ML20214H140
| ML20214H140 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 05/13/1987 |
| From: | Gucwa L GEORGIA POWER CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| SL-2495, NUDOCS 8705270288 | |
| Download: ML20214H140 (6) | |
Text
Georgia Fbwer Company -
- 333 Piedmont Avenue Att;nta, Georgia 30308 tiephone 404 526-6526 Mailing Address:
Fbst office Box 4545 Atlanta, Georgia 30302 Georgia Power L T. Gucwe Ine southern erectrc systern Manager Nuclear Safety and Licensing SL-2495 1361C X7GJ17-H120 May 13, 1987 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Hashington, D. C.
20555 PLANT HATCH - UNITS 1, 2
-NRC DOCKETS 50-321, 50-366 OPERATING LICENSES DPR-57, NPF INSPECTION REPORT NOS. 50-321/86-43 AND 50-366/86-43 j
Gentlemen:
In response to your letter of April 8,1987, and in accordance with the provisions of 10 CFR Section 2.201, we have enclosed our response to the Notice of Violation associated with the Inspection Report identified above. The Notice of Violation refers to the inoperability of one train of the standby gas treatment system.
If you should have any questions in this regard, please contact us at any time.
Sincerely,
- M L. T. Gucwa MJB/lc
Enclosures:
1.
NRC Notice of Violation 86-43-01 2.
GPC Response to Notice of Violation 86-43-01 c:
(see next page) t 8705270288 870513
/
i PDR ADOCK 05000321 l
G PDR
LGeorgia Powerb U. = S. Nuclear Regulatory Commission May 13,' 1987 Page Two c: Georgia Power Company Mr. t. P. O'Reilly Mr. J. T. Beckham, Jr.
GO-NORMS U.S. Nuclear Regulatory Commission, Region II Dr. J. N. Grace, Regional Administrator Mr. P.~ Holmes-Ray, Senior Resident Inspector - Hatch 1361C
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Georgia Pbwern ENCLOSURE 1
~ NOTICE OF VIOLATION 86-43-01 PLANT HATCH - UNITS 1, 2
- NRC DOCKETS 50-321, 50-366 OPERATING LICENSES DPR-57, NPF-5 INSPECTION REPORT NOS. 50-321/86-43 AND 50-366/86-43 VIOLATION 50-321/86-43-01 and 50-366/87-43-01
" Unit,1 Technical Specifications 3.7.B.1.a~ requires a minimum of three (two in Unit' I and one in Unit 2) of the four independent standby gas treatment system trains to be operable at all times when Unit 1 secondary containment integrity is required.
With one of the Unit 1. standby gas treatment systems inoperable, Unit 1 reactor operation and fuel handling is permitted for seven days provided - that all -active components in the remaining operable standby gas: treatment systems in each unit.be demonstrated to be operable within four hours and daily thereafter..
Further, if the inoperable Unit l' standby gas treatment system is not made fully operable within the seven-day period, the Unit 1 reactor shall be shutdown and placed in the. cold shutdown condition _ within the next 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> and Unit 1 fuel handling operations shall be terminated within four hours.
Unit 2-Technical Specifications 3.6.6.1 requires two' Unit 1 and two Unit 2 independent standby gas treatment subsystems be operable in Conditions 1,
2,- and-3.
With one subsystem inoperable, the inoperable subsystem must be restored to the operable status within seven' days or Unit 2_must be in a least 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 in 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 />.
Contrary to the above, from November 25,_1985 to March 11, 1986 during various times when Unit 1 secondary containment' integrity was required or when Unit 2 was in Condition 1, 2, or 3, the 1 A standby gas treatment subsystem (train) was inoperable for greater than seven days and actions were not taken to: (1) demonstrate all active components in the remaining operable standby gas treatment systems in Units 1 and 2 were operable.
. ithin four hours and daily thereafter, (2) for Unit 1, ' shutdown the w
reactor and be in the cold shutdown condition within the next 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />, (3) terminate Unit 1 fuel handling operations within four hours, or (4) for Unit 2, be 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 in 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 />.
The 1 A train was inoperable because the associated charcoal filter bed had become wet and unable to perform its intended safety function for the removal of methyl iodine.
This is a Severity Level IV violation (Supplement I)."
1361C -
El-1 5/13/87 SL-2495 mm
Georgia Power d ENCLOSURE 2 RESPONSE TO NOTICE OF VIOLATION 86-43-01 PLANT HATCH - UNITS 1, 2 NRC 00CKETS 50-321, 50-366 OPERATING LICENSES OPR-57, NPF-5 INSPECTION REPORT NOS. 50-321/86-43 AND 50-366/86-43 ADMISSION OR DENIAL OF THE VIOLATION:
Georgia Power Company (GPC) has conducted an extensive re-review of the circumstances surrounding this event.
This re-review has included applicable drawings, MW0s, DRs, operator logs, control room indications, interviews with plant staff, and conversations with vendors.
This extensive review of this event has revealed new information -based, in part, on a reconstruction of existing data.
During this investigation (particularly through interviews with involved personnel) it has become apparent that overly conservative assumptions may have been made in arriving at the conclusion that the charcoal beds had been wetted.
Based on the re-review GPC has been unable to conclusively determine that the 1 A Standby Gas Treatment System (SGTS) charcoal beds were actually wetted as initially reported in Licensee Event Report (LER) 50-321/1986-007.
There may have been some limited localized wetting of the bottom portion of the charcoal but no actual massive wetting appears to have occurred.
Therefore, we can neither admit nor deny the existence of a violation.
However because the situation does need to be improved so that future events of this nature are avoided, GPC has taken several actions to improve the performance of plant staff.
