L-PI-06-101, Supplemental Response to Generic Letter 2003-01, Control Room Habitability.

Supplemental Response to Generic Letter 2003-01, Control Room Habitability.

ML063520545
Person / Time
Site:	Prairie Island
Issue date:	12/18/2006
From:	Thomas J. Palmisano Nuclear Management Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
GL-03-001, L-PI-06-101, RG-1.078
Download: ML063520545 (4)

Text

Prairie Island Nuclear Generating Plant Operated by Nuclear Management Company, LLC December 18, 2006 L-PI-06-101 Generic Letter 2003-01 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 PRAIRIE ISLAND NUCLEAR GENERATING PLANT DOCKET NOS. 50-282 AND 50-306 LICENSE NOS. DPR-42 AND DPR-60 SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2003-01, CONTROL ROOM HABITABILITY

References:

1) Letter from U.S. NRC to addressees, NRC Generic Letter 2003-01:

Control Room Habitability, dated August 11, 2003.

2) Letter from NMC to Document Control Desk, Response to Generic Letter 2003-01, Control Room Habitability.

3) U.S. NRC Regulatory Guide 1.78, Evaluating the Habitability of a Nuclear Power Plant Control Room during a Postulated Hazardous Chemical Release.

On June 12, 2003, the Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2003-01, Control Room Habitability (Reference 1). Nuclear Management Company, LLC (NMC), submitted the required information for Prairie Island Nuclear Generating Plants (PINGP) Units 1 and 2 within 180 days as requested by NMC letter (LI-PI-03-114) dated December 9, 2003 (Reference 2).

In an email dated November 1, 2006, the NRC requested additional information to complete the review of the PINGP Response to Generic Letter 2003-01. to this letter provides the supplemental information requested by the NRC staff.

1717 Wakonade Drive East

• Welch, Minnesota 55089-9642 Telephone: 651.388.1121

Document Control Desk Page 2 Summarv of Commitments This letter contains no new commitments and no revisions to existing commitments.

~ h o m a sJ. Palmisano Site Vice President, Prairie Island Nuclear Generating Plant Nuclear Management Company, LLC Enclosure (1) cc: Administrator, Region Ill, USNRC Project Manager, Prairie Island, USNRC Senior Resident Inspector, Prairie Island, USNRC

ENCLOSURE I GENERIC LETTER 2003-01-SUPPLEMENTAL RESPONSE PRAIRIE ISLAND NUCLEAR GENERATING PLANT UNITS 1 AND 2 NRC QUESTIONS:

"We would like the licensee to confirm the following:

1. That the survey of off site chemicals they committed to perform by July 2004 in their response to GL 2003-01 was completed and that the survey did not change their previous response to the GL. (No credit is taken for control room design in limiting the effects of a toxic chemical release, therefore, unfiltered in-leakage is not considered in the toxic chemical analyses)

2. That the tracer gas testing they committed to perform in 2004 in their response to GL 2003-01 was completed and that it did not change their previous response to the GL. We are looking for confirmation that the maximum tested value for unfiltered in-leakage into the control room envelope determined from the 2004 test is no more than the value assumed in their design basis radiological analyses for control room habitability.

NMC RESPONSE TO QUESTION 1:

Via Reference 2, NMC committed to the performance of an offsite chemical survey at Prairie Island Nuclear Generating Plant (PINGP) by July 2004. The offsite survey was performed and approved on July 23,2004. The objective of this survey was to identify any hazardous materials stored or shipped near the PINGP that had not been previously analyzed, determine if any additional evaluations need to be performed, and perform those evaluations. Following the initial survey of offsite chemicals, 10 additional chemicals were identified as requiring further evaluation. The evaluations of the additional chemicals were performed in accordance with the guidance in Regulatory Guide (RG) 1.78 (Reference 3). The calculations evaluated the release of chemicals with the conservative assumption that the Control Room Ventilation System would, at no time, be placed in a mode where the outside air intake would be reduced.

Following the performance of the survey and the vendor calculation, NMC concluded that there were no offsite chemicals that pose a threat to the PINGP control operators.

The PINGP chemical survey report has been determined to be withheld from public disclosure under 10 CFR 2.390; and as such is not included as part of this response.

Page 1 of 2

ENCLOSURE 1 GENERIC LETTER 2003-01-SUPPLEMENTAL RESPONSE PRAIRIE ISLAND NUCLEAR GENERATING PLANT UNITS 1 AND 2 NMC RESPONSE TO QUESTION 2:

Via Reference 2, NMC committed to the performance of Control Room (CR) tracer gas testing at Prairie Island Nuclear Generating Plant (PINGP) in 2004.

The tracer gas testing was performed during the week of November 29 through December 3, 2004. The objective of this test was to validate the CR unfiltered in-leakage assumptions used to develop the expected post-accident radiological doses to the CR staff.

Previous CR tracer gas testing results, obtained during the I998 test, were submitted in Reference 2.

The results of the 2004 test and a comparison to the 1998 results are provided below:

System Configuration July 1998 Results 2004 Results Unfiltered In-leakage Unfiltered In-leakage (cfm) (cfm)

High Radiation-Train A(') 160k5 115&36 Safety Injection-Train A(') 145k5 114k21 (1) In-leakage results are higher with Train A operating.

As discussed in Reference 2, the July 1998 results were less than the values used in the radiological analyses. Subsequent to the response in Reference 2, new radiological analyses have been performed for the Fuel Handling Accident (FHA). For the FHA analysis, the assumed values for CR unfiltered in-leakage are: 400 cfm for boundary in-leakage plus 10 cfm for ingress and egress for a total value of 410 cfm. As shown in the above table, the values from the 2004 testing are less than the results from the July 1998 testing. Therefore, based on the results depicted above, that the PINGP CR unfiltered in-leakage values do not exceed the assumed values in the current radiological analysis for Control Room Habitability.

