ML20215C239
| ML20215C239 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 08/29/1986 |
| From: | Williams J TOLEDO EDISON CO. |
| To: | Norelius C NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 1-658, NUDOCS 8610100181 | |
| Download: ML20215C239 (14) | |
Text
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TOLEDO
%ma EDISON Docket No. 50-346 JOE VVILUAMS. JR Sarnor Vce Premdert-Nudear License No. NPF-3
{l$$M Serial No. 1-658 August 29, 1986 Mr. C. E. Norelius, Director Division of Reactor Projects United States Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137
Dear Mr. Norelius:
Toledo Edison has received Inspection Report 50-346/85040 (Log No. 1-1382) and the Notice of Violation (Log No. 1-1427) and provides the following response.
It should be noted that many of these nonconformances were discovered during Toledo Edison's System Review and Test Program (SRTP). The SRTP was established following the June 9, 1985 loss of feedwater event to review the history of systems important to the safe operation of the Davis-Besse Station. As discussed in the Davis-Besse Course of Action (C0A), Serial No. 1182, the reviews are intended to:
- 1) identify problems which may impact the ability of those systems to perform the necessary functions for safe operation of the plant; 2) identify the corrective actions necessary to resolve those problems; and 3) identify any special testing of the system that should be performed during restart. The program is also reviewing the scope of surveillance testing conducted and identifying additional testing which is necessary to assure systems will perform their intended functions.
As noted herein, the overall engineering capability at Toledo Edisen in support of Davis-Besse is being upgraded and will be an important part of avoiding further violations. This upgraded capability includes:
The formation of a Systems Engineering Group. The Systems Engineers j!g have assigned systems and are responsible for developing a detailed eno knowledge of their systems, including the design basis and surveil-lance requirements, oo
.onn An in-house design and analysis capability which minimizes the need amo for outside engineering services and ensures continuity and complete-
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$g ness of the design process for plant modification.
OQ 34 A configuration management program which captures and maintains the 3
design basis and as-built configuration of the plant.
4Q CDQ O THE TOLEDO EDISON COMPANY FOISON PLAZA 300 MADISON AVENUE TCLEDO. OHIO 43652 SEP 51986 ye.c p Sl*
Dockat No. 50-346 License No. NPF-3 Serial No. 1-658 August 29, 1986 Page 2 Violation I:
Technical Specifications (TS) Limiting Condition for Operation (LCO) 3.7.6.1 requires that two independent control room emergency ventilation systems (CREVS) be operable in Modes 1, 2, 3 and 4.
Technical Specification 1.6 defines operability and specifies as a condition for operability of a system that all auxiliary equipment required for the system or subsystem must be capable
.of performing its related support function.
Technical Specification 3.0.3 requires that when an LCO is not met the unit must be placed in a mode in which the specification does not apply by placing it in at least hot standby (Mode 3) within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, at least hot shutdown (Mode 4) within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and at least cold shutdown (Mode 5) within the subsequent 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, as applicable.
a.
Contrary to the above, from July 2,1977 to August 4, 1977, while the unit was in Modes 3 and 4, both trains of the CREVS were inoperable in that for both trains, both water and air cooled condensing units were inoperable. These units are-required for the CREVS to perform its intended function. The CREVS service water valve control circuits for both trains would not permit the valves to open, thereby preventing operation of the water cooled condensing units, and during this period when operation was attempted using 2
the air cooled condensing units, the refrigerant compressor motors of both trains would repeatedly I
trip on electrical overload. The unit was not placed l
in cold shutdown within the time required by TS l
(85040-01a,b) b.
Contrary to the above, for an indeterminant period of time, possibly since initial plant operation and until October 1985, both trains of the CREVS were inoperable in that the refrigerant compressor motors required for the CREVS to perform its intended function would repeatedly trip when the outside air tenperature was below 15 degrees F.
The unit was not placed in cold shutdown within the time required by TS LCO 3.0.3.
(85040-01a,b)
Docket No. 50-346 License No. NPF-3
. Serial No. 1-658 August 29, 1986 Page 3 1
Response
Acceptance or Denial of the Alleged Violation Toledo Edison acknowledges the alleged violation.
