ML20248A829
| ML20248A829 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 05/27/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20248A817 | List: |
| References | |
| NUDOCS 9806010052 | |
| Download: ML20248A829 (2) | |
Text
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UNITED STATES p
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NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. Samaa met I
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1 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION I
RELATED TO AMENDMENT NO.160 TO FACILITY OPERATING LICENSE NO. NPF-49 NORTHEAST NUCLEAR ENERGY COMPANY. ET AL.
MILLSTONE NUCI FAR POWER STATION. UNIT NO. 3 l
DOCKET NO. 50-423
1.0 INTRODUCTION
By letter dated April 7,1998, the Northeast Nuclear Ene;gy Company, et al. (the licensee),
submitted a request for changes to the Millstone Nuclear Power Station, Unit No. 3 Technical Specifications (TS). The requested changes would replace the pressurizer maximum water inventory requirement with a pressurizer maximum indicated level requirement. The proposed amendment would also make editorial changes and modify the associated Bases section.
2.0 EVALUATION TS 3.4.3 specifies the maximum pressurizer water level to preserve the necessary steam space for pressure control during steady state plant operation and to minimize the consequences of potential overpressure and pressurizer overfill transients. Specifically, TS 3.4.3, in part, requires a pressurizer water volume of less than or equal to 92 percent (1656 cubic feet) and is applicable to Modes 1,2, and 3. However, the accident analyses in Chapter 15 of the Final
' Safety Analysis Report (FSAR) assume that the pressurizer level is being maintained at the
-l programmed level, which is a curve that varies linearly from 28 percent for hot zero power to l
61.5 percent for full power operations at Millstone Unit 3. Therefore, TS 3.4.3, as currently written is not consistent with the safety analyses assumptions documented in Chapter 15 of the j
FSAR. In its April 7,1998, letter, the licensee proposed changes to TS 3.4.3 to resolve this inconsistency. The second part of TS 3.4.3 discusses requirements for the pressurizer heaters and is not changed in the proposed amendment request.
In the April 7,1998, letter, the licensee proposed to expand the current TS 3.4.3 into two separate TS (TS 3.4.3.1 and TS 3.4.3.2). TS 3.4.3.1 will be applicable to Modes 1 and 2.
TS Figure 3.4-5 provides the curves of programmed pressurizer level and the operational limits (programmed level +/- 6 percent) for power operation. Limiting Condition for Operation (LCO) 3.4.3.1 requires that the pressurizer water level be maintained at a programmed level
+/-6 percent of full scale. This proposed TS will bound the assumed initial conditions for those transients where pressurizer overfill is a concern (e.g., loss of feedwater, feedwater line break,
'9906010052 980527 PDR ADOCK 05000423 P
. and inadvertent actuation of safety injection system at power). The +/- 6 percent of full scale acceptance criterion in the TS covers the instrumentation uncertainties.
I Proposed TS 3.4.3.2 will be applicable to Mode 3. LCO 3.4.3.2 will require that the pressurizer be operable with a water level less than or equal to 89 percent of full scale. This requirement provides indication that a steam bubble in the pressurizer exists and it also perserves the necessary steam space for pressure control in Mode 3. There is no significant concern regarding the initial pressurizer level in Mode 3 with respect to the safety analyses.
The staff has reviewed the licensee's request and finds that proposed TS 3.4.3.1 and TS 3.4.3.2 are conservative and consistent with the safety analyses documented in Chapter 15 '
of the Millstone Unit 3 FSAR. Therefore, the staff has concluded the changes are acceptable.
The staff has also reviewed the editorial changes and finds them acceptable.
3.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Connecticut State official was notified of the proposed issuance of the amendment. The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
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 and changes surveillance requirements. 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 significant hazards consideration, and there has been no public comment on such finding (63 FR 20219 dated April 23,1998). Accordingly, the amendment meets the eligibility criteria 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.
5.0 CONCLUSION
The Commission has 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, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
l PrincipalContributor: C.Y. Liang Date:
May 27, 1998