ML20209C652

Forwards Hydrologic Engineering Input to Draft Ser.Input Contains Many Open Items Because Response Not Received to 830708 Request for Addl Info.Open Items Listed

ML20209C652
Person / Time
Site:	Satsop
Issue date:	12/15/1983
From:	Johnston W Office of Nuclear Reactor Regulation
To:	Novak T Office of Nuclear Reactor Regulation
References
CON-WNP-1463 NUDOCS 8312230306
Download: ML20209C652 (25)

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DEC 15 1983 Docket No. 50-508 MEMORANDUM FOR: Thomas M. Novak, Assistant Director for Licensing, DL FROM: William V. Johnston, Assistant Director Materials, Chemical & Environmental Technology, DE

SUBJECT:

HYDROLOGIC ENGINEERING INPUT TO THE WNP-3 DRAFT SER Plant Name: Washington Public Power Supply System Nuclear Project No. 3 Licensing Stage: OL Responsible Branch: Licensing Branch No. 3; A. Vietti, PM Requested Completion Date: November 29, 1983 Enclosed is our Hydrologic Engineering input to the WNP-3 draft SER. This input was prepared by R. Gonzales who can be reached at extension 28018.

We have received no responses to our questions which you submitted to the applicant on July 8,1983; consequently, this input contains many open items.

In addition, Section 2.4.13, Accidental Release of Liquid Effluents, is not being provided at this time. This section will be provided following receipt

, from the Effluent Treatment Systems Section of a listing of the inventory in

! the tank that has the greatest potential for offsite concentration of nuclides in the event of a release.

This input contains the following open items:

1) The adequacy of site grading to prevent flood levels from ponding higher than door elevations (Section 2.4.2).

2) Ponding of water on a safety related roof (Section 2.4.2).

l W 8312230306 031215 ADOCK 05000 e j

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• Thomas M. Novak DEC 15 1983

3) Capability of dewatering system to maintain groundwater levels at pre-determined elevation (Section 2.4.12).

4) Proposed dewatering system surveillance program (Section 2.4.12).

Q/ (q w V <ML O' William V. Johnston, Assistant Director Materials, Chemical & Environmental Technology Division of Engineering

Enclosure:

As stated cc: w/o enclosure R. Vollmer w/ enclosure R. Ballard W. Gammill C. Willis G. Knighton A. Vietti M. Fliegel R. Gonzales DISTRIBUTION:

Dockets EHEB Rdg WVJohnston DE:EHk DEJIE$ DE HE DE ADMCET RGonzales:ws MHFliegel BaYard WVJohnston 12/f&/83 12/jf/83 12/i/83 12////83

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HYDROLOGIC ENGINEERING INPUT TO THE WASHINGTON PUBLIC POWER SUPPLY SYSTEM NUCLEAR PROJECT NO. 3 DRAFT SER DOCKET NUMBER 50-508 2.4 Hydrologic Engineering The staff has reviewed the hydrologic engineering aspects of the applicant's design, design criteria, and design bases for safety-related facilities at the Washington Public Power Supply System Nuclear Project No. 3 (WNP-3). The acceptance criteria used as a basis for staff evaluations are set forth in SRP 2.4-1 through 2.4-14 (NUREG-0800). These acceptance criteria include the applicable GDC reactor site criteria (10 CFR 100), and standards for protection against radiation (10 CFR 20, Appendix B, Table II). Guidelines for implementation of the requirements of the acceptance criteria are provided in RGs, ANSI standards, and Branch Technical Positions (BTPs) identified in SRP 2.4-1 through 2.4-14. Conformance to the acceptance criteria provides the bases for concluding that the site and facilities meet the requirements of 10 CFR 20, 50, and 100 with respect to hydrologic engineering.

2.4.1 Hydrologic Description WNP-3 is located in Satsop, Washington, approximately 1.4 miles south of the Chehalis River near the confluence of the Satsop River. The site is about 26 miles west of Olympia and about 16 miles east of Aberdeen, Washington.

As shown on Figure 2.4-1, WNP-3 is situated on a ridge between Workman Creek and the Chehalis River.

The Chehalis River which heads in the Willapa hills in southwest Washington, flows generally eastward to the city of Chehalis where it changes its course abruptly to the north. About 10 miles north of Chehalis, near Grand Mound, the river flows northwesterly to Elma, then west to Grays Harbor at Aberdeen.

The river and its tributaries have a drainage area of about 2,115 mi2. The drainage area at the site, including the Satsop River, is about 1,765 mi2, The average annual flow at this location is about 6,820 cfs. The Chehalis River basin is shown on Figure 2.4.2.

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The major tributaries of the Chehalis River in the vicinity of the site are the Satsop and Wynocchee Rivers. The Satsop River has a drairage area of about 2

300 mi and an average annual flow of about 2030 cfs. The Wynoochee River has a drainage area of about 100 mi 2 and an average annual flow of about 1200 cfs.

