ML20059D066
| ML20059D066 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 01/03/1994 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20059D065 | List: |
| References | |
| NUDOCS 9401060392 | |
| Download: ML20059D066 (3) | |
Text
- - -
.i
- %47 '
4 UNITED STATES
[--
p NUCLEAR REGULATORY COMMISSION-
.*e
^
1*
't WASHINGTON, D.C. M0001 -
LM
,-/
na SAFETY EVALUATION BY THE OFFICE'0F NUCL' EAR' REACTOR REGULATION RELATED TO AMENDMENT'N0S. 144 AND 148 TO FACILITY OPERATING LICENSE-N05. DPR-24 AND DPR-27 WISCONSIN ELECTRIC POWER COMPANY POINT BEACH NUCLEAR PLANT. UNIT NOS. 1 AND 2 DOCKET NOS. 50-266 AND 50-301
1.0 INTRODUCTION
By letter-dated November 24, 1992, Wisconsin Electric Power. Company-(Wisconsin Electric or the licensee) requested amendments to the control rod and power
' distribution limits Technical Specifications (TSs) for the Point Beach Nuclear Plant, Units 1 and 2.
The proposed amendments would' revise TS Section 15.3.10.A.5 by removing any reference to the hot shutdown. condition and make the section applicable only during an approach to criticality.
Shutdown requirements will continue to be governed by the existing shutdown requirements specified in Section 15.3.10.A.3.
2.0 BACKGROUND
2.1 Current License Condition The current license condition as stated in the TSs is applicable for both Units 1 and 2 as follows:
(1)
Section 15.3.10. A.5 requires that the critical rod positionL not be lower than the insertion limit for zero power when the reactor is in a hot shutdown condition or during any approach to criticality.
This requirement ensures that there is sufficient shutdown reactivity associated with the rods to place the plant in;its hot shutdown condition following a reactor trip.
2.2 Proposed Changes The proposed revision will remove any reference to the hot shutdown-condition l-and make the section only applicable during an approach to criticality.
(1)
Technical Specification 15.3.10. A.5 is being modified as follows:
"During -any approach to criticality, except for physics tests, the J critical rod position shall not be lower than the.insertien likiit' for zero power.
That is,.if the control rods were withdrawn' in normal sequence with no other reactivity change, the reacts.r would:
t not be critical until the control banks were above-the insertion -
limit."
'9401060392 940103 PDif ADDCK 05000266
- P.
(
w
' i 3.0 EVALUATION The intent of TS 15.3.10. A.5 is to prevent a reactor (at zero power) from going critical with the control rods below the insertion limits.
These insertion limits provide for attaining hot shutdown following a reactor trip, even if the highest worth control rod remains fully withdrawn.
When the reactor is in hot shutdown, several procedural conditions must b et before control banks can be moved to achieve criticality. One of the conditions that must be met is a calculation of the estimated rod position (ERP). This calculation is performed to determine a set of conditions that will achieve a criticality given a set of conditions of a previous criticality.
The ERP calculation is typi ally performed following a planned or an unplanned reactor trip.
In the EF".alculation, it is assumed that the minimum rod position is at least forty ; 1ps above the zero power rod insertion limit.
This condition will ensure that reactor criticality occurs-with the rods above the insertion limits so that sufficient shutdown margin will be present.
Immediately following a trip, the existing power defect may be greater than the difference in rod worth between the 100 percent power rod insertion limit and the 0 percent power rod insertion limit. This would result in the critical rod position being below the zero power rod insertion limit.
The most probable tima that this situation is likely to happen is toward end of life, when it is assumed that the magnitude of the power defect will be at maximum as a result of U-735 depletion.
~
Because this change will only affect Section 15.3.10.A.5, pertaining to the hot shutdown condition while approaching criticality, and because requirements will continue to be governed by the existing shutdown margin requirements specified in Section 15.3.10.A.3, reactor safety and operator actions are not compromised.
Therefore, the staff finds this change acceptable.
4.0
. STATE CONSULTATION In accordance with the Commission's regulations, the Wisconsin State official was notified of the proposed issuance of the amendments. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
These amendments change a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 or change a surveillance requirement. The staff has determined i
that the amendments involve 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 published i
i t t~
Y:
i
-a proposed finding that these amendments involve no significant hazards-consideration and there has been no public comment on such finding
-(58 FR 12270). Accordingly, these amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 551.22(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 these amendments.
6.0 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 i
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 amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
A. Attard Date: January 3,1994
'I i
P i
i i
a T
l
~
_