[Federal Register Volume 62, Number 150 (Tuesday, August 5, 1997)]
[Notices]
[Pages 42146-42149]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-20546]


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NUCLEAR REGULATORY COMMISSION

[Docket No. 50-309]


Maine Yankee Atomic Power Company; Maine Yankee Atomic Power 
Station; Issuance of Director's Decision Under 10 CFR 2.206

    Notice is hereby given that the Director, Office of Nuclear Reactor 
Regulation, has taken action with regard to a Petition for action under 
10 CFR 2.206 received from Mr. Patrick M. Sears (Petitioner), dated 
August 19, 1996, and revised on April 14, 1997, with regard to the 
Maine Yankee Atomic Power Station.
    The Petitioner requested the NRC to (1) fine Maine Yankee Atomic 
Power Company (MYAPCO) and Yankee Atomic Electric Company (YAEC) if 
records regarding use of the computer code RELAP have not been kept in 
accordance with YAEC's computer code quality assurance procedures and 
(2) inspect all users of RELAP and fine those users not operating 
within required computer code verification procedures.
    The Director of the Office of Nuclear Reactor Regulation has 
acknowledged parts (1) and (2) of the Petition. The reasons for this 
decision are explained in the ``Director's Decision Pursuant to 10 CFR 
2.206'' (DD-97-17), the complete text of which 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 for the Maine Yankee Atomic Power 
Station located at the Wiscasset Public Library, High Street, P. O. Box 
367, Wiscasset, Maine 04578.
    A copy of this Decision will be filed with the Secretary of the 
Commission for the Commission's review in accordance with 10 CFR 
2.206(c). As provided by this regulation, this Decision will constitute 
the final action of the Commission 25 days after the date of issuance 
unless the Commission, on its own motion, institutes review of the 
Decision within that time.

    Dated at Rockville, Maryland, this 30th day of July 1997.

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

Director's Decision Under 10 CFR 2.206

I. Introduction

    On August 19, 1996, Patrick M. Sears (Petitioner) filed a Petition 
with the U.S. Nuclear Regulatory Commission (NRC) pursuant to Section 
2.206 of Title 10 of the Code of Federal Regulations (10 CFR 2.206). 
Petitioner requested the NRC to (1) Fine Maine Yankee Atomic Power 
Company (MYAPCO) and Yankee Atomic Electric Company (YAEC) if records 
regarding use of the computer code RELAP5YA have not been kept in 
accordance with YAEC's computer code quality assurance (QA) procedures, 
and (2) inspect all users of RELAP and fine those users not operating 
within required computer code verification procedures.
    As the basis for these requests, the Petition states that (1) The 
May 5, 1989, oral statement of Steve Nichols, then licensing supervisor 
of MYAPCO, to Petitioner, then NRC Project Manager for Maine Yankee 
Atomic Power Station (MYAPS), that RELAP5YA was ``operable'' and would 
be used for subsequent reloads was false; (2) no computer code 
inspections were performed by NRC before a 1992 inspection at YAEC by 
Mr. Sears, and not again until 1995; (3) when Mr. Sears was in the 
Vendor Inspection Branch, he was told not to do any more computer code 
inspections; (4) RELAP is widely used; (5) RELAP has been shown to have 
serious deficiencies; and (6) the RELAP problem is not confined to the 
MYAPS but is endemic to the industry as a whole.
    On September 24, 1996, Mr. William T. Russell, then Director of the 
Office of

[[Page 42147]]

Nuclear Reactor Regulation, acknowledged receipt of the Petition. By 
letter dated April 14, 1997, Petitioner supplemented his Petition by 
correcting his characterization of Mr. Nichols' comment, substituting 
the word ``operational'' for ``operable''.

