ML20203J333
| ML20203J333 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 02/17/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20203J330 | List: |
| References | |
| NUDOCS 9902230363 | |
| Download: ML20203J333 (5) | |
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UNITED STATES s
j NUCLEAR REGULATORY COMMISSION t
WASHINGTON, D.C. 30666 0001
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 225 TO FACILITY OPERATING LICENSE NO. DPR-49 IES UTILITIES INC.
CENTP.AL IOWA POWER COOPERATIVE CORN BELT POWER COOPERATIVE DUANE ARNOLD ENERGY CENTER DOCKET NO. 50-331
1.0 INTRODUCTION
On January 20,1999, IES Utilities Inc. (the licensee) reported to the staff in a teleconference that the Duane Arnold Energy Center (DAEC) was not in compliance with Technical Specification (TS) Surveillance Requirement (SR) 3.8.1.7, related to diesel generator (DG) testing, and that a reactor shutdown would be required in accordance with TS 3.8.1, Condition E. The licensee stated that the cause of the noncompliance was that SR 3.8.1.7 underwent significant changes as part of DAEC's conversion to the improved TS (ITS) which were implemented on August 1,1998. Although the licensee did not intend for the basic requirements of the SR to change as a result of the TS conversion, a significant change was introduced with the adoption of the Standard TS (STS) wording of NUREG 1433, " Standard Technical Specifications, General Electric Plants BWR/4," Revision 1. Specifically, upper limits on voltage and frequency for the initial starting sequence of the DG were added which were unnecessarily conservative for a DG in an unloaded condition. This condition was recognized, subsequent to the DAEC iTS conversion, and a c.hange to the STS, Technical Specification Task Force (TSTF) change 163, Rev.2, has been approved by the NRC to correct this SR.
Therefore, the licensee concluded that it is inappropriaic to cause the plant to shut down due to a recognized deficiency in the TS.
The licensee requested that the Nuclear Regulatory Commission (NRC) exercise discretion not to enforce compliance with the actions required in SR 3.8.1.7 until an exigent TS amendment could be processed to revise G 3.3.1.7. By letter dated January 21,1999, the licensee submitted its formal reque
.a a Notice of Enforcement Discretion (NOED) pursuant to the NRC's policy regarding exercise of discretion for an operating facility set out in Section Vll.c. of the " General Statement of Policy and Procedures for NRC Enforcement Actions" (Enforcement Policy), NUREG-1600. By letter dated January 22,1999, the staff documented the issuance of the NOED for the DAEC. The NOED had been issued verbally on January 20,1999, after the staff concluded that the licensee's technical basis for the request was satisfactory. By letter 9902230363 990217 PDR ADOCK 05000331 P
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dated January 22,1999, the licensee submitted a request for an exigent TS amendment to revise SR 3.8.1.7. The proposed change would revise SR 3.8.1.7 to better match plant conditions during DG testing by clarifying which voltage and frequency limits are applicable during the transient and steady-state portions of the DG start.
2.0 EVALUATION Currently DAEC TS SR 3.8.1.7 requires the licensee to:
Verify each DG starts from standby condition and achieves, in.< 10 seconds, voltage > 3744V and 5 4576V and frequency 2 59.5Hz and5 60.5Hz."
The licensee's proposal would change SR 3.8.1.7 to:
Verify each DG starts from standby condition and achieves:
- a. in 510 seconds, voltage 2 3744V frequency 2 59.5Hz; and
- b. steady state, voltage 2 3744V and5 4576V and frequency 2 59.5Hz and <_ 60.5Hz.
As part of implementing the proposed amendment, the licensee would also modify the bases for SR 3.8.1.7 to add a statement regarding periodically monitoring and trending the time for the DG to reach steady-state operation in order to identify degradation of govemor and voltage regulator performance.
The licensee's proposed change would revise SR 3.8.1.7 to better match plant conditions during testing. This surveillance test is performed with the DG unloaded, so that the DG initially over-shoots its target nominal voltage and frequency during testing. In an actual event, the DG would be almost immediately loaded once minimum voltage and frequency requirements are met, thereby limiting the over-shoot. The revision changes the SR 3.8.1.7 criteria to clarify which voltage and frequency limits are applicable during the transient and steady-state portions of the DG start.
This proposed change would not affect the DG's ability to supply the minimum voltage and frequency required within 10 seconds or the steady-state voltage and frequency required by the Updated Final Safety Analysis Report (UFSAR) analysis. The DGs will continue to perform their intended safety function, in accordance with the DAEC accident analysis. The Loss of Offsite Power-Loss-of-Coolant Accident (LOOP-LOCA) test will still be performed to demonstrate DG operability in conditions which are more representative of accident conditions (loaded in the actual time sequence for loading).
4 As discussed above, subsequent to the DAEC ITS conversion, this change to SR 3.8.1.7 was reviewed by the staff as a generic change to the STS. The staff approved TSTF change 163, Rev.2, which incorporated the proposed change to SR 3.8.1.7.
