ML20091R358
| ML20091R358 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 08/23/1995 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20091R347 | List: |
| References | |
| NUDOCS 9509060354 | |
| Download: ML20091R358 (3) | |
Text
.-.
_ pa ucu
/
d UNITED STATES NUCLEAR REGULATORY COMMISSION
\\..* lE E
WASHINGTON, D.C. 200 6 0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.124TO FACILITY OPERATING LICENSE NO. NPF-10 AND AMENDMENT NO.113 TO FACILITY OPERATING LICENSE NO. NPF-15 SOUTHERN CALIFORNIA EDISON COMPANY SAN DIEGO GAS AND ELECTRIC COMPANY THE CITY OF RIVERSIDE. CALIFORNIA' f
THE CITY OF ANAHEIM. CALIFORNIA SAN ON0FRE NUCLEAR GENERATING STATION. UNITS 2 AND 3 DOCKET NOS. 50-361 AND 50-362 a
f
1.0 INTRODUCTION
By letter dated September 16, 1994, Southern California Edison Company, et al.
l-(SCE or the licensee) submitted a request for changes to the Technical-Specifications (TS) for San Onofre Nuclear Generating Station (SONGS), Unit i
Nos. 2 and 3.
The proposed changes would revise the linear heat rate (LHR) limit from 13.9 kw/ft to 13.0 kw/ft in Technical Specification (TS) 3/4.2.1,
" Linear Heat Rate." The Bases of this TS would also'be revised to reflect the new value.
I 2.0 EVALUATION Section 50.46(b)(1) of 10 CFR Part 50 states that the calculated maximum fuel element cladding temperature shall not exceed 2200*F.
The purpose of TS i
3/4.2.1 is to prevent this temperature limit from being exceeded by p1heing a i
limit on the steady state LHR. The current TS value for the LHR limit is 13.9 kw/ft.
The licensee proposes to reduce this limit to 13.0 kw/ft to restore and provide additional analysis margin in the large break loss of coolant accident (LBLOCA). This additional margin is needed to support the use of an optimized fuel is J.ing pattern and anticipated future plant design and operational changes.
By utilizing the optimized fuel loading pattern, a longer fuel cycle length i
.can be achieved due to a reduction in the core neutron leakage. -The improved I
fuel cycle length, however, affects the analysis for the LBLOCA due to more adverse radial power peaking factors at beginning of core life (BOL). The more adverse BOL radial peaking factors result in an increase in the evaluated peak cladding temperature (PCT), which is why the licensee proposes to reduce the LHR limit.
In addition, various parameters in the LBLOCA reanalysis were i
9509060354 950823*
2
- j PDR ADOCK 05000361 j
P-PDR i
b :
i revised to accommodate anticipated changes in plant design and operation.
l Examples of these changes include:
(1) expected increases in steam generator l
tube plugging level and (2) anticipated reductions in reactor vessel inlet temperature.
The reanalysis of the LBLOCA was performed using the Asea Brown Boveri -
l Combustion Engineering 1985 LBLOCA Evaluation Model. This model has been 1
previously approved by the staff and is referenced in Section 15.1.2 of the Safety Evaluation Report for SONGS Units 2 and 3 (NUREG-0712). -
Results of the LBLOCA reanalysis show that all acceptance criteria were met with the LHR limit reduced from the present limit of 13.9 kw/ft to 13.0 kw/ft.
The PCT calculated by the reanalysis was 2160*F, which is within the required limit of 2200*F.
The licensee has determined that the SONGS units can be operated with a lower j
LHR limit of 13.0 kw/ft without affecting unit performance.
Recent investigations performed by the licensee found that the normal maximum LHR value, including all applicable uncertainties, is approximately 12.0 kw/ft.
The difference between the TS LHR limit of 13.0 kw/ft and the normal maximum i
LHR of 12.0 kw/ft is sufficient to ensure that this TS change has minimal operational impact.
j The staff has reviewed the proposed changes to TS and the supporting analysis and concludes that the proposed TS change is acceptable.
f
3.0 STATE CONSULTATION
j In accordance with the Commission's regulations, the California State official was notified of the proposed issuance of the amendment.
The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendments change a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR 1
Part 20 and change surveillance requirements. The NRC staff has determined that the amendments involve 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 i
occupational radiation exposure.
The Commission has previously issued a 1
proposed finding that the amendments involve no significant hazards considers-tion, and there has been no public comment on such finding (59 FR 55892).
Accordingly, the amendments meet 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 amendments.
5.0 CONCLUSION
Tae 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.
Principal Contribetor:
M. Fields Date:
August 23, 1995 I
i 4
1 i
I