ML20153G618
| ML20153G618 | |
| Person / Time | |
|---|---|
| Site: | Portsmouth Gaseous Diffusion Plant |
| Issue date: | 09/23/1998 |
| From: | Jonathan Brown UNITED STATES ENRICHMENT CORP. (USEC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 70-7002-98-11, GDP-98-2041, NUDOCS 9809300139 | |
| Download: ML20153G618 (6) | |
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l USEC A Global Energy Company r
September 23,1998 GDP-98-2041 United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001 Portsmouth Gaseous Diffusion Plant (PORTS)
Docket No. 70-7002 Revised Reply to Notice of Violation (NOV) 70-7002/98011-03 On August 31,1998, USEC submitted a reply to the subject NOV which concemed a failure to take corrective actions to prevent spurious safety system actuations (see USEC letter GDP 98-2040).
USEC is submitting this revised response to NOV 98011-03 to provide additional clarification regarding this violation. Changes to the original NOV reply are indicated by margin bars on the right-hand side of the document.
USEC requests NRC replace Enclosure 1 of our previous submittal with the enclosed revised NOV response. Also, replace the commitments made for NOV 98011-03 in Enclosure 4 of our previous submittal with the commitments listed on Enclosure 2 l
attached. Unless specifically noted, the corrective actions specified in each enclosure apply solely to PORTS.
If you have any questions regarding this submittal, please contact Dave Waters at (740) 897-2710.
Sincerely,
. Morris Brown General Manager Portsmouth Gaseous Diffusion Plant
Enclosures:
As Stated cc:
NRC Region III Office NRC Resident Inspector - PORTS NRC Director, Office of Enforcement 9809300139 900923 PDR ADOCK 07007002 A
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t 110. Box 800, Portsmouth, OH 45661 Telephone 740-897-2255 Fax 740-897-2644 http://www.ustc.com Offices in Livermore, CA Paducah, KY Portsmouth, OH Washington, DC
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GDP 98-2041 Page1of4 UNITED STATES ENRICIIMENT CORPORATION (USEC)
SUPPLEMENTAL REPLY TO NOTICE OF VIOLATION (NOV) 70-7002/98011-03 Restatement of Violation 10 CFR 76.93, " Quality Assurance," requires that the Corporation shall establish, maintain, and execute a quality assurance prograrn satisfying each of the applicable requirements of American Society of Mechanical Engineers (ASME) NQA-t-1989," Quality Assurance Program Requirements for Nuclear Facilities."
ASME NQA-t-1989, Basic Requirement 16," Corrective Action," states that conditions adverse to quality (CAQs) shall be identified promptly and corrected as soon as possible.
C8 of Appendix A of XP4-BM-CI1002," Problem Report Screening Process," lists inadequate work instructions as a specific example of a CAQ.
Contrary to the above, the certificatee did not take action to prevent the spurious containment isolation of Autoclave No. 3 in the X-344 Building on June 30,1998. The certificatee's intended corrective action to prevent recurrence of an August 1997 event, to add a precaution to the work package to isolate Autoclave No. 4 during a maintenance activity, was not impiemented.
USEC Response I.
Background
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i The August 1997 evcc.t occurred while electricians were making repairs to Autoclave No.
- 3. In the course of the repair, the electricians opened the breakers inside of the EPTAK control cabinet. When the breaker for the EPTAK Input / Output (1/0) boards was opened, the EPTAK controller shutdown and placed Autoclave No. 4 in containment. A Problem Report (PR PTS-97-7051) was written to document this event. As a corrective action to this event, Operations personnel issued a memorandum which stated, in part, that "when developing work packages that consist of troubleshooting or repairs to the control panels or i
EPTAK I/O boards, an instruction should be included in the work package to turn the controller off-line on the autoclave being repaired." This guidance is included in the procedure for replacing the EPTAK I/O modules for Autoclave No. 3 and 4 in the X-344 Building.
The June 30,1998, event occurred due to a spurious closure of the autoclave containment valves leading to a high condensate level alann. It was initially thought that the containment i
isolation was due to a short or open circuit which resulted from electrical maintenance troubleshooting activities on Autoclave No. 4. Electricians were searching for the cause of I
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l GDP 98-2041 Page 2 of 4 fuses blowing in the Autoclave No. 4 hydraulic control panel. While lifting and landing control level wires for short/ ground detenninations, Autoclave No. 3 went into containment isolation. The troubleshooting activity was later repeated in an attempt to validate our initial speculation. Ilowever, we could not reproduce the containment isolation of Autoclave No.
3.
USEC has determined that the corrective action from the August 1997 event was not needed for the troubleshooting that was being performed when the June 30,1998, event occurred.
The individuals involved in planning and reviewing this activity were aware of the Operations memorandum when developing the troubleshooting work package and appropriately concluded that this precaution did not apply to this activity. This detennination was based on the knowledge that troubleshooting of the autoclave hydraulic control panels l
cannot cause a loss of power to the autoclave control panels or EPTAK I/O boards.
