ML20246N041
| ML20246N041 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 03/17/1989 |
| From: | Thompson H NRC OFFICE OF THE EXECUTIVE DIRECTOR FOR OPERATIONS (EDO) |
| To: | CAROLINA POWER & LIGHT CO. |
| References | |
| EA-88-088, EA-88-88, NUDOCS 8903270290 | |
| Download: ML20246N041 (9) | |
Text
b il
.o s =
1 e1 u
u UNITED STATES NUCLEAR REGULATORY COMMISSION O
.i In the Matter of
)
Docket No. 50-261 Carolina Power & Light Company
)
License No. DPR-23 H. B. Robinsoa Steam Electric
)
EA 88-88 l
Generating Plant Unit 2 ORDER IMPOSING CIVIL MONETARY PENALTY I
Carolina Power & Light Company (CP&L/ licensee) is the holder of Operating License No. DPR-23 issued by the Nuclear Regulatory Commission (Commission /NRC) on July 31, 1970. The license authorizes the licensee to operate the H. B.
Robinson Steam Electric Plant, Unit No. 2, in accordance with the conditions; specified therein.-
g
?
II NRC inspections of the licensee's activities under the license were conducted on January 11 - February 10, 1988, with a followup inspection conducted February 11 - March 10,1988, at the H. B. Robinson Steam Electric Plant, Unit No. 2, Hartsville, South Carolina. The results of these inspections indicated that the licensee had not conducted its activities in full compliance with NRC requirements. A written Notice of Violation and Proposed Imposition of Civil Penalty was served upon the licensee by letter dated June 15, 1988. The Notice stated the nature of the violation, th provisions of the NRC's requirements that the licensee had violated, and the amount of the civil penalty proposed for the violation. The licensee responded to the Notice of Violation and f0 nowuo q 9g].
O
. Proposed Imposition of Civil Penalty by lette: dated July 15, 1988 denying the violation and requesting full mitigation of the civil penalty.
1 III After consideration of the licensee's response and the statements of fact, explanation, and argument for mitigation contained therein, the Deputy Executive Director for Nuclear Materials Safety, Safeguards, and Operations Support has determined, as set forth in the Appendix to this Order, that the violation occurred as stated without considering scenarios (2) and (3) and that the penalty proposed for the violation designated in the Notice of Violation and' Proposed Imposition of the Civil Penaity, as amended by withdrawing two failure scenarios ((2) and (3)), should be imposed.
IV In view of the foregoing and pursuant to Section 234 of the Atomic Energy Act i
of 1954, as amended (ACT), 42 U.S.C. 2282 and 10 CFR 2.205, IT IS HEREBY ORDERED THAT:
The licensee pay a civil penalty in the amount of Fifty Thousand Dollars ($50,000) within 30 days of the date of this Order, by check, draft, or money order, payable to the Treasurer of the United States and mailea to the Director, Office of Enforcement, U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, D.C. 20555.
'e
. )
y l
The licensee may request a hearing within 30 days of the date of this Order. A request for a hearing shall be clearly marked as a " Request for an Enforcement l
Hearing" and shall be addressed to the Director, Office of Enforcement, U.S. Nuclear Regulatory Cosmission, ATTN: Document Control Desk, Washington, D.C. 20555, with a copy to the Regioral Administrator, Region II, 101 Marietta Street, N.W., Atlanta, Georgia 30323, and a copy to the NRC Resident Inspector, H. B. Robinson Steam Electric Plant.
4 If a hearing is requested, the Connission will issue an Order designating the time and place of the hearing.
If the licensee fails to request a hearing within 30 days of the date of this Order, the provisions to this Order shall be effective without further proceedings.
If payment has not been made by that time, the matter may be referred to the Attorney General for collection.
In the event the licensee requests a hearing as provided above, the issues to be considered at such hearing shall be:
(a) whether the licensee was in violation of the Connission's requirements as set forth in the Notice of Violation and Proposed Imposition of Civil Penalty referenced and amended in Section III above, and i
e
. (b) whether, on the basis of such violation, this Order should be sustained.
FOR THE NUCLEAR REGULATORY COMMISSION WA' Hug L. Thomps
,J.
D ty Executive D r tor for Nuclear Materials afety, Safeguards, and Operations Support Dated at Rockville, Maryland this/F]dayofMarch1989-l 1
I APPENDIX l
l EVALUATION AND CONCLUSIONS On June 15, 1988, a Notice of Violation and Proposed Imposition of Civil Penalty (Notice) was issued for a violation identified during NRC inspections.
Carolina Power & Light Company (CP&L) responded to the Notice on July 15, 1988.
In its response, the licensee denies the violation as stated in the Notice, and requests mitigation of the proposed civil penalty. The NRC's evaluation and conclusion regarding the licensee's arguments are as follows:
I.
Restatement of Violation "10 CFR 50.46 (a)(1) requires that emergency core cooling system (ECCS) cooling performance be calculated in accordance with an acceptable evalua-tion model.
