ML110260306
| ML110260306 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 01/20/2011 |
| From: | Flores R Luminant Power |
| To: | Ludwig M Office of Nuclear Reactor Regulation, State of TX, Commission on Environmental Quality |
| References | |
| 2130037, 419001, TXX#11010 | |
| Download: ML110260306 (10) | |
Text
Rafael Flores Luminant Power Senior Executive Vice President P 0 Box 1002
& Chief Nuclear Officer 6322 North FM 56 rafaelUflores@Luminant.com Glen Rose, TX 76043 T 254 897 5550 C 817 559 0403 F 254 897 6652 January 20, 2011 CERTIFIED MAIL: 7010 1870 0001 0617 5231 TXX#11010 Texas Commission on Environmental Quality Region 4 2309 Gravel Drive Fort Worth, Texas 76118-6951 Attn:
Ms. Merissa Ludwig Environmental Investigator Comanche Peak Training Center PWS #2130037 Comprehensive Compliance Investigation Findings Response Track #419001
Dear Ms. Ludwig:
This letter and attachment are provided in response to the letter of 13 December 2010 addressing the alleged violation noted at the above referenced Public Water System.
Attached is a summary of corrective actions taken to resolve the alleged violation cited during that investigation.
The Company trusts that the described physical and operational modifications which have been implemented appropriately addresses and resolves the alleged violation noted in the investigation summary. If you require additional information, please contact Mr. David Rutledge at 214-875-8296 or by e-mail david.rutledge@luminant.com.
Sincerely, Rafael Flores By:'k" Mireles DER/attachment A member of the STARS (Strategic Teaming and Resource Sharing) Alliance
-- eDO Callaway
- Comanche Peak
- Diablo Canyon
- Palo Verde - San Onofre-South Texas Project Wolf Creek
Texas Commission on Environmental Quality TXX-11010 Page 2 01/18/2011 xc:
US Nuclear Regulatory Commission Document Control Desk 11555 Rockville Pike Rockville, MD 20852
COMANCHE PEAK TRAINING CENTER PWS #2130037 Alleged Violation:
Failure to hypochlorinate prior to the potable water storage tank in accordance with 30 TAC 290.42(e)(2).
30 TAC 290.42(e)(2)
All groundwater must be disinfected prior to distribution. The point of application must be ahead of the water storage tank(s) if storage is provided prior to distribution.
Permission to use alternate disinfectant application points must be obtained in writing from the executive director.
Background:
Due to the potentially extended residence time in the system's potable storage tank, simple chlorination of raw water when the tank is filled by the operation of the well is not sufficient to assure maintenance of a chlorine residual in the tank, and thus, in the distribution system.
Historically, the chlorine residual has been maintained through manually-initiated recirculation. At the time of the addition of the recirculation line, the hypochlorite feed piping was removed from the inlet piping and connected to the recirculation piping as shown in the attached figure.
Corrective Action:
Since prior experience at start-up of the system has proven that direct hypochlorination of the well pump discharge only is inadequate to maintain a residual in the storage tank, it is imperative that the capacity to inject hypochlorite into the tank recirculation system be maintained. Therefore, the modification implemented maintains the same injection point in the recirculation piping, but provides for automated hypochlorination of raw water passing through this piping.
The recirculation piping is now being left valved in-line with the tank inlet. This valve alignment allows for a free flow of well water to flow to both the tank inlet point as well as to the opposite side of the tank via the recirculation piping. The hypochlorite pump is now controlled through an electrical outlet which is energized at the same time as the well pump when it receives the tank low level signal. Leaving the hypochlorite pump in the "RUN" setting, will result in hypochlorite injection whenever the pump's electrical supply is energized. This results in hypochlorite feed to raw well water prior to the storage tank. With well water entering the tank at two points, some of the raw water will enter the tank unchlorinated, but the tank will always be simultaneously receiving chlorinated water from the other inlet point.
Manual recirculation hypochlorination continues to be performed as needed as it was prior to this alignment.
NOTE: In this alignment, the service pumps are isolated from the recirculation piping to eliminate any potential distribution pressure drops that might occur when the service pumps are operating. By maintaining this alignment, the discharge from the service pumps will be confined to the pressure tank and distribution and there will be no pressure loss due to a discharge back to the storage tank.
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COMANCHE PEAK TRAINING CENTER PWS #2130037 The attached photos, and drawing, (figure 1), show the recirc line where the chlorine is added to the system. The flow from the well is split and goes both directions through the recirc line adding chlorine when the well is pumping. A receptacle on the wall was discovered to be wired to start the chlorine addition pump when the well is running, and injecting chlorine as required. The connection of the chlorine pump to the recirc line, instead of the line from the well is superior, because it also allows for addition of chlorine when the well is not operating, by allowing the use of a recirc pump and recirc configuration. Since the well will sometimes go nearly a month without adding water to the tank, this ability to add chlorine when the well is not pumping is critical to maintaining adequate chlorine residual.
This photo shows the south side of the tank with the recirc line entering the tank
Flow Direction is me recirc tine as it goes arouna me tank irom me soum to me west siae
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1 Flow Direction This is the recirc line coming around the tank from the west side to the north side
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Hypochlorite Feed Line h
J Flow Direction The recirc line on the north side of the tank, showing the chlorine addition connection
Hypochlorite Feed Line r
Inlet/Recirc "T": Inlet flows to Tank Inlet and Recirc Pipe at this point.
Recirc Pipe is hypochlorinated L
Flow Direction in Recirc Pipe (behind containment)
Flow Direction Well Ilet Pipe i ne otner ena or me recirc line. I ne pipe in tne miaame iert is wnere tne wei aaas water to the system. Notice that if necessary to provide flow in both directions to the tank, that the valve in the lower right may be throttled or closed to insure chlorine addition via the recirc line to the tank.