IR 05000387/1988018
| ML17156A937 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 11/16/1988 |
| From: | Anderson C, Julio Lara, Woodard C NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML17156A935 | List: |
| References | |
| 50-387-88-18, 50-388-88-21, NUDOCS 8811300312 | |
| Download: ML17156A937 (13) | |
Text
U.S.
NUCLEAR REGULATORY COMMISSION
REGION I
Report No.
50-387/88-18; 50-388/88-21 Docket No.
50-387; 50-388 License No.
. Pennsylvania Power and Light Company 2 North Ninth Street Al 1 entown, Pennsyl vani a 18101 Facility Name:
Inspection At:
Susquehanna Steam Electric Station Units 1 and
Berwick, Pennsylvania Inspection Conducted:
September 28-30, 1988 Inspectors:
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. Woodard, Reactor Engineer C 0
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..F. Lar, eactor Engineer Approved by:
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. Anderson, Chief, Plant Systems Section p'
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$Y date Ins ection Summar
Routine announced ins ection on Se tember 28-30 1988 Re ort Nos.
50-387/88-18 and 50/338/88-21
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dE Safeguards Features actuations in which the Reactor Water Cleanup (RWC)
System was isolated when a large Unit
pump motor was started.
Inspection and Evaluation of licensee reported loss of redundancy and isolation for Unit 2 between Division I and II 125 volt D-C power due to inadvertent electrical cross ties between the two systems through the Reactor Recirculation Pump (RCP)
ATWS trip circuit.
Review of the licensees surveillance procedures used to control/assure the emergency diesel generators fuel, jacket water and lube oil.
Results:
One violation, one licensee identified violation and one unresolved item were identified.
The unresolved item involves problems with the Riley instrumentation modules in the RWCU circuity.
In the licensee identified violation, the licensee reported performing a plant modification under an approved design modification package which provided for new power supplies wiring which crosstied the Unit 2 Division I and Division II 125 volt D-C power supplies.
The modification did not provide for the removal of the old wiring to eliminate the crosstie.
The NRC identified violation involved the fact that the licensee's purchase documentation for emergency diesel generator fuel involves ASTM specification requirements in order to assure the proper fuel.
However, the fuel is supplied, accepted, and used without confirmation that it meets specification requirements.
8'1300312 8"-:1117 PDR ADOCK 05000387
DETAILS 1.0 Persons Contacted Penns lvania Power and Li ht Com an
- J. Blakeslee, Assistant Plant Superintendent
"R. Prego, gA Supervisor, Operations
- R. -Sheranko, Sr. Results Engineer
"B. Veazie, Sr. Results Engineer T.
C. Dalpiaz, Technical Supervisor R. Wehry, Compliance Engineer G. Butler, Supervisor, Maintenance
" T. Slusser, Technical Procurement Analysis J. Wolfer, Senior Chemist N. Coddington, Senior Project Engineer, Licensing E.
Heckman, Supervisor Licensing T. Per'kins, Systems Engineer R. Yasenchak, IEC Engineer D. Roth, Compliance Supe~visor.
, C. Angione, Design Engineer U.S. Nuclear Re viator Commission
- J. Stair, Resident Inspector F. Young, Senior Resident Inspector 2.0
- Denotes those present at the exit meeting on September 30, 1988.
Sco e of Ins ection 3.0 This inspection was conducted to review the cause of recent unplanned Engineered Safety Feature (ESF) actuations in which the Unit 2 Reactor Water Cleanup System was isolated when large Unit 1 electric'al pump motors were'tarted.
In addition, a review was made of the licensee Non-Conformance Report and Safety Evaluation covering a Unit 2 plarit modification in which the Division I and Division II 125 volt D-C power supplies were crosstied and left in this condition following the modification.
Also, an independent inspection was made of the licensee's procedures and controls of the emergency diesel generators fuel, jacket water, and lubricating oil.
Rile Tem erature Modules in Unit 2 RWCU S stem (Module 52055)
On August 4, 1988, the licensee submitted to the NRC, pursuant to
CFR 50.73(a)(2)(iv),
Licensee Event Report 88-012-00.
This report documented three similar events over a two week period of time which resulted in unplanned Engineered Safety Feature actuations.
The Unit 2 Reactor Water Cleanup System (RWCU) was isolated during each event
whenever a large Unit 1 induction pump motor was started.
Details of these ESF actuations are documented in the NRC.report 50-387/88-12 and 50-388/88-15.
