ML20113H610
| ML20113H610 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 07/30/1992 |
| From: | Link B WISCONSIN ELECTRIC POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| CON-NRC-92-088, CON-NRC-92-88, RTR-REGGD-01.099, RTR-REGGD-1.099 GL-92-01, GL-92-1, VPNPD-92-274, NUDOCS 9208050085 | |
| Download: ML20113H610 (2) | |
Text
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.s Wisconsin
! Electnc POWER COMPANY 231 w Mencan. Po bm 204wwwo w 53?oi Muj2a2ns VPNPD-92-274 NPC-92-088 July 30, 1992 U.
S.
NUCLEAR REGULATORY COMMISSION Document Control Desk Mail Station P1-137 Washington, DC 20555 Gentlemen:
DOCKETS 50-266 AND 50-301 SUPPLEMENTAL RESPONSE TO REQ _ GENERIC LETTER 92-01. REVISION 1 REACTOR VESGEL STRUCTURAL. INTEGRITY, 10 CFR 50.54(f)
POINT BEACil NUCLEAR PLANT. UNITS 1 AN U NRC Generic Letter 92-01, " Reactor Vessel Structural Integrity,"
was issued to obtain information from licensees to enable the NRC to assess compliance with regulatory requirements and commitments regarding reactor vessel integrity.
Wisconsin Electric provided our response to this Generic Letter on June 25, 1992.
Included as a supporting document to our response was BAW-2166, "B&W Owners Group Response to Generic Letter 92-01."
This letter is transmitted to provide additional information to supplement our initial response to two of the information items requested in Generic Letter 92-01.
Generic Letter 92-01, Section 2, Item b, Subitem 5, requested that tne chemical composition for each beltline and surveillance material be provided.
In Table 7 of BAW-2166 for Point Beach Nuclear Plant, Unit 1, it was stated that the nickel content of the plate material was considered suspect and that verification of this information is planned.
We have since been able to verify this information through Westinghouse and B&W Nuclear Service Company documents and consider the information provided in Table 7 of BAW-2166 to be accurate for Point Beach Nuclear Plant, Unit 1.
Section 3, Item a, of Generic Letter 92-01 requested information regarding how the embrittlement effects of operating at a temperature below 525*F were considered for Charpy upper shelf energy and reference temperature.
In our original response, we reported that Point Beach, Unit 1 had operated at reduced power 9208050005 920730 PDR ADOCK 050002,66 P
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. Docket ControlcDesk July 30,'1992 Page 2 the end of fuel cycles.
During these coastdown periods, primary system temperature is_ lowered to take advantage of the resulting reactivity addition to prolong the life of the core.
During five coastdown periods for each unit, the cold leg
. temperature of the associated unit dropped below 525"F.
The cumulative operation time-below 525'F is approximately 94 days for Unit 1 and 37 days for Unit 2.
.The minimum temperature
-experienced during any of the coastdowns was 509'F for Unit 1 and 515'F for Unit 2.
The accumulated fluence on the reactor vesselt:
that each unit _ received while operating below 525*F for the 2
2 coastdown periods was 1.96E+17 n/cm for Unit 1 and 9.49E+16 n/cm for Unit 2.
These fluence values are less than one percent of the maximum fluence the vessels are expected to receive during their design life.. Additionally, the surveillance capsules removed to date from each unit have shown that the surveillance material behavior is conservatively estimated by Regulatory Guide 1.99, Revision-2.
Therefore, these periods of low-temperature operation were not considered in the determination of embrittlement effects.
We believe that our response to Generic Letter 92-01 and this supplement have demonstrated our continued compliance with 10 CFR 50.60 and conformance to our commitments made in response to Generic Letter.88-11.
Please contact us should you have questions or require additional information regarding this or our previous response.
l
. Sincerely, j
Bob Link Vice President Nuclear Power ~
I Copies to NRC Regional-Administrator, Region III NRC Resident Inspector l