ML20046C768
| ML20046C768 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 08/05/1993 |
| From: | Horn G NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9308120081 | |
| Download: ML20046C768 (5) | |
Text
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4 GENERAL OFFICE G7*
M P O BOX 499. COLUMBUS. NEBRASKA 68602-0439
_M TELEPHONE (402) 564-8561 a) Nebraska Publ=c Power D*str*ct-. - - - - - -. - -
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August 5,
1993 U.
S.
Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555
Subject:
NPPD Response to Inspection Report 50-298/93-19 (Reply to a Notice of violation)
Gentlemen During an NRC inspection conducted on April 25 through June 5, 1993, certain licensed activities were identified as being in violation of NRC requirements.
The first violation concerned some 250 VDC battery cells where electrolyte levels were slightly above the maximum level indication mark.
The second violation was in regard to two fuel assemblies that were loaded into the reactor core without having all control rods fully inserted. The following is a restatement of the violations and our responses in accordance with 10 CFR 2.201.
STATEMENT OF VIOLATION 10 CFR 50, Criterion V, Instructions, Procedures, and Drawings, states that activities affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings.
Instructions, procedures, or drawings shall include appropriate quantitative or qualitative acceptance criteria for determining that important activities have been satisfactorily accomplished.
Technical Specification Surveillance 4.9.A.4.b.1 states that the electrolyte level of each connected cell is between the minimum and maximum level indication marks, to be verified every quarter with the actual values measured and logged.
Maintenance Work Request 93-1855 was implemented to adjust electrolyte levels in safety-related 250 VDC Batteries A and B, as necessary, on May 7,
- 1993, because of low electrolyte level.
Contrary to the above, adjusting the electrolyte level on safety-related 250 VDC Batteries A and B on May 7, 1993, was not prescribed by instructions appropriate to the circumstances in that Maintenance Work Request 93-1855 did not include instructions to determine that safety-related 250 VDC Battery electrolyte level was between the maximum and minimum level indication marks.
On May 17, 1993, 6 cells in the A 250 VDC battery and 11 cells in the B 250 VDC battery were found with electrolyte levels above the maximum level indication mark.
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Documeht Control Desk August 5, 1993 Page 2 This is a Severity Level IV violation (298/9319-01)(Supplement I).
REASON FOR THE VIOLATION on May 5, 1993, surveillance Procedure 6.3.15.1, 125V/250V-Station and Diesel Fire Pump Battery Quarterly Check, was performed. As a result, some battery cells in both the 125 VDC and 250 VDC battery banks were identified as having i
low levels.
In this case, the levels ranged from approximately 1/8 to 3/8 inches below the maximum mark, with the majority of the cells being at the maximum mark.
The minimum and maximum marks are approximately 1 inch apart.
It is common practice at CNS to initiate a Maintenance Work Request (MWR) to add water to battery cells whenever any cell level decreases to approximately mid-level as a means of controlling and documenting the work activity for historical purposes.
MWR (93-1855) was written to " Adjust electrolyte levels as necessary" in the 125 VDC and 250 VDC batteries, and the work was performed on May 7, 1993.
It is important to note that the highest level recorded on May 17 for these 17 cells was 1/16 inches above the maximum mark.
This situation was rectified in accordance with the work item before declaring the batteries operable.
The evaluation of the occurrence identified the cause for the electrolyte in some cells to be above the maximum mark as parallax error when reading the cell levels on May 5 and attention to detail during the addition of water to the electrolyte on May 7, 1993.
CORRECTIVE STEPS TAKEN AND RESULTS ACHIEVED Immediately after the cendition was identified,'the Shift Supervisor declared both 250 VDC batteries inoperable and suspended fuel movement. Maintenance personnel performed an inspection of the batteries, identified and recorded levels of the 17 cells with levels above the maximum mark, then removed the excess electrolyte from those cells. The levels were lowered to just below the maximum mark.- The 250 VDC batteries were subsequently declared operable.
CORRECTIVE STEPS TO BE TAKEN TO AVOID FURTHER VIOLATION A Technical Specifications (TS) change request was submitted by NPPD.on February 25, 1992, and approved on. July 7, 1993, which' modified the TS to clarify the performance criteria and surveillance requirements for the DC
. power systems, adding new specifications and surveillance' requirements, consistent with BWR/4 Standard Technical Specifications. The new upper level limit is $1/4 inches above.the maximum level indication mark, with an allowable value of "not overflowing," in accordance with IEEE 450.(IEEE Recommended Practice for Maintenance, Testing, and Replacement-of large Lead Storage Batteries for Generating Stations and Substations).