Reason for Violation i
The root cause of these_ conditions appears to be inadequate design / incomplete design verification testing during the plant preoperational startup phase.
These conditions continued to exist because the system design / design basis operational requirements were not fully understood. This translated into surveillance tests which failed to fully verify system operability.
It should be noted that the safety significance of having the CREVS inoperable during July 2 to August 4, 1977 is minimal since this time period was before initial criticality.
The System Review and Test Program identified that the solenoid valves chattered when the system was running with low refrigerant suction pressure. This would allow a bypass of refrigerant when the CREVS unit was in operation. When the system was idle, refrigerant migration through the solenoid valves to the air-cooled condensing unit also occurred and lowered the level of refrigerant in the water cooled condenser, causing it to 3
trip on low suction pressure when it started.
l During air cooled operation at low outside air temperatures the refrigerant compressor motor would trip. This was due to the temperature controller operating backwards, opening the damper and allowing overcooling instead of closing the damper, as the system required.
Corrective Actions Taken and Results Achieved i
Facility Change Request (FCR)85-265 has eliminated the flow i
switch interlock and installed a high pressure switch. The l
high pressure switch will change over operation to the air cooled condenser on high refrigerant gas pressure. This change will allow the CREVS to start and operate in the water cooled mode.
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Dockot No. 50-346 License No. NPF-3 Serial No. 1-658 August 29, 1986-Page 4 FCR 85-265 also modified the damper control circuitry, eliminating the use of temperature controllers and replacing them with refrigerant head pressure controllers. ~ This will provide a more accurate means of control since it will monitor the parameter that is being controlled. Closeout of this FCR is pending the completion of test procedure TP 850.75.
Higher rated overload protection was installed on August 4, 1977 by Startup Field Report (SFR) E771.
Surveillance Test procedure, ST 5076.01, " Control Room Emergency Ventilation Monthly Test" has been revised to include verification that the service water supply valves open automatically upon initiation of CREVS.
t FCR 85-222 has been implemented to replace the refrigerant solenoid valves and add check and stop valves at the interface of the water-cooled condensers and the air-cooled condensers. These modifications will eliminate the refrigerant migration problem.
Closeout of this FCR is pending the completion of test procedure TP 850.75.
Corrective Actions to be Taken to Avoid Further Violations Test Procedure (TP) 850.75 will test the CREVS functions important to safe plant operation, as identified by the SRTP and which are not adequately tested by the existing surveillance tests to ensure proper operation before criticality.
A Surveillance Test procedure will be written to provide continued periodic testing which will verify CREVS operability.
This new test will be based on the TP 850.75.
As stated previously, the overall engineering capability i
of Toledo Edison is being upgraded.
(
Date When Full Compliance Will Be Achieved Full compliance will be achieved with the modifications to the CREVS and verified by the successful completion of test procedure TP 850.75 prior to restart.
l The new Surveillance Test which will verify system operability will be in place six (6) months after restart.
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r Dockat No. 50-346 License No. NPF-3 Serial No. 1-658 August 29, 1986 Page 5 Violation II:
10 CFR Part 50, Appendix B, Criterion III, Design Control, as implemented by the Toledo Edison Nuclear Quality Assurance Manual (NQAM), Section 3, requires that measures shall be established to assure that applicable regulatory requirements and design bases are correctly translated into specifications, drawings, procedures, and instructions and that design changes shall be subject to design control measures commensurate with those applied to the original design.
a.
Contrary to the above, design changes which increased heat loads in the area cooled by the CREVS were not subjected to design control measures commensurate with those applied to the original design to verify that the increases were within the cooling capacity of the CREVS. Examples of some design changes which occurred during the period 1980-1983 include the installation of the Post Accident Indicating Panels, Post Accident Monitoring Equipment Racks, Anticipatory Reactor Trip System, and Safety Parameter Display System. As a result, with the additional heat loads, the design capability of the CREVS was exceeded.
(85040-02) b.
Contrary to the above, design control measures did not assure that design requirements were translated into specifications or drawings in that roof mounted air cooled condensing unit piping was not adequately protected from tornado missiles as described in the Davis-Besse Updated Safety Analysis Report.