Both of these tributaries rise on the south side of the Olympic Mountains and flow southward to their confluences with the Chehalis River. A number of small tributaries to the south of the Chehalis River head in the hills .

surrounding the site. These include: Elizabeth Creek, Hyatt Creek, Fuller Creek, Purgatory Creek and Workman Creek. All of these streams are relatively short, intermittant streams, originating at elevations between 300 to 400 ft above mean sea level (MSL).

As shown on Figure 2.4.2 there are two dams and associated reservoirs on the tributaries of the Chehalis River. The Wynocchee dam and lake, which is a Corps of Engineers project, provides water supply for industry and agriculture and storage for flood control. The lake also offers recreation opportunities for the public. The Skookumchuck dam and rese~rvoir project is operated by the Pacific Power and Light Company (PP&L"). The reservoir provides make-up water for PP&L's Centralia Steam Electric Station.

The water resources of the Chehalis River valley include both surface and ground supplies. Within 5 miles of the plant, surface water permits have been granted by the Washington State Department of Ecology to about 78 users. Most surface water is used for irrigation, with the remainder for domestic use, livestock l watering, fish propagation, fire protection and industrial use. Except for a single domestic water user located within a mile downstream of the plant, there are no known users of Chehalis River water for domestic purposes between the plant and Grays Harbor.

1 Groundwater in the Chehalis River valley is obtained from shallow wells which

, tap the alluvial aquifer and is used mostly for drinking and irrigation.

There are 45 known wells within 2 miles of the plant. Five major municipal water systems within 20 miles of the site are served partially or totally by groundwater.

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The applicant has provided hydrologic descriptions of the plant site and vicinity. The staff has reviewed the applicant's information in accordance with procedures in SRP 2.4.1. The staff concludes that the requirements of GDC-2 and 10 CFR Part 100, with respect to general hydrologic descriptions, have been met.

2.4.2 Floods 2.4.2.1 Flood Design Considerations Five potential sources of site flooding were considered by the applicant:

(1) intense local precipitation on the plant yard; (2) floods on the Chehalis River; (3) dam failures; (4) surges and seiches; (5) tsunamis.

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The staff has reviewed the material presented by the applicant in accordance with procedures in SRP 2.4.2 and concludes that in addition to these five l flooding sources, other sources of potential flooding of the plant site are the small creeks near the site. Since the applicant did not address potential

! flooding from these small creeks, the staff made an independent evaluation as described in Section 2.4.3.

l 2.4.2.2 Effects of Local Intense Precipitation j

At WNP-3, a site drainage system consisting of catch basins, drain pipes, and ditches has been provided to carry surface runoff- south to Workman Creek l and north to the Chehalis River via Fuller and Purgatory Creeks. The drainage l

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system is designed for a 100 year recurrence st'orm with pipes flowing half-full.

The intensity of this storm is 2.9 in. per hour. This is less than the probable maximum precipitation (PMP) so during a PMP event, some water could pond on the site.

PMP is the estimated depth of precipitation (rainfall) for which there is virtually no risk of exceeding. At WNP-3, the PMP values used by the applicant for durations of 1 through 6, 12, 24, and 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> are as follows:

Duration Incremental PMP Total PMP (hrs) (in.) (in.)

1 4.32 4.32 2 1.92 6.24 1

3 2.24 8.48 6' 6.24 14.72 12 5.44 20.26 24 5.12 25.28 48 3.00 28.28 These PMP values were determined from Technical Paper 40 (U.S. Weather Bureau,.

1963). Although Technical Paper 40 does not present PMP estimates, it does give a method for determining PMP values from 100 year rainfall values which are given'in the paper. The applicant states that the 100 year rainfall values used to obtain the PMP values above, are more conservative than those given in NOAA Atlas No. 2, Volume IX-Washington (NOAA,1973). In addition, these PMP values are also more conservative than those given in Hydrometeorological Report 43 (U.S. Weather Bureau, 1966).

The staff has reviewed the three PMP references used by the applicant and

, agrees that Technical Paper 40 results in more conservative PMP estimates than the other two references. The staff concludes that the PMP values used

, by the applicant are appropriate for the evaluation of site and roof drainage.

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l The minimum elevation of openings to safety-related structures is 390.5 ft MSL. The elevation of the paved road that surrounds the plant is 390.0 ft and the grassed areas within this road are at elevation 389.5 ft MSL. Because the grassed areas are 1 ft lower than openings to safety related structures, water could pond 1 ft deep in these areas before any structure or equipment would be affected.

Using the PMP rainfall values tabulated above, the applicant estimated the maximum depth of ponding in the grassed areas would be 2.0 inches assuming that the site drainage system is functioning as designed. The applicant states in the FSAR, that in the unlikely event that any drain is completely blocked, rainwater could pond to elevation 390 ft MSL, which is the elevation of the crown of the surrounding access road. Subsequent runoff would overflow the road to lower-lying areas. Since exterior door openings are at elevation 390.5 ft MSL, the applicant concluded that water from local intense precipita-tion would not enter safety related buildings.

