ML20137W926
| ML20137W926 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/15/1997 |
| From: | Gallo R NRC (Affiliation Not Assigned) |
| To: | Langenbach J GENERAL PUBLIC UTILITIES CORP. |
| Shared Package | |
| ML20137W930 | List: |
| References | |
| NUDOCS 9704210096 | |
| Download: ML20137W926 (5) | |
See also: IR 05000289/1996201
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UNITED STATES
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NUCLEAR REGULATORY COMMISSION
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WASHINGTON, D.C. 20555-0001
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April 15,1997
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Mr. James W. Langenbach
Vice President and Director - TMI
GPU Nuclear Corporation
Three Mile Island Nuclear Station
Post Office Box 480
Middletown, PA 17057
SUBJECT:
THREE MILE ISLAND - UNIT 1, DESIGN INSPECTION (NRC INSPECTION REPORT
NO. 50-289/96-201)
Dear Mr. Langenbach:
A design inspection at Three Mile Island - Unit 1 (TMI-1) was performed by the
Special Inspection Branch of the Office of Nuclear Reactor Regulation (NRR
including on-s)ite
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during the period November 12, 1996 through January 10, 1997
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inspections during December 2-20, 1996 and January 6-10, 1997. The team
selected for inspection the engineered safeguards functions of the makeup and
purification (MU&P) system and the decay heat removal system (DHRS) because of
the importance of these two sy' stems in mitigating design basis accidents at
TMI-1.
The purpose of the inspection was to evaluate the capability of the
systems to perform safety functions required by their design bases, the
adherence.to the design and licensing bases, and the consistency of the as-
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built configuration with the final safety analysis report (FSAR).
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The results of this inspection are presented in the enclosed report.
The team
noted that the design docurants for the reviewed systems appropriately
implemented the intent of the design and licensing bases except for the
specific cases identified in the report.
Although many calculations reviewed by the team were satisfactory, the team
identified design control weaknesses in the performance and. control of
calculations.
In particular. the team noted the use of several
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nonconservative inputs and as.Jmptions in the analysis for switchover of DHRS
pump suction from the borated water storage tank (BWST) to the reactor
, building sump under post-accident conditions.
The plant was operated outside
the desi_gn basis with potential for air entrainment in the emergency core
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cooling system pumps that could have rendered them inoperable.
You evaluated
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this issue and concluded that the system was inoperable, notified the NRC in
accordance with 10 CFR 50.72 on December 21, 1996, and revised operating
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procedures to resolve the problem.
You also issued a licensee event report
(LER 96-002) on January 20, 1997.
The team identified that calculations were being . performed in documents, such
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as memoranda, technical data reports, and plant engineering evaluation ,
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requests, that do not comply with your engineering procedures for
calculations.
For example, on the basis of a calculation in a memorandum an
incorrect decision was made not to test the check valves in the DHRS pump
suction from the BWST to assure that the check valves are capable of
preventing backflow from the reactor building sump.
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NBC HLE CBilalCOPY
9704210096 970415
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ADOCK 05000289
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Mr. James W. Langenbach
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The' team determined that the consequences of a letdown line break in the
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auxiliary building apparently had not been adequately evaluated.
The team
referred this issue to the technical review branch in the Office of Nuclear
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Reacto,' o gulation (NRR) staff for review regarding the extent to which TMI-l
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was required to consider the effects of a letdown line break in the auxiliary
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building.
The staff review concluded that the THI-1 licensing basis for pipe
breaks includes the postulation of full diameter breaks in the letdown line
between the containment penetration and the b'reakdown orifice as described in
Appendix 14A to the FSAR.
Therefore, the design of safety-related equipment
in the affected areas should consider the conditions resulting from these
breaks.
