ML20057A257
| ML20057A257 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 08/30/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20057A256 | List: |
| References | |
| NUDOCS 9309130287 | |
| Download: ML20057A257 (6) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION n
3 WASHINGTON, D. C. 20555
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SAFETY EVAL,UATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AN EXEMPTION FROM 10 CFR PART 50. APPENDIX J REOUIREMENTS FOR CONTAINMENT LEAK RATE TESTING PHILADELPHIA ELECTRIC COMPANY PUBLIC SERVICE ELECTRIC AND GAS COMPANY DELMARVA POWER AND LIGHT COMPANY ATLANTIC CITY ELECTRIC COMPANY PEACH BOTTOM ATOMIC POWER STATION. UNIT 3 DOCKET NO. 50-278
1.0 INTRODUCTION
By letter dated June 11, 1993, and supplemented by letter dated July 26, 1993, Philadelphia Electric Company (PEco, the licensee) requested a one-time schedular exemption from the requirements of 10 CFR Part 50, Appendix J, Sections III.D.2(a) and III.D.3. The temporary schedular exemption would extend the interval for Type B and C local leak rate tests (LLRT) for certain Peach Bottom Atomic Power Station, Unit 3 (Unit 3) containment penetrations for 60 days beyond the requirements of 10 CFR Part 50, Appendix J.
The affected penetrations and valves or boundaries are listed in Table 1 and Table 2.
Appendix J requires that these tests be performed at every refueling outage, but with the interval not to exceed 2 years.
PECo performed LLRTs on the affected penetrations between September 15, 1991 and October 27, 1991 during refueling outage 3R08. The Peach Bottom Atomic Power Station units are currently operating on a 24-month refueling outage schedule; the next Unit 3 refueling outage, 3R09, is scheduled to commence no later than September 18, 1993.
The licensee divided the affected penetrations into two groups: 1) those that require shutdown reactor conditions but fall due prior to the scheduled commencement of 3R09 on September 18,1993 (see attached Table 1), and 2) those that require reactor shutdown conditions and fall due after the scheduled commencement of 3R09 (see attached Table 2).
The licensee presented information to justify an LLRT extension for thens two groups.
The staff's evaluation of the licensee's justification is provided below.
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2.0 EVALUATION l
2.1 Need For Extendino The Test Interval By 60 D as The licensee has stated tnat those components in Table I cannot be tested at power for two reasons. Maay of the Table 1 penetrations require access to the drywell in order to conduct the tests. The drywell is inaccessible during power operations.
Certain penetrations of those listed in Table I require safety systems to be isolated which is unadvisable during power operation.
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Therefore, a shutdown would be required in order to completely test all of the affected penetrations.
The licensee presented a description of the special circumstances that would result in hardship or other costs significantly in excess of those contemplated when Appendix J was adopted.
The licensee has adopted improved l
technology reactor fuel which allows operation on a 24-month operating cycle.
l Performance of the affected penetration leak tests within the strict 24-month requirements of Appendix J would require an extended or early plant shutdown.
Granting of the exemption would allow operation for the 4 remaining days in the planned operating cycle.
In addition, the requested 60-day exemption would allow flexibility when scheduling the perfo mance of the affected LLRT (both Table 1 and Table 2 penetrations) during the outage.
PEco stated that 1
little or no safety benefit would result from an early extended shutdown for the purpose of performing the affected LLRTs.
2.2 Leak Rate Test Performance History The licensee prese.'ted information in support of their request for a 60-day extension of the Type B and C test intervals. The maximum allowable leakage rate for maintaining primary containment (L - minimum pathway leakage) is 125,417 cc/ min for Unit 3.
Theas-foundtolalTypeBandCminimumpathway leakage rate observed during Unit 3 refueling outage 3R08 during the fall of 1991 was 35,197 cc/ min.
The as-left leak rate for that same outage was 24,453 cc/ min. The licensee stated that an extension of the leak test interval to allow for 4 days of operation is not likely to decrease the margin between as-found leak rates and L,.
PEco also stated that the remainder of the total 60-day extension, requested for outage planning flexibility, will have minimal safety significance since the unit will be in cold shutdown.
Primary containment integrity is not required during cold shutdown.
The staff reviewed the leak rate information presented by the licensee and concurs that an additional 4 days of operation at power will not significantly decrease the margin between the expected as-found leak rates and the maximum allowable total leak rate L provides reasonable flexibil. The balance of the requested 60-day exemption ity for test planning under condition in which primary containment integrity will not be required.
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i 4 2.3 Intent of Appendix J The staff notes that the 2-year interval requirement for Type B and C components is intended to be often enough to prevent significant deterioration from occurring and long enough to permit the tests to be performed during plant outages.
