ML20216D943
| ML20216D943 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 04/09/1998 |
| From: | COMMONWEALTH EDISON CO. |
| To: | |
| Shared Package | |
| ML20216D918 | List: |
| References | |
| NUDOCS 9804160036 | |
| Download: ML20216D943 (6) | |
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3/4.6 CONTAINMENT SYSTEMS 3/4.6.1 PRIMARY CONTAINMENT CONTAINMENT INTEGRITY J
LIMITING CONDITION FOR OPERATION
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3.6.1.1 Primary CONTAINMENT INTEGRITY shall be maintained.
f APPLICABILITY:
MODES 1, 2, 3, and 4.
ACTION:
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Without primary CONTAINMENT INTEGRITY, restore CONTAINMENT INTEGRITY within I hour or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
ERVEILLANCE RE0VIREMENTS i
4.6.1.1 Primary CONTAINMENT INTEGRITY shall be demonstrated:
At least once per 31 days by verifying that all penetrations
- not f
a.
capable of being closed by OPERABLE containment automatic isolation valves and required to be closed during accident conditions are r.losed by valves, blind flanges, or deactivated automatic valves secured in their positions, except as provided in Table 3.6-1 of Specification 3.6.3 or for containment isolation valves that are open under administrative controls; b.
By verifying that each containment air lock is in compliance with the requirements of Specification 3.6.1.3; and By performing containment leakage testing in accordance with c.
Regulatory Guide !.163. September 1995, and 10 CFR 50, Appendix J.
Option B.
Mod ked k cm 9p eo y c_c.[
45 StLcdv b c_,.ceg 4
- Except valves, blind flanges, and deactivated automatic valves which are 1
located inside the containment and are locked, sealed or otherwise secured' in the closed position.
These penetrations shall be verified closed during each COLD SHUTDOWN except that such verification need not be performed more often than once per 92 days.
BYRON - UNITS 1 & 2 3/4 6-1 AMENDMENT NO.,81 9804160036 980409 PDR ADOCK 05000454 P
PDR L
CONTAINMENT SYSTEMS C0NTAINMENT LEAKAGE LIMITING CON 01 TION FOR OPERATION 3.6.1.2 Containment leakage rates shall be limited to:
An overall integrated leakage rate of less than or equal to L, at a.
P,.
A combined leakage rate of less than 0.60 L for all penetrations b.
and valves subject to Type B and C tests, wben pressurized to P,.
APPLICABILITY: MODES 1, 2, 3, and 4.
ACTION:
With either the measured overall integrated containment leakage rate exceeding 0.75 L or the measured combined leakage rate for all penetrations and valves subject to Types B and C tests exceeding 0.60 L, restore the overall integratec leakage rate to less than 0.75 L, and the combined leakage rate for l
all penetrations subject to Type B and C tests to less than 0.60 L, prior to increasing the Reacter Coolant System temperature above 200*F.
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SURVE1LLANCE REOUIREMENTS 4.6.1.2 The containment leakage rates shall be demonstrated in accordance i
with Regulatory Guide 1.163, September 1995, and 10 CFR S0, Appendix J, Option B.
Type A (Overall Integrated Containment Leakage Rate) testing shall a.
be conducted in accordance with Regulatory Guide 1.163, September 1995, and 10 CFR 50, Appendix J, Option B.
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l BYRON - UNITS 1 & 2 3/4 6-2 AME.1rWENT NO.,81'
CONTAINMENT SYSTEMS SURVElllANCE RE0VIREMENTS (Continued)
The reporting requirements and frequency of Type A tests shall be in
,b.
accordance with Regulatory Guide 1.163, September 1995,, and w
10 CFR 50, Appendix J, Option B. g m~~o~d.(ied h % cpproud sdeAv 6 C
The accuracy of each Type A test shall be verified by a supplementa w,gt,;,. l c.
test conducted in accordance with Regulatory Guide 1.163, September
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1 % 5, and 10 CFR 50, Appendix J, Option 8.
Type B and C tests shall be conducted in accordance with Regulatory d.
Guide 1.163, September 1995, and 10 CFR 50, Appendix J Option B.
Air locks shall be tested and demonstrated OPERABLE by the require-e.
ments of Specification 4.6.1.3; Purge supply and exhaust isolation valves with resilient material f.
seals shall be tested and demonstrated OPERABLE by the requirements of Specification 4.6.1.7.3 or 4.6.1.7.4, as applicable; and The structural integrity of the exposed accessible interior and g.
exterior surfaces of the containment vessel, including the liner plate, shall be demonstrated during the shutdown for each Type A containment leakage rate test by a visual inspection of these surfaces. This inspection shall be performed at a frequency in accordance with Regulatory Guide 1.163, September 1995, to verify no apparent changes in appearance or other abnomal degradation.
h.