Furthermore, Autoclave No. 4 was in a shutdown condition when the troubleshooting of the hydraulic control circuits was perfonned.
II.
Reason for the Violation USEC has detennined that the root cause of the autoclave containment isolations that have l
been experienced since June 30,1998, was the malfunctioning of the EPTAK CPU module l
and subsequent failure of the replacement CPU module. PORTS has experienced spurious l
EPTAK CPU halts and subsequent autoclave containment isolations between mid-August l
and early September 1998. These events occurred both while the autoclaves were in l
operation and while shutdown. While these isolations are undesirable from an operational l
standpoint, they do not place the plant in an unsafe condition since the isolation causes the l
autoclave to be placed in containment.
l A contributing cause of the autoclave containment isolations was the failure to develop a l
routine preventative maintenance (PM) task for the EPTAK system. The failure to perform l
a routine PM task on the EPTAK system may have resulted in spurious electronic transients l
caused by corrosion, dirt, vibration, and thermal cycling. Additionally, this system is within j
a "Q" boundary as described in Section 3.8.1.4 of the SAR. USEC has reviewed the closure l
package for Compliance Plan issue 24 and determined that the action to develop a PM for the EPTAK system was closed based on the existence of surveillance procedures which test l
the safety system function of the EPTAK system. This methodology uses equipment l
condition monitoring to determine when maintenance should be performed, llowever, these l
surveillance procedures do not provide fbr a routine PM task to be performed on the EPTAK l
system.
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GDP 98-2041 j
Page 3 of 4 III.
Corrective Actions Taken and llesults Achieved 1.
Electronic Maintenance replaced EPTAK components as specified by the vendor's manual. Post maintenance testing of Autoclave No. 3 was successfully performed l
on August 20,1998, and the autoclave was declared operable. The autoclave then successfully completed a product transfer operation with no EPTAK CPU halts.
2.
Post maintenance testing of Autoclave No. 4 was successfully performed on August 22,1998, and the autoclave was declared operable. Subsequently, the autoclave successfully completed a product transfer operation with no EPTAK CPU halts.
3.
Power line filtering eqtJoment was installed on the incoming line for the EPTAK system on August 26,1998, in order to prevent electrical transients from causing EPTAK CPU halts.
4.
On August 31, 1998, another EPTAK CPU halt was experienced and another l
extensive troubleshooting elTort began. Vendor manual recommendations for l
l proceeding with the troubleshooting process were followed. This process suspected l
the EPTAK CPU module as the source of the malfunction. The CPU module was l
replaced on September 10,1998, and the EPTAK began to operate r.ormally. No l
malfunctions have been encountered during the subsequent six day testing period.
l A statistical analysis of the failure intervals experienced show a 99.5% probability l
of not experiencing another failure beyond the six days of continued EPTAK l
operation.
l 5.
Also, the EPTAK grounding system was modified in accordance with the original l
manufacturer's installation manual on September 16, 1998. This action should l
eliminate any potential concern for degraded grounding due to the age of the system and minimize the effects of electrical transients on system operation.
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6 USEC is currently performing a review of the adequacy of the closure of Compliance Plan issues at PORTS.
IV.
Corrective Actions to be Taken l
1.
A PM program for the EPTAK sptem and the other autoclave programmable logic l
controllers (PLCs) will be established and implemented for operable autoclaves by l
November 20,1998.
2.
Engineering will review other plant safety system equipment programmable logic controllers for adequacy of their PM program by December 15,1998. Subsequently.
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l GDP 98-2041 Page 4 of 4 any PM program revisions deemed necessary will be established and implemented l
by March 5,1999.-
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By February 15,1999, Engineering will review the PMs developed for Q system l
components that specify sureillance procedures as the PM task to ensure other j-
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routine PM tasks are not needed.' Subsequently, any PM program revisions deemed l
necessary will be established and implemented by August 20,1999.
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V.
Date of Full Compliance i
l Full compliance was achieved on September 16,1998, when the EPTAK CPU module was l
replaced and exhibited satisfactory operation.
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GDP 98-2041 Page1ofI List of Commitmentsi NOV 70-7002/98011-03 1
l 1.
A PM program for the EPTAK system and the other autoclave programmable logic controllers (PLCs) will be established and implemented for operable autoclaves by l
November 20,1998.
2.
Engineering will review other plant safety system equipment programmable logic controllers for adequacy of their PM program by December 15,1998. Subsequently, any PM program l
revisions deemed necessary will be established and implemented by March 5,1999.
l 3.
By February 15,1999, Engineering will review the PMs developed for Q system components l
that specify surveillance procedures as the PM task to ensure other routine PM tasks are not l
needed. Subsequently, any PM program revisions deemed necessary will be established and l
implemented by August 20,1999.
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' Regulatory commitments contained in this document are listed here. Other corrective
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actions listed in this submittal are not considered regulatory commitments in that they are either statements of actions completed, or they are considered enhancements to USEC's investigation, procedures, programs, or operations.