ML18033A873
| ML18033A873 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 08/14/1989 |
| From: | Medford M TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 8908160352 | |
| Download: ML18033A873 (14) | |
Text
REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ESSION NBR:8908160352 DOC.DATE: 89/08/14 NOTARIZED:
NO DOCKET ii CIL:50-259 Browns Ferry Nuclear Power Station, Unit 1, Tennessee 05000259 50-260 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260 50-296 Browns Ferry Nuclear Power Station, Unit 3, Tennessee 05000296 AUTH.NAME AUTHOR AFFILIATION MEDFORD,M.O.
Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
SUBJECT:
Responds to NRC 890713 ltr re violations noted in Insp Repts 50 259/89 18g50 260/89 18
& 50 296/89 18
'ISTRIBUTION CODE: IE01D'OPIES RECEIVED:LTR ENCL SIZE:
TITLE: General (50 Dkt)-Insp Rept/Notice of Violation Response NOTES:1 R.
1 R.
1 R.
Copy each to: B.Wilson,D.M.Crutchfield,B.D.Liaw,S.Black
- Pierson, Copy each to: S.Black,D.M.Crutchfield,B.D.Liaw, Pierson,B.Wilson Copy each to:
S. Black,D.M.Crutchfield,B.D.Liaw, Pierson,B.Wilson 05000259 05000260 05000296 ~
RECIPIENT ID CODE/NAME PD RNAL'CRS AEOD/DEIIB DEDRO NRR/DEST DIR NRR/DOEA DIR 11 NRR/DREP/RPB 10 NUDOCS-ABSTRACT OGC/HDS2 RES MORISSEAU g D EXTERNAL: LPDR NSIC NOTES'OPIES LTTR ENCL 1
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1 RECIPIENT ID CODE/NAME GEARS,G AEOD AEOD/TPAD NRR SHANKMAN,S NRR/DLPQ/PEB NRR/DREP/EPB 10 NRR/PMAS/ILRB12 N,J
~EL 02 RGN2 FILE 01 NRC PDR COPIES LTTR ENCL 1
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TENNESSEE VALLEYAUTHORITY CHATTANOOGA. TENNESSEE 37401 6N 38A Lookout Place AUB $ 4 1888 U.S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, D.C.
20555 Gentlemen:
In the Hatter of Tennessee Valley Authority Docket Nos.
50-259 50-260 50-296 BROWNS FERRY NUCLEAR PLANT (BFN) UNITS 1, 2, AND 3 NRC INSPECTION REPORT NOS. 50-259/89-18, 50-260/89-18, AND 50-296/89-18
RESPONSE
TO VIOLATIONS This letter provides TVA's response to the letter from B. A. Wilson to O.
D. Kingsley, Jr.
dated July 13,
- 1989, which transmitted the subject reports On January 3,
reactor.
Fuel loading was halted on January 5,
1989 by plant management to evaluate concerns with reload procedures.
Fuel was being loaded in accordance with the technical specifications which allowed less than three counts per second on the source range monitors (SRMs) provided that the SRHs were response checked every eight hours and fuel was loaded in a spiral sequence.
However, with a spiral sequence started at the center of the core, the fuel was neutronically decoupled from the SRHs.
TVA took corrective action to ensure the 74 fuel assemblies that had already been loaded were loaded correctly and to adequately monitor the core.
The fuel loading procedures were revised with assistance from General
- Electric, a
detailed action plan for the resumption of fuel loading was developed, and the NRC staff was briefed on the action plan.
Fuel loading was resumed on January 16,
- 1989, and was completed without further concerns.
NRC issued inspection report 50-259/89-04, 50-260/89-04, and 50-296/89-04 on January 30,
- 1989, which detailed concerns resulting from this event.
NRC and TVA management discussed these issues at an enforcement conference on February 2, 1989.
TVA responded to NRC report 89-04 in a letter dated March 1, 1989.
As a result of the discussions with TVA, responses provided by TVA, and further inspection activity, NRC issued the subject report detailing its findings resulting from this event.
The report cited TVA with three violations.
r DIi t 11.1'-"-.>>
An Equat Opportunity Employer Wa-8/
U.S. Nuclear Regulatory Commission AU8 L4 'ilP)9 Enclosure 1 provides TVA's response to the these violations.
A list of commitments is provided in enclosure 2.
'f you have any questions, please telephone Patrick P. Carier at (205) 729-3570.
