[Federal Register Volume 63, Number 55 (Monday, March 23, 1998)]
[Notices]
[Pages 13884-13886]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-7427]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-443]


North Atlantic Energy Service Corporation Seabrook Station, Unit 
No. 1; Issuance of Director's Decision Under 10 CFR 2.206

    Notice is hereby given that the Director, Office of Nuclear Reactor 
Regulation (NRR), has taken action with regard to a Petition dated 
December 18, 1997, submitted by Ms. Jane Doughty on behalf of The 
Seacoast Anti-Pollution League. The Petition requests that the 
operating license for Seabrook Station be suspended until such time as 
a thorough root cause analysis of the reasons underlying the 
development of leaks in piping of the ``B'' train of the

[[Page 13885]]

residual heat removal (RHR) system is conducted. The leakage was 
reported by North Atlantic Energy Services Corporation, the Licensee 
for Seabrook Station, on December 5, 1997. The Petition asserts that 
there have been past allegations of improper welding practices and 
documentation, and installation of substandard piping at Seabrook 
Station and requests that the investigations of the RHR system pipe 
leakage include findings related to these past allegations.
    The Director of NRR has denied the Petitioner's request to suspend 
the operating license of the Seabrook Station. In the Director's 
Decision Pursuant to 10 CFR 2.206 (DD-98-03), the staff of the U.S. 
Nuclear Regulatory Commission has discussed each of the concerns raised 
by the Petitioner and found that the cause of the leaks in the piping 
in the ``B'' train of the RHR system was the result of service-induced 
degradation. There were no deficiencies identified in the fabrication 
of the original piping or welds that would have generic implications 
for other plant systems and that would require the operating license of 
the facility to be suspended. The complete text of the Decision follows 
this notice and is available for public inspection at the Commission's 
Public Document Room, the Gelman Building, 2120 L Street, NW., 
Washington, DC, and at the local public document room located at the 
Exeter Public Library, Founders Park, Exeter, New Hampshire 03833.
    A copy of the Decision will be filed with the Secretary of the 
Commission for the Commission's review in accordance with 10 CFR 
2.206(c) of the Commission's regulations. As provided for by this 
regulation, the Decision will constitute the final action of the 
Commission 25 days after the date of issuance, unless the Commission, 
on its own motion, institutes a review of the decision in that time.

    Dated at Rockville, Maryland, this 17th day of March 1998.

    For the Nuclear Regulatory Commission.
Samuel J. Collins,
Director, Office of Nuclear Reactor Regulation.

Director's Decision Pursuant to 10 CFR 2.206

I. Introduction

    On December 18, 1997, Ms. Jane Doughty submitted a Petition to the 
Executive Director for Operations of the U.S. Nuclear Regulatory 
Commission (NRC) on behalf of The Seacoast Anti-Pollution League 
requesting that the operating license for Seabrook Station be suspended 
until such time as a thorough root cause analysis of the reasons 
underlying the development of leaks in piping of the ``B'' train of the 
residual heat removal (RHR) system is conducted. The leakage was 
reported by North Atlantic Energy Service Corporation, the Licensee for 
Seabrook Station, on December 5, 1997.
    The Petition requested that the restart of the Seabrook Station 
following repairs to the RHR system piping be delayed until all such 
actions requested by the Petition are taken. On January 15, 1998, the 
NRC informed the Petitioner in an acknowledgment letter that on the 
basis of the Licensee's preliminary analysis of the cause of the pipe 
leakage, the NRC staff found no reason to prevent the plant from 
restarting. The acknowledgment letter further informed the Petitioner 
that her Petition had been referred to the Office of Nuclear Reactor 
Regulation pursuant to 10 CFR 2.206 for preparation of a Director's 
Decision and that action would be taken within a reasonable time 
regarding the specific concerns raised in the Petition.

II. Discussion

    The Petition requests, in part, ``that the operating license for 
the Seabrook Station Nuclear Power Plant [Seabrook Station] be 
suspended until such time as a thorough root cause analysis of the 
reasons underlying the development of leaks. . .in piping in the ``B'' 
train of the Residual Heat Removal (RHR) system is conducted, including 
but not limited to a review of documentation associated with welds in 
the area of the leakage and their associated inspection documentation, 
a review of the qualification of the piping involved, and a review of 
the procedures for ongoing assurance of weld and piping quality at the 
plant.'' The Petition asserts that there have been past allegations of 
improper welding practices and documentation, and installation of 
substandard piping at Seabrook Station and requests that the 
investigations of the RHR system pipe leakage include findings related 
to these past allegations and the implications of this incident for 
other plant systems. Each of these concerns is addressed below.

