ML20070B506
| ML20070B506 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 01/24/1991 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20070B494 | List: |
| References | |
| NUDOCS 9101310202 | |
| Download: ML20070B506 (2) | |
Text
- - - _ ________
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- k UNITED STATES t
NUCLEAR REGULATORY COMMISSION g
WASHINGTON. D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMEN 0 MENT NO.142 TO FACILITY OPERATING LICENSE NO. OPR-51 ENTERGY OPERATIONS, INC.
ARXANSAS NUCLEAR ONE, UNIT NO. 1 DOCKET NO. 50-313 LNTRODUCTION 3y [[letter::1CAN079003, Application for Amend to License DPR-51,changing Tech Spec 4.7.2, Control Rod Program Verification, by Removing Unnecessary Restriction in Method of Verification of Proper CRD Patching|letter dated July 10, 1990]], Entergy Operations, Inc. (the licensee) requested an amendment to the Technical Specifications (TSs) appended to facility Operating License No. DPR-51 for Arkansas Nuclear One, Unit No.1 ( ANO-1). The proposed amendment would revise Technical Specification 4.7.2 regarding the verification of proper control rod drive patching. The limitation of less than two inches of control rod movement has been revised to ensure sufficient travel is allowed for verification or problem identification.
In addition, the amendment more accurately reflects the conditions under which patch verification is required.
EVALUATION The Control Rod Drive (CRD) System translates the reactor control signal to a linear motion of the control rods. A patch panel is used to assign specific control rod drives to the power supplies. Changes in the power supply connections to the control rods ("repatching") are performed while the reactor is shutdown. Technical Specification 4.7.2 identifies the surveillances required to ensure proper operation and position indication following repatching activities.
Existing Techr.ical Specification 4.7.2 requires verifiution of each control rod "whenever the control rod drive panel is locked..?. The specification limits the allowable rod movement to perform this verification to two inches or less.
The licensee has proposed to revis2 the wording of Technical Specification 4.7.2 to more accurately reflect the conditions under which patch verification is required. This was accomplished by replacing the locking of the patch panel criterion with the actual reconnection of the patch which is performed during plant outages. This change ensures that routine maintenance activities which do not disturb he patch do not initiate an unnecessary patch verification during plant conditions in which it is not practical to perform the verification procedure.
The proposed amendment revises the restriction of two inches or less control rod movement for patch verification to allow sufficient movement for verification or problem identification. This change assures that proper rod 9101310202 910124 PDR ADOCK 05000313 P
c verifications are performed but are not unnecessarily complicated by accuracy limitations and/or inoperable rod position indication reed switches.
The physical distance between reed switches and the associated indication limite-tions could actually preclude satisfying the existing verification requirements if one or more reed switches were found to be inoperable.
The allowance of greater rod movement may also assist in the identification and correction of problems associated with the patching procedure.
Other Technical Specifications such as 1.2 and 3.1.3 which deal with required shutdown margins and minimum conditions for criticality exist to prevent inadvertent criticality.
These Technical Specifications are applicable during the plant conditions in which the patch verification is performed and require adequate shutdown margin (1A$k/k) be maintained.
Therefore, the allowance of greater rod movements during the patch verification procedure does not introduce inadvertent criticality or other safety concerns but does provide beneficial operational flexibility.
Based on its review, the staff agrees with the licensee that the clarification of those conditions requiring patch verification and the removal of the two inch rod movement restriction are appropriate.
Therefore, the staff finds the licensee's proposed TS change to be acceptable.
The staff also notes that the licensee has made minor editorial changes to the Bases, and finds them to be acceptable as well.
ENVIRONMENTAL CONSIDERATION The amendment involves a change in a requirement with respect to the installa-tion or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes in surveillance requirements.
The 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 of fsite, and that there is no significant increase in individual or cumulative occupational radiation exposures.
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.
Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR Section 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.
CONCLUSION The staff 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, 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.
Dated: January 24, 1991 Principal Contributor:
W. Reckley, PDIV-1 I