ML20205Q815
| ML20205Q815 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 04/16/1999 |
| From: | Alexion T NRC (Affiliation Not Assigned) |
| To: | Cottle W HOUSTON LIGHTING & POWER CO. |
| References | |
| TAC-MA2498, TAC-MA2499, NUDOCS 9904220077 | |
| Download: ML20205Q815 (5) | |
Text
e Mr. William T. Cottle April 16, 1999 President and Chief Executive Officer STP Nuclear Operating Company South Texas Project Electric Generating Station P. O. Box 289 Wadsworth, TX 77483
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION - PROPOSED AMENDMENTS ON OPERATOR ACTION FOR A SMALL-BREAK LOSS-OF-COOLANT ACCIDENT, SOUTH TEXAS PROJECT, UN!TS 1 AND 2 (TAC NOS. MA2498 AND MA2499)
Dear Mr. Cottle:
i The Nuclear Regulatory Commission staff is reviewing STP Nuclear Operating Company's July 28,1998, amendment application associated with the Replacement Steam Generator Project.
4 On the basis of its review, the staff has determined that additional information is needed as discussed in the enclosed request for additional information (RAl). This request was discussed with Mr. Mark VanNoy of your staff on March 30,1999, and a mutually agreeable response of within 45 days from the date of this letter was established. The staff appreciates the efforts expended with respect to this matter.
Sincerely, ORIGINAL SIGNED BY:
Thomas W. Alexion, Project Manager, Section 1 Project Directorate IV & Decommissioning Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-498 and 50-499
Enclosure:
As stated cc w/ encl: See next page DISTRIBUTION:
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April 16, 1999 Mr. William T. Cottle President and Chief Executive Officer STP Nuclear Operating Company South Texas Project Electric Generating Station P. O. Box 289 Wadsworth, TX 77483
SUBJECT:
REQUEST FOR ADDITIONAL INFORMATION - PROPOSED AMENDMENTS ON OPERATOR ACTION FOR A SMALL-BREAK LOSS-OF-COOLANT ACCIDENT, SOUTH TEXAS PROJECT, UNITS 1 AND 2 (TAC NOS. MA2498 AND MA2499)
Dear Mr. Cottle:
The Nuclear Regulatory Commission staff is reviewing STP Nuclear Operating Company's July 28,1998, amendment application associated with the Replacement Steam Generator Project.
On the basis of its review, the staff has determined that additionalinformation is needed as discussed in the enclosed request for additional information (RAI). This request was discussed with Mr. Mark VanNoy of your staff on March 30,1999, e od. mutually agreeable response of within 45 days from the date of this letter was established. F ' staff appreciates the efforts expended with respect to this matter.
Sincerely, m)
.o w Thomas W. Alexion, Project Manager, Section 1 Project Directorate IV & Decommissioning 1
Division of Licensing Project Management Office of Nuclear Reactor Regulation I
Docket Nos. 50-498 and 50-499 j
Enclosure:
As stated cc w/ encl: See next page
Mr. William T. Cottle STP Nuclear Operating Company South Texas, Units 1 & 2 cc:
Mr. Comelius F. O'Keefe Jack R. Newman, Esq.
Senior Resident inspector Morgan, Lewis & Bockius U.S. Nuclear Regulatory Commission 1800 M Street, N.W.
P. O. Box 910 Washington, DC 20036-5869 Bay City, TX 77414 Mr. T. H. Cloninger Vice President A. Ramirez/C. M. Canady Engineering & Technical Services City of Austin.
STP Nuclear Operating Company Electric Utility Department P. O. Box 289 721 Barton Springs Road Wadsworth, TX 77483 Austin,TX 78704 Office of the Govemor Mr. M. T. Hardt ATTN: John Howard, Director Mr. W. C. Gunst Environmental and Natura!
