ML052500241

Comments on Proposed Directors Decision by Exelon Regarding 2.206 Petition Re Byron Station

ML052500241
Person / Time
Site:	Byron
Issue date:	08/12/2005
From:	Mackellar A Exelon Corp
To:	Dick G Office of Nuclear Reactor Regulation
References
2.206
Download: ML052500241 (5)

Text

,, George Dick - Draft Director's Decision (2.206 Petition)

Page 1 1 George Dick - Draft Director's Decision (2.206 Petition)

Page 1 II From:

<Alison.MacKellarO exeloncorp.com>

To:

<gfd~nrc.gov>

Date:

8/12/05 1:49PM

Subject:

Draft Director's Decision (2.206 Petition)

George, We have reviewed the Draft Director's Decision Regarding the Loop Stop Isolation Valve (2.206 Petition) and do agree that the items documented in the original 2.206 petition are fully addressed.

We have only minor comments that are discussed below and a pdf of which is attached.

1. Page 1, last sentence....... insert the words "could potentially" introduce debris into the reactor coolant system.

2. Page 4, 3rd paragraph........ insert the words "line/nozzle" directly after the words......... pressurizer spray line/nozzle.

3. Page 6, item 4............ same comment as above, insert the words "line/nozzle" directly after the words

.pressurizer spray line/nozzle.

<<2206 comments.pdf>>>

Alison Mackellar Exelon Nuclear Cantera Licensing Engineer (630) 657-2817 pgr (630) 307-3908 alison.mackellar@ exeloncorp.com This e-mail and any of its attachments may contain Exelon Corporation proprietary information, which is privileged, confidential, or subject to copyright belonging to the Exelon Corporation family of Companies.

This e-mail is intended solely for the use of the individual or entity to which it is addressed. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution, copying, or action taken in relation to the contents of and attachments to this e-mail is strictly prohibited and may be unlawful. If you have received this e-mail in error, please notify the sender immediately and permanently delete the original and any copy of this e-mail and any printout. Thank You.

• • • • • • • t********.*************************.*****************

CC:

<joseph.bauer@ exeloncorp.com>, <william.grundmann @exeloncorp.com>

c:\\temp\\GW)OOOO1.TMP Page 1 ii c:\\temp\\GW)00001.TMP Page 1_11 Mlail Envelope Properties (42FCE123.88D: 4: 6285)

Subject:

Draft Director's Decision (2.206 Petition)

Creation Date:

8/12/05 1:48PM From:

<Alison.MacKellar@exeloncorp.com>

Created By:

Alison.MacKellar@exeloncorp.com Recipients nrc.gov owf4.po.OWFN_DO GFD (George Dick) exeloncorp.com william.grundmann CC joseph.bauer CC Post Office Route owf4-po.OWFNDO nrc.gov exeloncorp.com Date & Time 08/12/05 01:48PM Files MESSAGE TEXT.htm 2206 comments.pdf Mime.822 Options Expiration Date:

Priority:

Reply Requested:

Return Notification:

Concealed

Subject:

Security:

Size 1742 3239 264035 369057 None Standard No None No Standard

DD-05-XX UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR REACTOR REGULATION J. E. Dyer, Director in the Matter of

)

Docket No. STN 60-454 Exelon Generation Company, LLC

)

License No. NPF-37 (Byron Station, Unit 1)

)

-)

PROPOSED DIRECTOR'S DECISION UNDER 10 CFR 2206

i. Introduction By electronic mail dated March 2,2005, addressed to Mr. Luls'A. Reyes, Executive Director for Operations at the U.S. Nuclear Regulatory Commission, Mr. Barry Quigley filed a petition pursuant to Title 10 of the Code of Federal Regulations, Section 2206 (Agencywide Document Access and Management System (ADAMS) Accession No. ML050680255). The petitioner requests 1hat the U.S. Nuclear Regulatory Commission (NRC) take enforcement action against Exelon Nucloar's (Exelon's, the licensee's) Byron Station for failure to comply with 10 CFR Part 50, Appendix B, Criterion XVI. Specifically, the petitioner stated that the 1 C cold leg loop stop isolation valve (LSIV) (1 RC8002C) has been' broken for at least six years and has not been repaired. The basis for Ute request is that LSIV I RCBOO2C can be difficult to close, to the point of protective features of the motor actuating. The petitioner indicated that the failure mechanism Is metal-to-metal contact between the valve disc and a misaligned valve guide vhich introdu eebris Into the reactor coolant system.

