ML092570665

Request for Additional Information Related to Generic Letter 2008-01, Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems

ML092570665
Person / Time
Site:	LaSalle
Issue date:	09/21/2009
From:	Goodwin C Plant Licensing Branch III
To:	Pardee C Exelon Generation Co, Exelon Nuclear
Goodwin, Cameron S, NRR/DORL, 415-3719
References
GL-08-001, TAC MD7839, TAC MD7840
Download: ML092570665 (4)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 September 21,2009 Mr. Charles G. Pardee President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

LASALLE COUNTY STATION, UNITS 1 AND 2 - REQUEST FOR ADDITIONAL INFORMATION RELATED TO GENERIC LETTER 2008-01, "MANAGING GAS ACCUMULATION IN EMERGENCY CORE COOLING, DECAY HEAT REMOVAL, AND CONTAINMENT SPRAY SYSTEMS" (TAC NOS. MD7839 AND MD7840)

Dear Mr. Pardee:

By letter to the Nuclear Regulatory Commission (NRC) dated October 14, 2008 (Agencywide Documents Access and Management System Accession No. ML082880706), Exelon Generation Company, LLC, submitted its 9-month response to Generic Letter 2008-01, for the LaSalle County Station, Units 1 and 2.

The NRC staff is reviewing your submittal and has determined that additional information is required to complete the review. The specific information requested is addressed in the enclosure to this letter. During a discussion with your staff on September 10, 2009, it was agreed that you would provide a response within 45 days from the date of this letter.

The NRC staff considers that timely responses to requests for additional information help ensure sufficient time is available for staff review and contribute toward the NRC's goal of efficient and effective use of staff resources. If circumstances result in the need to revise the requested response date, please contact me at (301) 415-3719.

Sincerely,

~rd~~

Cameron S. Goodwin, Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-373 and 50-374

Enclosure:

Request for Additional Information cc w/encl: Distribution via ListServ

REQUEST FOR ADDITIONAL INFORMATION LASALLE COUNTY STATION (LSCS), UNITS 1 AND 2 DOCKET NOS. 50-373 AND 50-374 Guidance on the Nuclear Regulatory Commission (NRC) staff expectations is provided by Reference 1 which is generally consistent with Nuclear Energy Institute (NEI) guidance provided to industry in Reference 2 as clarified in later NEI communications. The NRC staff recommends that the licensee consult Reference 1 when responding to the following requests for additional information:

1. LSCS determined that the following systems are within the scope of Generic Letter (GL) 2008-01 :

• High Pressure Core Spray

• Low Pressure Core Spray

• Residual Heat Removal (RHR) (Suppression Pool Cooling, Low Pressure Coolant Injection, Shutdown Cooling, Drywell Spray, and Suppression Pool Spray modes of RHR).

The Reference 3 document states the above systems were evaluated with respect to the current licensing and design bases; however, it is unclear if the licensee evaluated these systems for gas intrusion under all modes of operation. Please clarify what mode or modes the above systems were evaluated.

2. The mention of systems that perform a "keep-full" function is not present in LaSalle's submittal, and is addressed in the GL as used to maintain systems full of water. Please either identify keep-full system(s) as part of the scope of the GL or justify the exclusion.

3. The technical specification verification of emergency core cooling system piping is "from the pump discharge valve to the injection valve every 31 days." Suction piping is not addressed. Please justify how the current surveillance reasonably ensures the systems are and will remain operable and explain the process to determine if the frequency of surveillance needs to be changed.

4. Provide a broad identification of surveillance locations and methods with identification and justification of excluded locations. Also, confirm if all high points are equipped with vents; and if not, justify why the location does not need vents.

5. It is stated that "the impact of the voids on system operability is evaluated on a case-by case basis, with acceptable void volumes being determined as part of the evaluation."

Describe the void volume determination methods and the actions that will be taken if void volume criteria are not met. The term "acceptable void volume" is unclear, please explain.

-2

6. What industry guidance is being used in the void volume evaluation process?

7. Address the process of determining when confirmatory ultrasonic testing (UT) examinations are required as part of system restoration.

8. Explain Exelon Generation Company plans to implement a graded approach for performing periodic UT examinations. The term "graded approach" is unclear.

9. Are all gas intrusion/accumulation discoveries entered in the corrective action program?

If not, please justify.

10. Identify any supplementary actions to address control of voids in the subject systems that are not covered by TS requirements and the process that reasonably ensures the supplementary actions will be accomplished.

11. Training was not identified in the GL, but is considered to be a necessary part of applying procedures and other activities when addressing the issues identified in the GL. Briefly discuss training.

REFERENCES

1. Ruland, William H., "Preliminary Assessment of Responses to Generic Letter 2008-01,

'Managing Gas Accumulation in emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems,' and Future NRC Staff Review Plans," NRC letter to James H. Riley, Nuclear Energy Institute, ML091390637, May 28,2009.

2. Riley, James H., "Generic Letter (GL) 2008-01, 'Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Contain Spray Systems' Evaluation and 3 Month Response Template," Letter to Administrative Points of Contact from Director, Engineering, Nuclear Generation Division, Nuclear Energy Institute, Enclosure 2, "Generic Letter 2008-01 Response Guidance," March 20, 2008.

3. K. R. Jury, "LaSalle County Station (LSCS) Units 1 and 2 - Nine-Month Response to Generic Letter 2008-01," Vice President - Licensing and Regulatory Affairs Exelon Generation Company, LLC, AmerGen Energy Company, LLC, October 14,2008.

ML092570665 NRR-088 OFFICE LPL3-2/PM LPL3-2/LA LPL3-2/BC NAME CGoodwin THarris SCampbell DATE 09/18/09 09/18/09 09/21/09