ML20116F062
| ML20116F062 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 04/17/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20116F056 | List: |
| References | |
| NUDOCS 8504300544 | |
| Download: ML20116F062 (5) | |
Text
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UNITED STATES
[
g NUCLEAR REGULATORY COMMISSION 5
- j WASHINGTON, D. C. 20555
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT N0. 117 TO LICENSE NO. DPR-49 IOWA ELECTRIC LIGHT AND POWER COMPANY CENTRAL IOWA POWER COOPERATIVE CORN BELT POWER COOPERATIVE DUANE ARN0LD ENERGY CENTER DOCKET NO. 50-331
1.0 INTRODUCTION
By a letter dated August 17, 1984, the Iowa Electric Light and Power Company (the licensee /IELP) submitted an application to amend the Duane Arnold Energy Center (DAEC) Technical Specifications. The changes were proposed to support the DAEC reload and operation for Cycle 8, and to incorporate administrative changes reflecting revision to figure numbers, table of contents, references, and correction of errors.
During Cycle 8, the licensee proposes to add to the reactor core new types of fuel bundles which are similar to the other fuel except that a thin Zirconium liner has been added to the inner surface of the cladding to reduce cladding failures due to pellet clad interactions. The use of the barrier fuel does not significantly affect the thermal hydraulic performance of the fuel. Based on the analysis of the design basis Loss-of-Coolant Accident (LOCA) and the analysis of the transients, the licensee proposes to revise the Technical Specifications to change (1) Maximum Average Planar Linear Heat Generation Rate (MAPLHGR), (2) Minimum Critical Power Ratio (MCPR) operating limits for the facility, and (3) identify the barrier type fuel to be used during Cycle 8.
The proposed changes are intended to assure that the fuel performance limits and margins specified in the Final Safety Analysis Report (FSAR) are maintained, and the barrier fuel identified in the Technical Specifications.
The licensee has also proposed miscellaneous administrative changes to achieve consistency throughout the Technical Specifications, update references, and correct typographical errors. Most of these changes reflect the Cycle 8 reload.
2.0 EVALUATION The staff review of the licensee's August 17, 1983 submittal is summarized as follows:
Fuel Mechanical Design The fresh fuel which is to be loaded into DAEC for Cycle 8 is of the standard General Electric reload design. This fuel is described in hR i
P
Reference 3.
That reference has been approved for such use and we conclude that no further review of the fuel design is required. The licensee, in a separate action, proposes to install five lead test assemblies in the core for Cycle 8.
That proposal is the subject of a separate etaluation.
Nuclear Design The nuclear design of the Cycle 8 reload core has been performed with 4
methods and techniques that are described in Reference 3.
The results of the analyses are given in Reference 1.
Those results are within the range of those usually encountered for BWR reloads and are acceptable.
In particular, the shutdown margin is greater than 0.01 in K and the Standby Liquid Control System is capable of providing a sRNdown K These results are acceptable and since they have been obtaiRb of 0.97.
by previously approved methods, we conclude that the nuclear design of the Cycle 8 reload core is acceptable.
Thermal Hydraulic Design The thermal hydraulic analysis of the Cycle 8 core was performed with methods and techniques described in Reference 3.
Analyses were done at a 1
power level of 1658 thermal megawatts with the assumption of an extended load line limit.
A safety limit value of 1.07 for the core-wide minimum critical power ratio is used for Cycle 8.
This value is generic for BWR reloads and is acceptable for Cycle 8.
The operating limit MCPR is obtained by performing analyses of anticipated events in order to determine the reduction in critical power (ACPR) resulting from them. Analysis methods, including treatment of i
uncertainties, are described in Reference 3.
The operating limit MCPR is established by adding the largest value of ACPR to the safety limit value.
i The stability analysis has been performed for the extended load line limit and at 1658 thermal megawatts. The effect of extended load line operation 4
j and single loop operation for Cycle 8 will be addressed in a separate evaluation.
Transient and Accident Analyses Transient and accident analysis methods, described in Reference 3, are the same methods that have been used in previous cycles for DAEC and are acceptable for Cycle 8.
The one-dimensional transient code ODYN has been used to analyze the pressurization events. The licensee has elected to use ODYN Option B in which measured rod scram times are used.
For this option the pressurization events are not limiting.