Leak rate testing of the penetrations during plant shutdown is preferable because of the lower radiation exposures to the plant personnel.
Moreover, as noted before, some penetrations cannot be tested at power.
For penetrations that cannot be tested during power operation, or for which testing at power is inadvisable as discussed above, the increase in confidence in containment integrity following a successful test is not significant enough to justify a plant shutdown specifically to perform the tests so close to the end of the 2-year time period.
3.0 CONCLUSION
Based on the above evaluation, the staff finds that the requested temporary exemption, to allow the Type B and C tests intervals for those penetrations listed in Table I and Table 2 to be extended 60 days from their current expiration date, to be acceptable.
Principal Contributor:
J. Shea Date: August 30, 1993 I
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TABLE 1 LEAK TESTS EXPIRING PRIOR TO SEPTEMBER 18. 1993 EXPIRATION OF PENETRATION CURRENT LEAK NUMBERS RATE TEST AFFECTED VALVE NUMBERS N-22 9/14/93 "A"
INST TO D/W A0 3969A, CHK333202A i
N-1028, D 9/14/93 D/W Breathing Air HV E5476, HV E5007 1
N-7C 9/16/93 MSIV A0 80C, A0 86C N-38 9/16/93 Control Rod Drive System j
CV 32A, 328, 35A, 35B CV 33, 36 i
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N-210A, 211A 9/16/93 Torus Cooling and Spray MO 34B, 38B, 39B N-39A 9/16/93 RHR System MO 31B N-8 9/17/93 Main Steam Drain l
MO 74, 77
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N-57 9/17/93 Main Steam Sample A0 316, 317 N-41 9/17/93 Recirculation Sample A0 39, 40 N-4 9/17/93 Drywell Head Access i
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TABLE 2 LEAK TESTS EXPTRING ON OR AFTER SEPTEMBER 18. 1993 i
i EXPIRATION OF i
PENETRATION CURRENT LEAK NUMBERS RATE TEST AFFECTED VALVE NUMBERS i
l N-110 A-H 9/18/93 RPV STABILIZER MANWAYS i
i N-25 9/18/93 Drywell Purge Supplies A0 3505, 3519, 3520 l
j A0 3521A, 3521B-N-25 9/18/93 "0"-Rings A0 3519, 3505, 3520 N-205B 9/18/93 "0"-Rings I
i A0 3521A, 3521B i
N-13A 9/18/93 RHR System M0-258, A0-46B, A0-163B j
N-217B 9/18/93 RCIC Vacuum Relief 1
M0-5244 N-206A, B 9/18/93 Torus Level Indication N-17 9/19/93 Head Spray Blank Flange i
j M0-32, M0-33 N-225 9/19/93 RCIC Suction j
M0-13-39, MO-13-41 i
N-218A 9/19/93 "B" Instrument Nitrogen to i
Drywell and Torus Vacuum Bkr N-18 9/19/93 Drywell Floor Drain Sump A0-82, 50-83 i
N-23, 24 9/19/93 RBCCW Drywell Isolation MO 2374, M0 2373 N-21 9/19/93 Drywell Service Air Manifold HV 30165, 30163 N-225 9/20/93 Torus Clean Up M0-71, M0-70 j
1 N-19 9/20/93 Drywell Floor Drain Sump A0-94, A0-95 i
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TABLE 2 (cont.)
LEAK TESTS EXPIRING ON OR AFTER SEPTEMBER 18. 1993 EXPIRATION OF i
PENETRATION CURRENT LEAK NUMBERS RATE TEST AFFECTED VALVE NUMBERS N-227 9/20/93 HPCI M0-23-57, M0-23-58 N-214 9/20/93 HPCI Stop Check "0"-Ring CHK-12 i
N-II,12,13A, 9/21/93 Expansion Joints N-14,16A,17 N-7 A-D, N-9A, 9/23/93 Expansion Joints N-9B N-12 10/26/93 Shutdown Cooling MD-10-17, 10-18 N-16A 10/10/93 Core Spray HV-14-14, CHK-1413B l
A0-14-15B, MD-14-12B N-39A 10/04/93 Containment Spray H0-26B, M0-318 N-9A 9/26/93 Feedwater System M0-29A, 6-28A 6-96A, M0-38A M0-2319 N-9B 9/25/93, 9/26/93 Feedwater System M0-29B, 6-28B M0-38B M0-1321, MO-1268 N-52F 9/19/93 "B" Instrument N to DW 2
A0-39698, HV-33310, CHK-33202B, CHK-33312
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