The staff has reviewed the material presented by the applicant and concludes that the applicant has not provided sufficient information to support its conclusion that local floods will not enter safety-related buildings.

From topographic maps provided by the applicant, it appears that because the areas to the south, east and west slope upward from the plant; water could pond to a higl.er elevation than the top of the access road, possibly entering safety-related structures.

The staff will require that the applicant identify the areas where water will pond before overflowing the access road and the areas where water will drain-to "

once it overflows the road. In identifying these areas, obstructions to flow such as temporary and permanent buildings, trailers, sheds, etc., should also be shown. It should also be assumed that all of the site drainage system is blocked. Once flow areas have been identified, the applicant should provide l assurances that the flow areas are of sufficient capacity to prevent water from ponding to excessive levels. The applicant should also discuss whether the fence which surrounds the site will adversely obstruct flows.

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In discussing the effects of local intense precipitation on roofs of safety-related buildings, the applicant stated that the roof drainage system is designed for a 100 year recurrence storm at 50 percent capacity. With the (ception of a roof section adjacent to the steam tunnel, safety-related buildings have parapets that are 12 inches above the roof high points and 18 inches above the low points. Thus the average depth of ponding would be about 15 inches. The applicant states that roofs are designed to support the load induced by up to 15.4 inches of water.

The roof section adjacent to the steam tunnel at elevation 417.5.ft MSL is surrounded by walls to elevation 443.5 ft MSL or higher. The applicant stated that this roof is capable of supporting the load induced by a 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> PMP plus the 100 year snow pack. This is equal to 28.28 inches of rainfall plus a snow-depth water e'quivalent of 3.78 inches or 32.06 inches.

The applicant does not state whether the surrounding walls are equipped with scuppers or other means of limiting water depths. Therefore, it is possible -

that water could pond to a much greater depth than 32.06 inches because the walls are at least 26 ft high (443.5 ft - 417.5 ft). The applicant should thus consider rainfall for durations greater than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. The effect of a 26 ft depth of water should be addressed unless it can be demonstrated that water cannot physically pond to this depth. Alternately, the applicant should consider putting scuppers (or other devices) in walls to limit water depths to those that can be supported safely by the roof section adjacent to the steam tunnel.

The staff has reviewed the material presented by the applicant in the FSAR, using the procedu.es described in SRP Section 2.4.2. Based on this review, the staff concludes that the applicant has not provided sufficient information to support its conclusions that ponded water will not enter safety-related buildings or that the roof section adjacent to the steam tunnel is capable of supporting potential rainfall loads. Thus the staff cannot conclude at this time, that the plant meets the requirements of GDC-2 with respect to flooding by intense. local precipitation.

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l The staff, however, does conclude that during a PMP event, water levels on ' ,

roofs of safety related structures will remain at or below the levels determined by the applicant except for the roof adjacent to the steam tunnel.

2.4.3 Probable Maximum Flood on Streams and Rivers The Probable Maximum Flood (PMF) is defined as the hypothetical precipitation-induced flood that is considered to be the most severe reasonably possible.

Severe rainfall storms in western Washington occur mostly in the winter months when there is snow on the ground. Consequently, the applicant estimated the PMF for the Chehalis River based on PMP and snowmelt over the drainage basin.

As a first step in estimating the PMF, the applicant subdivided the Chehalis River drainage basin into three subbasins and developed individual unit hydrographs for each subbasin esing Corps of Engineers procedures. A flood hydrograph was then developed for each subbasin using the Corps of Engineers flood hydrograph computer program, HEC-1. To determine a PMF for each subbasin, each hydrograph was then increased by the average annual river flow to account for base flow conditions. The three individual PMF's were then routed, where appropriate, and combined at the site to form a single PMF.

To account for potential antecedent flood conditions as recommended in RG 1.59, the applicant assumed that a storm equal to 50 percent of the PMP would occur three days prior to the PMP storm. The antecedent flood resulting from these conditions was combined with the PMF at the site. The resultant

, hydrograph had a peak discharge of 353,300 cfs.

i l PMF water levels in the Chehalis River adjacent to the site were determined by means of the Corps of Engineers HEC-2, " Water Surface Profiles" computer l program. The PMF discharge (353,000 cfs) stillwater level was estimated l to be 53.1 ft MSL. The applicant determined that coincident wind-wave l activity would result in a maximum wave runup, including wind setup, of l 23.1 ft. Adding this to the PMF stillwater level resulted in a maximum flood i

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level of 76.2 ft MSL. Since the plant is at elevation 390 ft MSL, the applicant concluded that no safety-related structures would be affected by a PMF on the Chehalis River.

The applicant did not address the potential for flood.ing from the small creeks near the site; however, based upon the following observations, the staff concluded that floods on these small creeks will not affect the safety of the plant.