Very truly yours, TENNESSEE VALLEY AUTHORITY Mark O. Medford, Vice President and Nuclear Technical Director Enclosures cc (Enclosures):
Ms.
S.
C. Black, Assistant Director for Projects TVA Projects Division U.S.
Nuclear Regulatory Commission One Nhite Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Mr. B. A. Hilson, Assistant Director for Inspection Programs TVA Projects Division U.S.
Nuclear Regulatory Commission Region II 101 Marietta Street, Nl<, Suite 2900 Atlanta, Georgia 30323 NRC Resident Inspector Browns Ferry Nuclear Plant Route 12, Box 637
- Athens, Alabama 35609-2000
ENCLOSURE 1
'e
RESPONSE
BROGANS FERRY NUCLEAR PLANT (BFN)
NRC INSPECTION REPORT NOS. 50-259/89-18, 50-260/89-18, AND 50-296/89-18 LETTER FROM B. A.
HILSON TO 0.
D.
KINGSLEY, JR.
DATED JULY 13, 1989 Violation A Technical Specification 6.8.1.1.a requires that written procedures shall be established and maintained for the applicable procedures in Appendix A of Regulatory Guide 1.33, Revision 2, February 1978.
This includes refueling procedures.
TVA Nuclear Quality Assurance Manual (NQAM), Part 2, Section 1.1, Paragraph 3.2.2 required that fuel handling procedures for core loading provide for continuous monitoring of the neutron flux throughout core loading.
Contrary to the above, the core loading procedures (2-GOI-100-3, TI-147 and the MRTI) did not contain provisions to ensure continuous monitoring of neutron flux throughout the core loading prior to beginning the loading of Unit 2 on January 3,
1989.
(Other procedure deficiencies are identified in paragraph 4 of the report.)
TVA's Res onse l.
Admission or Denial of the Alle ed Violation TVA admits the violation as stated.
2.
Reasons for the Violation if Admitted The root cause of this violation was inconsistency in the'pper tier procedural requirements (Technical Specifications, Nuclear Quality Assurance lianual (NQAM), Final Safety Analysis Report (FSAR)).
3.
Corrective Ste s Nhich Have Been Taken and Results Achieved Several plant procedures were revised after NRC raised concerns about the fuel loading procedures.
These revisions included 2-GOI-100-3, "Refueling Operations,"
and 2-TI-147, "Fuel Loading After a Complete Core Unload."
These are the primary procedures used by Operations and Reactor Engineering personnel during fuel loading activities.
Both procedures have been revised to require a minimum count rate and signal to noise ratio for the Source Range Monitors (SRM)/Fuel Loading Chambers (FLCs).
2-TI-147 was written to be specific to the completion of the unit 2, reload 5 operation.
The revised procedures have been used and the unit 2
reload completed without any errors or additional problems/concerns.
Enclosure 1
Page 2 of 6 Technical specification changes were submitted to NRC on June 20, 1989, to delete sections 3.10.B.l.b.2 and 3.10.B.l.b.3 which had allowed fuel loading without continuous core monitoring.
A Boiling Hater Reactor (BNR) Owners Group subcommittee is being formed to address reactivity controls.
In addition, the Electric Power Research Institute is performing a study of BNR fuel loading practices for the purpose of recommending generic guidelines.
TVA will remain cognizant of these studies and implement their recommendations as deemed appropriate.
4.
Corrective Ste s Nhich Hill Be taken to Avoid Further Violations The applicable portion of the NQAM will be reviewed and revised as necessary to ensure consistency with the revised fuel loading technical specifications'dditional revisions wi.ll be made to 2-GOI-100-3 and 2-TI-147 to clarify conditions which require the suspension of core loading, to clarify the actions/approvals necessary to resume core loading following suspension, and to be consistent with the revised fuel loading technical specifications.
5.
Date Nhen Full Com liance Hill Be Achieved Revisions to the NQAM, 2-GOI-100-3, and 2-TI-147 as described above will be completed before the next refueling operation.
Violation B
10 CFR 50.59(a)(2) states that a proposed change shall be deemed to involve an unreviewed safety ques'tion if the margin of safety as defined in the basis for any technical specification is reduced.
Technical Specification Basis 3.10.A states that refueling interlocks reinforce operational procedures that prohibit taking the reactor critical.'he margin of safety is provided by both the interlocks and the procedures.
Contrary to the above the licensee did not identify that their scheme for reloading the Unit 2 core for Cycle 6 on January 3,
1989 constituted an unreviewed safety question in that the reloading procedures were not adequate, thereby reducing the safety margin.
