ML15112B096
| ML15112B096 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 03/11/1983 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML15112B094 | List: |
| References | |
| NUDOCS 8303210013 | |
| Download: ML15112B096 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, 0. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 119 TO FACILITY OPERATING LICENSE NO. DPR-38 AMENDMENT NO. 119 TO FACILITY OPERATING LICENSE NO.
DPR-47 AMENDMENT NO. 116 TO FACILITY OPERATING LICENSE NO.
DPR-55 DUKE POWER COMPANY OCONEE NUCLEAR STATION, UNITS NOS. 1, 2 AND 3 DOCKETS NOS.
50-269, 50-270 AND 50-287 Introduction By letter dated November 12, 1982,'as revised on February 24, 1983, Duke Power Company (DPC or the licensee) proposed a change to the Otonee Nuclear Station, Units 1, 2 and 3 Technical Specifications (TSs).
This change is a revision to the reactor vessel pressure-temperature limits.
Batkground The licensee indicated that the bases for the proposed pressure-temperature limits were the material-properties data in Babcock & Wilcox (B&W)
Reports BAW-1697 and BAW-1699.
The curves for each Oconee reactor vessel are to be valid for 15 effective full power years (EFPY).
The B&W Reports BAW-1697 and BAW-1699 contain the B&W analysis of reactor vessel material surveillance capsules OC III-B and OC II-A, respectively.
These capsules are part of the B&W Owners Group Integrated Surveillance Program. As a result, the capsules were irradiated in both the Oconee and Crystal River 3 reactor vessels.
Evaluation A comparison of the materials in the Oconee 1, 2 and 3 reactor-vessels and the OC III-B and OC II-A capsules indicates that the limiting weld material in the Oconee 1, 2 and 3 reactor vessels is not contained in the OC III-B and OC II-A capsules.
The limiting material in the Oconee 1, 2 and 3 reactor vessels is weld material SA 1430, WF 24, and WF 67, respectively. The weld materials in OC III-B and OC II-A are WF 209-18 and WF 209-1A, respectively. Although tVe..weld materials in the vessel and the capsules are not identical, they were prepared'by
-'the same manufacturer, using the same type ofawtre and flux and heat treated to an equivalent metallurgical condition. As a result, the fracture toughness data from capsules OC III.-B and OC II-A moy be utilized for evaluating the proposed pressure-temperature limits.
8303210013 830311 PDR ADOCK 05000269 P
-PDR2
-2 The change in upper shelf energy (USE) and reference temperature resulting from neutron irradiation damage of the limiting materials in the OC III-B and OC II-A capsules are compared in Table 1 to the values predicted by Regulatory Guide 1.99, Rev. 1, "Effects of Residual Elements on Predicted Radiation Damage to Reactor Vessel Materials", and the values predicted by B&W Report BAW-1511P dated October 1980.
This comparison indicates that the Regulatory Guide 1.99 method for predicting change in RTNDT resulting from neutron irradiation damage is conservative. In addition, the method in Figure 13 of B&W Report BAW-1511P for predicting the change in weld material.USE properties resulting from neutron irradiation damage is more accurate than the method in Regulatory Guide 1.99.
Hence, we utilized Regulatory Guide 1.99 methodology for estimating the change in vessel material RT
, and Figure 3 in B&W Report BAW-1511P for estimating the change in reac @r vessel material USE. We believe that Figure 3 in B&W Report BAW-1511P is more accurate.than Regulatory Guide 1.99 for estimating the change in USE resulting from irradiation damage for Oconee vessel and surveillance weld materials because Figure 3 in B&W Report BAW-1511P was generated from reactor vessel surveillance weld materials similar to the Oconee vessel and surveillance weld materials, and the Regulatory Guide 1.99 curve was generated from reactor vessel weld materials utilized throughout the nuclear industry.
The USE for the Oconee beltline materials must exceed.50 ft-lbs at the 1/4 thickness location in order to meet the safety margins required by Paragraph IV.A,2 of Appendix G, 10 CFR Part 50.
Using Figure 3 in B&W Report BAW-1511P, we estimate that the limiting materials in Oconee 1, 2 and 3 reactor vessel beltlines will have USE less than 50 ft-lbs at the 1/4 thicknes location when their neutron fluence 2(E>lMeV) exceeds 5 x 101 8n/cm, 4.8 x 101 8n/cm 2.and 7.5 x T018n/cm, respectively. Based on the neutron fluence estimated by the licensee for each beltline material and the uncertainty in vessel dosimetry identified.by B&W*, we conclude that the USE energy at the 1/4 thickness location for the Oconee beltline reactor vessel materials will excied50 ft-lbs for the period of time that the proposed pressure-temperature curves are applicable.
Using the method for predicting shift in RT NT in Regulatory Guide 1.99, Rev. 1, the neutron fluence estimates of the.icensee, the unirradiated material properties in B&W Reports BAW-1511P, October 1980, and BAW-10046P, March 1976, and the method of calculating pressure-temperature limits identified in Standard Review Plan Section 5.3.2, the proposed pressure-temperature limit curves for Oconee Units 1, 2 and 3 meet the safety margins of Appendix G,. 10 CFR Part 50, and are acceptable for 15 EFPY.
- C.. Whitmarsh, Draft B&W Report to be Published.
Table 1 Comparison of Change in Properties for OC III-B and OC II-A Capsule.Weld Materials Change in RTNDT (0F)
Change in USE (Percentage)
Capsule Req. 1.99 BAW-1511P Capsule Reg. 1.99 BAW-1511P WF 209-1B 89 170 N/A 24 34 24.5 WF-209-1A 104 226 N/A 28 36 27 Estimated per Figure 3, page C-10 of B&W Report BAW-1511P, October 1980.
DPC 3
Environmental Consideration We have determined that the amendments do not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact. Having made this determination, we have further concluded that the amendments involve an action which is insignificant from the standpoint of environmental impact and, pursuant to 10 CFR 551.5(d)(4), that an environmental impact statement, or negative declaration and environ mental impact appraisal need not be prepared in connection with the issuance of these amendments.
Conclusion We have concluded, based on the considerations discussed above, that:
(1) because the amendments do not involve a significant increase in the probability or consequences of an accident previously evaluated, do not create the possibility of an accident of a type different from any evaluated previously, and do not involve a significant reduction in a margin of safety, the amendments do not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public Dated:
MAR 11 1983 The following NRC personnel have contributed to this Safety Evaluation:
L. Lois, B. Elliot, E. Conner.
lop.
47I
.-._ 7777