The licensee evaluated the causes of the ESF actuations and determined that a problem existed with the steam leak detection Riley temperature modules which were installed during the Unit 2 refueling outage.
In response to the experienced RWCU isolations, the licensee initiated a
review of the operation of the temperature modules.
This included a
review of the voltage transients which would be experienced at the Unit 2 Riley module panels during large induction motor starts in Unit l.
Licensee actions and inspector observations are described below.
During past routine replacement of some Riley temperature modules, the licensee observed slight variations in the circuit cards.
Subsequent discussions with the manufacturer revealed that the original module design had undergone various modifications and therefore some of the, installed modules indi'cate slight circuit differences.
Information as to the extent of the modification was not available to the inspectors at the time of this inspection.
In an 'effort to have identical and up-to-date temperature modules, the licensee decided to replace all of the installed Unit 2 Riley temperature modules with the manufacturer
'
newest version.
(Unit 1 Riley temperature modules have not been replaced similarly.)
All the Riley modules, including replacements with modifications, have the same part number.
The Riley modules are designed to operate at a voltage of 120 VAC + 10/
(108 to 132 V).
In evaluating the causes of the RWCU isolations, the licensee measured the power feed to a Unit 2 Riley module panel upon a
Unit 1 RHR pump start.
Review of the visicorder strip chart indicated an initial voltage of 130 VAC at the module panel.
When the RHR pump started, the panel voltage dropped to 115 VAC.
This voltage spike was anticipated and is within the module operating voltage envelope.
Since 115 VAC is higher than the lowest voltage allowed for the Riley module, it should not affect the operation of the module.
However, during this pump start, the Riley module tripped.
This anomaly therefore raised questions as to potential problems with the newest Riley module version.
Bench testing of the new Riley modules indicated that they are susceptible to tripping when subjected to voltage dips.
The tests indicated that when a voltage dip is experienced at the inputs to the module panel, it results in lowering the temperature trip setpoint several degrees.
Testing of the
"old" modules indicated that they were not susceptible to these operating characteristics.
It was determined that both of these modules are iden-tified with the same 'part number and technical specifications.
The original Riley modules were identified at Susquehanna as Riley model No.
163C1940P001, 2, 3, 4.
The new Riley modules are identified as model No.
164C5687P103, 10 The AC distribution system at Susquehanna consists of two 230KV/13.8KV Startup Transformers (T-10 and.T-20) which are common to both units and provide offsite power to 'the Class 1E power system.
Each Startup Transformer in turn feeds a 13.8KV Startup Bus.
Each bus supplies two Unit 1, 4. 16KV buses and two Unit 2, 4. 16KV buses.
Transformer T-10 supplies Division I buses in each unit and transformer T-20 supplies Division II ESS buses in each unit.
With this type of electrical distribution arrangement, the starting of large induction motors fed from the Unit 1 Division ESS buses results in the Unit 2 Division I loads.
being slightly affected by voltage transients.
This configuration r esulte'd in lowering the panel voltage at the Unit 2 Riley modules since the Unit 2 Division I isolation instrumentation is supplied from the same power source that feeds the Unit 1 Division I large motor loads.
This situation is also present when star ting large induction motors fed from a Unit 1 Division II ESS bus since it can result in a Unit 2 Division II RWCU isolation.
Review of the causes of the RWCU isolations indicated that several factors must be present to cause the Riley temperature modules to trip.
Specifically,'alse steam leak detection isolations can occur when (1)
Riley modules contain the new voltage sensitive cards; (2) voltage dips occur due to large induction motor starts; and (3) high outside ambient temperatures are present.
The high outside ambient temperatures contribute by increasing the room temperature closer to the temperature trip setpoint.
Therefore, once the ambient RWCU room temperature is relatively close to the setpoint, the Riley module will trip upon a
voltage dip since 'this spike will lower the temperature setpoint below the ambient room temperature.
Preliminary bench test results indicate that with an ambient room temperature of 1-2 degrees F from the setpoint, a module,trip can occur with a voltage dip of 4-S VAC.
Other applications of the Riley modules are such that the ambient temperatures are not close to the trip setpoint while others have temperature setpoints much higher than those for the RWCU system.
At this time there is no indication that the RWCU leak detection system would not perform its design function of closing the RWCU isolation valves in the event of a RWCU steam leak to prevent the loss of reactor coolant.
At the conclusion of this inspection, the manufacturer had not yet formally responded to the licensee's concerns regarding the application of the new Riley modules.
