ML14183A219
| ML14183A219 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 04/29/1992 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML14183A218 | List: |
| References | |
| NUDOCS 9205040277 | |
| Download: ML14183A219 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 140 TO FACILITY OPERATING LICENSE NO. DPR-23 CAROLINA POWER & LIGHT COMPANY H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 DOCKET NO. 50-261
1.0 INTRODUCTION
By letter dated October 31, 1991, the Carolina Power & Light Company (licensee) submitted a request for changes to the H. B. Robinson Steam Electric Plant, Unit No. 2 (HBR2), Technical Specifications (TS).
The proposed change is a reduction in the current TS requirement for shutdown margin (SDM), during the refueling mode, from 10 to 6 percent delta k/k. The current TS requirement for the minimum boron concentration in the water of the primary and connected systems during refueling would remain unchanged at 1950 ppm boron.
- 2.
EVALUATION The HBR2 has two TS requirements relating to reactivity limitations during refueling operations. These are TS 3.8.1.f (refueling) which requires 1950 ppm boron in the water during refueling and TSs 3.6.1.b (Containment Integrity) and 3.10.8.3 (required SDMs) which currently require the refueling SDM to be at least 10% delta k/k. For past operating cycles, the two specifications have been compatible with 1950 ppm boron providing more than 10% delta k/k. However, increase in cycle length and fuel enrichment have resulted in HBR2 not being able to achieve 10% delta k/k SDM with 1950 ppm during the next cycle.
Of the various possible solutions to this problem, e.g., higher refueling water storage tank boron concentration, more burnable poison, limiting cycle length, or a change to the SDM requirement, CP&L has proposed to adopt an SDM change as being the most straightforward and causing the least change to core design, other systems or operations. While some of the older Westinghouse reactors have had a 10 percent SDM, most of them, the current Westinghouse Standard Technical Specifications (STS), and the proposed new STS have a 5 percent SDM requirement. Thus, the proposed 6 percent SDM for HBR2 would remain conservative compared to currently acceptable requirements.
9205040277 920429 PDR ADOCK 05000261, P__
-2 The 6% delta k/k SDM and the retention of the 1950 ppm boron requirement (in TS 3.8.1.f) have been determined to be sufficient (1) to assure subcriticality with all control rods withdrawn (they are normally fully inserted for refueling operations with at most one rod at a time withdrawn), (2) to provide sufficient shutdown to meet the requirements of the boron dilution during shutdown operations event analysis (time available for operator action is 41 minutes compared to a required 30) and (3) to cover any reactivity uncertainty during fuel movement in the fuel shuffle procedures. The subcritical reactor status with all rods withdrawn with 1950 ppm boron will remain in the basis for TS 3.8, with a note added to indicate its connection to post-LOCA boron requirements.
The necessary requirements for shutdown reactivity status are retained by this change in SDM. Among the various solutions, this change provides the least disruption to operations of the reactor. The required SDM remains conservative relative to that required for other similar reactors. Therefore, we conclude that the proposed change is acceptable.
3.0
SUMMARY
We have reviewed the reports submitted by CP&L for HBR2 proposing TS changes relating to the change of the refueling mode SDM from 10 to 6 percent delta k/k. Based on this review, we have concluded that appropriate documentation was submitted and the proposed TS changes satisfy staff positions and requirements in these areas. Operation in the mode proposed for HBR2 is acceptable.
4.0 STATE CONSULTATION
In accordance with the Commission's regulations, the State of South Carolina official was notified of the proposed issuance of the amendment. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The 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. The NRC 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 offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no
-3 public comment on such finding (56 FR 66917).
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.
6.0 CONCLUSION
The Commission 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 the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: H. Richings Date: April 29, 1992
AMENDMENT NO. 140 TO FACILITY OPERATING LICENSE NO. DPR ROBINSON, UNIT NO. 2 Docket File NRC PDR Local PDR PDII-1 Reading S. Varga (14E4)
E. Adensam P. Anderson R. Lo OGC D. Hagan (MNBB 3302)
G. Hill (4) (P1-37)
Wanda Jones (P-130A)
C. Grimes (11E22)
H. Richings R. Jones ACRS (10)
OPA OC/LFMB L. Reyes, RII cc:
Robinson Service List