The provisions of Specification 4.0.2 are not applicable.
i BYRON - UNITS 1 & 2 3/4 6-3 AMENDMENT NO.,99
3/4.6 CONTAINMENT SYSTEMS o
BASES 3 /4. 6.1 PRIMARY CONTAINMENT 3/4.6.1.1 CONTAINMENT INTEGRITY l
Primary CONTAINMENT INTEGRITY ensures that the release of radioactive materials from the containment atmosphere will be restricted to those leakage l
paths and associated leak ratas assumed in the safety analyses.
This restriction, in conjunction with the leakage rate limitation, will limit the SITE BOUNDARY radiation dc.es to within the dose guideline values of 10 CFR Part 100 during accidea.t conditions.
3/4.6.1.2 CONTAINM NT LEAKAGE The limitations on containment leakage rates ensure that the total containment leaktge volume will not exceed the value assumed in the accident analyses at the peak accident pressure, P,.
As an added conservatism, the measured overall integrated leakage rate is further limited to less than or equal to 0.75 L, during performance of the periodic test to account for possible degradation of the containrent leakage barriers between leakage tests.
The surveillance testing for measuring leakage rates dr9e consistent with the requirements of Appendix J of 10 CFR Part 50, Option B, Regulatory Guide 1.163, September 1995, Nuclear Energy Institute document NE! 94-01, and ANSI /ANS-56.8-1994, {\\
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7 3 /4. 6.1. 3 CONTAINMENT AIR LOCKS The limitations on closure and leak rate for the containment air locks are required to meet the restrictions on CONTAINMENT INTEGRITY and containment
'i leak rate.
Surveillance testing of the air lock seals provides assurance that the overall air lock leakage will not become excessive due to seal damage during the intervals between air lock leakage tests.
3 4.6 1.4 INTEF%AL P;ESSU:E The limitations on containment internal pressure ensure that: (1) the containment structure is prevented from exceeding its design negative pressure
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differential with respect to the outside atmosphere of 0.1 psig, and (2) the containment peak pressure does not exceed the design pressure of 50 psig
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during steam line break conditions.
The maximum increase in peak pressure expected to be obtained from a cold leg double-ended break event is defined as P.
The limit of 1.0 psig for initial positive containment pressure will limit the total pressure to P,,
which is higher than the UFSAR Chapter 15 accident analysis calculated peak pressure assuming a limit of 0.3 psig for initial positive containment pressure, but is considerably less than the design pressure of 50 psig.
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BYRON - UNITS 1 & 2 B 3/4 6-1 AMENDMENT NO.97
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REVISED PAGES
[ Insert -1) l ex' cept as' modified for Unit 2. An extension for Unit 2 is allowed to perform the Type A l
test during B2RO8. Subsequent Type A test intervals for Unit 2 will be determined based on test results, in accordance with NEl 94-01.
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ATTACHMENT C EVALUATION OF SIGNIFICANT HA7sARDS CONSIDERATION Commonwealth Edison Company (Comed) proposes to revise Technical Specifications l
(TS) Surveillance Requirements 4.6.1.1.c,4.6.1.2.a,4.6.1.2.b and the Bases to allow a schedular exception to defer the test '.cyond the interval allowed in the Nuclear Energy Institute (NEI) document NEI 94-01, " Industry Guideline for Implementing l
Performance-Based Option of 10 CFR 50, Appendix J," which is endorsed by Regulatory i
Guide 1.163, " Performance Based Containment Leak Test Program" to the Fall of 1999 for Byron Unit 2.
1.
The proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
An extension, by a maximum of 10 months, of the Type A test interval does not l
involve a change to any structures, systems, or components, does not affect rea:: tor operatiens, is not an accident initiator, and does not change any existing safety analysis previously evaluated in the UFSAR. Therefore, there is no l
significant increase in the probability of an accident previously evaluated.
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Several tables of UFSAR Chapter 15 " Accident Analyses," provide containment leak rate values used in assessing the consequences of accidents discussed in this chapter. Although an extension can increase the probability that an increase in containment leakage could go undetected for a maximum of 10 months the risk l
resulting from this proposed change is inconsequential as documented in NUREG-1493," Performance-Based Containment Leakage Test Program". This i
document indicated that given the insensitivity of reactor risk to containment l
leakage rate and a small fraction ofleakage paths are detected solely by Type A l
testing, increasing the time between integrated leak rate tests is possible with minimal impact on public risk. Further, industry experience presented in this document indicated that Type A testing has had insignificant impact on uncertainties involved with containment leak rates.
1 Based on risk information presented in NUREG-1493, the proposed change does i
not increase the probability or consequences of an accident previously evaluated.
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The proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
The proposed change does not alter the plant design, systems, components, or reactor operations, only the frequency of test performance. New conditions or parameters that contribute to the initiation of accidents would not be created as a result of this proposed change. The change does not involve new equipment and existing equipment does not have to be operated in a different manner, therefore there are no new failure modes to consider.
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