designed to remove energy; d.
Safety injection shall not be initiated; and, No unacceptable water hamqer in the steam generators e.
and/or feedwater system shall occur.
Note.: This design veti$calion f egf is run onlyl$ bu-Byron Lf I. de on Speci[ic. LopfontedS and SfShe in ad Wi indIb duullf htSY'Y on su b s e ftwenf u n # +S-