ML20100D967
| ML20100D967 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 03/12/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20100D955 | List: |
| References | |
| NUDOCS 8504030202 | |
| Download: ML20100D967 (2) | |
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UNITED STATES t
NUCLEAR REGULATORY COMMISSION h.
g WASHINGTON, D. C. 20555 e
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.113 TO LICENSE NO. 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 The proposed amendment would change the Duane Arnold Energy Center (DAEC)
Technical Specifications to (1) change the additional snubber testing in the event of a snubber failure, from 10% to 5%, (2) delete the requirement to increase the drag force by 50% when the snubbers are functionally tested, (3) delete the snubbers list from the Technical Specifications in accordance with the Nuclear Regulatory Comission guidance of Generic Letter 84-13, and (4) correct some errors.
2.0 Evaluation Iowa Electric Light and Power Company's (the licensee) current Technical Specifications for functional testing of snubbers requires an initial sample size of 10% of the total number of snubbers in the plant. The first change proposed by the licensee is to reduce the required number of additional snubbers to be tested for every failed snubber discovered during the functional testing from 10% to 5% of the total number of snubbers in the plant.
In the absence of a suitable snubber failure data base, we had required that for every failed snubber the licensee test 10% of the snubbers in the category of the failed snubber. Subsequently, the ASME OM-4 group developed a sampling plan which requires that only 50% of the initial sample size (10%) need be tested for each failed snubber. The staff finds the ASME position acceptable. Therefore the licensee proposal to test 5% snubbers for the failed snubbers is acceptable.
The licensee proposed a second change that 50% increase in the drag force when the snubbers are functionally tested be deleted. The licensee states that the test machines used for snubber testing use loads up to 5,000 pounds with a sensitivity of 0.1% or 5 pounds force. The measured drag force of a smaller snubber could be of the order of 5 pounds. A 50%
increase in the drag force may, therefore, not be measurable with any accuracy or reliability. Since the 50% increase in the drag force required for snubber tests was conservatively set, we find that the removal of this requirement will not significantly affect the operability of the snubbers.
We, therefore, find the proposed change to be acceptable.
28' W BEyp P
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The third proposed change is to delete the snubber listing from the Technical Specifications. This proposal is a direct response to NRC Generic letter 84-13, " Technical Specifications for Snubbers" dated May 3, 1984.
In that letter we specified that all snubbers other than speci'ied exceptions are required to be operable but the listing of the snubbers in the Technical Specifications is no longer reouired. The licensee has complied with our Generic Letter 84-13, and we find the proposed change is acceptable.
The fourth proposed change consists of administrative changes consisting of typographical error corrections and deletion of a paragraph referring to a table which was previously deleted. The staff has reviewed the reauested administrative changes and finds them acceptable.
3.0 Environmental Considerations This amendment involves a ihange in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The staf# 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 this amendment involves no significant hazards consideration and there has been no public comment on i
such finding. Accordingly, this 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 this amendment.
4.0 Conclusion We have concluded, based on the considerations discussed above, that (1) there is reasonable assurance that the bealth 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 this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
P. K. Shaw and M. C. Thadani Dated: March 12,1985