10 CFR Part 50, Appendix K, sets forth standards for an acceptable model.
Appendix K, Section D.1., " Single Failure Criterion" requires that in the accident evaluation the combination of ECCS subsystems assumed to be operative be those available after the most damaging single failure of ECCS equipment has taken place.
Contrary to the above, as of January 29, 1988, the combination of ECCS subsystems assumed to be operative in the evaluation model in the H. B. Robinson Undated
- Safety Analysis Report (USAR) did not reflect certain more damaging single failures of ECCS equipment, particularly the Safety Injection (SI) System.
Certain single failures could have rendered two of the three SI pumps inoperable while the H. B. Robinson USAR evalua-tion model assumed ct most one SI pump being inoperable after the most damaging single failure.
The four scenarios in which the SI safety function could have been lost only leaving one SI pump operable are (1) a single failure of the sequencer relay in the safeguard sequencing logic, (2) a single failure of the emergency diesel generator (EDG) field flash circuit after loss of offsite power and loss-of-coolant conditions, (3) a single failure of the DC control power during safeguard sequencing, and (4) a single active failure in the EDG system controls."
Summary of licensee's Response to Violation The licensee denies the violation occurred.
CP&L believes it was in compliance with 10 CFR 50.46(a)(1) and 10 CFR Part 50, Appendix K.
CP&L states that analyses submitted to demonstrate compliance were within the scope outlined in Section 3.1 of the Updated Final Safety Analysis Report (UFSAR), "Conformance with General Design Criteria," specifically Sec-tion 3.1.2.41, which requires that the Engineered Safety Features (ESF) perform their intended functions while accommodating the failure of any
- This was a typographical error in the original Notice which should have read
" Updated" rather than " Undated."
Appendix singleactivecomponent(emphasisadded). Thus, a failure of one Emergency Diesel Generator was identified by the licensee as the most limiting single active failure. The licensee further states that " failures of batteries and wires breaking are failures of passive components which are outside the scope of the original design basis." Subsequently, the Appendix K model 1
and analyses were submitted to the Atomic Energy Commission (AEC) in November 1974; and the AEC issued the Order for Modification of License on December 27, 1974 accepting the diesel failure as the worst-case single failure of ECCS performance. As a result of these documents and the lack of any additional questions from the AEC, the licensee asserts that it concluded that the original single failure scenarios, as accepted by the AEC, were appropriate.
In July 1984, a new single failure analysis as part of the Appendix K submittal for Technical Specification revisions associated with Cycle 10 operations was submitted and again the NRC accepted the appropriateness of the single failure scenarios used for Appendix K analysis in the SER for Licensee Amendment 87.
NRC Evaluation 10 CFR 50.46 and Appendix K require that ECCS cooling performance be calculated in accordance with an acceptable evaluation model. Appendix 5K sets forth certain required. features of evaluation models that include j an analysis of possible failure modes of ECCS equipment and their effect on ECCS performance. The combination of ECCS subsystems allowed to be assumea operable are those available after the most damaging single failure of ECCS equipment has taken place. Appendix K has never distinguished between active and passive failures in determining the most damaging single failure.
10 CFR 50.46 further requires that the ECCS cooling performance design comply with Criterion 35 of 10 CFR Part 50, Appendix A, General Design Criteria, to assure that the safety system function can be accomplished, dssuming a single failure. The applicable definition for single failure is contained in the Definitions and Explanations Section of Appendix A.
Fluid and electrical systems are considered to be designed against an assumed single failure if neither (1) a single failure of any active component (assuming passive components function properly), nor (2) a single failure of any passive component (assuming active components function properly), results in the loss of the capability of the system to perform its safety functions.
In other words, there is no distinction made between failures of active and passive components for electrical systems.
The Notice of Violation contains two scenarios where the failure of an active component (EDG system controls and ECCS sequencer relay) could render two of the three 50 percert capacity safety injection pumps inoper-dble. The other tWo Scenarios Contained in the Notice involve a malfunc-tion of what the licensee contends are passive components in the EDG field flash circuit and DC control power, that could also render two safety injection pumps inoperable.
The licensee's response did not address the other two active component failure scenarios, and therefore did not provide any new information not already considered.
l l
Appendix The licensee's response focused on the assertion that H. B. Robinson Unit No. 2 was licensed to operate prior to the promulgation of 10 CFR 50.46 and Appendix K, and that its submitted analysis reiterated that the original ECCS design basis was a single active failure. Staff reviews of those analyses did not identify this variance from the regulations, but instead found the generic evaluation model to be appropriate and applicable for use in evaluation of the ECCS performance for H.B. Robinson Unit 2, as the sensitivity study for three-loop plant designs included a worst single failure assumption. Licensee submittals for the July 1984 Cycle 10 analysis also maintained that the ECCS was designed for a single active failure. The variance was not acted upon again, and the licensee indicates that the staff's tacit approval of consideration of only active failures may be deemed to be an implied exemption.