(85040-01a, b)
Response
Acceptance or Denial of the Alleged Violation Toledo Edison acknowledges the alleged violation.
I Reason for Violation The root cause of the failure to consider the effects of additional heat loads on the CREVS appears to be inadequate initial review and design review prior to FCR implementation.
The root cause of not having the condensing unit piping l
adequately protected from tornado generated missiles is from not fully understanding the design basis and not having an complete design basis in the USAR.
Corrective Action Taken and Results Achieved Bechtel has completed a new heat load study which considered the physical configuration in the control room and determined the current existing heat load.
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D:ckst Ns. 50-346 License No. NPF-3 Serial No. 1-658 August 29, 1986 Page 6 Heat load testing was performed as part of TP 850.75. The results of this testing indicate that no load shedding, except the station computers, is required.
FCR 85-274 upgraded the capacity of the CREVS from 66,750 BTU /hr. to 120,000 BTU /hr.
The water-cooled condenser is the guaranteed source of cooling for the system. The water-cooled unit is protected against all postulated hazards. However, in the event of an earthquake in which the line from the lake to the forebay may be lost, the service water temperature in the forebay could rise to above 110*F.
At this high temperature, the water-cooled condensor may not be operable and the air cooled unit must be placed in operation. The air-cooled unit is qualified for all postulated accidents except a tornado. A tornado and an earthquake are not postulated in the design basis to occur simultaneously and therefore the coolant lines for the air cooled subsystem do not need to be protected.
In the event of a tornado generated missile rupturing the coolant lines on the roof, the cooling function being performed by.the water-cooled subsystem of the CREVS would not be affected since the portion of the system on the roof is now isolated from the remaining system by the solenoid valves and the check valves installed by FCR 85-222 (see response to Violation I) until the air cooling function is actuated.
The USAR will be revised to reflect the actual design basis for the CREVS. This will include revisions to Table 9.4-1 " Single-Failure Analysis - Control Room Emergency Ventilation System" and Table 9.4-2 " Control Room Emergency Ventilation System Heat Loads".
Corrective Actions to be Taken to Avoid Further Violations The plant modification process and procedures are being reviewed to ensure heat loads are considered for any modifications to the plant. Procedure revisions will be intiated as they are identified during this review.
Date When Full Compliance Will Be Achieved Full compliance will be achieved with the next revision of the USAR in June 1987.
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Docket No. 50-346 License No. NPF-3 Serial No. 1-658
. August 29, 1986 Page 7-Violation III: 10 CRF Part 50, Appendix B, Criterion XI, Test Control, as implemented by NQAM Section 11, requires that testing to demonstrate that structures, systems, and components will perform satisfactorily if service is identified and performed in accordance with written test procedures which incorporate the requirements contained in applicable design documents.
a.
Contrary to the above, at the time of the inspection the operational surveillance testing program (ST 5076.01.06) did not incorporate the applicable design requirements to demonstrate that the CREVS would operate as intended. The testing program failed to identify that the control dampers for the air cooled condensing units operated improperly and that the control circuits for the service water supply valves prevented opening of the valves.
(85040-04a) b.
Contrary to the above, in June 1979, after replacement of a control room airtight door (No. 509) without its I
sealing gaskets, work control documents had not identified that post-maintenance testing was necessary j
to verify that the required leak tightness of the control room was maintained.
(85040-04b)
Response
Acceptance or Denial of the Alleged Violation Toledo Edison acknowledges the alleged violation.
j Reason for Violation i
As stated in the response to Violation I, the root cause of these conditions appears to be inadequate design / incomplete design verification testing.
These conditions continued to exist because the system design / design basis was not fully understood. This translated into sarveillance tests which failed t, fully verify system operability.
The root cause of not identifying that post maintenance testing was necessary for door 509 appears to be inadequate technical review of the FCR which replaced the existing door. The FCR did not require the new bullet-proof door to be air-tight. This inadequacy also included the lack i
of appropriate post modification testing.
