ML20154P327
| ML20154P327 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 05/27/1988 |
| From: | Shelton D TOLEDO EDISON CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| 1-802, NUDOCS 8806030298 | |
| Download: ML20154P327 (3) | |
Text
e TOLEDO EDISON 4 cm e-y,emw Docket No. 50-346 DONAU) CL SHELTON va % -e m,
(419]249 23CU License No. NPF-3 Serial No. 1-802 lby 27, 1988 United States Nuclear Regulatory Commission Document Control Desk Vashington, D. C.
20555 Subj ec t: Response to Inspection Report 88007 Gentlemen:
Toledo Edison has received Inspection Report 88007 (Log No. 1-1788, dated April 27, 1988) and provides the following response.
Violation:
88007-06 Technical Specification 6.8.1.a. requires that written procedures shall be established, implemented and maintained for activities listed in Appendix "A" of Regulatory Guide 1.33, November 1972.
Appendix "A" Section 3.c. of Regulatory Guide 1.33 lists filling and venting the main steam system as an activity.
Contrary to the above on March 11, 1908, the licensee failed to implement Plant Procedure PP 1102.10, Revision 16, dated July 21, 1986, "Plant Shutdown and Cooldown", in that it did not vent the steam generators during fill to prevent pressurization with the main steam isolation valves closed.
Response
Acceptance or Denial of the Alleged Violation Toledo Edison acknowledges the alleged violation, i
Reason for the Violation l
On March 11, 1988 the plant was in cold shutdown (Mode 5) making preparations for an extended refueling outage per Plant Procedure PP 1102.10, "Plant Shutdown and Cooldown." Vhen the Reactor l
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Dockot No. 50-346 License No.'NPF-3 Serial No. 1-802 Page 2 Coolant System temperature is less than 200' F, PP 1102.10 directs the operator to proceed to Steam Generator (SG) vet layup condition per System Procedure SP 1106.08, "Steam Generator Secondary Side Fill, Drain and Layup" to continue plant cooldovn.
SP 1106.08 directs the operator to increase the Steam Generator level to 620 inches using'the Motor Driven Feed Pump to place the SG's in vet layup condition. While filling the SG's per these directions, Steam Generator 2 vas inadvertently pressurized i
to a peak pressure of 954 psia. This unanticipated pressure condition occurred as a result of filling the SG vithout providing 1
an adequate vent path. No significant safety consequences resulted from the noted pressure condition since the SG downcomer temperatures were near 140' F.
The Davis-Besse Technical Specifications require that the temperature of the secondary j
coolant in the SG's be greater than 110' F vhen the secondary side pressure is greater than 237 psig to ensure that pressure induced stresses in the SG's do not exceed the maximum allovable fracture toughness stress limits.
Therefore, the pressurized condition was within the Technical Specifications allovable limits and the design limits of the SG/ secondary system.
As indicated in Violation 88007-06, failure to maintain strict adherence to PP 1102.10, which states, "if MSIV's are closed the SG's must be vented to prevent pressurization during fill", was the major contributing factor to this occurrence. An additional contributing factor was the inadequate interface between the two procedures utilized to perform this evolution. This factor is evidenced by the precautionary note in PP 1102.10 which required the SG's be vented when the HSIV's are closed. The precautionary note was placed after the procedure step that directs the operator to fill the SG in accordance with SP 1106.08.
The combination of these factors and the lack of attention to detail by the participants involved in this evolution resulted in the pressurization of Steam Generator 2.
Corrective Action Taken and Results Achieved All on-shift Operc+1ons Department personnel have been counseled regarding the inadvirtent pressurization incident. The briefings which vere conducted included the cause of the occurrence and the actions which should tave been taken.
System Procedure SP 1106.08 has been changed to clearly require i
that the Atmospheric Vent Valves (AVV) be opened to vent the Steam Generators during fill to vet layup if the HSIV's are closed.
In addition, Plant Procedure PP 1102.10 vill be revised to provide an improved interface with SP 1106.08 to preclude recurrence of this event.
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Dockot Ns. 50-346 License No. NPF-3 Serial No. 1-802 Page 3 Date when Full Compliance vill be Achieved Compliance vill be achieved upon approval of the revision to PP 1102.10 containing the changes noted above.
PP 1102.10 is currently in an inactive status to allow incorporation of changes due to outage modifications. These changes as well as the changes mentioned previously vill be incorporated into the next revision of PP 1102.10. Approval of this procedure revision is expected by August 31, 1988, which is prior to its next required use.
Very truly yours,
[h RVG tit cct DB-1 Resident Inspector A, B. Davis, Regional Administrator A, V. DeAgazio, NRR Project Manager
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