ML20076J255
| ML20076J255 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 06/15/1983 |
| From: | Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE, YANKEE ATOMIC ELECTRIC CO. |
| To: | Knighton G Office of Nuclear Reactor Regulation |
| References | |
| SBN-520, NUDOCS 8306200397 | |
| Download: ML20076J255 (4) | |
Text
e 1671 Worcesser Rood Pub 5c SoMce of New Hampshire wns
.W e 01701 (617) - 872 - 8100 June 15, 1983 SBN-520 T.F. B7.1.2 United States Nuclear Regulatory Commission Washington, D. C. 20555 Attention:
Mr. George W. Knighton, Chief Licensing Branch No. 3 Division of Licensing Refere nc es :
(a) Construction Permits CPPR-135 and CPPR-136, Docket Nos. 50-443 and 50-444 (b) PSNH Letter, dated February 24, 1983, "Open Item
Response
(SRP 11.5; Effluent Treatment Systems Branch)",
J. DeVincentis to G. W. Knighton
Subject:
Supplemental Open Item Response:
(SER Section 11.5.2; Meteorological and Effluent Treatment Systems Branch) l
Dear Sir:
We have enclosed a supplemental response to the open item regarding the need for a gross radioactivity monitor in the Service Water System.
l The enclosed response will be incorporated in OL Application Amendment 50 l
(RAI 460.35(F) and appropriate FSAR Section).
1 Please notify me if additional information is required to resolve this open item.
Very truly yours, l
YANKEE ATOMIC ELECTRIC COMPANY lUcYf ZC f r$
J. DeVincentis
- 1. -
Project Manage ALL/fsf k
cc: Atomic Safety and Licensing Board Service List 8306200397 830615 PDR ADOCK 05000443 E
PDR 1000 Elm St., P.O. Box 330, Manchester, NH O3105 Telephone (603) 669-4000 TWX 7102207595
e We have performed calculations to evaluate the need for a radiation monitor in the Seabrook Servicy Water System (SWS). Since Seabrook does not discharge effluents from the Radioactive Liquid Waste System into the SWS, and since the SWS does not provide direct cooling to any systems that are normally radioactive, and also since alternate means as described below are available to detect a PCCW/SWS leak with a sensitivity equal to that of a SWS radiation monitor, we do not believe there is a need for a SWS radiation monitor.
The function of the Service Water System is to transfer heat loads from the following sources:
(1) Condenser water box priming pump seal water heat exchangers, (2) Secondary Component Cooling Water heat exchangers, (3) Diesel generator jacket water coolers, and (4) Primary Component Cooling Water heat exchangers.
These heat loads, from both the primary and secondary portions of the plant, are transferred to the ultimate heat sink via the SWS. The SWS takes suction from and discharges to the transition structure of the Circulating Water System.
None of the systems listed above are normally radioactive. However, the Primary Component Cooling Water (PCCW) System could possibly become radioactively contaminated should a tube leak occur in one of the PCCW heat exchangers or coolers which contain reactor coolant. This occurrence would be detected by an increasing level in the PCCW surge tank and by the PCCW System radiation monitors. The affected component would then be isolated and repaired. For the SWS to become contaminated, an additional tube failure in the PCCW/SWS heat exchanger would have to occur.
Assuming that the PCCW System had become contaminated, calculations have been performed assuming various PCCW activities and various PCCW/SWS leak rates.
Because of the relatively high SWS flow rates,3either the PCCW activity has to be exceptionally high (on the order of 1 x 10- uc/cc), or the PCCW/SWS leak rate has to be excessive to result in SWS activities which could be detected l
by a SWS radiation monitor.
l l
Any leakage from the PCCW System will result in a decrease in PCCW head tank liquid level. Because of the limited volume (less than 2,000 gallons) monitored in the head tank, leakage from the PCCW System will readily be noticed by the operator during his routine observation of the Main Control Board or by low level alarms associated with the head tank liquid level.