City Public Service Board Resources Policy P. O. Box 1771 P. O. Box 12428 San Antonio,TX 78296 Austin,TX 78711 4
Mr. G. E. Vaughn/C. A. Johnson Jon C. Wood 3
Central Power and Light Company Matthews & Branscomb
)
P. O. Box 289 One Alamo Center Mail Code: N5012 106 S. St. Mary's Street, Suite 700 Wadsworth,TX 74483 San Antonio, TX 78205-3692 INPO Arthur C. Tate, Director Records Center Division of Compliance & Inspection 700 Galleria Parkway Bureau of Radiation Control Atlanta, GA 30339-3064 Tex'.s Department of Health 1100 West 49th Street Regicnal Administrator, Region IV Austin, TX 78756 U.S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 400 Jim Calloway Arlington,TX 76011 Public Utility Commission of Texas Electric Industry Analysis D. G. Tees /R. L Balcom P. O. Box 13326 Houston Lighting & Power Co.
Austin, TX 78711-3326 P. O. Box 1700 Houston,TX 77251 Judge, Matagorda County Matagorda County Courthouse 1700 Seventh Street Bay City, TX 77414
1 Reauest for Additionalinformation Operator Action for a Small Break Loss-of-Coolant Accident South Texas Proiect. Units 1 and 2 The staff has determined that STP Nuclear Operating Company (the licensee) has addressed the nine criteria contained in NRC Information Notice (IN) 97-78, " Crediting of Operator Actions in Placs of Automatic Actions and Modifications of Operator Actions, including Response Times." However, the following additional information is needed on IN 97-78 Items (1), (4), (8),
and (9) i (1) the specific operator actions required---Attachment 3 of the July 28,1998, submittal Identifies that the operator action being credited in the small-break loss-of-coolant accident (SBLOCA) reanalysis and proposed license amendment is, "to lower the SG
[ steam generator) PORV [ power-operated relief valve) setpoints within 45 minutes after accident initiation."
The staff needs further description of how the operator lowers the SG PORV setpoints (i.e., what are the actual procedural steps followed and manual actions taken by the operator to lower SG PORV setpoints). A copy is requested of the applicable current procedure (s) and proposed revision (s). A description of the displays and controls required by the operator to perform the required action is also requested.
(4) the procedural guidance for required actions---Attachment 3 of the July 28,1998, submittal identifies that the " operator s etion to lower the safety-grade SG PORV setpoints will be added to the STP Errergency Operating Procedures [EOPs]."
See response to item (1) for additional information required by the staff.
(8) the ability to recover from credible errors in performance of manual actions, and the expected time required to make such a recovery---Attachment 3 of the July 28, 1998, submittal identifies that "[o)perators at STP are highly trained and proficient in their duties.... Recent simulator exercises have demonstrated the ability of the STP operators to complete the required operator actions as written in the EOPs and to diagnose system responses." The licensee continues by stating that "[t]he proposed operator action is iequired to be completed at or prior to 45 minutes after the accident.
Consequently, STPNOC believes that sufficient time is available for operators to complete the required actions,...."
The staff needs a description of the simulator exercises that address attributes such as the number of crews used; the composition of the crews (normal crew size versus minimal; lice nsed operators versus simulator instructors); " naive" crews (i.e., unaware of the scenario / specific operator action to reduce the setpoints) or crews knowledgeable in advance of the scenario / operator action to be performed; and the success / failure rate of the crews exercised.
ENCLOSURE l
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2 The licensee should also describe what credible operator error (s) can occur, their consequences, and the actions that would be necessary to successfully recover from-the error (s). The staff needs to evaluate the licensee's analysis of the effect on plant performance and safety of the operator failing to perform the required action correctly (i.e., acts of omission).
(9) consideration of the risk significance of the proposed operator actions-of the licensee's submittal identifies that STPNOC has submitted a Level 2 Probabilistic Risk Assessment (PRA) and an Individual Plant Examination (IPE) in a letter dated August 28,1992. The licensee stated that the PRA "models the operator action to depressurize the RCS [ reactor coolant system] for a small break LOCA, including depressurizing the secondary side using the SG PORVs if the steam dumps are not available.... The frequency of failure is based on sequence specific operator interviews and is 4.4x10~8 on demand. Since the operator action is currently modeled, the risk to core damage is unchanged."
The staff needs further information that describes the modeling of operator actions; specifically, is the model that was used in the 1992 examination still app!icable (i.e.,
does it exist now?)? Is the operator action required in the licensee's amendment request modeled in the 1992 PRA or IPE7 Does the PRA model both operator success and failure in the performance of the required action and, what are the results from modeling the, success and failure of the operator action?
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