ML023570268
| ML023570268 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 04/16/2002 |
| From: | Merrifield J NRC/OCM |
| To: | |
| References | |
| CORR-02-0076 | |
| Download: ML023570268 (3) | |
Text
A -0 30.3 CORR: 02-0076 CORR: 02-0076 COMMISSION CORRESPONDENCE Correspondence Response Sheet Date: April 15,2002 coýcý.,
To: Chairman Meserve CommissionerDicus CommissionerDiaz CommissionerMcGaffigan CommissionerMerrifieid.-X From: Annette Vietti-Cook, Secretary I
Subject:
Letter to Congresswoman Marcy Kaptur, concerns recent
-discoveryof a cavity in the reactorpressure vessel head at Davis-Besse ACTION: Please comment/concur and respond to the Office of the Secretaryby.
Time: 4:00 P.M.
Day: Wednesday Date: April 17,2002 Comment: COMMENTS REQUESTED NLT WEDNESDAY, APRIL 17,2002
Contact:
Stephen Sands, NRR/EDO 415-3154 Enteredin STARS Tracking System *es []No NRR- 1,o4
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 CHAIRMAN The Honorable Marcy Kaptur United States House of Representatives Washington, D.C. 20515 Dear CongresswomanKauLl . - .
I am responding to your letter of March 28, 2002, concerning the recent discovery of a cavity in the reactor pressure vessel (RPV) head at the Davis-Besse Nuclear Power Station (DBNPS).
On March 12, 2002, the Nuclear Regulatory Commission D issued a confirmatory X action letter (CAL) to Davis-Besse as a result of the discovery of degradation in the pressure boundary material of the RPV. The CAL requires the licensee to obtain prior NRC approval of any repairs, modifications and testing.of the RPV head. The NRC staff will review any proposed repairs to the reactor vessel head and ensure they meet all applicable regulatory requirements for assuring structural integrity. In general, NRC requirements endorse the requirements set forth in the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code. In addition, any other modification that results from the repair of the vessel head must fully meet all NRC regulations. NRC fully understands the significance of this degradation and is allocating substantial technical resources to reviewing the licensee's proposed repair. The review will focus on whether the repair can withstand the environment of an operating reactor.
On learning of the cavity, NRC sent an augmented inspection team (AIT) to Davis Besse to identify the facts and circumstances surrounding the formation and discovery of the cavity in the RPV head. This team was comprised of senior level NRC technical staff and
M. Kaptur -2 gathered important factual information on the degradation and the licensee's actions related to it. The AIT has completed its review and presented its findings at a public meeting with the Davis-Besse licensee on April 5, 2002. The final AIT report will be posted on the NRC Web site (www.nrc.gov) when it is completed.
Now that the AIT has completed its fact-finding mission at Davis-Besse, the NRC will do an in-depth technical review that will focus on the data arising from the AIT report, the licensee's RPV visual inspections, root cause analysis, nondestructive examinations, and proposed corrective actions. The facts and circumstances of the event will comprise a majority of the information included in the NRC's AIT report. This information, coupled with the licensee's root cause evaluations (which will be reviewed by the NRC), should provide a complete accounting of the event and the licensee's response. If, after review of our report and the licensee's evaluation, you and other elected officials believe that a site visit would be beneficial, we would be glad to work with you and the licensee to effect such a visit.
NRC held a public meeting with industry representatives on March 19, 2002, and another on March 20, 2002, with external stakeholders to provide up-to-date information on RPV head corrosion. NRC also issued two information notices (IN-2002-11 & 13) and a bulletin (BL-2002-01) to holders of operating licenses for pressurized-water power reactors. The bulletin requires the addressees to submit information on their inspections of the integrity of the RPV boundary. NRC also held a public meeting to discuss Davis-Besse's proposed repairs and modifications to the reactor vessel head on April 10, 2002, in Rockville, Maryland.
.4-assure you that, based on the findings of the AIT and NRC's review, the Commission will take appropriate actions to ensure that Davis-Besse maintains adequate safety margins. -t"