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Document Control Desk August 5, 1993 Page 3 In considering the cause of this violation, the District concluded, based on the required craft knowledge levels, that the current practice of refilling the battery cella via Maintenance Work Request (without special instructions or independent verification) is within the skill of the craft. The level margin provided by the TS amendment will provide the necessary buffer to prevent exceeding the prescribed level limit as a result of parallax errors in the future. The incident was also discussed with Electrical Maintenance personnel as part of the required corrective action to sensitize the craft with the issues of parallax and width of the cell indication markings, the requirement for exact compliance with technical specifications, and the importance of attention to detail in performing all maintenance work.
In addition, although not a part of the corrective action, the Technical Specifications amendment will be presented as part of the Electrical Maintenance Training Program.
DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED NPPD is currently in full compliance.
STATEMENT OF VIOLATION i
Technical Specification 3.10.A.2 otates that fuel shall not be loaded into the reactor core unless all control rods are fully inserted or unless the spiral unload / reload technique is used.
Contrary to the above, on May 28, the licensee loaded two fuel assemblies (YJO358 and YJO349) into the reactor core without having all of the control rods fully inserted and the spiral unload / reload technique was'not used.
Control Rod 14-39 was fully withdrawn.
This is a Severity Level IV violation (298/9319-02) (supplement I).
REASON FOR VIOLATION l
Following the completion of fuel loading and during control rod drive friction
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testing, it was determined that a fuel support piece may be misaligned.
In order to reposition the fuel support piece, four fuel assemblies had been removed and the associated control' rod withdrawn. The detailed in-core movement instructions to. accomplish this task were subsequently revised when it became necessary to remove two additional fuel assemblies in adjacent cells to allow the removal tool greater access to the fuel support piece in question. The revision to these detailed instructions did not recognize the Technical Specifications requirement to have all control rods fully inserted prior to loading fuel (unless the spiral unload / reload technique is used).
Upon removal of the fuel support piece to the fuel pool for inspection, the two additional fuel assemblies that had been removed for improved access were reloaded into the adjacent cells, a violation of Technical Specifications.
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Document Control Desk August 5, 1993 Page 4 CORRECTLYE STEPS TAKEN AND THE RESULTS ACHIEVED The error was corrected by fully inserting the withdrawn control rod per the subsequent steps in the revised instructions. This placed CNS in compliance with Technical Specifications.
The Reactor Engineer and Licensed Operators responsible for preparation and=
review of the revision to the fuel motement instructions were counseled and a copy of LER 93-023, which initially reported this violation, was routed to all licensed operators to ensure they are aware of the circumstances surrounding this event.
A review of applicable CNS procedures determined that there was insufficient guidance or warning provided to personnel performing revisions to fuel movement instructions and that enhancements would be necessary. Reactor Engineering and Operator training program reviews determined that-onhancements to these training programs are also needed with additional emphasis placed on Technical Specification 3.10.A.2 and its requirement for full insertion of all control rods.
CORRECTIVE STEPS WHICH WILL BE TAKEN TO AVOID FURTHER VIOLATIONS Procedure 10.21, Special Nuclear Materials and Accountability Instructions will be revised to emphasize the Technical Specification 3.10.A.2 requirements for fuel movement and control rod positioning,_with special focus on performance of on-the-spot revisions. The procedure will be' revised by December 31, 1993.
The Reactor Engineering pre-outage refueling training lesson plan will be revised to clarify and emphasize Technical Specification 3.10.A.2 requirements for fuel movement and control rod positioning. The lesson plan will also focus on the performance of on-the-spot revisions of control rod movement instructions and this violation. The lesson plan will be upgraded by December 31, 1993. This revised lesson will be. presented prior to the next refueling outage.
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The Operator pre-outage refueling training lesson plan was revised on June 25, 1993. The revision incorporated Technical Specification 3.10.A.2 requirements for fuel movement and control rod positioning, the circumstances resulting in LER 93-023 and Procedure 10.25.1,-Refueling - Core Reload. This~ revised lesson plan will also be presented prior to the next refueling ~ outage.
DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED NPPD is currently in compliance with the requirements stated in the-violations.
The follow-up actions identified above, with the exception of the reactor engineering and operator pre-outage refueling training, will be completed by December 31, 1993. The reactor engineering and operator pre--
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Document Control Desk Eugust 5, 1993 Page 5 h
outage refueling training will be completed prior to the next refueling outage.
should you have any questions regarding this matter, please contact me, b
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cM Horn Nu M ar Power Group Manager GRH/VWS/RWK cml-51H cca Regional Administrator USNRC - Region IV NRC Resident Inspector Cooper Nuclear Station b
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