ML20210S014
| ML20210S014 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 08/29/1997 |
| From: | Grobe J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Wadley M NORTHERN STATES POWER CO. |
| References | |
| 50-282-97-08, 50-282-97-8, 50-306-97-08, 50-306-97-8, NUDOCS 9709040341 | |
| Download: ML20210S014 (2) | |
See also: IR 05000282/1997008
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August 29, 1997
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Mr. M. D. Wadley
Vice President, Nuclear Generation j
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Northern States Power Company
414 Nicollet Mall
Minneapolis, MN 55401
SUBJECT: NOTICE OF VIOLATION (NRC INSPECTION REPORT 50 282/97008(DRS);
50-306/97008(DRS))
Dear Mr. Wadley:
This will acknowledge receipt of your August 15,1997 letter in .9sponse to our
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July.16,1997 letter transmitting a Notice of Violation associated with the above
mentioned inspection report. This report summarized the results of the system operational
performance inspection at your Prairie Island Plant. We have reviewed your corrective
actions and have no further questions at this time. These ccrrective actions may be
examined during future inspections.
Sincerely,
/s/ J. A. Grobe
John A. Grobe, Acting Director
Division of Reactor Safety
{
Docket No.- 50-282 .I
Docket No. 50-306
Enclosure: Ltr 08/15/97, J.' P. Sorenson,
- NSP, to US NRC w/enci
See Attached Distribution
DOCUMENT NAME: G:\DRS\PRA082_7.RS2
To receive a copy of this document, Indicate in the box 'C" = Copy w/o attach /encI T = Copy w/ attach /enct "N" = No copy
OFFICE Rlil:DRS c, Rill:DRS - l C. Rill:DRP lg Rlll:DRSf.y, M
NAME Guzman/kjc K Ring ')ftf(, McCormick-BargJacobs g e
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DATE 08/'b)/97 l 08/24 /97 08/pg)/97 v'" 08/ 3/97
9709040341 970829 e "' AL RECOR D COPY '
PDR ADOCK 05000282
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M. D. Wadley-
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cc w/o encl: Plant Manager, Prairie Island
cc w/ encl: State Lialson Officer, State l
of Minnesota
State Liaison Officer, State
of Wisconsin
Tribal Council, Prairie Island
Dakota Community
Distribution:
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Docket File w/enct Rlli PRR w/ encl Rlli Enf, Coordinator w/enci
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6541 w/enci SRI,- Prairie Island w/enci - TSS w/enci
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/LFDCB'W/shcl LPM, NRR w/enci
- DRP w/enci - A. B Beach, Rill w/enci
- DRS w/enci J. L. Caldwell, Rlli w/enci-
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N::rthern States Power Company
Prairie Island Nuclear Generating Plant
1717 Wakonado Dr. East
Welch. Minnesota 55089
August 15,1997 10 CFR Part 2 )
U S Nuclear Regulatory Commission
Attn: Document Control Desk
Washington, DC 20555
PRAIRIE ISLAND NUCLEAR GENERATING PLANT
Docket Nos. 50-282 License Nos. DPR-42
50-306 DPR-60
Reply to Notice of Violation (Inspection Report 97008),
Deficiencies in the Corrective Action and Calculation Verification Programs
Your letter of July 16,1997, which transmitted Inspection Report No. 97008, required a
response to a Notice of Violation. Our response to the notice is contained in the
attachment to this letter.
In this letter and attached response we have made new Nuclear Regulatory
Commission commitments, these are indicated by italics.
Please contact Jack Leveille (612-388-1121, Ext. 4662) if you have any questions
related to t is letter.
(i L
Joe (of
l P Sorensen
Plant Manager
Prairie Island Nuclear Generating Plant
c: Regional Administrator- Region lil, NRC
Senior Resident inspector, NRC
NRR Project Manager, NRC
J E Silberg
Attachment: RESPONSE TO NOTICE OF VIOLATION
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RESPONSE TO NOTICE OF VIOLATION
VIOLATION 1
10 CFR Part 50, Appendix B, Criterion XVI, " Corrective Action," requires, in part, that
conditions adverse to quality are promptly identified and corrected; and in the case of
significant conditions adverse to quality, the cause of the condition shall be
documented, appropriately reported to levels of management, and corrective action
teken to preclude repetition.
