ML17139C700
| ML17139C700 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 11/14/1984 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17139C699 | List: |
| References | |
| NUDOCS 8411260110 | |
| Download: ML17139C700 (4) | |
Text
1 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION AMENDMENT N0.26 TO NPF-14 SUSQUEHANNA STEAM ELECTRIC STATION UNIT 1 DOCKET NO. 50-387 Introduction The 'licensee in letters dated April 10, 1984 and May 18,
- 1984, proposed changes to the Technical Specifications of the operating license for Susquehanna Steam Electric Station, Unit 1 which are as follows:
a)
Raise the allowable water temperature in the spray pond from 81'F or less during normal operations to a temperature of 88'F or less during normal operations.
b)
Revise Technical Specifications as related to Special Reporting requirements discussed in NRC Generic Letter 83-43 dated December 19, 1983 and in response to changes in 10 CFR 50.72 and 10 CFR 50.73.
Evaluation a)
Ultimate Heat Sink S ra Pond)
.In Section 2.4.4 of the Susquehanna SER Supplement No. 6, the staff concluded that the Susquehanna Ultimate Heat Sink (Spray Pond) complied with Regulatory Guide 1.27 and met the requirements of GDC-44.
This conclusion was subject to a technical specification that requires that the water temperature in the spray pond be 81'F or less during normal plant operation.
The basis for the 81'limit was that the licensee's conservative analysis had shown that by having the initial pond temperature at 81'r less, the maximum pond temperature during a
design basis accident would be below the design level of 95'F.
Although the licensee proposed the 81'emperature limit, they recognized at. the time that solar heating during the hot summer months might result in pond temperatures higher than 81'F.
Thus the licensee continued their investigation in an effort to find a means by which the temperature limit of 81'ould be increased.
The licensee has now completed a new analysis of the thermal performance of the spray pond. This new analysis shows that the spray pond can provide sufficient cooling for a design basis accident (LOCA in one unit and a safe shutdown of the other) if the pond operating temperature is limited to 88'F.
On the basis of this analysis the licensee requested that the Technical Specification limit of 81'F be increased to 88'F.
This new analysis differs from the original analysis in that the effects of wind have now been taken into consideration.
Originally wind effects 841i260110 841114 PDR ADOCK 05000387 P
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-2" were ignored.
Since winds increase the efficiency of the heat transfer
- process, ignoring the wind's contribution to heat transfer in the original analysis was a conservative assumption.
The licensee also used meteorological data from the airport near Scranton in the new analysis, instead of the Harrisburg airport data used in the original analysis.
the licensee believes that the Scranton data is more representative of the site than the Harrisburg data because the Scranton airport is only 27 miles from the site while the Harrisburg airport is 70 miles away and separated by a mountain range.
The staff agrees that the Scranton airport is a more appropriate source of meteorological data.
Another change from the original analysis involves solar effects on the cooling pond.
This change results in a higher solar heat load contri-bution to the spray pond than the original analysis.
A fourth difference between the original and the new analysis is the decay heat data.
The staff reviewed the new decay heat data submitted by the licensee and found them acceptable with one small modification.
Because the new heat loads did not take into account the addition of a fifth diesel generator at the plant, the heat load data points were increased to account for the possibility of the fifth diesel being on line with three of the existing four diesels.
The final change in the licensee's new analysis involves a revision in the emergency service water (ESW) flow rate.
The revision reflects the results of a two unit flow balance test preformed in December 1983.
Using conservative methods described in NUREG-0733, the staff independently analyzed the thermal performance wf the spray pond.
In its analysis the staff also used the long term,
{ 1949-1982) weather record for the airport near Scranton to determine the periods of most adverse meteorology with respect to spray pond cooling performance and water loss.
It was then conservatively assumed that the peak ambient spray pond temperature would occur at the same time as the peak temperature due to plant heat rejection and a computer simulation was made to determine the combined peak spray pond temperature.
Since the meteorology record used was for the Scranton airport and not for the site, the staff compared the long term airport data with the limited onsite data to determine if there were any significant discrep-ancies between the two sets.
This comparison showed that there are some biases in the two data sets.
The average bias for the onsite data indicated that the spray pond temperature should be slightly higher than predicted from the Scranton airport data.
Thus the staff increased the peak spray pond temperature to account for this bias.
Based on its analysis, the staff concludes that if a design basis accident were to occur when the average temperature in the spray pond was at 88'F, the pond has sufficient cooling capacity to provide plant cooling water at a design temperature of 95'F.
On this basis, the staff finds increasing the spray operating temperature in Technical Specification from 81'F to 88'F acceptable.
b)
S ecial Re ortin Requirements Effective January 1,
1984, the requirements contained in Section 50.72 and Section 50.73 to 10 CFR Part 50 replaced all existing requirements for licensees to report "Reportable Occurrences" as defined in individual plant Technical Specifications.
These changes were discussed in Generic Letter 83-43 dated December 19, 1983.
In response to changes in 10 CFR 50.72 and 10 CFR 50. 73, the licensee in a letter dated Nay 18,
- 1984, proposed Technical Specification changes to be consistent,,with the HRC rule changes.
The staff has reviewed these changes and found them acceptable because the changes are administrative and clarify the Technical Specifications.
Environmental Consideration A portion of this amendment involves a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The-staff has determined that the amendment in this regard involves no significant increase in the amounts, and no significant change in the types of any effluents that may be released offsite, and that there is no significant increase in individual or commulative occupational radiation exposure.
The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding.
Accordingly, the part of this amendment involving spray pond operability meets the eligibility criteria'for, categorical exclusions set forth in 10 CFR 51.22(c)(9).
The remainder of the amendment involves changes to recordkeeping and reporting requirements and meets the eligibilitycriteria for categorical exclusion set forth in 10 CFR 51.22 (C)( 10).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared, in connection with the issuance of this amendment.
Conclusion l<e have concluded, based on the considerations discussed above,,that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed
- manner, and (2) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment wi 11 not be inimical to the common defense and security or to the health and safety of the public.,
Dated:
NOV 14 1984