The licensee has replaced the modules installed in the RWCU steam leak detection system.
Further actions are being contemplated including the replacement of all the newly installed Riley modules during the next refueling outage.
However, until the-manufacturer provides additional information and recommendations, the licensee does not plan to replace the remaining Unit 2 module Pending review of the manufacturer's recommendations and the subsequent licensee corrective actions to determine the full effect of voltage transients on all the Riley modules, this issue will be considered an Unresolved Item 50-387/88-18-01 and 50'-388/88-21-01.
4.0 Unit 2 125 Volt D-C Desi n Chan e/Modification Non-Conformance Module 37828 During the Unit 2 refueling outage (March 5 - June 24, 1988),
the -licensee performed design change modifications under DCP85-3101B to the Unit 2 Reactor Recirculation Pump (RCP) Trip ATWS circuits to reflect the Unit
design.
In Unit 1, RCP trip channels A and C are powered from Division I 125,volt D-C and channels B and D are powered from Division II.
Unit 2 RCP trip channels A and B were powered from Division I and C and D were powered from Division IJ.
In making the modification, new power wiring was pulled from Division I to Channel C and from Division II to Channel B
However, the modification was completed without remov-ing the existing power feeders to these channels.
This in effect jumpered the Division I and Division II 125 volt D-C power supplies together which paralleled them through the power feeders.
The extra -jumpered or parallel wiring condition was discovered by the licensee during an investigation for grounds on the 125 volt D-C systems and was reported to the NRC in Non-Conformance Report 88-0631, dated Sep'tember 20, 1988.
A review was made of the licensee's NCR including the findings, corrective actions, and Safety Evaluation Assessment (SEA) EE-130, dated September 28, 1988.
The licensee's findings and corrective actions include the jumpers and their removal in Unit 2 and the confirmation that this condition does not exist in Unit 1.-
Licensee document SEA EE-130 provides analyses to assess the ability of the plant systems to fulfilltheir safety functions with the jumpered power supplies during ( 1)
a design bases accident with loss of offsite power and single failure; (2) the occurrence of an ATWS event; and (3) During an Appendix R event.
Analyses were also made to determine the effect on the power supplies themselves of having the two 125 volt D-C divisions paralleled through the jumpers when battery chargers are in either the float or equalizing condition.
The conclusions of the licensee analyses were that the 125 volt D-C systems would have been able to perform their safety related functions for the scenarios assessed in the study.
However, the installed condition of the jumpers represented a degradation of the required separation and isolation of redundant class 1E power supplies (10 CFR 50, Appendix A Criterion 17)..
The jumpers also increased the level of challenge to the redundant class 1E systems from a single failure.
The separation of the two jumpered systems by the circuit-breakers overcurrent trip devices alone between the two redundant systems does not provide the required isolatio A review was made of the licensees design and modification procedures in order to assess their adequacy in the control and implementation of plant modifications.
The following procedures were reviewed.
ops-9 Control of Modifications and Design Activities NDI-QA-15.2. 11 Plant Modification Classification and Control NDI-QA-15.2. 6 Interim Configuration Control Program NOI-QA-15.2.7
'rawing Change Control No procedural"deficiencies are identified.
The following observations were made of the modification and the modification package.
The top level design modification documents, the work description, the wiring schematic diagrams, and the relay connection diagrams all reflected the removal of the old power supplies wiring and the installation of new wiring.
The lower level field working drawings by which the modification wa,s performed showed the installation of the new wiring but did not show nor require the removal of the old wiring.
Therefore, the field, work could be completed, inspected, and accepted as being correct and -complete based upon the field documents included in the modification construction package.
Neither the licensee's de-energized nor energized circuit tests detected the left-in old wiring.
The point to point cold circuit checks provided electrical continuity and the hot circuit checks verified that the'ircuit devices operated properly with the crosstied wiring.
The design error made by omission of the requirement to remove the
"old wiring" appears to have been an oversight by the design engineer in the preparation of the field working drawings.
The design error was not discovered during review and approval of the field working drawing either at the design level or at the DCP package review level prior to performing the work.
This reflected a
deficiency in the design review process since the higher tier documents reflected both the installation and removal of power wiring.
The installation, check-out test, and turnover procedures appear to have been lacking in the fact they made no provisions to confirm that
the objective of the modification had been accompl,ished i.e., to separate two instrument channels from their class'E power supplies'nd to power them from other class lE supplies.
The crosstied class lE power supplies could have remained crosstied indefinitely had it not been for a ground detection indication -that appeared on both power supply divisions when the problem was on only one of the divisions.
