ML18016A571
| ML18016A571 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 09/08/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML18016A570 | List: |
| References | |
| NUDOCS 9809140355 | |
| Download: ML18016A571 (6) | |
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UNITED STATES NUCLEAR REGULATORY COIVIMISSION WASHINGTON, D.C. 205ai-0001 Tl N BYT FFC N
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-4 By letter dated October 31, 1996, the Carolina Power and Light Company (CP8L or the licensee) requested changes to the Technical Specifications (TS) requirements for the Harris Nuclear Plant (HNP). Specifically, the licensee requested a change to TS 3/4.7.5, "Ultimate Heat Sink," to reduce the maximum water temperature from 95'F to 94'F, and increase the minimum main reservoir level from 205.7 feet mean sea level to 215 feet mean sea level. The licensee's request was submitted to reflect the results of revised calculations and analyses that had been completed to address Generic Letter (GL) 89-13, "Service Water System Problems Affecting Safety-Related Equipment."
D Section 3.7.5 of the existing HNP TS requires (in part) a minimum main reservoir water level at or above 205.7 feet Mean Sea Level, USGS datum, and a water temperature as measured at the respective intake structure of less than or equal to 95'F.
In addressing GL 89-13, the licensee performed additional calculations and analyses to assure that the heat removal capability of the ultimate heat sink (UHS) was adequate.
A hydraulic model of the emergency service water system (ESWS) was used to correlate service water flow rates through safety-related heat exchangers with reservoir water levels.
CP8 L found that under worst-case accident conditions, a minimum reservoir level of 215 feet was necessary to provide sufficient flow to assure adequate heat removal when the maximum equipment design inlet temperature of 95'F is assumed.
The licensee has established an administrative limitthat requires a minimum main reservoir water level of 215 feet pending NRC review and approval of this TS amendment request.
The licensee also performed an analysis to establish the maximum initial reservoir water temperature.
By using the worst 10-day meteorological conditions (i.e., the 10-day period that results in the peak initial pre-accident reservoir temperature), CP&L calculated a maximum pre-accident reservoir temperature of 94.2'F.
In its submittal, CP8 L stated that a pre-accident reservoir temperature of 94.2'F resulted in a final reservoir temperature (30 days post-Loss of coolant accident [LOCA])of 95.12'F.
The staff noted that the Section 2.4.11 of the Firial Safety Analysis Report (FSAR) states that "a pre-accident reservoir temperature of 94'F would result in a final, 30 day, post-LOCA temperature of 95.12 F." During a conference call, the licensee clarified this discrepancy by stating that the FSAR was correct. Assuming thermal stratification of the UHS, the licensee determined that the maximum resultant temperature would be 94.97'F.
In order to assure that the maximum equipment design inlet temperature of 95'F is 9809i40355 980908 PDR ADQCK 05000400 P
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~ r not exceeded, the licensee has established an administrative limitof 94'F for the maximum reservoir temperature pending NRC review and approval of this TS amendment request.
3.0 WILIIAJ The staffs review criteria for the UHS is discussed in several different sections of NUREG-0800, "Standard Review Plan For The Review of Safety Analysis Reports For Nuclear Power Plants," July 1981, (SRP). The sections that are most applicable to the licensee's request are Section 2.4.11, "Cooling Water Supply," and Section 9.2.5, "Ultimate Heat Sink."
Regulatory Guide 1.27, "Ultimate Heat Sink for Nuclear Power Plants," is also referred to by the SRP and provides additional guidance.
In short, the UHS must be able to dissipate reactor decay heat and heat from safety-related structures, systems and components for at least 30 days following design-basis accidents.
The licensee's TS amendment request to increase the minimum main reservoir level from 205.7 feet mean sea level to 215 feet mean sea level, and reduce the maximum water temperature from 95'F to 94'F, establishes requirements that are more restrictive than those previously approved by the NRC and contained in the current TS for the HNP. The licensee has determined that these changes are necessary in order to.
assure that design-basis heat removal requirements will be satisfied and to assure that equipment temperature limitations willnot be exceeded.
Although the licensee's calculations indicate that the UHS could reach up to 95.12'F (assuming no thermal stratification), which slightly exceeds the maximum design basis inlet water temperature of 95'F for some equipment, several conservatisms associated with this worst-case analysis (as described in the staff's review criteria and discussed above) make it extremely unlikely that the water temperature of the UHS willexceed 95'F.
Given the conservatism in the calculation, the staff concludes that the difference of 0.12'F (between the calculated maximum UHS temperature and the design basis inlet water temperature for some equipment) is insignificant in this application and is considered to be acceptable.
4.0 TAT S
0 In accordance with the Commission's regulations, the State of North Carolina officialwas notified of the proposed issuance of the amendment.
The State official had no comments.
5.0 NV R NMENTAL ONSIDERA IO The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC 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 individual or cumulative occupational radiation exposure.
The Commission has previously issued a proposed finding that the amendment involves no signiTicant hazards consideration, and there has been no public comment on such finding (61 FR 64382). Accordingly, the amendment meets the eligibilitycrite.ia for categorical exclusion set forth in 10 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 the amendment.
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V Based on the information provided by the licensee, the staff finds that the changes are appropriate and necessary to establish requirements that are consistent with the plant design-basis.
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public willnot be endangered by operation in the proposed manner, (2) such activities willbe conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment willnot be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: J.Tatum Date:
September 8, 1998
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