Contrary to the above, as of May 16,1997, a significant condition adverse to quality,
which was identified 4 years earlier, had not been fully corrected. The significant
condition adverse to quality was that cable tray inttallations did not meet the separation
criteria specified in USAR Section 8.7.2. The condition was identified in February 1992
and it took over 4 years, until July 1996, to conclude that the cable tray configurations
were outside the plant's design basis. After this determination, the licensee did not
identify that the scope of the problem went beyond the original trays until the NRC
identified more cable trays, including the pressurizer heater circuits, that did not meet
the separation criteria.
This is a Severity Level IV violation (Supplement 1).
Resoonse to violation 1
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Reason for the Violation
Backaround:
Prairie Island's configuration management (CM) program description was submitted to
the NRC in November 1989 (letter from CE Larson to A Bert Davis). CM's efforts over
the past few years has resulted in 34 Design Basis Documents being developed and
verified. This effort resulted in 910 Follow-On items (FOls) with 1311 recommended
action items. All 910 FOls were assessed (100%) which included operability and
reportability determinations,842 FOls are closed (93%) ,1176 actions are completed
(90%). Efforts to close the remaining action items are in progress.
FOl A0688 " Cable Tray Separation" was initiated in August,1992 and assessed in
February,1993. The assessment determined that the cable tray system condition was
operable and not reportable. The actione recommended by the assessment included
installing cable tray barriers where adec,uate separation was not demonstrated and
providing an evaluation of the acceptability of the present configuration..
The subsequent course of action was to prepare a sdety evaluation to analyze and
justify the as-found condition that would strengthen the hitial operability determination
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Att*chment
August 15,1997
Page 2
in the FOI assessment. This phase of the project focused on evaluating the 38 cases
documented in the FOI assessment.' The goal was to complete the safety evaluation
and present it to th9 plant Operations Committee for concurrence on system operability
along with a recommendation to install barriers to restore separation. During t:.as phase
of work, the assigned engineers concluded Pl should not pursue justification of the as-
found condition on a permanent basis by a change to the separation criteria.
The safety evaluation evolved from the originaljustification based on IEEE 384-1977
requirements to a more formal application of IEEE-384-1992 and also the application of
reduced cable tray separation requirements based on industry testing. During this time,
a representative of the IEEE committee that documented the industry cable tray
separation testing program was contacted for information. The safety evaluation draft
was revised and strengthened numerous times as guidance from IEEE Standard 384,
which postdates the design of Prairie Island, was applied to upgrade the operability
bases of the as-found installation.
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During this time the reportability question was revisited. A written reportability
determination which determined the condition was not reportable was prepared in July
1994 and distributed among the engineering team monitoring the task for concurrence.
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This determination concluded the condition was not in complete compliance with the
USAR separation criteria as written but it was in conformance with USAR statements
that formed the basis of the USAR numerical separation criteria. It therefore was not
. reportable under 10CFR 50.72 (b) (1) (ii) (B), " Condition Outside the Design Basis "
This determination was prepared to establish non-reportability to the safety evaluation
preparers but it was not presented to the Operations Committee.
The completed safety evaluation was presented to the Operations Committee for
concurrence with the enhanced operability determination in July 1996. This evaluation
justified each case of cable tray separation discrepancy by sequentially applying
different methodologies that were developed from guidance in the IEEE standard and
industry testing. The safety evaluation was accompanied by two reportability reviews
prepared per plant procedures and guidance. For " Conditions Outside the Design
Basis," the guidance document notes there are varying industry interpretations.
Lacking specific direction for this issue, two reportability reviews ( one of a non-
reportable condition and a second for a reportable condition) were prepared for OC
review In that meeting the Operations Committee did determine the issue was
reportable under 10CFR 50.72 (b) (1) (ii) (B), " Condition Outside the Design Basis."
After the report was submitted, conference' calls with NRC NRR and Region 111 ensued
and the safety evaluation was discussed. Up to this point the scope of the problem
beyond the initial 38 cases was not considered as the focus of this task was on the
operability of what had been found to date. While NSP engineering was evaluating the
next course of action and planning the LER response, the NRC resident inspector
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emphasized his concern for the issue by initiating their own inspection and finding
three additional cases that appeared to violate the separation criteria explained in the
safety evaluation. These cases were evaluated as operable but one of these was also
reported under the same regulation.