The staff has reviewed the licensee's proposed license amendment and finds that the proposed change will better match plant conditions during testing and the proposed change is consistent
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.s with the change to the STS approved by the staff in TSTF change 163, Rev.2. The staff, therefore, finds the licensee's proposed change acceptable.
3.0 EXIGENT CIRCUMSTANCES
The Commission's regulations,10 CFR 50.91, contain provisions for issuance of amendments when the usual 30-day public notice period cannot be met. One type of special exception is an exigency. An exigency is a case where the staff and licensee need to act promptly and the staff has determined that the amendment involves no significant hazards considerations.
Under such circumstances, the Commission notifies the public in one of two ways: by issuing a Federal Reaister notice providing an opportunity for hearing and allowing at least two weeks for public comments, or by issuing a press release discussing the proposed changes, using the local media. In this case, the Commission used the first approach.
The licensee submitted the request for amendment on January 22,1999, it was noticed in the Federal Reaister on Februsry 1,1999 (64 FR 4902), at which time the staff proposed a no significant hazards considaration determination. In its application, the licensee requested that the amendment be processed as an exigent request pursuant to 10 CFR 50.91(a)(6). The exigency was created by the existing TS surveillance, SR 3.8.1.7, containing inappropriate acceptance criteria which the DG is not designed to meet and which is overly conservative with respect to the DAEC UFSAR requirements for the DGs. This acceptance criteria was incorporated into the TS just prior to the approval of DAEC's conversion to Standard TS (NUREG 1433). The licensee did not intend that the basic requirements of this testing be different from those contained in the former custom TS (CTS 4.8.A.2.a.2). However, a significant change was introduced due to the adoption of the wording of NUREG-1433.
Because this change was not recognized at that time, the plant procedure for the new SR did not correctly implement the TS. It was only recently, during the review of the Bases for this SR for another issue, that this error was recognized.
In order to continue plant operation in i aconipliance with SR 3.8.1.7, enforcement discretion was verbally request by the licensee and granted by the NRC on January 20,1999. The NOED, which was documented in a January 22,1999, letter, granted enforcement discretion from the requirements of SR 3.8.1.7 until an exigent TS amendment to revise SR 3.8.1.7 is processed.
Accordingly, pursuant to 10 CFR 50.91(a)(6), the Commission has determined that the licensee used its best efforts to make a timely application and that exigent circumstances exist in that the licensee and the Commission must act quickly to prevent an unnecessary plant shutdown.
Further, the Commission has determined that the exigency could not have been avoided and that the licensee did not create the exigency.
4.0 FINAL NO SIGNIFICANT HAZARDS CONSIDERATION
DETERMINATION The Commission's regulations in 10 CFR 50.92 state that the Commission may make a final determination that a license amendment involves no significant hazards considerations if operation of the facility in accordance with the amendment would not (1) involve a significant
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4-f increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a matgin of safety.
Operation of the facility in accordance with the proposed amendment will not involve a significant increase in the probability or consequences of ar. accident previously evaluated.
The safety function of the DG is to provide AC power to required safety systems during any
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LOOP event. The limiting design-basis accident is the LOCA with concurrent LOOP (LOOP-l LOCA). This proposed amendment would modify a DG SR and would not impact the offsite AC distribution system; therefore the probability of any LOOP event, including the LOOP-LOCA will not be significantly increased. This change will not affect the DG's ability to supply the minimum voltage and frequency required within 10 seconds or the steady-state voltage and frequency
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required by the UFSAR. The DGs will continue to perform their intended safety function, in i
j accordance with the DAEC accident analysis.
i Operation of the facility in accordance with the proposed amendment will not create the possibility of a new or different kind of accident from any accident previously evaluated. This change does not introduce any new modes or methods of plant operation. The proposed amendment would change the SR 3.8.1.7 criteria to clarify which voltage and frequency limits l'
are applicable during the transient and steady-state portions of the DG start. No changes are being made in how the system actually operates or is physically tested.
l Cperation of the facility in accordance with the proposed amendment will not involve a significant reduction in a margin of safety. The DGs will continue to perform their intended safety function, in accordance with the DAEC accident analysis. The revised test criteria are a better match for the tested condition (unloaded). DG operability in conditions that are more representative of postulated accident conditions (loaded in the actual time sequence assumed in the accident analysis) are demonstrated by other SRs which are not affected by this proposed amendment.
Based on the above considerations, the staff concludes that the amendment meets the three criteria of 10 CFR 50.92. Therefore, the staff has made a final determination that the proposed amendment does not involve a significant hazards consideration.
5.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Iowa State official was notifed of the proposed issuance of the amendment. The State official had no comments.
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6.0 ENVIRONMENTAL CONSIDERATION
S This amendment changes a surveillance requirement. The staff has determined that the i
amendment involves no significant increase in the amounts, and no significant change in the types, of any effluent that may be released offsite, and that there is no significant increase in 1
individual or cumulative occupational radiation exposure. The Commission has made a final finding that the amendment involves no significant hazards consideration. Accordingly, the i
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,e amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection witn the issuance of the amendment.
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7.0 CONCLUSION
l The staff has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: R. Laufer Date:
February 17, 1999 i
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