TVA's Res onse 1.
Admission or Denial of the Alle ed Violation TVA denies that a violation of 10 CFR 50.59(a)(2) occurred.
Enclosure 1
Page 3 of 6 Reasons for the Denial As discussed in the previous response to NRC on this subject dated March 1,
- 1989, TVA accepts full responsibility for not adequately monitoring the core during the unit 2 core reload activities.
TVA recognizes that
,neutron monitoring is an important part of any core loading activity and that the reload procedures were deficient in this regard.
- However, TVA does not believe that an unreviewed safety question existed.
- Hence, there was no violation of 10 CFR 50.59
'efore fuel load, TVA reviewed revisions to the reload procedures in accordance with the BFN plant procedures implementing 10 CFR 50.59.
As documented in an attachment to the January 26, 1989 Licensee Event Report addressing the circumstances of reload, TVA subsequently performed a
safety evaluation of the loading of 74 fuel assemblies in the unit 2 core without continuous SRM monitoring.
This safety evaluation demonstrated that no unreviewed safety question existed.
The safety evaluation reconfirmed that inadvertent criticality is not credible given the engineered safeguards and core design
- and, therefore, the reload without core monitoring did not increase the probability or consequences of any accident previously analyzed.
Also, in the bases for technical specification 3.10, the only margin of safety addressed is the minimum SRM count rate during startup required to assure that the assumptions of the rod drop accident are met.
The core loading was accomplished in the refuel mode (only one control rod withdrawal possible) and with the SRM downscale rod block (less than 3 cps) operable precluding any control rod withdrawal.
Therefore, no margin of safety was reduced.
The staff concludes in Inspection Report 89-18 that an unreviewed safety question did exist in that the margin of safety as defined in the technical specification bases was decreased because the basis for technical specification 3.10.A states that during core alterations the margin of safety is provided by both refueling interlocks and operating procedures.
In the staff's view, the procedures were deficient with respect to core monitoring.
- Thus, the staff concludes that the margin of safety was reduced.
e TVA disagrees with this conclusion.
As confirmed by TVA's safety evaluation, the practice of core monitoring is not required to preclude refueling accidents.
Inadvertent criticality is prevented during core alterations by the margin of safety provided in the core design and through refueling interlocks.
The BFN FSAR evaluation of refueling accidents and abnormal operational transients does not take credit for continuous SRM neutron flux monitoring to preclude inadvertent criticality.
Therefore, despite the noted areas for improvement in the procedures with respect to core monitoring, no actual margin of safety
0
Enclosure 1
Page 4 of 6 relied upon in the FSAR was reduced.
SRN neutron flux monitoring during refueling serves, in these circumstances, only as an additional level of assurance over and above the primary design factors which in fact preclude inadvertent criticality.'n
- addition, in this case it is important to recognize that TVA's reload procedures complied with an existing, approved technical specification and with what TVA determined to be the intent of the Staff's safety evaluation approving this technical specification.
It should be noted that similar technical specifications were approved on other dockets during the same timeframe.
Specifically, TVA began loading the unit 2 core in accordance with technical specification 3.10.B.l.b.2.
TVA loaded the fuel starting from the center of the core, spiraling outward.
The SRMs in this sequence do not provide continuous observable monitoring of the core,.at least until a sufficient number of assemblies are loaded to overcome neutron attenuation because of the distance between the fuel and the neutron detectors.
No minimum SRM count rate is specified in technical specification 3.10.B.l.b.'2 or the safety evaluation to support that technical specification.
Therefore, TVA reasonably concluded (and continues to conclude) that it was following an authorized method to load fuel.
TVA submits that a
10 CFR 50.59 violation cannot occur where its actions were consistent with approved technical specifications and with a reasonable interpretation of the safety evaluations supporting the technical specifications.
In addition, in such circumstances enforcement action is not appropriate.
In this regard, reference should be made to S'ection 3.8 of NSAC 125 "Guidelines for 10 CFR 50.59 Safety Evaluations" (final, June 1989).
In accordance with this discussion, TVA submits that the des~<en features that preclude inadvertent criticality establish the "acceptance limits" and the margin of safety that cannot be changed without prior NRC approval.
Assuming TVA's procedures somehow reduced the assurance of safety in this case, a
change in this margin of safety above the acceptance limit would still not be an unreviewed safety question.