If Option A scram times are used, the Load
Rejection Without Bypass event is limiting. Use of the Option B mode is widespread in boiling water reactors and its use is acceptable for DAEC.
The licensee has elected to use the generic analysis results for the rod withdrawal event. This had been approved by the staff for BWR reloads and is acceptable for DAEC. The fuel misorientation event is the limiting event for Option B and establishes the operating limit MCPR for Cycle 8 of 1.26.
The analysis of this event has been performed by the approved methods of Reference 3 and is acceptable.
The loss-of-coolant accident (LOCA) has been reanalyzed for Cycle 8 of DAEC at a power of 1691 thermal megawatts (1658 X 1.02) as required by 10 CFR 50.46 and with a full core of assemblies having drilled lower tie plates.
The analysis has been approved in a separate evaluation (Amendment No. 115).-
A cycle specific rod drop accident analysis has been performed for Cycle 8 of DAEC for the hot shutdown case since the parameters of the generic analysis were not bounding for this case. The result shows that the NRC limit of 280 calories per gram for the peak enthalpy is satisfied. This meets our criterion for the rod drop accident event.
Technical Specifications The changes to be made to the Technical Specifications are due to the following circumstances:
1.
Removal of the last of the 8X8 fuel from the core.
2.
Reanalysis of the Loss-of-Coolant Accident with a full core of assemblies having drilled lower tie plates.
3.
Reanalysis of the transients and accidents for Cycle 8.
4.
Use of the ODYN Option B scram times.
5.
Elimination of the requirement for end-of-cycle scram testing.
6.
Change of the format for the MCPR values from the present tabular to a graphical presentation.
7.
Administrative changes reflecting the above changes and correction of errors.
Each of these items is discussed below:
Removal of 8X8 Fuel The Technical Specifications are changed in several places to remove references to and operating limits for the 8X8 fuel. These changes are editorial in nature and are acceptable.
LOCA Reanalysis The new curves of MAPLHGR as a function of exposure (Figures 3.12-6 and 3.12-8) have been obtained from the approved LOCA reanalysis and are acceptable.
w r
.. Use of ODYN Option B and MCPR Specification Format The minimum critical power ratio Technical Specification has been rewritten to accommodate use of the ODYN Option B analysis (Reference 3). The tabular form of the permitted value of MCPR has been replaced with a curve of MCPR as a function of the parametert'. The ODYN transient analyses have been performed for both the Option B scram time and the Option A (Technical Specification) scram time in order to establish end points for the curves.
The curve of MCPR as a function of r is consistent with the results of the safety analyses and is acceptable. The format of the Technical Specification is similar to that of other plants using Option B and is acceptable.
Reanalysis of Transients and Accidents for Cycle 8 The limiting transient for low values of (scram times near those for Option B) is the fuel misorientation event. The Technical Specification value of MCPR is consistent with the results for this event and is acceptable.
End-of-Cycle Scram Testing In order to verify that scram time degradation was not occurring between refueling outages DAEC was required, by Amendment No. 54, to perform end-of-cycle scram testing. The additional testing was required to be conducted only through Cycle 6.
Therefore, the deletion of this requirement for Cycle 8 is acceptable.
As a result of our review, we conclude that the proposed reload and-Technical Specification changes are acceptable. This conclusion is based on the following:
1.
Previously approved analysis methods and techniques are employed.
2.
The consequences of the transients and accidents which are affected by the reload are acceptable for Cycle 8.
3.
The administrative revisions to the Technical Specifications have been found to be acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
S This amendment involves a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, this amendment meets the eligibility criteria
=
.s-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 with the issuance of this amendment.
4.0 CONCLUSION
We have 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, and (2) such activities will be conducted in compliance with the Commission's regulations, and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
5.0 REFERENCES
1.
General Electric Report 23A1739 Supplemental Reload Licensing Submittal for Duane Arnold Energy Center Unit 1, Reload 7, June 1984.
2.
General Electric Report NEDO 21082-03, loss-of-Coolant Accident Analysis Report for Duane Arnold Energy Center (Lead Plant), June 1984 3.
NEDE-24011-P-A-6, General Electric Standard Application for Reactor Fuel, April 1983.
Principal Contributor:
W. Brooks Dated: April 17,1985 O
W i
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