I Corrective Action Taken And Results Achieved i
FCR 85-265, as discussed in Violation I, will allow the CREVS to start and operate in the water-cooled mode, and will provide a more accurate means of control for the i
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Dockat No. 50-346
. License No. NPF-3 Serial No. 1-658 August 29, 1986 Page 8 FCR 85-299 has installed a bypass switch which allows the damper actuators to be continuously energized during subzero temperatures. Closeout of this FCR is pending completion of TP 850.75.
FCR 85-308 has been initiated to install the the sealing gaskets on Door 509.
System Procedure SP 1104.69 " Control Room Emergency Ventilation System" has been revised to require energizing the damper actuators prior to reaching 0 F.
AD 1844.11, " Post Maintenance Testing Requirements" has been implemented and requires testing af ter any maintenance or modification which may affect the capability of any system, component or equipment to perform its design function.
Corrective Actions To Be Taken To Avoid Further Violations TP 850.75 will test the CREVS functions important to safe plant operation, as identified by the SRTP, which are not adequately tested by the existing surveillance tests before critical-ity. This includes the ability to verify that the required leak tightness of the control room is maintained.
A Surveillance Test procedure will be written to provide l
continued periodic testing which will verify CREVS operability.
This new test will be based on test procedure TP 850.75.
As stated previously, the overall engineering capability of Toledo Edison is being upgraded.
Date When Full Compliance Will Be Achieved Full compliance will be achieved when the CREVS surveillance test is issued six months after restart.
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D:ckst Ns. 50-346 License No. NPF-3 Serial No. 1-658 August 29, 1986 Page 9 Violation IV:
10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, as implemented by NQAM Section 16 and Administrative Procedure AD 1807.10, requires that measures be established to assure that conditions adverse to quality, such as failures, malfunctions, deficiencies, deviations, defective material and equipment, and nonconformances are promptly identified and corrected.
a.
Contrary to the above, on February 1, 1984, a Facility Change Request 84-0054 identified a condition which prevented the CREVS from performing its cooling function in cold weather; however, corrective action was not taken until October 1985.
b.
Contrary to the above, on May 17, 1980 the licensee was informed by a letter from a contractor that control room door number 509 did not have required airflow sealing gaskets; however, corrective action was not taken by the licensee until February 1986.
(85040-05b)
Response
Acceptance or Denial of the Alleged Vio)ation Toledo Edison acknowledges the alleged violation.
Reason for Violation The reason these items were not identified in a more timely manner appears to have been inadequate training of people in dealing with conditions adverse to quality and I
not having a definitive method for identifying postulated problems.
Corrective Action Taken and Results Achieved FCR 85-222 and FCR 85-265 have corrected the conditions identified by FCR 84-0054 (see response to Violation I).
I FCR 85-308 has been initiated to install the gaskets on Door 509.
Procedure NMP-QA-702, " Potential Condition Adverse to l
Quality Reporting" became effective May 26, 1986.
i Training on this procedure has been performed for Mission personnel, and the procedure has been issued as required reading. This procedure provides a recognized l
path for proper identification and resolution of problems.
This ensures that knowledgeable individuals are aware of i
problems and that necessary corrective actions are implemented based on the problem's significance.
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Dockrt No. 50-346 License No. NPF-3 Serial No. 1-658 August 29, 1986 Page 10 Corrective Actions to be Taken to Avoid Further Violations As stated previously, the overall engineering capability of Toledo Edison is being upgraded. The responsible Systems Engineer will maintain cognizance of those FCRs involving their assigned systems. This includes providing assistance in resolution of maintenance problems (trouble-shooting and identification of appropriate post-maintenance testing).
Date When Full Compliance Will Be Achieved Full compliance will be achieved upon completion of test procedure TP 850.75.
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- Docket No. 50-346 License No. NPF-3 Serial No. 1-658 August 29, 1986
~ Page 11 Violation V:
Technical Specification 6.8.1.a requires that written procedures shall be established, implemented and maintained covering the activities recommended in Appendix A of Regulatory Guide 1.33, November, 1972. Regulatory Guide 1.33 specified that procedures are required for the operation of the auxiliary building heating and ventilation system.
The.
CREVS is a part of the auxiliary building heating and l
ventilation system.
a.