II. Background

    As a result of concerns regarding small-break loss-of-coolant 
accident (SBLOCA) analyses of emergency core cooling systems (ECCS) 
raised by the 1979 accident at Three Mile Island Unit 2, and pursuant 
to 10 CFR 50.54(f), the NRC required licensees to submit revised, 
documented SBLOCA analyses which were to meet the guidance provided in 
NRC's ``Clarification of TMI Action Plan Requirements'' (NUREG-0737 or 
TMI Action Plan), Item II.K.3.30. and II.K.3.31. In response to the 
guidance of Item II.K.3.30, on January 14, 1983, Maine Yankee submitted 
a report, YAEC-1300P, ``RELAP5YA: A Computer Program for Light Water 
Reactor System Thermal-Hydraulic Analysis'' to the NRC. In January 
1989, the NRC approved RELAP5YA for use by Maine Yankee as a 10 CFR 
Part 50, Appendix K, evaluation model, acceptable to demonstrate 
compliance with the requirements of 10 CFR 50.46, ``Acceptance criteria 
for emergency core cooling systems for light water nuclear power 
reactors.'' RELAP5YA is a generic, non-plant-specific LOCA computer 
code for calculating ECCS performance over the small-break portion of 
the break spectrum.
    Item II.K.3.31 of the TMI Action Plan states that licensees are to 
submit plant-specific calculations using the SBLOCA evaluation model 
approved by the NRC pursuant to Item II.K.3.30. In response to TMI 
Action Plan Item II.K.3.31, YAEC prepared for Maine Yankee a plant-
specific Appendix K, RELAP5YA SBLOCA evaluation model analysis and 
prepared a report in June 1993 identified as YAEC-1868: ``Maine Yankee 
Small Break LOCA Analysis.'' The SBLOCA analysis described in YAEC-1868 
was used to prepare Core Performance Analysis Reports (CPARs) which 
were submitted to the NRC as part of Maine Yankee's reload analyses for 
Cycle 14 and Cycle 15 operations, and was the SBLOCA analysis of record 
throughout Cycle 14 operations; it was not used during Cycle 15 
operations because of the intervening January 3, 1996, ``Confirmatory 
Order Suspending Authority for and Limiting Power Operation and 
Containment Pressure (Effective Immediately), and Demand for 
Information'' (Order).1 61 FR 735 (January 10, 1996).
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    \1\  Among other things, the Order limited operation of MYAPS to 
2440 MWt, pending NRC review and approval of a plant-specific SBLOCA 
analysis which conforms to TMI Action Plan Items II.K.3.30 and 
II.K.3.31 and which meets the requirements of 10 CFR 50.46.
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    On December 4, 1995, the NRC received allegations that, among other 
things, YAEC, acting as agent for the licensee, knowingly performed 
inadequate analyses of the emergency core cooling system (ECCS) to 
support two license amendment applications to increase the rated 
thermal power at which MYAPS operates to 2630 MWt, and then to 2700 
MWt. It was further alleged that YAEC management knew that the ECCS for 
Maine Yankee, if evaluated in accordance with 10 CFR 50.46, using the 
RELAP5YA SBLOCA evaluation model, did not meet licensing requirements.
    In response to the allegations, NRC dispatched an Assessment Team 
to YAEC headquarters between December 11 and 14, 1995, to examine, 
among other things, SBLOCA analyses, especially the SBLOCA analysis 
which supported the licensee's operating Cycle 15 reload application. 
Based on the Assessment Team review, and a meeting held with the 
licensee on December 18, 1995, the NRC staff issued its January 3, 
1996, Order. The Order concluded, inter alia, that the licensee had not 
demonstrated that computer code RELAP5YA would reliably calculate the 
peak cladding temperature for all break sizes in the small-break LOCA 
spectrum for Maine Yankee and that, for a variety of reasons, the 
plant-specific application of RELAP5YA did not conform to the 
requirements of 10 CFR 50.46 and thus was not acceptable for use by the 
licensee. The Order required the licensee to submit a SBLOCA analysis 
specific to Maine Yankee for operation at power levels up to 2700 MWt, 
which must meet the requirements of 10 CFR 50.46, and which must 
conform to the guidance of NUREG-0737, Items II.K.3.30 and 31, ``SBLOCA 
Methods'' and ``Plant-specific Analysis,'' respectively, and NUREG-
0737, Item II.K.3.5, ``Automatic Trip of Reactor Coolant Pumps During 
LOCA''. The Order suspended authority to operate Maine Yankee at 2700 
MWt maximum power and limited power to 2440 MWt, pending NRC review and 
approval of the required SBLOCA analysis. MYAPCO submitted the required 
SBLOCA analysis specific to Maine Yankee on April 25, 1996, and the NRC 
staff is currently reviewing it.
    The NRC also initiated an investigation by the NRC Office of 
Investigations (OI) to examine possible wrongdoing. The NRC staff is 
currently reviewing the results of that investigation.