A. Root Cause Analysis

    The Licensee has concluded that the cause of the RHR piping leak 
was chloride-induced transgranular stress-corrosion cracking initiated 
from the outside diameter of the pipe. The stress-corrosion cracking 
was the result of repeated wettings and dryings of a protective 
covering attached to the pipe with red duct tape during construction of 
the facility. The covering was installed to prevent other welding 
activities from damaging the pipe after it was installed and should 
have been removed prior to placing the RHR system in service. After 
being wetted the protective covering and tape leached chlorides, 
allowing the chlorides to concentrate on the outer surface of the pipe 
over time. The chlorides provided an agent to initiate stress-corrosion 
cracking of the stainless steel pipe material. The Licensee has 
conducted an inspection of accessible areas both inside and outside 
containment for similar instances of unapproved materials being 
attached to stainless steel piping and none were found.
    The NRC staff has reviewed the Licensee's conclusions, including 
observations of the failed pipe section and a review of the relevant 
metallurgical and chemistry reports. The NRC staff found that the 
metallurgical and chemistry reports provide an adequate basis for the 
Licensee's conclusion that the leaks were the result of stress-
corrosion cracking initiated from the outside diameter of the pipe that 
progressed through the pipe wall to the inside surface. The NRC staff's 
findings are documented in Inspection Report 50/443/97-08.

B. Review of Weld Documentation

    The Licensee conducted a review of the original radiographs of the 
affected welds and found no anomalies in the weld or the base metal. 
This finding indicates that the cause of the leakage was the result of 
service-induced conditions and not a weld or piping defect originating 
from the original construction.
    The NRC staff's review of the radiographs confirmed that there were 
no adverse construction weld quality problems, such as cracks, 
porosity, or weld slag shown on the pipe weld radiographs in the 
vicinity of the leaks or on the similar welds on the ``A'' train of the 
RHR system. No defective welds were found. The NRC staff's findings are 
documented in Inspection Report 50-443/97-08.

C. Review of Pipe Qualification

    The Licensee reviewed the original material test reports and 
purchase specification documentation for the affected piping sections. 
Chemical analysis of the removed piping sections confirmed that the 
material met the specification for SA312 Type 304 stainless steel pipe.
    The NRC staff's review of the chemistry analysis and 
photomicrographs showed the pipe material to be Type 304 stainless 
steel. The NRC staff's findings are

[[Page 13886]]

documented in Inspection Report 50-443/97-08.

D. Review of the Procedures for Ongoing Assurance of Weld and Pipe 
Quality

    In conjunction with the most recent refueling outage at Seabrook 
Station, the NRC staff conducted a review of the Licensee's American 
Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME 
Code) Section XI inservice inspection program plan for ensuring 
structural and leaktight integrity of systems important to safety. The 
NRC inspector found the implementation of all elements of the program 
to be on schedule and in accordance with the rules of Section XI of the 
ASME Code.
    The NRC inspector observed and/or reviewed the results of inservice 
inspections conducted by the Licensee on plant equipment, including 
several piping welds. The NRC inspector found that the inspections were 
performed in accordance with the rules of Section XI of the ASME Code 
and NRC regulations. The NRC staff's findings are documented in 
Inspection Report 50-443/97-03.

E. Review of Past Allegations of Improper Welding Practices

    On March 27, 1990, the NRC's Executive Director for Operations 
established an independent review team to conduct an assessment of the 
adequacy of the construction welding and nondestructive examination 
(NDE) practices at Seabrook Station. The team's findings are documented 
in NUREG-1425, ``Welding and Nondestructive Examination Issues at 
Seabrook Nuclear Station.'' The independent review team concluded that 
the pipe welding and NDE programs were generally consistent with 
applicable codes and NRC requirements and resulted in technically 
acceptable pipe welds.
    In investigating the leaks in the ``B'' train of the RHR system 
reported on December 5, 1997, the NRC staff did not identify any 
factors that would provide a basis for disagreeing with the Licensee's 
conclusion that the cause of the leakage was the result of service-
induced conditions and not a weld or piping defect originating from the 
original construction. Likewise, the investigation of this issue did 
not provide any information that would question the validity of NUREG-
1425. Therefore, no further action by the NRC staff is warranted with 
respect to the past allegations of improper welding practices and 
substandard quality piping in response to the Petitioner's request.

F. Implications for Other Plant Systems

    The Licensee has concluded that the cause of the leakage in the 
``B'' train of the RHR system reported on December 5, 1997, was the 
result of a service-induced condition and not a defect originating from 
the original construction. The NRC staff has reviewed the Licensee's 
activities related to the root cause analysis and subsequent repair in 
response to the RHR system pipe leakage. The NRC staff found no 
evidence of improper welding practices or substandard piping that 
contributed to the RHR system pipe leakage and that would result in 
generic implications to other plant systems.

III. Conclusion

    The NRC staff has reviewed the information submitted by the 
Petitioner, and the Petitioner's request to suspend the operating 
license of the Seabrook Station is denied. As described above, the NRC 
staff has found that the cause of the leaks in the piping in the ``B'' 
train of the RHR system was the result of service-induced degradation. 
There were no deficiencies identified in the fabrication of the 
original piping or welds that would have generic implications for other 
plant systems and that would require the operating license of the 
facility to be suspended.
    As provided in 10 CFR 2.206(c), a copy of this Decision will be 
filed with the Secretary of the Commission for the Commission's review. 
This Decision will constitute the final action of the Commission 25 
days after issuance, unless the Commission, on its own motion, 
institutes review of the Decision in that time.

    Dated at Rockville, Maryland, this 17th day of March 1998.

    For the Nuclear Regulatory Commission.
Samuel J. Collins,
Director, Office of Nuclear Reactor Regulation.
[FR Doc. 98-7427 Filed 3-20-98; 8:45 am]
BILLING CODE 7590-01-P