Enclosure 1
3.: Corrective Sie s Hhich Have Been Taken and Results Achieved Page 5 of 6 As described in our response of March 1,
- 1989, TVA has taken and planned many specific actions, both immediate and longer term, to address the
'issues raised by the BFN unit 2 reload.
For example, TVA completed a
short-term technical specification assessment and concluded that no immediate technical specification changes in the refueling/fuel load area were needed before resuming fuel load.
However, there were several items requiring the addition of administrative controls.
These controls were implemented before resumption of fuel load.
In addition, the reload sequence was incorporated into a modified refueling procedure similar to that used for initial core loading.
The unit 2 reload was completed without any errors or additional concerns.
Technical specification changes were submitted to NRC on June 20, 1989, to delete sections 3.10.B.l.b.2 and 3.10.B.l.b.3 which had permitted fuel loading without continuous core monitoring.
In conclusion, TVA recognizes, as stated previously, that the reload procedures did not ensure continuous response of the SRMs/FLCs to core neutrons and that the engineers may not have properly questioned procedures and technical specifications in carrying out the fuel load.
- However, these inadequacies do not constitute a violation of 10 CFR 50.59(a)(2).
Therefore, while committed to remedying the underlying problems and to resolving the circumstances that led to this occurrence, TVA does noi agree that a
10 CFR 50.59 violation occurred.
Violation C Technical Specifications 6.5.3.1 and 6.5.3.3 require that changes to procedures such as operating and-refueling procedures be subjected to a cross disciplinary review if necessary.
SDSP-7.4, Onsite Technical Review of Procedures, Section 6.1.4 requires that a
cross disciplinary review shall be performed when the procedure revision affects the conduct of operation of other plant groups.
Contrary to the above, procedures 2-GOI-100-3, Revision 2; 2-GOI-100-3, Revision 3;
and 2-0I-74, Temporary Change 10 each involved changes that were not reviewed by the additional plant groups affected by the changes.
TVA's Res onse l.
Admission or Denial of the Alle ed Violation TVA admits the violation.
Enclosure 1
Page 6 of 6 2.
Reasons for the Violation if Admitted This violation was caused by failure to follow plant procedures.
Site Director Standard Practice (SDSP) 7.4, "Procedure Review," required the technical reviewer to determine if a cross disciplinary review was required for new procedures or revisions to procedures.
In the cases cited in this violation, the technical reviewers should have determined that cross disciplinary review was necessary.
3.
Corrective Ste s Hhich Have Been Taken and Results Achieved The individual who performed the technical reviews of 2-GOI-100-3 revision 3 and OI-74 temporary change 10 is no longer employed at TVA.
The individual who performed the technical review of 2-GOI-100-3 revision 2 has been counseled on the importance of ensuring adequate cross disciplinary reviews.
Both these individuals worked for Operations.
SDSP 7.4 was revised on April 25, 1989, to require that a comprehensive procedure verification review checklist be completed for intent changes to safety-related procedures.
On the first page of that checklist, the reviewer must answer a question concerning whether cross disciplinary review is required.
.In a letter to all site employees dated March 21,
- 1989, the plant manager discussed the requirements for cross disciplinary reviews and the three examples mentioned in this violation, stressing the fact that individuals who are revising procedures must consider other organizations that are affected by procedure" changes and obtain their concurrence.
4.
Corrective Ste s Hhich Hill Be Taken to Avoid Further Violations Operations personnel presently involved in the preparation and revision of procedures wi 11 be provided with a copy of this violation response by September 1,
1989.
5.
Date Nhen Full Com liance Hill Be Achieved September 1,
1989
Violation A ENCLOSURE 2
RESPONSE
NRC INSPECTION REPORT NOS. 50-259/89-18, 50-260/89-18, AND 50-296/89-18 LETTER FROM B. A.
HILSON TO O.
D.
KINGSLEY, JR.
DATED JULY 13, 1989 List of Commitments 1.
The applicable portion of the NQAM will be reviewed and revised as necessary to ensure consistency with the revised fuel loading technical specification before the next refueling operation.
2.
Additional revisions will be made to 2-GOI-100-3 and 2-TI-147 to clarify conditions which require the suspension of core loading, to clarify the actions/approvals necessary to resume core loading following suspension, and to be consistent with the revised fuel loading technical specifications before the next refueling operation.
Violation C I
1.
Operations personnel presently involved in the preparation and revision of procedures will be provided with a copy of this violation response by September 1,
1989.