Tracing out this problem uncovered the crosstied wiring.
This deficiency in the licensee's design modification control appears to be an isolated event.
No other similar deficiencies were identified.
This is a licensee identified violation for which no citation will be issued.
,The bases for no citation is described in 10 CFR.2, Appendix C.V.A.
(388/88-21-02).
5.0 Emer enc Diesel Generators Module 51055 A review was made of the procedures and records of surveillance samplings, tests, and analysis conducted for the emergency diesel generator (EDG)
fuel, lube oil, and jacket water for compliance with both technical specification and administrative requirements.
EDG Lube Oil Procedure CH-024-003, EM Diesel Lube Oil, Revision 1 was reviewed.
It requires sampling the lube oil from each EDG crankcase on a monthly basis and conducting analysis for acidity, viscosity, water and sediment, pentane insolubles, and engine wear metal's (copper, iron,,tin, lead and chromium).
Administrative limits are established in the procedure for each of these lube oil containments.
Sampling and analysis test data were reviewed for the samples taken on August 8, 1988.
No deficiencies were identified.
EDG Jacket Water Licensee procedure CH-024-004, Diesel Cooling Water, Revision 3 was reviewed.
It requires sampling the jacket water from each EDG on a
monthly basis and conducting analysis for pH, chloride and the metals (iron, copper and molybdenum).
Analysis for dissolved oxygen and for micro-biological activity are required during each shutdown.
Administrative limits are established in the procedure for each jacket water parameter.
Sampling and analysis test data were reviewed for the samples taken for the months of July, August, and September 1988.
No deficiencies were identifie EDG Fuel Oil Licensee procedure CH-024-002, EM Fuel Oil, Revision 2, was reviewed.
It requires surveillance sampling the EDG fuel oil from the fuel oil storage tanks on a quarterly basis and from each tank truck upon delivery.
Analyses are required by the procedure for viscosity, water and sediment, insolubles, and microbiological activity.
Technical specification requirements/limits for each of these parameters are provided.
Sampling and analysis test data for the month of September were reviewed for compliance with the technical specification limits.
No discrepancies were observed.
The inspector reviewed the licensee's requirements which are imposed upon the fuel supplier to ensure that the fuel is proper for the EDG units.
The licensee fuel purchase order requires the following:
"Specifications:
No.
2 Diesel Fuel Oil for delivery to Susquehanna Steam Electric Station must meet ASTM Specifications D-975 and D-2274."
ASTM specification D-975, Standard Specification for Diesel Fuel Oils, prescribes the required properties of No.
2 diesel fuel at the time and place of delivery. It specifies that the requirements of the specification shall be determined for fuel parameters including flashpoint, cloudpoint, water and sediment, carbon residue, ash, distillation,,viscosity, sulfur, corrosion and cetane number.
ASTM specification D-2274, Standard Test Method for Oxidation Stability of Distillates Fuel Oil, covers the method for measurement of the stability of distillate-fuels under accelerated oxidizing conditions.
Discussions with licensee personnel and a review of licensee diesel fuel procurements indicates, that the licensee is not requiring, and the fuel supplier is not providing, evidence ( such as certified test reports) that the diesel fuel meets the requirements of the ASTM specifications required by the licensee purchase order.
Further, discussions with licensee personnel and a review of licensee diesel fuel analysis did not provide any evidence that the licensee conducts the tests required to verify that the diesel fuel either as stored or as received meets the requirements of the ASTM specifications except for those tests included in licensee test procedure CH-024-003 (viscosity, water and sediment and insoluables).
Failure of the licensee to establish procedures which provide objective evidence that the purchased emergency diesel generator fuel conforms to the ASTM specifications specified by the procurement documents is a violation of= the Code of Federal Regulations Section
CFR 50, Appendix B, Criterion VII Control of Purchased Material (50-387/88-18-03 and 50-388/88-21-03).
6.0 Unresolved Items Unresolved items 'are matters about which additional information is necessary in order to determi'ne whether it is acceptable or a violation.
An unresolved item is discussed in paragraph 3.0.
7.0
~Ei N
The findings of the inspection were discussed with the licensee's representatives periodically during the inspection.,
An exit meeting was conducted on September 30, 1988 at which time the findings of the inspection were presented.
At no time during this inspection was written material concerning the inspection findings provided to the licensee by the inspectors.
The licensee did not indicate that any proprietary information was involved within the scope of this inspection.