ML14183A698
| ML14183A698 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 10/17/1995 |
| From: | Mozafari B NRC (Affiliation Not Assigned) |
| To: | Hinnant C CAROLINA POWER & LIGHT CO. |
| References | |
| TAC-M93570, NUDOCS 9510240336 | |
| Download: ML14183A698 (3) | |
Text
October 17, 1995 Mr. C. S. Hinnant, Vice President Carolina Power & Light Company H. B. Robinson Steam Electric Plant, Unit No. 2 3581 West Entrance Road Hartsville, South Carolina 29550
SUBJECT:
CHANGE TO TECHNICAL SPECIFICATION BASIS SECTION 3.10.1.5 REGARDING CONTROL ROD MISALIGNMENT FOR THE H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 (TAC NO. M93570)
Dear Mr. Hinnant:
By letter dated June 22, 1995, Carolina Power & Light Company (CP&L) proposed a change to the H. B. Robinson Steam Electric Plant, Unit No. 2 (HBR),
Technical Specifications (TS) Basis section 3.10.1.5. The Basis change reflects the results of the plant's operating Cycle 17 accident analysis by reducing the analyzed deviation of a single control rod at full power conditions from a complete misalignment of 12 feet to a misalignment of 9 feet above its bank or 12 feet below its bank.
The NRC staff has reviewed the proposed basis change regarding a control rod misalignment at full power and has no objection to your proposed change.
Enclosed is a copy of the revised Basis page.
Sincerely, (Original Signed By)
Brenda Mozafari, Project Manager Project Directorate II-1 Division of Reactor Projects -
I/Il Office of Nuclear Reactor Regulation Docket No. 50-261 Distribution Docket File; DVerrelli, RI
Enclosure:
Basis page 4.4-10 PUBLIC PD2-1 RF cc w/enclosure:
See next page SVarga JZwolinski OGC FILENAME -
H:\\DRPE\\PD2-1\\ROBINSON\\ROB93570.LTR ACRS (4)
OFFICE LA:PDII-PM:A D/P I NAME Dunning on BM afari a he s DATE 10//7/95 10//0/95 10/___5 COPY e /No Yes No Yes N_
OFFICIAL RE ORD COPY 9510240336 951017 PDR ADOCK 05000261 P
0 0
Mr. C. S. Hinnant H. B. Robinson Steam Electric Carolina Power & Light Company Plant, Unit No. 2 cc:
Mr. R. E. Jones Mr. Dayne H. Brown, Director General Counsel - Legal Department Department of Environmental, Carolina Power & Light Company Health and Natural Resources Post Office Box 1551 Division of Radiation Protection Raleigh, North Carolina 27602 Post Office Box 27687 Raleigh, North Carolina 27611-7687 Karen E. Long Assistant Attorney General Mr. Robert P. Gruber State of North Carolina Executive Director Post Office Box 629 Public Staff - NCUC Raleigh, North Carolina 27602 Post Office Box 29520 Raleigh, North Carolina 27626-0520 U.S. Nuclear Regulatory Commission Resident Inspector's Office Mr. Max Batavia, Chief H. B. Robinson Steam Electric Plant South Carolina Department of Health 2112 Old Camden Road Bureau of Radiological Health Hartsville, South Carolina 29550 and Environmental Control 2600 Bull Street Regional Administrator, Region II Columbia, South Carolina 29201 U.S. Nuclear Regulatory Commission 101 Marietta St., N.W., Ste. 2900 Mr. J. Cowan Atlanta, Georgia 30323 Manager Nuclear Services and Environmental Mr. Dale E. Young Support Department Plant General Manager Carolina Power & Light Company Carolina Power & Light Company Post Office Box 1551 - Mail OHS7 H. B. Robinson Steam Electric Plant Raleigh, North Carolina 27602 3581 West Entrance Road Hartsville, South Carolina 29550 Public Service Commission State of South Carolina Post Office Drawer 11649 Columbia, South Carolina 29211 Mr. R. M. Krich Manager -
Regulatory Affairs Carolina Power & Light Company H. B. Robinson Steam Electric Plant, Unit No. 2 3581 West Entrance Road Hartsville, South Carolina 29550
Th$specified control rod insertionW mits meet the design
-basis criteria on (1) potential ejected control rod worth and peaking factor,(4 (2) radial power peaking factors. FAH.
and (3) required margin shutdown.
The various control rod banks (shutdown banks, control banks) are each to be moved as a bank: that is, with all rods in the bank within one step (5/8 inch) of the bank position. Position indication is provided by two methods: a digital count of actuation pulses which shows the demand position of the banks, and a linear position indicator (LVDT) which indicates the actual rod position.(2) At rod positions 2 200 steps, full power reactivity worths of the control rods are sufficiently small such that a 15-inch indicated misalignment from the rod bank has no significant effect on the incore power distribution and is therefore allowable. For rod positions < 200 steps, maintaining indicated rod position within 7.5 inches of the average of the indicated bank position provides an enforceable limit which assures design distribution is not exceeded. In the event that an LVDT is not in service, the effects of a malpositioned control rod are observable on nuclear and process information displayed in the control room and by core-thermocouples and in-core movable detectors. The determination of the hot channel factors will be performed by means of the movable in-core detectors.
The two hours in 3.10.1.5 are acceptable because the misalignment of a single control rod up to 9 feet above its bank or 12 feet below its bank does not result in exceeding core safety limits in steady state operation at rated power and is short with respect to probability of an independent accident. If the condition cannot be readily corrected, the specified reduction in power will ensure that design margins to core limits will be maintained under both steady state and anticipated transient conditions.
3.10-11 AMENDMENT NO. 71 REVISED BY NRC LETTER DATED OCTOBER 17, 1995