Workman Creek which runs south of the plant has a stream bed elevation which is more than 200 ft lower than the plant grade elevation. Because the drainage.

area of this creek is small, less than 10 mi 2, the staff concludes that a PMF would not rise 200 ft in the creek. In addition to Workman Creek, there are two other creeks in the vicinity, Fuller Creek and Purgatory Creek. Both of these have drainage areas of less than one mi' and each creek flows away from the plant. The staff thus concludes that floods on these creeks will not affect the safe operation of WNP-3.

At the CP stage, the staff reviewed the applicant's analyses and the effects of coincident wind-wave activities. The staff concurred then with the applicant's analyses and concluded that there is no potential danger to safety-related structures due to the PMF with coincident waves. The staff has reviewed the FSAR material presented by the applicant in accordance with procedures described in SRP 2.4.2 and 2.4.3. Based on this review, the staff concludes that the plant meets the guidelines of RG 1.59, " Design Basis Floods for Nuclear Power Plants", and the requirements of GDC-2 with respect to flooding from the Chehalis River and the small creeks adjacent to the site.

2.4.4 Potential Dam Failures As'shown in Figure 2.4.2, the only dam located upstream of the plant is Skookumchuck Dam. The applicant estimated the effect of a failure of this dam coincident with a Standard Project Flood (SPF) equal to one-half of the PMF, It was assumed that the reservoir would be full at the time the dam

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failed. Using Corps of Engineers procedures, the applicant estimated a dam-failure hydrograph with a peak discharge of 260,000 cfs. This nydrograph was routed downstream and combined with SPF's from the Chehalis River sub-basins.

The resultant peak flow at the site was determined to be 182,000 cfs. Using the same procedures as were used to determine PMF levels, the applicant determined the flood level at the site due to failure of Skookumchuck dam would be 39.6 ft ms1. Since this elevation is less than the PMF level, the applicant concluded that failure of Skookumchuck Dam will not affect the safety of the plant.

The staff reviewed the applicant's dam failure analysis at the CP stage and concluded that there would be no flooding of the plant due to dam failures.

The staff has reviewed Section 2.4.4 of the FSAR, using the procedures described in SRP 2.4.4. The staff concurs that conservative procedures have been used and that potential dam failures pose no threat to the plant.

Thus the staff concludes that the plant meets the requirements of GDC-2 and 10 CFR 100, Appendix A, with respect to flooding by dam failures.

2.4.5 Probable Maximum Surge and Seiche Flooding There are no historical seiche records at Grays Harbor, the largest body of water near the site, and the probability of seiche occurrence at Grays-Harbor is extremely remote due to the shallow tidal flats. The plant site located at River Mile 21 and elevation 390 ft MSL is not susceptible to surge or

'seiche flooding.

2.4.6 Probable Maximum Tsunami Flooding WNP-3 is located about 30 miles inland from the Pacific Ocean with all safety-related equipment at an elevation of 390 ft MSL or higher. The maxi-mum historical tsunami wave height originating within 1000 miles of the site was 32.8 ft and occurred in Cook Inlet, Alaska, in 1901. The most damaging tsunami of local origin, for the Washington coast area, was generated by the Alaskan Earthquake of 1964 (epicenter more than 1000 miles from the site), and caused

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minor damage at the Ocean Shores Development which is located on the spit th'at protects the Grays Harbor entrance. The elevation of the highest wave was 13.3 feet MSL; causing a break in the sand dune dike and the deposition of winter storm debris along the spit. There was no ovetopping of the spit and no flooding resulted at Aberdeen.

The applicant estimated that a probable maximum tsunani (PMT) approaching the Chehalis River through Grays Harbor would result in only a 3.5 ft increase in water level at the mouth of the Chehalis River. The effects of the PMT would be reduced to negligible heights at the plant site because of attenuation in .

the river channel.

The staff has reviewed the applicant's tabulation of historical tsunami and its estimate of the PMT at the site. Based on procedures in SRP 2.4.6, the staff concludes that no credible tsunami event could threaten the plant.

Thus, the requirements of GDC-2 as it relates to structures, systems and components important to safety being designed to withstand the effects of tsunami, have been met. .

2.4.7 Ice Effects The Pacific ocean, which is about 30 miles west of the site, greatly influences the climate in the WNP-3 area. The ocean acts to moderate the seasonal and daily variability in climate throughout the year such that winters are warmer than at other locations at similar latitudes. Because of this, there are no conditions which might produce a permanent ice cover or ice jam on the Chehalis River. In addition, because of the large difference in elevation

( between the Chehalis River and the plant (Section 2.4.3), even if ice jams did form, floods resulting from these jams would not affect the safe operation of the plant.

Water required for normal operation of WNP-3 will be supplied from groundwater infiltration-type structures (Ranney Wells). Therefore, potential icing will not affect the normal plant water supply. Emergency safe shutdown and cool

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Q down of WNP-3 can be accomplished using the ultimate heat sink which consists of dry cooling towers located adjacent to the reactor auxiliary building.

Make-up water is not required for the dry cooling towers and during periods of low temperature the design of the towers prevents freezing of the tower or pipelines.

