ML20214C139
| ML20214C139 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 11/11/1986 |
| From: | Keiser H PENNSYLVANIA POWER & LIGHT CO. |
| To: | Kister H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| NUDOCS 8611200700 | |
| Download: ML20214C139 (3) | |
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PP&L Pennsylvania Power & Light Company Two North Ninth Street
- Allentown, PA 18101
- 215 / 770-5151 Harold W. Keiser Vice President-Nuclear Operations 215/770-7502 NOV 111986 Mr. Harry B. Kister Chief Project Branch No. 1 Division of Reactor Projects U.S. Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406 SUSQUEHANNA STEAM ELECTRIC STATION NRC INSPECTION REPORT 50-388/86-14 PLA-2752 FILE R41-IC,R41-2 Docket No. 50-387
Dear Mr. Kister:
This letter provides PP&L's response to your letter of October 10, 1986 which forwarded NRC Region I Inspection Report 50-388/86-14 with Appendix A, Notice of Violation.
Your Notice advised that PP&L was to submit a written reply within thirty (30) days of the date of the letter. We trust that the Commission will find the attached response acceptable.
Very truly yours, H. W. Keiser Vice President-Nuclear Operations Attachment cc:
Mr. L. R. Plisco - NRC Senior Resident Inspector Mr. M. C. Thadani - NRC (NRR Project Manager) 8611200700 861111 PDR ADOCK 05000387 G
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RESPONSE TO NOTICE OF VIOLATION VIOLATION (388/86-14-01)
On July 16, 1986 at 4:25 p.m., the 'C' Traversing Incore Probe (TIP) drive control unit on control room panel 2C607 was deenergized due to a burned out computer logic card. During a reactor shutdown on the following day, July 17 at 7:18 p.m., reactor vessel level reached the low level isolation setpoint of 13 inches (Level 3), but the 'C' TIP did not withdraw from the indexer and the j
ball valve did not isolate as designed. Licensee investigation identified that deenergizing the TIP drive control unit (DCU) drawer made the containment isolation function of the TIP inoperable, since the probe was inserted into containment and could not be withdrawn. During the shutdown the other 4 TIP machines functioned properly and isolated.
Upon identification that the TIP did not isolate, the appropriate Limiting Condition for Operation (LCO) was entered. At 8:53 p.m. on July 17, the 'C' TIP was reenergized with a replacement logic card and the TIP withdrew from the indexer and the isolation valve closed.
When the TIP failed to isolate on July 17, a Significant Operating Occurrence Report (S00R 2-86-103) was initiated by the licensee to describe the event and resolve the associated issues. During the S00R review process, the event was determined to be reportable per 10 CFR 50.73(a)(2)(1)(b) in that the unit
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operated in a condition prohibited by Technical Specifications.
On July 16, when the
'C' TIP was deenergized, LCO 3.6.3 for Primary Containment Isolation Valves should have been entered, since the TIP could not be withdrawn automatically on an isolation signal. Technical Specification LCO 3.6.3 states that with one or more of the primary containment isolation valves inoperable, maintain at least one isolation valve operable in each affected penetration that is open and within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> restore the inoperable valve to operable status or isolate the penetration.
If this action cannot be completed, the unit is to be placed in hot shutdown within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and cold shutdown within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
Since the operators did not recognize that deenergizing the TIP drawer defeated the containment isolation function, the appropriate LCO was not entered and the action statement was not performed.
Since the TIP shear valves (explosive valves) were still operable, the first portion of the action statement was satisfied, however the penetration was not isolated nor was the inoperative valve restored to operable status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
In addition, the unit should have been in hot shutdown by 8:25 a.m. on July 17, but it was not shutdown until 7:18 p.m. on July 17 due to high RCS leakage (See Detail 2.3).
The failure to meet the action statement of LC0 3.6.3 is a violation of Technical Specifications.
RESPONSE
- 1) The reason for violation:
Normal plant direction from Health Physics is to allow the TIP probes to i
remain in the indexers inside of containment for a period of three hours after use to allow radiation levels to decrease to reasonably allowable levels. Under normal conditions the isolation function is operable in this configuration. On July 16, 1986 with the "C" TIP probe at the indexer, a burned out logic card created some smoke in the Control Room
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T and led personnel to de-energize the control power. This disabled the containment isolation function by preventing the retraction of the probe and the closing of the ball isolation valve. At this time Operations personnel failed to recognize that entry into LCO 3.6.3 was appropriate.
- 2) Corrective steps which have been taken and the results achieved:
a)
Operating Procedures OP-178-001 and OP-278-001, "TIP Drive System" have been changed to add precautions concerning power being removed or lost, b)
Caution labelo have Neen placed on the Unit 1 and Unit 2 TIP control panels stating " LOSS OF PWR/DEENERGIZING TIP DRIVE DISABLES BALL VLV ISO CAPABILITY ISOLATE OR COMPLY WITH T.S. 3.6.3" c)
Reactor Engineering Procedures which specifically direct TIP operation have been changed to reference a controlling procedure, RE-0TP-011.
This procedure now includes a form to be completed by Operations whenever the TIP's have been returned to their shield positions.
- 3) Corrective steps which will be taken to avoid further violation:
An evaluation will be performed by Health Physics on the continued need for storing the TIP probe at the indexer following use.
This evaluation will be completed by January 15, 1987.
- 4) The date when full compliance will be achieved:
PP&L was in full compliance on July 17, 1986 when the unit was placed in Hot Shutdown at 1918 hours0.0222 days <br />0.533 hours <br />0.00317 weeks <br />7.29799e-4 months <br />. The TIP drive was restored at 2053 hours0.0238 days <br />0.57 hours <br />0.00339 weeks <br />7.811665e-4 months <br /> the
.r' same day.
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