The team's other findings included: nonconservative assumptions and missing
inputs in calculations for the makeup pumps and makeup tank; a potential
unreviewed safety question in your evaluation of an FSAR change regarding the
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net positive suction head for DHRS pumps; not periodically testing certain
molded case circuit breakers; incorrect alignment of power supply to the
makeup isolation valve; not initiating corrective actions in a timely manner
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for open items from your self-assessments of the two inspected systems; and
tiscrepancies in the FSAR.
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You have implemented appropriate measures to address the immediate concerns
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identified by the team.
For the other issues, you have initiated appropriate
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reviews and corrective actions, such as revision of design documents, changes
to procedures, and further evaluations of the identified issues.
Notwithstanding the weaknesses described above, the team concluded that there
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was evidence that the reviewed systems generally adhered to the design and
licensing bases and the as-built configuration was consistent with the FSAR.
In order for the NRC to coordinate follow-up actions, please provide within 60
days of receipt of this letter a schedule for completion of your corrective
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actions for the open items listed in Appendix A of the enclosed report.
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Any enforcement action resulting from this inspection will be handled by the
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NRC Region I office via separate correspondence.
As with all NRC inspections, we expect that you will evaluate the
applicability of the results of this inspection and the specific findings to
other systems and components.
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Mr. James W. Langenbach
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In accordance with 10 CFR 2.790(a), a copy of this letter and the enclosure
will be placed in the NRC Public Document Room.
Should you have any questions
concerning the attached inspection report, please contact the project manager
Mr. B.C. Buckley at (301) 415-1452 or the inspection team leader Mr. S.K.
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Malur at (301) 415-2963.
Sincerel ,
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6cf.RobertM.Gallo, Chief
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Special Inspection Branch
Division of Inspection and Support Programs
Office of Nuclear Reactor Regulation
Docket No.:
50-289
Enclosure:
NRC Inspection Report No. 50-289/96-201
cc: see next page
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Three Mile Island Nuclear Station, Unit No.1
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cc:-
James W. Langenbach
William Dornsife, Acting Director
Vice President and Director, TMI
Bureau of Radiation Protection
{
GPU Nuclear Corporation
Pennsylvania Department of
]
P.O. Box 480
Environmental Resources
,
Middletown, PA 17057
P.O. Box 2063
Harrisburg, PA 17120
John C. Fornicola
Director, Planning and
Dr. Judith Johnsrud
Regulatory Affairs
National Energy Committee
GPU Nuclear Corporation
100 Interpace Parkway
433 Orlando Avenue
Parsippany, NJ 07054
State College, PA 16803
Jack S. Wetmore
Robert B. Borsum
Manager, TMI Regulatory Affairs
B&W Nuclea'r Technologies
GPU Nuclear Corporation
Suite 525
P.O. Box 480
1700 Rockville Pike
Middletown, PA 17057
Rockville, MD 20852
Ernest L. Blake, Jr., Esquire
Shaw, Pittman, Potts & Trowbridge
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2300 N Street, NW
Washington, DC 20037
Chairman
Board of County Commissioners
of Dauphin county-
Dauphin' County Courthouse
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. Harrisburg, PA 17120
Chairman
Board of Supervisors.
of Londonderry Township
- R.D.-#1, Geyers Church Road
' Middletown, PA 17057
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Michele'G. Evans
Senior Resident Inspector (TIM-1)
U.S. ' Nuclear Regulatory Commission
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P.O. Box 311
Middletown, PA 17057
Regional Administrator, Region I
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U.S. Nuclear Regulatory Commission
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475 Allendale Road
King of Prussia, PA 19406
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Distribution:
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- Docket Files 50-289
PSIB R/F
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ACThandani,-NRR
FPGillespie, NRR
RMGallo, NRR
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DPNorkin, NRR
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CERossi, AE0D
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SAVarga, NRR
JStolz, NRR
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LThonus, NRR
M0'Brien, NRR
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MGEvans,' SRI,
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Regional Administrators
Regional Division Directors
Inspection Team
PUBLIC
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ACRS (3)
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OGC (3)
IS Distribution
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