The staff has reviewed the information provided by the applicant concerning ice effects, in accordance with procedures in SRP 2.4.7. The staff concludes that icing will not affect the safe operation of the plant.

2.4.8 Cooling Water Canals and Reservoirs T.'.cre are no safety-related or other cooling water canals or reservoirs associated with WNP-3.

2.4.9 Channel Diversions The Chehalis is a meandering river that shows a number of former channel locations, oxbows and sloughs in the vicinity of the plant (see Figure 2.4.1).

As described in Section 2.4.11.1, the source of makeup water for the WNP-3 cooling tower is the alluvial aquifer that underlies the Chehalis River floodplain. Recharge to the aquifer occurs all across the river valley as well as in the river channel and from the 70 to 80 inches of annual rainfall in the area. The aquifer reacts much like a reservoir by accepting and storing surface inflow during periods of high river flows and high rainfall and releasing the stored water when rainfall and river flows aren't as plentiful. Since the aquifer is recharged by both rainfall and the river across the entire valley it is possible for the river channel to meander considerably before the makeup water capability would be affected.

Water for plant use is withdrawn from the aquifer by means of two Ranney wells located as shown on Figure 2.4.1. As part of the design to place Ranney collectors in the floodplain, the adjacent river banks are being stabilized

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to minimize erosion. However, because the Chehalis is a meandering river, displaying oxbows and sloughs, diversion affecting the Ranney wells is still considered possible. Regardless of the availability of the Ranney wells, the safety of the plant will not be jeopardized because, as described in Section 2.4.11.2, emergency cooling of the plant can be accomplished using the ultimate heat sink, which consists of a dry cooling tower.

The staff thus concludes that potential channel diversions, although remote, present no safety related hazard to the plant and that the requirements of 10 CFR Part 100, relative to channel diversions, have been met.

2.4.10 Flood Protection Requirements As described in Section 2.4.3, the staff concluded that the plant is located considerably higher than any credible flood in the Chehalis River. However, in Section 2.4.2, the staff concluded that the applicant had not provided sufficient information to support its conclusion that local intense precipita-tion will not enter safety-related buildings. Additionally, it is not evident that a roof section adjacent to the steam tunnel has been designed to support potential ponded rainfall. The applicant will be required to provide additional information in support of its conclusions. Resolution of these issues will be addressed in a supplement to this SER.

2.4.11 Cooling Water Supply '

2.4.11.1 Normal Water Supply Under normal operating conditions, waste heat will be dissipated to the atmosphere by a natural draft cooling tower. Makeup water to replace the water lost by evaporation, blowdown and drift, will be supplied to the cooling tower by two Ranney wells located in the alluvial aquifer which underlies the Chehalis River valley (see Figure 2.4.1). To prevent excessive buildup of dissolved solids in the cooling system, a certain amount of cooling water

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cooled down by a supplemental cooling facility. The blowdown discharge will be diluted in the river through the use of a submerged multiport diffuser.

The maximum makeup water requirement for WNP-3 is approximately 18,000 gpm (40.0 cfs), and a single Ranney well is capable of supplying this amount on a continuous basis. The capability of the Ranney wells to supply this '

quantity of water is independent of low flows in the Chehalis River. The State Energy Facility Site Evaluation Council (EFSEC), hcwever, has -

administrative 1y established that plant makeup withdrawal (except for a hot-standby maintenance flow of 2 cfs) must cease when the daily river flow '

goes below 550 cfs. Additionally, plant withdrawal may not exceed the difference between the river flow and 550 cfs. The long-term annual average flow of the Chehalis River at the site is estimated to be about 6820 cfs.

The estimated average monthly flows vary from 730 cfs in August to 14,900 cfc in January. The minimum and maximum historical flows at the site are estimated to be about 400 and 97,100 cfs, respectively.

• Because of the water withdrawal limitation established by the EFSEC, the plant will have to be shut down whenever the daily river flow goes below 550 cfs.

The applicant estimates that, on the average, this will occur about four days a year.

The applicant has completed a contract with the city of Aberdeen to purchase releases of 62 cfs of flow from the Wynoochee Reservoir to supplement the Chehalis River during low flow periods. This water is to be used to mitigate

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adverse impacts associated with the consumptive use of river water.

The staff has reviewed the material presented by the applicant and concludes that neither drought periods nor the conditions established by the EFSEC, regarding withdrawal of water for plant use, will unduly restrict the availability of cooling water for normal operations as required by GDC-44.

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2.4.11.2 Emergency Water Supply Emergency safe shutdown and cooldown of WNP-3 can be accomplished using the ultimate heat sink which consists of a dry cooling tower located adjacent to the reactor auxiliary building. The UHS is also used for heat rejection during normal operation and shutdown. The UHS is comprised of two independent i 100 percent capacity trains. Each train has a cooling tower of the air-cooled heat exchange type, with Component Cooling Water System (CCWS) fluid passing through the tube side and ' air over the exterior surface of the tubes. The cooling tower fans cycle on and off and through low and high speeds auto-matica11y during all operating modes to maintain the desired temperature.

