ML20217K958
| ML20217K958 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 03/31/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20217K951 | List: |
| References | |
| NUDOCS 9804070344 | |
| Download: ML20217K958 (3) | |
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UNITED STATES g
j NUCLEAR REGULATORY COMMISSION o
WASHINGTON, D.C. 30666 4 001 e...../
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 221 TO FACILITY OPERATING LICENSE NO. DPR-49 IES UTILITIES INC.
CENTRAL IOWA POWER COOPERATIVE CORN BELT POWER COOPERATIVE DUANE ARNOLD ENERGY CENTER DOCKET NO. 50-331
1.0 INTRODUCTION
By letter dated February 3,1998, the licensee suomitted a request for changes to the Duane Arnold Energy Center (DAEC) Technical Specifications (TS). The proposed amendment would revise the definitions of Cold Condition and Cold Shutdown and add a new section, 3.17, " Vessel Hydrostatic Pressure and Leak Testing," to the Technical Specifications to specifically allow reactor vessel hydrostatic pressure testing to be performed during plant shutdown. This proposed revision to DAEC TS is consistent with NUREG 1433, Revision 1, " Standard Technical Specifications, General Electric Plants, BWR/4."
2.0 BACKGROUND
The current DAEC TS contain no explicit exceptions to the definition of Cold Shutdown to allow performing inservice hydrostatic testing and system leakage tests required by Section XI of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code. This testing is required to be performed prior to the reactor going critical after a refueling outage. Recirculation pump operation and water solid reactor pressure vessel, as well as hydrostatic pump and control rod drive pump operation, are used to achieve the necessary temperatures and pressures required for these tests. The minimum allowable temperatures for these tests are determined from the Operating Limits Curve, TS Figure 3.6-1. These temperatures are conservatively based on the fracture toughness of the reactor vessel, taking into account anticipated vessel neutron fluence.
With increased reactor vessel fluence over time, the minimum allowable vessel temperature increases at a given pressure. Periodic updates to TS Figure 3.6-1 are performed as necessary, based upon the results of analyses ofirradiated surveillance specimens removed from the vessel. Hydrostatic pressure and leak testing will eventually a
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3.0 EVALUATION This proposed revision to DAEC TS would provide an exception to Hot Shutdown requirements, including operability of primary containment and the full complement of redundant Emergency Core Cooling Systems allowing the reactor to be considered in Cold
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Shutdown during hydrostatic or leak testing when the reactor coolant temperature is
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> 212*F. Since the hydrostatic or leak tests are performed water solid, at low decay heat values, and near Cold Shutdown conditions, the stored energy in the reactor core will be very low. Under these conditions, the potential for failed fuel and a subsequent increase in j
coolant activity above the Limiting Conditions for Operation (LCO) 3.6.B, " Coolant
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Chemir,try," limits are minimized. In addition, the secondary containment will be operable,
-l in accordance with proposed LCO 3,17, " Vessel Hydrostatic Pressure and Leak Testing,"
and will be capable of handling any airborne radioactivity or steam leaks that could occur
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during the performance of hydrostatic or leak testing.
In the event that leaks occur during the test, small system leaks would be detected by leakage inspections before significart inventory loss occurred. In the event of a large primary system leak, the reactor vessel would rapidly depressurize, allowing the low pressure core cooling systems to operate. The capability of the low pressure coolant injection and core spray subsystems, as required in Cold Shutdown by LCO 3.5, " Core and Containment Cooling Systems,".would be more than adequate to keep the core flooded under this low decay heat load condition. In addition, the required pressure testing conditions established by the proposed LCO 3.17, provioe adequate assurance that the f
consequences of a steam leak will be conservatively bounded by the consequences of the postulated main steam line break outside of primary containment.
The staff has reviewed the licensee's proposed changes and determined tnat the protection provided by normally required Cold Shutdown applicable LCOs, in addition to the secondary containment requirements required to be met by the proposed LCO 317, q
" Vessel Hydrostatic Pressure and Leak Testing," will ensure acceptable consequences during normal hydrostatic test conditions and during postulated accident conditions. The staff, therefore, finds the proposed changes acceptable.
3.0 STATE CONSULTATION
I in accordance with the Commission's regulations, the Iowa State official was notified of the proposed issuance of the amendment. The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
This amendment changes a requirement w.'th respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes a -
surveillance requirement.~ The stah'has determined that the amendment involves no i
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, 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 individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on suct: finding (63 FR 9874). Accordingly, the amendment meets the eligibility critoria 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 the amendment.
5.0 CONCLUSION
The staff has concluded, based on the considerations discussed above, that: (1) there is I
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 I
the Commission's regulations, and (3) the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
PrincipalContributors: P. Ray R. Laufer Date: March 31, 1998 t
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