ML13317A873
| ML13317A873 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 02/18/1982 |
| From: | Baskin K Southern California Edison Co |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8202220419 | |
| Download: ML13317A873 (3) | |
Text
Southern California Edison Company P. O. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD. CALIFORNIA 91770 K. P. BASKIN TLEPHONE MANAGER OF NUCLEAR ENGINEERING, February 18, (213 572-1401 SAFETY, AND LICENSING Director, Office of Nuclear Reactor Regulation Attention: D. M. Crutchfield, Chief Operating Reactors Branch No. 5 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D.C.
20555 Gentlemen:
Subject:
Docket No. 50-206 USUIARYCOMMO Safety Injecton System Modifications DN MAMEMM OR San Onofre Nuclear Generating Station Unit 1 By letter dated October 29, 1981, we submitted a tabulation of the SIS valve opening force data obtained from the nine cold flow/Ap SIS sequencing tests.
The results of the SIS valve opening forces obtained from the hot SIS tests performed on November 1 and 2, 1981 and November 23 and 24, 1981 were provided to you during telephone discussions shortly following the completion of the tests. During the first week in December, 1981, we advised you by telephone that the manifold side piston area used to calculate the SIS valve opening forces discussed above was incorrectly assumed to be 14.92 square inches.
We indicated that the correct manifold side piston area was 14.19 square inches and that the SIS valve opening forces discussed above would be increased by approximately 1500 lbs-f using the 14.19 square inches rather than tfie 14.92 square inches.
The purpose of this letter is to submit the corrected SIS valve opening forces. Accordingly, enclosed is a tabulation of the accumulator, manifold and line pressure data and the corresponding SIS valve opening forces obtained from the nine cold flow/Ap SIS sequencing tests and the hot SIS tests discussed above.
For your information, we have reviewed Amendment No. 57 to the San Onofre Unit 1 Operating License and the supporting Safety Evaluation issued by your November 5, 1981 letter which document your review and conclusions concerning the proposed program, schedule, system modifications and technical specifications related to the SIS. Based on our review, your conclusions stated therein are not invalidated; however, one item in Amendment No. 57 and one item in the supporting Safety Evaluation have changed as a result of the corrected SIS valve opening forces.
8202220419 6202129 PDR ADOCK 05000206 1
p PDR
Mr. D.
February 18, 1982 Amendment No. 57 imposed a requirement for periodic surveillance of the SIS, including reference to the average actuator force from pre-operation testing (3135 lbs-f).
This average actuator force which is based on the incorrect SIS valve opening forces submitted by our aforementioned October 29, 1981 letter would have been used as part of a straight line extrapolation to predict the time (in days) between the first and second hot SIS surveillance test. In addition, the actuator forces that will be used if the straight line extrapolation is required to predict the duration between the second and third, the third and forth and subsequent hot SIS surveillance testing are those from the previous hot SIS surveillance testing. As you know, the actuator forces from the first and second hot SIS surveillance testing did not require use of the straight line extrapolation.
Therefore, the average actuator force from preoperation testing (3135 lbs-f) based on the incorrect SIS valve opening forces which were made part of the Technical Specifications will not be used in the future and the Technical Specifications do not need to be revised.
The tabulation of the SIS valve opening force data submitted by our aforementioned October 29, 1981 letter was referenced in and made a part of (as Figure 5) the Safety Evaluation supporting Amendment *No. 57.
As discussed above, the tabulation was based on use of an incorrect manifold-side piston area.
The SIS valve opening force data has been corrected and is provided as an enclosure to this letter. Since the corrected SIS valve opening forces are below the 10,000 lbs-f, except as discussed below, assumed as a threshold indicator 'of loss of actuator margin, the conclusions documented in the Safety Evaluation are not invalidated; namely, the proposed program, schedule, system modifications and technical specifications related to the SIS are acceptable.
As indicated in the enclosed tabulation, the SIS valve opening force calculated for HV-851A during the first hot SIS surveillance test performed on November 1 and 2, 1981 was above 10,000 lbs-f. However, we advised you shortly following the completion of the tests that this valve opening force occurred when the valve body cavity vent valve was inadvertently locked closed during the test and that two additional hot SIS surveillance tests were successfully performed to verify proper operation.
If you have any questions, or desire further information concerning the discussion above, please let me know.
Very truly yours, Enclosure cc:
R. H. Engleker, Director, OTE, Region V L. Miller, Resident Inspector., San Onofre Unit 1
SIS VALVE PR1JECT SAN ONOFRE UNIT 1 OPENING FORCE DATA (COPREXCTED)
HV-851A HV-851B COLD SIS; RWST LINEUP;
+ ACCUM'R
+MAN 'D
+LINE FRCE
+ ACCUM'R
+MAN'D
+LINE FDCE PRE-INSPECrITN PSIG PSIG PSIG lbf PSIG PSIG PSIG lbf RUN NO.
1 3200 2200 350 5242 3200 2100 320 6566 2
3200 2200 335 5194 3200 2000 320 7985 3
3200 2200 350 5242 3200 2100 315 6551 4
3200 2200 350 5242 3200 2200 320 5147 5
3100 2200 350 4137 3200 2100 320 6566 6
3200 2200 350 5242 3200 2200 320 5147 7
3200 2200 320 5147 3200 2000 315 7970 8
3200 2200 335 5194 3200 2100 315 6551 9
3200 2200 335 5194 3200 2100 315 6551 AVERAGE 3189 2200 342 5093 3200 2100 318 6559 COLD SIS; IST LINEUP; POST-INSPECTION 1
3200 2200 350 5242 3200 2200 320 5147 2
3200 2300 345 3807 3200 2300 335 3775 3
3200 2300 350 3823 3200 2300 335 3775 AVERAGE 3200 2267 348
.4291 3200 2267 330 4232 HOT SIS -
11/1/81 -
11/2/81 1
3200 1700 1250 15164 3200 2200 315 5132 2
3200 2300
. 315 3713 3200 2100 330 6598 3
3200 2300 305 3681 3200 2100 315 6551 HOT SIS -
11/23/81 -
11/24/81 1
3100 2300 260 2435 3200 2100 315 6551
+Pressure values extracted from charts of test results by Startup.