The UHS is capable of operating under a range of heat loads during normal -

and emergency conditions. With a dry bulb ambient temperature of 101.5*F, -

each train has a design heat rejection capability of 180 x 106 Btu /hr with ,

11,000 gpm CCWS flow entering the cooling tower at 153*F and leaving at 120*F.

• Durin0 normal operation, the VHS in conjunction with the CCWS heat exchanger can reject the normal heat loads while maintaining CCWS temperatures at or below 95*F. For accident conditions the VHS is designed to reject the maximum accident heat loads without the need for additional cooling by the CCWS heat  ;

exchanger. By operating the fans at' full speed, one cooling tower can maintain the CCWS temperature at or below 120*F during accident conditions. .

5 As suggested in R.G. 1.27, the applicant analyzed the 30-day pgriod following l a design basis accident. This analysis showed that each cooling tower is [

capable of diss,ipating the maximum heat load following a LOCA. By maintaining [

the temperature of the water exiting the cooling tower at 120*F or less, the [

maximum heat rejected during the 30 day analysis, was 133 x 106 Btu /hr. Since the cooling tower has a design heat rejection capability of 180 x 106 Btu /hr,  !

t the applicant concluded that the UHS is capable of providing adequate coaling i i

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S for at least 30 days. The applicant thus concluded that the UHS meets the recommendations set forth in R.G.1.27 and thus the requirements of GDC 44 with respect to thermal aspects of the heat transfer system.

The staff has not completed its review of the UHS so a conclusion on its acceptability cannot be made at this time. '

2.4.12 Groundwater 2.4.12.1 Groundwater Conditions -

i The plant area is underlain by the Astoria Formation which is a thick (2500 to 3000 feet) deposit of relatively impermeable tertiary sandstones. This formation dips northward toward the Chehalis River and forms the most extensive geologic unit at the site. All Category I structures are fcunded in the Astoria sand-stone approximately 2000 feet above its base. North of the plant and south of the Chehalis River, pleistoce,ne terrace deposits overlie the Astoria Formation. These deposits consist mostly of sands, gravels and silts. Further north, the Chehalis River valley is underlain by alluvial materials. The Ranney wells which supply the cooling water required for normal operation of the plant are founded in these alluvial materials.

In the site area, groundwater is found in the Astoria Formation, the pleistocene deposits and in the alluvial materials in the Chehalis River floodplain. The Astoria Formation has very low permeability and permits only small amounts of recharge and minimal groundwater movement. Because of this, it is not a productive groundwater source. The groundwater table beneath the plant site area follows the ground topography and is parallel to the weathered and unweathered zones of the Astoria sandstone. The groundwater slopes northward toward the Chehalis River. Prior to construction of the plant, the groundwater level was at an elevation of about 380 feet MSL.

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Groundwater also occurs in a discontinuous manner in the pleistocene terrace deposits. Recharge is derived from infiltration of rainfall on the areas above the terrace levels and infiltration from the Chehalis River. There are no known major aquifers within these deposits and only three donestic wells tap '

the terrace groundwater in small perched aquifers.

The only satisfactcry source of groundwater in the site vicinity occurs in the alluvial aquifer that underlies the Chehalis River valley. This aquifer extends downward from about 10 ft below the ground surface to about 165 ft.

The high permeability and transmissivity coefficients of this unconfined aquifer indicate that the aquifer reacts much like a reservoir ano a hydraulic conduit. Recharge to the aquifer occurs all across the river valley as well as in the river channels from the 70 to 80 inches of annual precipi.tation in the area and from the high surface inflow from the widespread Chehalis River basin. The aquifer accepts surface water for storage during these periods until the uncerground storage is full. The permeable aquifer discharges readily into streams and rivers during periods of low flow. The alluvial aquifer is limited horizontally by tertiary sandstone sedimer.ts on the south side of the river and by the-southern edge of the Olympic Mountains on the north side of the valley. The aquifer extends two miles across the Chehalis River valley, about 14 miles downstream to Grays Harbor and about 15 miles upstream to the eastern limit of Grays Harbor County. As described in Section 2.4.11.1, this aquifer will be used to supply makeup water to the plant.

2.4.12.2 Dewatering System A permanent groundwater drainage system (GWDS) that operates solely by gravity has been installed around the WNP-3 reactor auxiliary building (RAB). The, GWDS consists of vertical 6 inch diameter half-round drain pipes spaced at 8.5 ft intervals around the RAB at the interface between the rock and exterior concrete walls. The vertical pipes, which drain the surrounding rock, extend '

from plant grade to the base of the foundation mat except at the west side of the RAB where the vertical drain pipes extend into the turbine building, four

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feet above the flocr elevation of 390 ft msl, This elevation is above the highest level (3 ft) that the applicant ht.s estimated circulating water could rise, in the event of a Circulating Water System break inside the building.

Thus any water released into the Turbir.a Building would be prevented from directly entering the @DS.

