ML021490085
| ML021490085 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 05/29/2002 |
| From: | Chandu Patel NRC/NRR/DLPM/LPD2 |
| To: | John Nakoski NRC/NRR/DLPM/LPD2 |
| Patel C P, NRR/DLPM, 415-3025 | |
| References | |
| BL-02-001, TAC MB4535, TAC MB4536 | |
| Download: ML021490085 (3) | |
Text
May 29, 2002 MEMORANDUM TO:
John A. Nakoski, Chief, Section 1 Project Directorate II Division of Licensing Project Management FROM:
Chandu P. Patel, Project Manager, Section 1 /RA/
Project Directorate II Division of Licensing Project Management
SUBJECT:
SUMMARY
OF TELEPHONE CONFERENCE ON MAY 20, 2002, WITH DUKE ENERGY CORPORATION RE: RESPONSE TO BULLETIN 2002-01, CATAWBA NUCLEAR STATION, UNITS 1 AND 2 (TAC NOS. MB4535 AND MB4536)
On May 20, 2002, the U.S. Nuclear Regulatory Commission (NRC) staff held a telephone conference with representatives of Duke Energy Corporation (licensee) regarding the information in its April 1, 2002, response (15-day response) to NRC Bulletin 2002-01, Reactor Pressure Vessel Head Degradation and Reactor Coolant Pressure Boundary Integrity, dated March 18, 2002. The following questions on the Catawba Units 1 and 2 15-day response were provided by e-mail to the licensee and discussed during the telephone conference.
Staff Questions on Catawba Units 1 and 2 Q.1 Your 15-day response to Bulletin 2002-01 documents past leakage due to conoseals, and in the case of Catawba Unit 2, a control rod drive mechanism vent line plug. Clarify whether there was any evidence that the leakage reached the reactor pressure vessel (RPV) head insulation.
Licensee Response Yes, there is evidence that some past leaks on both units did reach the head insulation.
Q.2 For leakage that may have reached the insulation, discuss the inspections that were performed at these locations (i.e., were the partial head inspections that are mentioned in the 15 day Bulletin response performed in these regions).
Licensee Response Inspections were limited to the top of the insulation and the components above the insulation. No inspection of the head itself was performed. The licensee performed a partial head inspection during the removal of an upper head injection penetration, but the inspection was not in response to any boric acid leakage.
Q.3 For each leakage event, quantify the amounts of boric acid deposits that were on the insulation and the basis for assuming that no boric acid reached the head in those regions.
Licensee Response The licensee stated that it is impossible to quantify specifically (i.e., number of grams) on an event-specific basis. Some early cycle leaks occurred prior to the initiation of the work management system and problem identification process programs. All leaks were repaired, and the boric acid was removed from the top of the insulation and all components above the insulation at the time of discovery of the leaks. There is no basis for assuming that no boric acid reached the head. There is the possibility that some acid did reach the head; however, it would have immediately dried from the elevated temperature on top of the RPV head. Also there would have been no constant source of moisture to lead to corrosion of the head.
The staff indicated to the licensee that it was looking for a qualitative assessment of the leakage rather than quantitative assessment.
Q.4 Clarify whether or not all leaks were repaired during the outage in which they were detected.
Licensee Response All leaks were repaired during the outage in which they were detected.
The licensee agreed to provide the above clarifications within 30 days from the date of the phone call.
Docket Nos. 50-413 and 50-414 Licensee Response The licensee stated that it is impossible to quantify specifically (i.e., number of grams) on an event-specific basis. Some early cycle leaks occurred prior to the initiation of the work management system and problem identification process programs. All leaks were repaired, and the boric acid was removed from the top of the insulation and all components above the insulation at the time of discovery of the leaks. There is no basis for assuming that no boric acid reached the head. There is the possibility that some acid did reach the head; however, it would have immediately dried from the elevated temperature on top of the RPV head. Also there would have been no constant source of moisture to lead to corrosion of the head.
The staff indicated to the licensee that it was looking for a qualitative assessment of the leakage rather than quantitative assessment.
Q.4 Clarify whether or not all leaks were repaired during the outage in which they were detected.
Licensee Response All leaks were repaired during the outage in which they were detected.
The licensee agreed to provide the above clarifications within 30 days from the date of the phone call.
Docket Nos. 50-413 and 50-414 DISTRIBUTION:
PUBLIC PD II-1 R/F EMCB R/F HBerkow WBateman JNakoski ALee, EMCB SBloom, LPM RHaag, R-II CHawes OGC ACRS ACCESSION NO. ML021490085
- See previous concurrence OFFICE PDII-1/PM EMCB/LPM*
PDII-1/LA PDII-1/SC NAME CPatel SBloom CHawes JNakoski DATE 05/24/02 05/24/02 05/24/02 05/24/02 OFFICIAL RECORD COPY