The 30 day written LER report subsequently submitted by NSP committed to do the l
following: l
1. " Plant cable tray separation design and installation, including both original
plant design and subsequent modifications, will be reviewed and all
separation discrepancies identified will be evaluated and resolved. This
work will be executed as follows:
A. Plant cable tray installation drawings will be color coded by
separation groups (trains and channels) and reviewed to identify
possible cable tray separation discrepancies. A discrepancy
occurs when two or more trays in a given P'ea are closer together
than allowed by the cable tray separation enteria and tray barricrs
are not installed in accordance with the plant design drawings.
Cable tray separation criteria are defined in the USAR and plant
- design documents. This evaluation will be performed in plant areas
j that include safety related cable trays with the exception of the
newly constructed (1992) D5/D6 Building (which is designed to
current standards and includes separation groups separated by
building areas).
B. All potential cable tray separation discrepancies will be physically
inspected and the separation will be documented, in addition, all
cable tray barriers shown on the drawings will be inspected. Each
cable tray separation discrepancy confirmed by the physical
inspection will be identified, evaluated, and resolved. The
evaluation, in addition to tray separation issues noted above, will
include a review to confirm Appendix R safe shutdown is not
affected by the cable tray interaction. The evaluation will include a
determination of operability, and if required, appropriate entry into
Technical Specification LCO conditions, and possible
compensatory actions. The inspection will also evaluate the
accuracy of installation drawings for tray separation distances
versus the as-built installation.
2. A safety evaluation will be written to evaluate all cases of cable tray
separation discrepancies that are identified as valid by this project.
IR97008. DOC
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3 The Site Engineering Manual will be revised to more clearly define the
requirements for installation and maintenance of barriers when required
for cable tray separation.
4. Implementation Schedulo.
All cable tray separation discrepancies identified to date will be resolved
by restoring cable tray separation to USAR and plant design
requirements. The deadlines for this restoration is as follows:
. Unit 2: By the end of the next refueling outage which is scheduled
to commence in January,1997.
. Unit 1: By April 1,1997.
For the cable tray separation design and installation review discussed in
Item 1 above, Corrective Action 1.A has already been started. We will
provide future status reports to the Resident inspector on Actions 1
through 3.
5. An independent review of existing reportability determinations on open
Follow-on item (FOI) assessments (from the Design Basis Documentation
and Validation program) will be conducted. Initially a sample of 10% (10
FOls) of the open FOls (93) will be reviewed. This review will be
completed by October 31,1996. If warranted by the findings, the sample
will be increasef 'o that there is reasonable assurance that all FOls
currently oper he e been evaluated accurately for operability and
reportability.
6. Consider training plant electrical system and design engineers and quality
control inspectors on the following:
. Licensing and design requirements for cable tray separation.
. Installation requirements for trays and required barriers to comply
with the design requirements and drawings.
- Requirement to maintain cable tray separation and barrier
installations during subsequent plant modification and work
activities."
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Reason for Violation
The irdividuals involved in developing and writing the safety evaluation were untimely in
completing the document. These individuals were incorrect in determining the issue !
was not reportable under 10CFR 50.72 (b) (1) (ii) (B), " Condition Outside the Design
Basis". These individuals also failed to concurrently determine the extent of the cable
tray system separation discrepancies beyond the initialidentified cases, develop and
plan the corrective actions, and present these corrective action recommendations along
with the safety evaluation for Operations Committee review.
Corrective Actions Taken and Results Achieved
Actions to review the operability and reportability determinations made in previous FOl
assessments and to determine the extent of the cable tray system separation
discrepancies were committed to in the LER-96-13 respunse summarized above. The
status of these actions will be addressed in the next section.
Corrective Steos That Will Be Taken to Avoid Further Violations:
A. Untimely Corrective Action
in response to untimely corrective action program concems noted in the 1997
, Aux Feedwater System SSOP1, NSP assessed its corrective action program,
which includes FOI action items, and identified the following strengths,
weaknesses, changes completed and changes planned:
Corrective Action Program Strengths:
. Numerous problems self-identified (several generic issues identified)
. Staff empowered to identify problems and initiate corrective actions
. System engineering ownership results in high degree of system operability
and reliability
. Operability and reportability determination documentation improving
Corrective Action Program Weaknessei
. Many separate corrective action vehicles
. Lack of management involvement in prioritization
. Resources
. Status of some corrective action vehicles not reported to upper management
or other affected personnel
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Corrective Action Program Changes Comoleted
e Procedures revised to require additional management involvement in OEA !
prioritization
e Open OEA recommendations reprioritized
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Sample of open FOls reviewed for proper operability and reportability
assessment
Corrective Action Program Near Term Changes:
e New condition reporting system to be introduced by September 1997
(consolidates some corrective action vehicles)
- Corrective action process owner designated by September 1997
- Employee Observation Report System revised by September 1997
e Resource authorizations approved, vacancies being filled.
Corrective Action Program Longer Term Changes:
- Institute a management oversight committee by December 1997
e Improve corrective action status reporting functions by December 1997
l e Perform industry review of effective corrective actions programs by December
1997
e Institute additional corrective action program improvements in 1998
B. Incorrect Reportability Determination and Cable Tray Separation Restoration
The present status of Actions 1 through 6 from LER-96-13 listed above are as
follows:
1. Complete for Unit 2 and common plant areas. Unit 1 will be completed by
end of next scheduled refueling outage presently planned to start in
October 1997
2. It was determined by the Operations Committee that the safety evaluation
format was not appropriate to address operability of existing cable tray
separation discrepancies as they were confirmed from drawing review and
inspections activities. In response an interim operability justification
document was issued, and each confirmed separation discrepancy has
been evaluated for operability against that document.
3. Engineering Manual Section 3.3.2.7 " Engineering Design Standard for
Electrical Separation" was revised in October 1996 (Rev. 2) to incorporate
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the safety evaluation basis and methodology, An additional revision to
incorporate information on the detailed cable tray separation criteria
developed during the project is planned.
4. The separation restoration for the initial 41 cases of separation
discrepancies covering both Units 1 and 2 was completed on schedule.
5. The Independent review of a sample of previous FOI assessments was
completed in October 1996. "No instances of reportability or inoperability i
were inund. However some (three) of the FOls need further work to !
reach final reportability and operability determinations." For the three
referenced FOls requiring additional action items, one is complete, one is
in final review, and one is ongoing.
6. Training request has been submitted and the initial program presentation
is being developed for presentation in 1997 before the Unit i refueling
outage.
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Date When Full Comollance Will Be Achieved !
Restoration of cable tray separation will be achieved by the completion of the next
planed Unit i refueling outage presently scheduled to begin in October 1997. Other l
corrective actions listed in this report that address untimely corrective action, incorrect
reportability determinations, and non-modification cable tray separation actions will be
cornpleted in 1998.
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VIOLATION 2
10 CFR Part 50, Appendix B, Criterion lll " Design Control," requires, in part, that design
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control measures shall provide for verifying or checking the adequacy of the design,
such as by performance of design reviews or by use of alternate or simplified
calculations.
Contrary to the above, as of the issue date for the calculations listed below, the design
control measures failed to verify the adequacy of the design in that mathematical and
process errors were not identified or new errors were introduced during the verification.
. "Lt .ndensate Storage Tank Piping Friction Loss NPSH " M 376 CD 001, Revision 0,
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October 1990, new errors were introduced by the independent reviewer who omitted
approximately 45 feet of piping, ignored head losses through the entrance nozzle
and pipe reducers, and used an incorrect value when determining the head loss
through elbows.
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" Maximum Out of Service Time for Steam Line Drains Upstream of the Auxiliary
Feedwater Pump Steam Supply Control Valves CV 31998 & CV 31999,"
SYS AF-002, Revision 0, January 1992, contained errors in that it ignored 11 feet of l
piping. Also the independent reviewer introduced a mathematical error on the !
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magnitudo of 10 by falling to properly convert from seconds squared to hours j
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. " Determination of Possible Flow Rate in Cooling Water (CL) to Auxillary Feedwater
Pump Piping with Gate Valve Half Open to Verify Design Flow Will Pass Thru Half
Open Gate Valve." ENG-ME 792, Revision 0, October 1992, contained errors in that
it contained the wrong number of elbows, used the wrong pipe size; and was based
on a non conservative pressure.