Groundwater that seeps into the vertical drain pipes is conveyed to a 8 inch diameter horizontal drain plpe located along the periphery of th.e mat.

Collected groundwater is then routed to a 6 ft diameter drainage tunnel that drains into a small tributary Of Warhnan Creek south of the plant. In addition, 8 inch diameter perforated undermat drains have been placed diag 9nally b neath the foundation mat. These undermat firains are also connected to the drainage tunnels, Manholes are provided at each corner cf the RA8 to allow for periodic inspection and cleanir.g of the GWOS, The GWOS is not classified as a seismic Category I system except for the manholes at the corners of the RAB.and the upper 5 ft of the extended vertical drain pipes at the west side wall of the RAB. The manholes are seismic Category I to provide access to the horizontal drain pipe ar.d to the drainage tunnel in the event of an earthquake. The upper portions of the vertical drain pipes are seismically qualified to resist the passive pressure of the sandstone on the embedded portion of the pipes and to resist the peak seismic '

acceleration of the RAB at grade elevation.

The applicant has stated that in the unlikely event of a complete blockage of the GWDS, the walls and foendation mat of the RAB are designed to withstand the resulting hydrostatic load of a grounowater level at elevation 365 ft msl.

This elevation is 39 ft above the bottom of the mat, elevation 326 ft msl, and 25 ft below the plant grade elevation of 395 ft ms1. The applicant states that in the event of a complete blockage of the GWDS, there would be sufficient time to repair the system before the surrounding groundwater would rise to an elevation of 355 ft msl. This time was estimated to be a minimum of 115 days.

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Using the procedures in SRP 2.4.12 including Branch Technical Position (BTB)

HGEB-1, the staff ha:; reviewed the information provided by the applicant in the FSAR. The staff concludes that there is inadequate information with which to assess the applicant's conclusion that in the event of a complete failure of the dewatering system there will be sufficient time to repair the system before the surrounding groundwater would rise to an unacceptable level. The staff has asked the applicant to provide additional information concerning the dewatering system. Until the staff receives the requested information, it cannot determine whether the plant design meets the criteria of BTP HGE6-1

. of SRP 2.4.12 or the requirements of GDC-4 with respect to the dewatering system.

The applicant considered a break in the underground Circulating Water System (CWS) pipe and its effect on the ability of the dewatering system to maintain water levels below elevation 365 ft MSL. The applicant stated that if a major bteak in the CWS pipe was to occur, water would be forced upward out of the trench in whic.h it lies, and would be drained away from the surface by storm drains.

The staff has reviewed the information provided by the applicant according to procedures described in BTP W3EB-1 in SRP 2.12, and concludes that insufficient information has been provided by the applicant,'concerning the effect of postulated pipo breaks on the dewatering system. The staff has submitted questions t.o the applicant on the subject of pipe breaks. The staff will complete its review pending receipt of responses from the applicant concern-ing the effect of pipe breaks on the dewatering system.

In Section 2.4.4 of the CP-SER, the staff stated that the applicant had cormitted to monitor groundwater levels at the walls of the reactor auxiliary building and to radiologically monitor discharges through the groundwater drainage cystem. The applicant proposed to do this by installing one piezometer at each reactor auxiliary building wall, located between the manholes and 10 feet from the wall. 1his instrumentation was to provide an

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. i alarm in the control room if a specified level was exceeded. The monitoring program proposed by the applicant in the FSAR is considerably different than that proposed at the CP stage. The applicant did not indicate in the FSAR if any part or all of the CP stage monitoring program will be used during plant operation; instead, it stated that in-service surveillance of the vertical-drains, horizontal-headers, and the drain tunnels will be made at 90 day intervals during the wet season. The vertical drains will be tested by dropping a light down the drain to the horizontal header and observing the light from the manholes through the header. The horizontal headers will De inspected by shining a light at one end of each header and observing it from the other end. The drainage tunnel will be inspected by walking along it from the manhole to the concrete plug and looking through the concrete plug to daylight.

The staff agrees that this surveillance program will effectively indicate whether the dewatering system is functioning and whether there is any blockage.

However, it will not be effective if there is standing water in the vertical drains. The applicant should explain if any part or all of the monitoring program committed to in the CP-SER is to be used to monitor the performance of the dewatering system during operation. If it is not to be used, the applicant should explain why not. In any event, the applicant should describe the procedures to be used to monitor groundwater levels in the event that there is standing water in the vertical drains.

The staff has reviewed the information provided by the applicant and concludes that it cannot complete its review of the dewatering syst.em because the applicant has not provided sufficient information to assess the following:

(1) The time for groundwater levels to rebound to the hydrostatic design level of 326 ft MSL in the event of a complete failure of the dewatering system.

(2) The adequacy of the in-service monitoring program.

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• . (3) The effects of pipe-breaks on the dewatering system. -

The staff has submitted questions to the applicant and will complete its review pending receipt of responses to those questions.

