ML20205P295
| ML20205P295 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 03/27/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20205P258 | List: |
| References | |
| NUDOCS 8704030230 | |
| Download: ML20205P295 (3) | |
Text
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NUCLEAR REGULATORY COMMISSION 5
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT N0. 141 T_0 FACILITY OPERATING LICENSE N0. DPR-49 IOWA ELECTRIC LIGHT AND POWER COMPANY CENTRAL IOWA POWER COOPERATIVE CORN BELT POWER COOPERATIVE DUANE ARNOLD ENERGY CENTER DOCKET NO. 50-331
1.0 INTRODUCTION
By letter dated August 29, 1986, Iowa Electric Light and Power Company (IELP/ licensee) proposed to change the Technical Specifications (TS) for the Duane Arnold Energy Center (DAEC). The changes to TS 3.3.C.1/.?/.3 and TS 4.3.C are concerned with control rod scram testing. Revisions were also proposed for the Bases 3.3 and 4.3.
The rapid insertion of control rods during a scram is required to bring the reactor subcritical at a rate fast enough to prevent fuel damage.
After initial fuel loading and subsequent refuelings, all control rods are required to be scram tested within the constraint of the TS.
The existing scram insertion times of TS 3.3.C.1/.2/.3 are based on the time required to insert control rod (s) from a fully withdrawn position to a percentage of the fully inserted distance. Percent inserted, however, is not directly measurable at DAEC while even rod positions For measurement purposes, the percent inserted was given a are.
conservative correspondence to the closest even numbered rod position.
For example, to represent 5% insertion, rod position 44, corresponding to 8.33% inserted was chosen to represent 5% inserted rather than rod position 46, which corresponds to 4.17% inserted.
During the beginning of cycle scram time tests for Cycle 8, the licensee could not meet the scram time for 5% insertion usNg rod position 44. Therefore, the licensee proposed to change the rod scram time basis from a percentage insertion bases tc a rod position basis.
This would allow a more accurate determination of rod scram times based on directly obtainable plant data.
8704030230 870327 PDR ADOCK 05000331 P
. 2.0 EVALUATION Average scram insertion time Rod position is linearly related to percentage inserted. The staff compared the proposed average scram insertion time versus rod position (percentage inserted) with the existing TS. We find the proposed average scram insertion time acceptable since there is no significant change to the previously accepted scram rate.
Maximum Scram Insertion Time The existing TS relates to a maximum scram insertion time for 90%
insertion. The proposed TS relates to a rod position (04) which corresponds to about 91.6% insertion for the same maximum scram insertion time. We find this acceptable since this scram rate will be higher than that required for the 90% insertion and thus will not adversely affect previously accepted safety analyses.
3.0 TECHNICAL SPECIFICATION CHANGES i
The licensee has proposed the following TS changes:
a)
TS Sections 3.C.1/.2/.3 The column "% Inserted from Fully Withdrawn" has been deleted.
Revised rod scram insertion times for new-rod positions have been included.
Rod position "04" has replaced "90% insertion."
b)
TS Section 4.3.C.1 The surveillance requirement has been changed to clarify rod scram time testing based on rod position rather than percent insertion.
The licensee also proposed editorial changes for TS Section 3.C.1/.3 and 4.3.C.1 and Bases 3.3 and 4.3.
We find the proposed TS changes acceptable since they will result in administrative changes which will allow more accurate monitoring of scram insertion rates based on directly obtainable plant data.
Previous safety analyses will not be adversely affected.
We find the proposed Bases acceptable since the changes are editorial.
4.0 ENVIRONMENTAL CONSIDERATION
S This 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 and changes to the surveillance requirements. The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the typed, of any effluents that may be released offsite, and that there is not significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards i
consideration and there has been no public comment on such finding.
Accordingly, the amendment meets 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 amendment.
5.0 CONCLUSION
We have 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, and (2) such activities will be conducted in compliance with the Commission's regulations, and 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:
D. Katze Dated:
March 27, 1987 i
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