ML16015A001

[External_Sender] Oyster Creek FHRR Clarification Question 1.a Response

ML16015A001
Person / Time
Site:	Oyster Creek
Issue date:	01/14/2016
From:	Distel D J Exelon Corp
To:	Govan T V Japan Lessons-Learned Division
References
Download: ML16015A001 (3)

Text

1 NRR-PMDAPEm Resource From: Distel, David J:(GenCo-Nuc) <David.Distel@exeloncorp.com>

Sent: Thursday, January 14, 2016 10:49 AM To: Govan, Tekia Cc:Joe Bellini; Samlal, Valmicky:(GenCo-Nuc)

Subject:

[External_Sender] Oyster Creek FHRR Clarification Question 1.a ResponseTekia - The following information provides the response for NRC clarification Question 1.a, as discussed in today's follow-up conference call.

Follow-up Response to Question 1a of the Oyster Creek FHRR Audit Information Request

In Question 1a of the Oyster Creek FHRR Audit Information Request, the NRC sought clarification as to whether structures at the northeast corner of the Reactor Building would permit the conveyance of LIP-generated surface water runoff along the east face of the Reactor Building. Exelon clarified that the area at the northeast corner of the Reactor Building and along the east side of the Reactor Building (between the Reactor Building and the Old Rad Waste Building) is obstructed to flow. The NRC agreed with this clarification but did not agree that the FLO-2D model (updated to replace Area Reduction Factors with raised ground elements to more conservatively account for roof runoff) represented this obstruction. Exelon reviewed the updated model and concur that, when Area Reductions Factors were removed, a gap was inadvertently created between the Reactor Building and Old Radwaste Building, which is occupied by the Drywell Processing Center. The FLO-2D model was corrected to fill this gap with a raise ground element and prevent flow from passing between the buildings, which resulted in a flooding depth of 0.87 foot above the door sill (a 0.36 foot increase) at Door 9. The increase appear s to be the same as the NRC's sensitivity analysis described in the follow-up question. The flooding duration also increased by 0.58 hour6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br />. The table below presents the corrected results for each door location. Exelon is currently preparing an updated LIP calculation to incorporate the correction.

Door No. Reference Grid Element No. Max. Water Surface Station Grade/ Door Sill Elevation Max. Flooding Depth Above the Station Grade/Door Sill Elevation Flooding Duration Above the Station Grade/Door Sill Elevation ft. (NAVD

88) ft. (MSL) Ft (MSL) ft. hrs. Door 1 24458 22.70 22.72 23.50 -0.78 0.00 Door 2 26887 22.75 22.77 23.50 -0.73 0.00 Door 3 23275 22.70 22.72 23.50 -0.78 0.00 Door 4 26895 23.16 23.18 23.50 -0.32 0.00 Door 5 22982 22.70 22.72 23.50 -0.78 0.00 Door 6 27829 23.02 23.04 23.50 -0.46 0.00 Door 7 30020 23.07 23.09 23.50 -0.41 0.00 Door 8 31919 23.20 23.22 23.50 -0.28 0.00 Door 9 26009 24.35 24.37 23.50 0.87 1.52 Door 10 20654 22.62 22.64 23.62 -0.98 0.00 Door 11 20647 22.82 22.84 23.61 -0.77 0.00 2Door 12 19802 23.57 23.59 23.60 -0.01 0.00 Door 13 18978 23.63 23.65 23.69 -0.04 0.00

Please let me know if any additional information is needed.

Thanks.

Dave Distel

This Email message and any attachment may contain information that is proprietary, legally privileged, confidential and/or subject to copyright belonging to Exelon Corporation or its affiliates ("Exelon"). This Email is intended solely for the use of the person(s) to which it is addressed. If you are not an intended recipient, or the employee or agent responsible for delivery of this Ema il to the intended recipien t(s), you are hereby notified that any dissemination, distribution or copying of this Email is strictly prohibited. If you have received this message in error, please immediately notify the sender and permanently delete th is Email and any copies.

Exelon policies expressly prohibit employees from making defamatory or offensive statements and infringing any copyright or any other legal right by Email communication. Exelon will not accept any liability in respect of such communications. -EXCIP Hearing Identifier: NRR_PMDA Email Number: 2594 Mail Envelope Properties (4BCCAD574B0D614096E6221C12ED97D876AD974B)

Subject:

[External_Sender] Oyster Creek FHRR Clarification Question 1.a Response Sent Date: 1/14/2016 10:49:13 AM Received Date: 1/14/2016 10:49:19 AM From: Distel, David J:(GenCo-Nuc)

Created By: David.Distel@exeloncorp.com Recipients: "Joe Bellini" <joe.bellini@aterrasolutions.com>

Tracking Status: None "Samlal, Valmicky:(GenCo-Nuc)" <Valmicky.Samlal@exeloncorp.com> Tracking Status: None "Govan, Tekia" <Tekia.Govan@nrc.gov> Tracking Status: None

Post Office: exchm-omf-24.exelonds.com Files Size Date & Time MESSAGE 3893 1/14/2016 10:49:19 AM Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: Recipients Received:

1 NRR-PMDAPEm Resource From: Distel, David J:(GenCo-Nuc) <David.Distel@exeloncorp.com>

Sent: Thursday, January 14, 2016 10:49 AM To: Govan, Tekia Cc:Joe Bellini; Samlal, Valmicky:(GenCo-Nuc)

Subject:

[External_Sender] Oyster Creek FHRR Clarification Question 1.a ResponseTekia - The following information provides the response for NRC clarification Question 1.a, as discussed in today's follow-up conference call.

