ML20206N628

Safety Evaluation Supporting Amends 145 & 137 to Licenses NPF-10 & NPF-15,respectively

ML20206N628
Person / Time
Site:	San Onofre
Issue date:	12/16/1998
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20206N619	List: ML20206N614 ML20206N628
References
NUDOCS 9812210115
Download: ML20206N628 (2)

Text

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r NUCLEAR REGULATO"Y COMMISSION WASHINGTON r.G. 20006 0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.145 TO FACILITY OPERATING LICENSE NO. NPF-10 AND AMENDMENT NO.137 TO FACILITY OPERATING LICENSE NO. NPF-15 SOUTHERN CALIFORNIA EDISON COMPANY SAN DIEGO GAS AND ELECTRIC COMPANY THE CITY OF RIVERSIDE. CALIFORNIA THE CITY OF ANAHEIM. CALIFORNIA SAN ONOFRE NUCLEAR CENERATING STATION. UNITS 2 AND 3 DOCKET NOS. 50-361 AND 50-362

1.0 INTRODUCTION

By application dated May 7,1998, Southern Califomia Edison Company, et al. (SCE or the licensee) requested changes to the Technical Specifications (Appendix A to Facility Operating License Nos. NPF-10 and NPF-15) for San Onofre Nuclear Generating Station, Unit Nos. 2 and

3. The proposed changes would revise the reference for obtaining the thyroid dose conversion factors used in the definition of Dose Equivalent lodine 131 (I-131)in Technical Specification (TS) Section 1.1, " Definitions" for each plant. Specifically, the reference to " Table E-7 of

~

Regulatory Guide 1.109, Rev.1, NRC 1977" is replaced with a reference to the Intemational Commission on Radiological Protection Publication 30 (ICRP-30), Supplement to Part 1, Pages 192 212, Tables titled, " Committed Dose Equivalent in Target Organs or Tissues per Intake of Unit Activity."

Radioactive releases from a nuclear power plant must be evaluated in terms of a calculated dose (radiation exposure) to the thyroid gland of a member of the public. A dose conversion factor (DCF) is needed to convert the amount of I-131,1-132,1-133,1-134, and 1-135 that might be released at a plant to the amount of intemally deposited radioacitivity in an organ. The TSs define DOSE EQUIVALENT l-131 as that concentration of I-131 in microcuries/ gram that alone would produce the same thyroid dose as the quantity of iodine isotopes that would be present in a release at the plant.

2.0 EVALUATION The current TS enables the licensee to determine the potential health effects of a release of radioactivity on the public in terms of its effect on the thyroid of an equivalent amount of I-131 based on a DCF described in Revision 1 of RG 1.109," Calculation of Annual Doses to Man 9812210115 981216 PDR ADOCK 05000361 PDR P

• l from Routine Releases of Reactor Effluents for the Purpose of Evaluating Compliance with 10 CFR Part 50, Appendix 1," published in 1977. The NRC staff in NUREG 1432," Standard Technical Specifications, Combustion Engineering Plants," Rev. O, published in 1992 specified RG 1.109 as one of two sources for DCF that could be used at Combustion Engineering plants.

Using the DCFs, the licensee is able to ensure that levels of activity in the reactor coolant system and the secondary coolant system are both within limits to ensure that thyroid doses to individuals within the exclusion area boundary, low population zone, and control room during a design basis accident would be within the dose limits per 10 CFR Part 100, Section 11 and 10 CFR Part 50, Appendix A, General Design Criterion 19.

The NRC in Rev.1 of NUREG-1432, issued in April 1995 ;isted three sources for DCFs that are used widely in the industry: TID-14844, Revision 1 of RG 1.109, and the Intemational Commission on Radiological Protection Publication 30 (ICRP-30) (1980). This last reference is the most current listing of DCFs and it reflects improvements in obtaining data on decay schemes and half-lives, and more physical data for lodine and dose to the thyroid. Further, the licensee noted in its May 7,1998, submittal that using the DCFs provides a more realistic estimation of thyroid doses and also results in a reduction in the calculated thyroid dose consequences of design basis accidents for the plants by almost 30 percent.

Based on the above information and the fact that the NRC has already approved the use of the DCFs included in ICRP-30 as reflected in NUREG 1432, Rev.1, the staff finds that this proposed change to the TS for the plants to be acceptable.

3.0 STATE CONSULTATION

In accordance with the Commission's regulations, the California State official was notified of the proposed issuance of the amendments. The State official had no comments.

4.0 ENVIRONMENTAL CONSIDERATION

These amendments relate to changes in recordkeeping, reporting, or administrative procedures or requirements. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(10). Pursuant to 10 CFR 51.22(b) no environmental impset statement or environmental arsessment need be prepared in connection with the issuance of the amendments.

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 oper2 tion in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the commen defense and security or to the health and safety of the public.

Principal Contributor: Chet Poslusny, PDIV-2/NRR Date: December 16, 1998 l