ML110970435
| ML110970435 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs, 05200016  |
| Issue date: | 03/23/2011 |
| From: | Calvert Cliffs, Constellation Energy Group |
| To: | Office of New Reactors |
| Quinn, L, NRO/DSER/RAP2, 301-415-2220 | |
| References | |
| +reviewedjr | |
| Download: ML110970435 (20) | |
Text
Horseshoe Crab Impingement Reduction at Calvert Cliffs Power Plant Unit 1 and Unit 2 Presented to JEC, March 23, 2011 1
Basic Horseshoe Crab Guard Design Concept yPlace an obstacle in the path of migrating horseshoe crabs to divert them away from CCNPP Intake.
Note:
The two guard designs being proposed are held in position with cables attached to existing structures above the waterline, and rest on the bottom within the Intake Forebay Enclosure. Both designs are temporary/
portable and deployed seasonally only when horseshoe crabs are most abundant.
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Presentation Objectives
- Determine permit requirements, if any, for proposed work inside our Intake Bay Enclosure?
y Determine actions needed to complete the proposed work, including any permitting in time for the 2011 H
h C
b ti t
ti i
M Horseshoe Crab mating season starting in May.
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Horseshoe Crab Guard Project Objectives (1) Reduce mortality of horseshoe crabs that result from impingement and handling on the trash racks.
(2) Reduce work load required to handle live and dead h
h b
d f h
h k
horseshoe crabs removed from the trash racks.
(3) Reduce number of horseshoe crabs that get into the condenser water boxes to improve thermal performance, and to reduce probability of tube pitting on Unit 1.
(4) Reduce number of horseshoe crabs that get into Saltwater System (check valves).
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Horse Shoe Crab Behavior y The vast majority of horseshoe crab movement consist of crawling on the bottom.
y Though rare adult horseshoe crabs can swim. However they typically only in a half loop when they encounter d t t
li b t ti h
th and start crawling over an obstruction as shown on the next slide.
y Interview of a diver (Scott Hewitt of Coastal Marine Sciences Inc.) who has 30 years experience and has worked in areas where horseshoe crabs cover the bottom around bridge pilings (example: Near Slaughter Beach Delaware) reported he had never seen them on a vertical surface.
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Horseshoe Crab Swim Pattern Ref. E. D. VOSATKA Department of Zoology, The Ohio State University, Columbus, Ohio 432102 7
Seasonal Removable Fence Panel Horseshoe Crab Guard Figure 2 Mean sea level Mean high waterline 1.14 Mean low waterline 0.10 8
Seasonal Removable Fence Panel Horseshoe Crab Guard Figure 3 9
Seasonal Removable Fence Panel Horseshoe Crab Guard Figure 4 10
Seasonal Removable Horseshoe Crab Guard Box Figure 5 11
Seasonal Removable Horseshoe Crab Guard Box Figure 6 East Face of Intake Structure 12 Intake forebay enclosure bottom Flow
Seasonal Removable Horseshoe Crab Guard Box Figure 7 13
Proposed Horseshoe Crab Guard Locations for 2011 Figure 1 Mean high waterline 1.14 Mean low Existing Bulkhead Water depth at Intake Structure face 26 mean high 14 long each 14 Flow waterline 0.10 face -26 mean high Approximate depth -
43 mean high Approximate depth -45 mean high Shore line North Fence panel guard Approximate length 760
Issues to be Resolved y Determine if permits for work within CCNPP Intake Forebay Enclosure are required?
y If permits required, actions needed to ensure work can be accomplished by May 2011 breeding season?
can be accomplished by May 2011 breeding season?
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QUESTIONS?
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CENG Contacts y Bradley R Wright Sr. Engineering Analyst CCNPP (410)495-4005 y Brenda Nuse Sr. Environmental Specialist CCNPP (410) 495-4913 y Jim Burkman Sr. Environmental Specialist Environmental Services (410) 787-5130 17