Because of this circumstance, for purposes of this enforcement action, the staff has decided not to focus upon the two scenarios which the licensee claims are passive failures which could render the safety injection pumps inoperable.
Resolution of passive failure design criteria will be pursued separately.
Notwithstanding the abcVe, though CP&L believes that it communicated to the NRC that the ECCS could only meet single active failures, it is the licensee's responsibility to identify the worst case single failure and to consider the need to design against such a single failure which may result in the loss of capability of a safety system to perform its intended function.I The original worst case single failures identified by CP&L were in error in that the postulated failure resulted in the inoperability of only one safety injection pump.
Subsequent evaluations found four scenarios in which the single failure could render two of the three 50 percent capacity safety injection pumps inoperable.
Each individual failure is therefore significant in itself.
II.
Summary of Licensee's Request for Mitigation The licensee states that even if the staff disagrees with CP&L's denial, that there dre extenuating circumstances per 10 CFR Part 2, Appendix C, Section V,B., that justify mitigating the proposed civil penalty in full.
CP&L argues that justification for full mitigation is based on:
1.
prompt reporting of the identified single failures to the NRC, 2.
prompt and aggressive corrective actions including shutdown of the
- plant, 3.
results of a subsequent analysis, approved by the NRC, that demonstrated that at no time did a hazard to the public exist, 4
prior good performance in providing analyses in accordance with 10 CFR 50.46, and in not previously being cited for any violation related to 10 CFR 50.46, and 5.
implementation of a formal Design Basis Reconstitution Program at H. B. Robinson.
NRC Evaluation 1.
The violation described in this enforcement action was not identified as the result of a licensee initiative.
Rather, the violation was identified as a result of an NRC request for additional information regarding the B safety injection pump auto transfer scheme (NRC letter K. Eccleston to
\\
Appendix E. Utley, January 14,1988) and subsequent inquiries by NRC inspectors on January 29, 1988 concerning plant response to certain other types of electrical system faults.
2.
On January 29, 1988, the licensee's initial corrective action, after identifying that an unanalyzed condition existed, was to initiate a plant shutdown at 10 percent per hour such that the plant would be in hot shutdown in eight hours as required by Technical Specification ACTION STATEMENT 3.0.
The licensee's review of the normal breaker configuration for powering the "B" SI pump from either of the two emergency buses revealed that realignment of the normal breaker configuration would prevent the problem. A procedure change was made, the breakers realigned, and the shutdown was terminated at 40 percent full power, with full power j
operation resumed less than six hours later. Less than six hours after i
the return to full power, the NRC Resident Inspector. requested information concerning certain other types of faults in the electrical system which could also have a potential for resulting in automatically starting only one SI pump. One of the questions dealt with what effect a loss of the "A" battery bus would have on EDG "A" after having successfully loaded, i.e., SI pumps A and B, sequenced into it. While preparing an answer to this and other questions, the licensee identified another single failure, which with the norrnal plant configuration, would also result in only one SI pump being automatically available. At the time, the licensee decided that another procedure fix, though available, was unacceptable and elected to shut down the unit until a comprehensive single failure review could be perforrned and appropriate corrective action taken. Subsequently, four scenarios were identified which required plant procedure or equipment changes.
Thus, the initial correction for an unanalyzed condition was to make a procedure change without an in-depth analysis of the issue. Although initially this provided an acceptable solution for the then 1dentitled condition, had in-depth analyses been performea initially, the additional scenarios would have been identified.
3.
The fact that subsequent analyses indicatec the need for only one of the i
three SI pumps is not a basis f or mitigation of the civil penalty in this case as it does not go to the central issue in this action; that 15, the fact that an adequate technical evaluation model did not cons 1cer all possible damaging single failures of ECCS equipment.
4.
In developing this enforcement action, the NRC considered, but reaected, escalation of the civil penalty based on the licensee's prior performance under the provisions of 10 CFR Part 2, Appendix C, V.B.3.
The NRC identi-fied a number of design deficiencies during the Safety System Functional Inspection conducted in April 1987, and noted a lack of aggressive effort by CP&L to correct those deficiencies.
5.
The policy allows mitigation to be considered when a violation is identified by a licensee audit program. The violation was not identified as a result of the referenced program activities, but rather through NRC requests for additional inforr.ation.
g a
Appendix Conclusion The staff concludes that the violation occurred as modified above by withdrawing scenarios (2) and (3) described in the violation, and that a sufficient basis for mitigation of the civil penalty has not been provided. The basis for the civil penalty in this case was the failure to comply with 10 CFR 50.46 and not solely the number of individual failure scenarios described. The remaining two single failure scenarios are a sufficient basis to warrant issuance of a civil penalty. Consequently, the proposed civil penalty of $50,000 should be imposed.
I i
i l