Additionally, in lieu of a SWS radiation monitor, a rate-of-change alarm, indicating a decreasing PCCW head tank liquid level, will be installed which l
will provide the operator with an alarm in the Main Control Room. This alarm l
will be set based on anticipated PCCW activities such that a PCCW/SWS leak, resulting in SWS activities at least equal to the minimum sensitivity of a SWS radiation monitor, will be detected within one hour.
i i
I L
For example: at a PCCW System activity of 1 x 10-4 ue/ce, it would take a PCCW/SWS leak of about 100 gal /hr to result in a SWS activity of about 1 x 10-6 uc/ce, which is the minimum sensitivity of a SWS radiation monitor. A loss of 100 gallons from the PCCW head tank represents about 5 percent of the indicated liquid level. A loss of 5 percent level in the head tank can be readily detected by the level instrumentation and rate-of-change circuitry. In fact, the circuitry is capable of detecting leak rates approximately 10 times smaller.
However, normal system temperature fluctuations, which may occur temporarily during system operation, may lead to erroneous alarms if the rate-of-change alarm is set too low.
Therefore, the value of the rate-of-change alarm will have to be determined af ter operating experience has been obtained. For whatever value is utilized for the rate-of-change alarm, an appropriate value of PCCW System activity will be used to assure that this leak detection system provides a sensitivity equal to or greater than a SWS radiation monitor.
Based upon the above, the following commitments are made:
1.
The SW and PCCW Systems will be sampled weekly.
2.
With activity in the PCCW System 2: 1 x 10 -3 uc/ce, the SWS will be sampled daily.
3.
With the PCCW System radiation monitor inoperable, the SW and PCCW Systems will be sampled daily.
4.
With a confirmed PCCW/SWS leak and PCCW activity 2 1 x 10-4 uc/cc, the SWS will be sampled once every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
5.
The setpoint on the PCCW head tank liquid level rate-of-change alarm will be set to ensure that its sensitivity to detect a PCCW/SWS leak is equal to or greater than that of an SWS radiation monitor, located in the unit's combined SWS discharge, with an LLD of 1 x 10-6 ue/cc.
If this sensitivity cannot be achieved, the SWS will be sampled once every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
We feel that the above commitments applied in conjunction with the described rate-of-change level circuitry provides an equal or better alternative to a SWS radiation monitor.
If you have any further questions, please feel free to contact us.
Rep. Beverly Hollingworth Ms. Olive L. Tash Coastal Chamber of Commerce Designated Representative of 209 Winnacunnet Road the Town of Brentwood Hampton, NH 03842 R.F.D. 1, Dalton Road Brentwood, NH 03833 William S. Jordan, III, Esquire Harmon & Weiss Edward F. Meany 1725 I Street, N.W.
Designated Representative of Suite 506 the Town of Rye Washington, DC 20006 155 Washington Roac Rye, NH 03870 Roy P. Lessy, Jr., Esquire Office of the Executiv-Legal Director Calvin A.
Canney U.S. Nuclear Regulatory Commicsion City Manager Washington, DC 20555 City Hall 126 Daniel Street Robert A. Backus, Esquire Portsmouth, NH 03801 1
116 Lowell Street P.O. Box 516 Dana Bisbee, Esquire Manchester, NH 03105 Assistant Attorney General Office of the Attorney General Philip Ahrens, Esquire 208 State House Annex Assistant Attorney General Concord, NH 03842 Eepartment of the Attorney General Augusta, ME 04333 Anne Verge, Chairperson Board of Selectmen Mr. John B. Talizer Town Hall Designated Representative of South Hampton, NH 03842 the Town of Hampton 5 Morningside Drive Patrick J. McKeon Hampton, NH 03842 Selectmer.'s Office 10 Central Road Roberta C. Pevear Rye, NH 03870 Designated Representative of the Town of Hampton Falls Ruthanne G. Miller, Esquire l
Drinkwater Road Law Clerk to the Board Hampton Falls, NH 03844 Atomic Safety and Licensing Board U.S. Nuclear Regulatory Commission Mrs. Sandra Gavutis Washington, D.C.
20555 Designated Representative of the Town of Kensington Dr. Maury Tye, President RFD 1 Sun Valley Association East Kingston, NH 03827 209 Summer Street Haverhill, MA 01830 Edward J. McDermott, Esquire 1
l Sanders and McDermott Mr. Angie Machiros Professional Association Chairman of the Board of Selectmen 408 Lafayette Road Town of Newbury Hampton, NH 03842 Newbury, MA 01950 Jo Ann Shetwell, Esquire Assistant Attorney General Environmental Protection Bureau Department of the Attorney General One Ashburton Place, 19th Floor Boston, MA 02108 i
~. -,. - -. - -,.... -. -. - _.
_