ML20055G556

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Safety Evaluation Supporting Amend 129 to License DPR-61
ML20055G556
Person / Time
Site: Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date: 07/19/1990
From:
Office of Nuclear Reactor Regulation
To:
Shared Package
ML20055G554 List:
References
NUDOCS 9007230309
Download: ML20055G556 (3)


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u SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.129 TO FACILITY OPERATING LICENSE NO. OPR-61 CONNECTICUT YANKEE ATOMIC POWER COMPANY HADDAM NECK PLANT DOCKET NO. 50-213 INTRODUCTION Pursuant to 10 CFR 50.90, Connecticut Yankee Atomic Power Company (CYAPCO) has proposed to amend the Operating License No. DPR-61 for the Haddam Neck Plant.

By letter dated May 9, 1990, CYAPCO proposed to amend Technical Specification (TS) Section 5.3, " Fuel Assemblies" to allow the use of Type 304 steinless steel filler rods in place of the fuel rods. The TS request stated that if more than 30 rods in the core or 10 rods in any assembly be replaced the utility would submit a special report to the NRC within 30 days after cycle startup. By letter dated June 8, 1990, CYAPCO amended theic sodest tc, propose operation with two Type 304 stainless steel filler rods in the core for Cycles 16 and 17 only.

In addition, CYAPC0 has requested to correct TS Table 3.3-la, " Reactor Trip System Instrumentation Response Time."

DISCUSSION As result of.the debris induced fuel rod damage during Cycie 15, CYAPC0 reconstituted 92 fuel assemblies. During the fuel reconstitution effort two failed fuel rods were replaced with solid Type 304 stainless steel " filler rods." The current Haddam Neck TS does not address the option of using stainless steel filler rods in place of fuel rods. The proposed change would allow the use of two stainless steel filler rods for Cycles 16 and 17.

The Technical Report Supporting Cycle Operations (TRSCO) has been revised to reflect the impact on the revised Cycle 16 reload design due to fuel reconstitution including the two stainless steel filler rods and removal of the thermal shield, in addition TS Table 3.3-la has been revised to reflect a typographical error in which the less than or equal sign was left out for the Power Range Nuclear Flux Response Time Trip.

EVALUATION Stainless Steel Filler Rods In our safety evaluation dated April 26, 1990, the staff agreed that values of cycle-specific parameter limits that are established using an NRC-approved methodology can be removed from the TSs, as cycle-specific reload analyses I

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using NRC epproved methodology is administrative in nature and there is no impact on plant safety. The insertion of stainless steel filler rods is permissible but requires justification by cycle-specific reload analyses. The L

TRSCO for Cycle 16 submitted by letter dated July 28, 1989 was revised to 4

reflect the following:

s 1.

new core loading pattern and fuel inventory; 2.

analyses performed accounting for the two solid steel " filler rods" and donor fuel rods present in the core; 3.

some accident analyses were reevaluated to assess the impact of revised reload physics parameters, thermal shield removal and an 1

increase in the steam generator tube plugging limit to 600 tubes per I

steam generator; and 4.

some of the core operating limits were changed, such as moderator temperature coefficient, axial offset, and linear heat generation rate.

The impact of the above changes on plant safety have been evaluated in the TRSCO for Cycle 16 and it has been c'etermined that the changes do not impact plant operation of the performance of any safety system.

Based on the above the staff concludes that the plant cu be operated safely, because the plant operation continues to be limited in accordance with the values of cycle-specific parameter limits that are established using an NRC-approved methodology which the staff judges to be valid for this particular core with two solid stainless steel filler rods.

In addition, the use of the two stainless steel filler rods in Cycle 17 will be reanalyzed in the TRSCO for Cycle 17.

The TRSCO is required by the TS to establish cycle / reload parameter limi'.s using NRC approved codes, that maintain the limits of the safety analy.iis.

Based on the Cycle 16 TRSCO analysis, we would expect that the effects of the stainless steel filler rods will not impact plant operation or the perform e ce of any safety system during Cycle 17. Therefore, the staff concludes that the proposed TS change is acceptable.

TS Table 3.3-la TS Table 3.3-la, " Reactor System Instrumentation Response Time" was changed to correct a typographical error.

For the first parameter in the table, the less than or equal sign was left out. The staff agrees that this is a typographical error and the change is purely administrative.

The change is consistent with the purpose of the table to provide minimum reactor trip instrumentation response times and the remaining parameters in the table. Therefore, the staff concludes that the proposed TS is acceptable.

3 ENVIRONMENTAL CONSIDERATION Pursuant to 10 CFR 51.21, 51.32, and 51.35, an environmental assessment and finding of no significant impact have been prepared and published in the Federal Register on July 18, 1990 (55 FR 29283). Accordingly, based upon the environmental assessment we have determined that the issuance of the amendment will not have a significant effect on the quality of the human environment.

CONCLUSION Wehaveconcluded,basedontheconsiderationsdiscussedabove,that(1)there is reasonable assurance that the health ano s?'ety of the public will not be endangered by operation in the proposed manner;a regu(2) such activities will and be conducted in ;ompliance with the Commission lations, 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 publia.

Dated: July 19, 1990 Principal Contributor:

A. Wang l

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