ML20210K415
| ML20210K415 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood  |
| Issue date: | 08/13/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20210K408 | List: |
| References | |
| NUDOCS 9708190250 | |
| Download: ML20210K415 (3) | |
Text
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UNITED STATES g
j NUCLEAR REGULATORY COMMISSION p
2 WASHINGTON. D C. 20665-0001 1
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l SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATLQH RELATED TO AMENDMENT NO. 92 TO FACILITY OPERATING LICENSE NO. NPF-37, AMENDMENT NO. 92 TO FACILITY OPERATING LICENSE NO. NPF-66, AMENDMENT NO. 85 TO FACILITY OPERATING LICENSE NO. NPF-72, AND AMENDMENT NO. 85 TO FACILITY OPERATING LICENSE NO. NPF-77 COMMONWEALTH EDISON COMPANY BYRON STATION. UNIT NOS. 1 AND 2RAIDWOOD STATION. UNIT NOS.1 AND 2 DOCKET NOS. STN 50-454. STN 50-455. STN 50-456 AND STN 50-457
1.0 INTRODUCTION
By letter dated June 9,1997, Commonwealth Edison Company (Comed, the licensee) proposed to change the realistic dose values for the process gas system rupture in Section 15.0 of the Byron /Braidwood (B/B) Updated Final Safety Analysis Report (UFSAR). During preparation of a UFSAR change package, Comed discovered that the Final Safety Analysis Report (FSAR) had not been updated to correct an error from the previous revision of the dose calculation. Since the correct dose value is greater than that previously reported, Comed determined that the consequences of the accident had increased, and an unreviewed safety question resulted. In accordance with the provisions in 10 CFR 50.59(c), Comed submitted the change for staff review and approval pursuant to the provisions of 10 CFR 50.90. The doses reported in UFSAR Section 15.0 for the process gas system rupture (Table 15.0-11 for Byron, and Table 15.0-12 fcr Braidwood) are determined based on the limiting event for that system, a waste gas storage tank rupture, which is described in UFSAR Section 15.7.1.3. Two sets of doses are reported: realistic doses and conservative doses. Regulatory Guide (RG) 1.70, " Standard Format and Content of Safety Analysis Reports for Nuclear Power Plants," states. realistic dose evaluations are not required, but may be included in the UFSAR to illustrate the degree of conservatism in the design calculations (e.g., the conservative doses for B/B). The proposed changes are to the realistic doses. The conservative doses are not affected. For Byron, the realistic dose at the exclusion area boundary (EAB) is increased from 6.52E-03 rem to 6.53E-03 rem, and the dose at the low population zone (LPZ) is increased from 1.50E-04 rem to 1.51E-04 rem. For Braidwood, the dose at the EAB is increased from 7.llE-03 rem to 7.14E-03 rem,and the dose at the LPZ is increased from 6.62E-04 rem to 6.63E-04 rem. 9708190250 970813 PDR ADOCK 05000454 P PDR g 7 Q $ / O M c)
\\ ~ These realistic doses from the postulated accident are acceptably small fractions (i.e., less than 10 percent) of the 25 rem whole body does limit required by 10 CFR 100.11. They are also less than the dose criteria of 0.5 rem at the EAB, as established in Standard Review Plan (SRP) Section 11.3, Branch Technical Position (BTP) ETSB 11-5, " Postulated Radioactive Releases Due to a Waste Gas System Leak or Failure" (NUREG-0800). 2.0 EVALUATION In -Section 11.3 of NUREG-0876, " Safety Evaluation Report Related to the Operation of Byron Station, Units 1 and 2," and NUREG-1002, " Safety Evaluation l Report Related to the Operation of Braidwood Station, Units 1 and 2," the l staff reported on its evaluation of the licensee's gaseous waste management system. The staff reviewed the system with respect to the acceptance criteria of SRP Section 11.3, " Gaseous Waste Management Systems," and concluded that the system is acceptable based on its conformance of the design, design l criteria, and design bases to the applicable regulations and RG. The licensee's proposed changes in the calculated realistic dose for a process gas-system rupture do not invalidate the staff's previous conclusions. Technical Specification (TS) 3.11.2.6 restricts the quantity of radioactivity contained in each gas storage tank. As stated in the TS bases, this restriction provides assurance that, in the event of an uncontrolled release of a tank's contents, the resulting maximum (e.g., conservative) whole body dose to an individual at the EAB will not exceed 0.5 rem, the criteria stated in BTP ETSB 11-5. This restriction is not affected by the proposed changes. Accordingly, the staff finds the following proposed changes to the realistic doses to be acceptable, as they are small fractions of the 10 CFR Part 100 dose criteria. (1) For Byron, the dose at the EAB is increased to 6.53E-03 rem; the dose at the LPZ is increased to 1.51E-04 rem. (2) For Braidwood, the dose at the EAB is in:reased to 7.14E-03 rem; the dose at the LPZ is increased to 6.63E-04 rem.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Illinois State official was notified of the proposed issuance of the amendments. 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 Part 20. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types,
y l l. 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 amendments-involve no significant hazards consideration, and there has been no public comment on such finding (62 FR 37079). Accordingly, the amendments-meet the eligibility criteria for categorical exclusion set forth in 10 CFR l 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 l-of the amendments. l 5.0 CONCLUSI0f( The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the l -- 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 amendments will not be inimical to the common defense and security or to the health and safety of the public. The staff, therefore,-concludes that the changes, as stated in this Safety Evaluation, are acceptable and hereby authorizes incorporation of said changes into the UFSAR for Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2. Principal Contributor: S. N. Bailey Date: August 13, 1997 l i .}}