The following discussion provides details of the situation and the corrective actions related to it.
BACKGROUND DISCUSSION:
When engineering personnel opened the 1A SGTS filter on March 11, 1986, they found approximately 2 inches of standing water in the bottom of the filter train charcoal bed compartment.
In addition, a supposed " water mark" was observed approximately 7 inches high on the inside wall of the filter cabinet.
The person assumed the standing water and the " water mark" were the result of a single fire protection deluge system actuation, and therefore assumed that the charcoal had been wetted.
This assumption was not based on any testing or physical measurement.
The charcoal beds were removed and discarded under the assumption that they had at one time been wet and were thus incapable of performing their intended function.
This replacement was done based on conservative decisions rather than technical information.
The initial investigation into this event was completed on March 19, 1986.
That investigation concluded that the most probable cause for charcoal having become " wet" was a leaking fire protection deluge valve which was discovered on November 24, 1985.
However, the investigation was performed under the assumption that the charcoal had been wet.
The 1361C E2-1 5/13/87 mm um
Georgia Power d ENCLOSURE 2 (Continued)
RESPONSE TO NOTICE OF VIOLATION 86-43-01 possibility of the charcoal not being wet was not adequately investigated.
This information was reported in Licensee Event Report (LER) 50-321/1986-007 with the conclusions that "the root cause of the noncompliance with Technical Specifications was a failure of the involved personnel (both licensed and non-licensed plant personnel) to recognize that a leaking drip check valve could be indicative of a leaking deluge valve" and "the root cause of the wet charcoal was apparently due to material failure in that the deluge valve's (lT43-F032A) seat was leaking enough to wet the downstream charcoal fil ter bed".
The recent re-evaluation has led to the conclusion that the initial assumptions made on March 11, 1986, and some of the information reported in the LER may have been conservatively reported.
Concerning the initial assumptions, plant personnel took conservative action by replacing all of the charcoal in the filter train as if it had been deluged.
However, two inches of standing water in the filter train is not a sufficient quantity to wet the charcoal.
At least seven inches of water would be necessary to wet the bottom half of the lowest charcoal trays.
As previously stated, a seven inch water mark was noticed on the filter train wall.
The time or cause of this " water mark" formation is not known.
Since there is no information to determine when the water mark was formed, we cannot confirm that it occurred as part of this event or much earlier in plant history.
We believe that the water found in the filter train did most probably result from the leaking deluge valve.
This being the case, only a portion of the bottom charcoal trays would have gotten wet, even if the water level reached the level indicated by the water mark.
The re-review has determined that a sample was removed from the charcoal discarded on March 11,1986, to determine the " operability" of the charcoal which was removed.
The test resul ts indicated that the charcoal sample had a radioactive methyl iodide removal rate of 99.991%.
However, the random sample taken was not from the potentially wetted region of the charcoal bed.
Thus, no testing of the potentially wetted charcoal was done.
On this basis, while we cannot rule out water puddling in the bottom of the filter train from a leaking deluge valve and wetting the lowest trays, we can conclude that the deluge valve did not " fire" and wet the entire charcoal bed.
REASON FOR THE VIOLATION:
The reason for the violation was inadequate attention to detail and not following through on the root cause by the people involved as discussed in the following paragraph.
The 1A SGTS was declared inoperable due to conservative assumptions made by personnel directly involved in fil ter train testing on March 11, 1986.
Investigations conducted at the time of the event did not determine the validity of the foregoing assumptions.
Personnel responsible for initially reporting this event did not independently veri fy all the information which they were provided.
Operations personnel who initially 1361C E2-2 5/13/87 7,73 g
Georgia Power A ENCLOSURE 2 (Continued)
RESPONSE TO NOTICE OF VIOLATION 86-43-01 identified the leaking deluge valve on November 24, 1985, did not consider the leak significant and thus did not associate the leak with potentially wet charcoal.
The operator knew that the purpose of a ball drip valve was to relieve seat leakage past a deluge valve.
The ball drip valve is intended to provide a flow path for seat leakage away from the fire protected component rather than towards it.
However, due to the physical piping arrangement of the 1 A SGTS filter train deluge valves, it is possible for seat leakage to flow both toward the drip valve and the filter train.
The operator was not aware of this arrangement on November 24, 1985.
However, he correctly initiated a MWO and tagged the leaking portion of the deluge system out of service.
CORRECTIVE STEPS WHICH HAVE BEEN TAKEN AND THE RESULTS ACHIEVED:
The actions taken to return the "l A" filter train to service are documented in the referenced LER.
Operations and Maintenance training programs were revised as a result of the LER to include instruction to the effect that a leaking fire protection deluge valve may be indicative of water damage to the protected component.
Organization changes have been implemented at the plant site which increase the level of management involvement in review of events such as the one cited in this report.
The Deficiency Control system. procedure (10AC-MGR-004-0S) has been revised to streamline the process for identification and resolution of deficient conditions.
That procedure revision has made plant personnel more familiar with the importance of promptly identifying deficiencies.
A deficiency card was introduced as part of this revision, making personnel more familiar with the deficiency procedure and providing a better vehicle (pocket size card) for plant personnel to promptly identify deficient conditions in the plant.
Emphasis on the importance of attention to detail has been placed at all levels of plant management.
CORRECTIVE STEPS WHICH WILL BE TAKEN TO PREVENT RECURRENCE:
Design Change Request (DCR) 87-93 has been written to change the fire protection deluge system for both unit's fil ter trains which contain charcoal filters, including SGTS, from automatic initiation to manual.
This DCR is scheduled for implementation in 1987 for Unit 1 and 1988 for Unit 2.
DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED:
Full compliance has been achieved.
1361C E2-3 5/13/87 mns m