ML17139C692
| ML17139C692 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 11/14/1984 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML17139C691 | List: |
| References | |
| NUDOCS 8411210331 | |
| Download: ML17139C692 (6) | |
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UNITED STATES NUCLEAR R'EGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION AMENDMENT NO.
3 TO NPF-22 SUSQUEHANNA STEAtI ELECTRIC STATION UNIT 2 DOCKET NO. 50-388 Introduction The licensee in a letter dated April 10, 1984, proposed a change to the Technical Specifications of the operating license for Susquehanna Steam Electric Station, Unit 2 ghich would raise the allowable water temperature in th~ spray pond from 81 F or less during normal operations to a temperature of 88 F or less during normal operations.
Evaluation 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 sp~ay pond be 81 F or less during normal plant operation.
The basis for the 81 limit was the licensee's conserva)ive analysis had shown that by having the initial pond temperature at 81 or less, the maximum pond tempara-ture during a design basis accident would be below the design level of 95 F.
Although the licensee proposed the 81 temperature limit, they recognized at the time that solar heating during the hot summer months might result in a pond temperatures higher than 81 F.
Thus the licensee continued their inves)igation in an effort to find a means by which the temperature limit of 81 could be increased.
The licensee 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 thjs analysis the licen~ee 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 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
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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 meterological data.
Another change from the original analysis involves solar effects on the cooling pond.
This change results in a higher solar heat load contribution to the spray pond than in the original analysis.
A fourth difference between the original and the new analysis is heat data.
The staff reviewed the new decay heat data submitted licensee and found them acceptable with one small modification.
, new heat loads did not take into account the addition of a fifth generator at the plant, the heat load data points were increased for the possibility of the fifth diesel being on line with three existing four diesels.
the decay by the Because the diesel to account of the The final change in the licensee's new analysis involves a revision in the emergency service water (ESW) flow rate.
This revision reflects the results of a two unit flow balance test performed in December 1983.
Using conservative methods described in NUREG-0733, the staff independently analyzed the thermal performance of 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 discrepancies between to two sites.
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 accifent were to occur when the average temperature in the spray pond was at 88 F, the pond has sufficient ~ooling capacity to provide plant cooling water at a
design temperature of 95 F.
On this basis, the staff finds increasing the spray pond operating temperature in Technical Specification 4.7. 1.3 from 81 F
to 88 F acceptable.
Environmental Consideration r
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 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 indivi-dual or cumulative occupationa'l radiation exposure.
The Commission has previously issued a proposed finding that this amendment involves no signifi-cant hazards consideration and there has been no public comment on such finding.
Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in CFR 51.22(c)(9).
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 We 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 activi-ties will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Oated:
NOV 1 4 1S84
Issuance of Amendment No.
to Facilit 0 eratin Licence No NPF-22 Sus ue anna team ectric tat>on, nest DISTRIBUTION ooct F~ie ~
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WMiller, LFMB NGrace EJordan LHarman DBrinkman, SSPB TBarnhart{4)
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