DCL-10-014, Supplement to Nine Month Response to NRC Generic Letter 2008-01, Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems
| ML100430827 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 02/09/2010 |
| From: | Becker J Pacific Gas & Electric Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| DCL-10-014, GL-08-001 | |
| Download: ML100430827 (2) | |
Text
Pacific Gas and Electric Company February g, 2010 PG&E letter DCl-1 0-014 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852 Docket No. 50-323, Ol-DPR-82 Diablo Canyon Unit 2 James R. Becker Site Vice President Diablo Canyon Power Plant Mail Code 104/5/601
- p. O. Box 56 Avila Beach, CA 93424 805.545.3462 Internal: 691.3462 Fax: 805.545.6445 10 CFR 50.54(f)
Supplement to Nine Month Response to NRC Generic letter 2008-01. "Managing Gas Accumulation in Emergency Core Cooling. Decay Heat Removal, and Containment Spray Systems"
References:
- 1.
NRC Generic letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems," dated January 11, 2008
- 2.
PG&E letter DCl-08-090, "Nine-Month Response to NRC Generic letter 2008-01, 'Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems,'" dated October 14,2008 The U. S. Nuclear Regulatory Commission (NRC) issued NRC Generic letter (Gl) 2008-01 (Reference 1) to request that each licensee evaluate its emergency core cooling system, residual heat removal system, and containment spray system licensing basis, design, testing, and corrective actions to ensure that gas accumulation is maintained less than the amount that challenges operability of these systems, and that appropriate action is taken when conditions adverse to quality are identified.
In Reference 2, Pacific Gas and Electric Company (PG&E) made the following regulatory commitment:
During the piping isometric drawing reviews performed in August 2008, PG&E identified a long horizontal section of the residual heat removal pump (RHRP) discharge piping inside containment that exceeds the piping walkdown screening criteria of 14 times the pipe diameter.
There is an existing vent in this section of the RHRP discharge piping.
PG&E will perform a confirmatory walkdown to verify as-built piping configuration for this section of the RHRP discharge piping. PG&E will A
member of the STARS (Strategic Teaming and Resource Sharing)
Alliance Callaway Comanche Peak. Diablo Canyon. Palo Verde
- San Onofre. South Texas Project. Wolf Creek
Docu ment Control Desk February 9, 2010 Page 2 PG&E Letter DCL-1 0-014 complete its assessments of this section of piping during Unit 2 refueling outage fifteen (2R 15), and provide a supplement to this report with those results within 90 days from completion of that outage.
PG&E completed DCPP 2R15 on November 10, 2009. During the Unit 2 walkdowns, PG&E identified a high point on the RHRP line. PG&E verified that there was no gas accumulation following the RHRP dynamic flush coming out of the 2R15.
PG&E is making the following new regulatory commitment: PG&E will install a vent at this high point on the RHRP line during Unit 2 refueling outage sixteen (2R16).
This response is submitted in accordance with 10 CFR 50.4.
If there are any questions or if additional information is needed, please contact Tom Baldwin at 805-545-4720.
I state under penalty of perjury that the foregoing is true and correct.
Executed on February 9,2010.
mjrm/4557/50037662 cc:
Alan B. Wang, Project Manager, Office of Nuclear Reactor Regulation Gary W. Butner, California Department of Public Health Elmo E. Collins, NRC Region IV Michael S. Peck, NRC, Senior Resident Inspector Diablo Distribution A
member of the STARS (Strategic Teaming and Resource Sharing)
Alliance Calla w ay
- Comanche Peak
- Diablo Canyon
- Palo Verde
- San Onofre
- South Te xas Project
- Wolf Creek