III. DISCUSSION

A. Do MYAPCo and Other NRC Licensees Who Use RELAP Operate Within 
Required Computer Code Verification Procedures?
    Petitioner requests that the NRC inspect all users of RELAP and 
fine those users not operating within required computer code 
verification procedures. The staff presumes that the phrase ``required 
computer code verification procedures,'' as used by Petitioner, means 
the conditions, if any, of the NRC's approval of the computer code, as 
well as the licensee or vendor quality assurance (QA) procedures 
pursuant to 10 CFR part 50, Appendix B.
    There are many vintages of RELAP, which was developed by Idaho 
National Engineering Laboratory, such as RELAP4, RELAP5/MOD1, RELAP5/
MOD2, and RELAP5/MOD3 (higher suffix numbers indicate more current 
vintages). Major improvements were made in each new vintage, including 
the use of more sophisticated modeling of two-phase flow. For example, 
RELAP5/MOD1 has a ``mixture'' model with five governing equations, 
whereas RELAP5/MOD2 has a full two-fluid treatment with six equations.
    Each vintage of RELAP has many versions, representing primarily 
modifications in supporting models on constitutive relationships and 
corrections of errors. Idaho National Engineering Laboratory maintains 
a reporting system for problems discovered by users of the code, which 
are prioritized and referred to the code development staff for 
resolution. Therefore, it cannot be assumed that a problem with a 
particular RELAP vintage or version also exists in other RELAP vintages 
or versions.
    Vendors or licensees who use RELAP codes to support license 
applications normally take a specific vintage or version of RELAP and 
create their own variations by making modifications and adding certain 
features, such as those required by 10 CFR part 50, Appendix K. The 
RELAP codes used by different vendors and licensees are not necessarily 
developed from the same versions or vintages of RELAP. For example, the 
RELAP5YA code used by YAEC for Maine Yankee SBLOCA analysis was derived 
from RELAP5/MOD1, while most other RELAP codes used for the ECCS 
analyses of NRC-licensed nuclear plants were derived

[[Page 42148]]