Contrary to the above, at the time of the inspection, the licensee had not established a procedure for elimination of nonessential heat loads in the control room area in the event that the CREVS allowed the control room temperature to reach its upper limit.
(85040-03a) b.
Contrary to the above, at the time of the inspection,
-the licensee had not established a procedure to inform personnel >that removing the air or water cooled CREVS condensing units from service would degrade the i
operability of the CREVS.
(85040-03b) 1
Response
Acceptance or Denial of the Alleged Violation Toledo Edison acknowledges the alleged violation.
Reason for Violation Initial testing indicated that Control Room load shedding procedures were not required. Toledo Edison acknowledges the violation since the need for load shedding was not evaluated when plant modifications were installed which increased the heat load in the control room. The root cause appears to be inadequate initial review and design review prior to FCR implementation.
It was not identified until mid-September, 1985 that both air-cooled and water-cooled modes were required. The root cause of this portion of the violation appears to be, as stated in the response to Violation I, that the system design / design basis was not fully understood.
l Corrective Action Taken And Results Achieved Heat load testing was performed as part of TP 850.75. The results of this testing indicate that no load shedding beyond the station computers is required.
Draft Procedure AB 1203.42 "CREVS Load Shedding" provides successive load shedding steps to be taken upon continued i
temperature increases. This procedures will provide additional assurance of temperature limiting capability.
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D:cket Ns. 50-346 License No. NPF-3
' Serial No. 1-658 August 29, 1986 Page 12 7
Corrective Actions To Be Taken To Avoid Further Violations The design basis in USAR Section 9.4 will be revised.
This includes a revision to Table 9.4-2 " Control Room Emergency Ventilation System Heat Loads."
As stated previously, the overall engineering capability of Toledo Edison is being upgraded.
Date When Full Compliance Will Be Achieved The USAR revision will be included in the 1987 update of the USAR.
AB 1203.42 "CREVS Load Shedding" will be in place prior to restart.
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Dscket No. 50-346 t*
License No. NPF-3 Serial No. 1-658 August 29, 1986 Page 13 Violation VI:
10CFR 50.72(b)(ii)(B), requires that a licensee notify the NRC as soon as practical and in all cases within one hour of the occurrence of any condition or event that results in the nuclear power plant being in a condition outside the design basis of the plant.
Contrary to the above, February 1,1984, the licensee 4
identified that both trains of the CREVS were inoperable when outside temperatures were below 15* to 20 F and therefore resulted in the plant being in a condition j
outside the plant's design basis. The licensee did not report the condition to the NRC until November 1, 1985.
(85040-06)
Response
Acceptance or Denial of the Alleged Violation Toledo Edison acknowledges the alleged violation.
Reason for Violation 4
The root cause for not reporting the inoperability of the CREVs in a more timely manner appears to be, as stated in the response to Violation I, that the system design /
design basis operational requirements were not fully understood. A contributing cause has been determined to be the lack of a definitive method for identifying and reporting potential problems.
1 Corrective Action Taken And Results Achieved LER 85-018-00 " Control Room Emergency Ventilation System-Inoperable Cooling" was submitted November 1, 1985.
FCR 85-222 and FCR 85-265 have corrected the conditions l
identified (see response to. Violation I).
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Procedure NMP-QA-702 " Potential Condition Adverse to Quality (PCAQ) Reporting" became effective on May 25, 1986.
l This procedure requires the Shift Supervisor to review each PCAQ immediately after generation. The plant Technical Support Department then reviews each PCAQ for reportability concurrence and form completion. The Technical Support Department submits the PCAQ to a PCAQ l
Review Board. The Board normally reviews PCAQs on the next working day unless a special Board is convened.
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1 Dsckst No. 50-346
'j License No.'NPF Serial No. 1-658' August 29, 1986 Page 14 Corrective Actions to be taken to avoid further Violations As stated previously, the overall engineering capability of Toledo Edison is being upgraded. The responsible Systems Engineer maintains involvement in reportability determinations (PCAQ, LERs, 10CFR21 reports).
Date When Full Compliance Will Be Achieved Full compliance has been achieved by the actions described above.
Very truly yours,
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cc: DB-1 NRC Resident Inspector e
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