ML20137G303
| ML20137G303 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 08/20/1985 |
| From: | DUKE POWER CO. |
| To: | |
| Shared Package | |
| ML20137G280 | List: |
| References | |
| NUDOCS 8508270259 | |
| Download: ML20137G303 (4) | |
Text
c Attachmtnt I CONTAINMENT SYSTEMS CONTAINMENT LEAKAGE LIMITING CONDITION FOR OPERATION 3.6.1.2 Containment leakage rates shall be limited to:
a.
An overall integrated leakage rate of:
1)
Less than~or equal to L, 0.30% by weight of the containment
(
air per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at P,,,14.8 psig, or 2)
Less than or equal to L, 0.21% by weight of the containment
(
air per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at a rbduced pressure of P, 7.4 psig.
t b.
A combined leakage rate of less than 0.60 L for all penetrations andvalvessubjecttoTypeBandCtests,whenpressurizedtoP,,
and Acombinedbypassleakagerateoflessthan0.07L) containment c.
for all penetrations identified in Table 3.6-1 as secondar bypass leakage paths when pressurized to P
- a APPLICABILITY: MODES 1, 2, 3, and 4.
ACTION:
With (a) the measured overall integrated containment leakage rate exceeding 0.75 L or 0.75 L as applicable, or (b) the measured combined leakage rate foralipenetratibn,sandvalvessubjecttoTypesBandCtestsexceeding0.60 L
or (c) the combined bypass leakage rate exceeding 0.07 L, restore the o$e,rallintegratedleakageratetolessthan0.75L or less than or equal to a
0.75L,asapplicable,andthecombinedleakagerafeforallpenetrations andvafvessubjecttoTypeBandCteststolessthan0.60L and the combinedbypassleakageratetolessthan0.07L,priorto18c,reasingthe Reactor Coolant System temperature above 200*F.
SURVEILLANCE REQUIREMENTS 4.6.1.2 The containment leakage rates shall be demonstrated at the following test schedule and shall be determined in conformance with the criteria specified in Appendix J of 10 CFR 50 using the methods and provisions of ANSI N45.4-1972 or the mass plot method:
8508270259 850820 PDR ADOCK 05000369 P
PDR Amendraent No. (Unit 2)
McGUIRE - UNITS 1 and 2 3/4 6-2 Amendment No. (Unit 1)
a Attachment II JUSTIFICATION AND SAFETY ANALYSIS The proposed amendment of Technical Specification 3.6.1.2 is necessitated by recent results of the McGuire Unit I containment integrated leak rate testing.
The containment building integrated leak rate test (ILRT) results show a lack of adequate margin between the measured value of La, 0.144% per day and the t acceptance criteria of 0.15% per day. The potential exists for exceeding the (acceptance criteria value of 0.15% per day with accompanying adverse impact on, unit reliability.
The proposed amendment of Technical Specification 3.6.1.2 would permit an overall integrated leakage rate of La = 0.30% by weight of the containment air per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> at pressure Pa = 14.8 psig.
It is the intention of Duke Power Company to demonstrate that increasing the overall integrated leakage rate La to 0.30% per day would not result in significantly different offsite or control room operator design basis calculated doses.
Duke Power Company has recently performed a new design basis dose calculation by implementing the revised Standard Review Plan (SRP) methodology (Section 6.5.2).
This revision permits credit for iodine removal by containment sprays.
Our analysis establishes that a 50% increase in the leakage rate La, from 0.20%
to 0.307., is very nearly offset by the spray removal credit. Since the noble gases are un'ffected by containment sprays the increased leakage results in a
increased whole body and skin doses. However, for McGuire Nuclear Station the thyroid radiation exposure is the limiting criteria, and the whole body and skin doses are still well within 10 CFR 100,11 and GDC 19 values.
- Below, a _ tabular comparison of LOCA doses is provided for the current and the revised calculations for the control room and the site boundary.
McGuire Control Room Operator LOCA Doses (Rem)
Whole Body Thyroid
- Skin, Current Calculation 0.22 26 4.1 Revised Calculation 0.32 19 6.1 i
)
CDC 19 Values 5.0 30.0 30.0 i
i
McGuire Offsite Design Basis LOCA Doses (Rem)
Exclusion Area Boundary Low Population Zone Whole Body Thyroid Whole Body Thyroid Current Calculation 2.97 198
.623 65.1 Revised Calculation 4.13 208
.727 50.5 10 CFR Part 100 Values 25 300 25 300 Since the LOCA doses resulting from the increased integrated leak rate of 0.30% are within the 10 CFR 100 and CDC 19 values there is sufficient tech-nical justification for relaxing the containment leakage rate to La = 0.30%.
New source term aprlications would provide further technical justification which has not been assumed in these conservative calculations. For example, the chemical form of iodine post-LOCA is believed to be primarily CsI rather than 1. Containment sprays are much more effective at removing iodine in 2
particulate form rather than the assumed elemental form. The proposed amend-ments would not result in exceeding any safety limits during normal operation or design basis accident conditions.
Attachment III ANALYSIS OF SIGNIFICANT HAZARDS CONSIDERATION As required by 10 CFR 50.91 this analysis provides a determination that the proposed changes to the Technical Specifications do not involve any signifi-cant hazards consideration, as defined by 10 CFR 50.92.
The proposed relaxation of the integrated leakage rate limit has become possible as a direct consequence of allowing credit for iodine removal by the containment spray.during a LOCA by NRC. The proposed change may increase slightly the LOCA doses but the results of the change are clearly within all acceptable limits considered in the Standard Review Plan. The proposed change is the consequence of a minor refinement of a previously used calcu-lational model.
The proposed amendment would not:
1)
Involve a significant increase in the probability or consequences of an accident previously evaluated; or 2)
Create the possibility of a new or different kind of accident from any accident previously evaluated; or 3)
Involve a significant reduction in a margin of safety.
Based upon the preceding analysis, Duke Power Company concludes that the proposed amendments do not involve a significant hazards consideration.
.