from different vintages, namely, RELAP4 or RELAP5/MOD2.
    Before a vendor-modified or licensee-modified RELAP code is used 
for licensing applications, it must be reviewed and approved by the 
staff. The staff's review and approval will require, among other 
things, benchmark comparison of the code's predictions against 
experimental test data. In many cases, the staff's approval of a 
licensing RELAP code imposes conditions or restrictions for application 
of the code to ensure that licensing calculations are acceptably 
conservative, in accordance with the requirements of 10 CFR 50.46 and 
Appendix K to 10 CFR part 50. The implementation by a licensee or 
vendor of an approved emergency core cooling system (ECCS) code is 
controlled by the licensee or vendor's own quality assurance programs 
in accordance with Appendix B to 10 CFR part 50.
    In view of the above, it cannot be presumed that all other vintages 
of RELAP codes used by the industry have the same deficiencies as those 
experienced by Maine Yankee with its particular vintage of RELAP, that 
is RELAP5/MOD1. Two NRC licensees other than Maine Yankee, however, 
used the RELAP5/MOD1 vintage, that is, Yankee Rowe Nuclear Power 
Station and Vermont Yankee Nuclear Power Station. Yankee Rowe Nuclear 
Power Station has been permanently shut down for decommissioning since 
October 1, 1991. In May 1996, the NRC staff conducted an ECCS code and 
analysis inspection, and in June 1996, a special inspection of Vermont 
Yankee. As a result, the NRC issued a Notice of Violation and Proposed 
Imposition of Civil Penalty--$50,000 (EA 96-210) on August 23, 1996, 
for the licensee's failure to assume a specific failure scenario in the 
LOCA analysis. In that enforcement action, the NRC staff also concluded 
that Vermont Yankee's corrective actions were prompt and comprehensive. 
With respect to Maine Yankee, the NRC staff has examined MYAPCO's use 
of RELAP5YA through the Assessment Team review and the OI 
investigation. The staff's evaluation of Maine Yankee's use of RELAP5YA 
is ongoing with regard to any violations of NRC requirements, including 
10 CFR 50.46. The staff will keep Petitioner informed by providing 
Petitioner with copies of publicly available inspection reports and 
enforcement actions.
    Petitioner, nonetheless, correctly points out that the NRC staff 
should conduct ECCS code and analysis inspections more frequently. In 
February 1997, the staff's Maine Yankee Lessons Learned Task Group 
provided its report to the Commission, ``Report of the Maine Yankee 
Lessons Learned Task Group'' (December 5, 1996), Attachment 1 to SECY-
97-042, ``Response to OIG Event Inquiry Regarding Maine Yankee'' 
(February 18, 1997). The Task Group identified a need to place 
additional emphasis on (1) audits and inspections of implementation by 
licensees and vendors of their ECCS codes and methodologies, not 
limited to the various RELAP codes, and (2) verification of the 
conformance by licensees and vendors with the conditions specified in 
the NRC staff's Safety Evaluation Reports as a basis for determining 
whether codes and methodologies conform with NRC requirements. The Task 
Group also addressed inspections pursuant to the Core Performance 
Action Plan, performed to assess the impact of reload core design 
activities on plant safety. Licensees or vendors found to be in 
violation of NRC regulations will be subject to enforcement actions.
    As explained above, there is no basis to conclude that the problems 
identified with the RELAP5/MOD1 vintage ECCS code used by Maine Yankee 
are or may be present in the different RELAP code vintages at other 
NRC-licensed plants. Additionally, the two other users of the RELAP5/
MOD1 code vintage have either been inspected (Vermont Yankee) or are 
permanently shut down (Yankee Rowe). Nevertheless, the NRC will conduct 
computer code inspections of selected NRC licensees and vendors, not 
limited to users of RELAP, as explained above.
    In view of the above, Petitioner's request to inspect all users of 
RELAP and to fine those users not operating within required computer 
code verification procedures is granted in part, since some users of 
RELAP will be included in forthcoming computer code inspections and 
since Maine Yankee and Vermont Yankee have already been inspected.
B. Have MYAPCO and YAEC Kept Records of the Use of the RELAP ECCS 
Computer Code in Accordance with YAEC's Computer Code Quality Assurance 
Procedures?
    Petitioner requests that the NRC fine MYAPCO and YAEC if records 
regarding use of the computer code RELAP5YA have not been kept in 
accordance with YAEC's computer code quality assurance (QA) procedures. 
The NRC staff's review of the application of RELAP5YA for Maine Yankee 
between December 11 and 14, 1995, focused on the adequacy of the 
RELAP5YA SBLOCA analysis to support operation of Maine Yankee during 
Cycle 15. In particular, the staff evaluated conformance of the code to 
SER conditions and compliance of the ECCS evaluation model with 
regulatory requirements. Although the staff's review did not focus on 
record keeping requirements, the staff did not identify instances in 
which the appropriate records had not been kept. The staff is 
continuing its evaluation of RELAP5YA for compliance with other NRC 
requirements.
    Siemens Power Corporation (SPC) has prepared a plant-specific 
SBLOCA ECCS evaluation model for Maine Yankee, which has been submitted 
by Maine Yankee in response to the January 3, 1996, Order. The 
evaluation model is based on SPC's ANF-RELAP SBLOCA methodology, which 
was originally approved by the NRC in 1989, with further modifications 
approved by the NRC in 1994. Between February 10, 1997 and April 4, 
1997, the staff conducted a four-week QA inspection of SPC. The 
inspection included a comprehensive review of documentation associated 
with SPC's LBLOCA and SBLOCA ECCS evaluation models, including the 
approved ANF-RELAP SBLOCA methodology. The staff's findings associated 
with ANF-RELAP will be documented in the inspection report, which will 
be issued by the NRC in the near future. A copy of the inspection 
report will be provided to Petitioner when it is publicly available. In 
addition, the NRC staff is currently performing a detailed technical 
review of the plant-specific ANF-RELAP ECCS evaluation model prepared 
by SPC for Maine Yankee, and submitted by Maine Yankee. The staff's 
evaluation of the plant-specific evaluation model will be documented in 
a Safety Evaluation Report (SER) when completed. The staff concludes 
that these activities respond directly to the issues raised by 
Petitioner.
    In view of the above, the Petitioner's request for a QA inspection 
of Maine Yankee's and YAEC's use of RELAP is granted in part, by virtue 
of the staff's previous and current inspection and review activities. 
Additionally, the staff will keep Petitioner informed by providing 
Petitioner with publicly available inspection reports, enforcement 
actions, and other documents as appropriate.

IV. Conclusion

    As explained above, Petitioner's request to inspect all users of 
RELAP and fine those users not operating within required computer code 
verification procedures is granted in part. Petitioner's request to 
fine MYAPCO and YAEC if records regarding use of the computer code 
RELAP have not been kept in

[[Page 42149]]

accordance with YAEC's computer code quality assurance procedures is 
also granted in part.
    A copy of this Director's Decision will be filed with the Secretary 
of the Commission for Commission review in accordance with 10 CFR 
2.206(c) of the Commission's regulations. As provided by this 
regulation, this Director's 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 within that time.

    Dated at Rockville, Maryland, this 30th day of July 1997.

    For the Nuclear Regulatory Commission.
Samuel J. Collins,
Director, Office of Nuclear Reactor Regulation.
[FR Doc. 97-20546 Filed 8-4-97; 8:45 am]
BILLING CODE 7590-01-P