Page 2 of 2

Text

Prairie Island Nuclear Generating Plant Operated by Nuclear Management Company, LLC December 18, 2006 L-PI-06-101 Generic Letter 2003-01 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 PRAIRIE ISLAND NUCLEAR GENERATING PLANT DOCKET NOS. 50-282 AND 50-306 LICENSE NOS. DPR-42 AND DPR-60 SUPPLEMENTAL RESPONSE TO GENERIC LETTER 2003-01, CONTROL ROOM HABITABILITY

References:

1) Letter from U.S. NRC to addressees, NRC Generic Letter 2003-01:

Control Room Habitability, dated August 11, 2003.

2) Letter from NMC to Document Control Desk, Response to Generic Letter 2003-01, Control Room Habitability.

3) U.S. NRC Regulatory Guide 1.78, Evaluating the Habitability of a Nuclear Power Plant Control Room during a Postulated Hazardous Chemical Release.

On June 12, 2003, the Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2003-01, Control Room Habitability (Reference 1). Nuclear Management Company, LLC (NMC), submitted the required information for Prairie Island Nuclear Generating Plants (PINGP) Units 1 and 2 within 180 days as requested by NMC letter (LI-PI-03-114) dated December 9, 2003 (Reference 2).

In an email dated November 1, 2006, the NRC requested additional information to complete the review of the PINGP Response to Generic Letter 2003-01. to this letter provides the supplemental information requested by the NRC staff.

1717 Wakonade Drive East

• Welch, Minnesota 55089-9642 Telephone: 651.388.1121

Document Control Desk Page 2 Summarv of Commitments This letter contains no new commitments and no revisions to existing commitments.

~ h o m a sJ. Palmisano Site Vice President, Prairie Island Nuclear Generating Plant Nuclear Management Company, LLC Enclosure (1) cc: Administrator, Region Ill, USNRC Project Manager, Prairie Island, USNRC Senior Resident Inspector, Prairie Island, USNRC

ENCLOSURE I GENERIC LETTER 2003-01-SUPPLEMENTAL RESPONSE PRAIRIE ISLAND NUCLEAR GENERATING PLANT UNITS 1 AND 2 NRC QUESTIONS:

"We would like the licensee to confirm the following:

1. That the survey of off site chemicals they committed to perform by July 2004 in their response to GL 2003-01 was completed and that the survey did not change their previous response to the GL. (No credit is taken for control room design in limiting the effects of a toxic chemical release, therefore, unfiltered in-leakage is not considered in the toxic chemical analyses)

2. That the tracer gas testing they committed to perform in 2004 in their response to GL 2003-01 was completed and that it did not change their previous response to the GL. We are looking for confirmation that the maximum tested value for unfiltered in-leakage into the control room envelope determined from the 2004 test is no more than the value assumed in their design basis radiological analyses for control room habitability.

NMC RESPONSE TO QUESTION 1:

Via Reference 2, NMC committed to the performance of an offsite chemical survey at Prairie Island Nuclear Generating Plant (PINGP) by July 2004. The offsite survey was performed and approved on July 23,2004. The objective of this survey was to identify any hazardous materials stored or shipped near the PINGP that had not been previously analyzed, determine if any additional evaluations need to be performed, and perform those evaluations. Following the initial survey of offsite chemicals, 10 additional chemicals were identified as requiring further evaluation. The evaluations of the additional chemicals were performed in accordance with the guidance in Regulatory Guide (RG) 1.78 (Reference 3). The calculations evaluated the release of chemicals with the conservative assumption that the Control Room Ventilation System would, at no time, be placed in a mode where the outside air intake would be reduced.

Following the performance of the survey and the vendor calculation, NMC concluded that there were no offsite chemicals that pose a threat to the PINGP control operators.

The PINGP chemical survey report has been determined to be withheld from public disclosure under 10 CFR 2.390; and as such is not included as part of this response.

Page 1 of 2

ENCLOSURE 1 GENERIC LETTER 2003-01-SUPPLEMENTAL RESPONSE PRAIRIE ISLAND NUCLEAR GENERATING PLANT UNITS 1 AND 2 NMC RESPONSE TO QUESTION 2:

Via Reference 2, NMC committed to the performance of Control Room (CR) tracer gas testing at Prairie Island Nuclear Generating Plant (PINGP) in 2004.

The tracer gas testing was performed during the week of November 29 through December 3, 2004. The objective of this test was to validate the CR unfiltered in-leakage assumptions used to develop the expected post-accident radiological doses to the CR staff.

Previous CR tracer gas testing results, obtained during the I998 test, were submitted in Reference 2.

The results of the 2004 test and a comparison to the 1998 results are provided below:

System Configuration July 1998 Results 2004 Results Unfiltered In-leakage Unfiltered In-leakage (cfm) (cfm)

High Radiation-Train A(') 160k5 115&36 Safety Injection-Train A(') 145k5 114k21 (1) In-leakage results are higher with Train A operating.

As discussed in Reference 2, the July 1998 results were less than the values used in the radiological analyses. Subsequent to the response in Reference 2, new radiological analyses have been performed for the Fuel Handling Accident (FHA). For the FHA analysis, the assumed values for CR unfiltered in-leakage are: 400 cfm for boundary in-leakage plus 10 cfm for ingress and egress for a total value of 410 cfm. As shown in the above table, the values from the 2004 testing are less than the results from the July 1998 testing. Therefore, based on the results depicted above, that the PINGP CR unfiltered in-leakage values do not exceed the assumed values in the current radiological analysis for Control Room Habitability.

Page 2 of 2