ML20207G559
| ML20207G559 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 06/09/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20207G554 | List: |
| References | |
| NUDOCS 9906110208 | |
| Download: ML20207G559 (3) | |
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NUCLEAR REGULATORY COMMISSION
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WASWINGTON, D.C. 20066-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 216 TO FACILITY OPERATING LICENSE DPR-57 AND AMENDMENT NO.157 TO FACILITY OPERATING LICENSE NPF-5 SOUTHERN NUCLEAR OPERATING COMPANY. INC.. ET AL.
EDWIN 1. HATCH NUCLEAR PLANT. UNITS 1 AND 2 DOCKET NOS. 50-321 AND 50-366
1.0 INTRODUCTION
By letter dated January 21,1999, which superseded a letter dated July 22,1998, Southern Nuclear Operating Company, Inc. (SNC/ licensee), proposed license amendments to change the Technical Specifications (TS) for the Edwin 1. Hatch Nuclear Plant, Units 1 and 2. The proposed changes would increase the Allowable Values for the high radiation trip for the reactor building and the refueling floor ventilation exhaust monitors to s 80 mR/hr for both monitors.
The current setpoint for the reactor building ventilation exhaust monitor is s 20 mR/hr and the current setpoint for the refueling floor ventilation exhaust monitor is s 60 mR/hr.
2.0 BACKGROUND
- The function of the reactor building and the refueling floor ventilation exhaust radiation monitors, in combination with other accident mitigation systems, is to limit fission product release during a postulated design basis accident. The monitors automatically initiate closure of the appropriate secondary containment isolation valves and start the standby gas treatment
- system. Therefore, the Allowable Values for the trip set points are chosen to insure radioactive
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releases do not exceed offsite dose limits.
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3.0 EVALUATION in the supporting documentation for the Technical Specifications amendment request, the licensee calculated the radiation field (mR/hr) that would exist at each of the ventilation monitors following a fuel handling accident and the corresponding monitors' response to that field..Using the most conservative radiation monitor response, the license determined that an analytical limit of 340 mR/hr would limit releases such~that the resulting offsite doses were well within Title 10 of the Code of Federal Reaulations (10 CFR) Section 100.11 acceptance criteria.
The licensee concludes that the proposed Allowable Value of s80 mR/hr is well below the analyticallimit.
The staff reviewed the licensee's conclusion and performed an independent calculation to verify the acceptability of the licensee's conclusion..The staff determined that changing the alarm set point to s80 mR/hr would not have an adverse impact on the Design Basis Fuel Handling i
Accident. The staff preformed an independent calculation of the fuel handling accident using
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c the assumptions of Regulatory Guide 1.25," Assumptions Used For Evaluation of the Potential Radiological Consequences of a Fuel Handling Accident in the Fuel Handling and Storage Facility for Boiling and Pressurized Water Reactors".
The staff's calculations confirmed that the thyroid doses at the Exclusion Area Boundary (EAB) and Low Population Zone (LPZ) from the fuel handiing accident in the auxiliary building meet
- the acceptance criteria.' The paramotors which the staff uti!! zed in its assessment are presented in Table 1. For the fuel handling accident in the auxiliary building, the staff calculated a dose of 0.017 rem thyroid at the EAB and at the LPZ. The acceptance criteria at the EAB and LPZ for this accident are contained in Standard Review Plan Section 15.7.4 of NUREG-0800 (75 rem thyroid dose; 25 percent of 10 CFR Part 100 guideline of 300 rem). The staff agrees with the licensee's conclusion that the proposed change will not affect any.of the assumptions used to analyze the fuel handling accident. Therefore, the proposed change is acceptable.
Table 1 ASSUMPTION USED FOR CALCULATING RADIOLOGICAL CONSEQUENCES Parameters Quantity Power Level (Mwt) 2763
{
Number of Fuel Rods Damaged 125 i
TotalNumberof FuelRods 34720
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Shutdown Time, Hours 24 1
' Power Peaking Factor 1.5 Filter Efficiencies (%)
elemental 95 organic 95 Recentor Point Variables
' Atmosphere Relative Concentration, X/O (sec/m')'
Exclusion Area Boundary 0-2 hours (1250m) 1.7E-6 Low Population Zone, duration (1250m).
1.7E-6 Note: Dose conversion factor from ICRP-30 were utilized for all calculations.
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F 3-TABLE 2 RADIOLOGICAL CONSEQUENCES PROJECTED BY STAFF. REM Thyroid dose Acceptance Criteria Exclusion Area Boundary,0-2 hours 0.017 75 Low Population Zor.e, duration 0.017 75
4.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Georgia State official was notified of the proposed issuance of the amendments. The State official had no comments.
5.0. ENVIRONMENTAL CONSIDERATION The amendments change a requirement with respect to the installation or use of facility components 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 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 9reviously issued a proposed finding that the amendments involve no significant hazaids consideration, and there has been no public comment on such finding (64 FR 24200). 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.
6.0 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 amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: R. Tadesse Date:
June 9,1999
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