ENCLOSURE I ZZ':TT sow-rD-removed. The licensee Inspected for loose parts In the vessel and found no loose parts that may have come from the LSIV. As a result, NRC staff finds that the Byron Station, Unit 1 RCS cold leg LSIV i RC8002C is unlikely to be degraded to-a condition where the valve guide, or a portion of the valve guide, can loosen and migrate to the reactor vessel during normal plant operation. Nevertheless, the staff considered the potential for the release of loose parts into the RCS at Byron Station, Unit 1.

In Its May 27, 2005, submItal, the licensee (1) discussed the detection and alerting system that would enable plant personnel to Identify the presence of a large loose part and (2)

'the procedures to be used to Identify and respond to a loose part. Based on a review of the information provided, the NRC staff concludes that the iconsee's loose parts monitoring provision would detect, alarm, and help locate and identify large loose parts. Further, the staff considers it unlikely that a large loose part would be generated coincident with a loss of coolant accident of sufficient size to cause the loose part to become an aggravating factor.

Although small loose parts may be more difficult to detect, they are less likely to cause an immediate safety problem than large loose paris. While considering loose parts, NRC staff postulated two specific situations: (1) a loose part obstructing the chemical and volum system letdown line from the RCS, and (2) a loose part obstructing the pressurizer sp In its May 27, 2005, submittal, the licensee addressed these tWo situations through referencet Section 5.4 of the Byron UFSAR which discusses compliance with Reactor Systems Branch (RSB) Branch Technical Position RSB 5-1, "Design Requirements of the Residual Heat Removal System,' attached to Section 5.4.7 of the NRC Standard Review Plan (NUREG-0800).

RSB 5-1 specifies shutdown requirements for light water reactors. Section 6.4 of the Byron UFSAR shows that Byron has the capability to transition from normal operating conditions to a cold shutdown under al natural circulation scenario without pressurizer spray with limited T T sa

• 'A petition for review on the request for enforcement action for fanure to comply with 10 CFR Part 50, Appendix B, Criterion XVI.

In addressing whether any safety concerns exist regarding operation of Byron Station, Unit 1 In light of the past performance of 1 RC8002C, NiiRC stall considered the previous Information provided by the licensee and the additional informatIon In Its submittal dated May 27, 2005. The staff concludes that the licensee adequately Justified the structural Integrity of the valve guides In 1 RC8002C. With respect to the licensee's loose parts monitoring system and procedures, NRC staff concludes that:

1.

Large loose parts from the Byron Station, Unit 1 cold leg LSIVe hive an acceptably ovo potential of occurrence.

2.

The licensee's loose parts monitoring provisions would detect, alarm, and help locate and Identify large loose parts, including loose parts from LSIV guides.

3.

The licensee has provisions to locate, idenlily, and respond to both large and small loose parts, Including LSIV loose parts.

4.

Because the licensee complies Vith NRC Staff Position RSB -I, NRC staff Is assured that the two LSIV loose-part scenarios postulated for obstruction of tho chemical and

`l volume control system letdown line and for obstruction of the pressurizer spratAill not prevent shutdown of Byron Station, Unit 1.

Exelon has taken actions to assess and develop corrective actions with respect to I RC8002C performance. Development of long-term corrective actions are Included In the Corrective Action Program at the Byron site. The NRC has concluded that in taking the actions as stated earlier, the licensee Is In compliance with tho regulations, The NRC does not have a basis for pursuing enforcement action for failure to comply with 10 CFR Part 50, Appendix B, T

M

.4 p: Il I soz-M-Dsro