Follow-up Response to Question 1a of the Oyster Creek FHRR Audit Information Request

In Question 1a of the Oyster Creek FHRR Audit Information Request, the NRC sought clarification as to whether structures at the northeast corner of the Reactor Building would permit the conveyance of LIP-generated surface water runoff along the east face of the Reactor Building. Exelon clarified that the area at the northeast corner of the Reactor Building and along the east side of the Reactor Building (between the Reactor Building and the Old Rad Waste Building) is obstructed to flow. The NRC agreed with this clarification but did not agree that the FLO-2D model (updated to replace Area Reduction Factors with raised ground elements to more conservatively account for roof runoff) represented this obstruction. Exelon reviewed the updated model and concur that, when Area Reductions Factors were removed, a gap was inadvertently created between the Reactor Building and Old Radwaste Building, which is occupied by the Drywell Processing Center. The FLO-2D model was corrected to fill this gap with a raise ground element and prevent flow from passing between the buildings, which resulted in a flooding depth of 0.87 foot above the door sill (a 0.36 foot increase) at Door 9. The increase appear s to be the same as the NRC's sensitivity analysis described in the follow-up question. The flooding duration also increased by 0.58 hour6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br />. The table below presents the corrected results for each door location. Exelon is currently preparing an updated LIP calculation to incorporate the correction.

Door No. Reference Grid Element No. Max. Water Surface Station Grade/ Door Sill Elevation Max. Flooding Depth Above the Station Grade/Door Sill Elevation Flooding Duration Above the Station Grade/Door Sill Elevation ft. (NAVD

88) ft. (MSL) Ft (MSL) ft. hrs. Door 1 24458 22.70 22.72 23.50 -0.78 0.00 Door 2 26887 22.75 22.77 23.50 -0.73 0.00 Door 3 23275 22.70 22.72 23.50 -0.78 0.00 Door 4 26895 23.16 23.18 23.50 -0.32 0.00 Door 5 22982 22.70 22.72 23.50 -0.78 0.00 Door 6 27829 23.02 23.04 23.50 -0.46 0.00 Door 7 30020 23.07 23.09 23.50 -0.41 0.00 Door 8 31919 23.20 23.22 23.50 -0.28 0.00 Door 9 26009 24.35 24.37 23.50 0.87 1.52 Door 10 20654 22.62 22.64 23.62 -0.98 0.00 Door 11 20647 22.82 22.84 23.61 -0.77 0.00 2Door 12 19802 23.57 23.59 23.60 -0.01 0.00 Door 13 18978 23.63 23.65 23.69 -0.04 0.00

Please let me know if any additional information is needed.

Thanks.

Dave Distel

This Email message and any attachment may contain information that is proprietary, legally privileged, confidential and/or subject to copyright belonging to Exelon Corporation or its affiliates ("Exelon"). This Email is intended solely for the use of the person(s) to which it is addressed. If you are not an intended recipient, or the employee or agent responsible for delivery of this Ema il to the intended recipien t(s), you are hereby notified that any dissemination, distribution or copying of this Email is strictly prohibited. If you have received this message in error, please immediately notify the sender and permanently delete th is Email and any copies.

Exelon policies expressly prohibit employees from making defamatory or offensive statements and infringing any copyright or any other legal right by Email communication. Exelon will not accept any liability in respect of such communications. -EXCIP Hearing Identifier: NRR_PMDA Email Number: 2594 Mail Envelope Properties (4BCCAD574B0D614096E6221C12ED97D876AD974B)

Subject:

[External_Sender] Oyster Creek FHRR Clarification Question 1.a Response Sent Date: 1/14/2016 10:49:13 AM Received Date: 1/14/2016 10:49:19 AM From: Distel, David J:(GenCo-Nuc)

Created By: David.Distel@exeloncorp.com Recipients: "Joe Bellini" <joe.bellini@aterrasolutions.com>

Tracking Status: None "Samlal, Valmicky:(GenCo-Nuc)" <Valmicky.Samlal@exeloncorp.com> Tracking Status: None "Govan, Tekia" <Tekia.Govan@nrc.gov> Tracking Status: None

Post Office: exchm-omf-24.exelonds.com Files Size Date & Time MESSAGE 3893 1/14/2016 10:49:19 AM Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date: Recipients Received: