ML20056E537
| ML20056E537 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 08/10/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20056E535 | List: |
| References | |
| NUDOCS 9308240225 | |
| Download: ML20056E537 (3) | |
Text
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.154 TO FACILITY OPERATING LICENSE NO. DPR-40 OMAHA PUBLIC POWER DISTRICT FORT CALHOUN STATION. UNIT N0. 1 DOCKET NO. 50-285
1.0 INTRODUCTION
By letter dated October 9,1992, Omaha Public Power District (OPPD) submitted a request for changes to the Fort Calhoun Station (FCS), Unit No.1 Technical Specifications (TS). The requested changes would revise TS 3.2 (Table 3-5),
" Equipment and Sampling Tests." The proposed revision to TS 3.2 (Table 3-5) reflects the changes made to Section 14.18 of the FCS Updated Safety Analysis Report (USAR), " Fuel Handling Accident (FHA) Analysis." A revised USAR Section 14.18 was submitted by 0 PPD in a letter dated July 9, 1991, and was accepted by the NRC in a letter dated August 14, 1991. The revised FHA analysis did not credit removal of any radioiodine through operation of the spent fuel pool charcoal filter (VA-66). The current TS require a charcoal filter volumetric flow rate of between 9,000 and 12,000 cubic feet per minute (cfm). The proposed amendment would modify the required volumetric rate to between 4,500 and 12,000 cfm. The original design basis for VA-66 indicated that the unit was designed for a rated air flow of 12,000 cfm per manufacturer's drawings. The minimum flow rate was set to be consistent with operating modes of the fans. The change proposed for TS 3.2 (Table 3-5) is based upon recent test data.
This Safety Evaluation addresses the proposed change to the charcoal filter i
volumetric flow rate submitted in a letter dated October 9,1992. The other I
changes proposed by the licensee's October 9, 1992, application are being handled separately.
2.0 EVALUATION To support its proposed change to TS 3.2 (Table 3-5), OPPD conducted a series of tracer gas tests to establish operational configurations. The purpose of the testing was to demonstrate that General Design Criterion (GDC) 19 requirements could be met with the proposed changes to the operation of VA-66 and that VA-66 would mitigate the consequences of a FHA. The tracer gas tests proved that gaseous releases were controlled in accordance with GDC-19. The original design flow rates (9,000-12,000 cfm) were based upon cperating two intake and three exhaust fans. During the tracer gas tests, operation of two intake and three exhaust fans was found to cause flow instability In the l
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- exhaust plenum. The most effective flow through VA-66 was obtained with a system operation of one intake and two exhaust fans, which corresponds to operation within the range of 4,500-12,000 cfm. As a result, the system will operate with a configuration of one intake and two exhaust fans. This optional flow rate range is substantially below the lower limit of the values given in TS 3.2 Table 3-5.
This difference in flow rate is not safety-significant since the revised USAR Section 14.18 analysis does not credit VA-66 for mitigating radiological consequences of the FHA, even though actual tests have demonstrated the effectiveness of VA-66 in reducing radiation doses. As a result of tracer gas testing, it has been concluded that approximately 40% of the radioiodines can be removed by VA-66 at optimal flow rates between 4,000-5,000 cfm. However, since the VA-66 charcoal filter is capable of passing flow rates up to 12,000 cfm, the licensee chose to maintain an upper limit of 12,000 cfm.
t There is also an agreement between OPPD and the NRC that OPPD will commit to keep the section on VA-66 in the TS and to maintain VA-66 operable without including it in the design-basis analysis.
Another proposed change to the TS concerns the column titled "FSAR Section Reference" in Table 3-5 of TS 3.2.
"FSAR" is being changed to "USAR," which is the current nomenclature.
Item 10b.2 in Table 3-5 is also being revised to correct a typographical 3
j error.
Thephrase"5toIpm/m inlet elemental concentration" is being corrected to "5 to 10 mg/m inlet elemental concentration," consistent with Amendment No. 52.
This typographical error was inadvertently incorporated into Table 3-5 in Amendment No.128.
Based on its review, the staff concludes that the proposed changes to TS 3.2 (Table 3-5) are acceptable.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Nebraska 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. 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 (57 FR 55584). Accordingly, the amendment
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l meets 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 i
environmental assessment need be prepared in connection with the issuance of l
the amendment.
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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.
Principal Contributor: Narvaez L. Stinson Date: August 10, 1993 l
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