ML20195D063
| ML20195D063 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 06/03/1999 |
| From: | Roche M GENERAL PUBLIC UTILITIES CORP. |
| To: | |
| Shared Package | |
| ML20195D062 | List: |
| References | |
| NUDOCS 9906090076 | |
| Download: ML20195D063 (4) | |
Text
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OPERATING LICENSE l
NO. DPR-16
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TECHNICAL SPECIFICATION CHANGE REQUEST NO. 226 DOCKET NO. 50-219 l
Applicant submits by this Technical Specification Change Request No. 226 to the Oyster Creek Nuclear Generating Station Technical Specifications, modified pages 1.0-8 and 3.3-3 through 3.3-8a,3.10-2,3.10-3,3.10-4 and 3.10-5.
By:
Michael B. Roche Vice President and Director Oyster Creek Sworn to and Subscribed before me this day of June 3, 1999.
c) dub f k' Notary Public GERALDINE E. LEVIN NOTARYW OFIEWN
& W Espins) ~ Y 'd"'N I
9906090076 990603
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PDR ADOCK 05000219 P
I.
TECHNICAL SPECIFICATION CHANGE REQUEST (TSCR) NUMBER 226 GPU Nuclear requests that the following replacement pages be inserted into the existing Technical Specifications:
Replace existing pages 1.0-8,3.3-3 through 3.3-8a,3.10-2,3.10-3,3.10-4 and 3.10-5 with the attached replacement pages 1.0-8 and 3.3-3 through 3.3-8a, 3.10-2,3.10-3,3.10-4 and 3.10-5.
II.
REASON FOR' CHANGE Section 3.3.F.2 of the Oyster Creek Technical Specifications permits power operation with four of the five recirculation loops operable, provided certain conditions are met.
If only three loops are operable, however, the TS require plant shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. However, analysis indicates that the plant may be safely operated at 90%
power with three operable recirculation loops. The proposed change permits continued plant operation with a maximum of two inoperable recirculation loops, provided certain conditions are met.
Under the current specification, if one loop is inoperable and routine maintenance or other work is required on a second loop, plant shutdown would be required. Such an occurrence would challenge the operators and unnecessarily cycle the plant.
Approval of the change, however, would provide Cyster Creek with operational j
flexibility consistent with previous NRC Safety Ev.duation Reports (SER). It would also enhance Oyster Creek's availability to and support of the regional power grid.
Two definitions are added to Section 1 of the Technical Specifications to specify the difference between an idle recirculation loop and an isolated recirculation loop.
These definitions have been incorporated into the' specification to provide an explicit description of acceptable valve configurations. In addition, several paragraphs have been added to the Bases of Section 3.3 and one paragraph in the Bases of Section 3.10 has been modified. In each case the Bases section has been segmented from the Specification, which affects the pagination of the Bases.
.III.
SAFETY EVALUATION JUSTIFYING CHANGE When operating with two inoperable recirculation loops the proposed section 3.3.F.2.b requires that the reactor core thermal power not exceed 90% of rated power.
This is a physical limitation of the plant conditions since maximum power is approximately 90% of rated at the maximum recirculation flow with only three recirculation pumps operating. The 90% of rated power value was used as the maximum power level for a three-loop LOCA analysis. As required by Appendix K, a 102% of the maximum power for three-loop operation, or 92% of rated full power
i operation, was used in the analysis. As such, the 90% of rated power becomes a limiting condition for three-loop operation. The results of this analysis conform to all the requirements of 10 CFR 50.46 and Appendix K. The analysis demonstrates that three-loop operation does not require a MAPLHGR multiplier when the both inoperable loops are idle.
The MAPLHGR multiplier specified in the proposed section 3.3.F.2.a is 98% of limits when operating with one isolated recirculation loop. The MAPLHGR multiplier requirement is a result of a reduction in coolant inventory due to loop isolation that may lead to earlier core uncovery during a LOCA. Since the proposed change will allow only one isolated loop, the four-loop MAPLHGR multiplier is applicable to three-loop operation.
With fewer operating loops, each functioning loop will be carrying a higher.
percentage of the initial core recirculation flow. If a break in one loop occurs, then a faster core flow coastdown will result, which could yield an earlier boiling transition time. For limiting large breaks this has no impact on the results because no coastdown credit was taken in the analysis. For the smaller breaks (in which there is large margin to 10 CFR 46 limits), the impact is not significant.
Recirculation pump trip transients have been analyzed for single and multiple pump trips. While the transient in general is very mild, the case of simultaneous trip of all five pumps is considered to be the limiting event among all possible recirculation pump trip events. For three loop operation, given the requirement that power level be maintained at or below 90% of rated, the transient resulting from the loss of all three pumps would be bounded by the five pump trip event.
.Thr'ee loop operation will result in a reduced flow (less than rated) power operation.
An evaluation of the results of an Oyster Creek Extended Load Line Limit Analysis (ELLLA) justifies operation in an extended region on the power / flow map, including reduced flow operation. The ELLLA analysis supports operation below 100% power and up to the rod block line on the power / flow map. All normal three-loop operation will occur within this region.
If the requested changes are approved, the Core Operating Limits Report (COLR) will be revised to include a statement about MAPLHGR multipliers. A change to the Bases of Specification 3.10 is being made since MAPLHGR limits with less than five operable recirculation loops has been incorporated into the Specification.
IV.
NO SIGNIFICANT HAZARDS DETERMINATION GPU Nuclear has determined that his TSCR poses no significant hazard as defined by 10 CFR 50.92.
n 1.
The proposed change, which permits three loop operation with a maximum of two idle or one idle and one fully isolated loop, will provide adequate safety margins during transient and accident conditions. As a result, the proposed change will not increase the probability of occurrence of an accident previously evaluated in the SAR since the accident occurrence is not dependent on the number of operating recirculation loops.
2.
The proposed change permits three loop operation with a maximum of two idle or one idle and one fully isolated loop. The change will not create a possibility for an accident or transient of a different type than any previously identified in the SAR since no changes are being made to the plant.
- 3. -
The proposed change will not decrease the margin of safety as' defined in the basis of any Technical Specification. All relevant transient and accident scenarios have been analyzed for the conditions of three loop operation and have demonstrated adequate margin to safety f
limits.
I V.
IMPLEMENTATION 3
GPU Nuclear requests that this amendment be effective thirty days after issuance.
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