2.4.13 Accidental Release of Liquid Effluents (To be provided later) 2.4.14 Technical Specifications and Emergency Operation Requirement Because the staff has not yet completed its Hydrologic Engineering review, the need for technical specifications and/or emergency operation requirements has not been determined at this time.

2.4.15 Conclusions According to procedures outlined in the SRP, the staff has reviewed the design of WNP-3 with regard to hydrologically and hydraulically-related plant safety features. On the basis of this review, the staff concludes that large-scale river or stream floods do not pose a threat to the safe operation of the plant or the integrity of the site. The staff, howaver, is unable to conclude that local flooding will not threaten the plant. The staff concludes that WNP-3 meets the requirements of GDC 2 with respect to potential flood hazards except for the outstanding item concerning local flooding.

The staff has reviewed the availability of water for normal cooling purposes during diminished flow periods in the Chehalis River and the conditions imposed by the EFSEC. The staff concludes that there is sufficient water available to maintain safe plant operaticn over any reasonable drought period as required by GDC 44 with respect to normal cooling water availability.

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The staff has reviewed the information on the dewatering system presented by the applicant and concludes that there is insufficient information concerning the time it would take for,the groundwater level to rise to an unacceptable level in the event of a total failure of the dewatering system. There is also not ecough information concerning the effect of pipe breaks on the dewatering system nor on the proposed in-service monitoring program. The staff will '

' complete its review of the dewatering system once the applicant addresses the concerns stated in this draft SER and provides responses to the questions which have already been provided to the applicant.

In addition, the staff has not conpleted its review of the performance of the ultimate heat sink. This review is being conducted by Argonne National Laboratories and the results will be presented'in the SER.

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• s DISTRIBUTION

. -n1.dep546)'7" NRC PDR PRC System LB#3 Reading JLee Avietti DEC 0 81983 GWKnighton TMNovak Attorney, OELD Docket No.: 50-508 MEMORANDUM FOR: Joseph Rutberg, Assistant Chief Hearing Council / Antitrust Counci1 FROM: George W. Knighton, Chief Licensing Branch No. 3 Division of Licensing

SUBJECT:

APPROVAL OF WASHINGTON PUBLIC POWER SUPPLY SYSTEM fiUCLEAR PROJECT N0. 3 (WNP-3), DES-OL STAGE Enclosed for your approval is the DES-OL stage for WNP-3. This DES provides the second assessment of the environmental impact associated with WNP-3.

Copies of the DES were circulated to the Branches that contributed input and concurrence has been received by the Assistant Directors.

I Please indicate your concurrence by signing below and contact the Project Manager (Annette Vietti, x24449) for pickup not later than COB, December 14, 1983.

u.,qam ~;~:.. Ly GCap W. n.:4.. 3 George W. Knighton, Chief Licensing Branch No. 3 Division of Licensing

Enclosure:

As stated cc: D. Hassell I concur with WNP-3 DES-OL SEriai ru401 tsai2GG ~

PDR ADOCK 05000508 D PDR

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Dock:t No.: 50-508 MV 2 9 lE3L PDR NRC PDR PRC System MEMORANDUM FOR: H. Denton LB#3 Reading - I

. E. Case Attorney, OELD J. Carter JLee -

D. Eisehhut .

AVietti i R. Purple GWKnighton l H. Thompson 1

R. Vollmer l R. Mattson ~

T. Spets J. Sniezek T. Ippolito T. Novak G. Lainas F. Miraglia TH8B: George W. Knighton, Chief, Licensing Branch No. 3. DL FROM: Annette Vietti, Project Manager, Licensing Branch No. 3, DL

SUBJECT:

DAILY HIGHLIGHT WNP-3 On October 25, 1983, representatives from Washington Public Power Supply System management met with the staff to discuss the status of the ongoing review of the WNP-3 Final Safety Analysis Report (FSAR) in view of the delay in construction

, until an assured source of funding is available. The Supply System stated they would continue completing plant design and dedicating the resources available l to resolve regulatory concerns that may affect design. However, due to the current project delay, they believe developing a revised schedule for the remaining review of WNP-3 is appropriate. The staff requested that the Supply System management provide the NRC with the revised fuel load data for WNP-3.

By letter dated November 18, 1983, the Supply System infonned the staff that it would take 42-48 months after restart to complete construction of WNP-3. Restart of construction could occur as early as January,1984. Therefore, for planning purposes the earliest projected fuel load date for WNP-3 is June, 1987. The Supply System requested that in order to benefit from the considerable work effort by both the Supply System and the NF.C staff thus far, preparation of the draft SER documenting the review to date should continue with a slightly delayed issuance date. This would allow the Supply System to address an additional number of cur-rently outstanding round one questions before issuance of the DSER. The Supply System provided a recomended schedule for DSER accomplishment.

A schedule to accomplish the remaining review of WNP-3 is currently under review by the staff.

Original s!rned by:

Anneits '!!ad i

A D bOkO dhos t

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PDR Annette Vietti, Project Manager Licensing Branch No. 3. DL l

cc: S. Black y l Ett a ton n /u /83 s 3 /73/83