. " Detailed Analysis of Auxillary Feedwater Pump Room Internal Flooding,"
V.SMN.94.006, Revision 0, April 1994, contained errors that doubled the flowrate of
water under a room door and overestimated the capacity of a covered trench by at
least ten percent..
. " Cooling Water Header Pipe Failure Causing Flooding in the Auxillary Feedwater
Pump / instrument Air Compressor Room," Revision 1, ENG ME 148, August 1995,
. contained errors in that it used the results of V.SMN 94.006 without question and
assumed that V.SMN.94.006 calculated the capacity of the floor drains to remove
. water, when V.SMN,94.006 did not address the drains.
This is a Severity Level IV violation (Supplement 1).
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Resoonse to Violation 2
Weaknesses were identified during the SSOPl in the area of design control as
evidenced by discrepancles noted in specific calculations. As a result of the findings
during the inspection five calculations required either a revision to correct a discrepancy
or, in one instance, an additional calculation to provide justification for a basis used in a
calculation. In all cases, the errors were determined to be minor and had no effect on
the conclusions of the calculation.
Reason for the Violation
The reason for the violation in the area of Design Control stems from a failure to
rigorously adhere to the requirements in the Prairie Island Site Engineering Manual.
Failure to follow the specified requirements can be attributed to one of the following
reasons:
. Personnel may be unaware of the requirements. Without knowing the extent of
the requirements in the Site Engineering Manual, site engineering personnel
were completing the verification process to a perceived standard. This
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misconception resulted in analytical results that may not have always been
f completely correct; however, in all cases noted, the correct course of action was
selected and the conclusions were consistently conservative.
. Management failed to explicitly communicate expectations regarding the use of
these requirements. Training has been previously performed on the Site
Engineering Manual. However, training specifically focused on the requirements
and expectations regarding the necessary rigor applied to the preparution and
verification calculations has not been previously performed. Failure to complete
this training has resulted in a failure to appropriately communicate these
expectations.
Corrective Actions
NSP is taking the following short and long term actions to address the specific and
programmatic weaknesses,
Short Term
The following short term corrective actions have been completed:
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1. The subject calculations have been revised to correct the discrepancies. As
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previously noted, the revisions have similar conclusions as the original
calculations,.
2. The awareness of the engineering staff has been heightened to the importance
of taking a rigorous approach to the preparation, checking and verification of all
calculations. This is addressed further as part of the longer term corrective
actions.
Long Term
The following long term corrective actions will be taken to address programmatic
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lasues:
1. The administrative controls for the preparation, checking and verification of
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calculations are specifically covered in the Site Engineering Manual. A review of
these controls indicates that the current requirements are adequate. The
weakness is in the implernentation of the requirements; that is, the engineering
staff have not been adequately trained in regards to these requirements and the
expectations for their use. To alleviate this problem, training will be conducted
by October 18,1997 to ensuse allpersonnel responsible for the preparation,
checking and verification of calculations are aware of the requirements and
expectations with regards to the rigorous approach for their use. This rigorous
approach includes ensuring that design inputs and assumptions are correct and
referenced, verification that the methodology is correct, confirming the adequacy
of the calculation techniques, etc.
2. A sample of calculations wik be reviewed to determine the extent of the potential
problem with inaccuracies in design calculations by March 31,1998. The
calculations reviewed durin0 this sample will be selected based on safety
significance. A higher degree of the sample will be focused on pump and
hydraulle mechanical calculations, This is based on the inspection report which
stated that calculations in others disciplines were acceptable. The sample will be
reviewed for suitability of inputs and assumptions, accuracy of calculation
techniques and adequacy of the final conclusions.- The scope of the sample will
be expanded as necessary, depending on the results of the initial sample.
3. A review of the specific calculations used to support information in the Safety
Analysis Report will be reviewed as part of the USAR Update Project. This
review will focus on verifying the assumptions and inputs to these analyses. The
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accuracy and suitability of these inputs will be confirmed, and the calculation
result will be reviewed to ensure that it is reasonable.
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Date When Full Comollance Will Be Achieved
Full compliance has been achieved.
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