ML19294A508
| ML19294A508 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 11/29/1978 |
| From: | Bixel D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| TASK-06-06, TASK-6-6, TASK-RR NUDOCS 7812070215 | |
| Download: ML19294A508 (3) | |
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.....,..co.on m.::.o November 29, 191d Mr James G Keppler Office of Inspection and Enforcement Region III US Nuclear Regulatory Co _.ission 799 Roosevelt Road Glen Ellyn, IL 60137 DOCKET 50-155 - LICENSE DPR BIG ROCK POINT PLJIT -
SCHEDULE FOR PEFFORMANCE OF REACTOR CCNTAImCIT INTEGRATED LEAK RATE TEST The purpose of this letter is to docu=ent a Nove=ber 20, 1978 telephone conversation with D Runter of your staff.
In this conversation, the schedule for performing the next Big Rock Point containment integrated leak rate test was discussed. The next test is scheduled for late 1980 or early 1981 as discussed in Appendix 3 to Special Repert No 27, " Reactor Contain=ent Building Integrated Leak Rate Test," which was submitted to the Director of Nuclear Reactor Regulation on Februa:/ 3,1978. A copy of this appendix is attached for your convenience.
Mr Hunter stated that the schedule identified in the attached appendix had been discussed within your staff and that it had been agreed that this schedule was in confor ance with 10 CFR 50, Appendix J, and the Big Rock Point Technical Specifications.
David A Bixel (Signed)
David A Bixel Nuclear Licensing Administrator CC:
Lirector, Office of ;Iuclear Reactor Regulation Director, Office of Inspection and Enforcement h
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17 Special Report ITo.
27 Reactor Contaic=ent Building Integrated Leak Rate Test APPETDIX 3 TECETICAL JUSTIyICATION FOR NEXT SCHEDULED ILRT BEING IN 1950-1981 a
The purpose of this analysis is to provide technical justi'fication for the next proposed contain=ent integrated leakage rate test. The proposed date is about 3-1/2 years after the Septe=ber, 1977, ILRT, which is late 1980 or early 1981. The basig for this analysis is 10CFR50, Appendix J and the last two contain=ent ILRTs results (197h and 1977).
In Section A.6.b of Appendix J, it states :
"If two consecutive periodic type A tests fail to =cet the applicable acceptance criteria in III-A.5 (b), not with-standidg the periodic retest schedule of III.D,a Type A test shall be perfor=ed at each plant shutdown for refueling or approxi=stely 18 =cnths" n0TE:
III.A.S.b is: Acceptance criteria - (1) Reduc, pressure testc. The leakage rate Lt= shall te less than 0.75 Lt. If local leakage -easuve=ents are taken to effect repairs in order'to =eet
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.the acceptance criteria, these =easure=ents shall be taken at a test pressure Pt.
(2) Peak pressure tests. The leakage rate
- La= shall be less than 0.75 La.
If local leakage =easure=ents are taken to effect repairs in order to =eet the acceptance criteria, these =casure=ents shall be taken at a test pressure Pa.
AND J.22.D is:
Periodic retest schedule - 1.
Type A test.
(a) After the preoperational leakage rate tests, a set of three Type A tests shall be perfor=ed at appro
- ately equal intervals during each 10-year service pericd. The third test of each set shall be conducted when the plant is shutdown for the 10-year plant in-service inspections.
(b) Per=issible periods for testing. The perfor=ance of ?ype A tests shall be li=ited to periods when the plant facility is non-operational and secured in the shutdown condition under the ad=inistrative control and in accordance with the safety procedures defined in the license.
18, a
Special Report No. 27 Reactor Contai=ent Building Integrated Leak Rate Test Appendix 3 (.contd) m i
During the last two contai=ent leak rate tests, the excessive leakage rates encountered vere due to a single conponent (1974 - supply ventilation butter-fly valve; 1977 - feedvater check valve) which was.th' n repaired and test e
results proven acceptable.
s In the 1974 ILRT, a leakage rate of.3095/ day was experienced during the first hold test. This leakage rate is almost double the Technical Specification limit of.175%/ day. Quoting fro = page k and 5 of the 197h ILRT Report:
"Upon investigation for the source of the high ceasured leakage rate, it was discovered that the 2k-inch butterfly valve on the supply ventilation line into the contai=ent building was leak-ing at the contai=ent-side flange. This valve had been installed during the shutdown prior to conducting the leak" rate test. An esti= ate of the leakage rate was made by colli =ating the air flow through a one-inch dia=eter (I.D. ) pipe and =easuring the velocity profile across the pipe. The leakage rate through the flange was esti=ated to be 0.2925/ day. Hence, essentially all of the leakage
=casured during the first hold test was through the supply vent butterfly valve contain=ent side flange.
Bolts were tightened around the flange and the'l:eiakage stopped.
The contai=ent pressure was increased to approx?,=ately 8 inches of H,0 above the reference syste= and conditions. vere allowed to j
stabIlice for four hours prior to initiation of the second holi test."
This po-tion of the 197h test report related the fact that the 24-inch supply ventilition butterfly valve contai=ent side flange vas leaking through at the rate which was observed in the first hold test. Thus, by tighteni=g dovn on the bolts around the flange, the leakage stopped. (Hote the resultant contai=ent leakage rate of.0755/ day was still within the
.75 L 14-4 t. ) The valve had been installed during the sa=e outage the inte-grated l d ze rate test was perfor=ed. The ILRT essentially acted as an in-sta11ation acceptance test for the valve, especially the contai=ent side flange.
The 1977 co= tai =ent integrated leak rate test was the first contai=ent test that was in full ec=pliance with ICCyR50, Appendix J.
Draining and venting of several syste=s to atte=pt a close approximation of syste= status after an accident was perfor=ed in preparation for the test. The feedvater syste= vas one syste= in which a leakage path was found.
The. les.hge path was through two feedvater check valves. The feedvcter syste=
vas then isolated and after the co=pletion of the test, the leakage rate through the check valve was deter =ined, utilicing the pressuriced contai=ent as a source of air. The check valve leakage was measured with a gas flov =eter attached to the feedvater line to obtain the magnitude of the leakage.
The feedvater line leakage path was detected approx 1=ately half vay through the controlled leakoff portion of the ILRT. Exa=1 nation of *est results at that ti=e indicated a leakage r ste greater than expected in the controlled leakoff portion.
19 s
Special Report :To.
27 Reactor Contain=ent Building Integrated Leak Rate Test Appendix 3 (contd) m In turn, investigation of the leakage resulted in the conclusion that the feed-water check valve was leaking through. The feedvater line was then isolated.
Thus, the initial hold test was considered invalid and corrective actica was taken to continue with the contain=ent testing.
In conclusion, as a result of the excessive leakage rate enecuntered, due to the feed'.ater check valves, and the evidence presented above, this ILRT is considered to be the first ILRT failure. Thus, if the ILRT in 1980-81 re-sults in unacceptable results, then III.A.6(b) applies.
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