ML20072L673
| ML20072L673 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 08/26/1994 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20072L670 | List: |
| References | |
| NUDOCS 9409010057 | |
| Download: ML20072L673 (3) | |
Text
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NUCLEAR REGULATORY COMMISSION 2
WASHINGTON, D.C. 20565 0001
,o SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT N05.151 AND 155 TO FACILITY OPERATING LICENSE NOS. 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 October 6, 1992, the Wisconsin Electric Power Company, the licensee, proposed administrative modifications to the Point Beach Nuclear Plant, Units 1 and 2 Technical Specifications (TSs) by changing all references of rod position to units of steps rather than inches.
In addition, the proposed TS revision will revise the hsis for Section 15.3.10, " Control Rod and Power Distribution Limits," to clarify the definition of " fully withdrawn" as it concerns Rod Cluster Control Assemblies. Table 15.3.5-5, Section 15.3.10, the basis for Section 15.3.~40, and Figure 15.3.10-1 will also be revised to support these changes.
2.0 fyALUATION 2.1 TS 15.3.10. " Control Rod and Power Distribution Limits" The proposed amendments change all references of rod position in this section from units of inches to units of steps.
The units of steps are preferable because it corresponds with the control room indications used by the operators.
The direct correlation is one step is equal to 5/8 inch of rod motion.
Since there is a direct relationship between steps and inches, this revision is simply a change in format only. Therefore, the staff finds the change acceptable.
2.2 Table 15.3.5-5. " Instrument Operatino Conditions for Indications" The proposed amendments change the reference of rod position in the table's No. 6 " Control Rod Misalignment as Monitored by On-line Computer" from units of inches to units of steps. As stated above, the change in the units is a purely format change only. Therefore, the staff finds the change acceptable.
2.3 Basis for TS 15.3.10. " Insertion Limits and Shutdown Marain" The proposed change to the basis adds a paragraph clarifying the definition of
" fully withdrawn." The new paragraph reads:
9409010057 940026 PDR ADOCK 05000266 P
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"During power operation, the shutdown banks are fully withdrawn.
Fully withdrawn is defined as a bank demand position equal to or greater than 225 steps.
Evaluation has shown that positioning control rods at 225 steps, or greater, has a negligible effect on core power distributions and peaking factors.
Due to the low reactivity worth in this region of the core and the fact that, at 225 steps, control rods are only inserted one step into the active fuel region of the core, positioning rods at this position or higher has minimal effect.
This position is varied, based on a predetermined schedule, in order to minimize wear of the guide cards in the guide tubes of the RCCAs."
The definition of " fully withdrawn' was addressed in Amendments 88 and 93 to Facility Operating Licenses DPR-24 and DPR-27, respectively. Amendments 88 and 93 revised TS 15.3.10 to include footnote (1) which states " fully withdrawn is defined as a bank demand position equal to or greater than 225 steps.
This definition is applicable to shutdown and control banks." At 225 steps withdrawn, the rod control cluster assemblies (RCCAs) move only 0.3 inches into the active fuel.
Because of the low rod worth in the top region of the core, the resultant power distribution perturbations are calculated to be less than 1%, and can be accommodated with available margin.
Similarly, I
the effect on shutdown margin is minimal (0.02% @ (reactivity)) and can be accommodated by available excess shutdown margin (>0.75% 4).
The impact on other key safety parameters was found to be negligible.
Based on the above discussion, the staff finds the change acceptable.
2.4 Fiaure 15.3.10-1. " Control Bank Insertion Limits. Point Beach.
Units 1 and 2" and TS 15.3.10 A.2 The proposed amendments would change the control bank position in Figure 1
15.3.10-1 from percent withdrawn to steps withdrawn. A correlation of 228 steps equals 100% withdrawn will be utilized. When converting percent withdrawn to steps, all fractional values will be rounded up, in the conservative direction, to the next whole step value.
This change is a format change only, therefore, the staff finds the change acceptable.
The proposed amendments add a footnote to TS 15.3.10.A.2 to again state the definition of " fully withdrawn." TS 15.3.10.A.2 reads:
"When the reactor is critical, the control banks shall be inserted no further than the limits shown by the lines on Figure 15.3.10-1."
As previously justified, the definition of
" fully withdrawn" applies to both shutdown and control rods, therefore the footnote is needed.
To further clarify the requirements, a note is being added to Figure 15.3.10-1 that reads "The ' fully withdrawn' parking position range can be used without violating this Figure." The changes are for clarification and are consistent with the previous amendments and with the Basis of TS 15.3.10.
Based on the above discussion, the staff finds the change acceptable.
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3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Wisconsin State official was notified of the proposed issuance of the amendment. The State official had no comments.
4.0 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.
The staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluent 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 these amendments involve no significant hazards consideration and there has been no public comment on such finding (58 FR 16234). The amendments also change a reporting or recordkeeping requirement. Accordingly, these amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9) and (c)(10).
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.
5.0 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 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 these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
G. Dentel J. King Date: August 26, 1994
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